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Early posthatch starvation induces myonuclear apoptosis in chickens.

The effect of early posthatch starvation on myonuclear apoptosis was examined in chickens. Male broiler chickens were or were not provided feed for the first 3-d posthatch. Subsequently, all chickens were provided feed for an additional 4-d posthatch. Chickens were killed at 3- and 7-d posthatch, and the pectoralis thoracicus was harvested, fixed and embedded in paraffin. Muscle sections were labeled with the terminal deoxynucleotidyl transferase histochemical staining technique to identify apoptotic nuclei. At 3- and 7-d posthatch, there was a significantly (P < 0.05) smaller myofiber cross-sectional area for the starved compared with the fed chickens. A larger proportion (P < 0.05) of apoptotic nuclei relative to total nuclei was observed in the starved compared to the fed chickens killed at 3-d posthatch, but the proportion of apoptotic nuclei relative to total nuclei did not differ (P > 0.05) between the starved and fed chickens killed at 7-d posthatch. It appears that apoptosis is a mechanism contributing to the smaller myofiber size observed when feed is not provided early posthatch.

Animals↗

Mucin dynamics in the chick small intestine are altered by starvation.

The absorptive surface of the small intestine is covered by a layer of mucus secreted by goblet cells. The secreted mucins and thickness of the adherent layer influence nutrient digestion and absorption processes as well as the functionality of the mucosa. In this study, methods for the analysis of mucin synthesis and dynamics in the chick small intestine are described. A fragment of chicken mucin cDNA was isolated and characterized; this fraction had 60% homology to human mucin MUC-5AC. The thickness of the mucus adherent layer and the relative amounts of mucin glycoprotein and mRNA were also examined in the small intestines of control and starved chicks. Relative amounts of intestinal mucin mRNA and protein increased in the duodenum and jejunum of starved chicks, and mucus adherent layer thickness decreased throughout the small intestine. In starved chicks, higher mRNA expression and protein concentrations with lower amounts of adherent mucus may be related to a higher rate of degradation of the mucus layer, a lower rate of mucus secretion, or an altered rate of mucin turnover. It thus appears that starvation alters mucus dynamics in the small intestine, and this may affect intestinal digestive function and defense.

Amino Acid Sequence↗

Protein in the food prolongs DNA synthesis in the liver of rats after starvation.

After a period on protein-free diet and then starvation, high protein diet induces DNA synthesis in rat liver for a longer period than diet containing an equivalent amount of amino acids. The requirement for high protein diet is limited to an early part of the prereplicative period and administration of the high protein diet later did not prolong DNA synthesis.

Amino Acids↗

Homicide by starvation.

Homicide by starvation is a very rare occurrence, especially when the victim is ambulant. This paper presents a case where the death of the individual went undiscovered for more than 3 weeks. A successful conviction for murder ensued. The paper also discusses social and pathological problems associated with this crime.

Child, Preschool↗

Gut hormones in preterm infants with necrotizing enterocolitis during starvation and reintroduction of enteral nutrition.

OBJECTIVES: Gastrointestinal hormones control gut functions in response to enteral nutrition. Diseases involving the gastrointestinal tract, such as necrotizing enterocolitis, may affect gut hormone secretion and therefore influence gut functions. Because bowel rest is an important part of the treatment, infants with this disease are especially at risk for an altered gut hormone secretion and thus for compromised gut functions. METHODS: In the current study, the gastrointestinal hormone profiles of eight preterm infants with an ileostomy after necrotizing enterocolitis (Bell stages 2 and 3) were evaluated during starvation and reintroduction of enteral nutrition. Basal and postprandial plasma concentrations of gastrin, cholecystokinin, and peptide YY were measured with sensitive and specific radioimmunoassays. The results were compared with those of 11 controls. RESULTS: In the patients and the controls, plasma concentrations of all hormones were higher postprandially. The increases in cholecystokinin and peptide YY were significant in the patients. Compared with the controls, all concentrations were higher in the patients, and changes were significant for basal and postprandial cholecystokinin and postprandial peptide YY. CONCLUSIONS: Enteral nutrition stimulates the secretion of gastrointestinal hormones, also in premature infants with a diseased distal small bowel and colon, as in necrotizing enterocolitis. The postprandial increase of peptide YY in patients with an ileostomy indicates that enteral substrate in the colon is not necessary for stimulation of peptide YY secretion.

