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Query: UMLS:C0344329 (collapse)
 28,634 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Acid-base balance during development of diabetic ketoacidosis was reappraised on the basis of old studies on urinary excretion of ions. Circulatory collapse with impaired urinary excretion of acids is a prominent feature of the late phase of diabetic ketoacidosis, in which pathophysiological measurements are difficult to make. To elucidate the balance between hepatic uptake of carboxylic acids (free fatty acids and lactate plus pyruvate) and hepatic release of carboxylic acids (ketone bodies and lactate plus pyruvate) during the late phase of diabetic ketoacidosis, perfused livers from normal and streptozotocine-diabetic rats, fasted for 48 h, were subjected to high perfusate glucose concentrations, low perfusate pH and low perfusate flow rates. Provided that flow was kept normal, there was always a net uptake of carboxylic acids. At normal flow, a low pH and a high glucose concentration in the perfusate did not affect the hepatic uptake of lactate plus pyruvate or the flux of carbon from lactate to glucose. Reduction of the perfusate flow rate by two-thirds invariably turned the liver into a state of net carboxylic acid production. The net uptake of lactate plus pyruvate was greatly reduced, mainly due to initiation of a glycolytic flux.
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PMID:Acid-base balance in diabetic ketoacidosis. 680 92

1 A 21-year-old student ingested thirty ricin seeds in a suicidal attempt, some of which were masticated. Three hours later he developed severe diarrhoea with vomiting and abdominal cramps, followed by extracellular dehydration and circulatory collapse. 2 Biological changes included haemoconcentration. He recovered following symptomatic treatment by infusion of saline and glucose solutions. 3 Ricin was quantified by a radioimmunologic method using Iodine 125, and showed that only a small part of the ricin contained in the seeds was absorbed.
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PMID:Acute voluntary intoxication by ricin. 686 67

Phencyclidine HCl was infused intravenously (1.0 mg/kg/min) to unanesthetized mongrel dogs until death. All animals experienced tonic-clonic convulsions (mean convulsive dose: 4.7 +/- 0.3 mg/kg) which lasted until shortly before death (mean lethal dose: 49.8 +/- 2.5 mg/kg). Significant increases in heart rate, arterial blood pressures, cardiac output, body temperature, and arterial pCO2 were observed in all animals. Significant reductions from pre-drug control values were observed in total peripheral resistance, arterial pH, arterial pO2, and respiratory minute volume. Blood lactate, oxygen uptake, and plasma glucose levels rose to values significantly higher than pre-drug control values then declined during the latter phase of the experiment, glucose levels decreased to final values lower than control. Animals appeared to die of primary respiratory failure, which was exacerbated by hyperthermia, and which resulted in final cardiovascular collapse.
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PMID:Acute phencyclidine poisoning in the unanesthetized dog: pathophysiologic profile of acute lethality. 722 56

The respiration of rat liver mitochondria was stimulated by three different ways of energy drain: (a) partial uncoupling (equivalent to direct collapse of the proton-motive force), (b) intramitochondrial utilization of ATP for citrulline synthesis, and (c) extramitochondrial utilization of ATP for glucose phosphorylation. At identical rates of respiration, the intramitochondrial ATP : ADP ratios were the same in all three systems. Furthermore, the proton-motive force was the same in partially uncoupled mitochondria and in the presence of hexokinase plus glucose up to a respiration rate amounting to about 60% of that of the fully active state. However, external ATP : ADP ratios were considerably different in various systems at comparable rates of oxygen uptake, being the lowest under conditions when ATP was being utilized externally. On this basis, it is concluded that the respiratory rate is controlled directly by the proton-motive force and the mitochondrial ATP-synthesizing system operates under near-equilibrium conditions with respect to the membrane energy state parameters. However, a disequilibrium exists at the step of the transport of ATP from mitochondria to the external (cytoplasmic) compartment.
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PMID:Influence of different energy drains on the interrelationship between the rate of respiration, proton-motive force and adenine nucleotide patterns in isolated mitochondria. 728 43

