Renal and splanchnic circulation during infrarenal aortic cross-clamping

The effect of infrarenal cross-clamping of the aorta on regional splanchnic and renal circulations was studied in seven dogs. Regional blood flow was determined with differentially labeled microspheres (9 and 15 micron in diameter) that were injected simultaneously into the left atrium. Blood flow was measured 30 minutes after surgical preparation was completed (stage I), 20 minutes after infrarenal aortic cross-clamping (stage II), and 20 minutes after supplemented sodium nitroprusside infusion (stage III). Infrarenal aortic cross-clamping was accompanied by a slight increase in the cardiac output (CO) without significant changes in mean arterial pressure (MAP). Blood flow through the gut, hepatic artery, and cortical layer of the kidneys, as determined with 15-micron spheres, was not changed. Nonentrapment of 9-micron spheres in the gut and renal cortex was increased substantially. Blood flow through the juxtamedullary layer of the kidneys was increased. Sodium nitroprusside supplementation decreased MAP by 30%; CO values returned to baseline level. Hepatic artery blood flow, compared with both baseline values and values during aortic cross-clamping, increased significantly. Blood flow, determined with 15-micron spheres, through the gut and renal cortex did not change, and nonentrapment of 9-micron spheres decreased to baseline values. The data suggest a certain shift of blood flow to the juxtamedullary layer of the kidneys during aortic cross-clamping and normalization of intrarenal blood flow distribution during supplemented sodium nitroprusside infusion. Controlled vasoplegia with sodium nitroprusside may help modify peripheral circulatory disturbances in the kidneys and splanchnic system during infrarenal aortic cross-clamping.

Common action of certain viruses, toxins, and activated complement: pore formation and its prevention by extracellular Ca2+

Haemolysis by Sendai virus, alpha-toxin, and activated complement is inhibited by high concentrations of divalent cations. In Daudi cells, sublytic amounts of these agents induce the following changes: collapse of surface membrane potential, uptake of Na+ and loss of K+ from cells, and leakage of phosphorylated metabolites from cells. The changes induced by Sendai virus and complement are sensitive to physiological concentrations of extracellular Ca2+. It is concluded that fluctuations in plasma Ca2+ concentration may affect the damaging action of certain pore-forming agents on susceptible cells.

Reduced glutathione protection against rat liver microsomal injury by carbon tetrachloride. Dependence on O2

Rat liver microsomal membranes contain a reduced-glutathione-dependent protein(s) that inhibits lipid peroxidation in the ascorbate/iron microsomal lipid peroxidation system. It appears to exert its protective effect by scavenging free radicals. The present work was carried out to assess the effect of this reduced-glutathione-dependent mechanism on carbon tetrachloride-induced microsomal injury and on carbon tetrachloride metabolism because they are known to involve free radicals. Rat liver microsomes were incubated at 37 degrees C with NADPH, EDTA and carbon tetrachloride. The addition of 1 mM-reduced glutathione (GSH) markedly inhibited lipid peroxidation and glucose 6-phosphatase inactivation and, to a lesser extent, inhibited cytochrome P-450 destruction. GSH also inhibited covalent binding of [14C]carbon tetrachloride-derived 14C to microsomal protein. These results indicate that a GSH-dependent mechanism functions to protect the microsomal membrane against free-radical injury in the carbon tetrachloride system as well as in the iron-based systems. Under anaerobic conditions, GSH had no effect on chloroform formation, carbon tetrachloride-induced destruction of cytochrome P-450 or covalent binding of [14C]carbon tetrachloride-derived 14C to microsomal protein. Thus, the GSH protective mechanism appears to be O2-dependent. This suggests that it may be specific for O2-based free radicals. This O2-dependent GSH protective mechanism may partly underlie the observed protection of hyperbaric O2 against carbon tetrachloride-induced lipid peroxidation and hepatotoxicity.

Ca2+-sensitive permeability changes caused by influenza virus

Influenza virus added to Lettré cells at pH 5.3 induces a permeability change similar to that elicited by Sendai virus at pH 7.4: K+ and Na+ equilibrate across the plasma membrane and low-molecular-weight phosphorylated compounds leak out of cells, which remain impermeable to trypan blue.

