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PubMed1998

Regulated expression of neurogenic basic helix-loop-helix transcription factors during differentiation of the immortalized neuronal progenitor cell line HC2S2 into neurons.

Expression of nine neurogenic basic helix-loop-helix (bHLH) transcription factors was examined in an immortalized neuronal progenitor cell line HC2S2, which differentiates into neurons after suppression of the v-myc expression with tetracycline. Expression of MASH-1, NeuroD, NeuroD-related factor (NDRF) and HES-1 was demonstrated in HC2S2 cells by Northern blot analysis using total RNA. Expression of MASH-1 mRNA was downregulated upon differentiation of HC2S2 cells into mature neurons. In contrast, NeuroD and NDRF mRNA expression was maintained all through the differentiation. The expression of HES-1, a negative regulator of the neuronal differentiation, was upregulated temporarily in accordance with the suppression of the v-myc expression and was downregulated upon the differentiation of HC2S2 cells into neurons. The reduced expression of HES-1 mRNA in undifferentiated HC2S2 cells may be explained by the transcriptional suppression of HES-1 by the myc oncoprotein. The above data imply that both HES-1 and MASH-1 need to be downregulated at the time of accomplishment of the terminal differentiation into mature neurons and that NeuroD and NDRF participate in the regulatory process of the terminal differentiation in combination.

Animals↗
PubMed1993

Radiofrequency lesions of the PVN fail to modify the effects of serotonergic drugs on food intake.

Past research has suggested that the paraventricular nucleus (PVN) of the hypothalamus is an important brain site mediating changes in feeding induced by drugs that modify 5-hydroxytryptamine (5-HT; serotonin) neurotransmission. To test this possibility, several experiments examined the impact of lesions of the PVN on both decreases and increases in feeding following treatment with 5-HT-acting drugs. Rats with free access to standard lab chow were given access also to a wet mash diet for 1 h each day. When intakes of this diet had stabilised, rats were divided into two groups: one group received bilateral radiofrequency lesions of the PVN, the other served as a sham-operated control group. The PVN-lesioned group consumed more lab chow and gained significantly more weight over a 10-week period than the control group. Clonidine stimulated feeding in the sham-operated group, but did not do so in the lesioned group. These findings confirmed that the PVN lesions disrupted the control of food intake, as well as body weight regulation. The indirect 5-HT agonists D-fenfluramine (0.63, 1.25 and 2.5 mg/kg) and fluoxetine (2.5, 5 and 10 mg/kg), and the 5-HT1 agonist 1-(m-trifluoromethylphenyl)piperazine (TFMPP, 0.63, 1.25 and 2.5 mg/kg) dose dependently reduced the intake of the wet mash diet in sham-operated animals. This action was not modified by the PVN lesions. The highest doses of D-fenfluramine and fluoxetine also suppressed intake of chow over the 23-h period subsequent to the wet mash presentations, but the magnitude of this effect was similar in sham-operated and PVN-lesioned animals.(ABSTRACT TRUNCATED AT 250 WORDS)

8-Hydroxy-2-(di-n-propylamino)tetralin↗
PubMed1991

Low doses of the 5-HT1A receptor agonist 8-OH-DPAT increase ingestive behavior in late preweanling and postweanling, but not neonatal rat pups.

Late preweanling (postnatal day 17-18; P17-18) and postweanling (P28-29) Sprague-Dawley rat pups were tested in the presence of both mash and liquid diets following s.c. administration of 0, 0.03, 0.06, 0.1 or 0.5 mg/kg of the 5-HT1A receptor agonist 8-hydroxy-2(di-n-propylamino)tetralin (8-OH-DPAT). Preweanling pups exhibited both a low dose stimulatory and high dose depressant effect of 8-OH-DPAT on mash-related ingestive behaviors, whereas postweanling rat pups were less sensitive to 8-OH-DPAT, exhibiting only an increase in mash ingestion within the dose range examined. In contrast, when neonatal (P3-4) rat pups were tested with milk across a dose range of 0.001-1.0 mg/kg 8-OH-DPAT, no increases in ingestion were seen, with lower doses in this range having no detectable effects and higher doses decreasing ingestion and mouthing. To the extent that low doses of 8-OH-DPAT increase feeding via preferential stimulation of 5-HT1A autoreceptors, these data suggest that neonates may lack functional 5-HT1A autoreceptors, with these receptors maturing by the late preweanling period.

