Hepatocellular Carcinoma in Hepatitis B Surface Antigen Carriers in Eight Institutions

We reviewed records of all persons dying between 1979 and 1986 in eight California institutions for the mentally retarded. Autopsies had been done in 71% of the 1,181 deaths. Nine deaths were due to hepatocellular carcinoma, which invariably developed in carriers of hepatitis B surface antigen (HBsAg) and was fatal within four months of diagnosis. The mean age at death was 32.7 years. The incidence of hepatocellular carcinoma in HBsAg carriers was 140 times greater than in the US population. Persistent hepatitis B infection was probably etiologically related to hepatocellular carcinoma in this population, which is relatively free of exposure to other hepatocarcinogens.     

Purification and properties of an extracellular β-glucosidase from the cellulolytic thermophile Clostridium stercorarium

Summary Clostridium stercorarium cultures grown on cellobiose contain both an extracellular and a cell-bound -glucosidase activity. A substantial portion of the cell-bound enzyme could be extracted by osmotic shock, suggesting a periplasmic localization. The -glucosidase present in culture supernatants was purified to homogeneity. It was found to be identical in all aspects tested with the cell-bound -glucosidase. The enzyme exists as a monomer with an apparent molecular weight of 85.000 (SDS-PAGE) and a pI of 4.8. It shows optimal activity as pH 5.5 and 65° C. Thiol groups are essential for enzyme activity. In the presence of reducing agents and divalent cations the half-life of the purified enzyme was more than 5 h at 60°C. The enzyme hydrolyses at different rates a wide range of substrates including aryl--glucosides, cellobiose, and disordered cellulose. K _m values were determined as 0.8 mM for p-nitrophenyl--glucoside (PNPG) and 33 mM for cellobiose. The cellular localization and the substrate specificity pattern are consistent with a dual role of the C. stercorarium -glucosidase in cellulose saccharification: (1) Cleavage of cellobiose formed by exoglucanase and (2) degradation of cellodextrins produced by endoglucanase action.     

Cardiovascular and Pulmonary Effects of a New Sedative/Analgesic (Medetomidine) as a Preanaesthetic Drug in the Dog

Cardiovascular and pulmonary effects of a new sedative/analgesic (medetomidine) as a preanaesthetic drug in the dog. A study was carried out to investigate the possible usefulness of medetomidine (Farmos Group, Turku, Finland) for premedication prior to general anaesthesia with thiopental sodium and halothane. The main emphasis was laid on the circulatory and respiratory effects of medetomidine. Dogs treated with xylazine (2 mg/kg) or placebo (physiological saline solution) served as controls. Medetomidine caused a decrease in blood pressure, heart rate and respiratory rate at all dose levels tested. These decreases were essentially dose -dependent, but there were great individual variations. It is concluded that the drug can be useful for premedication at the lowest dose level tested (10 μ/kg). The sedative effect, however, is so strong that an even lower dose might be sufficient for the present purpose.     

A new experimental approach for the study of cardiopulmonary physiology during early development

In this report, an experimental approach and newly designed apparatus for liquid ventilation of preterm animals are described. Findings of age-related changes in cardiopulmonary function of this animal preparation are presented. Thirty-one lambs, 102-137 days gestation (term 147 +/- 3 days), were studied. The carotid artery, jugular vein, and trachea of the exteriorized fetus were cannulated under local anesthesia. Immediately after cesarean section delivery, ventilation commenced; warmed (39 degrees C) and oxygenated (PIO2 greater than 500 Torr) liquid fluorocarbon (RIMAR 101) was delivered to the lung by a mechanically assisted liquid ventilation system. Skeletal muscle paralysis, low-dose exogenous buffering, and thermal support were maintained during the 3-h experiment. Pulmonary gas exchange, acid-base status, and cardiopulmonary and metabolic function were assessed. By utilizing these techniques, effective arterial oxygenation, CO2 elimination, acid-base status, and cardiovascular stability were supported independent of gestational age. The results demonstrate a developmental increase in specific lung compliance and mean arterial pressure and decrease in heart rate and systemic O2 consumption per kilogram with advancing gestational age. These findings demonstrate that liquid ventilation negates the dependency of effective pulmonary gas exchange on surfactant development, thereby extending the limits of viability of the immature extrauterine lamb. As such this new experimental approach is useful for the study of physiological development over an age range previously limited to fetal animal preparations and, therefore, may provide insight regarding adaptation of the premature to the extrauterine environment.     

Glycosphingolipid expression in spontaneously aborted fetuses and placenta from blood group p women. Evidence for placenta being the primary target for anti-Tja-antibodies

A 12-week-old fetus and one 17-week-old fetus + placenta were obtained after spontaneous abortions from two women of blood group p. The 17-week-old fetus was dissected into intestine, liver, brain and residual tissue. Nonacid glycosphingolipid fractions were prepared from the tissues. Glycolipid characterization was carried out using thin layer chromatography immunostained with monoclonal antibodies and bacteria and by¹H NMR spectroscopy and mass spectrometry. In the placental fraction substantial amounts of globotetraosylceramide (P-antigen) and globotriaosylceramide (P^k-antigen) were identified. In contrast, the fetuses contained only trace amounts of these structures, as revealed by immunostaining. These results indicate that the primary target for the antibodies of the anti-Tj^a serum is the placenta tissue, resulting in termination of the pregnancy.     

