ENTOMOLOGICAL RESEARCH, Issue 3 2007
Elena N. ELPIDINA
Abstract Digestion in Tenebrio molitor larvae occurs in the midgut, where there is a sharp pH gradient from 5.6 in the anterior midgut (AM) to 7.9 in the posterior midgut (PM). Accordingly, digestive enzymes are compartmentalized to the AM or PM. Enzymes in the AM are soluble and have acidic or neutral pH optima, while PM enzymes have alkaline pH optima. The main peptidases in the AM are cysteine endopeptidases presented by two to six subfractions of anionic proteins. The major activity belongs to cathepsin L, which has been purified and characterized. Serine post-proline cleaving peptidase with pH optimum 5.3 was also found in the AM. Typical serine digestive endopeptidases, trypsin-like and chymotrypsin-like, are compartmentalized to the PM. Trypsin-like activity is due to one cationic and three anionic proteinases. Chymotrypsin-like activity consists of one cationic and four anionic proteinases, four with an extended binding site. The major cationic trypsin and chymotrypsin have been purified and thoroughly characterized. The predicted amino acid sequences are available for purified cathepsin L, trypsin and chymotrypsin. Additional sequences for putative digestive cathepsins L, trypsins and chymotrypsins are available, implying multigene families for these enzymes. Exopeptidases are found in the PM and are presented by a single membrane aminopeptidase N-like peptidase and carboxypeptidase A, although multiple cDNAs for carboxypeptidase A were found in the AM, but not in the PM. The possibility of the use of two endopeptidases from the AM , cathepsin L and post-proline cleaving peptidase , in the treatment of celiac disease is discussed. [source]

Characterization of spore appendages from Bacillus cereus strains

JOURNAL OF APPLIED MICROBIOLOGY, Issue 5 2001
T. Stalheim
Aims:,Further characterization and comparison of spore appendages from Bacillus cereus strains. Methods and Results:,Appendages were isolated from 10 B. cereus strains from the food industry and food-borne outbreaks. The appendage proteins were dissolved in sample buffer containing 2% SDS and 5% mercaptoethanol at 100°C, and subjected to SDS-PAGE. None of the appendages showed identical protein patterns. Western blots, using antibodies raised against a 3·5 kDa appendage protein, showed that the majority of the appendage proteins reacted with the antibody. Removal of the appendages by sonic treatment of the spores did not alter their heat resistance. The appendages were digested by proteinase K, pepsin, and the enzymes in the detergent Paradigm 10, but not by trypsin or chymotrypsin. Spore adhesion to stainless steel was scarcely affected by removal of the appendages. Digestion of adhered intact spores (with appendages) with Paradigm 10 showed a high degree of variation. Conclusions:,Spore appendages from B. cereus are complex proteinaceous structures that differ among strains. Significance and Impact of the Study:,Information about spore appendages and their involvement in spore adhesion is crucial for improving cleaning methods used for control of bacterial spores in the food industry. [source]

PCR-RFLP genotypes associated with quinolone resistance in isolates of Flavobacterium psychrophilum

JOURNAL OF FISH DISEASES, Issue 3 2007
S Izumi
Abstract A novel genotyping method for epizootiological studies of bacterial cold-water disease caused by Flavobacterium psychrophilum and associated with quinolone resistance was developed. Polymerase chain reaction followed by restriction fragment length polymorphism (PCR-RFLP) was performed on 244 F. psychrophilum isolates from various fish species. PCR was performed with primer pair GYRA-FP1F and GYRA-FP1R amplifying the A subunit of the DNA gyrase (GyrA) gene, which contained the quinolone resistance determining region. Digestion of PCR products with the restriction enzyme Mph1103I showed two genotypes, QR and QS. The difference between these genotypes was amino acid substitutions at position 83 of GyrA (Escherichia coli numbering). The genotype QR indicated an alanine residue at this position associated with quinolone resistance in F. psychrophilum isolates. Of the 244 isolates tested in this study, the number of QR genotype isolates was 153 (62.7%). In isolates from ayu (n = 177), 146 (82.5%) were genotype QR. With combination of this technique and previously reported PCR-RFLP genotyping, eight genotypes were observed in F. psychrophilum isolates. Using this genotyping system, the relationships between genotype and host fish species, or locality of isolation, were analysed and are discussed. [source]

Polymorphisms in the sequences of Marteilia internal transcribed spacer region of the ribosomal RNA genes (ITS-1) in Spain: genetic types are not related with bivalve hosts

JOURNAL OF FISH DISEASES, Issue 6 2005
B Novoa
Abstract Marteilia refringens is a protozoan parasite causing a disease notifiable to the Office International des Epizooties (OIE) and its distribution has implications for the transfer of live animals. The internal transcribed spacer-1 (ITS-1) from Marteilia clones contains polymorphism. Digestion with HhaI reveals two different restriction profiles, previously referred as ,O' (Marteilia from oyster or Marteilia refringens) and ,M' (Marteilia from mussels or Marteilia maurini). The aim of the present work was to determine whether the two previously described Marteilia molecular types (O and M) exist in the Iberian Peninsula and the strictness of the association with their bivalve host species. The sequence variability in the ITS-1 of Marteilia species was studied in mussels, Mytilus galloprovincialis, and flat oysters, Ostrea edulis, from different geographical locations in Spain, to establish the existence and the distribution of different species or molecular types. Although there were two distinct evolutionary lineages that corresponded more or less strictly with the ,M' and ,O' types, it was evident from the estimated phylogeny that some ,O' types have switched to ,M' type, and vice versa. Moreover, ,O' types were found in mussels and ,M' types were found in oysters, which suggests that there have been several cross-species transmissions of Marteilia between mussels and oysters. [source]

Effects of Various Fiber Additions on Lipid Digestion during,In Vitro,Digestion of Beef Patties

