Vertical transmission of human immunodeficiency virus (HIV) infection. Reactivity of maternal sera with glycoprotein 120 and 41 peptides from HIV type 1

The observation that approximately 70% of HIV-infected pregnant women do not transmit infection vertically suggests that antibody therapy may be effective in the prevention of transmission of HIV infection from mother to child. Currently, there is an incomplete understanding of the processes involved in vertical transmission of HIV infection. The elucidation of the serological basis of maternal immunity as it relates to protection from vertical transmission is the goal of this study. We have screened 20 maternal sera from HIV+ individuals of known vertical transmission status for reactivity with 31 peptides spanning the entire envelope glycoprotein of HIV-1. Of interest was reactivity to regions outside of the V3 loop of gp120. The findings have been examined in relationship to transmission status, as well as to in vitro anti-HIV-1 biological activity. Our results indicate that lack of vertical transmission is correlated with high viral neutralization activity, but not with antisyncytial activity nor with binding to the V3 peptides examined in this study. Also, the transmission group bound to fewer gp41 peptides when compared with the nontransmission group, suggesting that immune responses to gp41 may be important in preventing transmission. These findings may provide insights into the design of passive immunotherapies.

Internal radiation therapy for hepatocellular carcinoma. Results of a French multicenter phase II trial of transarterial injection of iodine 131-labeled Lipiodol

Preliminary Phase I trials have shown iodine 131 (131I)-Lipiodol (ethiodized oil; Laboratoires Guerbet, Aulnaysous-Bois, France) to be well tolerated and most likely effective in the treatment of hepatocellular carcinoma (HCC). In this multicenter Phase II trial, the authors tested the feasibility and reproducibility of this treatment in other medical institutions and evaluated its efficacy in 50 patients with unresectable Stage I or II HCC, by the classification of Okuda et al. The authors studied 47 men and 3 women (63.9 +/- 7.1 years old) with Stage I (n = 18) or II (n = 32) HCC, by the classification of Okuda et al., which was verified by histologic findings (n = 25), cytologic findings (n = 11), or association of a tumor with alpha-fetoprotein serum values greater than 500 micrograms/l (n = 14). This multicenter trial (1) confirmed that the 131I-Lipiodol treatment is well tolerated; (2) showed that there is a high reproducibility of results with respect to other institutions and an objective tumor response in 40% of the cases; and (3) indicated the necessity of performing a randomized controlled study.

Internal radiation therapy for hepatocellular carcinoma. Results of a French multicenter phase II trial of transarterial injection of iodine 131-labeled Lipiodol

Preliminary Phase I trials have shown iodine 131 (131I)-Lipiodol (ethiodized oil; Laboratoires Guerbet, Aulnaysous-Bois, France) to be well tolerated and most likely effective in the treatment of hepatocellular carcinoma (HCC). In this multicenter Phase II trial, the authors tested the feasibility and reproducibility of this treatment in other medical institutions and evaluated its efficacy in 50 patients with unresectable Stage I or II HCC, by the classification of Okuda et al. The authors studied 47 men and 3 women (63.9 +/- 7.1 years old) with Stage I (n = 18) or II (n = 32) HCC, by the classification of Okuda et al., which was verified by histologic findings (n = 25), cytologic findings (n = 11), or association of a tumor with alpha-fetoprotein serum values greater than 500 micrograms/l (n = 14). This multicenter trial (1) confirmed that the 131I-Lipiodol treatment is well tolerated; (2) showed that there is a high reproducibility of results with respect to other institutions and an objective tumor response in 40% of the cases; and (3) indicated the necessity of performing a randomized controlled study.

Immunological characteristics of the putative CD4-binding site of the HIV-1 envelope protein

As an extension of previous studies demonstrating the immunosuppressive properties of gp120, we have analyzed the immunological characteristics of gp120 peptides, derived principally from its putative CD4-binding site. Our studies indicate that peptides derived from this region do not stimulate proliferation of lymphocytes from HIV-seropositive donors with relatively normal numbers of CD4+ lymphocytes. No significant proliferation was observed in response to various concentrations of peptide, even in the presence of interleukin-2 (IL-2). Significant proliferation of these lymphocytes was observed in response to two recall antigens, cytomegalovirus (CMV) and tetanus toxoid (TT), and these responses were augmented by IL-2. Peripheral blood mononuclear cells from HIV-seronegative donors were cultured in the presence of TT and CMV and the peptides derived from gp120. Proliferation in the presence of these recall antigens was inhibited by these peptides in a dose-dependent manner. These studies demonstrate that at high concentrations, peptides from the putative CD4-binding site can inhibit proliferation of lymphocytes from normal donors in response to a recall antigen. The apparent immunosuppressive properties of this region highlight the pathogenic role played by HIV-1 envelope protein interactions with host cells.

