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Query: UMLS:C0011570 (depression)
 172,036 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Polyethylene glycol (PEG) has been used to increase the osmotic pressure of fluids used to cleanse the gastrointestinal tract. However, little is known about its osmotic activity. To investigate this activity systematically, solutions of PEG of differing molecular weights were made and subjected to measurement of osmolality by both freezing point depression and vapor pressure osmometry. Measured osmolality was increasingly greater than predicted from average molecular weight as PEG concentration increased. Measurement of sodium activity in NaCl/PEG solutions by means of an ion-selective electrode suggested that the higher than expected osmolality could be due in part to interactions that, in effect, sequestered water from the solution. Osmolality was consistently greater by freezing point osmometry than by vapor pressure osmometry. To determine which osmometry method reflected biologically relevant osmolality, normal subjects underwent steady-state total gut perfusion with an electrolyte solution containing 105 g/L of PEG 3350. This produced rectal effluent that was hypertonic by freezing point osmometry but isotonic by vapor pressure osmometry. Assuming that luminal fluid reaches osmotic equilibrium with plasma during total gut perfusion, this result suggests that the vapor pressure osmometer accurately reflects the biologically relevant osmolality of intestinal contents. We conclude that PEG exerts more of an osmotic effect than would be predicted from its molecular weight. This phenomenon may reflect interactions between PEG and water molecules that alter the physical chemistry of the solution and sequester water from the solution.
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PMID:Osmotic effects of polyethylene glycol. 334 95

The effects of the adrenal inhibitor trilostane were examined in male and female rats to determine whether growth rate could be improved by lowering circulating plasma corticosterone concentrations. Dose-response studies revealed that in young female rats (125 g) trilostane lowered peak plasma corticosterone levels in a dose-dependent manner. In male rats plasma corticosterone concentrations were reduced only by very high doses of trilostane (200 mg/kg), while lower doses (2-8 mg/kg) actually increased them. Five growth studies were conducted using a total of 90 rats. In female animals, daily injections of trilostane (10 mg/day) caused an age-dependent increase in growth rate ranging from 11% in 127 g rats to 30% in 164 g rats. In three out of four experiments using females, food intake was slightly increased by the drug. Food conversion efficiency was improved consistently by trilostane by up to 18%. Trilostane-treated females had significantly heavier adrenal glands and livers, but lighter kidneys than control rats. When a complete carcass analysis was performed on one experimental group, no significant differences were found. Carcass component weights relative to control values were: body weight (103%), body water (105%), fat-free solids (103%), carcass weight (103%), body length (103%), body fat (95%) and gut content (96%). In male rats (160 g), daily injections of trilostane (10 mg) resulted in a steady and sustained depression of growth rate reflecting a similar fall in food intake, with no change in food conversion efficiency. It is concluded that in older female rats growth rate is constrained by physiological concentrations of glucocorticoids.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Age- and sex-dependent stimulation of growth rate in rats by the adrenal inhibitor trilostane. 347 83

P. equorum is a common and ubiquitous parasite that persists for many years in stables and on pasture in spite of good hygiene and anthelmintic control programs. Foals are usually infected early in life. During the migratory phase of the infection, clinical signs include coughing and a nasal discharge followed by depression and unthriftiness as the worms mature in the gut. Some foals die as a result of intestinal impaction or rupture. Patency is established around 3 months of age, and fecal egg counts may rise to very high levels. From 6 months of age onwards, the ascarid burden diminishes as the foals become immune. Patent infections are seldom found in mature horses and, when present, they tend to be of low magnitude. Preventive measures are aimed at treating foals frequently enough to prevent the development of a large mass of ascarids in the intestine. This is achieved by a 6-weekly dosing regimen using an anthelmintic with proven and reliable efficacy against P. equorum.
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PMID:Ascarids. Recent advances. 352 75

Animals filled almost to satiation by nonnutritive bulk do not satiate when they ingest a small amount of seaweed. This suggests that satiation is not triggered by chemostimulation of an anteriorly located "hot spot." Inflation of a balloon placed in the gut of the animal results in satiation as reflected in a number of different parameters of feeding behavior. The suppressive effect of a relatively brief inflation is rapidly and fully reversible, although repeated inflation and deflation appeared to produce slowly reversible or irreversible effects. The parameters of the changes in feeding during gut inflation are comparable to those of normal animals that are slowly fed individual pieces of food. The inflation volume needed to satiate the animal is a function of the rate of inflation--more rapid inflations requiring larger volumes. Cutting of the esophageal nerves results in a significant increase in the volume needed to satiate the animals, but nevertheless they eventually cease feeding and generally do not show a burst gut. The evidence indicates that the satiation that eventually occurs in nerve-sectioned animals, at least in part, is due to depression of feeding following very prolonged sensory stimulation. The data suggest that for a rapidly consumed meal, satiation results primarily due to distension-related gut signals conveyed by the esophageal nerves, whereas for very slowly consumed meals, the former factor interacts with a process associated with sensory stimulation, such as receptor adaptation. The current results indicate that balloon distension can serve as a reasonable stimulus in experiments in simplified preparations in which the nervous system can be studied.
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PMID:Mechanisms underlying satiation of feeding behavior of the mollusc Aplysia. 367 21