JOURNAL OF FOOD SCIENCE, Issue 9 2009
S.J. Hur
ABSTRACT:, The purpose of this study was to examine the effect of various fiber additions on lipid digestion during the,in vitro,digestion of beef patties. The control patties were prepared with 90.5% lean meat and 9.5% tallow. Treatments consisted of 90% lean meat with 9.5% tallow and either 0.5% cellulose, 0.5% chitosan, or 0.5% pectin. The beef patties were then passed through an,in vitro,digestion model that simulated the composition of the mouth, stomach, and small intestine juices. The change in structure and properties of the lipid droplets was monitored by laser scanning confocal fluorescence microscopy. In general, there was a decrease in lipid droplet diameter as the droplets moved from mouth to stomach to small intestine. The amount of free fatty acid dramatically increased after,in vitro,digestion in all beef patties. The amount of free fatty acid was, however, lower in beef patties containing chitosan and pectin than other beef patties after,in vitro,digestion. Beef patties containing various fibers had lower thiobarbituric acid-reactive substances (TBARS) values than samples with no fibers. Among the samples to which fibers were added, chitosan and pectin had lower TBARS than beef patties with cellulose. The cholesterol content decreased after,in vitro,digestion in all beef patties but was not different among the beef patties before and after,in vitro,digestion. These results enhance our understanding of the physicochemical and structural changes that occur to ground beef within the gastrointestinal tract. [source]

Determination of the small cell lung cancer associated biomarker pro-gastrin-releasing peptide (ProGRP) using LC-MS

JOURNAL OF SEPARATION SCIENCE, JSS, Issue 2 2007
Bjørn Winther
Abstract Small cell lung cancer is a rapidly growing neoplasm with high mortality. A recently discovered biomarker, pro-gastrin-releasing peptide (ProGRP), is used as a specific diagnostic marker for the disease. The present methods of quantification are based on the immunoassay techniques RIA and ELISA. Our object was to develop an LC-MS method for the detection and quantification of ProGRP using specific tryptic digestion products from the recombinant peptide ProGRP (31,98), a sequence common to three isoforms of ProGRP. The conditions for enzymatic cleavage were optimized and MS compatibility was obtained. Digestion of ProGRP (31,98) yielded an array of peptide products and these were evaluated for further method development. The peptide product NLLGLIEAK proved to be the preferable candidate to monitor ProGRP due to signal intensity, column retention, and peptide specificity. The identity of this product was verified by means of LC-MS/MS and the linearity of the calibration curve evaluated. LOD was calculated to be 13.9 pg on column (O.C.). Plasma samples spiked with ProGRP (31,98) prior to digestion verified the suitability of this digest product for the determination of ProGRP. LC-MS may prove to be a valuable tool for biomarker mediated diagnosis in the future. [source]

Digestion and Assimilation of the Free-living Nematode Panagrellus redivivus Fed to First Feeding Coregonid Larvae: Evidence from Histological and Isotopic Studies

JOURNAL OF THE WORLD AQUACULTURE SOCIETY, Issue 1 2005
Christian Schlechtriem
The free-living nematode Panagrellus redivivus is a potential source of live food for first feeding fish. The digestion and assimilation of nematodes by larval fish were investigated with the aid of a histological and stable isotope approach. Larvae of whitefish Coregonus lavaretus were reared for 8 d with nematodes and compared with an unfed control. Nematodes were readily ingested by 3-d-old larvae. Different stages of nematode digestion could be observed in transverse sections of fish larvae sampled on Day 6 at regular intervals after feeding. Nematodes were produced on corn medium. In this way nematodes with a stable carbon isotope signature clearly different from the isotopic pattern of the fish larvae could be obtained. Stable carbon isotope signatures for lipids and lipid-free matter of fish larvae sampled on Days 2 and 8 after first feeding were clearly influenced by the stable isotopic pattern of the nematodes. The high acceptance of the nematodes by Coregonus lavaretus larvae and the early onset of digestion and nutrient retention positively confirm the potential of PanagreUus redivivus as a live food for first feeding fish larvae. [source]

Distributed intraclot thrombolysis: mechanism of accelerated thrombolysis with encapsulated plasminogen activators

JOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 9 2004
J. K. Leach
Summary.,Background: The delivery of encapsulated plasminogen activators has demonstrated enhanced thrombolysis in vivo in several models. The mechanism of such improvement has not previously been established. Objectives We explored in vitro the mechanism by which microencapsulation of streptokinase in polymeric microparticles accelerates clot digestion and reduces reperfusion times by as much as an order of magnitude in vivo. Methods: The efficacy of microencapsulated streptokinase (MESK) was directly compared with identical dosages of unencapsulated streptokinase (FREE SK) at three initial pressure drops using clots formed of plasma or whole blood in 0.2-cm inner diameter glass capillary tubes. Results: MESK demonstrated accelerated flow restoration compared with FREE SK for each condition in plasma (23.8 ± 4.5% faster) and whole blood clots (17.2 ± 9.2% faster). Images collected by light microscopy show sites of thrombolysis internal to the clot only with MESK while the spatial distribution of fluorescently labeled streptokinase by confocal microscopy confirms greater penetration of the encapsulated agent compared with unencapsulated streptokinase. Digestion thus proceeds in three dimensions rather than restricted to a two-dimensional lysis front. Conclusions: The improved clot penetration with MESK establishes enhanced transport with encapsulation and the concept of distributed intraclot thrombolysis as a basis for the accelerated dissolution observed with encapsulated plasminogen activators in vivo. [source]

Distribution and characterization of hemolytic activity by an oral anaerobe from the Streptococcus milleri group

