Sex differences in activation of extra-hypothalamic forebrain areas during hedonic eating

Palatable foods can stimulate appetite without hunger, and unconstrained overeating underlies obesity and binge eating disorder. Women are more prone to obesity and binge eating than men but the neural causes of individual differences are unknown. In an animal model of hedonic eating, a prior study found that females were more susceptible than males to eat palatable food when sated and that the neuropeptide orexin/hypocretin (ORX) was crucial in both sexes. The current study examined potential extra-hypothalamic forebrain targets of ORX signaling during hedonic eating. We measured Fos induction in the cortical, thalamic, striatal, and amygdalar areas that receive substantial ORX inputs and contain their receptors in hungry and sated male and female rats during palatable (high-sucrose) food consumption. During the test, hungry rats of both sexes ate substantial amounts, and while sated males ate much less than hungry rats, sated females ate as much as hungry rats. The Fos induction analysis identified sex differences in recruitment of specific areas of the medial prefrontal cortex, paraventricular nucleus of the thalamus (PVT), nucleus accumbens (ACB), and central nucleus of the amygdala (CEA), and similar patterns across sexes in the insular cortex. There was a striking activation of the infralimbic cortex in sated males, who consumed the least amount food and unique correlations between the insular cortex, PVT, and CEA, as well as the prelimbic cortex, ACB, and CEA in sated females but not sated males. The study identified key functional circuits that may drive hedonic eating in a sex-specific manner.

Multiple sclerosis patients lacking oligoclonal bands in the cerebrospinal fluid are less likely to develop neutralizing antibodies against interferon beta

Multiple sclerosis patients without cerebrospinal fluid oligoclonal IgG bands have been proposed to constitute an immunogenetically distinct subgroup of multiple sclerosis that may also differ in terms of prognosis. A proportion of patients with multiple sclerosis receiving IFNbeta develop neutralizing antibodies, which interfere with treatment efficacy. Evidence suggests that the likelihood of developing neutralizing antibodies is partly genetically determined. Here, we hypothesized that absence of oligoclonal IgG bands reflects a property of B-cell responses in oligoclonal IgG band-negative patients characterized by a lessened propensity to develop neutralizing antibodies. We aimed to compare the development of neutralizing antibodies against IFNbeta between oligoclonal IgG band-negative and oligoclonal IgG band-positive multiple sclerosis patients. Treatment, oligoclonal IgG band and neutralizing antibody information was obtained for 2219 patients from the Swedish multiple sclerosis registry and the Swedish neutralizing antibody registry. Additional data on genotype was available for 532 patients. A correlation was found between oligoclonal IgG band negativity and neutralizing antibody negativity (p = 0.02). This difference was confined to neutralizing antibodies against IFNbeta-1a, since oligoclonal IgG band-negative patients were, to a lesser extent, neutralizing antibody positive compared with oligoclonal IgG band-positive patients if treated with IFNbeta-1a (12% vs. 23%; p = 0.005). No difference was observed for IFNbeta-1b-treated patients (44% vs. 46%). We propose that oligoclonal IgG band-negative patients differ immunologically from oligoclonal IgG band-positive patients, potentially influenced by distinct HLA-DRB1 alleles.

Fatal pentastomiasis in captive African dwarf crocodile hatchlings (Osteolaemus tetraspis)

Six eggs from a captive African dwarf crocodile (Osteolaemus tetraspis) nest were artificially incubated. Two abnormal hatchlings with incomplete absorption of their yolk sacs died within 48 hr of hatching. No parasites were detected grossly or histologically in either hatchling. The remaining four apparently healthy hatchlings died without clinical signs at 3 wk of age, 1 wk after being fed live wild-caught fish and commercially raised goldfish. Necropsy revealed multiple white small wormlike organisms within the lungs, liver, and gastrointestinal tract of all four hatchlings. Histopathologic cross sections suggested that pentastomiasis was the cause of death, and whole parasites were identified as Sebekia mississippiensis. This infection was probably contracted by ingestion of live fish intermediate hosts infected with nymphal parasites. Avoiding the use of infected live fish or untreated fish products can prevent mortality of hatchling crocodilians caused by S. mississippiensis within zoological collections.

