Regulation of synoviocyte proliferation, apoptosis, and invasion by the p53 tumor suppressor gene.

Recent studies show that 1) the p53 tumor suppressor protein is overexpressed by rheumatoid arthritis (RA) synovium and fibroblast-like synoviocytes (FLS) and 2) somatic mutations previously identified in human tumors are present in RA synovium and FLS. We have hypothesized that abnormalities in p53 can contribute to chronic destructive RA synovitis. To understand the functional consequences of p53 abnormalities in FLS, RA and normal FLS expressing wild-type p53 were transduced with a retroviral vector encoding the human papilloma virus 18 E6 gene, which inactivates endogenous p53 protein. Three RA and one normal FLS lines were infected with recombinant retrovirus encoding the neomycin resistance gene (neo) or E6+neo. FLS proliferation, apoptosis, and invasion was studied in E6, neo, and uninfected parental strains (PS). The growth rate for E6 was significantly increased with a sixfold increase in cell number after 7 days compared with a twofold to threefold increase in neo and PS. When FLS were treated with cytokines, proliferative response of E6, neo, and PS to interleukin-1 and transforming growth factor-beta were similar. However, response to platelet-derived growth factor was significantly greater in E6 FLS compared with neo or PS. Apoptosis was studied by incubating FLS with sodium nitroprusside as a source of nitric oxide or hydrogen peroxide for 8 hours and examining DNA fragmentation and E6 cells were significantly less susceptible to cell death. In addition, E6 FLS were more invasive into cartilage extracts than neo or PS using an in vitro cell invasion assay. These data suggest that p53 is a critical regulator of FLS proliferation, apoptosis, and invasiveness. Abnormalities of p53 function might contribute to synovial lining expansion and joint destruction in RA.     

Acute bacterial endocarditis due to Hemophilus parainfluenzae. Response to ceftizoxime in an ampicillin-allergic patient

Endocarditis secondary to Hemophilus parainfluenzae is an uncommon entity that appears to be increasing in frequency, perhaps due to improved laboratory isolation techniques. Although controversial, most of the published literature recommends a penicillin, with or without concomitant gentamicin, as definitive therapy. We report the first successful use of the third-generation cephalosporin ceftizoxime in an ampicillin-allergic patient. A 55-year-old white female was hospitalized after 5 days of experiencing fever, chills, nausea, and vomiting. A cardiac echocardiogram revealed a large mitral valve vegetation, and the patient was treated with intravenous ampicillin, gentamicin, and clindamycin. Two weeks after emergency mitral valve replacement the patient developed spiking fevers and a macular, erythematous rash while receiving ampicillin. Ceftizoxime was initiated and continued to complete a 4-week period of intravenous antibiotics. Follow-up at 14 months showed no further evidence of infection. Ceftizoxime appears efficacious in eradicating H. parainfluenzae in patients allergic to penicillin.     

The effect of desmopressin on nocturnal polyuria, overnight weight loss, and morning postural hypotension in patients with autonomic failure

Day and night urine volume, morning and evening body weight, and supine and sitting blood pressure were measured in five patients with chronic autonomic failure who were not receiving treatment with drugs. All had nocturnal polyuria, overnight weight loss, and a pronounced postural fall in blood pressure, with lowest levels in the morning. Desmopressin (2-4 micrograms given intramuscularly at 8 pm) reduced nocturnal polyuria, diminished overnight weight loss, raised supine blood pressure, and reduced the postural fall, especially in the morning, when patients were often at their worst. Desmopressin may be a useful alternative to, or may supplement, other forms of treatment in some patients with autonomic failure.     

-2-Hydroxyglutaric acid inhibits mitochondrial creatine kinase activity from cerebellum of developing rats

L-2-Hydroxyglutaric acid (LGA) is the biochemical hallmark of patients affected by the neurometabolic disorder known as L-2-hydroxyglutaric aciduria (LHGA). Although this disorder is predominantly characterized by severe neurological findings and pronounced cerebellum atrophy, the neurotoxic mechanisms of brain injury are virtually unknown. In the present study, we investigated the effect of LGA, at 0.25-5mM concentrations, on total creatine kinase (tCK) activity from cerebellum, cerebral cortex, cardiac muscle and skeletal muscle homogenates of 30-day-old Wistar rats. CK activity was measured also in the cytosolic (Cy-CK) and mitochondrial (Mi-CK) fractions from cerebellum. We verified that tCK activity was significantly inhibited by LGA in the cerebellum, but not in cerebral cortex, cardiac muscle and skeletal muscle. Furthermore, CK activity from the mitochondrial fraction was inhibited by LGA, whereas that from the cytosolic fraction of cerebellum was not affected by the acid. Kinetic studies revealed that the inhibitory effect of LGA on Mi-CK was non-competitive in relation to phosphocreatine. Finally, we verified that the inhibitory effect of LGA on tCK was fully prevented by pre-incubation of the homogenates with reduced glutathione (GSH), suggesting that this inhibition is possibly mediated by oxidation of essential thiol groups of the enzyme. Considering the importance of creatine kinase activity for energy homeostasis, our results suggest that the selective inhibition of this enzyme activity by increased levels of LGA could be possibly related to the cerebellar degeneration characteristically found in patients affected by L-2-hydroxyglutaric aciduria.     