A method is described, based on the differential accumulation of Rb+ and methyltriphenylphosphonium, for the simultaneous estimation of the membrane potentials across the plasma membrane of isolated nerve endings (synaptosomes), and across the inner membrane of mitochondria within the synaptosomal cytoplasm. These determinations, together with measurements of respiratory rates, and ATP and phosphocreatine concentrations, are used to define the bioenergetic behaviour of isolated synaptosomes under a variety of conditions. Under control conditions, in the presence of glucose, the plasma and mitochondrial membrane potentials are respectively 45 and 148mV. Addition of a proton translocator induces a 5-fold increase in respiration, and abolishes the mitochondrial membrane potential. The addition of rotenone to inhibit respiration does not affect the plasma membrane potential, and only lowers the mitochondrial membrane potential to 128mV. Evidence is presented that ATP synthesis by anaerobic glycolysis is sufficient under these conditions to maintain ATP-dependent processes, including the reversal of the mitochondrial ATP synthetase. Addition of oligomycin under non-respiring conditions leads to a complete collapse of the mitochondrial potential. Even under control conditions the plasma membrane (Na+ + K+)-dependent ATPase is responsible for a significant proportion of the synaptosomal ATP turnover. Veratridine greatly increases respiration, and depolarizes the plasma membrane, but only slightly lowers the mitochondrial membrane potential. High K+ and ouabain also lower the plasma membrane potential without decreasing the mitochondrial membrane potential. In non-respiring synaptosomes, anaerobic glycolysis is incapable of maintaining cytosolic ATP during the increased turnover induced by veratridine, and the mitochondrial membrane potential collapses. It is concluded that the internal mitochondria must be considered in any study of synaptosomal transport.
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PMID:Energy transduction in intact synaptosomes. Influence of plasma-membrane depolarization on the respiration and membrane potential of internal mitochondria determined in situ. 737 8

It has long been known that pyruvate is essential for survival of prenatal neurons in culture. To understand the role of exogenous pyruvate in neuronal calcium homeostasis, we have investigated the effects of pyruvate (plus malate) addition to dissociated adult rat hippocampal and cerebral cortex cells and cultured CNS neurons having an unrestricted glucose supply. We found that pyruvate (plus malate) increased the respiration rate while ATP levels were unchanged. At the same time, cytosolic free calcium concentrations, [Ca2+]i, decreased while total 45Ca2+ and 40Ca2+ accumulation increased. The extra Ca2+ accumulated by the cells is attributable to an increase in the size of the intracellular calcium pools. Two such pools were identified on the basis of their sensitivity to specific drugs. The first pool was mobilized by thapsigargin plus tert-butyl hydroquinone and caffeine while the second pool was discharged by the mitochondrial uncoupler carbonyl cyanide p-trifluoromethoxphenylhydrazone (FCCP) (plus oligomycin). The two pools represented about 15-20% and 15-30%, respectively, of the rapidly exchangeable 45Ca2+ pools in cerebral cortex cells. In cultured hippocampal neurons, the collapse of the mitochondrial membrane potential (as induced by uncouplers (FCCP) or respiratory chain inhibitors (antimycin) caused a large increase in [Ca2+]i which varied in size and shape among cells and was reduced by external Ca2+ chelation. The latter condition also resulted in a partial discharge of FCCP-releasable 45Ca2+. The effects of FCCP did not result simply from ATP depletion since incubation in glucose-free medium and sequential additions of 2 mM deoxyglucose and 10 microM oligomycin, conditions that led to a dramatic reduction in cellular ATP levels, did not abolish the FCCP-induced [Ca2+]i rise. Taken together, the results indicate that mitochondria harbor a significant proportion of cellular Ca2+. The sensitivity of the mitochondrial pool size to pyruvate (plus malate) questions previous hypotheses concerning a kinetic limitation for Ca2+ accumulation in mitochondria in resting neurons.
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PMID:The role of pyruvate in neuronal calcium homeostasis. Effects on intracellular calcium pools. 750 25

This study describes some biological properties of human cheek (buccal epithelial) cells, isolated by mouth wash. Yields ranged from 6.5 to 20.6 x 10(6) cells, with a mean (+/- SE) of 12.2 +/- 4.2 x 10(6) cells, which gave 0.55 +/- 0.01 x 10(6) cells/mg protein. Vital stain exclusion was similar in cells isolated in either water (89 +/- 2%) or 250 mM sucrose (87 +/- 3%). From our measurements of cell volume and electrolyte content, we estimated intracellular Na+ and K+ concentrations to be between 0.3-0.5 and 7.4-13.0 mM, respectively. In 22 adult subjects, basal, prickle, intermediate, and superficial cells represented 0.3 +/- 1.4, 51 +/- 2.4, 26 +/- 0.9, and 22.7 +/- 1.8%, respectively, of the total sample. Cheek cells exhibited a low endogenous rate of oxygen consumption, which was stimulated by glucose or succinate and inhibited by KCN or NaF. Cheek cells were osmotically stable in a wide range of media, including water. However, they exhibited shrinkage and collapse in hypertonic media, particularly polyethylene glycol.
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PMID:Osmotic and other properties of isolated human cheek epithelial cells. 751 1

