Biomedical subjects

Gaurang Shah

Publications and source records attributed to Gaurang Shah.

17 recordsLinked to original sources

PubMed2006

Ureteral access sheath for the management of pediatric renal and ureteral stones: a single center experience.

PURPOSE: Ureteral access sheaths were developed to facilitate difficult ureteroscopic access in adults. We report our use of the ureteral access sheath during standard ureteroscopic procedures in the pediatric stone population. MATERIALS AND METHODS: Eight patients underwent flexible ureteroscopy and holmium laser lithotripsy for symptomatic renal and ureteral calculi between October 2003 and October 2004. Average patient age was 9.3 years (range 4 to 13). There were 4 males and 4 females. Five of 8 patients had bilateral stones and underwent bilateral endoscopic stone treatment at the same operation. A 14Fr 20 cm Flexor ureteral access sheath was used for dilation and access of the ureter. Flexible pediatric ureteroscope was used to enter the ureter and collecting system for stone retrieval and fragmentation. RESULTS: All patients were rendered stone-free in a single operative setting. Average operative time was 99 minutes (range 65 to 130). Average total stone burden for the group was 9 +/- 3 mm. All patients received stents after the procedure. There were no perioperative complications. All patients were followed with renal-bladder ultrasound and plain x-ray. All patients were stone-free at a mean followup of 10 months (median 11). CONCLUSIONS: Routine use of a ureteral access sheath in children facilitates flexible ureteroscopy with lithotripsy of multiple renal and proximal ureteral stones. The procedure is safe and time efficient, and is associated with minimal morbidity. Larger prospective studies in children with longer followup are warranted.

Adolescent↗

PubMed2006

Population trends in leisure-time physical activity: Minnesota Heart Survey, 1980-2000.

PURPOSE: Twenty-year trends in lifestyle (leisure, household, and transportation related) physical activity and leisure-time physical activity (LTPA) were evaluated in the Minnesota Heart Survey (MHS), a population-based surveillance study to monitor trends in cardiovascular risk factor levels among residents of the Minneapolis-St. Paul metropolitan area. METHODS: The Minnesota LTPA questionnaire was administered to adult participants in one of five cross-sectional MHS surveys conducted in 1980 (N = 1626), 1985 (N = 2292), 1990 (N = 2552), 1995 (N = 2432), and 2000 (N = 3089). Occupational activity was queried in 1980, 1995, and 2000. Age-adjusted, gender-specific geometric means of lifestyle physical activity and LTPA and of light-, moderate-, and vigorous-intensity activities were calculated for each survey. The proportion of adults participating in regular physical activity for 30 and 60 min x d(-1) was reported. RESULTS: Male gender, younger age, higher educational status, and employment were characteristic of greater participation in physical activity. Daily energy expenditure from lifestyle physical activity and LTPA increased between 1980 and 2000 in both genders, and workplace activity decreased. Using direct questions, the prevalence of men and women participating in 30 or more minutes of physical activity at least five times per week ranged from 8 to 12%, with no time trend. Only 1% of participants participated 60 min daily. Overall, BMI was 1-2 kg x m(-2) lower among individuals who participated regularly in physical activity. CONCLUSIONS: Although energy expenditure was lower than national recommendations, greater physical activity was associated with lower body mass. Public health strategies are needed to facilitate participation in physical activity, especially for women, elderly, and less educated individuals.

Adult↗

PubMed2005

Impact of prostate size and body mass index on perioperative morbidity after laparoscopic radical prostatectomy.