X-ray structure of the orphan nuclear receptor RORbeta ligand-binding domain in the active conformation

The retinoic acid-related orphan receptor beta (RORbeta) exhibits a highly restricted neuronal-specific expression pattern in brain, retina and pineal gland. So far, neither a natural RORbeta target gene nor a functional ligand have been identified, and the physiological role of the receptor is not well understood. We present the crystal structure of the ligand-binding domain (LBD) of RORbeta containing a bound stearate ligand and complexed with a coactivator peptide. In the crystal, the monomeric LBD adopts the canonical agonist-bound form. The fatty acid ligand-coactivator peptide combined action stabilizes the transcriptionally active conformation. The large ligand-binding pocket is strictly hydrophobic on the AF-2 side and more polar on the beta-sheet side where the carboxylate group of the ligand binds. Site-directed mutagenesis experiments validate the significance of the present structure. Homology modeling of the other isotypes will help to design isotype-selective agonists and antagonists that can be used to characterize the physiological functions of RORs. In addition, our crystallization strategy can be extended to other orphan nuclear receptors, providing a powerful tool to delineate their functions.

A CamKIIalpha iCre BAC allows brain-specific gene inactivation

We describe the generation of transgenic mouse lines expressing the Cre recombinase enzyme in brain under control of the CamKIIalpha gene present in a BAC expression vector. The CamKIIalpha BAC transgene gave a faithful expression pattern resembling the pattern of the endogenous CamKIIalpha gene. Specifically, high levels of CamKIIalpha Cre were detected in hippocampus, cortex, and amygdala, and lower levels were detected in striatum, thalamus, and hypothalamus. As expected, no expression was detected in the cerebellum or outside of the brain. The expression level of the BAC CamKIIalpha driven Cre was shown to be copy number dependent. To test the activity of the Cre recombinase, the transgenic mice were crossed with mice harbouring the CREB (cAMP response element binding protein) allele with the 10th exon flanked by two loxP sites, and recombination was monitored by the disappearance of the CREB protein. Finally, evaluation of the developmental postnatal expression of the CamKIIalpha Cre BAC revealed the expression of the Cre recombinase as early as P3.

Antioxidant status in patients with cystic fibrosis

BACKGROUND

The aim of the study was to assess the antioxidant status in cystic fibrosis (CF) patients compared to healthy controls. In order to determine the influence of nutrition on the level of the antioxidants, nutrient intake was also monitored in both groups at the time of the antioxidant assessment.

SUBJECTS AND METHODS

The authors measured the serum malondialdehyde levels in children with CF, n = 21; 9 females and 12 males, mean age: 8.71 years (6-12 years) and compared these values to the levels found in age-matched healthy control subjects, n = 24; 13 females and 11 males, mean age: 8.33 years (6-12 years). In order to assess the antioxidant status, catalase and superoxide dismutase activities in washed erythrocytes, glutathione peroxidase activity of heparinized whole blood and serum ascorbic acid, alpha-tocopherol and retinol levels were measured. Total antioxidant status (TAS) was also tested. The patients with CF received vitamin supplementation in doses prescribed in international guidelines (alpha-tocopherol: <10 years 100 mg daily, >10 years 200 mg daily, retinol: 2.5 mg daily, ascorbic acid: 100-200 mg daily).

RESULTS

Plasma levels of malondialdehyde were significantly higher (p < 0.05), superoxide dismutase activities were significantly lower (p < 0.05) in patients with cystic fibrosis. There were no significant differences in catalase, glutathione peroxidase activities and TAS levels between CF patients and control group. Plasma ascorbic acid, alpha-tocopherol and retinol levels were within normal limits in both groups.

CONCLUSION

On the basis of the present results this regime failed to provide sufficient antioxidant protection. Therefore, the authors suggest that the daily dose of these antioxidants should be either increased or to administer in parenteral route to patients with severe form of the disease.

Intestinal and blood parasites in Amazon parrots destined for relocation in Guatemala

Approximately 350 Amazon parrots were destined for relocation in Peten province, northeastern Guatemala. In random sampling of the parrots, 95 blood and 75 fecal samples were examined individually for parasites. Coccidia were present in 6.0% (3/50) of Amazona autumnalis autumnalis, and they were the only parasites detected. There were no blood parasites observed in 64 A. a. autumnalis, four Amazona pionus senilis, 16 Amazona ferinosa guatemala, 10 Amazona albifronsus albifronsus, and one Amazona xantholora. No fecal parasites were observed in four A. p. senilis, 12 A. f. guatemala, eight A. a. albifronsus, and one A. xantholora.

