Gender-Specific Differences in Baseline,Peak, and Delta Serum Creatinine: The NACSELD Experience

Digestive Diseases and Sciences - Women have lower serum creatinine values than men for similar renal function. We aimed to determine the differential effect of baseline, peak, and delta creatinine...     

Electrospun biomimetic nanocomposite nanofibers of hydroxyapatite/chitosan for bone tissue engineering

The development of bioinspired or biomimetic materials is essential and has formed one of the most important paradigms in today's tissue engineering research. This paper reports a novel biomimetic nanocomposite nanofibers of hydroxyapatite/chitosan (HAp/CTS) prepared by combining an in situ co-precipitation synthesis approach with an electrospinning process. A model HAp/CTS nanocomposite with the HAp mass ratio of 30wt% was synthesized through the co-precipitation method so as to attain homogenous dispersion of the spindle-shaped HAp nanoparticles (ca. 100x30nm) within the chitosan matrix. By using a small amount (10wt%) of ultrahigh molecular weight poly(ethylene oxide) (UHMWPEO) as a fiber-forming facilitating additive, continuous HAp/CTS nanofibers with a diameters of 214+/-25nm had been produced successfully and the HAp nanoparticles with some aggregations were incorporated into the electrospun nanofibers. Further SAED and XRD analysis confirmed that the crystalline nature of HAp remains and had survived the acetic acid-dominant solvent system. Biological in vitro cell culture with human fetal osteoblast (hFOB) cells for up to 15 days demonstrated that the incorporation of HAp nanoparticles into chitosan nanofibrous scaffolds led to significant bone formation oriented outcomes compared to that of the pure electrospun CTS scaffolds. The electrospun nanocomposite nanofibers of HAp/CTS, with compositional and structural features close to the natural mineralized nanofibril counterparts, are of potential interest for bone tissue engineering applications.     

Multiple main pancreatic duct stones in tropical pancreatitis: safe clearance with extracorporeal shockwave lithotripsy

BACKGROUND AND AIM: Extracorporeal shockwave lithotripsy (ESWL) has an established role in the management of pancreatic ductal stones. Its efficacy in management of multiple stones in tropical pancreatitis is unknown. The aim of this study was to prospectively evaluate: (i) the efficacy of main pancreatic duct stone clearance; and (ii) associated complications with ESWL therapy in tropical pancreatitis. METHODS: Consecutively recruited patients with tropical pancreatitis underwent fragmentation of main pancreatic duct stones using ESWL. Endoscopic retrograde cholangiopancreatography (ERCP) using standard techniques was performed to manage residual stones. Complete, partial and unsatisfactory clearance was defined as >90%, 50-90% and <50% of stone clearance, respectively. Clinical and technical data were collected on a pre-formatted data sheet. Statistical analysis was performed on an intention-to-treat basis. RESULTS: A total of 250 patients (mean+/-SD age 35.2+/-11.9 years; 66% men), 86.8% with multiple radio-opaque stones, underwent ESWL between February 2004 and May 2005. Of the 250 patients, 149 (59.6%) achieved complete clearance and 59 (23.6%) achieved partial clearance of pancreatic calculi. Main pancreatic ductal decompression was achieved in 70.0% (175/250) of patients. Complications occurred in 5.6% (14/250) during ESWL and in 1.2% (3/250) during ERCP. A mean of 1.3 sessions, with mean+/-SD 5.5+/-0.7 intensity setting, 85.8+/-13.5 pulses per minute and 3862+/-1426 shocks per session were required. CONCLUSION: Clearance of multiple main pancreatic duct stones in patients with tropical pancreatitis is safely performed via ESWL followed by ERCP ductal drainage.     

Electrospun biocomposite nanofibrous scaffolds for neural tissue engineering

Bridging of nerve gaps after injury is a major problem in peripheral nerve regeneration. Considering the potential application of a bio-artificial nerve guide material, polycaprolactone (PCL)/chitosan nanofibrous scaffolds was designed and evaluated in vitro using rat Schwann cells (RT4-D6P2T) for nerve tissue engineering. PCL, chitosan, and PCL/chitosan nanofibers with average fiber diameters of 630, 450, and 190 nm, respectively, were fabricated using an electrospinning process. The surface chemistry of the fabricated nanofibers was determined using Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. Simple blending of PCL with chitosan proved an easy and efficient method for fabricating PCL/chitosan nanofibrous scaffolds, whose surface characteristics proved more hydrophilic than PCL nanofibers. Evaluation of mechanical properties showed that the Young's modulus and strain at break of the electrospun PCL/chitosan nanofibers were better than those of the chitosan nanofibers. Results of cell proliferation studies on nanofibrous scaffolds using 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium assay showed 48% more cell proliferation on PCL/chitosan scaffolds than on PCL scaffolds after 8 days of culture. PCL/chitosan scaffolds showed better cell proliferation than PCL scaffolds and maintained their characteristic cell morphology, with spreading bipolar elongations to the nanofibrous substrates. This electrospun nanofibrous matrix thus proved of specific interest in tissue engineering for peripheral nerve regeneration.     