Cholecystokinin↗

A comparison of the effects of skeletal trauma and surgery on the ketosis of starvation in man.

The increase of plasma ketone bodies (acetoacetic acid and beta-hydroxybutyric acid) is related to the efficient protein-sparing adaptation during a total fast by healthy man. This study investigated the response to a total fast during the postinjury state. Twenty patients with skeletal or soft-tissue trauma received 3 days of carbohydrate-free intake and then 3 more days of carbohydrate intake. Control subjects were ten postoperative patients and two healthy volunteers who received similar nutritional treatment. The trauma patients lost nearly 20 gm of nitrogen/day, which was twice control, and had a resting energy expenditure of 27.07 kcal/kg, 21.4% greater than controls. Trauma was found related to an elevation in plasma glucose and to inhibit the rise in plasma ketone bodies and free fatty acids. In contrast, indirect calorimetry showed that fat contributed 63% of the nonprotein energy on the third day of fasting and injury. These data indicate that fat is utilized by the trauma patient but that fatty metabolism is abnormal compared to starvation in healthy or mildly stressed patients.

Acetoacetates↗

Cobalt starvation affects multiple cellular processes in Desulfofundulus kuznetsovii TPOSR during alcohol oxidation.

Cobalt influences the methanol metabolism of Desulfofundulus kuznetsovii TPOSR, specifically by modulating the activity of one of its alcohol dehydrogenases (ADH), Adh1. However, the effects of cobalt on the broader proteome of strain TPOSR, as well as the utilization of alcohols besides methanol, remain unexplored. Here, proteomic analyses of strain TPOSR grown with and without cobalt on different alcohol substrates show that cobalt starvation impacts multiple cellular processes, including cobalamin biosynthesis, iron-sulphur cluster assembly and, most prominently, energy metabolism as indicated by altered abundances of hydrogenases and NAD(P)-dependent oxidoreductases. Despite the presence of six ADH-encoding genes in the genome, Adh1 is the dominant ADH during growth not only on methanol but also on several primary alcohols and diols (ethanol, 1-propanol, 1,2-propanediol, 1,3-propanediol, butanol, pentanol and heptanol). Enzymatic assays with purified Adh1 confirm activity with these substrates, except 1,3-propanediol, and show no activity toward secondary alcohols (2-propanol and 2-butanol). Comparative proteomics analyses of other sulphate-reducing microorganisms (SRMs), namely Desulfofundulus australicum and Solidesulfovibrio carbinolicus, further indicate that methanol and ethanol oxidation in SRMs is mediated by a single ADH/AOR pair. Together, these findings highlight the central role of cobalt in alcohol metabolism in strain TPOSR and identify conserved ADH/AOR enzymes as promising candidates for biotechnological applications.

Cobalt↗

Marrow cell necrosis in anorexia nervosa and involuntary starvation.

Marrow specimens from six patients with anorexia nervosa and three with involuntary starvation were examined for the presence of gelatinous transformation and marrow cell necrosis. Five of the patients had pancytopenia. Acanthocytes were present in the circulation of all nine. In only two patients was marrow cellularity adequate. Gelatinous transformation was present in every marrow specimen and was of a marked degree in eight. Marrow cell necrosis was identified in all nine marrow specimens. The necrosis was extensive in one specimen, focal in the others and limited to the areas of gelatinous transformation. Severe malnutrition was the single element common to all the patients.

Acanthocytes↗

The effect of starvation on the susceptibility of teneral and non-teneral tsetse flies to trypanosome infection.

Transmission of vector-borne diseases depends largely on the ability of the insect vector to become infected with the parasite. In tsetse flies, newly emerged or teneral flies are considered the most likely to develop a mature, infective trypanosome infection. This was confirmed during experimental infections where laboratory-reared Glossina morsitans morsitans Westwood (Diptera: Glossinidae) were infected with Trypanosoma congolense or T. brucei brucei. The ability of mature adult tsetse flies to become infected with trypanosomes was significantly lower than that of newly emerged flies for both parasites. However, the nutritional status of the tsetse at the time of the infective bloodmeal affected its ability to acquire either a T. congolense or T. b. brucei infection. Indeed, an extreme period of starvation (3-4 days for teneral flies, 7 days for adult flies) lowers the developmental barrier for a trypanosome infection, especially at the midgut level of the tsetse fly. Adult G. m. morsitans became at least as susceptible as newly emerged flies to infection with T. congolense. Moreover, the susceptibility of adult flies, starved for 7 days, to an infection with T. b. brucei was also significantly increased, but only at the level of maturation of an established midgut infection to a salivary gland infection. The outcome of these experimental infections clearly suggests that, under natural conditions, nutritional stress in adult tsetse flies could contribute substantially to the epidemiology of tsetse-transmitted trypanosomiasis.

