Beta-oxidation of medium chain (C8-C14) fatty acids studied in isolated liver cells

The beta-oxidation and esterification of medium-chain fatty acids were studied in hepatocytes from fasted, fed and fructose-refed rats. The beta-oxidation of lauric acid (12:0) was less inhibited by fructose refeeding and by (+)-decanoyl-carnitine than the oxidation of oleic acid was, suggesting a peroxisomal beta-oxidation of lauric acid. Little lauric acid was esterified in triacylglycerol fraction, except at high substrate concentrations or in the fructose-refed state. With [1-14C]myristic acid (14:0), [1-14C]lauric acid (12:0), [1-14C]octanoic acid (8:0) and [2-14C]adrenic acid (22:4(n - 6] as substrate for hepatocytes from carbohydrate-refed rats, a large fraction of the 14C-labelled esterified fatty acids consisted of newly synthesized palmitic acid (16:0), stearic acid (18:0) and oleic acid (18:1) while intact [1-14C]oleic acid substrate was esterified directly. With [9,10-3H]myristic acid as the substrate, small amounts of shortened 3H-labelled beta-oxidation intermediates were found. With [U-14C]palmitic acid, no shortened fatty acids were detected. It was concluded that when the mitochondrial fatty acid oxidation is down-regulated such as in the carbohydrate-refed state, medium-chain fatty acids can partly be retailored to long-chain fatty acids by peroxisomal beta-oxidation followed by synthesis of C16 and C16 fatty acids which can then stored as triacylglycerol.     

Cytostatic effect of antiestrogens in lymphoid cells: relationship to high affinity antiestrogen-binding sites and cholesterol

The antiproliferative effect of 10(-6) M antiestrogens in an estrogen receptor-negative lymphoid cell line (K36) was enhanced in lipoprotein-poor growth medium. The enhancement was not due to increased bioavailability because cellular uptake of [3H]tamoxifen was not increased and the lipoprotein fraction of serum had negligible [3H]tamoxifen-binding capacity. Cholesterol and lipoproteins, but not mevalonate, reversed the cytostatic effect of antiestrogens. Reversal by cholesterol was dose-related (10(-7) M to 10(-5) M), while that by lipoproteins could also be demonstrated in medium undepleted of lipoproteins. The cytostatic efficacy of a series of ten compounds correlated well with their relative binding affinities for solubilized antiestrogen-binding sites from K36 cells when log IC50 values (concentration required to reduce [3H]thymidine incorporation by 50%) were plotted against log RBA50 values (concentration required to reduce [3H]tamoxifen binding by 50%) (correlation coefficient 0.94). Transmission electron microscopy of antiestrogen-treated cells showed evidence of disordered cytokinesis which was partially reversed by cholesterol. These observations implicate the antiestrogen-binding protein in the antiproliferative effect of antiestrogens in nonestrogen target cells.     

Different effects of duration on prevalence of anti-adrenal medullary and pancreatic islet cell antibodies in type I diabetes mellitus

Autoimmunity is a known factor in the pathogenesis of islet cell destruction, but little is known of its role in the pathogenesis of the neuronal complications of diabetes. We carried out a cross-sectional study of 94 subjects with Type I diabetes mellitus (DM) to examine the relationship between duration and presence of complement fixing anti-adrenal medullary antibodies (CF-ADM). CF-ADM were present in 19% of subjects (n = 62) with duration of DM less than or equal to 16 years and 3% of subjects (n = 32) with duration of DM greater than 16 years. All subjects with CF-ADM+ and duration of DM 0-5 years (n = 7) were islet cell antibody positive (ICA+). Among subjects with duration of DM 6-16 years who were CF-ADM+, 4 of 5 subjects were ICA- and 1 of 5 subjects was ICA+. The only CF-ADM+ subject with duration of DM greater than 16 years was ICA-. Absorption of ADM+ and ICA+ sera with upper phase glycolipid extract blocks ICA but not ADM binding to tissue. This study suggests: 1) CF-ADM positivity is associated with ICA positivity in subjects with duration of DM 0-5 years. CF-ADM positivity persists after 5 years duration of DM when islet cell antibodies have disappeared. Therefore, the antigenic target of the adrenal medulla and pancreatic islets may be different. 2) There is an increased prevalence of CF-ADM in subjects with duration of DM 0-16 years (P less than .05).(ABSTRACT TRUNCATED AT 250 WORDS)     