MOLECULAR ORAL MICROBIOLOGY, Issue 2 2004
T. Yamaguchi
Some oral anaerobes from the Streptococcus milleri strain group were found to secrete human specific hemolytic toxin, which was detected when bacteria were cultured in Todd-Hewitt broth and Brain Heart Infusion broth. The toxin elicited by the Streptococcus intermedius strain was partially fractionated by ammonium sulfate precipitation. Preincubation with glutathione or cysteine showed significant inhibiting effects; however, no effects were seen with dithiothreitol or ,-mercaptoethanol, and cholesterol was a weak inhibitor. Five kinds of protease inhibitor had no effect on the hemolytic activity, and rabbit preimmune and immune sera against the bacterial cells showed weak inhibition at a similar level. Digestion with trypsin, chymotrypsin, proteinase-K, subtilisin and pronase-P brought about a rise in activity, followed by a decrease during long-term incubation. Other enzymes tested showed no effects. Further, the presence of the intermedilysin gene in the portion with hemolytic activity was not identified by polymerase chain reaction. [source]

Digestion in the common marmoset (Callithrix jacchus), a gummivore,frugivore

AMERICAN JOURNAL OF PRIMATOLOGY, Issue 12 2009
Michael L. Power
Abstract Wild common marmosets (Callithrix jacchus) feed on fruits, insects, and gums, all of which provide different digestive challenges. Much of the ingested mass of fruits consists of seeds. In general, seeds represent indigestible bulk to marmosets and could inhibit feeding if they are not eliminated rapidly. In contrast, gums are ,-linked polysaccharides that require microbial fermentation. Their digestion would benefit from an extended residence time within the gut. Earlier research found that mean retention time (MRT) for a liquid digestive marker (cobalt EDTA) was significantly longer than MRT for a particulate marker (chromium-mordanted fiber), suggesting that common marmosets preferentially retain liquid digesta. We conducted two four-day-long digestion trials on 13 individually housed adult common marmosets fed a single-item, purified diet in order to examine the relations among MRT of cobalt EDTA and chromium-mordanted fiber, food dry matter intake (DMI), and apparent digestibility of dry matter (ADDM). We compared the MRT values with the data from the previous study mentioned above and a study using polystyrene beads. There were no significant correlations among MRT, ADDM, or DMI, although increases in DMI between trials were associated with decreases in MRT. ADDM was consistent within individuals between trials; but the mean values ranged from 75.0 to 83.4% among individuals. We found no difference in MRT between the liquid (17.5±1.6,hr) and particulate (17.9±1.4 hr) markers. Although these values were not significantly different than found previously, the MRT for chromium-mordanted fiber tended to be longer. This probably reflects the relatively small size of the chromium-mordanted fiber particles used in this study. An inverse relationship between particle size and MRT was evident; the mean MRT of polysterene beads, the largest marker, was only 8.3±1.5,hr. Marmosets appear to retain liquids and small particles within the gut longer than large particles. Am. J. Primatol. 71:957,963, 2009. © 2009 Wiley-Liss, Inc. [source]

A Light-Driven DNA Nanomachine for the Efficient Photoswitching of RNA Digestion,

ANGEWANDTE CHEMIE, Issue 12 2010
Mengguang Zhou
Photonen als Treibstoff: Über die Photoregulierung der topologischen Struktur eines DNAzym/RNA-Komplexes gelingt das vollständige An- und Ausschalten des RNA-Verdaus auf der Ebene eines einzelnen Moleküls. Die Schlüsselbestandteile des Photoschalters sind Azobenzoleinheiten. [source]

Involvement of Iron (Ferric) Reduction in the Iron Absorption Mechanism of a Trivalent Iron-Protein Complex (Iron Protein Succinylate

BASIC AND CLINICAL PHARMACOLOGY & TOXICOLOGY, Issue 3 2000
Kishor B. Raja
Iron protein succinylate is a non-toxic therapeutic iron compound. We set out to characterise the structure of this compound and investigate the importance of digestion and intestinal reduction in determining absorption of the compound. The structure of the compound was investigated by variable temperature Mössbauer spectroscopy, molecular size determinations and kinetics of iron release by chelators. Intestinal uptake was determined with radioactive compound force fed to mice. Reduction of the compound was determined by in vitro incubation with intestinal fragments. The compound was found to contain only ferric iron, present as small particles including sizes below 10 nm. The iron was released rapidly to chelators. Digestion with trypsin reduced the molecular size of the compound. Intestinal absorption of the compound was inhibited by a ferrous chelator (ferrozine), indicating that reduction to ferrous iron may be important for absorption. The native compound was a poor substrate for duodenal reduction activity, but digestion with pepsin, followed by pancreatin, released soluble iron complexes with an increased reduction rate. We conclude that iron protein succinylate is absorbed by a mechanism involving digestion to release soluble, available ferric species which may be reduced at the mucosal surface to provide ferrous iron for membrane transport into enterocytes. [source]

Removal of poly-histidine fusion tags from recombinant proteins purified by expanded bed adsorption

BIOTECHNOLOGY & BIOENGINEERING, Issue 4 2005
N. Abdullah
Abstract Enzymatic methods have been used to cleave the C- or N-terminus polyhistidine tags from histidine tagged proteins following expanded bed purification using immobilized metal affinity chromatography (IMAC). This study assesses the use of Factor Xa and a genetically engineered exopeptidase dipeptidyl aminopeptidase-1 (DAPase-1) for the removal of C-terminus and N-terminus polyhistidine tags, respectively. Model proteins consisting of maltose binding protein (MBP) having a C- or N-terminal polyhistidine tag were used. Digestion of the hexahistidine tag of MBP-His6 by Factor Xa and HT15-MBP by DAPase-1 was successful. The time taken to complete the conversion of MBP-His6 to MBP was 16 h, as judged by SDS,PAGE and Western blots against anti-His antibody. When the detagged protein was purified using subtractive IMAC, the yield was moderate at 71% although the overall recovery was high at 95%. Likewise, a yield of 79% and a recovery of 97% was obtained when digestion was performed with using "on-column" tag digestion. On-column tag digestion involves cleavage of histidine tag from polyhistidine tagged proteins that are still bound to the IMAC column. Digestion of an N-terminal polyhistidine tag from HT15-MBP (1 mg/mL) by the DAPase-I system was superior to the results obtained with Factor Xa with a higher yield and recovery of 99% and 95%, respectively. The digestion by DAPase-I system was faster and was complete at 5 h as opposed to 16 h for Factor Xa. The detagged MBP proteins were isolated from the digestion mixtures using a simple subtractive IMAC column procedure with the detagged protein appearing in the flowthrough and washing fractions while residual dipeptides and DAPase-I (which was engineered to exhibit a poly-His tail) were adsorbed to the column. FPLC analysis using a MonoS cation exchanger was performed to understand and monitor the progress and time course of DAPase-I digestion of HT15-MBP to MBP. Optimization of process variables such as temperature, protein concentration, and enzyme activity was developed for the DAPase-I digesting system on HT15-MBP to MBP. In short, this study proved that the use of either Factor Xa or DAPase-I for the digestion of polyhistidine tags is simple and efficient and can be carried out under mild reaction conditions. © 2005 Wiley Periodicals, Inc. [source]