In vitro culture and synchronous release of Sarcocystis neurona merozoites from host cells

The growth of Sarcocystis neurona, isolate UCD1, in continuous culture was examined in 10 cell lines to identify growth conditions and methods for the preparation of parasites free of gross host cell contamination for molecular studies. The unpredictable, slow release of merozoites in most cell lines prompted development of a method to synchronously release the parasites from infected host cells. The calcium ionophore A23187 at a concentration of 1 microM was found to release intracellular merozoites with a 40 min treatment at 37 degrees C. The release of merozoites en masse from attached host cells allowed for the rapid collection of relatively pure parasites from the culture supernatant. This release of merozoites occurred in five different host cell lines. The ionophore-released parasites were highly infectious for host cells and appeared to be morphologically identical to naturally released merozoites, except that the treated merozoites had an increased number of micronemes when examined by electron microscopy. The ionophore did not enhance the release of sporozoites from sporocysts, but freezing in the presence of 5% DMSO released sporozoites that were infectious to bovine monocytes in in vitro culture.

The fall, recovery, orbit, and composition of the Tagish Lake meteorite: a new type of carbonaceous chondrite

The preatmospheric mass of the Tagish Lake meteoroid was about 200,000 kilograms. Its calculated orbit indicates affinity to the Apollo asteroids with a semimajor axis in the middle of the asteroid belt, consistent with a linkage to low-albedo C, D, and P type asteroids. The mineralogy, oxygen isotope, and bulk chemical composition of recovered samples of the Tagish Lake meteorite are intermediate between CM and CI meteorites. These data suggest that the Tagish Lake meteorite may be one of the most primitive solar system materials yet studied.

Iron status in a healthy population of Hungarian secondary school boys and girls

Iron status was assessed in a sample of 103 male and 282 female students aged from 15 to 18 years attending secondary schools in Budapest. Using a ferritin model, in boys the prevalence of iron depletion, iron-deficient erythropoiesis and iron-deficient anemia was 3.9, 2.9 and 1.0%, respectively. In girls these values were 9.6, 8.2 and 2.8%, respectively. Males had better eating habits than females. Data for nutrients intake connected with iron status are discussed. The authors recommend the improvement of iron status by dietary means and oppose the indiscriminate iron supplementation.

Ocular Onchocerca infections in two dogs in western United States

Two dogs, one from California and one from Arizona, were found to have aberrant infections caused by filarial nematodes of the genus Onchocerca. In both cases, the parasites are localized in or near the eye. In one case the worm was located in the cornea and was surgically removed. In the second case, a very marked granulomatous reaction was induced in the retrobulbar space, mimicking an abscess. This eye was enucleated. The worms in both instances were female, and were gravid, i.e. contained microfilariae in utero, indicating that a male worm(s) had been present and mating had occurred. The exact identity of the species of Onchocerca responsible cannot be determined, although the features observed are most like Onchocerca lienalis of cattle. These cases represent the fourth and fifth such cases reported from the US, and are especially interesting because of the unusual location of the worms, the small number of recognized cases, and the similarity to a recent zoonotic human infection.

Cuterebra myiasis in a group of red kangaroos (Megaleia rufa), a Bennett's wallaby (Macropus rufogriseus fruticus), and a Gunther's dik dik (Maloqua guentheri smithi)

A group of four red kangaroos (Megaleia rufa), a Bennett's wallaby (Macropus rufogriseus fruticus), and a Gunther's dik dik (Maloqua guentheri smithi) were presented over a 2-mo period with draining lesions over the thorax or on the lateral aspect of a hind leg. Only one animal exhibited more than one lesion. Physical examinations revealed infections with fly larvae. The parasites were manually removed and identified as Cuterebra spp. All of the affected animals survived, with no apparent side effects.

Opioid binding profiles of new hydrazone, oxime, carbazone and semicarbazone derivatives of 14-alkoxymorphinans

Several hydrazone, oxime, carbazone and semicarbazone derivatives of 14-alkoxycodeinones and 14-alkoxydihydrocodeinones were synthesised [1] and characterised in in vitro radioligand binding assays in rat brain membrane preparations. The tested compounds show the highest affinity for the mu opioid binding sites and most of them have agonist character. Subtype analysis of the binding shows mu2 specificity. However, some of these ligands are able to block partially (40-60%) the high affinity (putative mu1) opioid binding sites while all of them act as reversible ligands at the low affinity (putative mu2) sites.

