Current Protocols (current + protocol)

Distribution by Scientific Domains


Selected Abstracts


Detection of cryptosporidia and Cryptosporidium parvum oocysts in environmental water samples by immunomagnetic separation,polymerase chain reaction

JOURNAL OF APPLIED MICROBIOLOGY, Issue 1 2000
S. Hallier-Soulier
Cryptosporidium parvum has emerged as one of the most important new contaminants found in drinking water. Current protocols for the detection of cryptosporidia are time-consuming and rather inefficient. We recently described an immunomagnetic separation,polymerase chain reaction (IMS,PCR) assay permitting highly sensitive detection of C. parvum oocysts in drinking water samples. In this study, a second IMS,PCR assay to detect all cryptosporidial oocysts was developed, and both IMS,PCR assays were optimized on river water samples. A comparative study of the two IMS,PCR assays and the classical detection method based on an immunofluorescence assay (IFA) was carried out on 50 environmental samples. Whatever the type of water sample, the discrepancy in C. parvum detection between the IFA and IMS,PCR took the form of IFA-negative/IMS,PCR-positive results, and was caused mainly by the greater sensitivity of IMS,PCR as compared with IFA. Of the 50 water samples, only five tested positive for C. parvum using IMS,PCR, and could constitute a threat to human health. These results show that both IMS,PCR assays provide a rapid (1 d) and sensitive means of screening environmental water samples for the presence of cryptosporidia and C. parvum oocysts. [source]


Multiple myeloma patients receiving large volume leukapheresis efficiently yield enough CD34+ cells to allow double transplants

JOURNAL OF CLINICAL APHERESIS, Issue 1 2009
A.C. Zubair
Abstract Current protocols for myeloma patients require more than one autologous transplant. We performed a retrospective study to determine the cost-effectiveness of large volume leukapheresis (LVL) compared with standard volume leukapheresis (SVL) collection when two transplants are required. We evaluated 87 patients who underwent a cumulative total of 260 LVL and SVL collections. The median product volume per collection was 356 ml for LVL, and this was significantly higher than the median product volume per collection for SVL (median 149.5 ml, P < 0.001). The median total CD34+ cell yield/kg was 6.4 × 106 for LVL and 5.2 × 106 for SVL. This difference was statistically significant (P = 0.005). Because the target CD34+ cell dose for a single transplant was 3 × 106/kg at our institution, overall the LVL yields enough CD34+ cells that could allow for two transplants. Therefore, more patients in the LVL group were able to undergo a potential second transplant. Because of the reserved cells for a second transplant, LVL patients received significantly less CD34+ cell/kg per transplant than the patients in SVL group (P = <0.001). As a result, LVL group had statistically significant but clinically insignificant delay in neutrophil (P = <0.001) and platelet (P = 0.02) engraftments. Additionally, using LVL instead of SVL to collect ,6 × 106/kg CD34+ cells may potentially save $7,497 per patient. We therefore conclude that LVL is the method of choice for collection of multiple myeloma patients when two transplants are anticipated. J. Clin. Apheresis, 2009. © 2009 Wiley-Liss, Inc. [source]