Decoding epithelial signals: critical role for the epidermal growth factor receptor in controlling intestinal transport function

ACTA PHYSIOLOGICA, Issue 1 2009
D. F. McCole
Abstract The intestinal epithelium engages in bidirectional transport of fluid and electrolytes to subserve the physiological processes of nutrient digestion and absorption, as well as the elimination of wastes, without excessive losses of bodily fluids that would lead to dehydration. The overall processes of intestinal ion transport, which in turn drive the secretion or absorption of water, are accordingly carefully regulated. We and others have identified the epidermal growth factor receptor (EGFr) as a critical regulator of mammalian intestinal ion transport. In this article, we focus on our studies that have uncovered the intricate signalling mechanisms downstream of EGFr that regulate both chloride secretion and sodium absorption by colonocytes. Emphasis will be placed on the EGFr-associated regulatory pathways that dictate the precise outcome to receptor activation in response to signals that may seem, on their face, to be quite similar if not identical. The concepts to be discussed underlie the ability of the intestinal epithelium to utilize a limited set of signalling effectors to produce a variety of outcomes suitable for varying physiological and pathophysiological demands. Our findings therefore are relevant not only to basic biological principles, but also may ultimately point to new therapeutic targets in intestinal diseases where ion transport is abnormal. [source]

Trials update in wales

CYTOPATHOLOGY, Issue 2007
A. Fiander
Three ongoing studies will be presented and discussed. Prevalence of Human Papillomavirus Infection in a South Wales Screening population Methods: A total of 10 000 consecutive, anonymous liquid based cytology screening samples were collected over a five month period in 2004. Age, cytology result and social deprivation score was provided for each specimen. The methodology was chosen to ensure inclusion of all women attending routine cervical screening, avoiding potential constraints associated with obtaining individual informed consent. The liquid based cytology samples were processed and reported by the receiving cytology laboratory and the residual specimens sent to the HPV Research Laboratory, Wales College of Medicine, where they were processed and stored at -80°C until analysis. High risk and low risk HPV Typing was undertaken using PCR , EIA (Jacobs et al 1997). Full high risk typing was performed on HPV positive specimens. Results: The study population had a mean age of 38 years with 92% negative, 5% borderline and 3% dyskaryotic cytology. The average social deprivation score was 17.4 (based upon the Welsh Index of multiple deprivation). The following results will be presented: HPV prevalence by age. HPV prevalence by cytology result. Type specific HPV prevalence in single and multiple infection. Conclusion: This study represents the largest type specific HPV Prevalence Study in the UK to date. As such it will form a useful base line against which to access performance of marketed HPV tests and evaluating the impact following implementation of HPV vaccination. [Funded by Welsh Office for Research and Development] CRISP , 1 Study (Cervical Randomized Intervention Study Protocol -1) Background: Indole-3-carbinol (I3C) and Diindolylmethane (DIM) are found in cruciferous vegetables and have been identified as compounds that could potentially prevent or halt carcinogenesis. I3C spontaneously forms DIM in vivo during acid digestion. I3C has been shown to prevent the development of cervical cancer in HPV 16 transgenic mice and both I3C and DIM have been shown to promote cell death in cervical cancer cell models. DIM is the major active bi-product of I3C and preliminary data indicate that DIM is active in cervical dysplasia and may be better tolerated than I3C. Aim: To investigate chemoprevention of high grade cervical neoplasia using Diindolylmethane (DIM) supplementation in women with low grade cytological abnormalities on cervical cytology. Objectives: To observe any reduction in the prevalence of histological proven high-grade cervical intraepithelial neoplasia (CIN) after 6 months of supplementation. ,,To observe any reduction in the prevalence of cytological abnormalities. ,,To observe any changes in the clinical appearance of the cervix. To assess acceptability and monitor any side effects of DIM supplementation. ,,To assess whether any benefit is seen in relation to Human Papillomavirus (HPV) status including HPV Type, Viral load and integration. Methods: This is a double blind randomized placebo-controlled trial involving 600,700 women with low grade cytological abnormalities on a cervical smear. Randomization is in the ratio of 2 : 1 in favour of active medication. Women with first mildly dyskaryotic smear or second borderline smear are eligible. They are asked to take two capsules daily for 6 months. At the end of 6 months they undergo repeat cervical cytology, HPV testing and colposcopy. Results: A progress report will be given for this ongoing study. [Funded: - Cancer Research UK] Type Specific HPV Infection in Welsh Cervical Cancers Background: Whilst there have been numerous studies of HPV infection associated with cervical cancer and on prevalence of Human Papillomavirus in diverse populations there have been no studies of these variables in the same population. Against a background of prophylactic HPV vaccination it is important to assess potential protection against cervical cancer within a given population. The most comprehensive analysis of HPV type specific cervical cancer is a meta-analysis published by the IARC in 2003. This however included only three UK based studies, totalling 118 cases, 75 of which were only investigated by HPV type PCR for four high risk types. None of this data was presented with associated population based prevalence data. Therefore, the research objectives for this study in combination with the first study above, are as follows: To determine the frequency of specific HPV types in cervical cancers in Wales. To compare the distribution of specific HPV types amongst cervical cancers with their prevalence in the general population. This will allow accurate delineation of the relationship between prevalence of specific HPV types in the general population and their association with clinically relevant disease. This information is a pre-requisite to assess the potential impact of prophylactic vaccination against HPV infection in Wales. Methods: Welsh Cervical Cancer specimens from 2000,2005 will be identified from pathology departments within Wales. The pathology of each tumour will be reviewed by a single Gynaecological Pathologist. The age of the patient and pathological features of the tumour will be noted. DNA will be extracted from the paraffin sections and HPV typed by PCR-EIA. Results: A progress report will be given for this ongoing study. [Funded by Welsh Office for Research and Development] [source]