Accumulation of a peptide toxin from the cyanobacterium Oscillatoria agardhii in the freshwater mussel Anadonta cygnea

Swan mussels (Anodonta cygnea) were exposed to a toxic strain of the cyanobacterium Oscillatoria agardhii. Mussels accumulated large amounts of the peptide Oscillatoria toxin which was present in low concentrations within the cyanobacterial cells in the test aquaria (40–60 µg Oscillatoria toxin/1). The toxin concentration in the mussels increased during the experiment and after 15 days of exposure the concentration was 70 ± 2 µg/g freeze dried tissue (mean ± range of values). The highest concentration of the toxin (130 µg/g of freeze dried tissue) was found in the hepatopancreatic tissue. The toxin did not seem to be metabolized in the mussels and they were not killed by the high toxin concentrations within them. After two months in clean water still detectable amounts of toxin were present in the mussels.     

Voluntary and electrically evoked strength characteristics of obese and nonobese preadolescent boys

Overweight and obese children demonstrate inferior motor performance for strength- and power-related activities requiring support or lifting of body weight. Our purpose here was to determine whether the inferior performance could be attributed to a lower strength to muscle area ratio in the obese. Eleven nonobese (16.6% fat) and 13 obese (35.5% fat) boys (9-13 years old) volunteered for the study. Peak torque was measured during voluntary isometric and isokinetic elbow flexion and knee extension at four joint angles and four velocities, respectively. The contractile properties, twitch torque, time to peak torque, and half-relaxation time were evoked for the elbow flexors by percutaneous stimulation. Elbow flexor and knee extensor cross-sectional areas (CSA) were determined by computed axial tomography taken at the mid-upper arm and mid-thigh, respectively. Isometric and isokinetic elbow flexion and knee extension strength normalized for body weight were significantly (p less than 0.05) higher in the nonobese compared to the obese boys. There were no significant (p greater than 0.05) differences, however, between groups for elbow flexor and knee extensor CSA or for absolute and relative (normalized for muscle CSA or the product of muscle CSA and height, the latter accounting for differences in moment arm length) isometric, isokinetic, or evoked twitch torque for elbow flexion or knee extension. Likewise, there were no differences between groups for the time-related contractile properties, time to peak torque, or half-relaxation time. These findings suggest that there is no difference in the intrinsic strength or contractile properties of the elbow flexor and knee extensor muscles between obese and nonobese pre-adolescent boys and that other factors, such as the handicapping effect of excess fat mass, probably account for the reduced motor performance of the obese child.     

Body surface area of Africans: a study based on direct measurements of Nigerian males

Direct measurement of body surface area (Ab) was made on 20 male adult Nigerians of African descent by coating and planimetry. The results were compared with estimated Ab values obtained using six widely accepted height and weight prediction equations. The results show that existing formulas do not predict surface areas of our subjects accurately. Measured Ab values of our subjects were 6-22% greater than predicted values obtained from non-African nomograms. Using these results, we computed new variables for height and weight formulas that accurately predict the surface area of Africans. The closest fit to measured values is given by the equation Ab(m2) = 0.001315 x Height 1.2139 (cm) x weight 0.2620 (kg) +/- 0.04815 (SEE). The new variables are significantly different from those of existing equations. Our height variable is several times greater than the weight variable and reflects a greater importance of height than weight in determining the surface area of Africans than is the case with Caucasians.     

Individualgeschichte und Gesangsauspr?gung beim Star (Sturnus vulgaris) in einer Kolonie

Zusammenfassung Die Lautäußerungen der Stare können in Gesangsstrophen und Pfeiflaute unterteilt werden. Pfeiflaute sind kurz (bis 2 s) und einfach gebaut, während die Strophen wesentlich länger andauern (meist über 20 s) und sich aus zahlreichen komplex gebauten Untereinheiten zusammensetzen. In einer Kolonie bei Frankfurt am Main, in der die Individuen durch Farbringe gekennzeichnet sind, wurde der individuelle Variationsspielraum der Lautäußerungen analysiert. In den Feinstrukturen der Pfeifthemen glichen sich die Koloniemitglieder weitgehend aneinander an. In den Feinstrukturen der Motivtypen der Gesangsstrophen traten dagegen große individuelle Unterschiede auf. , die während Jahren in der gleichen Kolonie brüteten, sangen nur sehr wenige gemeinsame Motivtypen. Die Repertoiregröße variierte zwischen 17–39 Motivtypen. Im Herbstgesang traten 5 bisher noch nicht beobachtete Motivtypen auf. Es gibt somit deutliche Hinweise darauf, daß auch der adulte Star neue Laute erlernen kann.