INDETERMINATE RESULTS IN CORE BIOPSIES OF BREAST FROM MAMMOGRAPHICALLY DETECTED LESIONS: OUTCOMES OF EXCISION BIOPSY

PATHOLOGY INTERNATIONAL, Issue 12 2001
Harvey J
INTRODUCTION: Protocols for excision of mammographically detected lesions following core biopsy include all diagnoses of atypical ductal hyperplasia (ADH) or intraductal atypia of uncertain significance (AUS). The aims of this study were to look at: i) the prevalence of reporting ADH and AUS, ii) the proportion of cases where excision revealed breast carcinoma, iii) whether any cases could be downgraded to hyperplasia on review. METHODS: Breast core biopsy reports from the SCGH Breast Centre for the years 1999,2000 were retrieved. The results of excision biopsy were obtained and slides reviewed. RESULTS: There were 1048 core biopsies from 911 women. Breast carcinoma was diagnosed in 197 samples (18.8%) including 88 with invasive carcinoma (8.4%), 109 with ductal carcinoma in situ (10.4%) and 3 samples (2.9%) suspicious of invasive carcinoma. The suspicious cases all proved to be invasive carcinomas. There were 53 samples (5.1%) with a diagnosis of ADH or AUS. 46 were excised, showing 7 invasive carcinomas 15 DCIS, 11 ADH, 2 lobular carcinoma in situ (LCIS), 1 mucocoele-like lesion, 1 fibroadenoma and 9 fibrocystic change (FCC). The 22 malignancies represented 47.8% of the excised lesions. At review, 8 of the 53 original diagnoses were downgraded to benign hyperplasia; 5 underwent excision; 2 showed ,incidental' invasive carcinomas, 1 ,incidental' LCIS, 1 ADH and 1 FCC. CONCLUSIONS: There was a low prevalence of reporting of ADH and AUS in core biopsies (5.1%) and a high rate of carcinoma (47.8%) in subsequent excision biopsies. Very few diagnoses of ADH/AUS were downgraded at review. Current protocols for excision of lesions with a core biopsy diagnosis of ADH/AUS appear to be justified. [source]


A robust bulk-solvent correction and anisotropic scaling procedure

ACTA CRYSTALLOGRAPHICA SECTION D, Issue 7 2005
Pavel V. Afonine
A reliable method for the determination of bulk-solvent model parameters and an overall anisotropic scale factor is of increasing importance as structure determination becomes more automated. Current protocols require the manual inspection of refinement results in order to detect errors in the calculation of these parameters. Here, a robust method for determining bulk-solvent and anisotropic scaling parameters in macromolecular refinement is described. The implementation of a maximum-likelihood target function for determining the same parameters is also discussed. The formulas and corresponding derivatives of the likelihood function with respect to the solvent parameters and the components of anisotropic scale matrix are presented. These algorithms are implemented in the CCTBX bulk-solvent correction and scaling module. [source]


Subcutaneous administration of hepatitis B immune globulin in combination with lamivudine following orthotopic liver transplantation: effective prophylaxis against recurrence

CLINICAL TRANSPLANTATION, Issue 4 2006
James J. Powell
Abstract:, Prophylaxis against recurrent hepatitis B virus (HBV) infection with hepatitis B immune globulin (HBIG), in combination with antiviral agents such as lamivudine, has allowed transplantation for this condition to become feasible and accepted. Current protocols allow for HBIG administration either intravenously or intramuscularly. To date, there has been no reported experience with the subcutaneous route of post-transplant HBIG delivery. We report our experience of a 60-yr-old man for whom liver transplantation was performed for chronic HBV. HBIG was administered intramuscularly during the anhepatic phase of surgery. The finding of a portal vein thrombosis requiring repeated thrombectomy necessitated chronic anticoagulation. Post-operatively, HBIG was administered subcutaneously, in four separate injections, for a daily dose of 2170 IU along with continued lamivudine dosing. Hepatitis B surface antibody (anti-HBs) titres reached a serum concentration of >500 IU/L by seven d post-transplant and approximately 1000 IU/L by nine d post-transplant. Five months post-transplant, with continued combination of subcutaneous HBIG and lamivudine, there has been no recurrent HBV infection and anti-HBs titres have been at target levels. Our experience suggests that subcutaneous delivery of HBIG may be a feasible consideration when intramuscular/intravenous dosing is not possible. [source]