Mesothelioma Symposium 11.30,12.30 Tuesday 16 September 2003

CYTOPATHOLOGY, Issue 2003
Darrel Whitaker Dr
The diagnosis of malignant mesothelioma on the cytology of serous effusions is a two-phase process. First is to determine that the effusion is malignant based on morphological features such as a highly cellular fluid with many large three dimensional cell aggregates, and/or the recognition of minor malignant criteria including prominent cell engulfment, uniformly present very prominent nucleoli, or the finding of very large (giant) cells. In cell block sections, strong positive staining with EMA often with cell membrane accentuation provides compelling support for a cytological diagnosis of malignancy. Second is to recognize that the malignant cells have a mesothelial phenotype and do not represent metastatic malignancy (usually adenocarcinoma). Criteria in support of mesothelioma include the lack of a ,two cell' population, that is one native (mesothelial) and one foreign (metastatic), cells with abundant dense staining cytoplasm, the presence of ,windows' where mesothelioma cells lie in close apposition and intracytoplasmic glycogen presenting either as small peripheral vacuoles on MGG stained smears or large yellow refractile crescents on Papanicolaou stained smears. In addition, mesothliomas often possess connective tissue stromal cores occurring as either well-formed collagen within papillary aggregates or lying free as pink (MGG) or light green (Pap) amorphous material in the background of the smear or in loose association with mesothelioma cells. Finally small orange staining squamous-like cells can occasionally be identified and sometimes this may be a very prominent finding and has resulted in the false impression of a squamous cell carcinoma. Almost certainly these cells represent apoptotic tumour cells. The connective tissue mucin hyaluronic acid may be found as a net-like pattern in the smear background or as large hard-edged magenta-stained vacuoles on MGG-stained smears. Cell block sections provide architectural information and it is usually possible to separate mesothelioma aggregates with their cuboidal cells, central nuclei and abundant dense cytoplasm arranged in solid, papillary or hollow clusters from those of adenocarcinoma with less dense, often foamy cytoplasm, often composed of columnar cells with elongated nuclei. Aggregate form in adenocarcinoma can be variable but true acini are a rare finding. These cell block sections provide an ideal medium for histochemistry (PAS with and without diastase digestion) and immunocytochemistry. By using a panel of antibodies (Calretinin and CK 5/6, BerEp4, CEA, B72.3) it is almost always possible to distinguish mesothelioma from metastatic adenocarcinoma. Calretinin and CK 5/6 positive staining and absent staining with BerEp4, CEA and B72.3 is considered diagnostic of mesothelioma. [source]

Collagenase-Assisted Fat Dissociation for Autologous Fat Transfer

DERMATOLOGIC SURGERY, Issue 10 2008
DAVID K. MOSCATELLO PHD
BACKGROUND The quality of fat for autologous transfer procedures has been a major focus of research in the past few years. The primary goal of these efforts is to improve the viability and longevity of the graft in human subjects. One possible factor in the permanence of theses transplants is the size of the adipose tissue grafts. OBJECTIVE This study evaluated the effects of collagenase digestion on the viability of human adipose tissue. MATERIALS AND METHODS Samples of fat were obtained from subjects undergoing tumescent liposuction. The tissue was digested in a variety of concentrations of collagenase using optimized methods of processing. The digested fat was also subjected to mock injections through small bore needles. RESULTS Eight subjects completed the study. The viability of the fat using the optimized methods of collagenase digestion was consistently higher than 79%. During the mock injection trials, the viability of fat was improved from approximately 17% to 84% by collagenase digestion. CONCLUSIONS Our results show increased viability of human adipose tissue when digested by collagenase. These techniques can be applied to human autologous lipoaugmentation procedures in an effort to improve longevity of the transplanted tissue. [source]

Epigenetic regulation of the imprinted U2af1-rs1 gene during retinoic acid-induced differentiation of embryonic stem cells

DEVELOPMENT GROWTH & DIFFERENTIATION, Issue 6 2006
Noelia Andollo
Epigenetic modifications such as DNA methylation and changes in chromatin structure are changes in the chemical composition or structure of DNA that work by regulating gene expression. Their mechanisms of action have been generally studied in imprinted genes. The present work analyzes the involvement of these mechanisms in the expression of the U2af1-rs1 imprinted gene during the differentiation process of embryonic stem (ES) cells induced by retinoic acid. By DNA digestion with methylation-dependent or independent restriction enzymes and consecutive Southern blot, we have found that methylation of the U2af1-rs1 gene increases in differentiated ES cells and in embryoid bodies. However, northern blot and real-time reverse transcription,polymerase chain reaction analysis showed a higher expression of the U2af1-rs1 gene in differentiated ES cells and in embryoid bodies than in undifferentiated ones. On the other hand, the sensitivity to DNase-I assay demonstrated an open chromatin conformation for differentiated cells with regard to undifferentiated ES cells. Our results suggest that the expression of the U2af1-rs1 gene would be regulated by changes in chromatin structure rather than by DNA methylation during the RA-induced process of differentiation of ES cells. [source]