PURPOSE: We prospectively evaluated the impact of body mass index (BMI) and prostate gland size on operative time, estimated blood loss (EBL) and hospital stay (LOS) in patients undergoing laparoscopic radical prostatectomy at our institution. MATERIALS AND METHODS: A total of 70 consecutive laparoscopic radical prostatectomies were performed at our institution from May 2002 to April 2003. Patients who had pelvic lymphadenectomy were excluded. A total of 62 cases were available for analysis. Two cases were converted to open surgery. Perioperative data on each group were recorded, including patient age, height, weight, American Society of Anesthesiologists score, prostate specific antigen, operative time, EBL, time to regular diet and LOS. Pathology data, including specimen weight, Gleason score and the margin status, were reviewed. Patients were grouped into 3 categories based on obesity, as measured by BMI (25 or less, 26 to 29 and greater than 29 kg/m) and prostatic gland size (less than 30, 30 to 50 g, and greater than 50 gm). Furthermore, an analysis of our initial 20, middle 20 and last 22 cases was also performed. RESULTS: Mean patient age was 63 years and mean American Society of Anesthesiologists score was 2.4. Mean operative time was 247 minutes and average EBL was 413 cc. The average LOS in all groups was 2.2 days. There were no statistically significant differences in operative parameters (operative time, EBL or LOS) among the ideal body weight (BMI 25 kg/m or less), overweight (BMI 26 to 29) and obese (BMI greater than 29) groups. The initial 20 cases, the second 20 and the last 22 had similar operative time, EBL and LOS. The surgical margin positive rate in our series was 17.7% for all stages. Of the patients 82% were completely dry at 6 months. CONCLUSIONS: In our cohort of patient body mass index (25 or less, 26 to 29 and greater than 29 kg/m) did not have a significant impact on operative or postoperative morbidity. However, a positive correlation between prostate gland size (greater than 50 gm) and EBL approached but did not achieve statistical significance. Laparoscopic prostatectomy can be performed safely in obese patients and patients with a large prostate gland.

Adult↗

PubMed2005

Controversies in the diagnosis and management of urinary tract infections in children.

Urinary tract infection (UTI) is one of the most common childhood bacterial infections, after upper respiratory tract and middle ear infections. The current goal of management is to prevent detrimental effects of UTI by early detection and treatment. Recommendations for the imaging of children depend upon age at presentation and sex. All children aged <5 years who have had a febrile UTI require a radiologic evaluation to identify any underlying genitourinary pathology. Older children can undergo a more tailored work-up depending on whether there is a febrile UTI or cystitis-type symptoms. Dysfunctional voiding and urge syndrome significantly increase the risk of developing UTIs in children. Vesicoureteral reflux can increase the risk of pyelonephritis and renal scarring in children with UTIs. For the most part, pyelonephritis can be diagnosed on clinical grounds in the majority of patients and a subsequent (99m)Tc-dimercaptosuccinic acid scan can be reserved to identify post-nephritic renal scarring. When renal scarring is identified, the child and parents need to be educated regarding the possibility of hypertension, proteinuria, progressive nephropathy, and the risk of complications in future pregnancies. Treatment of UTI is started in the unwell child before the culture results are available and subsequently changed to culture-specific antimicrobial therapy. A short course of treatment is required for acute uncomplicated UTIs. A child with acute pyelonephritis requires 10-14 days of antibacterial treatment. The oral route in young children often causes vomiting, which implies therapeutic delay, a well known risk factor for scarring.

Anti-Bacterial Agents↗

PubMed2004

The effect of allo-injury in an in vitro model of allograft microvasculature.

Endothelial cells are critical to the integrity of allograft vasculature and can be damaged by alloreactive T cells or soluble mediators of alloreactivity. The biochemical effects of T cell-mediated damage to the endothelial cells have been studied, but not the structural and morphological effects of allo-injury on endothelial cells in the allograft. We utilized an assay that reproduces microvasculature in vitro to study the effect of alloreactivity on endothelial cells. In this assay, endothelial cells are induced into capillary-like networks that simulate microvascular capillaries. We studied the effect of allogeneic T cells and of soluble mediators from both mixed lymphocyte cultures (MLCs) and rejected heart allograft tissue on the in vitro capillaries. We found that both allogeneic T cells and soluble mediators inhibit the formation of the in vitro endothelial capillaries, suggesting that they cause a mild-to-moderate dysfunction of the endothelial cells. The inhibitory effect of the soluble mediators seems to be mediated, at least partly, by IFN-gamma, since this effect was prevented by antibody to IFN-gamma. Furthermore, pre-incubation of the in vitro capillaries with IFN-gamma appeared to magnify the effect of allogeneic T cells, as shown by a complete breakdown of well-formed in vitro capillary networks. Our experiments suggest that the in vitro capillary-tube model reflects structural injury to allograft vasculature by alloreactive T cells and their soluble mediators.

Animals↗

PubMed2004

Signal transduction pathway in endothelial dysfunction.