Aging↗

The quormone degradation system of Agrobacterium tumefaciens is regulated by starvation signal and stress alarmone (p)ppGpp.

A unique signal degradation system has recently been discovered in Agrobacterium tumefaciens. Upon entering stationary phase, A. tumefaciens terminates quorum sensing-dependent Ti-plasmid conjugation by degradation of acyl homoserine lactone (AHL) quormone via the enzyme AttM (AHL-lactonase). attM, together with attK and attL, constitute one transcriptional unit subjected to the control of a common promoter. AttJ, the other member of the signal degradation system, is an IclR-like negative transcriptional factor, which tightly represses the expression of AttM at the early stage of bacterial growth. In this study, we found that this quormone degradation system is activated by either carbon or nitrogen starvation. Quormone degradation was significantly delayed when bacterial culture was supplemented with extra carbon or nitrogen source in the nutrient-limited minimal medium before the onset of stationary phase. To identify the signalling pathway and regulatory mechanisms that mediate quormone degradation, we constructed a reporter strain A6(attKLM::lacZ) in which the promoterless lacZ was transcriptionally fused to the attKLM promoter. Transposon mutagenesis of strain A6(attKLM::lacZ) led to identification of the relA gene, which encodes the stress alarmone (p)ppGpp synthetase. Tn5 knock-out of relA abolished the stationary phase-dependent expression of attM. We concluded that the A. tumefaciens quormone degradation system is coupled to and regulated by the generic (p)ppGpp stress response machinery.

4-Butyrolactone↗

Entry of mRNA into polyribosomes during recovery from starvation in mouse sarcoma 180 cells.

Starvation in mouse sarcoma 180 cells leads to a block in initiation of protein synthesis which results in the conversion of polysomes to 80-S ribosomes. The mRNA is released as nucleoprotein particles. Addition of nutrients to the starved cell causes the rapid uptake of the mRNA into large polysomal structures. The ribosomes enter these structures more gradually, without much effect on the sedimentation profile of the labeled mRNA. The results indicate that the stored mRNA in starved cells is readily available for uptake into polysomes. They also suggest that the mRNA may be binding to components other than ribosomes during the initial stages of polysome formation.

Animals↗

Gelatinous transformation of bone marrow in prolonged self-induced starvation.

In bone marrow from 3 patients with prolonged, severe self-induced starvation, fat atrophy, hypoplasia of haemopoietic cells and characteristic gelatinous transformation of marrow were noted. The gelatinous substance appeared amorphous and stained pink with the Wright-Giemsa stains. Histochemical and ultrasturctural studies indicated that it consisted of acid mucopolysaccharides and was extracellular in nature. Similar marrow abnormalities were produced in rabbits by limitating their food intake for 4 months. These marrow abnormalities in the experimental animals could be reverted to normal by restoring their nutritional status. It is proposed that the gelatinous transformation of marrow is caused by excessive production of mucopolysacchrides of the ground substance to compensate for the mobilization of marrow fat which occurs to meet the energy requirement. It is further postulated that excessive production of acid mucopolysaccharides may provide a microenvironment unsuitable for haemopoietic proliferation. The relevance of these findings to other conditions associated with marrow aplasia, is discussed.

Animals↗

Starvation triggers the delivery of the endoplasmic reticulum to the vacuole via autophagy in yeast.