Although it is highly desirable to reduce the need for experiments with animals, in vitro methods cannot entirely supplant them. Observations made in simple systems must be checked in a live subject if they are to be relevant to man or other higher animals. Young growing chicks are very susceptible to vitamin deficiencies. Biological assays in chicks have been used to check the validity of chemical and microbiological methods of measuring vitamins in foods. Experiments with chicks and chick embryos deprived of vitamin B12 have served to predict the likely clinical effects of analogues of the vitamin. The discovery of the growth-promoting properties of dietary antibiotics stimulated research into the influence of the gut microflora on its host. Studies in germ-free and gnotobiotic chicks have implicated Streptococcus faecium as one of the organisms responsible for the growth depression reversed by antibiotics. In general the growth of conventional chicks given adequate diets is slightly less good than that of their germ-free counterparts, although small beneficial effects of the microflora have been observed in special circumstances. The most important function of the indigenous microflora appears to be as a barrier against invasion by pathogens. To sustain this protective barrier may incur a small cost to the host in terms of dietary energy and other nutrients.
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PMID:Gordon memorial lecture. The biologists' debt to the domestic fowl. 370 5

Left ventricular function and systemic regional blood flow (radioactive microspheres, 15 +/- 5 mu) were studied 1, 3, 10 or 42 days after left coronary occlusion in conscious rats. One day after coronary occlusion, vascular resistance in the skeletal muscle and cutaneous beds increased while stroke work and left ventricular systolic pressure were depressed. Regional blood flow and hemodynamic data were similar for sham and infarction groups at 3 and 10 days after surgery, except for left ventricular end-diastolic pressure, which was significantly increased in rats with infarction (sham versus infarct: 11.5 +/- 1.0 versus 18.4 +/- 3.2 at day 3 and 12.2 +/- 1.4 versus 19.9 +/- 3.2 at day 10) (p less than 0.05). At 42 days after myocardial infarction, manifest heart failure occurred as documented by decreased cardiac output and left ventricular systolic pressure and elevated left ventricular end-diastolic pressure and vascular resistance in the cutaneous, skeletal muscle and renal beds. In a separate group of animals with moderate (33.2 +/- 2% of left ventricle) and large infarctions (45 +/- 1.3% of left ventricle), regional blood flow was compared with the sham group. Rats with a large infarct demonstrated significant (p less than 0.05) reduction in flow to kidney, gut and liver. In rats with a medium sized infarct, only renal blood flow was significantly reduced. It is concluded that in this model of myocardial infarction, early cardiocirculatory depression is followed by a partially compensated state with increased left ventricular end-diastolic pressure and subsequent systemic and regional vasoconstriction which, in turn, may contribute to late deterioration of heart failure.
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PMID:Regional vascular adjustments during recovery from myocardial infarction in rats. 371 8

Acute hypoxia is known to cause a marked reduction in intestinal and peripheral blood flow, in favor of blood flow to the brain and heart. Complete occlusion of the intestinal circulation is known to damage the gut wall, allowing potentially lethal endotoxins present within the intestines to escape into the circulation. We examined here whether the breathing of a hypoxic gas mixture could lead to sufficient damage of the intestinal wall to cause endotoxemia. Six anesthetized monkeys breathed air for 1 hr, then an hypoxic mixture (FIO2 = 0.13) containing N2O for 1 h and, finally, 100% O2. Plasma endotoxin concentrations were determined by two methods. After approximately 40 min of hypoxia, the plasma endotoxin level rose significantly from 0.39 to 1.60 ng X ml-1 (p less than 0.001) and then subsided to near control levels. Control monkeys breathing air only or 70% N2O in oxygen (FIO2 = 0.3) for 3 h showed no such elevation in plasma endotoxin concentration. We conclude that hypoxia leads to a temporary endotoxemia in primates. Reticuloendothelial system depression by whole body X-irradiation (200 rads) increased both the magnitude and duration of the hypoxia-induced endotoxemia. Prior administration of equine anti-lipopolysaccharide (anti-LPS) hyperimmune plasma greatly reduced the magnitude of the induced endotoxemia. Since endotoxemia may be lethal, the use of anti-LPS as possible prophylaxis should be considered in persons breathing artificial atmospheres or where acute hypoxia may be a danger.
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PMID:Hypoxia-induced endotoxemia in primates: role of reticuloendothelial system function and anti-lipopolysaccharide plasma. 379 22

