Blood Supply (blood + supply)

Distribution by Scientific Domains
Distribution within Medical Sciences

Selected Abstracts

Blood Supply in the Tongue of Nellore Bos indicus (Linnaeus, 1758)

J. R. Ferreira
Summary Aspects of the vascularization of the tongue of Nellore Bos indicus (Linnaeus, 1758) were evaluated through the vascular injection technique (with latex-type Neoprene 450, Du Pont do Brasil S.A. and Sulvinil coloring, Glassurit), fixed in formaldehyde at 7% and dissected with magnifying glass. The material was collected at Goiás Carnes Freezer Warehouse in Goiania, Goias. It was found that the deep lingual artery penetrated the lower lateral region of the prominence of the dorsal area of the tongue, advancing rostrally between the hyoid bone and the hypoglossal muscle. In the intravisceral initial third, the artery represents the deep, sinuous continuation branch of the lingual artery, in which path the sublingual artery was stressed in the ventral plan. Then, the artery deepened in the interior of the hypoglossal muscles and genioglossal, supplying dorsal branches (from three to nine) for the lingual torus; from one to five dorsal collateral branches for the lingual cavity; and one or two ventral collateral branches. At the lingual apex, the artery undergoes bifurcation supplying collateral, dorsal and ventral branches with anastomoses between the parallel vessels in the same antimere and between branches of lower caliber hierarchy between opposite antemeres. The large presence of microvessels indicates a significant blood supply to the organ. These results, in comparison with those found in literature, suggest a peculiar vascular pattern for this cattle breed of Indian origin. [source]

Left Ventricular Non Compaction in Children

Sara H. Weisz MD
ABSTRACT Left ventricular non compaction (LVNC) is a myocardial disease characterized by a hypertrabeculated myocardium. The hypertrabeculations in the left ventricular wall define deep recesses communicating with the left ventricular chamber where blood penetrates with increased risk of blood clots in the meshwork of the prominent trabeculations. The left ventricular apex and the free wall are particularly affected. During in utero ventriculogenesis, myocardial blood supply is initially linked to the presence of sinusoids, in which blood penetrates and diffuses nutriments and oxygen to myocardial cells. Progressively, with the development of the heart and the increase of cells demand of blood, coronary arteries system develops. This step is associated with myocardial modification that leads to compaction of hypertrabeculated myocardial net. Probably, the premature interruption of this process leads to ventricular noncompaction. Many studies have been conducted in adults with hypertrabeculated myocardium. To date, data regarding childhood LVNC are sparse. The aim of this review is to summarize the clinical and preclinical knowledge about LVNC in children. [source]

Advancement Flaps: A Basic Theme with Many Variations

Ravi Krishnan MD
Background. The advancement flap involves the linear advancement of tissue in one direction. Despite its straightforwardness and simple concept, it can be used to close a variety of defects, ranging from small defects on the scalp or extremities to large, complicated defects involving cosmetic units on the face. Objectives. To provide a basic and useful review for the indications, advantages, disadvantages, and techniques for the use of advancement flaps in the reconstruction of defects in dermatologic surgery. Materials and Methods. We performed a literature search for articles discussing advancement flaps and compiled a brief review of our findings. Results. The movement of the advancement flap must be balanced by the blood supply of the flap. The excision of Burow's triangles along various aspects of the advancement flap can increase movement and improve cosmesis of the flap. The types of advancement flaps discussed include the single advancement flap, double advancement flap, A-T flap (O-T flap), Burow's triangle flap (Burow's wedge flap), crescenteric advancement flap, island pedicle flap (V-Y flap), helical rim advancement flap, and facelift flap. Conclusion. Advancement flaps are versatile and useful basic flaps for repairing defects. [source]

The Versatility of the Nasolabial Flap Enhanced by the Delay Procedure

Isaac Zilinsky MD
Background. The nasolabial flap is a versatile and effective option for the closure of nasal defects of the cheek and nasal sidewall following Mohs surgery. However, both extirpation of a tumor in the region of the base of the flap or previous use of the flap often destroy the proximal axial blood supply to the flap, excluding its immediate utilization. We describe a different use of the nasolabial flap and a technique for preserving its capacity in the case of reutilization Objective. To describe the versatility of the nasolabial flap and a delay procedure that enables its exploitation despite prior disruption of the proximal blood supply. Methods. Three different uses of the same nasolabial flap are demonstrated in one patient. The surgical techniques are discussed in detail. Results. The reconstructive results were excellent. There were no postoperative complications. Conclusion. The nasolabial flap is a versatile and effective option for the closure of nasal defects of the cheek and nasal sidewall. When the nasolabial flap has been used before, or its blood supply compromised, the delay procedure can reestablish its applicability. [source]