BACKGROUND: Endothelial dysfunction is an important feature of sepsis, acute respiratory distress syndrome (ARDS), and other infectious conditions. Previously, we reported an in vitro model to study endothelial dysfunction, in which endothelial cells are induced to form capillary tube networks by culturing on a basement membrane matrix (Matrigel). In this study, we defined the signal transduction pathways that lead to endothelial cell function and capillary disruption characteristic of sepsis and other infectious conditions. METHODS: Human aortic endothelial cells (HAEC) were cultured on a laminin-rich matrix to form capillary-like networks. The HAECs were treated with a protein tyrosine phosphatase inhibitor (sodium orthovanadate), a phosphoinositon-3-phosphate inhibitor (wortmannin), or a protein kinase C inhibitor (bisindolylmaleimide) before capillary tubes had formed or after the capillary tubes had matured. The degree of capillary tube formation was quantified by counting the intersection of capillary networks in triplicate wells. Statistical significance was determined by analysis of variance. RESULTS: Endothelial dysfunction occurred after inhibition of protein tyrosine phosphatase or protein kinase C. Whereas inhibition of phosphoinositon-3-phosphate did not cause endothelial dysfunction, sodium orthovanadate (2-20 microM) and bisindolylmaleimide (2-10 microM) significantly reduced capillary networks. The mean +/- SD of the number of capillary tubes in the control, sodium orthovanadate-treated, and bisindolylmaleimide-treated groups were 251.0 +/- 7.0, 65.6 +/- 9.9 (p < 0.001), and 181.7 +/- 0.1 (p < 0.001), respectively. Sodium orthovanadate (20-200 microM) and bisindolylmaleimide (10-100 microM) inhibited capillary tube formation. At higher concentrations, sodium orthovanadate (> 200 microM) and bisindolylmaleimide (>100 microM) disrupted mature capillary tubes. CONCLUSIONS: Our results suggest that PKC and protein tyrosine phosphatase play a role in endothelial dysfunction by interfering with the phosphorylation signals within endothelial cells. These mechanisms may be important in the endothelial dysfunction in sepsis and other infectious conditions.

Analysis of Variance↗

PubMed2004

Impact of temporary hilar clamping during laparoscopic partial nephrectomy on postoperative renal function: a prospective study.

PURPOSE: Laparoscopic partial nephrectomy for small renal tumors has been increasingly performed in the last few years. We prospectively evaluated preoperative and postoperative differential renal function by renal scan in patients with contralaterally functioning kidneys who underwent laparoscopic partial nephrectomy with hilar clamping. MATERIALS AND METHODS: From July 2002 to June 2003, 17 consecutive patients were included in this prospective protocol and underwent laparoscopic partial nephrectomy for exophytic tumors using en bloc hilar clamping. Preoperative renal scan with differential function was performed 1 month before and 3 months after surgery in all patients. technetium labeled diethylenetetraminepentaacetic acid scan was performed in all patients. RESULTS: Mean warm ischemia time was 22.50 +/- 9.78 minutes (range 10 to 44). Preoperative differential renal function and glomerular filtration rate (GFR) in the affected kidneys were 50.20% +/- 4.90% (range 43 to 58) and 75.56 +/- 16.45 ml per minutes (range 39.4 to 105). At postoperative month 3 differential renal function and GFR in the affected kidney were 48.07% +/- 7.16% (range 39% to 63%) and 72.03 +/- 18.17 ml per minutes (range 31 to 101). There was a nonsignificant negative association between hilar clamp time and change in renal function (postoperative - preoperative) of the affected kidney (r = -0.26, p = 0.31), and a positive correlation between clamp time and change in GFR (r = 0.39, p = 0.12) that did not reach statistical significance. CONCLUSIONS: In patients with contralaterally functioning kidney, temporary hilar clamping with a mean warm ischemia time of 22.5 minutes results in preservation of renal function in the affected kidney. Larger studies with longer followup are necessary to study the impact of warm ischemia further.

Adult↗

PubMed2004

Soluble interleukin 2 receptor (sIL-2R) levels in renal transplant recipients.