We have studied 22 consecutive patients referred for investigation of severe chronic right upper quadrant pain. The majority were women whose symptoms had been present for many years. All had undergone repeated investigations of the pancreatico-biliary, gastro-intestinal, urinary, and even gynaecological systems without a satisfactory diagnosis. Most had undergone at least one abdominal operation in an unsuccessful attempt to cure their pain. In 21 of 22 patients the customary pain was completely and reproducibly mimicked by balloon distension of the small or large intestine in at least one site. The trigger sites were jejunum (15), ileum (12), right colon (nine), and duodenum (six). In 12 more than one trigger site was found. Close questioning revealed features of the irritable bowel syndrome in the majority and depression in many though the symptoms were not spontaneously volunteered. Reproduction of pain has provided a convincing demonstration to this difficult group of patients that they have a sensitive gut and allows appropriate management.
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PMID:Origin of chronic right upper quadrant pain. 401 43

1. Stimulation of the vagal non-adrenergic inhibitory innervation caused the release of adenosine and inosine into vascular perfusates from the stomachs of guinea-pigs and toads.2. Stimulation of portions of Auerbach's plexus isolated from turkey gizzard caused the release of adenosine triphosphate (ATP), adenosine diphosphate (ADP) and adenosine monophosphate (AMP).3. ATP, added to solutions perfused through the toad stomach vasculature, was broken down to adenosine, inosine and adenine.4. Of a series of purine and pyrimidine derivatives tested for inhibitory activity on the guinea-pig isolated taenia coli, ATP and ADP were the most potent.5. ATP caused inhibition of twelve other gut preparations previously shown to contain non-adrenergic inhibitory nerves. The inhibitory action of ATP was not prevented by tetrodotoxin.6. Quinidine antagonized relaxations of the guinea-pig taenia coli caused by catecholamines or adrenergic nerve stimulation. Higher concentrations of quinidine antagonized relaxations caused by ATP or non-adrenergic inhibitory nerve stimulation.7. When tachyphylaxis to ATP had been produced in the rabbit ileum, there was a consistent depression of the responses to non-adrenergic inhibitory nerve stimulation but not of responses to adrenergic nerve stimulation.8. It is suggested that ATP or a related nucleotide is the transmitter substance released by the non-adrenergic inhibitory innervation of the gut.
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PMID:Evidence that adenosine triphosphate or a related nucleotide is the transmitter substance released by non-adrenergic inhibitory nerves in the gut. 2788 76

It has been shown that cis-platinum-induced nephrotoxicity in rats can be inhibited by diethyldithiocarbamate (DDC). We report here the bone marrow protective properties of DDC in hybrid (C57BL X BALB/c) mice exposed to single and fractionated doses of cis-platinum. Relatively nontoxic doses of DDC afford maximum protection, using that dose of cis-platinum that would result in the death of 50% of the mice within 9 days as an end point (dose-limiting gut toxicity in mice), when injected 0.5 to 2 hr following i.p. cis-platinum treatment. Survivals of colony-forming units in spleen, nucleated bone marrow cells, and peripheral white blood cell were used to assess the bone marrow protective properties of DDC following both single and fractionated doses of cis-platinum. A dose modification factor of 3.2 (based on colony-forming units in spleen survival) was obtained when DDC (1000 mg/kg) was injected into mice 0.5 hr after graded doses of cis-platinum. When fractionated doses of cis-platinum were used (6 mg/kg on Days 0, 10, 20, and 30), the survival of colony-forming units in spleen was markedly enhanced if the animals were rescued with DDC 0.5 hr following each cis-platinum dose. When bone marrow cellularity was measured immediately before and 2 days after each dose of cis-platinum, a similar pattern of depression and recovery was noted whether DDC was present or not; however, the depression was less marked in mice rescued with DDC. When peripheral white blood cell counts were monitored, the nadir and recovery were similar in the presence or absence of DDC; however, recovery occurred sooner in the animals that had received DDC. Our data support the ability of DDC to modify the bone marrow toxicity of cis-platinum in normal mice. Experiments are in progress in tumor-bearing animals exploring the differential protection afforded by DDC between bone marrow and tumor.
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PMID:Modification of the bone marrow toxicity of cis-diamminedichloroplatinum(II) in mice by diethyldithiocarbamate. 633 56


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