Some historical aspects of diabetic foot disease

Henry Connor
Abstract During the 19th century and for much of the 20th century, disease of the lower limb in diabetic patients was conceptualized not, as it is now, as ,the diabetic foot' or as ,a diabetic foot ulcer' but as ,gangrene in the diabetic foot' or as ,diabetic gangrene'. The prognostically and therapeutically important distinction between gangrene due to vascular insufficiency and gangrene due to infection in a limb with a normal or near normal blood supply was not made until about 1893. The advent of aseptic surgery improved the survival of amputation flaps, but surgery remained a hazardous undertaking until the discovery of insulin. Although insulin therapy reduced the risk of surgical intervention, diabetic foot disease now replaced hyperglycaemic coma as the major cause of diabetic mortality. The increasing workload attributable to diabetic foot disease after the introduction of insulin is reflected in the publications on diabetes in the 1920s. In some hospitals in North America this led to initiatives in prophylactic care and patient education, the importance of which were only more widely appreciated some 60 years later. A continuing emphasis on ischemia and infection as the major causes of diabetic foot disease led to a neglect of the role of neuropathy. In consequence, the management of diabetic neuropathic ulceration entered a prolonged period of therapeutic stagnation at a time when significant advances were being made in the management of lepromatous neuropathic ulceration. Reasons for the revival of progress in the management of diabetic neuropathic ulceration in the 1980s will be discussed. Copyright © 2008 John Wiley & Sons, Ltd. [source]

TBI or not TBI: that is the question.

Is it better to measure toe pressure than ankle pressure in diabetic patients?
Abstract Aims Measurement of ankle blood pressure is a simple method of assessing lower limb arterial blood supply. However, its use in diabetes has been questioned due to the presence of medial artery calcification. Measurement of toe blood pressure has been advocated as an alternative but it is technically more difficult. The aim of this study was to obtain information to guide clinicians as to when pressure measurements should be taken at the toe. Methods Ankle brachial index (ABI) and toe brachial index (TBI) were measured by Doppler ultrasound, or photoplethysmography on 174 subjects with diabetes and 53 control subjects. The Bland and Altman method, and the Cohen's method of measuring agreement between two tests were used to compare ABI with TBI. Results The mean differences between ABI and TBI in control and diabetic subjects are 0.40 ± 0.13 and 0.37 ± 0.15, respectively. Nearly all diabetic patients with an ABI <,1.3 have an ABI,TBI gradient falling within the normal range established from the non-diabetic cohort. In contrast, the majority of diabetic subjects with an ABI ,,1.3 have ABI,TBI differences outside this range. When patients are categorized according to ABI and TBI, there is also good agreement between the tests when ABI is low or normal (84% and 78% agreement, respectively), but not when ABI is elevated. Conclusion In the majority of patients with diabetes, assessment of TBI conveys no advantage over ABI in determining perfusion pressure of the lower limbs. Only in those patients with overt calcification, which gives an ABI ,,1.3, are toe pressure measurements superior. This guideline should simplify assessment and treatment of diabetic patients with disease of the lower limbs. Diabet. Med. 18, 528,532 (2001) [source]

Recurrence of intramucosal esophageal adenocarcinoma arising in a former esophagostomy site: a unique case report

J. M. Leers
SUMMARY., A 75-year-old male with a long history of gastroesophageal reflux symptoms developed adenocarcinoma proximally within a long segment of Barrett's esophagus. He was taken for esophagectomy and gastric pull-up, but intraoperatively, he was found to have a marginal blood supply in the gastric tube. A temporary left-sided esophagostomy was created with the gastric tube sutured to the left sternocleidomastoid muscle in the neck. Pathology showed an intramucosal adenocarcinoma, limited to the muscularis mucosa with surrounding high-grade dysplasia and intestinal metaplasia. The proximal esophageal margin showed no tumor cells, but there was low-grade dysplasia within Barrett's esophagus. He was reconstructed after several months, and 2 years after reconstruction, the patient noticed a nodule at the former esophagostomy site. Biopsy revealed an implant metastasis of esophageal adenocarcinoma. Here, we review the literature and discuss the possible etiology. [source]

Colon interposition in the treatment of esophageal caustic strictures: 40 years of experience

J. Đ. Knez
SUMMARY., The objective of this article was to analyze 40 years of experience of colon interposition in the surgical treatment of caustic esophageal strictures from the standpoints of our long-term personal experience. Colon interposition has proved to be the most suitable type of reconstruction for esophageal corrosive strictures. The choice of colon graft is based on the pattern of blood supply, while the type of anastomosis is determined by the stricture level and the part of colon used for reconstruction. In the period between 1964 and 2004, colon interposition was performed in 336 patients with a corrosively scared esophagus, using the left colon in 76.78% of the patients. In 87.5% a colon interposition was performed, while in the remaining patients an additional esophagectomy with colon interposition had to be done. Hypopharyngeal strictures were present in 24.10% of the patients. Long-term follow-up results were obtained in the period between 1 to up to 30 years. Early postoperative complications occurred in 26.48% of patients, among which anastomosic leakage was the most common. The operative mortality rate was 4.16% and late postoperative complications were present in 13.99% of the patients. A long-term follow up obtained in 84.82% of the patients found excellent functional results in 75.89% of them. We conclude that a colon graft is an excellent esophageal substitute for patients with esophageal corrosive strictures, and when used by experienced surgical teams it provides a low rate of postoperative morbidity and mortality, and long-term good and functional quality of life. [source]