Thromboxane B2 (TxB2) metabolism in rat isolated lung and its inhibition by drugs

In rat isolated lung perfused via the pulmonary circulation, 3H-TxB2 was metabolized to another radioactive species. About 60% of effluent 3H was metabolite and the same proportion of metabolite was found in lung at 5 min after the injection of 3H-TxB2. Metabolism of TxB2 was prevented by bromcresol green, dipyridamole and frusemide apparently by decreasing uptake of TxB2 by the lung. Our results support the possibility of TxB2 competing with PGE2 for metabolism in lung, although TxB2 is not a substrate for PGDH in vitro.

Neuroblastoma, tuberous sclerosis, and subependymal giant cell astrocytoma

A patient with Stage III paratesticular neuroblastoma diagnosed in infancy was treated with radiotherapy and chemotherapy. Typical depigmented "ash leaf" skin lesions of tuberous sclerosis appeared during early childhood. At 7 years of age he underwent craniotomy for a subependymal giant cell astrocytoma. The occurrence of neuroblastoma, tuberous sclerosis, and astrocytoma is unique, and supports the suggested relationship between neural crest tumors and hamartoma syndromes.

Kaposi's sarcoma and T-cell lymphoma in an immunodeficient woman: a case report

The acquired immunodeficiency syndrome has now been reported among more diverse groups of patients, and as each new category of patients is described, additional epidemiological and pathological insights are gained. Adult non-Haitian women with AIDS have so far generally been reported to have had male partners who have AIDS, are intravenous drug users or both. The present case is being reported because she was a non-Haitian, who did not use drugs and denied sexual contact with men. Pathologic and clinical findings in this case are consistent with AIDS and include: early generalized lymphadenopathy, pronounced lymphocytopenia, fever, hepatosplenomegaly, Kaposi's disease present, in lymph nodes, disseminated candidiasis, anergy to skin testing for delayed hypersensitivity reactions.

Intergovernmental relations in physician education and health planning: state adoption decisions and the impact of federal programs

This study seeks to explain states' adoptions of programs in health planning and in physician education. It also seeks to further understanding of the impact of federal health planning and education programs on the states. Several theories and models are employed in analyzing the actions of state decision-makers. These include incremental theory, models of the diffusion of innovations, economic resources theory, and a theory of competitive partisanship. The data utilized in this research were principally derived from intensive interviews with "key" state actors and from historical, documentary materials. Only minimal federal impact appears on states' goals in physician education and health planning. Rather, there is evidence of considerable innovativeness among the states prior to Federal program initiatives. A problem-generated search for solutions seems to be a major source of this innovation. Finally, federal program implementation requirements appear to be a major source of federal--state conflict and opposition.

Carbon monoxide diffusing capacity in polycythaemia rubra vera

The diffusing capacity of the lung, or transfer factor, for carbon monoxide (TLCO) was measured in 12 patients with polycythaemia rubra vera. This was significantly raised (mean 152% predicted, SEM +/- 14%) and remained so even after correction to a standard haemoglobin concentration of 14 . 6 g/dl (mean 139% predicted, SEM +/- 13%). Serial measurements of TLCO on two patients after treatment of polycythaemia rubra vera showed a greater fall in relation to haemoglobin concentration than would have been predicted on theoretical grounds if the increases in TLCO had been due entirely to the increased haemoglobin concentration. The pulmonary capillary blood volume (estimated from TLCO) also fell in these two patients after treatment. There was a strong correlation between TLCO and the technetium-99m-labelled red cell volume for the seven men (r = 0 . 92; p less than 0 . 01) and five women (r = 0 . 99; p less than 0 . 001) when studies were performed on the same day. In patients with polycythaemia rubra vera who have no evidence of coexistent pulmonary disease the pulmonary capillary bed appears to share in the expansion of the body blood volume. The single-breath TLCO test may act as a convenient and simple monitor for the response of the disease to treatment.

