Inhibition of pro-oxidant-induced mitochondrial pyridine nucleotide hydrolysis and calcium release by 4-hydroxynonenal

Intra- and extra-mitochondrial Ca2+ participates in vital cellular processes. This work investigates the influence of 4-hydroxynonenal (HNE) on pro-oxidant-induced Ca2+ release from rat liver mitochondria. Ca2+ movements across the mitochondrial inner membrane, the pyridine nucleotide redox state and pyridine (nicotinamide) nucleotide hydrolysis were analysed. HNE did not influence Ca2+ uptake by mitochondria, but inhibited in a concentration-dependent manner Ca2+ release induced by t-butylhydroperoxide (tbh). Total inhibition was achieved with about 50 microM-HNE. Ca2+ release induced by the pro-oxidant alloxan was also inhibited by HNE. Oxidation of pyridine nucleotides, induced by tbh through the concerted action of glutathione peroxidase, glutathione reductase and the energy-linked transhydrogenase, was not affected by up to 50 microM-HNE. In contrast, HNE inhibited pyridine nucleotide hydrolysis in a concentration-dependent manner. The data suggest that HNE toxicity may be in part attributed to an impaired intramitochondrial Ca2+ homeostasis.

[Bulk-forming agents as laxatives in geriatric patients]

Constipation in elderly long-care patients is an important problem. We compared the daily administration of three bulk-forming agents, semen psyllii (Effersyllium), wheat bran with karaya gum (Crusca di Fior) and bruised linseed, with the routine laxative therapy in our clinic based on lactulose (Duphalac) and a combination of paraffin oil and phenolphthalein (Agarol). To evaluate these two laxative regimens the following parameters were monitored: quantity and quality of the feces and of additional laxatives used for regular defecation; acceptance by the patient; costs per patient and day. The results of this study show that daily administration of a laxative is significantly more efficient than periodic administration, and that daily administration of a bulk-forming agent is, at the same level of effectiveness, less expensive (-35%) than therapy with lactulose alone.

[Chronic hepatitis B: diagnostic value of hepatitis-B-virus DNA analysis in serum and liver tissue]

The diagnostic value of hybridization analyses for the detection of hepatitis B virus (HBV) DNA in serum and liver tissue was investigated in 79 patients with chronic liver disease. Active viral replication was demonstrated by the detection of HBeAg or HBV-DNA in serum or liver tissue. However, HBV-DNA was also detected in the absence of HBeAg in serum. No correlation was found between the presence of HBV-DNA in serum or liver tissue and clinico-chemical or histological disease. In HBsAg-negative patients no HBV-DNA was detected in serum or liver tissue. These data indicate that serological markers are sufficient for the diagnosis of HBV infection. However, detection of HBV-DNA in serum or active viral replication in liver tissue is important in selecting patients for antiviral therapy (e.g. interferon) and monitoring its efficacy.

[Acute hepatitis following administration of fansidar]

Since 1971 pyrimethamine-sulfadoxine (Fansidar, Roche) has been used worldwide for prophylaxis and therapy of chloroquine resistant Plasmodium falciparum malaria. The drug monitoring team of the producing firm has received reports of a number of cutaneous adverse reactions, some severe, and a few even with fatal outcome. Liver reactions were also encountered, with severe cases only in the recent literature. We report on two patients with hepatitis in temporal relationship to pyrimethamine-sulfadoxine, the first with a second event after later exposure to the same drug. After discontinuing the medication the liver function abnormalities returned to normal limits within a few weeks. Liver biopsy and a positive lymphocyte transformation test against sulfadoxine, a component of Fansidar, strongly suggest that Fansidar was the cause of hepatic injury.

Polio trial: an early efficient clinical trial

The Salk Vaccine Field Trial was a randomized, placebo-controlled trial designed to test the efficacy of the Salk killed virus vaccine. Although the trial was not without some problems, both in design and analysis, none was important enough to raise serious questions about the results. Thus, the design of the Field Trial was well adapted to the demanding requirements. The trial owes its success in a large part to substantial public involvement. In designing future, large-scale, simple trials, we may still be able to benefit from the lessons of the Polio Vaccine Trial.