Long-segment substernal jejunal esophageal replacement with internal mammary vascular augmentation

R. F. Heitmiller
We describe a technique that uses the internal mammary vessels to enhance long-segment jejunal graft blood supply in addition to an intact distal mesenteric vascular arcade. We believe that this technique, called vascular augmentation, improves jejunal graft perfusion and decreases ischemic complications. [source]

Angioplasty and stenting of symptomatic and asymptomatic vertebral artery stenosis: to treat or not to treat

V. Parkhutik
Background and purpose:, Comprehensive indications for treatment of symptomatic vertebral stenosis remain unavailable. Even less is known about endovascular treatment of asymptomatic cases. We treated symptomatic and asymptomatic vertebral ostium stenosis with angioplasty and stenting and investigated the long term outcome. Methods:, Consecutive patients with two different indications were included. Group 1 (G1) had symptomatic >50% stenosis. Group 2 (G2) had asymptomatic >50% stenosis and severe lesions of anterior circulation and were expected to benefit from additional cerebral blood supply. Results:, Twenty nine vertebral origin stenoses in 28 patients (75% men, mean age 64 ± 9 years) were treated. There were 16 G1 and 13 G2 cases. Technical success rate was 100%. Immediate neurological complications rate was 3.4% (one G1 patient with vertebral TIA due to release of emboli). Two further strokes were seen during follow up (32 ± 24 months): vertebrobasilar stroke in a G2 patient with permeable stent in V1 segment, new ipsilateral V3 occlusion and high-risk cardioembolic source, and carotid stroke in a G1 patient who had had ipsilateral carotid stenting. There were no deaths of any cause. Asymptomatic restenosis was observed in one out of 19 patients from both groups who underwent a follow up angiography. Conclusions:, Angioplasty and stenting appears to be technically feasible and safe in asymptomatic and symptomatic vertebral stenosis. More studies are needed in order to clarify its role in primary and secondary prevention of vertebrobasilar stroke. High risk anterior circulation lesions should be taken into account as a possible indication in patients with asymptomatic vertebral stenosis. [source]

Safety and supply of haemophilia products: worldwide perspectives

HAEMOPHILIA, Issue 4 2004
A. Farrugia
Summary., The survival and well-being of people with haemophilia depends on the supply of safe therapeutic products. Safety and supply are entirely intertwined principles; in the absence of adequate amounts of coagulation products, safety measures may be compromised in order to enhance supply, leading to risks which may result in morbidity and mortality. As haemophilia therapy has emerged through the development of blood transfusion and plasma fractionation, the safety of the blood supply in general has had a strong effect on haemophilia care. Despite the gradual detachment of haemophilia care from blood transfusion through the use of recombinant products, the majority of the world's population with haemophilia in the developing world will be reliant on blood products for the foreseeable future. It is, therefore, important to continue efforts for a safe and sufficient blood supply worldwide. As such a blood supply develops, possibly in tandem with an independent plasma fractionation industry, the level of haemophilia care should improve with the gradual introduction of concentrates for the ultimate goal of covering all aspects of care. Constant vigilance for the threat of blood-borne pathogens should be linked to considerations of how these products are to be manufactured. This should be governed entirely by considerations of safety and pharmaceutical competence. Of equal importance is a governmental capacity to oversee the entry and maintenance of these products on the market. While it is not possible for all countries to have a regulatory authority of the same status as that of the developed countries, it is perfectly feasible to develop a set of basic principles which allow an assessment of basic product safety, quality and efficacy to be made. [source]

Regulatory processes interacting to maintain hepatic blood flow constancy: Vascular compliance, hepatic arterial buffer response, hepatorenal reflex, liver regeneration, escape from vasoconstriction