Human cytomegalovirus DNA: BamHI, EcoRI and PstI restriction endonuclease cleavage maps

The cloned HindIII fragments of human cytomegalovirus (HCMV) strain AD169 DNA were mapped with respect to the BamHI, EcoRI and PstI restriction endonuclease cleavage sites. Composite restriction endonuclease cleavage maps for the entire virus genome were constructed using the previously established linkages between the HindIII fragments.

Succinylcholine-induced hyperkalemia in the rat following radiation injury to muscle

During anesthetic preparation of a patient who had received routine radiation therapy for sarcoma of the leg, cardiac collapse occurred following succinylcholine (SCh) administration. Experiments were designed to test the hypothesis that radiation injury to muscle might cause increased sensitivity to SCh similar to that reported in patients with muscle trauma, severe burns, and lesions causing muscle denervation. Venous plasma potassium levels and arterial blood gas tensions were measured in rats after they were given SCh (3 mg/kg) at various times following 60Co irradiation of the hind legs. Nonirradiated rats responded to SCh with a slight but statistically significant increase in plasma K+. Rats subjected to high levels of radiation (10,000 to 20,000 R) and given SCh 4 to 7 days later responded in the same way as the control rats. Plasma K+ levels in rats exposed to a fractionated irradiated dosage (2500 R given twice with a 1-week interval) followed by SCh 1 week later were similar to those in the control group, but when SCh was given 2 weeks later (3 weeks after initial irradiation) there was a marked elevation of plasma K+, from 3.6 to 7.7 meq/L, a statistically significant increase.

Acrylonitrile: in vivo metabolism in rats and mice

Acrylonitrile (VCN) is metabolized to cyanide in rats and mice. Cyanide levels following oral administration of an LD50 of VCN or KCN were determined in blood and organs of treated rats and mice. After administration of VCN, cyanide levels were significantly lower than those following treatment with KCN in rats, whereas in mice the difference was not significant. Differences in VCN toxicity signs were observed in rats and mice. In rats, early VCN toxicity signs were cholinomimetic such as: salivation, diarrhea, peripheral vasodilatation, and excessive gastric secretion. These signs differed from the central nervous system disturbances (depression, convulsions and respiratory failure) observed following KCN. In mice, however, the only signs of VCN toxicity were central nervous system effects, identical to those following KCN. Blood cyanide concentrations after VCN were dose-dependent in both species. Maximum blood cyanide concentrations were observed 1 hr after dosing in mice but at 3 hr in rats. Treatments with phenobarbital or Aroclor 1254, or fasting, increased blood cyanide concentrations after VCN. Treatments with cobaltous chloride or SKF 525-A resulted in decreased blood cyanide concentrations after VCN. These data indicate that there are species differences in VCN toxicity and metabolism and suggest that VCN is metabolized to cyanide via a mixed-function oxidase enzyme system.

Acidic phospholipases in cultured human fibroblasts: deficiency of phospholipase C in Niemann-Pick disease

Radioactive phosphatidyl choline substrates specifically labeled in the one position or two position fatty acid were used to establish conditions for the detection of acidic phospholipase A1, A2 and C activities in extracts of cultured human fibroblasts. Maximal activity was detected at a pH of 3.0, 4.0 and 5.0 respectively, suggesting that the enzymes are of lysosomal origin. None of the activities were stimulated or inhibited markedly by Ca2+ or EDTA. The A1 and A2 activities, but not the C activity, were inactivated by the sulfhydryl reactive Ellman reagent. All three enzyme activities were in the normal range for cultured fibroblasts which were deficient in acid lipase, indicating that these activities are not attributable to the acid lipase gene product. Phospholipase A activity was deficient in fibroblast extracts from patients with Niemann-Pick disease, types A, B and C. These data suggest either identity or a genetic relationship between sphingomyelinase and phospholipase C. The activities examined were within the normal range in fibroblasts from patients with neuronal ceroid lipofuscinosis, sea blue histiocyte disease and selected uncharacterized degenerative diseases.