Autophagy is a survival mechanism necessary for eukaryotic cells to overcome nutritionally challenged environments. When autophagy is triggered, cells degrade nonselectively engulfed cytosolic proteins and free ribosomes that are evenly distributed throughout the cytoplasm. The resulting pool of free amino acids is used to sustain processes crucial for survival. Here we characterize an autophagic degradation of the endoplasmic reticulum (ER) under starvation conditions in addition to cytosolic protein degradation. Golgi membrane protein was not engulfed by the autophagosome under the same conditions, indicating that the uptake of ER by autophagosome was the specific event. Although the ER exists in a network structure that is mutually connected and resides predominantly around the nucleus and beneath the plasma membrane, most of autophagosome engulfed ER. The extent of the ER uptake by autophagy was nearly identical to that of the soluble cytosolic proteins. This phenomenon was explained by the appearance of fragmented ER membrane structures in almost all autophagosomes. Furthermore, ER dynamism is required for this process: ER uptake by autophagosomes occurs in an actin-dependent manner.

Autophagy↗

Medical assessment of adolescent girls with eating disorders: an evaluation of symptoms and signs of starvation.

AIM: To investigate the prevalence of symptoms and signs related to starvation at the initial examination of adolescent girls with eating disorders (ED). METHODS: Two hundred and eleven girls with eating disorders recruited for a multicentre research and evaluation programme of six specialist eating disorder services in Sweden have been studied. The presence or absence of 12 symptoms, reported by the patients, and 16 signs, observed by the examiners, were registered and related to body weight. RESULTS: Eleven observed signs--loss of subcutaneous fat, loss of muscle mass, loss of muscular force, dry and scaly skin, brittle nails, dry and brittle hair, lanugo hair, resting pulse <60, systolic blood pressure <110, peripheral hypothermia, and peripheral cyanosis--were related to body weight expressed in standard deviation scores (SDS). When the number of observed signs for each patient was calculated, there was a strong relationship with weight. The odds ratio for having more than two signs was 4.35 (95% CI 2.67-7.04; p = 2.8 x 10(-9) for every one-unit change in weight SDS. Of the symptoms reported by the patients, only three were related to weight. When the number of reported symptoms for each patient was calculated, a relationship with weight was not observed. CONCLUSION: In adolescent girls with ED, physical signs observed at medical examination can be related to weight. However, reported symptoms are poorly related to weight and may be influenced by other factors. The finding emphasizes the importance of medical assessment at presentation of patients with ED.

Adolescent↗

Action spectrum for sporulation and photoavoidance in the plasmodium of Physarum polycephalum, as modified differentially by temperature and starvation.

The plasmodium of the myxomycete Physarum polycephalum sporulates in bright natural environments, suggesting a relationship between photobehavior and sporulation. Thus, the action spectra for two light-dependent phenomena as well as the effects of other environmental conditions have been studied. Sporulation like photo-avoidance responded to UVC (near 270 nm) and near IR (near 750 nm) in addition to the well-documented UVA (near 350 nm) and blue (near 460 nm) regions. Sporulation and photoavoidance had similar sensitivities in the shorter wavelengths, while the former was about 100 times more sensitive in near IR. The plasmodium moved away from light in a wide spectral range. Starvation and high temperature at 31 degrees C (25 degrees C in standard conditions) reduced photoavoidance to UVA and to blue light, respectively. A high fluence rate of UVC suppressed the rhythmic contraction of the plasmodium, and the action spectrum peaked at 270 nm. These results indicate that the Physarum plasmodium may stay at brighter places not by positive phototaxis but by weakening the negative phototaxis to sunlight or by other possible taxes such as hydrotaxis. There may be at least four different photo-systems in the plasmodium.

Animals↗

Enhanced electrogenic secretion in vitro by small intestine from glucagon-treated rats: implications for the diarrhoea of starvation.

Glucagon treatment of fed rats (50 micrograms I.P. every 6 h for 3 days) induces significant increases in vitro of the basal short-circuit currents of the jejunum (52%) and proximal ileum (81%) and in their electrogenic secretory responses to stimulation by bethanechol, a muscarinic agonist. The results support a role for glucagon in the intestinal hypersecretion observed in starvation and nutrient deprivation.

Animals↗

Starvation in human pregnancy: hypoglycemia, hypoinsulinemia, and hyperketonemia.

In women fasted during the second trimester of pregnancy, concentrations of glucose and insulin in the plasma fell to a greater extent and ketone acid concentrations in the blood rose more rapidly than in nonpregnant controls. Nitrogen excretion in the urine, particularly ammonia, was increased in the pregnant group. Continuous glucose utilization by the conceptus may exaggerate and accelerate the metabolic consequences of starvation.

Blood Glucose↗