BACKGROUND: Allograft rejection is associated with T cell activation. T cell activation leads to secretion of soluble IL-2 receptor and elevated serum soluble IL-2 receptor (sIL-2R) levels. However, the clinical implication of individual elevated sIL-2 receptor levels is unclear. We followed levels of sIL-2R pre- and post-transplantation to determine if sIL-2R levels predict rejection episodes or degree of graft function. MATERIALS AND METHODS: Serum samples of 12 patients who underwent living or cadaveric renal transplant were followed weekly with serial sIL-2R levels. These levels were followed until the serum creatinine reached a baseline. Of the 12 patients, three patients developed delayed graft function. The remaining nine patients were followed for a period of 3 months. Sera of these nine patients in the initial 3 months post-transplant were monitored for sIL-2R levels. For comparison, sIL-2R levels were also measured in 150 healthy volunteers and five dialysis patients. RESULTS: Recipients undergoing severe rejection episodes had higher overall serum levels of sIL-2R (1515 +/- 496 U/mL) as compared with recipients who had stable renal transplants and no episodes of rejection (698 +/- 333 U/mL) (P = 0.034). Comparison of sIL-2R ratios (post-transplant sIL-2R level/pre-transplant sIL-2R level) revealed that ratios of 0.6 or higher were more frequently seen in patients who subsequently underwent severe rejection episodes. Dialysis patients were found to have higher sIL-2R levels (2605 +/- 1312 U/mL) compared with renal transplant patients (1047 +/- 192 U/mL) (P < 0.001) and healthy volunteers (349 +/- 185 U/mL) (P < 0.001). CONCLUSION: Our results suggest that individual levels of sIL-2R are not predictive of rejection in the early post-transplant period, but s-IL2R ratios greater than 0.6 may be predictive of severe rejection episodes.

Graft Rejection↗

PubMed2004

Cross-species comparison of gene expression between human and porcine tissue, using single microarray platform--preliminary results.

INTRODUCTION: Xenotransplantation is a potential solution for inadequate supply of donor organs. Pigs are considered the ideal donor for kidney transplantation to human recipients, therefore it is important to understand the gene regulation in the porcine organs. Oligonucleotide array technology has been utilized largely for human, mouse and rat gene expression studies only. Its use with porcine genes has not been reported. We investigated the possibility of studying gene regulation in porcine kidney with a human GeneChip microarray platform. METHODS: To assess the feasibility of using a single microarrray platform for comparison of expressing data across different species (human and pig), we compared the gene expression profiles of human brain, human kidney and pig kidney using the Affymetrix U-133 A human GeneChip, which contains probes for 22,283 genes. Kidney biopsies from pigs and humans, with normal histology, were used to obtain RNA for porcine and human samples, while a commercially available adult whole cortex total RNA sample (Clontech) was used for the human sample. We assessed the intensity ratio for housekeeping and tissue specific genes. To examine the potential for non-specific binding to create false positive errors in our data, we compared the expression profiles in our experiments to a number of public databases. RESULTS: There were approximately the same number of genes expressed at higher levels in the pig kidney as in the human kidney and human brain. The major differences in gene expression were found for genes with tissue specific patterns of expression. Eighty genes were increased in human brain vs. human and pig kidney samples. Two hundred and eighty genes were increased in human and pig kidney vs. human brain samples. Of the top 25 genes increased in pig kidney compared with human brain, we were able to cross-reference 18 genes to the Unigene and SAGE public databases. We confirmed the expected higher levels of expression in the kidney in 18 genes. Of the top 25 genes increased in human brain vs. pig kidney, we were able to cross-reference 20 genes to the Unigene and SAGE databases and confirm the expected higher expression levels in brain in 17 genes with three inconclusive genes. CONCLUSION: This low level of false positive findings, at this preliminary stage, supports the concept of using human GeneChip microarray platform to compare gene expression profiles between pig and human tissues in the absence of a porcine microarray platform. Our study opens a new avenue into the analysis of porcine genes relevant to xenotransplantation.

Animals↗

PubMed2004

Student evaluation practices in pediatric clerkships: a survey of the medical schools in the United States and Canada.

