Extension of the Pre-rigor Period in Ischemic White Muscle from Yellow-eye Mullet Aldrichetta forsteri) and New Zealand Snapper (Pagrus auratus) as Affected by Hyperbaric Oxygen Treatment

ABSTRACT: Chemical anesthesia (AQUI-STM Plus) was used to harvest tank-rested yellow-eye mullet ( Aldrichetta forsteri ) and snapper ( Pagrus auratus ) in a "rested" state. Fillets were stored at half the acclimated temperature under hyperbaric, hyperoxic conditions and compared with fillets stored under normobaric, hyperoxic conditions. Postmortem (PM) changes in white muscle (WM) cut-surface pH and key metabolites (lactate, adenosine triphosphate [ATP], and inorganic phosphate [P i ]) were measured. Hyperbaric, hyperoxic storage extended the pre-rigor period in the rested WM by delaying PM changes. Prolongation of pre-rigor was greatest in rested snapper WM. This was attributed to an extended period of aerobic metabolism in PM rested WM.     

Acute neutropenia decreases inflammation associated with murine vaginal candidiasis but has no effect on the course of infection

We have used a mouse model of vaginal candidiasis to determine the effect of neutrophil depletion on (a) the clearance of Candida albicans and (b) the degree of inflammation associated with infection. No differences in recoverable yeast number or rate of clearance were observed between normal and neutrophil-depleted mice; however, vaginal inflammation was significantly decreased in neutrophil-depleted animals.     

Quantitative gated blood pool SPECT for the assessment of coronary artery disease at rest

Renal involvement is rare in chronic active Epstein-Barr (EB) virus infection. We report a case of a 7-year-old girl with recurrent EB virus infection. She had fever, lymphadenopathy, hepatosplenomegaly, and persistently high titres of IgG to EB virus capsid antigen (VCA) and IgG to EB early antigen with low titres of IgM to VCA. She showed mild haematuria and proteinuria, but had no symptoms of renal failure. Renal biopsy revealed immune complex-mediated glomerulonephritis, which may have been due to a persistently high titre of antibody against EB virus. In addition, a peculiar form of tubulointerstitial nephritis was found. The morphology was characterized by a papillary infolding of the tubular epithelial cell layer into the tubular lumen. The interstitium was surrounded by the infolded epithelium and contained a large number of B-cell dominant lymphocytes. EBV-encoded RNA 1 (EBER-1) gene was detected in the nuclei of some tubuloepithelial cells by in situ hybridization and may have been associated with the pathogenesis of tubulointerstitial nephritis.     

Factorial trial of three interventions to reduce the progression of precancerous gastric lesions in Shandong, China: design issues and initial data

In the fall of 1995, 3411 subjects in 13 rural villages in Linqu County, Shandong Province, China, began participating in a blinded, randomized 23 factorial trial to determine whether interventions can reduce the prevalence of dysplasia and other precancerous gastric lesions. One intervention is treatment for infection by Helicobacter pylori with amoxicillin and omeprazole. A second is dietary supplementation with capsules containing vitamin C, vitamin E, and selenium. A third is dietary supplementation with capsules containing steam-distilled garlic oil and Kyolic aged garlic extract. Investigators will evaluate histopathologic endpoints after gastroscopies with biopsies from seven standard sites in 1999. Initial data from pill counts and sampled blood levels of vitamin E, vitamin C, and S-allylcysteine indicate excellent compliance. Subjects have tolerated all interventions well, although 3.1% of those assigned to amoxicillin and omeprazole developed rashes, compared to 0.3% to those in the control group. Preliminary breath tests demonstrate substantial reductions in gastric urease activity, an indication of infection by Helicobacter pylori, among those assigned to amoxicillin and omeprazole.     

CD95 (APO-1/Fas) mutations in childhood T-lineage acute lymphoblastic leukemia

CD95 (APO-1/Fas)-mediated apoptosis is pivotal in normal lymphocyte homeostasis and mutations of CD95 cause a benign autoimmune lymphoproliferation syndrome (ALPS) in humans and mice. However, tumors only rarely develop in these patients, and no CD95 mutations have yet been directly implicated in tumorigenesis. We therefore examined 81 de novo childhood T-lineage acute lymphoblastic leukemias (T-ALL) including 54 steroid-poor responders, 10 relapsed T-ALL, and 10 leukemic T-cell lines, for the presence of CD95 mutations using single-strand confirmation polymorphism and sequence analysis. In leukemic blasts and normal T cells of one patient, a heterozygous mutation in exon 3 of CD95 causing a 68Pro --> 68Leu change associated with decreased CD95-mediated apoptosis was found. In leukemic blasts and normal T cells of a second patient, a homozygous mutation in the promoter of CD95 causing disruption of a consensus sequence for AP-2 binding without decreasing constitutive CD95 expression was detected. No large intragenic alterations of CD95 were found, no homozygous loss was detected in the cell lines, and no CD95 mutations were detected in the relapses. The data presented here show that CD95 mutations occur in some T-ALL and may be of biological importance.     