W. Wayne Lautt
Constancy of hepatic blood flow (HBF) is crucial for several homeostatic roles. The present conceptual review focuses on interrelated mechanisms that act to maintain a constant HBF per liver mass. The liver cannot directly control portal blood flow (PF); therefore, these mechanisms largely operate to compensate for PF changes. A reduction in PF leads to reduced intrahepatic distending pressure, resulting in the highly compliant hepatic vasculature passively expelling up to 50% of its blood volume, thus adding to venous return, cardiac output and HBF. Also activated immediately upon reduction of PF are the hepatic arterial buffer response and an HBF-dependent hepatorenal reflex. Adenosine is secreted at a constant rate into the small fluid space of Mall which surrounds the terminal branches of the hepatic arterioles, portal venules and sensory nerves. The concentration of adenosine is regulated by washout into the portal venules. Reduced PFreduces the washout and the accumulated adenosine causes dilation of the hepatic artery, thus buffering the PF change. Adenosine also activates hepatic sensory nerves to cause reflex renal fluid retention, thus increasing circulating blood volume and maintaining cardiac output and PF. If these mechanisms are not able to maintain total HBF, the hemodynamic imbalance results in hepatocyte proliferation, or apoptosis, by a shear stress/nitric oxide-dependent mechanism, to adjust total liver mass to match the blood supply. These mechanisms are specific to this unique vascular bed and provide an excellent example of multiple integrative regulation of a major homeostatic organ. [source]

Surgical anatomy of the biliary tract

HPB, Issue 2 2008
Abstract An intimate knowledge of the morphological, functional, and real anatomy is a prerequisite for obtaining optimal results in the complex surgery of extra and intrahepatic cholangiocarcinoma. A complete presentation of the surgical anatomy of the bile ducts includes study of the liver, hepatic surface, margins, and scissures. The frequent variations from the normal anatomy are described and an overview of the blood supply and lymphatics of the biliary tract is presented. [source]

Detection of different tumor growth kinetics in single transgenic mice with oncogene-induced mammary carcinomas by flat-panel volume computed tomography

Katharina Jannasch
Abstract Transgenic mouse models offer an excellent opportunity for studying the molecular basis of cancer development and progression. Here we applied flat-panel volume computed tomography (fpVCT) to monitor tumor progression as well as the development of tumor vasculature in vivo in a transgenic mouse model for oncogene-induced mammary carcinogenesis (WAP-T mice). WAP-T mice develop multiple mammary carcinomas on oncogene induction within 3 to 5 months. Following induction, 3-dimensional fpVCT data sets were obtained by serial single scans of entire mice in combination with iodine containing contrast agents and served as basis for precise measurements of tumor volumes. Thereby, we were able to depict tumors within the mammary glands at a very early stage of the development. Tumors of small sizes (0.001 cm3) were detected by fpVCT before being palpable or visible by inspection. The capability to determine early tumor onset combined with longitudinal noninvasive imaging identified diverse time points of tumor onset for each mammary carcinoma and different tumor growth kinetics for multiple breast carcinomas that developed in single mice. Furthermore, blood supply to the breast tumors, as well as blood vessels around and within the tumors, were clearly visible over time by fpVCT. Three-dimensional visualization of tumor vessels in high resolution was enhanced by the use of a novel blood pool contrast agent. Here, we demonstrate by longitudinal fpVCT imaging that mammary carcinomas develop at different time points in each WAP-T mouse, and thereafter show divergent growth rates and distinct vascularization patterns. © 2009 UICC [source]

Osteoprotegerin (OPG),a potential new role in the regulation of endothelialcell phenotype and tumour angiogenesis?

Simon S. Cross
Abstract The progression of cancer depends on the establishment of a tumour blood supply, and therefore tumour angiogenesis has been identified as a major target for new anticancer agents. Recent reports have suggested that osteoprotegerin (OPG) is involved in the control of endothelial cell survival through the inhibition of the activity of tumour necrosis factor- (TNF) related apoptosis-inducing ligand (TRAIL). The role of OPG in human tumour development and angiogenesis is currently unknown. In the present study we demonstrate the ability of OPG to support endothelial cell survival, as well as the formation of cord-like structures in vitro using a matrigel tubule formation assay. Investigation of various human cancers demonstrated endothelial OPG expression in 59% of malignant tumours (n = 512), but in contrast, OPG was absent in endothelial cells associated with benign tumours and normal tissues (n = 178). In a series of 400 breast tumours, endothelial OPG expression was associated with high tumour grade and certain histological types. Our data show a clear separation in endothelial OPG expression between malignant tumours and nonmalignant tissues, supporting a potential biological role for this molecule in the development and/or maintenance of the tumour vasculature. This is the first study to report the proangiogenic effects of OPG in vitro, as well as correlating expression of OPG by tumour endothelial cells with clinicopathological data in human tumours. © 2005 Wiley-Liss, Inc. [source]

PDE5 inhibitors in diabetic peripheral neuropathy

Summary Peripheral neuropathy is the most common complication of diabetes. This paper reviews the case histories of five patients with diabetic peripheral neuropathy or severe peripheral vascular disease who reported improvement in their symptoms when treated with regular or daily dosing with phosphodiesterase type 5 inhibitors (PDE5Is). These patients had been previously treated with PDE5Is for erectile dysfunction (ED) and not responded to on-demand therapy with a PDE5I at maximal recommended dose. This improvement is likely to be due to the known benefit of these drugs on endothelial dysfunction via an improvement of blood supply to the vasa nervorum. These cases suggest that further research is indicated to evaluate the potential use of PDE5Is in the treatment and prevention of diabetic peripheral neuropathy, particularly as these drugs are already licensed to treat ED, which occurs in around 50% of male diabetics. [source]