Despite the curriculum changes during the past decade, there is paucity of information regarding the structure and evaluation processes in pediatric clerkships. Information regarding the educational components of the pediatric clerkship and student evaluation practices was obtained from the pediatric clerkship directors via a paper/electronic survey. Completed surveys were received from 97 US and Canadian medical schools and were analyzed. The average length of a clerkship was 7 weeks. Most clerkships required a 4-week ward, a 1-week newborn rotation, and a 2-week ambulatory rotation. Students were evaluated on each component of the clerkship in 93.5% of the programs. All programs evaluated student's clinical performance and fund of knowledge; 85.6% evaluated student's written record. Student's clinical performance was evaluated by direct observation in 57% of the programs. Penalties for failing in clinical performance were harsher. In 56% of programs, a student failing in clinical performance failed the entire clerkship in contrast to 21.8% or 7% of the programs where a student failed the entire clerkship if they failed in the examination for the fund of knowledge or written record evaluation, respectively. The survey demonstrated a fair amount of consistency in clerkships across programs when compared with data obtained in 1981 and 1986. There was a noticeable increase in the well-baby nursery rotation; however, there was a decline in direct observation to assess physical examination or clinical performance.

Canada↗

PubMed2004

A novel extracorporeal kidney perfusion system: a concept model.

The number of patients awaiting kidney transplantation has more than doubled in the past decade while the number of available donor organs has seen only a modest increase, leading to a critical shortage of organs. In response to this extreme shortage, the criteria for accepting organs have been modified to include marginal donors such as non-heart beating donors (NHBD). In these kidneys, determining viability is important for success of transplantation. Therefore, a study was undertaken to develop a system that would allow the extracorporeal assessment of function and compatibility of the donor organ before the patient is exposed to the risks associated with surgery. Following bilateral nephrectomy, the kidneys of 10 pigs (approximately 30 kg) were connected to a commercially available hypothermic pulsatile kidney perfusion apparatus. This system was modified to allow for normothermic pulsatile renal perfusion using the potential recipient's blood, via vascular access. These kidneys were perfused with the animal's blood for a minimum of two hours while various parameters were monitored. Perfusion pressures were kept between 60 and 90 mmHg, which correlated to flows between 70 and 150 mL/min. A decrease in perfusion pressure with a concomitant rise in flow over the two-hour period served as a good predictor of a viable and compatible graft. The modified kidney preservation system allows the normothermic, pulsatile extracorporeal perfusion of donor kidneys with the ability to monitor resistance to flow and urine production. This model also allows observation of the kidney for signs of hyperacute rejection. Further research needs to be conducted in order to determine if the system represents a methodology to increase the pool of available donor organs.

Animals↗

PubMed2004

Augmentation of ischemia/reperfusion injury to endothelial cells by cyclosporin A.

Ischemia/reperfusion (I/R) carries significant injury to endothelial cells in transplanted organs and is an important factor in chronic rejection. Immunosuppressive drugs, notably cyclosporin A (CyA) and FK506, can potentially augment this injury. Here, our goal was to determine the combined effects of I/R and CyA or FK506 on endothelial cells. Transformed mouse endothelial cells (SVEC 4-10) were subjected to ischemia or I/R for 2-24 hours by incubating cells in 100 per cent N2 (ischemia) followed by 5 per cent CO2 and 95 per cent O2 (reperfusion) for 24 hours. In separate experiments, CyA or FK506 was added to cells subjected to ischemia or I/R. Nonviable cells were determined by Trypan blue exclusion assay. All experiments (done in triplicate) were analyzed by Student's t test. Increasing ischemia times resulted in a greater number of nonviable cells (2% nonviable cells at 0 hours and 57% at 24 hours of I/R). Addition of CyA significantly increased the number of nonviable cells when compared with the control (I/R only) group (P = 0.014). Interestingly, FK506 did not increase the percentage of nonviable cells compared with the control group (P = 0.2). Unlike FK506, CyA augments I/R injury to endothelial cells in vitro. These findings could be relevant in chronic rejection and transplantation.

Analysis of Variance↗

PubMed2003

Initial angiogenic response in reduced renal mass after transplantation.