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Individual history and song structure of Starlings (Sturnus vulgaris) living in a colony

Summary Starling's song can be divided into warbling and whistles. Whistles have a short and simple structure, whereas warbling is sung in long sequences (most often more than 20 s). In the warbling one can distinguish many different subunits (repetition of motifs). The individual variability of songs was studied in a colony near Frankfurt/Main in West Germany, where starlings were colour banded since 1969. The following results were obtained:Birds from the same colony uttered nearly identical or very similar microstructures in the species-specific whistle themes. Different to the whistle themes very distinct individual differences characterized the warbling. Only a few motif types were common among colony members. The individual repertoire size ranged from 17 to 39 motif types. Comparison of the song of one individual between the breeding season and the following autumn shows that motifs, which were not observed during spring occurred in the autumn. This observation is a hint that starlings are capable to learn new motif types even as adults.

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Stipendium der Alexander-von-Humboldt-Stiftung     

Constitutive and interleukin-1 (IL-1)-inducible factors interact with the IL-1-responsive element in the IL-6 gene.

The interleukin-6 (IL-6) promoter is rapidly and transiently activated with other cytokines, including IL-1, tumor necrosis factor, and platelet-derived growth factor, as well as phorbol esters and agents that increase intracellular cyclic AMP. In this study, we have investigated cis-acting regulatory elements and trans-acting factors responsible for IL-1-induced IL-6 gene expression. Studies on the 5' deletion mutants of the human IL-6 gene suggested that the IL-1-responsive element was mapped within the IL-6 promoter region (-180 to -123) which was homologous to the c-fos serum-responsive enhancer element. Gel retardation assay identified two types of nuclear factors that bound to this region, one constitutive and the other inducible. These two factors recognized a 14-base-pair (bp) palindromic sequence, ACATTGCACAATCT. Furthermore, three copies of this 14-bp palindrome conferred IL-1 responsiveness to the basal enhancerless IL-6 promoter, indicating that a 14-bp-dyad symmetry sequence was an IL-1-responsive element in the IL-6 gene.     

The epsilon-subunit of ATP synthase from bovine heart mitochondria. Complementary DNA sequence, expression in bovine tissues and evidence of homologous sequences in man and rat.

The epsilon-subunit of ATP synthase from bovine heart mitochondria is assembled into the extrinsic membrane sector, F1-ATPase. The mature protein is 50 amino acid residues in length and its function is unknown. It is a nuclear gene product that is imported into the organelle. A mixture of 64 oligonucleotides 17 bases long, designed on the basis of the known protein sequence, was synthesized and used as a hybridization probe to isolate a cognate cDNA clone from a bovine library. The DNA sequence of this clone was determined, and the protein sequence of the epsilon-subunit deduced from it agrees exactly with that determined by direct sequence analysis of the protein isolated from bovine hearts. The bovine cDNA was used as a hybridization probe to examine the expression of the epsilon-subunit in various bovine tissues. mRNAs related to the cDNA are found in all of these tissues, and no evidence was obtained of the presence of mRNAs for the epsilon-subunit with similar coding sequences and dissimilar 3' non-coding regions. By hybridization experiments with digests of DNA from cow, man and rat it has been shown that sequences related to the bovine cDNA are present in the genomes of all three species. More than one related sequence was detected in all cases, indicating the presence in all three genomes of more than one gene and/or pseudogenes.     

The present level of aflatoxin in Nigerian groundnut cake ('kulikuli')

Groundnut cake ('kulikuli') purchased from four major markets in Ibadan, Oyo State, Nigeria were analysed for aflatoxin B, and associated rnycoflora. In all but two of the samples aflatoxin B, concentrations were between 20 pg/kg and 455 pg/ kg. Mould counts were low (1·0 × 10²4·40 × 10² colonies/g). Eight mould species were isolated. Of these Aspergillus niger, Paecilomyces oarioti, Aspergillus flavrs and Fusarium moniliforme dominated in decreasing sequential order. The results obtained show that groundnut cake on sale in Ibadan markets is unacceptable for animal feed rations and human consumption and there is a need for some form of quality control and decontamination before usage.