8-Hydroxy-2-(di-n-propylamino)tetralin↗
PubMed1988

The "turning off" of excessive cell replicative activity in advanced atherosclerotic lesions of swine by a regression diet.

We studied progression of atherosclerotic lesions in the coronaries and abdominal aortas of swine fed hyperlipidemic (HL) diets producing serum cholesterol levels of about 700 mg/dl for up to 18 months with killings at 9, 13.5 and 18 months on diet. We studied changes in lesions in subsets given after 9 months on the HL diet a low fat, low cholesterol mash diet with killings at 4.5 and 9 months on the regression diet. Lesion cell numbers were evaluated using mean nuclear profiles per cross-section (Np/Cx) in an anatomically defined portion of artery as an index. Lesion sizes were evaluated using mean cross-sectional area (area/Cx) as an index. Tritiated thymidine labeling indices (LI) were used as an index of cell proliferative activity in the coronaries. We also determined the percentage of lesions occupied by lipid rich calcific necrotic debris. For further comparisons all of the same values were determined for normal intimal cell masses (ICM) in control groups fed a low fat, low cholesterol mash diet throughout. The atherosclerotic lesions in the HL swine appeared to arise mainly in the ICM. These became lesions and increased tremendously in size and cell numbers. The greatest increase was in the abdominal aorta even when lesion values were normalized by being expressed as percentages of the wall (intima + media). Lipid-rich calcific necrotic debris occupied about 25% of the lesion by 9 months and the percentage was similar at 18 months although size of lesions and their necrotic regions had increased 3-fold over the 9-month interval. Lesion [3H]thymidine LIs were 3-4-fold greater than in the control ICM. In the period 9-18 months on an HL diet lesions increased about 3-fold in size and cell numbers. In the swine put on a regression diet for the 9-18 month period growth of the lesions stopped completely. In fact, there was a numerical decrease in lesion sizes and cell numbers and this was statistically significant for the left anterior descending coronary. The lesion growth stoppage was partly accounted for by the "turning off" of excessive DNA synthesis activity of the lesion cells as indicated by the return of [3H] thymidine LIs to the normal values in the mash controls. Another factor was the lack of increase and in fact marked reduction in the size of the regions of lipid rich necrotic debris.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1982

Responses to dietary adulterations in rats with zona incerta lesions.

Large lesions of the rostral zona incerta (ZI) permanently reduced food and water intake and body weight to about 75% of control levels. When quinine hydrochloride was added to the water supply, the experimental animals exhibited a somewhat greater initial decrease in fluid consumption, but otherwise responded much like control rats to quinine adulteration of both food and water. The ZI animals reduced their fluid intake when water was added to the food supply, in the form of wet mash, while the controls showed no compensation for the auxiliary water. When presented with sucrose solutions, the ZI animals increased their fluid intake, but reduced their mash consumption, to a greater degree than control rats. The experimental animals also showed an exaggerated response in both food and caloric intake to the addition of sucrose to the wet mash.

Animals↗
PubMed1990

The use of 3H standards in 125I autoradiography.

To avoid repeated production of 125I tissue mash standards and to decrease inter-experiment variability, a set of commercially available, high activity plastic 3H standards was calibrated for use with 125I autoradiographs. Standards with a range of 2.0-7390 microCi 3H/g plastic were used since they produced autoradiographs of suitable optical density (darkness) at exposure times of 4 to more than 72 h. Tissue mash standards at 12 concentrations of 125I were produced by homogenizing rat brains and adding 125I. These were frozen and sectioned at thicknesses ranging from 6 to 120 microns and mounted on microscope slides. Each set of tissue standards, along with slides bearing the plastic 3H standards, was opposed to film for various times. The calibration of the 3H standards was done separately for each time point and section thickness. Autoradiographs were analyzed using a computer assisted image analysis system. The standard curve generated for each set of 125I-labelled tissue standards was correlated with the 3H standards. It was found that the relationship between the 3H plastic standards and the 125I tissue mash standards was not simple and depended on exposure time, thickness of the section, as well as the concentration of radioactivity in a given standard. However, this accurate calibration of the 3H standards yields long-lived standards for 125I autoradiography useful over a wide range of radionuclide concentrations, tissue thicknesses and exposure times.