Choosing covariates in the analysis of clinical trials

Much of the literature on clinical trials emphasizes the importance of adjusting the results for any covariates (baseline variables) for which randomization fails to produce nearly exact balance, but the literature is very nearly devoid of recipes for assessing the consequences of such adjustments. Several years ago, Paul Canner presented an approximate expression for the effect of a covariate adjustment, and he considered its use in the selection of covariates. With the aid of Canner's equation, using both formal analysis and simulation, the impact of covariate adjustment is further explored. Unless tight control over the analysis plans is established in advance, covariate adjustment can lead to seriously misleading inferences. Illustrations from the clinical trials literature are provided.

[Giant adenoma of Brunner's glands]

Bleeding, obstruction and invagination are the common symptoms of large polyps in the duodenal bulb. We present 2 patients with a large ulcerated Brunner's gland adenoma. The clinical findings were acute bleeding and nonspecific upper gastrointestinal symptoms. The treatment was surgical due to a suspect histological finding in one case, a thick stalk in the other, and the fact that endoscopic polypectomy is a much higher risk procedure in the duodenum than in the colon.

The provisional normal MSAFP screen

Patients with a provisional normal MSAFP screen appear to be at significant risk of giving birth to a child with a chromosomal abnormality. Failure to recognize this risk or act upon it may deprive patients of all of their reproductive options. Based upon our experience over an 18 month period, a protocol to evaluate the provisional normal MSAFP is reported.

Constructive thinking: a broad coping variable with specific components

The structure of constructive thinking and the development of an instrument for measuring it, the Constructive Thinking Inventory (CTI), were discussed. Scales were derived from a factor analysis of an item domain of people's everyday automatic thinking. When the CTI and other tests were factor analyzed, separate intellective and nonintellective factors were found, with the CTI loading more strongly on the nonintellective factor than any other test. Only measures of IQ loaded on the intellective factor. The global constructive thinking scale correlated significantly with success in work, love, social relationships, and in maintaining emotional and physical well-being, but not with academic achievement, the only criterion with which the measures of IQ correlated strongly. The patterns of correlations between the CTI scales and the various criteria as well as the factor analysis demonstrated that the construct of constructive thinking is differentiated as well as integrated.

[A drowning accident of long duration with deep hypothermia and rewarming with extracorporeal circulation. A report of 2 patients]

Two nearly drowned, 2 9/12 and 3 6/12 years old boys with profound hypothermia were admitted to our pediatric intensive care unit with all signs of clinical death. Both patients could be rewarmed and oxygenated by extracorporeal circulation. One of them died 36 hours after the accident with severe brain edema. The second one survived without any defect. Rewarming of cold-water nearly-drowned patients by extra-corporeal circulation seems to be a very effective way of treatment.

Rating intervals: an experiment in peer review

The National Institute of Health (NIH) peer review process for research grant applications is one of the largest and most respected systems of its kind in the world. Recently, however, the distribution of raw priority scores voted by NIH study sections has been skewed, and the rating behavior of individual review groups has been quite variable. These phenomena have made funding decisions more difficult. To achieve greater uniformity of rating behavior and a broader description of scores, an experiment was conducted involving 24 study sections. Standard adjectival descriptors and standard rating scales were used. On a random basis, half of the study sections were instructed to vote in units of 0.1 while the other half used an interval of 0.5. The results of this study have now been translated into standard practice at NIH.

[Accidental drowning with extreme hypothermia--rewarming with extracorporeal circulation]

A 3 1/2 year old boy had fallen into a fishpond. After about one hour the boy was brought to our hospital. He was cyanotic and bloated, the rectal temperature was 18.4 degrees C. There was no heart beat, the pupils were wide without reaction to light. Via a sternotomy the heart lung machine was connected and core rewarming was achieved. After 7 days of artificial respiration the boy could be extubated, after 16 days the boy left our hospital without neurological consequences.