Systematic analysis of yeast strains with possible defects in lipid metabolism

Lipids are essential components of all living cells because they are obligate components of biological membranes, and serve as energy reserves and second messengers. Many but not all genes encoding enzymes involved in fatty acid, phospholipid, sterol or sphingolipid biosynthesis of the yeast Saccharomyces cerevisiae have been cloned and gene products have been functionally characterized. Less information is available about genes and gene products governing the transport of lipids between organelles and within membranes or the turnover and degradation of complex lipids. To obtain more insight into lipid metabolism, regulation of lipid biosynthesis and the role of lipids in organellar membranes, a group of five European laboratories established methods suitable to screen for novel genes of the yeast Saccharomyces cerevisiae involved in these processes. These investigations were performed within EUROFAN (European Function Analysis Network), a European initiative to identify the functions of unassigned open reading frames that had been detected during the Yeast Genome Sequencing Project. First, the methods required for the complete lipid analysis of yeast cells based on chromatographic techniques were established and standardized. The reliability of these methods was demonstrated using tester strains with established defects in lipid metabolism. During these investigations it was demonstrated that different wild-type strains, among them FY1679, CEN.PK2-1C and W303, exhibit marked differences in lipid content and lipid composition. Second, several candidate genes which were assumed to encode proteins involved in lipid metabolism were selected, based on their homology to genes of known function. Finally, lipid composition of mutant strains deleted of the respective open reading frames was determined. For some genes we found evidence suggesting a possible role in lipid metabolism.

[Physiological role of dietary carbohydrates in diet of hungarian population. Epidemiological study]

Authors reviews--upon literature data--the metabolism of carbohydrates, with special regard to lipogenesis, which is of less importance and has no role in obesity. Out of the plasma lipids, in the case of extreme sugar consumption, only the level of triglicerides shows increase. Sugar is one but not the only factor caries. Sugar promotes the learning and remembering function of the brain and possibly, affects behaviour, too. Oligosaccharides may contribute to the favourable changes in the intestinal microflora. Carbohydrates and within them, sugars, play no unfavourable role in the development of diabetes mellitus, obesity, cardiovascular disease, when nutrition is well balanced.

Predictors of participation in prostate cancer screening at worksites

Unfortunately, African American men have a higher incidence of and a higher mortality rate for prostate cancer than White men but are less likely to participate in prostate cancer screening. This correlational survey research identifies predictors for participation in a free prostate cancer screening in 179 men, 64% of whom are African American. Each man was invited to see his personal physician for a free prostate cancer screening following a prostate cancer educational program given at his worksite. Forty-seven percent of the African American men went to their personal physician following the educational program and received a digital rectal examination (DRE) and a prostate specific antigen (PSA) screening. In the original cohort of educational program attendees, only 16% of the African Americans had obtained a DRE in the previous 12 months. However, 44% subsequently did participate in free DRE screening. Similarly, only 6% of the African American men had received a PSA screening in the previous 12 months, yet 42% obtained a PSA screening after the educational program, a sevenfold increase. Implications for allocating limited resources for education and screening to the high-risk group of African American men are discussed. This study's model of a prostate cancer educational program at worksites followed by attendees visiting their personal physician for screening could be replicated throughout the United States to increase African American men's participation in prostate cancer screening.

Pleiotropic phenotype of acetyl-CoA-carboxylase-defective yeast cells--viability of a BPL1-amber mutation depending on its readthrough by normal tRNA(Gln)(CAG)

