Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0038187 (starvation)
 24,951 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

As a model of cell interaction, the mating process of Oxytricha bifaria has been investigated. Mating involves several distinct and sterotyped stages, each lasting a determined time, and ending with the formation of firmly united pairs. A "waiting period" intervenes between the mixture of complimentary mating types and the onset of cell interaction. A proper starvation shortens the waiting period (25 min vs 120 min). Treatment of properly starved cells with heterologous cell-free fluid further reduces the waiting period. Certain enzyme treatments (pronase, trypsin and lipase) dramatically increase the waiting period in both washed enzyme-treated cells and in unwashed cells. Trypsin inhibits the first two stages of the mating process, while lipase inhibits membrane fusion between mates.
 ...
PMID:Conjugation in Oxytricha bifaria: cell interaction. 80 51

The compromised human newborn frequently presents with overwhelming feeding problems which lead to inadequate intake. These problems may affect the development of the small intestine, especially mucosal barrier function, leading to increased infections and susceptibility to allergens. To study this, an animal model was established using neonatal rabbits deprived of nutrients from birth until 72 h. Mucosal barrier function was compared in deprived and control (naturally fed 72-h-old animals) rabbits by measuring immunoreactive bovine serum albumin in serum 4 h after intragastric infusion of crystalline bovine serum albumin (200 mg/100 g body weight). Trypsin activity was measured in rinse fluid obtained from the small intestine. Representative sections of jejunum from control and experimental animals were formalin fixed and stained with hematoxylin and eosin for morphologic comparison. Following the bovine serum albumin feeding, a significantly increased serum immunoreactive bovine serum albumin and significantly decreased trypsin-like activity of the small intestinal rinse fluid was noted in starved animals compared to controls. In addition, the enterocytes of malnourished animals were more cuboidal and contained fewer and smaller supranuclear granules on microscopic examination than the enterocytes of controls. This study suggests that short-term starvation in newborns affects mucosal barrier function. Acute starvation may place newborns at increased risk for infections and allergic disease.
 ...
PMID:The effect of short-term starvation on mucosal barrier function in the newborn rabbit. 402 79

We measured the pools of unpolymerized and filamentous actin in homogenates of HeLa cells made in several different lysis buffers, as well as after treatment of cells with a variety of chemicals or trypsin, and after adenovirus (type 2) infection. This was possible when a series of factors concerning the basic culture conditions were kept constant: e.g., serum type used, serum batch, cell density, time after subcultivation of cells, and buffering substance in the medium. Homogenates from untreated cells usually contain 35-45 percent of the total actin in an unpolymerized form. With some batches of cells this number can be as high as 50 percent. In sparse cultures (3 x 10(4) cell/cm(2)), HeLa cells contain approximately 10 pg actin/cell, while the corresponding number is only 5 pg in dense cultures (3 x 10(5) cells/cm(2)). Treatment of cells with cytochalasin B increases the pool of unpolymerized actin by approximately 30-40 percent, while colchicine decreases the fraction of unpolymerized actin by 20 percent. The oxidant diamide increases the filamentous actin pool 25-50 percent. Glucose, sodium azide, dinitrophenol, serum starvation, or thymidine treatment does not affect the distribution between unpolymerized and filamentous actin to any significant extent. Trypsin and EDTA induced rounding up of cells but did not change the actin distribution. The distribution of actin between G- and F-forms was unchanged after adenovirus infection. These results show that significant changes in the actin pools can be induced in nucleated cells. However, several treatments which alter the morphology and motility of cells are not accompanied by an alteration in the G-/F-actin ratio.
 ...
PMID:On the dynamics of the microfilament system in HeLa cells. 680 55