Animals↗
PubMed1981

Tolerance of adult mallards to subacute ingestion of crude petroleum oil.

Adult male mallards were fed untreated mash or mash containing 1.5% Prudhoe Bay crude oil for 7 days ad lib. During the initial 24 h of exposure to crude petroleum oil, ducks consumed less mash (P less than 0.05) and lost approx. 3.5% of their initial body weight (P less than 0.05), however, neither intake nor body weight differ between groups on days 2-7. Plasma samples collected between 09.00 and 10.00 h on days 0, 1, 3, or 7 indicated that corticosterone, glucose, thyroxine, total protein, and uric acid concentrations, and the activities of aspartate aminotransferase (AST), alanine aminotransferase (ALT), and butyrylcholinesterase (BCHE) were not affected by treatment. These findings suggest that adult mallards may be able to tolerate large quantities of crude petroleum oil mixed in their diet (approx. 25 ml over a 7-day period) without overt or biochemical indications of distress.

Animals↗
PubMed1999

Influence of temperature shifts on survival, growth, and toxin production by psychrotrophic and mesophilic strains of Bacillus cereus in potatoes and chicken gravy.

A study was done to determine the influence of temperature on growth and toxin production characteristics of psychrotrophic and mesophilic strains of Bacillus cereus when inoculated into mashed potatoes and chicken gravy containing various concentrations of sodium chloride and held at temperatures different from those at which cells had been cultured. Logarithmic growth phase cells (10 h, 30 degrees C) of psychrotrophic (F3802A/84) and mesophilic (B4ac-1) strains of Bacillus cereus were inoculated into rehydrated commercially processed instant mashed potatoes and chicken gravy supplemented with 0, 2, or 4% sodium chloride. Growth, survival, and diarrheal toxin production in potatoes and gravy held at 30, 37, and 10 degrees C (strain F3802A/84) or 30, 40, and 10 degrees C (strain B4ac-1) were monitored. Both strains grew in both foods containing no added sodium chloride or 2% sodium chloride when held at 30, 37, or 40 degrees C for 2 days. Strain B4ac-1 grew better than strain F3802A/84 in foods containing 4% sodium chloride. Maximum amounts of enterotoxin (1024 ng/g) were produced by strain B4ac-1 in chicken gravy held at 30 and 40 degrees C. Strain F3802A/84 grew to populations of 7 log10 CFU/g in foods containing no added sodium chloride or 2% sodium chloride at 10 degrees C. Strain F3802A/84 produced the highest amount of enterotoxin (1024 ng/g) at 30 degrees C in chicken gravy containing 0.7 or 2% sodium chloride; however, little or low amounts of toxin (4-16 ng/g) were produced in chicken gravy at 10 degrees C. Compared to strain B4ac-1, cells of strain F3802A/84 subjected to a downward shift in incubation temperature (10 degrees C) grew more rapidly in chicken gravy. Strain B4ac-1 produced the highest amount of toxin (1024 ng/g) at 30 degrees C in gravy containing 4% sodium chloride and at 40 degrees C in gravy containing 0.7% sodium chloride. Toxin was not detected in inoculated mashed potatoes. Results of this study indicate that shifts in incubation temperature influence growth and toxin production by psychrotrophic and mesophilic strains of B. cereux differently. It is important to store pasteurized, ready-to-eat foods at a temperature low enough to prevent the growth of B. cereus.

Animals↗
PubMed1988

Rates of eating by domestic fowls in relation to changing food deficits.

Rates of eating by immature female fowls declined in a curvilinear way in the 30 min after return of food after 0-4 h deprivation. Amounts eaten in the first 5-10 min were related positively to the length of deprivation and were greater with pelleted food than with mash. Times taken by birds to reach a presumed equilibrium between probabilities of feeding starting and stopping, at two consecutive minutes with less than 0.2 g eaten, were related positively to the deprivation period and were greater with mash than with pellets. At these times, however, more had been eaten with pellets than with mash, and none of the deprived birds had eliminated their estimated food deficits. Furthermore, in only one out of ten treatments did birds compensate imbalances completely by the end of the 90 min test. It is proposed that the observed changes in eating rate may reflect interactions between pecking success, increasing fatigue and decreasing hunger. It is also concluded that, while short-term adjustments in feeding may be limited by preabsorptive factors, eventual compensation of imbalances depends on postabsorptive control.