The Saccharomyces cerevisiae gene BPL1 encodes the enzyme biotin:protein ligase (BPL), which is required for acetyl-CoA carboxylase (ACC) holoenzyme formation. Disruption of one of the two BPL1 alleles present in diploid cells results, upon sporulation, in a 2+:2(0) segregation of cell viability, with none of the two viable spores being BPL1 negative. In contrast to BPL1 deletants, BPL1 base-substitution mutants are potentially viable and may be isolated as long-chain-fatty-acid-requiring auxotrophs. In addition to ACC pyruvate carboxylase and an additional biotin-containing protein of unknown function fail to be biotinylated in BPL1-defective yeast mutants. In this study, one of these mutants, bpl1-C25/17, is shown to contain an amber stop codon at position 151 of the 689-amino-acid BPL sequence. In bpl1-C25/17 cells, de novo fatty acid synthesis is almost absent (< 2% of the wild type), while very-long-chain fatty acid (VLCFA) synthesis and, to some extent, medium-long-chain fatty acid elongation are still active. Hence, endogenous malonyl-CoA synthesis is reduced but not abolished by the translational stop mutation. A low rate of intact-BPL synthesis is accomplished in the mutant by occasional readthrough of the bpl1-C25/17 UAG nonsense triplet by normal yeast tRNA(Gln)(CAG). Correspondingly, ACC biotinylation is severely reduced though not completely absent in the two bpl1 mutants studied in this work. Residual BPL1 expression in bpl1-C25/17 cells is increased to a level allowing wild-type-like growth by transformation with high copy numbers of either the wild-type tRNA(Gln)(CAG) or the mutant bpl1-C25/17 genes. It is concluded that the lethality of BPL1 deletants is due to the lack of malonyl-CoA-dependent VLCFA synthesis and that the viability of distinct ACC-defective point mutants is due to their maintenance of a critical level of malonyl-CoA and, hence, VLCFA production. The residual capacity of malonyl-CoA synthesis, though, is inadequate to allow cytoplasmic bulk de novo fatty acid synthesis, nor does it support mutant growth on 13:0 as the only dietary fatty acid. ACC-defective mutants are respiratory deficient, which is attributed to the failure of mitochondrial fatty acid synthesis. Since lipoic acid levels of ACC1 and BPL1 mutants are essentially normal, an unknown product of mitochondrial fatty acid synthesis appears to be critically reduced in malonyl-CoA-deficient yeast cells.

Fatty acid elongation in yeast--biochemical characteristics of the enzyme system and isolation of elongation-defective mutants

Elongation of long-chain fatty acids was investigated in yeast mutants lacking endogenous de novo fatty acid synthesis. In this background, in vitro fatty acid elongation was dependent strictly on the substrates malonyl-CoA, NADPH and a medium-chain or long-chain acyl-CoA primer of 10 or more carbon atoms. Maximal activity was observed with primers containing 12-14 carbon atoms, while shorter-chain-length acyl-CoA were almost (octanoyl-CoA) or completely (hexanoyl-CoA, acetyl-CoA) inactive. In particular, acetyl-CoA was inactive as a primer and as extender unit. The Michaelis constants for octanoyl-CoA (0.33 mM), decanoyl-CoA (0.83 mM) lauroyl-CoA (0.05 mM), myristoyl-CoA (0.4 mM) and palmitoyl-CoA (0.13 mM) were determined and were comparable for fatty acid synthesis and elongation. In contrast, the affinity of malonyl-CoA was 17-fold lower for elongation (Km = 0.13 mM) than for the fatty acid synthase (FAS) system. With increasing chain length of the primer (> or = 12:0), fatty acid elongation becomes increasingly sensitive to substrate inhibition. Due to the activation of endogenous fatty acids, ATP exhibits a stimulatory effect at suboptimal but not at saturating substrate concentrations. In the yeast cell homogenate, the specific activity of fatty acid elongation is about 10-20-fold lower than that of de novo fatty acid synthesis. The same elongation activity is observed in respiratory competent and in mitochondrially defective cells. The products of in vitro fatty acid elongation are fatty acids of 15-17 or 22-26 carbon atoms, depending on whether tridecanoyl-CoA or stearoyl-CoA is used as a primer. In vitro, the elongation products are converted in part, by alpha-oxidation, to their odd-chain-length lower homologues or are hydrolyzed to fatty acids. In contrast, no odd-chain-length elongation products or very-long-chain fatty acids (VLCFA) shorter than 26:0 are observed in vivo. Hence, VLCFA synthesis exhibits a higher processivity in vivo than in the cell homogenate. In addition, the in vivo process appears to be protected against side reactions such as hydrolysis or alpha-oxidation. Yeast mutants defective in 12:0 or 13:0 elongation were derived from fas-mutant strains according to their failure to grow on 13:0-supplemented media. In vivo, 12:0 elongation was reduced to 0-10% of the normal level, while 16:0 elongation and VLCFA synthesis were unimpaired. It is concluded that yeast contains either two different elongation systems, or that the respective mutation interferes differentially with medium-chain and long-chain fatty acid elongation. The yeast gene affected in the elongation-defective mutants was isolated and, upon sequencing, identified as the known ELO1 sequence. It encodes a putative membrane protein of 32-kDa molecular mass with no obvious similarity to any of the known FAS component enzymes.

