Lipoprotein metabolism in nonresponders to increased dietary cholesterol

We have studied the effect of increased dietary cholesterol on production and degradation of plasma very low density lipoproteins and low density lipoproteins. We studied five unselected normal volunteers who were on weight-maintaining diets consisting of 45% carbohydrate, 40% fat, and 15% protein with a ratio of polyunsaturated to saturated fat of 0.4. Cholesterol content was 150 mg/1000 kcal in Period A and 500 mg/1000 kcal in Period B. Subjects were fed each diet for 4 to 5 weeks. The turnover of apoproteins B in very low density and low density lipoproteins and of triglyceride in very low density lipoproteins were measured during the last 2 weeks of each study period using 131I-labeled very low density lipoproteins and 125I-labeled low density lipoproteins and 2-3H-glycerol, respectively. There was no significant change in plasma total cholesterol or triglycerides or in low density lipoprotein cholesterol levels during the high cholesterol versus the low cholesterol diet. Similarly, high cholesterol intake had no effect on the rate of production or clearance of apo B in very low density and low density lipoproteins or of triglyceride in very low density lipoproteins. These data indicate that the flux of very low density lipoproteins does not change in nonresponders to high cholesterol diets.

Generalized van der Waals theory. VII. Interface profiles and surface tension

An equilibrium theory of fluids based on a simple free-energy density functional developed and tested in several preceding articles is here applied to estimate the shape and surface tension of a gas/liquid interface in a simple LJ(12-6) fluid. The calculation is carried out at several different levels of approximation. In the simplest case when a step function profile is assumed the surface tension is obtained analytically. It is too high by about 50%. By using a moment expansion of the nonlocal free energy functional, the surface tension can be reduced to a simple one-dimensional integral. The result is now only slightly high. Finally, a variational calculation assuming a tanh form for the profile has been carried out. The effect of nonlocal entropy is examined and found to cause a drop in the surface tension by 5-10%. The results for the surface tension and width of the profile are in good agreement with experiment and simulation (deviation c. 0%) when plotted against T/Tc.

1,2-Dichloropropane: metabolism and fate in the rat

1. The metabolism of 1,2-dichloropropane in the rat has been investigated. The major urinary metabolite has been isolated and identified as N-acetyl-S-(2-hydroxypropyl)cysteine. Two minor metabolites of 1,2-dichloropropane have been identified as beta-chlorolactate and N-acetyl-S-(2,3-dihydroxypropyl)cysteine. 2. The fate of 1-chloro-2-hydroxypropane, a proposed intermediate metabolite of 1,2-dichloropropane, has been investigated. Apart from its known urinary metabolite, N-acetyl-S-(2-hydroxypropyl)cysteine, two oxidative metabolites were detected. These were identified as beta-chlorolactaldehyde and beta-chlorolactate. 3. A pathway is proposed for the metabolism and fate of 1,2-dichloropropane in the rat. This accounts for previous observations made for the fate of radioactivity from administration of 1,2-dichloro[1-14C]propane. 4. The microbial and mammalian metabolism of several halogen-containing foreign compounds is discussed.

Appropriateness review: a planning function or a regulatory tool?

The appropriateness review process can be used as a planning function by hospitals; however, hospitals and their medical staffs should become involved in the process to ensure that it does not become a regulatory tool.

Enzyme-linked immunosorbent assay (ELISA): a study of antibodies to Mycobacterium tuberculosis in the IgG, IgA and IgM classes in tuberculosis, sarcoidosis and Crohn's disease

Enzyme-linked immunosorbent assay (ELISA) has been used to study the levels of antibody binding to the soluble antigens of Mycobacterium tuberculosis (BCG) in the IgG, IgM and IgA classes in sera from patients with tuberculosis, sarcoidosis and Crohn's disease. Of the patients with tuberculosis, 75% had significantly elevated levels of anti-M. tuberculosis antibodies in the IgG class. The levels of antibodies in the IgM and IgA classes were much less discriminative. Many of the patients with sarcoidosis and Crohn's disease had significantly elevated levels of antimycobacterial antibodies, principally in the IgM and IgA classes. These elevated levels of antibody were not related to the total levels of the immunoglobulin classes. For the purpose of serodiagnosis, an estimation of the antimycobacterial antibodies in the IgG class gives the most discriminative results.

The specificity of the humoral immune response to soluble mycobacterial antigens in tuberculosis

A high proportion of patient with tuberculosis have been shown to produce significant levels of antibodies to antigens unique to Mycobacterium tuberculosis, antigens restricted to the slowly growing mycobacteria and antigens common to all species in the genus. About 20% of patients with this disease do not have significantly elevated levels of antibodies to any of these groups of antigens. Consequently, the availability of highly purified soluble antigens specific for M. tuberculosis would not permit more cases of tuberculosis to be diagnosed serologically.