INTRODUCTION: Shortage of organs is a major problem in kidney transplantation and requires novel strategies to increase the number of kidney transplants. To reduce the shortage of kidneys, we have proposed transplantation of two halves of one kidney into two recipients (hemirenal transplantation, HRT) and have shown its feasibility in pig and human kidneys. However, reduced renal mass can lead to progressive renal failure in rodents and can reduce the longevity of kidney transplants in humans. Recent studies suggest that derangement of angiogenesis plays a role in the progressive renal failure after reduction in renal mass in rodents. However, since the renal physiology of rats is different from that of large animals, we studied angiogenesis in reduced renal mass transplants in pigs and determined if the reduction in renal mass has the same effect in large animals as that in rodents. MATERIALS AND METHODS: Kidney autotransplantation was performed in domestic outbred swine. Heminephrectomy of the autotransplanted kidney and nephrectomy of the contralateral kidney were performed 1 week after transplantation to reduce the renal mass. Four weeks after transplantation, the pigs were sacrificed and the hemirenal and control nephrectomy specimens were processed for morphometric analysis of glomerular capillary density and immunohistochemical analysis of VEGF expression. Soluble extracts from the kidneys were tested in an in vitro angiogenesis assay to determine their activity to influence angiogenesis. Statistical analysis with ANOVA was performed on the glomerular capillary density in kidney specimens. RESULTS: All these parameters of angiogenesis were increased in the reduced renal mass autotransplants as compared to normal kidneys or whole kidney autotransplants. Glomerular capillary density was increased significantly after reduction in renal mass. VEGF expression also was increased progressively by the third week after reduction in renal mass. Soluble extract from the reduced renal mass transplants significantly increased the in vitro angiogenesis. CONCLUSION: This is the first study to demonstrate that angiogenesis is increased in the initial stages of reduction in renal mass after transplantation in a large animal model. Increased angiogenesis was found in this model earlier than reported in small animal models (2 weeks in pigs versus 6 weeks in rats). Taken together with other studies, our data suggest that derangement in angiogenesis could play an important role in long-term graft function after hemirenal transplantation.

Animals↗

PubMed2003

Amelioration of cyclosporin A effect on microvasculature by endothelin inhibitor.

BACKGROUND: We have previously shown that endothelial injury by cyclosporin A (CyA) is associated with an increased endothelin-1 (ET-1) release. We now sought to determine, in an animal model of angiogenesis, if inhibiting the effect of ET-1 on endothelial cells (ECs) would reverse the CyA-mediated endothelial injury in an animal model of angiogenesis. METHODS: An angiogenic mixture of Matrigel (0.5 ml), fibroblast growth factor (1 ng/ml), vascular endothelial growth factor (100 ng/ml), and heparin (64 unit/ml) was injected as a subcutaneous plug in the flank of C3H mice (n = 5). In experimental groups CyA (20 mg/ml), CyA, and BQ 123 (ET-A receptor antagonist), CyA and PD 142893 (ET-A and ET-B receptor antagonist), or CyA and ET-1 antibody were added to the angiogenic mixture. Angiogenesis in the mixture was quantified by modified planimetric point counting method in skin/Matrigel cross-sections stained with factor VIII to highlight endothelial neocapillaries. Mean +/- SD of angiogenic area was analyzed with analysis of variance and Bonferroni test. The survival curves obtained by Kaplan-Meier analysis were compared between the groups, and the statistical significance of survival and mortality rates was computed by log rank's and Fisher's exact test, respectively. RESULTS: The mean +/- SD of angiogenic area in control animals (without CyA in the angiogenic mixture) was 56.76 +/- 4.2. CyA inhibited angiogenesis in the subcutaneous angiogenic plug. Adding CyA to the angiogenic mixture significantly reduced angiogenic area (5.33 +/- 1.4, P <.001) while vehicle for CyA had no such effect (56.33 +/- 3.8, P =.10). Polyclonal ET-1 antibody or PD 142893 ameliorated the effect of CyA, whereas BQ 123 did not. The mean angiogenic areas in animals with ET-1 antibody, PD 142893, or BQ 123 in the angiogenic mixture were 57.20 +/- 7.5 (P =.06), 46.00 +/- 11.5 (P = 1.0), 8.60 +/- 2.9 (P <.001), respectively. CONCLUSIONS: Our data show that blocking ET-B receptors specifically ameliorates the microvascular injury to the neocapillaries in angiogenesis caused by CyA. Antiendothelin-1 antibody and ETR antagonist (PD 142893) could, therefore, reduce the ill effects of CyA on microvascular endothelium.

Animals↗

PubMed2003

Early hemodynamic changes after renal transplantation: determinants of low central venous pressure in the recipients and correlation with acute renal dysfunction.