Effects of ethanol on phospholipid acylation in rat erythrocytes: a model for a biochemical approach to membrane adaptation

Challenging intact erythrocytes from naive rats with ethanol resulted in dose-dependent decreases in rates of acylation of phosphatidylcholine and phosphatidylethanolamine. In erythrocytes from ethanol-treated animals, the responses were of lesser magnitude, indicating a lower sensitivity to ethanol. This relative resistance, typical of the state of tolerance, was not associated with increased baseline rates of acylation of PC and PE, nor with changes in fatty acid specificity of acylation reactions. Taken together, the data suggest that (1) intact rat erythrocytes represent a reliable and easily reproducible model for studying biochemical correlates of the adaptive response to ethanol; (2) phospholipid acylation reactions are implicated in the initial sensitivity and subsequent acquisition of tolerance to ethanol in membrane erythrocytes; (3) on the basis of the measured acylation reactions, rat erythrocytes appear to develop tolerance, but not dependence, to ethanol.

Estrogen modulates phospholipid acylation in red blood cells: relationship to cell aging

Ethinyl estradiol administered in vivo to female rats resulted in a mild anemia with a 120% increase in reticulocytosis. Consistent with a previous study, the red blood cell cholesterol-to-phospholipid molar ratio was decreased by 25%, whereas fatty acyl incorporation was significantly increased into phosphatidylethanolamine (PE) and not into phosphatidylcholine (PC), the major acyl acceptor in red blood cells. Analysis of this estrogen-dependent acylation increase as a function of cell age indicated that it was not expressed in reticulocytes but in erythrocytes and was associated with cell aging. Estrogen was further shown to increase the red blood cell susceptibility to peroxidation generated by incubation with H2O2. Altogether, the results suggest that estrogen indirectly increases phospholipid acylation in red blood cells by decreasing protection against oxidative damage, thereby favoring the action of endogenous phospholipases against oxidized substrates. This occurs predominantly in PE of oldest cells because 1) PE, being more unsaturated than PC, is more sensitive to oxidation, and 2) susceptibility to oxidation increases with cell age.

Changes in pattern of phospholipid acylation during in vivo aging of rat red blood cells

We have investigated the patterns of incorporation of stearic, oleic, and linoleic acids into phosphatidylcholine (PC) and phosphatidylethanolamine (PE) of intact red blood cells of differing age isolated by centrifugation on discontinuous density gradient. Acylation rates of PC and PE elicited marked declines from the reticulocyte to the young erythrocyte stage followed by minimal changes of acylating potency in older cells; this biphasic decay pattern was similar with the three fatty acids. Molar acylation rates were higher for PC than for PE in reticulocytes, whereas they were comparable in erythrocytes. PC served as preferred fatty acid acceptor in circulating red blood cells, a function which was largely accounted for by PC contained in the small percentage of circulating reticulocytes. On a per cell basis, this function of PC was due to the cumulative effects of higher molar acylation rates in reticulocytes and higher content in PC over PE in the red blood cell membrane. Acylation rates in PC and PE increased with the number of unsaturated bonds in the acylating fatty acid, regardless of cell age.

Effect of ethanol intake on lipoprotein lipase activity in rat heart

We examined the effects of the in vivo administration of ethanol on lipolytic activities assayed in rat post-heparin heart effluents, that hydrolyse tri-, di- and monoacylglycerol. Properties of triacylglycerol lipase (TAGL) are typical of lipoprotein lipase (LPL) whereas diacylglycerol (DAGL) and monoacylglycerol (MAGL) lipase activities hydrolyse sequentially the products of LPL action. After 15 days of ethanol intake, TAGL, DAGL and MAGL activities in post-heparin heart effluents were decreased respectively by 25, 38 and 22%; after 30 days, the decreases amounted to 81, 79 and 71%. After 30 days, but not after 15 days, ethanol increased the levels of triacylglycerol in plasma. Ethanol intake concomitantly decreased TAGL and DAGL activities in post-heparin effluents and in heart tissue extracts, whereas MAGL activity was decreased only in the latter extracts. We conclude that ethanol intake causes a marked impairment in heart LPL and in two closely-related heparin-releasable activities, seemingly by altering the production of a catalytically active enzyme. A distinct heparin-unreleasable MAGL appears to exist in heart, that could be ethanol-insensitive. Overall, the results suggest that a LPL-related alteration in fatty acid supply could contribute to the toxicity of ethanol in heart.

Prevention of recurrent variceal bleeding in alcoholic cirrhotic patients: prospective controlled trial of propranolol and sclerotherapy

We conducted a prospective randomized controlled study to evaluate the effectiveness of propranolol and sclerotherapy, compared to a control group, in the prevention of variceal rebleeding in alcoholic cirrhotic patients. Among the 79 patients included, the distribution of patients according to Child-Pugh classification was: A, 22%; B, 40%; and C, 38%. Propranolol was given twice daily with a mean final dose of 54 +/- 16 mg/day, this resulted in a mean reduction in resting heart rate of 26 +/- 7%. Sclerotherapy was performed weekly using 1% polidocanol. End points were rebleeding or death. During the mean follow up of 19 +/- 16 months, 43 patients bled and 22 patients died. The cumulative percentages of patients free of rebleeding at 1 year were: propranolol, 81% (95% confidence interval (CI): 63-92); sclerotherapy, 64% (95% CI: 45-82); control, 54% (95% CI: 36-71); these differences did not reach statistical significance. The cumulative percentages of patients alive at 1 year were: propranolol, 92% (95% CI: 76-98); sclerotherapy, 79% (95% CI: 58-91); control, 81% (95% CI: 60-93); these differences were not statistically significant. Alcohol withdrawal, which occurred in 66% of patients, was an independent predictive factor associated with a decreased risk of rebleeding or death. In conclusion, a life table analysis of patients free of rebleeding, as well as of patients surviving, revealed a tendency in favour of propranolol. The lack of a statistical support for these two favorable effects could be due to poor statistical power.(ABSTRACT TRUNCATED AT 250 WORDS)