Animals↗
PubMed2003

Some histologic and biochemical evidence for mitigation of cyanide-induced tissue lesions by antioxidant vitamin administration in rabbits.

The effect of antioxidant vitamins on cyanide-induced tissue damage was investigated in New Zealand White rabbits using a combination of colorimetric, spectrophotometric, enzymatic, gravimetric and histological methods. Three groups of rabbits (six per group) were used in a 4-week feeding experiment. One group received pure grower's mash, while a second group was fed mash containing 400 ppm inorganic cyanide. The third group received daily oral doses of vitamins A, C and E, in addition to mash and 400 ppm cyanide. There were significant decreases (P < 0.05) in activities of superoxide dismutase (SOD), catalase and alkaline phosphatase (AP) in the liver, lung and kidney of the two groups given cyanide, but the decreases were significantly lower (P < 0.05) in the group fed antioxidant vitamins. In addition, the antioxidant vitamin supplementation led to marked reductions in the severity of histopathological degeneration in these tissues. These results strongly suggest that cyanide-induced tissue lesions may be relieved by adequate intake of antioxidant vitamin supplements.

Animals↗
PubMed1980

Production of oxytetracycline by Streptomyces rimosus 12,907 as an animal feed supplement.

Production of oxytetracycline by Streptomyces rimosus 12907 as an animal feed supplement was achieved with a fermentation medium, containing the following ingredients (g/litre): black strap molasses, 30; fodder yeast, 20; rice bran, 10; KH2PO4, 0.2; and tap water to 1,000 ml. The dry mash, containing oxytetracycline, was 50 g/litre of fermentation medium. The amount of oxytetracycline, present in the dry mash, was about 4.0%. The dry mash, containing oxytetracycline, contained the following amino acids: L-arginine, L-histidine, L-lysine, L-isoleucine, L-leucine, L-phenylalanine, Dl-methionine, and L-tryptophan.

Amino Acids↗
PubMed2003

Increased ethyl caproate production by inositol limitation in Saccharomyces cerevisiae.

Sake mash was prepared using rice with polishing ratios of 70%, 80%, 90% and 98%. At a polishing ratio of 70%, the highest amounts of ethyl caproate were produced in sake mash, and supplementation of inositol caused a decrease in ethyl caproate production. However, at a polishing ratio of over 90%, supplementation of inositol had no effect on ethyl caproate production. These results suggest that the use of rice with a polishing ratio of 70% results in increased ethyl caproate content in sake when limiting the inositol available to yeast. The reduction in ethyl caproate production following inositol addition was due to the decrease in its enzymatic substrate caproic acid, because the concentrations of middle chain fatty acids (MCFA), caproic acid, caprylic acid and capric acid in sake were lowered by inositol. A disruptant of the OPI1 gene, an inositol/choline-mediated negative regulatory gene, produced higher amounts of MCFA than the control strain both in the static culture and in sake mash when a sufficient amount of inositol was supplemented. Therefore, the enhancement of MCFA biosynthesis by inositol limitation was thought to be caused not by a posttranscriptional event, but predominantly by transcriptional enhancement of fatty acid biosynthetic genes. The overexpression of FAS1 considerably stimulated MCFA formation while that of ASC2, ACC1 and FAS2 genes was not effective. Co-overexpression of FAS1 and FAS2 resulted in a maximal stimulation of MCFA formation and substantially abolished the inhibitory effect of inositol on MCFA formation. These results suggest that the repression of FAS1 gene expression by inositol results in the decrease in MCFA formation. Therefore, it is presumed that the removal of inositol by polishing the rice used in sake brewing, increases the production of ethyl esters of MCFA, since high-level production of MCFA is achieved by the derepression of FAS1 transcription.

Journal Article↗
PubMed1988

Rodents' (Rattus, Mesocricetus, and Meriones) use of learned caloric information in diet selection.