The role of stem cells in suppurative environments

EXPERIMENTAL DERMATOLOGY, Issue 6 2006
Dolores Herreros
Purpose:,The management of suppurative perianal lesions presents an extremely challenging problem. Stem cells (SC) extracted from certain tissues, such as adipose tissue, can differentiate into various cell types. Therefore, we have tried to use such cells to stimulate healing in a purulent environment. Methods:,In the beginning, we designed a phase I clinical trial, involving five patients with Crohn's disease. We inoculated nine fistulas in four patients with autologous adipose-derived stem cells (ADSC) and were followed at least 8 weeks. Seventy-five percent became healed, and 25% showed a decrease in output flow. No adverse effects were observed in any patient. This study evidenced that such cells are safe. Then, we started a research line using SC in different suppurative environments. During the course of these studies, we had the opportunity to treat a patient with perianal hidradenitis suppurativa using our current protocol of ADSC transplantation. Eight weeks after injection, patient had no perianal suppuration, and a year later remains well. Discussion:,The biological mechanism that underlies the therapeutic success of ADSC transplantation is unknown. Cell differentiation, secretion of growth factors or immunomodulatory effects have been suggested. No ethical conflicts were identified by our Ethics Committee, because the cells were autologous. Conclusions:,Our study shows that ADSC are safe for the treatment of suppurative processes. The actual number of patients included and the uncontrolled nature of these pilot studies do not allow demonstration of the effectiveness of the treatment. However, the results encourage the performance of further studies. [source]


Pulp revascularization of necrotic bilateral bicuspids using a modified novel technique to eliminate potential coronal discolouration: a case report

INTERNATIONAL ENDODONTIC JOURNAL, Issue 1 2009
K. Reynolds
Abstract Aim, To present a case report in which the pulp of two bilateral mandibular premolars with dens evaginatus were revascularized using a modified novel technique to avoid undesired crown discolouration. Summary, Recently, regeneration of necrotic pulps has become an alternative conservative treatment option for young permanent teeth with immature roots and is a subject of great interest in the field of endodontics. This novel procedure exploits the full potential of the pulp for dentine deposition and produces a stronger mature root that is better able to withstand the forces than can result in fracture. However, the current protocol has potential clinical and biological complications. Amongst them, crown discolouration, development of resistant bacterial strains and allergic reaction to the intracanal medication. In the case presented, a modified technique to avoid undesired crown discolouration was applied sealing the dentinal tubules of the chamber, thus avoiding any contact between the tri-antibiotic paste and the dentinal walls. Key learning points, ,,Sealing the dentinal tubules of the chamber prevents the undesirable crown discolouration produced by tri-antibiotic medication whilst maintaining the revascularization potential of the pulp. ,,Further research is warranted to seek an alternative infection control protocol capable of preventing possible allergic reactions and development of resistant strains of bacteria, as well as a biological material capable of inducing angiogenesis and allow a more predictable scaffold and tissue regeneration. [source]


In vivo quantification of regional myocardial blood flow: Validity of the fast-exchange approximation for intravascular T1 contrast agent and long inversion time,

MAGNETIC RESONANCE IN MEDICINE, Issue 2 2006
Marlene Wiart
Abstract In the present study we investigated the effects of water exchange between intra- and extravascular compartments on absolute quantification of regional myocardial blood flow (rMBF) using a saturation-recovery sequence with a rather long inversion time (TI, 176 ms) and a T1 -shortening intravascular contrast agent (CMD-A2-Gd-DOTA). Data were acquired in normal and ischemically injured pigs, with radiolabeled microsphere flow measurements used as the gold standard. Five water exchange rates (fast, 6 Hz, 3 Hz, 1 Hz, and no exchange) were tested. The results demonstrate that the fast-exchange approximation may be appropriate for rMBF quantification using the described experimental setting. Relaxation rate change (,R1) analysis improved the accuracy of the analysis of rMBF compared to the MR signal. In conclusion, the current protocol could provide sufficient accuracy for estimating rMBF assuming fast exchange and a linear relationship between signal and tissue concentration when quantification of precontrast T1 is not an option. Magn Reson Med, 2006. © 2006 Wiley-Liss, Inc. [source]


Intratympanic Dexamethasone for Sudden Sensorineural Hearing Loss After Failure of Systemic Therapy