Changes in soil microflora associated with control of Sclerotium Rolfsii by Furfuraldehyde

The efficacy of 2‐furfuraldehyde for control of Sclerotium rolfsii was studied in laboratory and greenhouse experiments. Mycelial growth of the fungus was reduced proportionally with concentrations of 0.1–0.5 ml furfuraldehyde l^‐1 agar medium, and viability of sclerotia diminished on exposure to 2‐furfuraldehyde vapours. Detectable populations of bacteria and fungi, including Trichoderma spp., were reduced significantly (9=0.05) when furfuraldehyde was added to the agar used for soil dilution plates of untreated soil. Repeated treatments of natural soil with the fumigant significantly increased populations of Trichoderma spp. and bacteria, but diminished numbers of actinomycetes. Increasing dosages applied to soil artificially infested with S. rolfsii caused a reduction of disease on lentil, Lens culinaris. Results indicate that the compound, when applied to field soil, changes the composition of soil microflora and has potential for integrated control of S. rolfsii.     

A Comparison of the Efficacy of Nuclear Polyhedrosis and Granulosis Viruses in Spray and Bait Formulations for the Control of Agrotis segetum (Lepidoptera: Noctuidae) in Maize

Agrotis segetum nuclear polyhedrosis virus (AsNPV) and granulosis virus (AsGV), propagated in laboratory cultures of A. segetum in England and A. ipsilon in Spain, respectively, were applied to plots of maize plants at the one‐ to four‐leaf stage of growth. Plots were arranged in a 6 x 6 Latin square design and infested with second‐instar A. segetum larvae (the common cutworm). Each virus was applied in separate treatments by two application methods; as an aqueous spray containing 0.1% Agral as a wetting agent, and as a bran bait. The NPV was applied at a rate of 4 X 10¹² polyhedra/ha, and the GV at 4 X 10¹³ granules/ha. Soil and plants were sampled for larvae on three occasions following virus treatment: 24 h, 4 days and 11 days. The larvae were reared on diet in the laboratory, until death or pupation, to examine the rate and level of viral infection. Infection data showed 87.5% and 91% NPV infection and 12.5% and 55% GV infection in spray and bait treatments, respectively, in larvae sampled 24 h after treatment. In larvae sampled 4 days after treatment, the results were 78% and 100% NPV infection, and 13% and 6% GV infection. A total of only six larvae were retrieved on day 11. In both treatments larvae infected with AsNPV died significantly more rapidly and at an earlier instar than those infected with AsGV, indicating that AsNPV appears to have better potential as a control agent for A. segetum.     

Human pheochromocytoma cells studied in culture contain large amounts of DSIP-like material.

Delta sleep-inducing peptide (DSIP)-like immunoreactive (LI) material has been detected in nine different human pheochromocytoma tumors by immunocytochemistry. In primary tumors subjected to indirect immunofluorescence a variable number of tumor cells (25-75%) showed positive cytoplasmic labeling after incubation with DSIP antiserum. Tumor cells grown in culture were strongly labeled by the DSIP antiserum with DSIP-LI concentrated to cell bodies. Electron microscopic immunocytochemistry (immunogold labeling) of pheochromocytoma cells demonstrated DSIP-LI over the dense core of secretory granules. The presence of DSIP-LI in several HPLC fractions from conditioned culture media indicates secretion of DSIP-LI from cultured pheochromocytoma cells. The observations suggest that DSIP-LI is synthesized and stored in secretory granules before release. The different HPLC profiles from each of the tumors may reflect differences in processing or turnover of DSIP-LI in pheochromocytoma cells.     

Autonomous DNA replication in human cells is affected by the size and the source of the DNA.

We previously developed short-term and long-term assays for autonomous replication of DNA in human cells. This study addresses the requirements for replication in these assays. Sixty-two random human genomic fragments ranging in size from 1 to 21 kb were cloned in a prokaryotic vector and tested for their replication ability in the short-term assay. We found a positive correlation between replication strength and fragment length, indicating that large size is favored for efficient autonomous replication in human cells. All large fragments replicated efficiently, suggesting that signals which can direct the initiation of DNA replication in human cells are either very abundant or have a low degree of sequence specificity. Similar results were obtained in the long-term assay. We also used the same assays to test in human cells a random series of fragments derived from Escherichia coli chromosomal DNA. The bacterial fragments supported replication less efficiently than the human fragments in the short-term and long-term assays. This result suggests that while the sequence signals involved in replication in human cells are found frequently in human DNA, they are uncommon in bacterial DNA.