Pituitary and testicular fibrosis in association with retroperitoneal fibrosis

A patient is discussed who originally presented with retroperitoneal fibrosis, and subsequently developed both pituitary fibrosis and testicular fibrosis. Replacement of testicular tissue by fibrosis has not previously been described in this condition, while we have only been able to find a single previous report of pituitary fibrosis. Fibrous replacement of testis and pituitary should be considered as a further manifestation of the midline fibrosing syndrome.

Do genealogical patterns in purple photosynthetic bacteria reflect interspecific gene transfer?

It is generally thought that interspecific (lateral) transfer of genes is so extensive among bacteria that it is difficult, and perhaps impossible, to determine their phylogenetic relationships. Ambler and coworkers reflect this in their suggestion that the relationships seen among cytochrome c sequences of the Rhodospirillaceae are merely the result of a haphazard lateral transfer of the particular gene, and give no indication of the true bacterial phylogenies. However, if comparative analysis of several unrelated macromolecules yields essentially the same phylogenetic tree, then that pattern is extremely unlikely to reflect the lateral transfer of genes. We have also determined 16S ribosomal RNA catalogues for many of the Rhodospirillaceae in investigated by Ambler et al. and here we use these two sets of data to compare molecular phylogenies for these bacteria.

Regulation of phosphate accumulation in the unicellular cyanobacterium Synechococcus

The phosphorus contents of acid-soluble pools, lipid, ribonucleic acid, and acid-insoluble polyphosphate were lowered in Synechococcus in proportion to the reduction in growth rate in phosphate-limited but not in nitrate-limited continuous culture. Phosphorus in these cell fractions was lost proportionately during progressive phosphate starvation of batch cultures. Acid-insoluble polyphosphate was always present in all cultural conditions to about 10% of total cell phosphorus and did not turn over during balanced exponential growth. Extensive polyphosphate formation occurred transiently when phosphate was given to cells which had been phosphate limited. This material was broken down after 8 h even in the presence of excess external orthophosphate, and its phosphorus was transferred into other cell fractions, notably ribonucleic acid. Phosphate uptake kinetics indicated an invariant apparent K(m) of about 0.5 muM, but V(max) was 40 to 50 times greater in cells from phosphate-limited cultures than in cells from nitrate-limited or balanced batch cultures. Over 90% of the phosphate taken up within the first 30 s at 15 degrees C was recovered as orthophosphate. The uptake process is highly specific, since neither phosphate entry nor growth was affected by a 100-fold excess of arsenate. The activity of polyphosphate synthetase in cell extracts increased at least 20-fold during phosphate starvation or in phosphate-restricted growth, but polyphosphatase activity was little changed by different growth conditions. The findings suggest that derepression of the phosphate transport and polyphosphate-synthesizing systems as well as alkaline phosphatase occurs in phosphate shortage, but that the breakdown of polyphosphate in this organism is regulated by modulation of existing enzyme activity.

The existence of inflammatory bowel lesions in gluten-sensitive enteropathy

Three patients with coincident coeliac disease and inflammatory bowel disease are described. In 2 patients with known coeliac disease the recurrence of diarrhoea was not due to dietary deviation but to an additional large bowel pathology.

Lung function in an Australian population: 2. Spirometric performance and cigarette-smoking habits

The FEV1, FVC and FEV1/FVC% in 12016 females and 18 359 males were related to cigarette-smoking habits. Over all, non-smokers had significantly better lung function than cigarette smokers. Ex-smokers of either sex had significantly higher FEV1 and FEV1/FVC% than cigarette smokers, but the FVC values were higher only in females. With consumption in excess of 10 cigarettes per day, deterioration in lung function was manifest in both sexes, but was greater in males than females. The mean chronological age of males who smoked from 30 to 50 cigarettes per day was 12.9 years and 9.6 years less than would have been predicted on the basis of their FEV1 and FVC values respectively. The corresponding values in women were 9.3 years and 7.9 years respectively. Additionally, the deterioration in lung function with increasing age was greater in cigarette smokers than in non-smokers.

Lung function in an Australian population: 1. Spirometric standards for non-smoking adults

Relationships between age, height, weight and spirometry with FEV0.5, FEV1, FVC and FEV1/FVC are described for a sample of 6275 female and 6511 male non-smoking adults living in New South Wales. Prediction equations for ventilatory function tests are derived from non-smokers and compared with other standards that are available in a population sample of 31172 subjects. It is concluded that the standards described in this paper are more appropriate for use in Australian populations. Nomograms for predicting FEV1 and FVC in females and males are provided.