When given a choice between two mashes of equal caloric density but differing flavors, rats (Rattus norvegicus) show a robust preference for the flavor previously associated with a higher calorie food. This finding suggests that rats may identify food quality by sensory cues such as taste. Our initial attempt to show this effect in the golden Syrian hamster (Mesocricetus auratus) failed, apparently because of this species's tendency to store both high- and low-calorie mashes in their cheek pouches during conditioning trials. Initially we attempted to circumvent this seeming morphological constraint on learning by presenting low- and high-calorie mashes on alternate days. This procedure too failed to produce evidence of flavor-caloric learning, although this procedure produced robust learning in another rodent, the Mongolian gerbil (Meriones unguiculatus). Another method of preventing cheek pouching--concurrently presenting low- and high-calorie liquid diets--was more successful; then, hamsters showed clear evidence of flavor-caloric learning. Thus, although flavor-caloric learning is demonstrable in species of rodent besides the rat, the circumstances under which it occurs vary.

Animals↗
PubMed2001

Determination of PAH in food samples by HPLC with fluorimetric detection following sonication extraction without sample clean-up.

A rapid method is proposed for the determination of 16 polycyclic aromatic hydrocarbons (PAH) in non-fatty food (mashed potato, potato and toasted bread samples) based on their extraction with ethyl ether-methylene chloride (1:1) by sonication, and subsequent separation by high-performance liquid chromatography (HPLC) with fluorimetric detection. A Hypersil Green PAH column was used with a gradient of acetonitrile-water as the mobile phase, together with a programme of ten excitation and emission wavelength pairs. At levels 1.60-2320 microg kg(-1), mean recoveries of PAH were in the range 70-86% for mashed potato, potato and toasted bread samples. The relative standard deviations were in the range 4.2-11% (n = 6). Total PAH found in mashed potato were in the range 9.35-17.1 microg kg(-1), in potato samples 8.47-17.2 microg kg(-1) and in toasted bread samples 7.38-18.0 microg kg(-1), with relative standard deviations in the range 0.8-12%. Only chrysene, determined in Ortiz toasted bread (7.38 microg kg(-1)), has carcinogenic properties.

Bread↗
PubMed1994

Removal of residual yolk at hatch influences food choice and feeding activity in lines of chickens selected for high or low juvenile body weight.

The effect of residual yolk removal at hatch on growth and feeding behavior was assessed in lines of chickens divergently selected for low (LW) or high (HW) 56-day body weight. At hatch chicks were assigned to 1 treatment: removal of the residual yolk (R) or no surgery (I). Twenty-four chicks per line (12 I and 12 R) were assigned to an all-mash regimen (M) and 48 per line (24 I and 24 R) to a choice (C) between mash and dietary residual yolk. HW were heavier than LW chicks regardless of treatment. On day 5 and thereafter, chicks given a choice were heavier than those eating mash. HW chicks ate more than LW ones. The percentage of yolk eaten increased during the 2-3 d after hatch, remained constant for 2 d, then decreased. Results are discussed in term of yolk need and development of the gastrointestinal tract in the divergent lines.

Animal Feed↗
PubMed2005

Assessment and amelioration of hyperacusis in tinnitus patients.

CONCLUSIONS: Tinnitus can be bothersome even without hyperacusis. The good correlation found in this study between the multiple-activity scale for hyperacusis (MASH) score and the overall annoyance of hyperacusis score supports the reliability of self-rating of hyperacusis. Objectives. A prospective study was undertaken to investigate the relationships between hyperacusis and tinnitus and to determine whether hyperacusis can be rapidly controlled over time. MATERIAL AND METHODS: All tinnitus patients seen over a period of 16 months with surnames beginning with the letters A L (n = 249) were assessed during a structured interview using (i) a scale ranging from 0 to 10 for assessing the annoyance of tinnitus and the overall annoyance of hyperacusis and (ii) the newly introduced MASH. RESULTS: The annoyance of tinnitus was greater in females. The prevalence of hyperacusis was high (79%). The annoyance of hyperacusis varied. Patients were categorized into five groups according to the hyperacusis annoyance score, as follows: no hyperacusis; mild hyperacusis (< or = 3); moderate hyperacusis (3.1-5.0); substantial hyperacusis (5.1-7.0); and severe hyperacusis (> or = 7.1). Individuals with severe hyperacusis were younger than those in the other groups. The correlation between the annoyance of tinnitus and the annoyance of hyperacusis was poor (r = 0.35). No audiometric difference was found between categories, whereas self-rated hearing deficiency increased with the annoyance of hyperacusis. A good correlation (r = 0.89) was found between the overall annoyance of hyperacusis and the MASH score. Changes over time, assessed in 32 patients investigated at least 3 times, showed more frequent improvement in hyperacusis (63%) than tinnitus (47%).