Juvenile rheumatoid arthritis. A comparison of patients from the USSR and USA

Juvenile rheumatoid arthritis (JRA) in the Union of Soviet Socialist Republics (USSR) and the United States (USA) shows a remarkable similarity in age of disease onset, subtype onset, frequency, and most laboratory measurements. There is variation in the therapeutic approach with heavier reliance on aspirin in the USA. The evolution of JRA from onset subtype to final subtype over 5 years was the same in both groups and was independent of the type of therapy.

Variability in gas production by Escherichia coli in enrichment media and its relationship to pH

Variability in gas production in multiple subcultures of Escherichia coli was assessed in two selective enrichment media and in lactose peptone water. Considerable variability occurred with all media at 37 and 44 degrees C. Addition of buffer increased gas production and decreased variability. The relationships between pH, growth, and gas production were complex. In buffered media, viable counts increased by 269 x 10(6) to 382 x 10(6)/U of pH fall, whereas in unbuffered media, they increased by 9.45 x 10(6) to 30.37 x 10(6)/U of pH fall. In buffered and unbuffered media, pH fell as gas production rose. However, variability in gas production among individual subcultures was not associated with changes in pH.

Interpretation of increases in the transfer coefficient for carbon monoxide (TLCO/VA or KCO)

During a 15-month period, 27 patients were seen in a routine clinical pulmonary function laboratory in whom the transfer coefficient (TLCO/VA or KCO), measured by the single breath technique, was increased. Pulmonary haemorrhage accounted for two-thirds of the cases; in them sequential measurements of KCO were able to monitor the onset and cessation of bleeding. In the remaining cases the cause of the increase in KCO remains uncertain. All patients had a reduction in vital capacity. Experiments in six normal subjects showed that KCO rose as the breath-holding lung volume was reduced, but that this was insufficient to account for the raised KCO in patients with reduced volumes. Partitioning of the two components of TLCO at different lung volumes in three normal subjects showed that an increase in pulmonary capillary blood volume per unit alveolar volume was chiefly responsible for the increase of KCO in normal subjects at lower lung volumes. The membrane diffusing capacity changed less than predicted per unit volume, suggesting that the thickness of the air-blood barrier remains fairly constant as the lung expands or contracts.

The Rees system in infants: fresh gas flow and PaCO2

Fresh gas flow from the anaesthetic machine can be set to determine the low level of PaCO2 that is achieved during anaesthesia using Rees variation of the T-piece. It does not however set the upper limits for PaCO2 which is more reliant upon the minute ventilation. For a PaCO2 of 40 mm Hg, it is suggested that the fresh gas flow from the machine be 220 cc/kg. For small infants, a higher flow rate is necessary.

Airway hyperreactivity and peripheral airway dysfunction in influenza A infection

We studied 39 consecutive college students with documented nonpneumonitic influenza A/Victoria/3/75/H3N2 infection to examine alterations in pulmonary mechanics and airway reactivity to cholinergic challenge, and to assess the effect of the antiviral agent amantadine on these changes. Thirty-six of the 39 subjects (92 per cent) demonstrated diminished forced flow rates and decreased density-dependent forced flow rates while breathing a helium-O2 mixture as compared to an air mixture. On initial evaluation, there was no significant difference in forced flow rates or density dependence between a group of 18 subjects treated with amantadine and 21 subjects given a placebo. However, the placebo group demonstrated further decreases in density dependence 7 days after initial presentation, whereas the amantadine group demonstrated a significant increase in density dependence (P less than 0.05), which suggested an accelerated improvement in peripheral airway dysfunction in the treated group. After inhalation of carbachol aerosol, 25 subjects showed a significant (P less than 0.05) increase in total respiratory resistance that was prolonged and independent of hay fever history. Airway hyperreactivity gradually diminished during a 7-week period in both groups. There was no significant difference in the initial degree of hyperreactivity or in the rate of improvement between groups. These data suggest that nonpneumonitic influenza infection may be associated with both an inflammatory response predominantly in the peripheral airways and transient bronchial hyperreactivity. By means of its antiviral effect, amantadine may arrest the proliferation of virus and associated inflammatory response in peripheral airways, but airway hyperreactivity presumably related to initially damaged airway depithelium is not attenuated by inhibition of viral replication after infection has been established.