Variation in amount of enzyme protein in natural populations

Among strains of Drosophila melanogaster each derived from a single fertilized female taken from natural populations, there is variation in both alcohol dehydrogenase (ADH) activity and the amount of ADH protein. The correlation between ADH activity and number of molecules over all strains examined is 0.87 or 0.96 in late third instar larvae depending on whether the substrate is 2-propanol or ethanol. With respect to the two common electrophoretic allozymic forms, F and S, segregating in these populations, the FF strains on the whole have higher ADH activities and numbers of ADH molecules than the SS strains. Over all strains examined, enzyme extracts from FF strains have a mean catalytic efficiency per enzyme molecule higher than that of enzyme extracts from SS strains when ethanol is the substrate, and much higher when 2-propanol is the substrate. One FF strain had an ADH activity/ADH protein ratio characteristic of SS strains.

Aggregation of antidepressant drugs in aqueous solution

Light scattering, conductivity and pH methods have been used to examine the aggregation in aqueous solution of a series of antidepressant drugs. The drugs investigated included the hydrochlorides of amitriptyline, butriptyline, protriptyline, nortriptyline, imipramine, desipramine, clomipramine, dothiepin, dibenzepin, opipramol, iprindole, doxepin, mianserin and maprotiline. No significant association of dibenzepin, mianserin or maprotiline hydrochlorides could be detected up to their respective solubility limits. A micellar pattern of association was established for all other compounds. Critical micelle concentrations and micellar properties are reported.

Drinking, smoking and drug-taking patterns in a predominantly lower socioeconomic status sample: comparison with Medicheck sample

The drinking, smoking, and drug-taking patterns of 9829 adult members of the Australian Workers Union in Sydney are compared with data collected through the Medicheck Referral Centre. Overall, the two sets of data are very similar, but the results of this survey point to the high prevalence of heavy alcohol consumption, and of regular drug-taking in young people.

Comparison of enteric identification systems

An evaluation of methods for identification of Enterobacteriaceae was made employing the new commercial Micro-Media Enteric System (MMES) with that of the Analytab Products Incorporated (API) and the Conventional tube media schema as suggested by the Center for Disease Control (CDS). The MMES system employed 20 biochemical tests, the API 21, and the CDC procedure 25. Sixteen of these were identical biochemical tests. Two hundred clinical isolates of Enterobacteriaceae were tested employing procedures recommended by the manufacturers of MMES and API, and methods suggested by CDC. Among the sixteen identical biochemical tests the agreement was 98.0% (Conventional), 98.2% (API), and 97.98% (MMES). Bacteria misidentified by the API system totaled 5 (2.5%), 12 (6%) for the Conventional, and 13 (6.5%) for the MMES. Five of the bacteria misidentified with the MMES procedure were due to false positive citrate tests. This problem was subsequently eliminated. The results of this study indicated that the new MMES method for identification of Enterobacteriaceae compared favorably with both the API and Conventional procedures. However, significant advantages of the MMES method were evident in initial purchase price, utilization of technology time, and less tedium performing the test.

Evaluation of antigen-induced buffy coat leucocyte aggregation as a simple test of allergic reactivity

The phenomenon of antigen-induced aggregation of human buffy coat leucocytes correlates well with skin testing using purified protein derivative of tuberculin as the antigen and in this system appears to be a simple, sensitive test of cell-mediated immunity. The same phenomenon may, however, be used as an indicator of humoral immunity. In addition antigen-induced buffy coat leucocyte aggregation is suppressed by serum from patients with Hodgkin's disease and sarcoidosis. The possible uses and also the limitations of this test are discussed.

Raised alpha-fetoprotein levels associated with minor congenital defect

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Uptake of C4 dicarboxylates and pyruvate by Rhodopseudomonas spheroides

The uptake of C4 dicarboxylates by cells from exponential cultures of Rhodopseudomonas spheroides followed saturation kinetics at concentrations below 100 muM with Km values for succinate, malate, and fumarate of 2.7, 2.3, and 0.8, respectively. Corresponding Vmax values of 50, 52, and 67.5 nmol/min per mg of protein at 20 C were obtained. Each of these compounds interfered competitively with uptake of the others, and a common transport system appears to be involved. Fructose-grown cells took up C4 dicarboxylates only at very low rates, and pyruvate-grown cells took up C4 dicarboxylates at one-third the rates found with succinate-grown cultures. Malonate and maleate inhibited uptake less severely, and aspartate and alpha-ketoglutarate had no effect at 100-fold excess. Divalent metals stimulated uptake. Light or respiration was required for uptake, and entered materials were rapidly converted to other metabolities, notably amino acids. Pyruvate entry appeared to be mediated by several systems, of which only one could be resolved kinetically. This system had a Km of 13 muM and Vmax of 5.6 nmol/min per mg of protein at 20 C. A number of related mono- and dicarboxylates interfered with pyruvate uptake. The pyruvate uptake system was distinguishable from the C4 dicarboxylate system by the absence of divalent cation stimulation and by substrate and inhibitor specificity.