THE LARYNGOSCOPE, Issue 1 2007
David S. Haynes MD
Abstract Objective: Intratympanic steroids are increasingly used in the treatment of inner ear disorders, especially in patients with sudden sensorineural hearing loss (SNHL) who have failed systemic therapy. We reviewed our experience with intratympanic steroids in the treatment of patients with sudden SNHL to determine overall success, morbidity, and prognostic factors. Hypothesis: Intratympanic steroids have minimal morbidity and the potential to have a positive effect on hearing recovery in patients with sudden SNHL who have failed systemic therapy. Study Design: The authors conducted a retrospective review. Methods: Patients presenting with sudden SNHL defined as a rapid decline in hearing over 3 days or less affecting 3 or more frequencies by 30 dB or greater who underwent intratympanic steroids therapy (24 mg/mL dexamethasone) were reviewed. Excluded were patients with Meniere disease, retrocochlear disease, autoimmune HL, trauma, fluctuating HL, radiation-induced HL, noise-induced HL, or any other identifiable etiology for sudden HL. Patients who showed signs of fluctuation of hearing after injection were excluded. Pretreatment and posttreatment audiometric evaluations including pure-tone average (PTA) and speech reception threshold (SRT) were analyzed. Patient variables as they related to recovery were studied and included patient age, time to onset of therapy, status of the contralateral ear, presence of diabetes, severity of HL, and presence of associated symptoms (tinnitus, vertigo). A 20-dB gain in PTA or a 20% improvement in SDS was considered significant. Results: Forty patients fit the criteria for inclusion in the study. The mean age of the patients was 54.8 years with a range from 17 to 84 years of age. Overall, 40% (n = 16) showed any improvement in PTA or SDS. Fourteen (35%) men and 26 (65%) women were included. Using the criteria of 20-dB improvement in PTA or 20% improvement in SDS for success, 27.5% (n = 11) showed improvement. The mean number of days from onset of symptoms to intratympanic therapy was 40 days with a range of 7 days to 310 days. A statistically significant difference was noted in those patients who received earlier injection (P = .0008, rank sum test). No patient receiving intratympanic dexamethasone after 36 days recovered hearing using 20-dB PTA decrease or a 20% increase in discrimination as criteria for recovery. Twelve percent (n = 5) of patients in the study had diabetes with 20% recovering after intratympanic dexamethasone (not significantly different from nondiabetics at 28.6%, Fisher exact test, P = 1.0). Comparison to other studies that used differing steroid type, concentration, dosing schedule, inclusion criteria, and criteria for success revealed, in many instances, a similar overall recovery rate. Conclusions: Difficulty in proving efficacy of a single modality is present in all studies on SNHL secondary to multiple treatment protocols, variable rates of recovery, and a high rate of spontaneous recovery. Forty percent of patients showed some improvement in SDS or PTA after treatment failure. When criteria of 20-dB PTA or 20% is considered to define improvement, the recovery rate was 27.5%. Modest improvement is seen with the current protocol of a single intratympanic steroid injection of 24 mg/mL dexamethasone in patients who failed systemic therapy. Dramatic hearing recovery in treatment failures was rarely encountered. No patient showed significant benefit from intratympanic steroids after 36 days when using this protocol for idiopathic sudden SNHL. If patients injected after 6 weeks are excluded from the study, the improvement rate increases from 26.9% to 39.3%. Earlier intratympanic injection had a significant impact on hearing recovery, although with any therapeutic intervention for sudden SNHL, early success may be attributed to natural history. If we further exclude seven patients treated with intratympanic steroids within 2 weeks of the onset of symptoms (i.e., study only those patients treated with intratympanic dexamethasone between 2 and 6 weeks after onset of symptoms), still, 26% improved by 20 dB or 20% SDS. The recovery rates after initial systemic failure are higher than would be expected in this treatment failure group given our control group (9.1%) and literature review. These findings indicate a positive effect from steroid perfusion in this patient population. [source]