In vitro cultivation and experimental inoculation of Sarcocystis falcatula and Sarcocystis neurona merozoites into budgerigars (Melopsittacus undulatus)

This is a report of the isolation and in vitro propagation of merozoites of Sarcocystis falcatula. Culture-derived S. falcatula merozoites remained infectious after several passages in tissue culture as determined by the susceptibility of experimentally inoculated Melopsittacus undulatus that died of pulmonary sarcocystosis after experimental inoculation. There was no obvious clinical disease or lesion when Sarcocystis neurona merozoites were used to inoculate M. undulatus. On the basis of the biological infectivity data, S. falcatula and S. neurona are not synonymous as suggested from limited molecular data.

Mass changes of inositol 1,3,4,5,6-pentakisphosphate and inositol hexakisphosphate during cell cycle progression in rat thymocytes

Changes in the cellular mass and the cellular concentration of the highly phosphorylated inositol derivatives inositol 1,3,4,5,6-pentakisphosphate (Ins(1,3,4,5,6)P5) and inositol hexakisphosphate (InsP6) were observed during a complete cell cycle of proliferating rat thymocytes. Inositol polyphosphates were determined by a recently developed anion-exchange HPLC/post-column complexometric dye system (Mayr, G. W. (1988) Biochem. J. 254, 585-591), and data were expressed as mass amounts per cell number or as absolute intracellular concentrations based on cell volume determinations by the cell analyzer system CASY 1. After a very early transient rise in both Ins(1,3,4,5,6)P5 and InsP6 at the beginning of the cell cycle, a decrease of the intracellular concentration of both compounds occurred which then remained on a low level between 24 and 48 h. Between 48 and 72 h the cells divided resulting in a decrease of the cell volume by a factor of approximately 2. During this phase a pronounced increase of Ins(1,3,4,5,6)P5 and InsP6 was observed. These increases were already seen when the data were expressed as mass per cell number, but were even enhanced when expressed as absolute intracellular concentrations. In conclusion, we present as a novel finding long term changes in the intracellular concentrations of Ins(1,3,4,5,6)P5 and InsP6 in proliferating thymocytes. This may indicate a role for these compounds during cell cycle progression.

The role of the Crabtree effect and an endogenous fuel in the energy metabolism of resting and proliferating thymocytes

Rat thymocytes have been used to characterize the changes in energy metabolism that occur as cells undergo a resting/proliferation transition. In the resting state, anaerobic ATP production accounts for only 4% of ATP turnover. The remainder is fueled by the oxidation of a mixture of an unidentified endogenous fuel (62%), glucose (18%) and glutamine (16%). 48 h after mitogen stimulation, the ATP turnover has increased twofold. In these proliferating cells, glucose inhibits oxygen consumption by 58%, indicating a profound Crabtree effect which is not present in resting cells. Consequently, proliferating cells, in the presence of glucose and glutamine, fuel the majority (61%) of ATP turnover anaerobically, producing lactate from glucose. The development of a Crabtree effect may be the result of the 8-10-fold increase in glycolytic enzyme activities which occurs with proliferation. Possible advantages of such a proliferative metabolism are a sparing of endogenous fuel, and a minimizing of oxidative metabolism, with its concurrent production of free radicals.

Cell cycle-associated expression of M2-type isozyme of pyruvate kinase in proliferating rat thymocytes

During a complete cell cycle of rat thymocytes stimulated by concanavalin A and interleukin 2, the activity and mRNA level of pyruvate kinase reached a maximum (8-12-fold increase) 48 h after stimulation coinciding with the S-phase of the cell cycle. Increases of cellular enzyme activity, pyruvate kinase protein, and mRNA levels are correlated up to 48 h of culture. Afterwards pyruvate kinase activity and mRNA levels decrease, whereas the pyruvate kinase protein continues to increase throughout mitosis. This change of specific pyruvate kinase activity points to a posttranslational modification of the enzyme besides its transcriptional regulation. The presence of the M2-type isozyme was determined by the following methods: (a) native cellulose acetate electrophoresis and activity staining, (b) Northern blot hybridization with M1- and M2-specific cDNA probes, and (c) determination of kinetic parameters. The isozyme pattern did not change during the cell cycle progression. The induction of pyruvate kinase is completely abolished by 2-difluoromethylornithine-mediated polyamine depletion. However, the proportion of hybridizable pyruvate kinase mRNA was not affected. These data suggest the requirement of polyamines for efficient translation rather than transcription during cell growth.