CD45RA(bright)/CD11a(bright) CD8+ T cells: effector T cells

An important aspect of peripheral T cell development is the differentiation from naive into memory cells. To distinguish naive from memory cells, CD45RA and CD11a are commonly used: CD45RA+ or CD11a(dim) T cells are regarded as naive, while CD45RA- or CD11a(bright) T cells are thought to be of memory type. There is, however, a CD8+ T cell subset which is CD45RA+ and at the same time CD11a(bright). It increases with age and in patients with systemic viral infections, though its functional role in the immune response is unknown. In the present study, we give evidence that this subset is related to memory-like T cells as it produces IFN-gamma and tumor necrosis factor-alpha, contains high levels of perforin, and expresses CD95 in the same way as memory-type CD45RA-/CD11a(bright) CD8+ T cells. Since it contains a high percentage of CD28- and CD57+ cells, is increased in size and granularity, and is transiently expressed following in vitro stimulation of naive CD8+ T cells, we speculate that this subset mainly represents recently activated effector T cells that are able to interact with CD80 and CD86 (B7-1 and B7-2 respectively) negative tissue cells.     

Enzyme mediated C-C bond formation

Most publications devoted to diagnosis of helminths emphasize characteristic parasitological features. Histological feature are seldom described in detail. The purpose of this study was to propose a diagnostic method suitable for use by histologists who, unlike parasitologists, do not visualize the whole worm but rather pieces randomly scattered over a slide. It is relatively easy to distinguish helminths which have smooth muscle, no respiratory or circulatory system, and no coelom from arthropods which have striated muscle, both respiratory and circulatory systems, and coelom. At the adult stage, roundworms or nemathelminths present an external cuticle that may have patterned markings. The visceral cavity is empty. Adults can dwell either in the intestine in which case they are oviparous (oxyuris, ascaris, Ancylostoma, Strongyloides stercoralis, Trichuris...) or in tissue in which case they are viviparous (filaria). Larva of some species can be found in tissues. Adult tape-worms are devoid of cuticle and have a mesenchymatous visceral cavity. Cestodes which are segmented and have no digestive tract (taenias) are readily distinguishable from trematodes which are not segmented and have a digestive tract (faciolasis) Some cestodes unable thrive in man can cause cyst formation (hydatidosis, sparganosis, cysticercosis, coenurosis). On the basis of symptoms and histological features, it is usually possible to diagnose the genus and even the species of the offending helminth provided that the parasite has not been excessively damaged and that a sufficient number of sections are available.     

Differential activation by xenoestrogens of ER alpha and ER beta when linked to different response elements

The discovery of a second estrogen receptor (ER beta) has significant implications for our understanding of the molecular basis for the diverse actions of estrogen. Here we report the differential activation by natural and xenobiotic estrogens of ER alpha and ER beta when linked to different response elements. Receptor mediated activation of reporter constructs containing either the estrogen response element (ERE) from the vitellogenin (Vit) gene or from the luteinizing hormone beta (LH) gene were examined in transiently transfected Cos-1 cells. ER beta preferentially activated the consensus Vit ERE whereas ER alpha showed greater activation at the divergent LH ERE. This differential activation was observed for a number of ligands including estradiol, estrone, bisphenol A, octylphenol and diethystilbestrol. These findings show that the nature of the ERE, as well as the ratio of ER subtypes in a particular cell/tissue, will influence whether particular estrogen responsive genes are activated in the presence of natural or xenobiotic estrogens.     

Wound healing: a paradigm for lumen narrowing after arterial reconstruction

PURPOSE: The intimal hyperplasia hypothesis that equates lumen narrowing after arterial injury with intimal mass has recently been challenged. Evidence has emerged to suggest that lumen narrowing is caused in large part by changes in artery wall geometry rather than intimal mass per se. We have begun to explore this hypothesis in a unique nonhuman primate model of atherosclerosis. METHODS: Monkeys who were fed an atherogenic diet for 3 to 5 years underwent experimental angioplasty of the left iliac artery. The contralateral iliac artery served as an intraanimal control. Arteries were removed 2, 4, 7, 14, 28, or 112 days later for analysis (6 or 13 per time point). Angioplasty dilated arteries by fracturing atheroma and stretching or tearing the media. Cross-sections of injured arteries were analyzed for expression of extracellular matrix components and cell surface integrins that are important in wound healing. Antibodies, riboprobes, or histochemical stains specific for fibrin, hyaluronan, versican (chondroitin sulfate-containing proteoglycan), procollagen-I, elastin, and the alpha 2 beta 1 and alpha V beta 3 integrins were used. RESULTS: A thin mural thrombus was seen at sites of denudation and plaque fracture (days 2 to 7). This provisional matrix was invaded by leukocytes (days 2 to 4) and alpha-actin-positive smooth muscle cells (SMCs; days 4 to 7). Thrombus was replaced by SMCs expressing hyaluronan and the associated versican proteoglycans (day 14). Versican was expressed throughout the neointima as it enlarged (day 28), but expression later subsided (day 112). Procollagen-I expression initially increased in the adventitia (day 4) and then in the forming neointima (day 14). Procollagen-I expression was found to persist within the adventitia and in the neointima in SMCs nearest the lumen (days 28 to 112). Elastin staining was prominent within the mature neointima (day 112) but not at earlier time points. Integrin expression also increased within the injured artery wall. alpha v beta 3 staining (fibrin[ogen] receptor) increased in the injured media (days 2 to 7) and was then seen throughout the early neointima (day 7). Low level expression of alpha V beta 3 subsequently persisted within the forming neointima (day 28). alpha 2 beta 1 (collagen receptor) expression increased in the neointima in SMCs nearest the lumen (day 28). CONCLUSIONS: Lumen narrowing after angioplasty in this model of atherosclerosis is caused largely by decreased artery wall diameter. The pattern of matrix and integrin expression within the injured artery wall is in many ways analogous to that of healing wounds. These observations suggest that tissue contraction may play a role in lumen narrowing at sites of arterial reconstruction. Strategies to inhibit wound contraction may prove effective in preventing restenosis.