The relative cell surface hydrophobicity (CSH) of 18 soil isolates of Pseudomonas fluorescens, determined by phase exclusion, hydrophobic interaction chromatography (HIC), electrostatic interaction chromatography (ESIC), and contact angle, revealed large degrees of variability. Variation in the adhesion efficiency to Macrophomina phaseolina of the hyphae/sclerotia of these isolates was also examined. Two such isolates with maximum (32.8%; isolate 12-94) and minimum (12%; isolate 30-94) CSH were selected for further study. Early- to mid-log exponential cells of these isolates were more hydrophobic than those in stationary phase, and the CSH of these isolates was also influenced by fluctuations in temperatures and pH. Isolate 12-94 exhibited high CSH (32.3%) at 30 degrees C, compared to lower values (28-24%) in the higher temperature range (35-40 degrees C). Increasing concentrations of either Zn2+, Fe3+, K+, and Mg2+ in the growth medium were associated with the increased CSH. Trypsin, pepsin, and proteinase K (75 to 150 micrograms.mL-1) reduced the CSH of isolate 12-94 cells. CSH was reduced, following exposure to DTT, SDS, Triton X-100, or Tween 80. Prolonged exposure of cells to starvation (60 days) also caused a significant decline in CSH. Several protein bands (18, 21, 23, 26 kDa) of the outer cell membrane were absent in 60-day starved cells compared to unstarved cells. In conclusion, our findings demonstrate that CSH of P. fluorescens isolates may contribute to nonspecific attachment/adhesion onto M. phaseolina hyphae/sclerotia, and the efficiency of adhesion is regulated by growth and other environmental conditions.
 ...
PMID:Influence of growth and environmental conditions on cell surface hydrophobicity of Pseudomonas fluorescens in non-specific adhesion. 1069 69

Among the prokaryotae, the nucleotide ppGpp is a second messenger of physiological stress and starvation. The target of ppGpp is RNA polymerase, where it putatively binds and alters the enzyme's activity. Previous data had implicated the beta-subunit of Escherichia coli RNA polymerase as containing a single ppGpp binding site. In this study, a photocross-linkable derivative of ppGpp, 6-thioguanosine-3',5'-(bis)pyrophosphate (6-thio-ppGpp), was used to localize the ppGpp binding site. In in vitro transcription assays, 6-thio-ppGpp inhibited transcription from the argT promoter identically to bona fide ppGpp. The thio group of 6-thio-ppGpp is directly photoactivatable and is thus a zero-length cross-linker. Cross-linking of RNA polymerase was directed primarily to the beta'-subunit and could be competed efficiently by native ppGpp but not by GTP or GDP. Cyanogen bromide digestion analysis of the cross-linked beta'-subunit was consistent with an extreme N-terminal cross-link. To assess allosteric consequences of ppGpp binding to RNA polymerase, high level trypsin resistance in the presence and absence of ppGpp was monitored. Trypsin digestion of RNA polymerase bound to ppGpp leads to protection of an N-terminal fragment of the beta'-subunit and a C-terminal fragment of the beta-subunit. We propose that the N terminus of beta' together with the C terminus of beta constitute a modular ppGpp binding site.
 ...
PMID:Binding of the transcription effector ppGpp to Escherichia coli RNA polymerase is allosteric, modular, and occurs near the N terminus of the beta'-subunit. 1103 17