In a retrospective study we analyzed the clinical and blood chemical data of 12 patients with severe tropical malaria in the intensive care units of the University Hospital Zurich and the Stadtspital Triemli, Zurich, between 1991 and 1994. None of the 12 patients had been exposed to malaria before or had taken drugs for chemoprophylaxis. 7 patients survived, 5 died from complications of malaria. According to the criteria of severe tropical malaria defined by the WHO, the following pathological clinical and blood chemical parameters were noted on admission: cerebral coma (2/12); blood hemoglobin < 5 g/dl (0/12), < 8 g/dl (2/12); serum creatinine > 265 mumol/l (3/12); blood glucose < 2.2 mmol/l (0.12); circulatory collapse/shock (0/12); bleeding/signs of disseminated intravascular coagulation in laboratory tests (4/12); acidosis with pH < 7.25 (1/12). Further signs of severe tropical malaria were: hyperparasitemia > 5% (9/12); qualitative and quantitative disturbances of consciousness (6/12); thrombocytopenia < 30 x 10(9)/l (9/12); hyponatremia 125-135 mmol/l (9/12), < 125 mmol/l (2/12); rhabdomyolysis with creatine kinase > 1000 U/l (4/12). The basic treatment consisted of parenteral quinine hydrochloride in all patients; doxycycline was added in 8 cases, clindamycin in 3. Adjuvant therapy with desferrioxamin was given in 3 cases. 6 patients had exchange transfusions. Parasitemia cleared in all patients within 5 to 6 days. Later in the course, 5 patients developed acute respiratory distress syndrome, 6 required hemofiltration due to oliguria, and one became comatose.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Intensive care aspects in severe tropical malaria: clinical aspects, therapy and prognostic factors]. 777 Jul 59

A crude, whole-body extract of female or male heartworms was injected IV into 28 dogs with and 22 dogs without heartworm (HW) infection. The female HW extract caused shock in 22 of 24 dogs with and 12 of 20 dogs without HW infection. The male HW extract induced shock in 4 of 4 dogs with and 1 of 2 dogs without HW infection. Prevalence of shock caused by female HW extract was significantly (P < 0.05) higher in dogs with than without HW infection; shock developed 5 to 30 minutes after HW injection. These signs were observed: marked decrease in blood pressure; collapse (initial collapse); paleness of mucous membranes; weak heart sounds; dyspnea; skin coldness; intestinal hyperperistalsis, and defecation; increases in RBC count, serum total protein concentration, serum osmolality, serum Na and blood glucose concentrations; and decreases in neutrophil, eosinophil, and platelet counts. Alanine transaminase, alkaline phosphatase, and lactate dehydrogenase activities increased substantially from the time of initial collapse to 24 hours after HW injection. Of 39 dogs with shock, 29 recovered from initial collapse, but 5 of the 29 subsequently collapsed again (secondary collapse), with bloody diarrhea followed by death. Of these 39 dogs, 6 died during initial collapse without bloody diarrhea, and 4 were euthanatized during initial collapse. It was confirmed that HW extract had, in fact, induced shock. These clinical, hematologic, and biochemical findings were fundamentally similar to those associated with shock resulting from administration of drugs, such as diethylcarbamazine and milbemycin D, in microfilaremic dogs with HW infection.
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PMID:Clinical, hematologic, and biochemical findings in dogs after induction of shock by injection of heartworm extract. 787 76

A literature review of the clinical syndrome HYPP (Hyperkalemic periodic paralysis) affecting Quarter Horses is given. HYPP is characterized by sporadic attacks of muscle tremors, weakness and/or collapse, lasting for variable periods of time. Diagnosis is based on physical findings in association with hyperkalemia. In horses with HYPP, the regulation of ion transport through the sodium channels in the muscle cells occasionally fails, causing uncontrollable muscle twitching. Further investigations into molecular genetics reveals a mutation in the gene responsible for sodium and potassium regulation. The identification of this gene mutation is the basis for the blood test used to diagnose HYPP. HYPP is inherited as an autosomal dominant trait. Treatment of HYPP attacks by intravenous application of calcium gluconate, bicarbonate and glucose results in rapid recovery. Consequent dietary management and daily administration of acetazolamide effectively controls the disease.
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PMID:[HYPP--hyperkalemic periodic paralysis in horses]. 812 39


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