BACKGROUND: Transplantation of organs leads to several physiologic changes in the recipients who, during their anephric state on chronic hemodialysis, have increased total body water and several electrolyte imbalances. Several abnormal parameters are observed in the physiology of the renal recipient. The central venous pressure (CVP) in the recipient invariably declines despite vigorous fluid resuscitation for reasons that are not clear at the present time. MATERIAL/METHODS: We studied 77 kidney transplants retrospectively, in which we observed a significant decline in central venous pressure (CVP) in the immediate posttransplant period. This phenomenon occurred despite aggressive fluid management and positive fluid balances averaging nearly four liters. Our analysis included the time course of the phenomenon itself as well as a detailed comparison of various parameters in the recipient and the renal graft for possible correlation with this consistent decline in CVP. RESULTS: Neither the absolute CVP nor the drop in CVP appeared to influence the rate of ATN. Interestingly, we found that the kinetics of the decline in CVP were remarkably similar in recipients of both cadaveric and living-related kidneys. CONCLUSIONS: This finding suggests that the reperfusion injury or a related effect may be responsible for the clinical phenomenon presented in this study.

Adult↗

PubMed2002

Immunostimulatory effect of Silybum Marianum (milk thistle) extract.

BACKGROUND: Herbal products are increasingly used for their effects on the immune system. Milk Thistle, a commonly used herbal product is known to inhibit growth of certain tumors, although the mechanism of this effect remains unknown. Previously we have shown that Milk Thistle extracts stimulate neurons in culture. Since other drugs that affect the neuronal; system also affect the immune system, we investigated the effects of Milk Thistle on the immune system. MATERIAL/METHODS: Standardized Milk Thistle extract was studied in murine lymphocyte proliferation tests using Concanavalin A (ConA) as mitogen for non-specific stimulation and mixed lymphocyte culture (MLC) as allospecific stimulation. Th1 and Th2 cytokine levels in MLC were assayed by two antibody capture ELISA technique. All tests were performed in triplicate and repeated twice. RESULTS: We found that Milk Thistle is immunostimulatory in vitro. It increased lymphocyte proliferation in both mitogen and MLC assays. These effects of Milk Thistle were associated with an increase in interferon gamma, interleukin (IL)-4 and IL-10 cytokines in the MLC (table). This immunostimulatory effect increased in response to increasing doses of Milk Thistle. CONCLUSIONS: Our study has uncovered a novel effect of milk thistle on the immune system. This immunostimulatory effect may be of benefit in increasing the immunity to infectious diseases.

Animals↗

PubMedDate not supplied

Value of 2-[18F]-fluoro-2-deoxy-D-glucose imaging with dual-head gamma camera in coincidence mode: comparison with computed tomography/magnetic resonance imaging in patients with suspected recurrent head and neck cancers.

OBJECTIVE: The aim of the present study was to assess the value of dual-head gamma-camera (DHGC) imaging in the coincidence mode using 2-[18F]-fluoro-2-deoxy-D-glucose in differentiating recurrent tumor from posttreatment changes in previously treated head and neck cancer. METHODS: This was a single-center prospective study performed with the approval of our Institutional Review Board. Twenty-nine patients with suspected recurrent head and neck cancers were prospectively enrolled in this study. Dual-head gamma-camera imaging in the coincidence mode followed computed tomography (CT; n = 24)/magnetic resonance imaging (MRI; n = 5) within a period of 1 week (mean = 3.5 days) in all patients. Thirteen patients had definite pathologic confirmation of recurrence by undergoing a biopsy. Sixteen patients, however, did not have a definite pathologic confirmation and were followed clinically. The mean duration of follow-up for the subgroup of patients who were followed clinically was 22.8 months (range: 4-48 months). Sensitivity, specificity, accuracy, positive predictive value (PPV), and negative predictive value (NPV) for CT/MRI and DHGC imaging in the coincidence mode were calculated. RESULTS: The sensitivity, specificity, PPV, NPV, and accuracy of CT/MRI in the detection of recurrent cancer were 76.5%, 58.3%, 72.2%, 63.6%, and 69%, respectively. In contrast, the sensitivity (100%), NPV (100%), and accuracy (82.8%) of DHGC imaging in the coincidence mode were superior to that of CT/MRI. Dual-head gamma-camera imaging in the coincidence mode had a specificity (58.3%) and PPV (77.3%) comparable to those of CT/MRI. CONCLUSION: Our data suggest that modified positron emission tomography with DHGC imaging in the coincidence mode is a useful tool in the assessment of recurrent head and neck cancer.

Adult↗