The African wild cat is one of the smallest wild cats and its future is threatened by hybridization with domestic cats. Nuclear transfer, a valuable tool for retaining genetic variability, offers the possibility of species continuation rather than extinction. The aim of this study was to investigate the ability of somatic cell nuclei of the African wild cat (AWC) to dedifferentiate within domestic cat (DSH) cytoplasts and to support early development after nuclear transplantation. In experiment 1, distributions of AWC and DSH fibroblasts in each cell-cycle phase were assessed by flow cytometry using cells cultured to confluency and disaggregated with pronase, trypsin, or mechanical separation. Trypsin (89.0%) and pronase (93.0%) yielded higher proportions of AWC nuclei in the G0/G1 phase than mechanical separation (82.0%). In contrast, mechanical separation yielded higher percentages of DSH nuclei in the G0/G1 phase (86.6%) than pronase (79.7%) or trypsin (74.2%) treatments. In both species, pronase induced less DNA damage than trypsin. In experiment 2, the effects of serum starvation, culture to confluency, and exposure to roscovitine on the distribution of AWC and DSH fibroblasts in various phases of the cell cycle were determined. Flow cytometry analyses revealed that the dynamics of the cell cycle varied as culture conditions were modified. Specifically, a higher percentage of AWC and DSH nuclei were in the G0/G1 phase after cells were serum starved (83% vs. 96%) than were present in cycling cells (50% vs. 64%), after contact inhibition (61% vs. 88%), or after roscovitine (56% vs. 84%) treatment, respectively. In experiment 3, we evaluated the effects of cell synchronization and oocyte maturation (in vivo vs. in vitro) on the reconstruction and development of AWC-DSH- and DSH-DSH-cloned embryos. The method of cell synchronization did not affect the fusion and cleavage rate because only a slightly higher percentage of fused couplets cleaved when donor nuclei were synchronized by serum starvation (83.0%) than after roscovitine (80.0%) or contact-inhibition (80.0%). The fusion efficiency of in vivo and in vitro matured oocytes used as recipient cytoplasts of AWC donor nuclei (86.6% vs. 85.2%) was similar to the rates obtained with DSH donor nuclei, 83.7% vs. 73.0%, respectively. The only significant effect of source of donor nucleus (AWC vs. DSH) was on the rate of blastocyst formation in vitro. A higher percentage of the embryos derived from AWC nuclei developed to the blastocyst stage than did embryos produced from DSH nuclei, 24.2% vs. 3.3%, respectively (P < 0.05). In experiment 4, the effect of calcium in the fusion medium on induction of oocyte activation and development of AWC-DSH-cloned embryos was determined. The presence of calcium in the fusion medium induced a high incidence of cleavage of DSH oocytes (54.3%), while oocyte cleavage frequency was much lower in the absence of calcium (16.6%). The presence or absence of calcium in the fusion medium did not affect the fusion, cleavage, and blastocyst development of AWC-DSH-cloned embryos. In experiment 5, AWC-DSH-cloned embryos were transferred to the uteri of 11 synchronized domestic cat recipients on Day 6 or 7 after oocyte aspiration. Recipients were assessed by ultrasonography on Day 21 postovulation, but no pregnancies were observed. In the present study, after NT, AWC donor nuclei were able to dedifferentiate in DSH cytoplasts and support high rates of blastocyst development in vitro. Incomplete reprogramming of the differentiated nucleus may be a major constraint to the in vivo developmental potential of the embryos.
 ...
PMID:Nuclear transfer of synchronized african wild cat somatic cells into enucleated domestic cat oocytes. 1277 26

The ontogenetic development of the digestive enzymes amylase, lipase, trypsin, and alkaline phosphatase and the effect of starvation in miiuy croaker Miichthys miiuy larvae were studied. The activities of these enzymes were detected prior to exogenous feeding, but their developmental patterns differed remarkably. Trypsin activity continuously increased from 2 days after hatching (dah), peaked on 20 dah, and decreased to 25 dah at weaning. Alkaline phosphatase activity oscillated at low levels within a small range after the first feeding on 3 dah. In contrast, amylase and lipase activities followed the general developmental pattern that has been characterized in fish larvae, with a succession of increases or decreases. Amylase, lipase, and trypsin activities generally started to increase or decrease at transitions from endogenous to exogenous feeding or diet changes, suggesting that these enzymatic activities can be modulated by feeding modes. The activities of all the enzymes remained stable from 25 dah onwards, coinciding with the formation of gastric glands and pyloric caecum. These results imply that specific activities of these enzymes underwent changes due to morphological and physiological modifications or diet shift during larval development but that they became stable after the development of the digestive organs and associated glands was fully completed and the organs/glands functioned. Trypsin and alkaline phosphatase were more sensitive to starvation than amylase and lipase because delayed feeding up to 2 days after mouth opening was able to adversely affect their activities. Enzyme activities did not significantly differ among feeding groups during endogenous feeding; however, all activities were remarkably reduced when delayed feeding was within 3 days after mouth opening. Initiation of larvae feeding should occur within 2 days after mouth opening so that good growth and survival can be obtained in the culture.
 ...
PMID:Ontogenetic development of digestive enzymes and effect of starvation in miiuy croaker Miichthys miiuy larvae. 1882 Oct 26