Evaluation of the Mirasol platelet reduction technology system against Babesia microti in apheresis platelets and plasma

BACKGROUND: Babesia microti is an intraerythrocytic parasite, transmitted naturally to humans by infected ixodid ticks, that causes babesiosis. In recent years, B. microti has been identified as a growing public health concern that has also emerged as a critical blood safety issue in the absence of appropriate interventions to reduce transmission by blood transfusion. Thus, we evaluated the ability of the Mirasol pathogen reduction technology (PRT; CaridianBCT), which uses riboflavin (RB) and ultraviolet (UV) light, to diminish the presence of B. microti in apheresis plasma and platelets (PLTs). STUDY DESIGN AND METHODS: Apheresis plasma and PLT units were spiked with B. microti‐infected hamster blood and subsequently treated using the Mirasol PRT system. Control and experimental samples were collected at different stages during the treatment process and injected into hamsters to detect the presence of viable parasites. Four weeks postinoculation, hamster blood was tested for B. microti infection by blood smear and real‐time polymerase chain reaction analysis. RESULTS: None of the blood smears from animals injected with samples from PRT‐treated plasma or PLT units were positive by microscopy, while all the non–PRT‐treated plasma and PLT units were demonstrably parasitemic. Parasite load reduction in hamsters ranged between 4 and 5 log in all PRT‐treated units compared to untreated controls. CONCLUSION: The data indicate that the use of RB and UV light efficiently reduces the presence of viable B. microti in apheresis plasma and PLT products, thereby reducing the risk of transfusion‐transmitted Babesia potentially associated with these products. Based on this observed “proof of principle,” future studies will determine the efficacy of the Mirasol PRT in whole blood.     

Chylous Ascites Secondary to Pancreatitis: Management of an Uncommon Entity Using Parenteral Nutrition and Octreotide

Malignancy, surgical trauma, cirrhosis and tuberculosis account for more than 95% of causes for chylous ascites. We report a case of persistent chylous ascites following acute pancreatitis that responded to parenteral nutrition and octreotide. A 50 year-old male was diagnosed with acute alcoholic pancreatitis after presenting with typical abdominal pain, and elevated amylase and lipase. The acute symptoms resolved within one week. Four weeks later he started developing increased abdominal girth. Examination revealed the presence of shifting dullness and paracentesis confirmed diagnosis of chylous ascites. Investigations for the common causes of chylous ascites were negative. Laparoscopy confirmed the presence of fat necrosis within mesenteric lymph nodes linking the chylous ascites to the episode of pancreatitis. The Chylous ascites was resistant to the usual medical therapy, but responded only to the combination of octreotide and total parenteral nutrition with complete resolution of ascites in 8 weeks. This case of chylous ascites secondary to pancreatitis represents an uncommon presentation with effective management resulting in a dramatic response.     

Migration is associated with lower total, but not free testosterone levels in South Asian men

OBJECTIVE: Serum testosterone measurement is an integral part of the endocrine assessment of men. Little is known about its variation in relation to migration. We examined within a South Asian group the effect of migration to the UK on androgen levels. DESIGN: Circulating testosterone and SHBG concentrations were measured in 97 Gujarati men resident in India and in 79 men from the same villages of origin living in Birmingham, UK. Free testosterone was calculated by Vermeulen's method. Insulin sensitivity (HOMA-S) was determined from paired fasting plasma intact insulin and glucose values. RESULTS: Circulating testosterone was significantly lower in UK Gujarati men (17.2 nmol/l [15.7-18.7]) vs. Indian Gujarati men (21.7 [20.0-23.5]) (P = 0.0002) (age-adjusted median [95% CI]). There was no difference by migration status in circulating free testosterone. Sex hormone binding globulin (SHBG) levels were lower in UK migrants (16.8 nmol/l [15.5-18.1]) than in nonmigrants (21.9 nmol/l [20.5-23.3]) (P < 0.0001). Testosterone level correlated positively with insulin sensitivity (HOMA-S) (rho 0.16, P = 0.04). In multivariate analysis, total testosterone was independently and positively associated with logSHBG (normalized beta (beta) = 0.29, P = 0.002) and independently and negatively with waist circumference (beta = -0.19, P = 0.04), in a model also including height, age, migration status, leptin and fasting insulin. CONCLUSION: Lower circulating testosterone in UK Gujarati men and its association with markers of insulin sensitivity suggest a profound influence of body composition change with migration on testosterone levels. The lower SHBG in this group restores parity in free testosterone. Account should be taken of SHBG in interpreting testosterone levels in men, as well as in women.