Postoperative monitoring of free flaps in UK plastic surgery units

MICROSURGERY, Issue 6 2005
Ch.B. (Hons.), M.R.C.S. (Eng.), N. Jallali B.Sc.
Monitoring free-tissue transfers in the postoperative period is valuable for detection of failing flaps. As well as conventional methods, a myriad of sophisticated techniques have been reported in the literature. Using a postal questionnaire, a survey was conducted to delineate current protocols employed in UK plastic surgery units. Data were received from 148 plastic surgeons in 51 units. All surgeons used clinical assessment, although there was significant disparity in the duration and frequency of postoperative monitoring. Adjuvant techniques such as laser Doppler flowmetry were routinely used by less than 20% of surgeons. We conclude that there is considerable variation in postoperative monitoring of free flaps, with significant clinical and resource implications. A protocol based on robust evidence is thus recommended. © 2005 Wiley-Liss, Inc. Microsurgery 25:469,472, 2005. [source]


Baseline Donor-Specific Antibody Levels and Outcomes in Positive Crossmatch Kidney Transplantation

AMERICAN JOURNAL OF TRANSPLANTATION, Issue 3 2010
J. M. Gloor
Renal transplant candidates with donor-specific alloantibody (DSA) have increased risk of antibody-mediated allograft injury. The goal of this study was to correlate the risk of antibody-mediated rejection (AMR), transplant glomerulopathy (TG) and graft survival with the baseline DSA level (prior to initiation of pretransplant conditioning). These analyses include 119 positive crossmatch (+XM) compared to 70 negative crossmatch (,XM) transplants performed between April 2000 and July 2007. Using a combination of cell-based crossmatch tests, DSA level was stratified into very high +XM, high +XM, low +XM and ,XM groups. In +XM transplants, increasing DSA level was associated with increased risk for AMR (HR = 1.76 [1.51, 2.07], p = 0.0001) but not TG (p = 0.18). We found an increased risk for both early and late allograft loss associated with very high DSA (HR = 7.71 [2.95, 20.1], p = 0.0001). Although lower DSA recipients commonly developed AMR and TG, allograft survival was similar to that of ,XM patients (p = 0.31). We conclude that the baseline DSA level correlates with risk of early and late alloantibody-mediated allograft injury. With current protocols, very high baseline DSA patients have high rates of AMR and poor long-term allograft survival highlighting the need for improved therapy for these candidates. [source]


Peritoneal Cooling May Provide Improved Protection for Uncontrolled Donors After Cardiac Death: An Exploratory Porcine Study

AMERICAN JOURNAL OF TRANSPLANTATION, Issue 6 2009
A. P. Navarro
Uncontrolled donation after cardiac death (DCD) renal transplantation relies on rapid establishment of organ preservation interventions. We have developed a model of the uncontrolled DCD, comparing current in situ perfusion (ISP) techniques with additional peritoneal cooling (PC). Ten pigs were killed and subjected to a 2 h ischemia period. The ISP group modeled current DCD protocols. The PC group (PC) modeled current protocols plus PC. Two animals were used as controls and subjected to 2 h of warm ischemia. Core renal temperature and microdialysis markers of ischemia were measured. Preservation interventions began at 30 min, with rapid laparotomy and kidney recovery performed at 2 h, prior to machine perfusion viability testing. The final mean renal temperature achieved in the ISP group was 26.3°C versus 16.9°C in the PC group (p = 0.0001). A significant cryopreservation benefit was suggested by lower peak microdialysate lactate and glycerol levels (ISP vs. PC, p = 0.0003 and 0.0008), and the superiority of the PC group viability criteria (p = 0.0147). This pilot study has demonstrated significant temperature, ischemia protection and viability assessment benefits with the use of supplementary PC. The data suggests a need for further research to determine the potential for reductions in the rates of ischemia-related clinical phenomena for uncontrolled DCDs. [source]