Hyperemic Islets: A Possible Explanation for Poor Yields in Human and Porcine Islet Isolation

When studying histological characteristics of human and porcine pancreata in relation to islet isolation, we encountered a remarkably high number of hyperemic islets. The abnormalities observed in these islets ranged from a single dilated vessel through multiple widely dilated vessels to hemorrhages extending into the surrounding exocrine tissue. We determined their possible relevance for outcomes of islet isolation. This study involved a histological examination of 143 porcine pancreata (72 juvenile and 71 adult) and islet isolation from 48 adult pancreata. Human pancreata obtained from 71 multiple organ donors yielded islet isolation in 24 cases. To determine their endocrine content, tissue samples were stained with Aldehyde Fuchsin. The presence of hyperemic islets was scored semiquantitatively with pancreata allotted to categories based on the severity. In humans and pigs we observed hyperemic islets in 48% of pancreata, but only 4.0 ± 2.4% of the islets were hyperemic. In both humans and pigs, significantly higher endocrine content was found in the most severely affected pancreata. When the higher endocrine content was taken into account and isolation results were expressed as ratios of yield and content, we observed significantly lower yields in the most affected pancreata in pigs with a trend toward lower yields in humans. A substantial proportion of human and porcine pancreata contain hyperemic islets. Although the results in humans are preliminary, our data suggest that this phenomenon may contribute to the unpredictable, highly variable islet yields in pigs and humans.     

应用低严格度—单引物聚合酶链反应对问号钩体中国参考株的…

Ｇ１、Ｇ２引物是对问号钩体具有特异性引物。分别用Ｇ１或Ｇ２单引物对问号钩体中国参考株进行前４个低严格度循环的ＰＣＲ扩增，扩增带谱显示赖型、犬型、致热型、秋季型、澳洲型、临海型、乌尔夫型、溶血型为一类，而爪哇型、拜伦型、波摩那型、七日热型、巴叶赞型塔拉索夫型、曼耗Ⅱ型是不与以上赖型等血清型本为一类，双曲钩体ａｔｏｃ型及伊利尼细丝体伊利尼型的扩增带谱与问号钩体截然不同。应用苯酚法提取的高纯度钩体ＤＮＡ     

Increased tissue-type plasminogen activator activity in orthotopic but not heterotopic liver transplantation: the role of the anhepatic period.

The major cause of the increased tissue-type plasminogen activator activity during orthotopic liver transplantation is still unclear. Both the lack of hepatic clearance of tissue-type plasminogen activator in the anhepatic period and increased endothelial release from the graft on reperfusion have been proposed as the major causes. Heterotopic liver transplantation avoids the resection of the host liver and is a useful model to help differentiate between these two possibilities. In this study the fibrinolytic system was evaluated in 10 orthotopic liver transplantations, 18 heterotopic liver transplantations and a control group of 10 partial hepatic resections. A marked increment in tissue-type plasminogen activator activity, from 0.2 to 5.2 IU/ml (p less than 0.02), was observed during the anhepatic period of orthotopic liver transplantation, which rapidly normalized after reperfusion. In contrast, tissue-type plasminogen activator activity levels remained normal in heterotopic liver transplantation and partial hepatic resections. In orthotopic liver transplantation and in heterotopic liver transplantation no increase occurred in tissue-type plasminogen activator activity after reperfusion. The first venous hepatic outflow after reperfusion did not contain elevated tissue-type plasminogen activator activity levels. Plasma degradation products of fibrin and fibrinogen increased during the anhepatic period of orthotopic liver transplantation (from 2.60 to 8.80 micrograms/ml [p less than 0.008] and from 0.40 to 1.60 micrograms/ml [p less than 0.04], respectively) and remained elevated thereafter. In heterotopic liver transplantation and partial hepatic resections these levels remained low. In conclusion, the lack of hepatic clearance during the anhepatic period is probably the most important factor in the evolution of increased tissue-type plasminogen activator activity during orthotopic liver transplantation.     

Detection of leptospiral DNA by nucleic acid hybridisation with 32P- and biotin-labelled probes

Dot hybridisation with 32P- and biotin-labelled probes prepared from leptospiral DNA was performed to develop a sensitive and specific diagnostic method for early infection with leptospires. The smallest amounts of leptospiral DNA that could be detected with 32P- and biotin-labelled probes was 1.5 pg and 5 pg, respectively, corresponding to about 750 and 2500 leptospires. Dot hybridisation with a 32P-labelled probe detected leptospiral DNA in sera from all of 14 experimentally infected golden hamsters. The smallest amount of leptospiral DNA detected in these experiments corresponded to about 2500 leptospires. In the test conditions described in this study, the sensitivity of dot hybridisation with a biotin-labelled probe was lower. Little cross-hybridisation was observed with unrelated DNAs which indicates that dot hybridisation could be a useful diagnostic method.     