Triacylglycerol in the human erythrocyte: quantification and fatty acyl turnover in normal subjects and chronic alcoholics

1. Triacylglycerol in erythrocytes from normal human subjects was estimated to average 2.7 +/- 0.7 nmol/10(10) cells, equivalent to 0.07% of total lipids or 0.3% of neutral lipids. 2. The specific activity of triacylglycerol labelling attained by incubating intact erythrocytes with [3H]oleic acid was 10 nmol/mumol, a value 20-fold higher than that of the highest labelled phospholipid, sphingomyelin; as isolated by ultracentrifugation over a density gradient, the youngest erythrocytes exhibited a labelling rate 10-fold higher than that of older cells. 3. The triacylglycerol content was not modified in erythrocytes from chronic alcoholics, whereas the mean rate of triacylglycerol labelling was 31% (P less than 0.05) higher than that of control subjects, and did not normalize 4 weeks after alcohol withdrawal. 4. These results indicate that triacylglycerol, although a quantitatively minor component, is one of the most active metabolites in the lipid matrix of the human erythrocyte membrane and appears to be implicated in the membrane response to antagonistic agents.

Pancreas divisum and pancreatitis: a coincidental association?

The aim of the present study is to assess the frequency of pancreas divisum and the features of patients with pancreas divisum in order to assess the role of this anomaly in the occurrence of pancreatitis. A total of 1049 endoscopic retrograde pancreatographies were studied between 1978 and 1988. Patients with pancreas divisum were studied in terms of their clinical findings and their disease (pancreatitis or not). Pancreas divisum was diagnosed in 62 patients (5.9%). No statistical differences with regard to age and sex were found between patients with and without pancreas divisum. The frequency of pancreas divisum was similar in the different groups of disease, especially chronic pancreatitis, acute pancreatitis, recurrent pancreatitis and idiopathic pancreatitis. The study of pancreatograms showed that dorsal ductal abnormalities alone were found as frequently as ventral alterations alone. Our results show that pancreas divisum cannot be directly implicated in the occurrence of pancreatitis, and should not prompt a systematic sphincterotomy of the accessory papilla. This treatment should only be considered in the rare cases of acute recurrent idiopathic pancreatitis with dorsal ductal dilatation and stenosis of the accessory papilla.

Severe hemorrhagic radiation proctitis advancing to gradual cessation with hyperbaric oxygen

We report a case of a male patient suffering from a severe hemorrhagic radiation proctitis which gradually ceased with hyperbaric oxygen. We discuss the mechanisms of chronic radiation injury and the effect of the hyperbaric oxygen. This therapy is proposed as an alternative to surgical intervention for this abnormality.

Cleavage of yeast and bacteriophage T7 genomes at a single site using the rare cutter endonuclease I-Sce I

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Acute ethanol treatment induces a bimodal response of phospholipid acylation rates in rat red blood cells

A single intraperitoneal injection of ethanol (4 g/kg) in rats elicited a bimodal response of acylation rates in phosphatidylcholine and phosphatidylethanolamine of intact red blood cells. Within an initial period, ethanol inhibited acylation rates. The inhibition then reversed, leading to increased values which persisted as long as ethanol was present in plasma. Acylation rates were not correlated to ethanol concentrations in plasma. We suggest that red cells first desensitize to, then overcompensate for the inhibitory effect of ethanol on acylation reactions. These adaptive changes may be one of the events mediating membrane tolerance to ethanol.

Pattern of the adaptive response of erythrocyte glycerolipid acylation processes during chronic alcoholism

Challenging intact erythrocytes from normal human subjects with ethanol resulted in dose-dependent decreases in rates of acylation of phosphatidylcholine (PC) and phosphatidylethanolamine (PE) while triacylglycerol (TAG) acylation was stimulated. In erythrocytes from alcoholic subjects, the responses were of lesser magnitude, indicating a lower sensitivity to ethanol. This in vitro resistance, typical of the state of tolerance, was associated in erythrocytes from alcoholic subjects with increased baseline rates of acylation of PC, PE and TAG, suggesting high levels of glycerolipid fatty acid turnover. These results suggest that (1) intact human erythrocytes are qualitatively and quantitatively valid for studying the adaptive response to ethanol; and (2) chronic alcoholism is associated with increases in turnover rates of the acyl moieties of lipid membrane components regardless of the pattern of initial sensitivity to ethanol. Increased acylation rates during chronic alcoholism might modify the remodeling of the lipid matrix and thereby the membrane function.