Adult↗
PubMedDate not supplied

Effect of low level of dietary aflatoxins on baladi rabbits.

Aflatoxins B1, B2, G1 & G2 were administered in a low concentration (100 ppb of each aflatoxin (AN] in a mash offered to Baladi rabbits. An other group of rabbits were fed on the same contaminated mash in addition to 0.25% charcoal (CC). The two groups were compared to control animals fed on AN-free mash. Inclusion of AN in the diet decreased feed and water consumption, body weight and survival rate. Charcoal improved somewhat feed and water consumption and growth rate than AN-group. However, CC-group affected digestibility of organic matter more than AN-group. Relative weights of liver, kidneys, heart and adrenal glands were significantly higher in AN and CC groups than the control group. Blood haemoglobin content, packed cell volume percentage and sedimentation rate were lower in AN group. Although there were an increase in each of serum, calcium, inorganic phosphorus, cholesterol, phospholipids and glutamic-pyruvic transaminase in AN group, yet the serum nitrogen and glutamic-oxalacetic transaminase were reduced. Charcoal had alleviated AN-effects concerning N, GPT and phospholipids. Chemical analysis revealed elevation of water, ash and silica contents of liver and water content of muscles from AN-animals. On the other hand, fat content, GOT and vitamin A in the liver as well as muscles ash were reduced. Addition of CC to the diet reduced AN-effects on liver fat, ash and silica but resulted in a rise of the water content of liver and muscles and liver GPT activity. Charcoal also resulted in a sharp decrease in vitamin A content of the liver. Aflatoxin treatments (in AN and CC groups) reduced bone ash, silica and magnesium as well as bone volume. Charcoal administration increased Ca-content of bones. Aflatoxin feeding (in AN group) resulted in a high residual percentage of AN in muscles, serum, liver, heart and kidneys with relationships of 51 :24 : 3 :2 : 1, respectively. Only 1.42% of the fed AN was excreted in the faeces. Charcoal usage had a good effect as it prevented AN to accumulate in the organs. Aflatoxin contaminated diets (in AN and CC groups) resulted in paralysis, disorder of fat deposition, discolouration and haemorrhages of some organs. Scanning electron microscopic examination revealed no ill effect on the surface structure of the small intestine due to either AN or AN + CC. Pathological examination showed that the main affected organs were liver, heart and spleen, respectively. The changes include hepatic round cell infiltration, irregularities of lobular plats, focal necrosis and periportal fibrosis.(ABSTRACT TRUNCATED AT 400 WORDS)

Adsorption↗
PubMedDate not supplied

A test for passive absorption of glucose in yellow-rumped warblers and its ecological implications.

In an earlier study, we found that yellow-rumped warblers had in vitro active uptake rates of D-glucose that were only a few percent of the glucose absorption rate achieved at the whole-animal level. Here we used a pharmacokinetic technique to test whether a substantial amount of sugar can be absorbed passively. We used yellow-rumped warblers (Dendroica coronata), known for their seasonal frugivory, freely feeding on a synthetic mash formulated with naturally occurring concentrations of D-glucose. Birds absorbed 89.8% +/- 1.0% (SE) of the D-glucose in the mash. When fed the same mash with trace-labeled 3H L-glucose, the stereoisomer that does not interact with the intestinal Na(+)-glucose cotransporter, 3H appeared in plasma, an indication that this stereoisomer of glucose was absorbed. We used 3H levels in plasma and excreta in a pharmacokinetic model to calculate L-glucose extraction efficiency (i.e., the percent absorbed). Calculated mean extraction efficiency for the passively absorbed L-glucose averaged 91% +/- 23%. Our finding of considerable passive absorption reconciles the in vitro and in vivo results for D-glucose absorption and is in concert with results from five other avian species. The passive pathway appears to provide birds with an absorptive process that can respond quickly to changing luminal concentration and that is energetically inexpensive to maintain and modulate in real time but that may bear a cost. Less discriminate passive absorption might increase vulnerability to toxins and thus constrain foraging behavior and limit the breadth of the dietary niche.

Absorption↗