Chain configuration and flexibility gradient in phospholipid membranes. Comparison between spin-label electron spin resonance and deuteron nuclear magnetic resonance, and identification of new conformations

The electron spin resonance spectra of 1-myristoyl-2-[n-(4,4-dimethyloxazolidine-N-oxyl)myristoyl]-sn- glycero-3-phosphocholine spin-label positional isomers (n = 6, 10, and 13) have been studied in oriented, fully hydrated bilayers of dimyristoylphosphatidylcholine, as a function of temperature and magnetic field orientation. The spectra have been simulated using a line-shape model which incorporates chain rotational isomerism, as well as restricted anisotropic motion of the lipid molecules as a whole, and which is valid in all motional regimes of conventional spin-label electron spin resonance (ESR) spectroscopy. At least one component of the lipid motion is found to lie in the slow-motion regime for all label positions, even in the fluid liquid crystalline phase, well above the phase transition. In the gel phase, the chain isomerism lies in the slow-motional regime, and the overall motions are at the rigid-limit. In the fluid phase, the chain isomerism is in the fast-motional regime, and the chain axis motions are in the slow regime. This indicates that the commonly used motional-narrowing theory is not appropriate for the interpretation of spin-label spectra in biological membranes. The simulation parameters yield a consistent description for the chain order and dynamics for all label positions. The correlation times and order parameters for the overall motion are the same at all positions down the chain, whereas the chain conformation and trans-gauche isomerism rate display a characteristic flexibility gradient, with increasing motion towards the terminal methyl end of the chain. Significantly, it is found that all six distinct tetrahedral orientations of the hyperfine tensor at the labeled segment are required for a consistent description of the chain isomerism. For the C-6 segment only the 0 degree (trans) and two 60 degrees (gauche) orientations are significantly populated, for the C-10 position two further 60 degrees orientations are populated, and for the C-13 position all orientations have non-vanishing populations. Detailed comparisons have been made with the results of 2H nuclear magnetic resonance (NMR) measurements on dimyristoylphosphatidylcholine labeled at the same position in the sn-2 chain, and using an identical motional model. The parameters of overall reorientation, both order parameter and correlation times, have very similar values as determined by ESR and NMR. The major difference between the results from the two methods lies in the conformational populations at the labeled chain segment and the trans-gauche isomerization rate in the gel phase. The conformational order is much lower for the spin-labeled chain segments than for the corresponding deuterium-labeled segments, and the isomer interconversion rates in the gel phase(although displaying a mobility gradient in both cases) are found to be much slower in the former case. In addition the spin-label measurements provide information on the macro order (chain tilt), which is only available from oriented samples. These results are consistent between the different spin label positions and are in agreement with the findings from x-ray diffraction.

A controlled trial of extended radical versus radical mastectomy. Ten-year results

In view of increasing debate over possible benefit of more complete surgery compared to conservative procedures, a randomized controlled trial contrasting the then standard Halsted radical (RDL) operation with the more complete extended radical (EXT) mastectomy was initiated in 1973. Between November 1973 and July 1982, 123 women younger than 70 years of age and at clinical Stages I and II were enrolled. Of the total series, 112 were treated by the same surgeon and confirmed pathologically as having invasive mammary carcinoma. In this more homogeneous subgroup, the 10-year survival rates (and standard errors) were for RDL, 60% (+/- 7%) and for EXT, 74% (+/- 6%) (P value for comparison of survival curves = 0.13). In patients from this subgroup with central-medial tumors, comprising 62% of the total, survival after RDL at 10 years was 60% (+/- 8%), and after EXT 86% (+/- 6%) (P = 0.025). In the remaining patients with lateral tumors, survival rates were unaffected by treatment: 58% (+/- 13%) and 56% (+/- 11%), respectively (P = 0.62). Comparison of a nonrandomized series of 266 RDL and 124 EXT patients treated between 1960 and 1978 found differences consistent with those of the randomized study, although not statistically significant.

Constructive thinking: A broad coping variable with specific components

The structure of constructive thinking and the development of an instrument for measuring it, the Constructive Thinking Inventory (CTI), were discussed. Scales were derived from a factor analysis of an item domain of people's everyday automatic thinking. When the CTI and other tests were factor analyzed, separate intellective and nonintellective factors were found, with the CTI loading more strongly on the nonintellective factor than any other test. Only measures of IQ loaded on the intellective factor. The global constructive thinking scale correlated significantly with success in work, love, social relationships, and in maintaining emotional and physical well-being, but not with academic achievement, the only criterion with which the measures of IQ correlated strongly. The patterns of correlations between the CTI scales and the various criteria as well as the factor analysis demonstrated that the construct of constructive thinking is differentiated as well as integrated.