Urological complications in 980 consecutive patients with renal transplantation

Aim: To present the urological complications of renal transplantations performed in the last 14 years at one center and to briefly explain a modified method of Lich,Gregoir ureteroneocystostomy. Methods: The data of 980 patients receiving kidney transplants at the authors' institution from April 1991 to February 2004 were reviewed in a retrospective prospective study. In particular, surgical techniques and urological complications were noted. Results: A total of 980 patients had received kidney transplantation. Extravesical ureteroneocystostomy (Lich,Gregoir method) was used in the first 480 patients (group A). In the subsequent 500 patients, the authors' modified method of extravesical ureteroneocystostomy, using single layer anastomosis and small feeding tubes as stent, was used (group B). Overall urological complication rate was 2.8% (28 patients), including leakage (13 patients, 1.3%), stenosis (seven, 0.7%), obstruction (one, 0.1%), distal ureter necrosis (four, 0.4%), pelvocalyceal fistula (two, 0.2%) and implantation of ureter into the peritoneum (one, 0.1%). Urological complications were significantly more common in group A compared to group B (16, 3.3% and 9, 1.8%, respectively; P < 0.05). Conclusions: Preserving the adventitia, fat and blood supply of the ureter by delicate dissection of the ureter during donor nephrectomy, short ureters, and fixation of the adventitia, fat and blood supply of the ureter to the bladder wall, to prevent kinking or twisting, are important factors in decreasing urological complications. Additionally, the authors' method of ureteroneocystostomy is also effective in decreasing the incidence of ureteric complications. [source]

Risk modelling in blood safety , review of methods, strengths and limitations

B. Custer
Risk modelling studies in blood safety play an important but occasionally misunderstood role. These studies are intended to quantify and contrast risks and benefits. This information is critical for policy development and intervention decision-making. The limitations of risk modelling should be considered alongside the results obtained. The goal of this manuscript and presentation is to review current risk modelling techniques used in blood safety and to discuss the pros and cons of using this information in the decision-making process. The types of questions that can be answered include the extent of a risk or threat; implications of action or inaction; identification of effective strategies for risk management; or whether to adopt specific interventions. These analyses can be focused on a risk alone but are often combined with economic information to gain an understanding of feasible risk interventions given budgetary or other monetary considerations. Thus, analyses that include risk modelling provide insights along multiple lines. As important, the analyses also provide information on what is not known or uncertain about a potential hazard and how much that uncertainty may influence the decision-making process. Specific examples of the range of risk analyses in which the author has participated will be reviewed and will include ongoing process improvement in testing laboratories such as error identification/eradication, estimation of the risk of malaria exposure based on the specific locations of travel, evaluation of blood supply and demand during an influenza pandemic, cost-utility analyses of screening interventions for infectious diseases in countries with different human development indices, and insurance against emerging pathogen risk. Each of these analyses has a different purpose and seeks to answer different questions, but all rely on similar methods. The tool kit for risk analysis is broad and varied but does have limitations. The chief limitation of risk modelling is that risk analyses are not scientific experiments or otherwise controlled studies. Consequently, the analyses are more apt to be influenced by assumptions. These assumptions may be necessary to structure a problem in a way that will allow the question of interest to be answered or may result from incomplete or missing information. Another potential limitation is that commissioners of such studies, those who undertake them, and the intended audience, such as regulatory agencies, may have distinct and differing interpretations of the results. Risk modelling is a set of techniques that can be used to inform and support decision-making at all levels in transfusion medicine. Advances in risk modelling techniques allow for continued expansion in the scope of possible questions that can be analysed. Expanded use also improves the acceptance of the utility of these studies in blood safety and transfusion medicine. [source]

Pathogen-reduction methods: advantages and limits

H. G. Klein
Pathogen-reduction (inactivation) provides a proactive approach to reducing transfusion-transmitted infection. Pathogen-reduction technologies have been successfully implemented by plasma fractionators resulting in no transmission of human immunodeficiency, hepatitis C, or hepatitis B viruses by US-licensed plasma derivatives since 1987. Fractionation technologies cannot be used to treat cellular blood components. Although blood donor screening, deferral and disease testing have drastically reduced the incidence of transfusion-transmitted diseases, the threat of new or re-emerging pathogens remains. Of particular concern is the silent emergence of a new agent with a prolonged latent period in which asymptomatic infected carriers would donate and spread infection. The ultimate goal of pathogen-inactivation is to reduce transmission of potential pathogens without significantly compromising the therapeutic efficacy of the cellular and protein constituents of blood. The acceptable technology must not introduce toxicities into the blood supply nor result in neoantigen formation and subsequent antibody production. Several promising pathogen-inactivation technologies are being developed and tested, and others are currently in use, but all of them have limits. Pathogen-reduction promises an additional ,layer of protection' from infectious agents and has the potential to impact the safety of blood transfusions worldwide. [source]