Repulsive guidance of axons of spinal sensory neurons in Xenopus laevis embryos: Roles of Contactin and notochord-derived chondroitin sulfate proteoglycans

DEVELOPMENT GROWTH & DIFFERENTIATION, Issue 7 2005
Naoko Fujita
An immunoglobulin superfamily neuronal adhesion molecule, Contactin, has been implicated in axon guidance of spinal sensory neurons in Xenopus embryos. To identify the guidance signaling molecules that Contactin recognizes in tailbud embryos, an in situ binding assay was performed using recombinant Contactin-alkaline phosphatase fusion protein (Contactin-AP) as a probe. In the assay of whole-mount or sectioned embryos, Contactin-AP specifically bound to the notochord and its proximal regions. This binding was completely blocked by either digestion of embryo sections with chondroitinase ABC or pretreatment of Contactin-AP with chondroitin sulfate A. When the spinal cord and the notochord explants were co-cultured in collagen gel, growing Contactin-positive spinal axons were repelled by notochord-derived repulsive activity. This repulsive activity was abolished by the addition of either a monoclonal anti-Contactin antibody, chondroitin sulfate A or chondroitinase ABC to the culture medium. An antibody that recognizes chondroitin sulfate A and C labeled immunohistochemically the notochord in embryo sections and the collagen gel matrix around the cultured notochord explant. Addition of chondroitinase ABC into the culture eliminated the immunoreactivity in the gel matrix. These results suggest that the notochord-derived chondroitin sulfate proteoglycan acts as a repulsive signaling molecule that is recognized by Contactin on spinal sensory axons. [source]

Human primary corneal fibroblasts synthesize and deposit proteoglycans in long-term 3-D cultures

DEVELOPMENTAL DYNAMICS, Issue 10 2008
R. Ren
Abstract Our goal was to develop a 3-D multi-cellular construct using primary human corneal fibroblasts cultured on a disorganized collagen substrate in a scaffold-free environment and to use it to determine the regulation of proteoglycans over an extended period of time (11 weeks). Electron micrographs revealed multi-layered constructs with cells present in between alternating parallel and perpendicular arrays of fibrils. Type I collagen increased 2,4-fold. Stromal proteoglycans including lumican, syndecan4, decorin, biglycan, mimecan, and perlecan were expressed. The presence of glycosaminoglycan chains was demonstrated for a subset of the core proteins (lumican, biglycan, and decorin) using lyase digestion. Cuprolinic blue,stained cultures showed that sulfated proteoglycans were present throughout the construct and most prominent in its mid-region. The size of the Cuprolinic-positive filaments resembled those previously reported in a human corneal stroma. Under the current culture conditions, the cells mimic a development or nonfibrotic repair phenotype. Developmental Dynamics 237:2705,2715, 2008. © 2008 Wiley-Liss, Inc. [source]

Orlistat 120 mg improves glycaemic control in type 2 diabetic patients with or without concurrent weight loss

DIABETES OBESITY & METABOLISM, Issue 4 2009
S. Jacob
Background:, Both obesity and type 2 diabetes are associated with increased morbidity and mortality. Published data suggest that orlistat 120 mg, a lipase inhibitor used to treat obesity, may improve glycaemic parameters through weight loss,independent effects. Aim:, To investigate the effect of orlistat 120 mg on weight loss, and assess whether changes in glycaemic parameters [fasting plasma glucose (FPG) and haemoglobin A1c (HbA1c)] are independent of weight loss. Methods:, This retrospective analysis of pooled data from seven multicentre, double-blind, placebo-controlled studies involved overweight or obese patients with type 2 diabetes (aged 18,70 years). Patients were required to have a body mass index of 27,43 kg/m2, HbA1c of 6.5 to <13%, and stable weight for ,3 months. Subjects received orlistat 120 mg tid or placebo for 6 or 12 months. Results:, A total of 2550 overweight or obese patients with type 2 diabetes were enrolled and randomized to treatment with orlistat 120 mg tid (n = 1279) or placebo (n = 1271). For the whole population, patients treated with orlistat 120 mg had significantly greater mean decreases in FPG compared with placebo-treated patients (,1.39 mmol/l vs. ,0.47 mmol/l; p < 0.0001). In addition, orlistat 120 mg provided significantly larger mean decreases in HbA1c compared with placebo (,0.74% vs. ,0.31%; p < 0.0001). For patients with minimal weight loss (,1% of baseline body weight), orlistat 120 mg still provided a significantly greater decrease in the least squares mean value for both FPG (,0.83 mmol/l vs. ±0.02 mmol/l; p = 0.0052) and HbA1c,0.29% vs. ±0.14%; p = 0.0008). This suggested that the improvement of glycaemic control with orlistat 120 mg was independent of weight loss. Using linear regression analysis, improvement in glycaemic control (FPG and HbA1c) with orlistat 120 mg was less strongly correlated with weight loss than for placebo. Conclusion:, Orlistat 120 mg appears to improve glycaemic control more than would be predicted by weight loss alone in overweight or obese patients with type 2 diabetes. Postulated mechanisms underlying this effect include an improvement of insulin sensitivity, a slower and incomplete digestion of dietary fat, reduction of postprandial plasma non-esterified fatty acids, decreased visceral adipose tissue, and stimulation of glucagon-like peptide-1 secretion in the lower small intestine. [source]

Ghrelin: a new peptide regulating the neurohormonal system, energy homeostasis and glucose metabolism

