APOE in non-Alzheimer amyloidoses: transmissible spongiform encephalopathies

We have identified a member of the VEGF family by computer-based homology searching and have designated it VEGF-D. VEGF-D is most closely related to VEGF-C by virtue of the presence of N- and C-terminal extensions that are not found in other VEGF family members. In adult human tissues, VEGF-D mRNA is most abundant in heart, lung, skeletal muscle, colon, and small intestine. Analyses of VEGF-D receptor specificity revealed that VEGF-D is a ligand for both VEGF receptors (VEGFRs) VEGFR-2 (Flk1) and VEGFR-3 (Flt4) and can activate these receptors. However. VEGF-D does not bind to VEGFR-1. Expression of a truncated derivative of VEGF-D demonstrated that the receptor-binding capacities reside in the portion of the molecule that is most closely related in primary structure to other VEGF family members and that corresponds to the mature form of VEGF-C. In addition, VEGF-D is a mitogen for endothelial cells. The structural and functional similarities between VEGF-D and VEGF-C define a subfamily of the VEGFs.     

Secondary membranoproliferative glomerulonephritis due to hemolytic uremic syndrome: an unusual presentation

In vitro selection can be used to generate nucleic acid ligands (aptamers) to target molecules ranging in size and structure from cations to cells. However, the selection process is repetitive and time-consuming. We have automated a protocol for in vitro selection using an augmented Beckman Biomek 2000 pipetting robot. The automated selection procedure requires the integration of four devices and the optimization of four molecular biology methods, and is one of the most complex automated protocols attempted to date. Initial attempts at selection yielded robust replication parasites, but optimization of the automated selection procedure suppressed the emergence of these parasites and led to the selection of true nucleic acid ligands. Automated selection can now be used to generate nucleic acid aptamers in days rather than weeks or months.     

Prognostic significance of allelic losses in primary melanoma

Loss of genetic material, including loss of loci on chromosome arms 6q, 9p, and 10q, occurs frequently in cutaneous melanoma but infrequently in benign melanocytic nevi or other melanocytic lesions, suggesting that these genetic alterations are important in the development and progression of melanoma. To examine whether allelic loss is of prognostic importance in melanoma, disease-free survival was related to loss of heterozygosity on 6q, 9p and 10q in 83 individuals with sporadic primary cutaneous melanoma. Loss of chromosome arms 6q and 10q were each significantly associated with a poorer clinical outcome (P=0.013 and P=0.001 respectively). In a subgroup of 41 subjects whose primary tumours were allelotyped, the fractional allelic loss (FAL) at 39 autosomal arms also significantly correlated with disease-free survival (P=0.013), with an increase in FAL associated with a poorer outcome; this association remained significant when controlled for tumour thickness (P=0.035). In addition, a greater proportion of cells were immunopositive for Ki67 antigen, p53 and p21WAF1 protein in the primary melanomas than in the benign melanocytic nevi, however, only p53 over-expression was significantly associated with improved survival (P=0.041).     

Influence of the affinity of selecting ligands on T cell positive and negative selection and the functional maturity of the positively selected T cells

Interaction of the TCR on immature thymocytes with ligands on antigen presenting cells can lead to different fates including positive and negative selection. The affinity of the selecting ligands plays an important role in determining these outcomes. We used the 2C TCR transgenic model to evaluate the efficacy of ligands with widely differing affinity (3 x 10(3) - 2 x 10(6) M-1) for the 2C TCR in mediating thymic negative and positive selection. Our results support the conclusions that the deletion of immature thymocytes is not only mediated by high-affinity ligands but also by low-affinity/avidity ligands. However, high- and low-affinity ligands differ in their requirements for negative selection. We also present evidence that positive selection is not an all or none process but depending on the strength of interaction between the ligand and the TCR during the positive selection process can result in single positive thymocytes that are at different stages of functional maturity.     

Syntenic assignment of dopamine tautomerase (DCT) to bovine chromosome 12

Heterologous primers were used to amplify an exon and intron-containing segment of the bovine homologue of the human dopachrome tautomerase gene. After confirmation of homology by sequence analysis (exon sequence similarity greater than 90%), bovine-specific primers were developed for synteny mapping purposes. The dopachrome tautomerase gene was assigned to bovine chromosome 12 (BTA12) with 97% concordance to the coagulation factor 10 locus. Together with previous synteny mapping of bovine chromosome 12 genes, fms-related tyrosine kinase, esterase D and 5-hydroxytryptamine receptor 2, this assignment further indicates conservation between human chromosome 13q and bovine chromosome 12.     