[The effect of soybean protein on lipids and trace elements in elderly hospitalized women]

Institutionalized elderly women received 5 g/day soya supplementation for three months. After having finished the soya supplementation, serum cholesterol levels of hypercholesterolemic women decreased and serum zinc levels were lower in all examined persons, compared to the status of the initiation of dietetic intervention.

Cytotoxic effects of alkyl-lysophospholipids in human brain tumor cells

The cytostatic activity of alkyl-lysophospholipids (ALP) was investigated in vitro with cells from 2 astrocytomas, 2 glioblastomas and a meningioma. In all lines the incorporation of [3H]thymidine into the tumor cells was inhibited by ALP. This effect was dependent on the ALP dose and incubation time. Incorporation rates were less than 5-10% of the control rates after an incubation time of more than 48 h with the ALP compound at a concentration of 20 micrograms/ml. 2-lysophosphatidylcholine, the ester-linked lysophospholipid, did not reveal any cytostatic effects. As a morphological criterion for severe cell damage, the trypan blue dye exclusion test was performed. Results were closely correlated with those of the thymidine incorporation inhibition assay. Further morphological evidence for actual damage of the tumor cell, caused by ALP incubation, was obtained by light microscopy of cytocentrifuge preparations and scanning electron microscopy. Membrane defects of tumor cells incubated with ALP were observed both in light and scanning electron microscopy, whereas untreated control cells remained intact. In cytocentrifuge smears of tumor cells, karyorrhexis occurred after 24 h of ALP treatment. After 48 h the cells looked almost completely damaged, and only fragments remained. Microvilli, blebs and ruffles, which indicate high surface activity and are characteristic morphological features of neoplastic astroglial cells in scanning electron microscopy, were severely disturbed by ALP incubation. Finally, the ability of tumor cells to adhere to glass and plastic surfaces was affected.

Amebiasis in red-footed tortoises

Of 500 red-footed tortoises imported to southern Florida, approximately 200 died during a 2-month period. Clinical signs were nonspecific and included anorexia, listlessness, and watery diarrhea, with lingering death. Necropsy consistently revealed thickened duodenum, with necrotic mucosa and multifocal to diffuse areas of hepatic necrosis. Histologic evaluation of tissues demonstrated numerous amebae in intestinal and hepatic lesions.

Cytotoxicity of alkyl-lysophospholipid derivatives and low-alkyl-cleavage enzyme activities in rat brain tumor cells

Alkyl-lysophospholipids (ALP) and related derivatives inhibited the in vitro incorporation of [3H]thymidine into seven different permanent cell lines derived from rat brain tumors. The cytostatic effect of ALP was dependent on dosage and incubation time. Naturally occurring 2-lysophosphatidylcholine did not exhibit cytostatic effects; under these conditions, the incorporation rates of [3H]thymidine were generally more than 100% of the controls. The trypan blue dye exclusion test, which was used to assess severe cell damage, correlated with the extent that [3H]thymidine incorporation was inhibited by ALP. Preincubation of ALP (rac-1-octadecyl-lyso-glycero-3-phosphocholine) for more than 8 min with a tetrahydropteridine-dependent O-alkyl cleavage enzyme preparation from rat liver microsomes destroyed almost all of the cytotoxic properties of ALP when tested at a concentration that previously inhibited tumor growth by more than 50%. [3H]Thymidine incorporation rates were greater than 100% for astrocytoma cells incubated with ALP after exposure to the alkyl cleavage enzyme. Comparison of the microsomal activities of the tetrahydropteridine-dependent alkyl-cleavage enzyme present in astrocytoma 78-FR-G-299 cells and the pleomorphic glioma 78-FR-G-219/S4 cells to that found in normal skin fibroblasts and rat livers revealed a markedly reduced activity in the neoplastic cell lines. Moreover, those tumor cells that were more resistant to ALP cytotoxicity (pleomorphic glioma, 78-FR-G-219/S4) had a 3-fold higher tetrahydropteridine-dependent cleavage activity than a more cytotoxic sensitive line (astrocytoma cells, 78-FR-G-299). Our results indicate that the low-alkyl-cleavage enzyme activities in these neoplastic cells in comparison to normal cells might be a factor in explaining the relatively high cytotoxicity of ALP in tumor cells.