[Surgical treatment of the unstable thorax in respiratory insufficiency]

Sixteen patients with traumatic flail chest underwent surgical stabilization using procedures introduced by Rehbein, Judet and Vecsei. Compared with sixteen patients treated by internal stabilization with intermittent positive pressure respiration, there are some advantages: time of artificial respiration is shortened, early mobilization is possible, nursing is easier, the costs are lower. The procedure is indicated in those patients, in whom long-term artificial respiration is not necessary for other reasons.

Hepatocellular carcinoma in alcoholic liver disease: no evidence for a pathogenetic role of hepatitis B virus infection

Hepatocellular carcinoma tissues from HBsAg-negative patients with chronic alcoholic liver disease were investigated for the presence of hepatitis B virus DNA. Southern blot analyses of DNA extracted from the hepatocellular carcinomas were negative for hepatitis B virus DNA in all 17 patients examined, at a level of sensitivity of less than 0.01 genome equivalent per cell. Similarly, in liver tissues from another 30 patients with alcoholic cirrhosis without hepatocellular carcinoma, no hepatitis B virus DNA was detectable. We conclude that in our patients there is no molecular evidence for a contribution of hepatitis B virus infection to the development of hepatocellular carcinoma in alcoholic liver disease.

Low O6-alkylguanine DNA alkyltransferase activity in the peripheral blood lymphocytes of patients with therapy-related acute nonlymphocytic leukemia

Chemotherapeutic agents such as procarbazine, which produce methylated bases in DNA, are used to treat many Hodgkin's disease (HD) and non-Hodgkin's lymphoma (NHL) patients. A small proportion of such patients develop secondary malignancy. We examined the possibility that those patients who develop secondary malignancy have low endogenous levels of O6-alkylguanine DNA alkyltransferase (AGT) activity and are therefore more sensitive to the mutagenic and carcinogenic effects of their treatment. We assayed AGT activity in peripheral blood lymphocytes from patients with HD, NHL, acute nonlymphocytic leukemia (ANLL) de novo, and therapy-related ANLL, as well as a group of normal control subjects. Studies in normal controls showed that at least over a short term of 1 week, individuals have characteristic AGT levels, although some individuals sampled repeatedly over several months showed high variation. Mean AGT activities +/- SE for the various groups studied were (fmol/micrograms of DNA): normal control group, 7.05 +/- 0.36; HD and NHL patients (prior to treatment), 4.97 +/- 0.42; HD-NHL patients receiving procarbazine, 3.88 +/- 0.44; ANLL de novo, 7.78 +/- 1.72; and therapy-related ANLL, 4.30 +/- 0.58. AGT activity decreased in the peripheral blood lymphocytes of some individuals taking procarbazine. The mean AGT activity in the procarbazine-treated patients was low, as was the activity for the therapy-related ANLL patients.

ATP-dependent Ca2+ uptake and Ca2+-dependent protein phosphorylation in basolateral liver plasma membranes

ATP-dependent Ca2+ uptake was measured in vesicles of rat liver cell basolateral plasma membranes. Nucleotide-dependent uptake was specific for ATP and observed at pH 7.0 and 7.4/7.5 but not at pH 8.0. ATP-dependent Ca2+ transport was only observed in the presence of Mg2+. Kinetic analysis of ATP-dependent transport revealed an apparent Km in the submicromolar region. Addition of calmodulin and trifluoperazine had no effect on ATP-dependent uptake. A Ca2+-dependent, phosphorylated intermediate with the apparent molecular weight of 135,000 could be demonstrated in the basolateral plasma membranes. Phosphorylated intermediates with apparent molecular weights of 200,000 and 110,000 were demonstrated in microsomes and appeared to contaminate 'basolateral' membrane protein phosphorylation. The results suggest that a 135,000 molecular weight protein is a Ca2+-ATPase and the enzymatic expression of the liver cell basolateral membrane Ca2+ pump.