Rationale for medical director acceptance or rejection of allogeneic plateletpheresis donors with underlying medical disorders

Ronald G. Strauss
Abstract A survey was completed by 25 medical directors at different institutions performing plateletpheresis. The practices of these 25 physicians were analyzed regarding the acceptance/rejection of plateletpheresis donors with a history of cardiac disease/surgery, seizures/epilepsy, cancer, or autoimmune diseases. Although available medical literature documents little risk of these disorders either to donors (i.e., donation reactions) or to transfusion recipients (i.e., disease transmission), up to 24% of medical directors outright reject some of these potential donors while others accept patients/donors with these illnesses, providing they meet certain medical/health criteria. Acceptance/rejection of individuals with medical disorders has relevance for the availability of the blood supply and blood product shortages because several million Americans, diagnosed with these illnesses, represent a sizable pool of potential blood and platelet donors. J. Clin. Apheresis 17:111,117, 2002. © 2002 Wiley-Liss, Inc. [source]

Long-term effect of varicocele repair on intratesticular arterial resistance index

Ali Balci MD
Abstract Purpose To investigate the long-term effect of varicocele repair on ipsilateral intratesticular arterial resistance index (RI) using color Doppler sonography (CDS). Methods A total of 26 infertile patients with left varicocele who underwent a testicular artery and lymphatic-sparing subinguinal varicocelectomy were examined with CDS for intratesticular flow parameters before and at least 6 months after surgery. We also evaluated preoperative and postoperative semen parameters. Results The mean values of RI, end-diastolic velocity and pulsatility index decreased significantly after surgery, whereas no significant change was observed in peak systolic velocity. Repair of the varicocele resulted in a statistically significant increase in the total sperm count, motility, morphology, and total motile sperm count. However, no significant correlation was found between sperm parameters and RI values (p > 0.05). Conclusions Our data show that a significant improvement occurs in testicular blood supply and sperm parameters after surgical varicocele repair, without significant correlation between these 2 changes. © 2007 Wiley Periodicals, Inc. J Clin Ultrasound, 2008 [source]

Hepatic arterial flow becomes the primary supply of sinusoids following partial portal vein ligation in rats

Yukihiro Yokoyama
Abstract Background and Aim:, Partial portal vein ligation (PPVL) is a commonly used procedure to induce prehepatic portal hypertension in animal models. The aim of this study was to test the hypothesis that the hepatic arterial flow becomes the primary source feeding the sinusoids in the liver after PPVL. Methods:, Sprague,Dawley rats underwent either sham operation or partial portal vein ligation (PPVL). The number of vessels in the liver at 2 weeks postoperatively was determined by factor VIII immunolocalization and the gene expression of angiogenic factors was assessed by RT-PCR. The total hepatic arterial supply to the liver was measured using the fluorescent microsphere injection technique. To further test the hypothesis, two additional groups of rats underwent hepatic artery ligation (HAL) or PPVL plus HAL (PPHAL). The integrity of hepatic microcirculation was then evaluated in all four groups by intravital microscopy. Results:, At 2 weeks after operation, the number of vessels detected by factor VIII staining was significantly higher in PPVL compared to sham. Densitometric analysis of RT-PCR bands revealed a significant increase of vascular endothelial growth factor gene expression in PPVL compared to sham. Arterial flow to the liver measured by fluorescent microspheres was increased by 190% in PPVL compared to sham. When all four groups were compared, no prominent histological abnormality was observed in sham, HAL, and PPVL groups; however, PPHAL livers showed focal necrosis and inflammatory cell infiltration around the portal triads. Additionally, only the PPHAL livers showed a decreased sinusoidal diameter and significantly lower perfusion index (PPHAL 42.9 ± 6.1; sham 85.7 ± 7.0, PPVL 80.2 ± 6.5, HAL 70.9 ± 4.5). Conclusions:, These results suggest that the hepatic artery flow becomes the primary source for the blood supply of sinusoids and the compensatory change in the hepatic arterial system plays a critical role in maintaining microcirculatory perfusion following the restriction of the portal vein flow by PPVL. [source]