Electromagnetic shock wave lithotripsy of gallbladder stones in vitro: the role of different stone characteristics and treatment variables

From 40 sets of five human gallstones obtained at cholecystectomy, four stones were subjected to either 125/250 (maximum generator output) or 250/500 (half maximum generator output) electromagnetic shock waves (treatments I/II and III/IV, respectively); the fifth stone was used for computed tomography (CT) and chemical analysis. Overall, 130 (81%) of 160 stones fragmented, including 72 (45%) adequately (fragments less than or equal to 5 mm). For the treatments I, II, III, and IV the overall fragmentation rates were 80%, 95%, 70%, and 80%, respectively. The corresponding percentages of adequate fragmentation ( less than or equal to 5 mm) were 38%, 70%, 30%, and 42%, respectively. The best results were thus obtained after application of 250 shock waves (maximum generator output; treatment II). Pure cholesterol stones (p less than 0.01), stones with a mean CT density less than or equal to 110 HU (p less than 0.001), and stones with a calcified rim (p < 0.05) fragmented significantly better, but adequate fragmentation ( less than or equal to 5 mm) was significantly determined by stone weight and diameter (p less than 0.001), bilirubin content (p less than 0.02), and calcium content (p less than 0.05). A weight greater than 500 mg and a diameter > 10 mm could be defined as stone characteristics with significant negative predictors of adequate fragmentation. However, because the experimental conditions in this in vitro study did not completely simulate clinical settings for various reasons, these observations must be interpreted accordingly.(ABSTRACT TRUNCATED AT 250 WORDS)     

Small supplements of N-3 fatty acids change serum low density lipoprotein composition by decreasing phospholipid and apolipoprotein B concentrations in young adult women

Summary In order to investigate the effect of a short-term application of marine n-3 polyunsaturated fatty acids on the composition of serum very low density lipoproteins (VLDL), low density lipoproteins (LDL), and high density lipoproteins (HDL), nine women aged 29±4.2 years, following a diet with a SFA/MUFA/PUFA profile of 2.4/3/1, received supplements of six capsules daily, each capsule containing 0.137 g of n-3 fatty acids (14.5% eicosapentaenoic acid (EPA) and 8.9% docosahexaenoic acid (DHA)) for 10 d. Food consumption, assessed during two 10-days periods indicates that percentage contribution of SFA, MUFA, and PUFA to the daily energy intake did not change through the fish-oil supplementation period, but the daily consumption of n-3 fatty acids increased 2.3 times. N-3 fatty supplementation increased EPA and DHA percentages in serum phospholipids, but failed to decrease (p>0.05) the cholesterol and triglyceride concentration in serum LDL and HDL, although it did so in VLDL. In contrast, the lipoprotein-phospholipid and lipoprotein-protein concentrations were markedly affected, mainly in LDL and HDL (at least p<0.01). HDL and VLDL compositions were not affected but the total mass (lipid+protein in mg/dl) concentration of these lipoproteins significantly decreased (p<0.05), suggesting a lower number of these particles in circulating blood after the n-3 treatment. The LDL-cholesterol/LDL-apolipoprotein B ratio increased (p<0.01) reflecting a probable increase in LDL size. Following fish oil supplementation, LDL particles contained a significantly lower amount of phospholipids, which also suggests changes in the surface/core ratio of the average LDL. Changes in serum lipoprotein lipids did not significantly correlate with any dietary change other than the n-3 fatty acid increase. The results indicate that a 10-day application of a small supplement of n-3 change the LDL composition leading to less atherogenic LDL particles with lower phospholipid and apolipoprotein (Apo) B concentrations. Received: 15 May 1998, Accepted: 28 August 1998     

Rapid emergence of resistant coagulase-negative staphylococci on the skin after antibiotic prophylaxis

One approach for prosthetic vascular surgery is to continue antimicrobial prophylaxis while intravascular lines and catheters are in place. However this may give rise to antimicrobial resistance in the colonizing bacterial flora. We studied 37 patients undergoing vascular surgery, who received either co-amoxyclav for three days (group 1), ofloxacin plus metronidazole for three days (group 2) or for one day (group 3), respectively. Seventeen hospitalized patients not undergoing surgery or receiving antibiotics were studied as controls. In groups I and II there was a significant decline in susceptibility to cloxacillin (12.8% respectively 23.6%) and ofloxacin (0.5% and 85% respectively) in skin staphylococci. The results from group 3 were intermediate. Molecular typing showed that the patient's susceptible community-derived strains were replaced by genetically unrelated resistant strains, probably hospital derived. Long-term prophylaxis should be avoided as colonization occurs with resistant strains.