Abrogation of IL-3 Requirements and Stimulation of Hematopoietic Cell Proliferationin Vitroandin Vivoby Carboxylic Acids

ABSTRACT: Short-chain fatty acids, such as butyrate and propionate, induce fetal globin gene expression and are under clinical investigation in the β-hemoglobinopathies. Limitations of the short-chain fatty acids as therapeutics include their rapid metabolism and a tendency to induce cell growth arrest if administered for prolonged periods. In studies described here, the cellular effects of other inducers of fetal globin, phenoxyacetic acid and derivatives of short-chain fatty acids and cinnamic acids, were investigated in the human erythroid cell line K562, the IL-3 dependent multi-lineage cell line (32D), and in mice and primates. Several test compounds supported 32D cell proliferation despite a 50-fold depletion of IL-3, which resulted in growth arrest and apoptotic death in control cells. The degree of proliferation induced by certain test compounds was similar to the degree of proliferation induced by Erythropoietin and G-CSF in the cells. Eight of ten compounds induced γ globin mRNA in K562 cells. A 2.5 to 6-fold increase in reticulocytosis was observedin vivoin mice treated with two prototype compounds. Pharmacokinetic studies of three prototype compounds demonstrated millimolar plasma concentrations after single oral doses for many hours in primates. These findings identify orally bioavailable compounds which induce γ globin gene expression and hematopoietic cell proliferation through an activity which partially abrogates requirements for IL-3. Such compounds provide potential for oral therapeutics which stimulate proliferation of hematopoietic cells of multiple lineages, as well as inducing fetal globin.     

Toxicity of prolonged exposure to ethanol and gasoline autoengine exhaust gases

A comparative chronic inhalation exposure study was performed to investigate the potential health effects of gasoline and ethanol engine exhaust fumes. Test atmospheres of gasoline and ethanol exhaust were given to Wistar rats and Balb C mice housed in inhalation chambers for a period of 5 weeks. Gas concentration and physical parameters were continually monitored during the exposure period. Several biological parameters were assessed after the exposure including pulmonary function, mutagenicity, and hematological, biochemical, and morphological examinations. The results demonstrated that the chronic toxicity of the gasoline-fueled engine is significantly higher than that of the ethanol engine.     

Tibial hemimelia: report on 37 new cases, clinical and genetic considerations

We report on 37 patients belonging to different families, who have the tibial hemimelia-split hand/foot syndrome. Genetic aspects and phenotypic manifestations are compared with previous reports of tibial hemimelia. An attempt to clinical and genetical approach is suggested.     

Effect of two different types of malnutrition on the rate of elimination of ethanol in rats

Rats were fed "3% casein" or a "calorie deficient" diet, in the form of commercial pellet diet (SDS) at 50% of the amount consumed by the control group, which was fed SDS pellets ad libitum. Both of the deficient groups showed failure of weight gain in comparison with the control group. Blood levels of ethanol were measured for 3 hr after intraperitoneal injection of 1 or 1.5 g/kg at 15, 29 and 36 days after commencement of the diet. In addition the calorie deficient group was studied immediately after feeding as well as in the fasting state. Blood levels of ethanol were measured and the apparent volume of distribution and rate of removal of ethanol from the blood were calculated. A rate of ethanol metabolism/g of liver was derived. The rate of removal of ethanol was markedly decreased in the 3% casein group to less than half of control values. Three hours after injection of ethanol circulating levels were less than 50 mg/100 ml in the control and calorie deficient groups but over 200 mg/100 ml in the group fed protein deficient diets. There were no major changes in volume of distribution and the only explanation for the finding is that there is a failure of ethanol metabolism in the rats fed the low protein diet. The implication is that protein deficient human populations who often consume considerable quantities of ethanol may have a high level of tissue exposure to ethanol though the rate of metabolite formation may be low.     

Years of potential life lost: application of an indicator for assessing premature mortality in Spain and Portugal

In this article, the authors present an analysis of causes of death in Spain and Portugal in 1984 based on a calculation of the "years of potential life lost" (YPLL) between the first and the 70th birthdays, the latter age corresponding approximately to the average life expectancy in both countries. This analysis of the YPLL led to a substantially different ranking of the main causes of death, based on what might be termed "premature mortality" compared with that obtained from more conventional mortality indices. According to this criterion, which is especially appropriate for the planning and evaluation of health interventions, the main causes of premature death (1-69 years) in the two countries of the Iberian peninsula are malignant tumours and, particularly in Portugal, violent deaths (especially motor-vehicle accidents, but also suicides). This is in contrast to the predominance of cardiovascular diseases indicated by other weightings of age-specific mortality rates. Portugal shows significantly worse YPLL rates than Spain not only for general mortality (45% higher than in Spain), but also for several major groups of causes. In Spain only malignant neoplasms, diabetes and chronic rheumatic heart diseases show higher specific mortality rates than in Portugal, based on traditional mortality indicators.(ABSTRACT TRUNCATED AT 250 WORDS)