Abdominal trauma and pelvic injury in the growth period

Children with pelvic fractures usually are polytraumatized. Concomitant abdominal and pelvic injuries are not uncommon. Medical records and X-rays of 54 children, in which a pelvic fracture was diagnosed at our institution from 1974-1993, were reviewed. Children ages < or = 16 years and treated as in-patients were included in this study. The fractures were classified according to the AO-Classification. 47 patients (87.0%) had concomitant injuries. The mean Polytrauma Score was 23.7 (mean Injury Severity Score 30.5). Nine Children sustained an open pelvic fracture with rectal and/or vaginal tear. 15 genitourinary lesions were found in 13 children. 18 patients underwent laparotomy. A large pelvic/retroperitoneal hematoma was found in 11 cases. There were 7 liver lacerations, 7 splenic injuries, 2 mesenteric tears, 2 kidney injuries and 1 small bowel lesion. Eight children (14.8%) died with 5 of them due to retroperitoneal or/and abdominal bleeding complications. A recent follow-up examination (81.8%) with a mean follow-up of 11.3 years showed that long-term morbidity usually was attributed to pelvic concomitant injuries.     

Dependence of the driving force of the sodium pump on rate of transport

The driving force for active transport of Na+ in the isolated toad bladder, ENa, was measured as the reciprocal slope of the change in conductance with change in short-circuit current after stimulation with antidiuretic hormone. The base-line short-circuit current was altered by change in ambient Na+ concentration or addition of amiloride, maneuvers which alter availability of Na+ at the site of active transport. In the absence of a chemical gradient for Na+ across the bladder, ENa was found to be inversely related to the rate of Na+ transport, a finding incompatible with the simple electrical analogue that has been proposed for the system. The results provide additional support for the view that ENa measured in this way has both energetic and kinetic components.     

Ultrasound findings in hepatitis

A retrospective study of ultrasound images of the liver in patients with hepatitis was undertaken. Two distinct ultrasound patterns were detected. In acute hepatitis, the predominant findings were accentuated brightness and more extensive demonstration of the portal vein radicle walls and overall decreased echogenicity of the liver. Chronic hepatitis primarily revealed decreased brightness and number of portal vein radicle walls and verall increased liver echogenicity. In addition, the pathological severity closely paralleled these ultrasound patterns. A prospective study confirmed the same acute hepatitis ultrasound findings with close correlation to the clinical severity. These distinct ultrasound patterns will help to evaluate patients with suspected acute and chronic hepatitis and more accurately define intrahepatic causes of jaundice.     

The comparative histopathology of primary and secondary lesions in murine salmonellosis

In a primary infection, Swiss-Webster mice were injected i.p. with 10(2) or 10(3) virulent Salmonella typhimurium. Multiple microscopic acute abscesses with predominantly polymorphonuclear leucocytes (PMNs) were seen in the liver and the spleen beginning on the 4th day after infection. By the 7th day, these lesions had become enlarged and were gradually transformed into granulomas with central necrosis and peripheral mononuclear cells. The animals usually died within 12 days with massive systemic infection and degeneration of the tissues. In contrast, it was necessary to inoculate 10(6) virulent salmonella i.v. into mice immunized with avirulent S. thphimurium in order to initiate microscopically observable lesions in the liver and the spleen. These secondary lesions were characterized by the early appearance of minute granulomas composed almost entirely of histiocytic cells. They remained small and isolated, usually without central necrosis. Subsequent regression of the lesions and regeneration of normal tissue occurred after the 2nd week following infection. The animals usually survived such a challenge infection.     

Pharmacokinetics and metabolic disposition of 14C-metronidazole-derived radioactivity in rat after intravenous and intravaginal administration

Urinary metabolites and the pharmacokinetics of radioactivity derived from 14C-metronidazole (14C-MTZ) were determined after intravenous (iv) or intravaginal (ivg) administration of 10 mg/kg to adult rats. Following iv or ivg administration, the disappearance of 14C from blood followed the kinetics of a two-compartment open-system model. The blood half-lives of 14C during the beta-phase were 10.9 +/- 1.6 and 13.6 +/- 4.2 hr, after iv and ivg administration, respectively. After ivg application, the MTZ-derived radioactivity was detected in tail blood at 5 min, peaked at 1 hr, declined rapidly to 6 hr and more slowly thereafter. The vaginal absorption half-life of 14C-MTZ was 0.28 +/- 0.09 hr. About 12% of the administered dose remained in the vagina after 1 hr and 1.5% after 24 hr. At 24 hr, the tissue distribution and concentration of 14C were similar in iv and ivg dosed rats, the highest 14C concentration being present in the kidneys and lowest in the fat. The percentages of the dose excreted in 24 hr in the urine and feces were 58 and 15 after iv administration, compared to 37 and 40 after the ivg route, respectively. Unchanged 14C-MTZ and five of its metabolites were detected in the urine irrespective of the route of administration. The results show that metronidazole is rapidly absorbed through the vaginal mucosa of the rat and the metabolism and excretion of this chemotherapeutic agent are influenced by the route of administration.