Pathogen inactivation technology: cleansing the blood supply

Abstract., Klein HG (The Johns Hopkins School of Medicine and Warren G. Magnuson Clinical Center, National Institutes of Health, Bethesda, MD, USA). Pathogen inactivation technology: cleansing the blood supply (Review). J Intern Med 2005; 257: 224,237. The calculated residual infectious risk of HIV, hepatitis B virus (HBV) and hepatitis C virus (HCV) from blood transfusion is extremely low. However, the risk of bacterial contamination remains and a variety of other agents including emerging viruses, protozoa and tick-borne agents threaten blood supplies and undermine public confidence in blood safety. Traditional methods of donor screening and testing have limited ability to further reduce disease transmission and cannot prevent an emerging infectious agent from entering the blood supply. Pathogen inactivation technologies have all but eliminated the infectious risks of plasma-derived protein fractions, but as yet no technique has proved sufficiently safe and effective for traditional blood components. Half-way technologies can reduce the risk of pathogen transmission from fresh frozen plasma and cryoprecipitate. Traditional methods of mechanical removal such as washing and filtration have limited success in reducing the risk of cell-associated agents, but methods aimed at sterilizing blood have either proved toxic to the cells or to the recipients of blood components. Several promising methods that target pathogen nucleic acid have recently entered clinical testing. [source]

Toward an Implantable Wireless Cardiac Monitoring Platform Integrated with an FDA-Approved Cardiovascular Stent

Continuous monitoring of blood pressure from a minimally invasive device in the pulmonary artery can serve as a diagnostic and early warning system for cardiac health. The foremost challenge in such a device is the wireless transfer of data and power from within the blood vessel to an external device while maintaining unrestricted flow through the artery. We present a miniaturized system, which is attached to the outer surface of a regular or drug-eluting FDA-approved stent. When expanded, the stent maintains a patent vessel lumen while allowing contact between the electronic sensors and the blood supply. The stent-based antenna can be used for both wireless telemetry and power transfer for the implanted electronics. Using the stent platform as both a radiating antenna and a structural support allows us to take advantage of an FDA-approved device whose safety and surgical procedure are well established. The electronics package has been reduced to an area of less than 1 mm2, with a thickness under 300 ,m. A minimally invasive implantation procedure allows the delivery of the stent-based implant in nearly any major vessel of the body. This article describes an initial prototype with two stents configured as a single dipole, a 2.4-GHz transmitter microchip, and a battery, and validates transcutaneous transmission through ex vivo and in vivo porcine studies. The results demonstrate the feasibility of a stent-based wireless platform for continuous monitoring of blood pressure. [source]

Imaging in bronchopulmonary sequestration

P Abbey
Summary Bronchopulmonary sequestration is an uncommon pulmonary disorder characterized by an area of non-functioning abnormal lung tissue, which receives its blood supply from a systemic artery and characteristically has no connection with the tracheobronchial tree. The abnormal lung tissue is located within the visceral pleura of a pulmonary lobe in the intralobar variety, whereas the extralobar form has its own visceral pleura. The venous drainage of the extralobar type is usually into the systemic veins, whereas the intralobar type drains into the pulmonary veins. Radiological imaging plays a vital role in establishing the diagnosis, and even more importantly, in providing to the clinician a vascular roadmap essential for surgical planning. We present here a review of bronchopulmonary sequestration and also discuss the role of various imaging methods in the early diagnosis and management of these cases. [source]

Effective poxvirus removal by sterile filtration during manufacture of plasma derivatives,

A. Berting
Abstract As a consequence of the September 2001 terrorist events, programs to protect against further such acts including potentially the use of biological warfare agents have been launched in the USA and elsewhere. As part of these initiatives, Vaccinia virus was procured for the pre-emptive vaccination of key personnel against smallpox as well as population-wide protection after an eventual exposure. The introduction of this live virus into a population at a relatively large scale represents a theoretical challenge for the safety of the blood supply, and potentially for plasma for fractionation. To strengthen further the demonstration of safety margins for plasma derived products against Vaccinia virus, the capacity of sterile filtration procedures to remove the virus was investigated. An infectivity assay for the Vaccinia virus strain which represents the majority of smallpox vaccine stocks available currently was used to investigate the potential removal of this virus by sterile filtration processes during the manufacture of plasma derivatives. Vaccinia virus behaves as predicted based on its size, i.e., an artificially added virus load is removed about 10,000-fold by the sterile filtration procedures tested. As the current investigation covered a range of different protein concentrations, filter materials and filters from different manufacturers, the results obtained are considered to be widely applicable. The current investigation supports further the high safety margins of plasma derivatives against any potential Vaccinia virus content of plasma for fractionation. As the large size is a general feature of Orthopox viruses, the results would also provide assurance against poxviruses identified more recently, for example, Monkeypox virus. J. Med. Virol. 75:603,607, 2005. © 2005 Wiley-Liss, Inc. [source]

Cerebral ischemia/stroke and small ubiquitin-like modifier (SUMO) conjugation , a new target for therapeutic intervention?