CO2 fixation and its regulation in Anacystis nidulans (Synechococcus)

Anacystis nidulans (Synechococcus) had a minimal doubling time of 5 hrs at 30 degrees C at saturating light intensity and carbon dioxide concentration. Half maximal growth rates in saturating CO2 occured at a light intensity of 0.54 mW per cm2, and there was an apparent threshold intensity of 0.13 mW per cm2 below which no growth occurred. Growth rate in saturating light was dependent on the concentration of CO2+H2CO3 in the medium, rather than on total dissolved CO2; half maximal rates were estimated at 0.1 mM CO2+H2CO3. Under saturating conditions of light and CO2, 14CO2 was fixed primarily into 3-PGA, and subsequently moved into sugar phosphates and amino acids. Incorporation into aspartate was relatively slow. CO2 fixation was strictly light-dependent. The changes in adenylate and pyridine nucleotide pools were followed in light/dark and dark/light transitions. Whereas adenylates relaxed slowly over 15-20 min to the concentrations characteristic of illuminated cells following the abrupt changes induced by darkening, the sharp drop in intracellular NADPH showed little dark recovery although rapid restoration occurred on reillumination. Other pyridine nucleotides showed no changes during these transitions. The nucleotide specificity and Km of partially purfied GAP dehydrogenase suggest a role for this enzyme in the regulation of CO2 fixation.

Phosphate utilization and alkaline phosphatase activity in Anacystis nidulans (Synechococcus)

Anacystis nidulans (Synechococcus) was maintained in a medium of low phosphate concentration (0.1 mM) and grew with a normal doubling time of 5 hrs at 30 degrees C. Such cultures had a normal pigment composition and alkaline phosphatase was detectable at low specific activities only. The onset of phosphate-limited growth occurred when the phosphate concentration in the medium fell to a value below 4 muM (the limit of accurate determination by the assay method used ) and resulted in increases in alkaline phosphatase activity, reaching a final 10 to 15 fold increase in specific activity after a period of several hours. Marked changes in the overall pigment composition occurred in this period of growth restriction. The addition of phosphate to such cultures resulted in a halt in synthesis of the enzyme and the restoration of normal pigmentation before growth resumed at the normal rate. Several oraganic phosphate esters could replace inorganic phosphate for growth and were also hydrolyzed by the partially purified enzyme, but growth rates were characteristically lower and the specific activity only 3 to 4 fold higher than in cultures grown in phosphate excess. Studies with the partially purified enzyme suggested that it differed in some of its properties from other alkaline phosphatases described in the literature.

Nucleotide pools and adenylate energy charge in balanced and unbalanced growth of Chromatium

Adenine nucleotide pools and their energy charge were measured during balanced and unbalanced growth of photoheterotrophic Chromatium cultures. The methods used involved rapid sampling, accurate to within 1 s, from isotopically labeled cultures followed by chromatographic separation of individual nucleotides. During balanced growth, both energy charge and adenosine triphosphate (ATP) concentrations, whether expressed as a function of cell protein or intracellular water, were slightly higher in limiting light intensities than in cultures growing at their maximal rate in bright light. The ATP found corresponded to 4.67 +/- 0.08 nmol/mg of protein or 1.34 +/- 0.57 mM for low-light cells and to 4.41 +/- 0.58 mmol/mg of protein or 0.85 +/- 0.12 mM for high-light cells. Corresponding energy charges were 0.85 +/- 0.02 and 0.81 +/- 0.02. Illumination shifts caused differential synthesis of photosynthetic pigments lasting 2 to 3 h without corresponding perturbation of adenine nucleotide levels. Cultures in intermittent illumination were severely affected by some cycle durations; they had abnormal morphology and very high bacteriochlorophyll-to-protein ratios. In such cultures, energy charge and nucleotide concentrations were within normal limits and relaxed to the dark steady state during the dark periods. Arsenate at AsO(4) (3-) to PO(4) (3-) ratios of 10:1 in the medium retarded growth, but no abnormality of charge or quantity of phosphate-containing nucleotides was found. These experiments therefore suggest that, within experimental error, neither the size nor the charge of the adenylate pools governs growth rate in Chromatium. Moreover, these parameters do not appear to be concerned in regulating the synthesis of photosynthetic apparatus in this organism.

Nucleotide pools in growing Chromatium strain D

The growth rate of Chromatium at limiting light intensities is not regulated by either the ratio or the concentration of nucleoside phosphates, although transient changes in these parameters may affect the activities of biosynthetic enzymes.