DIABETES/METABOLISM: RESEARCH AND REVIEWS, Issue 5 2008
Peter Pusztai
Abstract Identification of ghrelin started with the discovery of growth hormone secretagogues, continued with the description of ghrelin receptors and ended with the elucidation of the chemical structure of ghrelin. However, several issues concerning the role of ghrelin in physiological and pathophysiological processes are still under investigation. Most of the ghrelin produced in the body is secreted in the stomach, but it is also expressed in the hypothalamus, pituitary, pancreas, intestine, kidney, heart and gonads. Ghrelin stimulates growth hormone secretion via growth hormone secretagogue receptors. Ghrelin secretion in the stomach depends on both acute and chronic changes in nutritional status and energy balance. Current data support the hypothesis that the stomach, in addition to its important role in digestion, not only influences pituitary hormone secretion but, via ghrelin production, it also sends orexigenic (appetite increasing) signals to hypothalamic nuclei involved in the regulation of energy homeostasis. In addition to these main effects, ghrelin influences insulin secretion and glucose metabolism and it may exert potentially important effects on cardiovascular and gastrointestinal functions. Because of its effects on a large number of physiological functions, ghrelin may be involved in the pathomechanism of several human disorders, including disturbances of appetite, energy homeostasis and glucose metabolism. Further research might lead to a better understanding of the pathophysiology of ghrelin and might provide more effective therapy for the above disorders. Copyright © 2008 John Wiley & Sons, Ltd. [source]

The prevalence of the mitochondrial DNA 16189 variant in non-diabetic Korean adults and its association with higher fasting glucose and body mass index

DIABETIC MEDICINE, Issue 8 2002
J. H. Kim
Abstract Aims To evaluate the prevalence of the 16189 variant of mitochondrial DNA in Korean adults and its association with insulin resistance. Methods We investigated 160 non-diabetic subjects from a community-based diabetes survey conducted in Yonchon County, Korea in 1993. We extracted the DNA from peripheral blood and examined the 16189 variant by polymerase chain reaction and restrictive enzyme digestion. We compared body mass index (BMI), blood pressure, fasting plasma glucose, 2-h plasma glucose after 75 g glucose load, fasting insulin, cholesterol, and homeostasis model assessment of insulin resistance and ,-cell function between the subjects with 16189 variant and wild type. Results The prevalence of the 16189 variant in Korean adults was 28.8% (46 of 160). Subjects with the 16189 variant had higher fasting glucose and BMI than those with wild type, but fasting insulin, homeostasis model assessment of insulin resistance and ,-cell function, cholesterol, and blood pressure were not different between two groups. Conclusion Our results provide evidence for an association of a frequent mitochondrial polymorphism with higher fasting glucose and the risk factors of diabetes mellitus. [source]

Ultrastructure and functional features of midgut of an adult water mite Teutonia cometes (Koch, 1837) (Hydrachnidia: Teutoniidae)

ACTA ZOOLOGICA, Issue 2 2010
Andrew B. Shatrov
Abstract Shatrov, A. B. 2010. Ultrastructure and functional features of midgut of an adult water mite Teutonia cometes (Koch 1837) (Hydrachnidia: Teutoniidae). ,Acta Zoologica (Stockholm) 91: 222,232 The midgut of the adult water mite Teutonia cometes (Koch 1837) (Hydrachnidia: Teutoniidae) was investigated by means of transmission electron microscopy and on semi-thin sections. The midgut is represented by a blind sac composed of the narrow ventriculus, two proventricular lateral diverticula and three pairs of postventricular caeca. A single-layered epithelium consists of one type of endodermal digestive cells of quite different shape and size, which may form protrusions into the midgut lumen. The large nuclei are frequently lobed and contain one to three nucleoli. The apical cell membrane forms short scarce microvilli, between their bases the pinocytotic vesicles of unspecific macropinocytosis as well as the narrow pinocytotic canals are formed and immersed into the cell. The intracellular digestion of the food ingested into the midgut after extraintestinal digestion is predominant. The pinocytotic vesicles fuse with small clear vesicles of proposed Golgi origin to form secondary lysosomes. The digestive cells also contain small amounts of rough endoplasmic reticulum, variously structured heterolysosomes, residual materials in the form of both the small electron-dense bodies and the large variously granulated substances, reserve nutritive materials such as lipid and glycogen, as well as clear vacuoles. Residual materials are obviously extruded from the cells into the gut lumen. [source]

Recombinant clotting factor VIII concentrates: Heterogeneity and high-purity evaluation

ELECTROPHORESIS, Issue 16 2010
Gian Maria D'Amici
Abstract Factor VIII is an important glycoprotein involved in hemostasis. Insertion of expression vectors containing either the full-length cDNA sequence of human factor VIII (FLrFVIII) or B-domain deleted (BDDrFVIII) into mammalian cell lines results in the production of recombinant factor VIII (rFVIII) for therapeutic usage. Three commercially available rFVIII concentrates (Advate®, Helixate NexGen® and Refacto®), either FLrFVIII or BDDrFVIII, were investigated by 1- and 2-DE and MS. The objective of this study was to compare the heterogeneity and the high purity of both rFVIII preparations before and after thrombin digestion. In particular, the 2-D gel was optimized to better highlight the presence of contaminants and many unexpected proteins. Recombinant strategies consisting of insertion of expression vectors containing BDDrFVIII and FLrFVIII resulted in homogeneous and heterogeneous protein products, respectively, the latter consisting in a heterogeneous mixture of various B-domain-truncated forms of the molecule. Thrombin digestion of all the three rFVIII gave similar final products, plus one unexpected fragment of A2 domain missing 11 amino acids. Regarding the contaminants, Helixate NexGen® showed the presence of impurities, such as Hsp70,kDa, haptoglobin and proapolipoprotein; Refacto® showed glutathione S -transferase and ,-lactamase, whereas Advate® apparently did not contain any contaminants. The proteomic approach will contribute to improving the quality assurance and manufacturing processes of rFVIII concentrates. In this view, the 2-DE is mandatory for revealing the presence of contaminants. [source]

Analysis of integral membrane proteins by heat gel-embedment combined with improved in-gel digestions