Wei Yang
Abstract Transient cerebral ischemia/stroke activates various post-translational protein modifications such as phosphorylation and ubiquitin conjugation that are believed to play a major role in the pathological process triggered by an interruption of blood supply and culminating in cell death. A new system of post-translational protein modification has been identified, termed as small ubiquitin-like modifier (SUMO) conjugation. Like ubiquitin, SUMO is conjugated to the lysine residue of target proteins in a complex process. This review summarizes observations from recent experiments focusing on the effect of cerebral ischemia on SUMO conjugation. Transient global and focal cerebral ischemia both induced a rapid, dramatic and long-lasting rise in levels of SUMO2/3 conjugation. After transient focal cerebral ischemia, SUMO conjugation was particularly prominent in neurons located at the border of the ischemic territory where SUMO-conjugated proteins translocated to the nucleus. Many SUMO conjugation target proteins are transcription factors and sumoylation has been shown to have a major impact on the activity, stability, and cellular localization of target proteins. The rise in levels of SUMO-conjugated proteins is therefore likely to have a major effect on the fate of post-ischemic neurons. The sumoylation process could provide an exciting new target for therapeutic intervention. [source]

Nitric oxide signalling in salivary glands

Dagnia Looms
Abstract Nitric oxide (NO) plays multiple roles in both intracellular and extracellular signalling mechanisms with implications for health and disease. This review focuses on the role of NO signalling in salivary secretion. Attention will be paid primarily to endogenous NO production in acinar cells resulting from specific receptor stimulation and to NO-regulated Ca2+ homeostasis. Due to the fact that NO readily crosses membranes by simple diffusion, endogenous NO may play a physiological role in processes as diverse as modifying the secretory output, controlling blood supply to the gland, modulating transmitter output from nerve endings, participating in the host defence barrier, and affecting growth and differentiation of surrounding tissue. Furthermore, the role of NO in the pathogenesis of human oral diseases will be considered. [source]

Effect of cortical thickness and cancellous bone density on the holding strength of internal fixator screws

J. Seebeck
Abstract Internal fixators are a new class of implants designed to preserve the periosteal blood supply of the bone. In contrast to conventional plate fixation in which the screws have spherical heads and are loaded mainly by axial pullout forces, screws in internal fixators are "locked" within the plate and therefore subjected to axial as well as bending loads. In this study the ultimate loads of screws of a commercially available internal fixator system were tested in a pullout (n = 72) and cantilever bending mode (n = 72) in metaphyseal and diaphyseal regions of four pairs of human tibiae with different bone qualities. Cortical thickness and cancellous bone density were determined at the screw insertion sites. Stepwise multiple linear regression revealed that cortical thickness and cancellous density can explain 93% and 98% of the variance of the ultimate load of the screws in an axial pullout and cantilever bending mode. Screws in internal fixators are better suited to transmit shear forces and thereby make better use of the strength potential of bone than screws used in conventional plate fixation: this is especially advantageous when bone strength is reduced, e.g. due to osteoporosis. © 2004 Orthopaedic Research Society. Published by Elsevier Ltd. All rights reserved. [source]

Multipotency of clonal cells derived from swine periodontal ligament and differential regulation by fibroblast growth factor and bone morphogenetic protein

K. Shirai
Background and Objective:, A blood supply is indispensable for the regeneration of damaged or lost periodontal ligament (PDL) tissue. Mesenchymal stem cell-like activity of cells derived from the PDL has been identified by their capacity to form fibrous and osseous tissue and cementum. However, it remains to be clarified whether the cells have an ability to build the capillary network of blood vessels. This study evaluated the potential of cells derived from the PDL to construct a blood vessel-like structure and examined how growth factors controlled the multipotency of the cells. Material and Methods:, The ability of a swine PDL fibroblast cell line, TesPDL3, to construct a blood vessel-like structure was evaluated on and in the self-assembling peptide scaffold, PuraMatrixTM. In addition, the ability of the cells to form mineralized nodules was evaluated on type I collagen-coated plastic plates. In some cases, fibroblast growth factor (FGF)-2 and bone morphogenetic protein (BMP)-2 were added to these cultures. The status of the expression of vascular and osteoblastic cell-specific markers in the cells was evaluated using reverse transcriptase-polymerase chain reaction (RT-PCR), Western blotting and immunofluorescence analyses. Results:, The TesPDL3 cells not only formed mineralized nodules in response to BMP-2 stimulation but also constructed tube-like structures in response to FGF-2 stimulation. Intriguingly, FGF-2 inhibited the BMP-2-induced formation of mineralized nodules. Conversely, BMP-2 inhibited the FGF-2-induced formation of tube-like structures. Conclusion:, Periodontal ligament fibroblasts have the potential to differentiate not only into osteoblastic but also into vascular cell lineages. The destiny of the cells was reciprocally regulated by BMP-2 and FGF-2. [source]