The expressions of trypsin and chymotrypsin in the pyloric caeca of Atlantic salmon (Salmo salar L.) were studied in three experiments. Two internal (trypsin phenotypes, life stages) and three common external factors (starvation, feeding, temperatures) influencing growth rates were varied. Growth was stimulated by increased temperature and higher feeding rate, and it was depressed during starvation. The interaction between trypsin phenotype and start-feeding temperature affected specific activity of trypsin, but not of chymotrypsin. Trypsin specific activity and the activity ratio of trypsin to chymotrypsin (T/C ratio) increased when growth was promoted. Chymotrypsin specific activity, on the other hand, increased when there was a reduction in growth rate whereas fish with higher growth had higher chymotrypsin specific activity resulting in lower T/C ratio value. During a rapid growth phase, trypsin specific activity did not correlate with chymotrypsin specific activity. On the other hand, a relationship between specific activities of trypsin and chymotrypsin could be observed when growth declined, such as during food deprivation. Trypsin is the sensitive key protease under conditions favouring growth and genetically and environmentally affected, while chymotrypsin plays a major role when growth is limited or depressed. Trypsin specific activity and the T/C ratio value are shown to be important factors in the digestion process affecting growth rate, and could be applicable as indicators for growth studies of fish in captive cultures and in the wild, especially when food consumption rate cannot be measured.
 ...
PMID:Different expressions of trypsin and chymotrypsin in relation to growth in Atlantic salmon (Salmo salar L.). 2003 74

Pepsin stored in the stomach mucosa of the Atlantic salmon (Salmo salar L.) increases within two days of the onset of starvation. Trypsin and chymotrypsin in the pyloric caeca/pancreas behave similarly, indicating that when no food is present in the gut, digestive enzymes accumulate in the secretory tissues. As a corollary, trypsin and chymotrypsin activities in the gut contents fell during starvation, indicating that secretion is greatly reduced when food is not present. At the onset of feeding, pepsin is rapidly synthesised in the mucosal tissues and then secreted. Twenty four hours after feeding, the pepsin levels of the mucosa are still low, suggesting that synthesis may be a rapid response to the presence of food in the stomach. Secretion of trypsin and chymotrypsin appears to take place as soon as digesta enters the intestine, between 4 and 14h after feeding, and resynthesis of enzyme precursors appears to be complete again within a further 11h. It is suggested that both synthesis and release may be under the control of cholecystokinin.
...
PMID:The effect of feeding on the secretion of pepsin, trypsin and chymotrypsin in the Atlantic salmon,Salmo salar L. 2419 4

While technological advancements have recently led to a steep increase in genomic and transcriptomic data, and large numbers of protease sequences are being discovered in diverse insect species, little information is available about the expression of digestive enzymes in Orthoptera. Here we describe the identification of Locusta migratoria serine protease transcripts (cDNAs) involved in digestion, which might serve as possible targets for pest control management. A total of 5 putative trypsin and 15 putative chymotrypsin gene sequences were characterized. Phylogenetic analysis revealed that these are distributed among 3 evolutionary conserved clusters. In addition, we have determined the relative gene expression levels of representative members in the gut under different feeding conditions. This study demonstrated that the transcript levels for all measured serine proteases were strongly reduced after starvation. On the other hand, larvae of L. migratoria displayed compensatory effects to the presence of Soybean Bowman Birk (SBBI) and Soybean Trypsin (SBTI) inhibitors in their diet by differential upregulation of multiple proteases. A rapid initial upregulation was observed for all tested serine protease transcripts, while only for members belonging to class I, the transcript levels remained elevated after prolonged exposure. In full agreement with these results, we also observed an increase in proteolytic activity in midgut secretions of locusts that were accustomed to the presence of protease inhibitors in their diet, while no change in sensitivity to these inhibitors was observed. Taken together, this paper is the first comprehensive study on dietary dependent transcript levels of proteolytic enzymes in Orthoptera. Our data suggest that compensatory response mechanisms to protease inhibitor ingestion may have appeared early in insect evolution.
 ...
PMID:Effects of different dietary conditions on the expression of trypsin- and chymotrypsin-like protease genes in the digestive system of the migratory locust, Locusta migratoria. 2465 May 44


1