Purification of human monocytes by adherence to polymeric fluorocarbon. Characterization of the monocyte-enriched cell fraction

Human mononuclear cells were obtained from peripheral blood by density gradients. Monocytes can be purified after cultivation of 2 hours by a modified adherence procedure on membranes of gas-permeable polymeric fluorocarbon (teflon). After further cultivation of 24-48 hours, monocyte-enriched cell fraction can be easily detached from the membranes with a viability greater than 98% and a final cell yield of approximately 50% of the peripheral monocyte count. The cells showed the morphological and cytochemical characteristics of human monocytes and differentiated into dense monolayers of macrophages within 10 days of cultivation. Immune-autoradiography with iodine-125-labelled xenogeneic antimonocytic antisera and staining with several monoclonal antisera in an indirect immunofluorescence technique revealed up to 92% of these cells to carry monocytic characteristics. To show their functional integrity, monocytes obtained by this procedure were activated by 48 hours' cultivation with synthetic alkyl-lysophospholipids to inhibit the proliferation of autologous tumor cells.

[Postoperative total parenteral feeding with a carbohydrate mixture (autor's transl)]

After gastric operations, patients were fed completely by the parenteral route. Aminoacids, caloric nutrients and electrolytes were infused simultaneously and continuously 24 hours daily until the fourth postoperative day. The daily supply of aminoacids amounted to 80 g. Glucose, fructose and xylite in equal proportions were used to supply calories. The total daily amount was 605 g. The important electrolytes were contained in the infusion solutions in amounts corresponding to basic requirement. The results of the investigation confirmed that patients can be successfully nourished parenterally after extensive operations with the combined daily additives we have selected.

[Behavior of the metabolism in gastric patients during a 4-day-long postoperative complete parenteral feeding with amino acids and a glucose-levulose-xylitol combination solution]

In a clinical study we tested the following parameters: free fatty acids, beta-hydroxybutyrate, acid-base-balance, lactate, bilirubin, uric-acid, fructose, xylitole, glucose in blood and urine. The tests were executed in 9 patients who were undergoing stomac operations. The cardio pulmonary system of all patients was normal, and there was a homeostasis in water and electrolytes preoperatively. In combination with the amino-acids we received a ratio of 1:1:1 for glucose, levulose and xylitole. Totally, the patients received 0.36 g per kg body weight and per hour of carbohydrates. Beta-hydroxybutyrate, aceto-acetat, and free fatty acids show normal values under conditions of parenteral nutrition as well as lactate, uric acid, and acid-base-balance. The ratio of the different carbohydrates in serum and urine prove that the infusion time and volume were extremely favourable. The loss of carbohydrates in urine was very low.

[Metabolic behavior in total parenteral nutrition during the postoperative phase]

In patients who had undergone gastric operation, total postoperative parenteral nutrition was effected using a combination of two infusion solutions having complementary constituents. 80 g L-amino acids and about 2,500 kcal in the form of a glucose-levulose-xylitol mixture together with electrolytes and trace elements were infused daily. Metabolic parameters, serum levels and the concentrations of the most important administered substances excreted in the urine were determined every day at the same time. The 1:1:1 glucose-levulose-xylitol ratio of the caloric carrier proved to be a favourable combination with respect to metabolic behaviour and the necessary daily supply of calories. The basic electrolyte requirement of the patients was to a large extent met by the quantities contained in the solutions.

Stoffwechselverhalten bei totaler parenteraler Ernährung in der postoperativen Phase

Bei magenoperierten Patienten wurde eine postoperative totale parenterale Ernährung mit einer Kombination zweier sich in ihrer Zusammensetzung ergänzender Infusionslösungen durchgeführt. Täglich wurden 80 g L-Aminosäuren, zirka 2500 kcal in Form eines Glukose-Lävulose-Xylit-Gemisches sowie Elektrolyte und Spurenelemente infundiert. Stoffwechselparameter, Serumspiegel und Urinausscheidung der wichtigsten zugeführten Substanzen wurden täglich zum gleichen Zeitpunkt bestimmt. Die Relation der Kalorienträger Glukose: Lävulose: Xylit = 1:1:1 erwies sich dabei als günstige Kombination in bezug auf Stoffwechselverhalten sowie notwendige tägliche Kalorienzufuhr. Der Basisbedarf der Patienten an Elektrolyten wurde durch die in den Lösungen enthaltene Menge weitgehend gedeckt.