Prevention of nitroprusside-induced cyanide toxicity with hydroxocobalamin

To investigate hydroxocobalamin's role in preventing cyanide intoxication from sodium nitroprusside, we studied two groups of patients. One group received nitroprusside alone, and the other received nitroprusside and hydroxocobalamin. Red-cell and plasma cyanide levels were 83.44 +/- 23.12 and 3.51 +/- 1.01 microgram per 100 ml after nitroprusside alone and were 33.18 +/- 17.29 and 2.18 +/- 0.65 microgram per 100 ml after nitroprusside plus hydroxocobalamin. Acidosis developed in patients with red-cell cyanide levels higher than 75 microgram per 100 ml. When hydroxocobalamin infusion was stopped before sodium nitroprusside infusion was discontinued, blood cyanide levels and base deficit increased in a manner similar to that in the untreated group. The dose of nitroprusside used in each group did not differ statistically. These data show that hydroxocobalamin prevents cyanide transfer from red cells and plasma to tissue after nitroprusside metabolism, and thereby prevents cyanide toxicity from large intravenous doses of the drug.

Intracranial pressure changes induced by sodium nitroprusside in patients with intracranial mass lesions

Because of the ability of sodium nitroprusside (SNP) to dilate cerebral blood vessels, intracranial pressure (ICP) should increase with its use. In patients with vascular intracranial tumors following SNP (0.01%) infusion, ICP increased from 14.58 +/- 1.85 to 27.61 +/- 3.33 torr (p greater than 0.0005) and cerebral perfusion pressure decreased from 89.32 +/- 3.5 to 43.23 +/- 4.60 torr (p less than 0.0005) when the mean arterial pressure had reduced by 33%. These results suggest that SNP not be used in patients with raised ICP unless previous measures have been taken to improve intracranial compliance.

Relation of PaCO2 to fresh gas flow in a circle system

Recent reports have described methods of controlling the level of CO2 during anesthesia with a N2O-relaxant sequence and controlled ventilation. This paper describes a method of predicting and controlling the PaCO2, using body weight for determination of the fresh gas flow from the anesthetic machine, removing the absorbent from the canister while leaving the canister in the circuit, and controlling ventilation at 12 ml/kg and at 12/min.

Tubocurarine and the neonate

Tubocurarine, given as a single bolus, may be used safely for neuromuscular blockade in the neonate. The recommended dose is 250 mug/kg at birth, increasing to 500 mug/kg at 28 days of age. This dose should be reduced in the event of prematurity, acidosis or hypothermia, or when certain antibiotics or inhalation anaesthetic agents are present in the tissues. A single dose as described has a duration of approximately 1 h and it is only after this time that satisfactory antagonism can be obtained. The potency of pancuronium when compared with tubocurarine in the study is 6:1, from birth to 28 days.

Induced changes in the electron paramagnetic resonance spectra of mammalian catalases

The EPR spectra of bovine liver catalase, rat liver catalase and human erythrocyte catalase have been measured at 9.0 degrees K. In N-2-hydroxyethylpiperazine-N'-2-ethanesulphonic acid (HEPES) and Tris buffers at pH 7.0, the liver catalases show EPR spectra typical of rhombically distorted high spin ferric heme with major lines at g = 6.50, 5.35, 1.98. A number of extra lines are also seen; these are weak or absent in human erythrocyte catalase. The effect of the addition of formate, nitrite, acetate, fluoride, azide, hypophosphite and of inactivation with 3-amino-1,2,4-triazole on the degree of rhombic distortion has been studied. There is a good correlation between the low temperature EPR and room temperature optical changes for the binding of formic acid in HEPES and Tris. There is no evidence from EPR spectra for the presence of heme-heme interactions in the binding of formic acid to human erythrocyte catalase. The properties of catalase are altered in phosphate and in distilled water. This is a consequence of the low temperature of measurement.