ELECTROPHORESIS, Issue 23 2009
Jian Zhou
Abstract Analysis of integral membrane proteins (IMPs) presents a special challenge because of their hydrophobic nature and low abundance. Here, a new method was developed, which involved heat gel-embedment and improved in-gel digestion of the proteins. Membrane protein lysate containing detergents was mixed with acrylamide solution and the proteins were embedded when the gel polymerized. For comparison, the protein embedment was made at different temperatures (25, 35 or 45°C), and the in-gel digestions were performed in the presence of 0.1% RapiGest reagent (ALS), 0.1% sodium deoxycholate and 10% ACN, respectively. The resultant peptides were extracted and analyzed by capillary liquid chromatography coupled with tandem mass spectrometry. Compared with that at 25°C, gel-embedment at 45°C improved the protein embedment and thus protein identification, with the identified IMPs increased by 27%. 0.1% sodium deoxycholate was more efficient than 0.1% ALS and 10% ACN in terms of improving the digestion and tryptic digest recovery of the gel-embedded proteins particularly the hydrophobic IMPs. Out of the 326 IMPs identified by heat gel-embedment combined with improved in-gel digestion strategies, 149 (46%) proteins had at least two mapped transmembrane domains. These results indicate that our newly developed protocol could facilitate the high throughput analysis of integral membrane proteome. [source]

Cover Picture: Electrophoresis 6'09

ELECTROPHORESIS, Issue 6 2009
Article first published online: 23 MAR 200
Issue no. 6 is an Emphasis Issue with 7 articles on various aspects of "Proteins and Proteomics" while the remaining 15 articles are arranged into 4 different parts on "Genotyping and Sequencing", "Enantioseparations", "Non Aqueous CE", and "Methodologies and Applications." Selected articles are: Differences in protein distribution between human plasma preparations, EDTA-plasma and heparin-plasma, analyzed by non-denaturing micro-2-DE and MALDI-MS PMF 2-DE and MS analysis of key proteins in the adhesion of Lactobacillus plantarum, a first step toward early selection of probiotics based on bacterial biomarkers Centrifugal methods and devices for rapid in-gel digestion of proteins [source]

Identification of CpG methylation of the SNRPN gene by methylation-specific multiplex PCR

ELECTROPHORESIS, Issue 2 2009
Chia-Cheng Hung
Abstract In this article, we show that methylation-specific multiplex PCR (MS-multiplex PCR) is a sensitive and specific single assay for detecting CpG methylation status as well as copy number aberrations. We used MS-multiplex PCR to simultaneously amplify three sequences: the 3, ends of the SNRPN gene (for unmethylated sequences), the KRITI gene (as internal control), and the promoter of the SNRPN gene containing CpG islands (for methylated sequences) after digestion with a methylation-sensitive restriction enzyme (HhaI). We established this duplex assay for the analysis of 38 individuals with Prader,Willi syndrome, 2 individuals with Angelman syndrome, and 28 unaffected individuals. By comparing the copy number of the three regions, the methylation status and the copy number changes can be easily distinguished by MS-multiplex PCR without the need of bisulfite treatment of the DNA. The data showed that MS-multiplex PCR allows for the estimation of the methylation level by comparing the copy number aberrations of unknown samples to the standards with a known methylated status. The in-house-designed MS-multiplex PCR protocol is a relatively simple, cost-effective, and highly reproducible approach as a significant strategy in clinical applications for epigenetics in a routine laboratory. [source]

The resistance of metallothionein to proteolytic digestion: An LC-MS/MS analysis

ELECTROPHORESIS, Issue 16 2007
Rongying Wang
Abstract Metallothioneins (MTs) are a family of cysteine-rich metalloproteins which strongly bind to heavy metals, such as Cd(II), Zn(II), and Cu(I). Previous works by other group using gel electrophoresis and fluorescence showed MTs were resistant to proteolytic digestion by a variety of enzymes, raising the difficulties in proteomic identification of MTs. The present work was attempted to analyze the resistance of MTs to trypsin using LC with MS/MS (LC-MS/MS), which was able to determine the sequences of the produced peptides and thus precisely characterize the cleavages. The results showed that metal-saturated MTs were completely resistant to trypsin. This resistance problem could be overcome by the addition of EDTA to MT samples, which rendered MTs readily digested into peptides and identified by MS/MS. Interestingly, the partially metal binding MTs were digested into peptides predominantly with miss cleavages which were well dependent on the amount of heavy metals bound to MTs. An explanation for these observations was proposed. The potential applications of the MT's resistance to trypsin in isolation and identification of MTs in complex mixtures such as cultured cells was demonstrated. The preliminary data also showed the same proteomic approach of proteolytic digestion followed by MS/MS analysis may provide information on metal binding status of MTs, along with the identification of MTs in a mixture. [source]

High MS-compatibility of silver nitrate-stained protein spots from 2-DE gels using ZipPlates and AnchorChips for successful protein identification

ELECTROPHORESIS, Issue 10 2007
Grit Nebrich
Abstract The availability of easy-to-handle, sensitive, and cost-effective protein staining protocols for 2-DE, in conjunction with a high compatibility for subsequent MS analysis, is still a prerequisite for successful proteome research. In this article we describe a quick and easy-to-use methodological protocol based on sensitive, homogeneous, and MS-compatible silver nitrate protein staining, in combination with an in-gel digestion, employing the Millipore 96-well ZipPlate system for peptide preparation. The improved quality and MS compatibility of the generated protein digests, as compared to the otherwise weakly MS-compatible silver nitrate staining, were evaluated on real tissue samples by analyzing 192 Coomassie-stained protein spots against their counterparts from a silver-stained 2-DE gel. Furthermore, the applicability of the experimental setup was evaluated and demonstrated by the analysis of a large-scale MALDI-TOF MS experiment, in which we analyzed an additional ,1000 protein spots from 2-DE gels from mouse liver and mouse brain tissue. [source]