Antipyrine plasma half-life. In vivo indicator of oxidative metabolic capability in Rhesus monkeys (Macaca mulatta)

Antipyrine plasma half-life (APH) has been used as an indicator of hepatic oxidase activity in rhesus monkeys (Macaca mulatta). Plasma disappearance of 14CH3-N-antipyrine (AP) was measured radiometrically. AP and 3 metabolites were detected using high pressure liquid chromatography. APH was assessed during a 300-day control period and following phenobarbital (PB) pretreatments. Significant interindividual variability was observed requiring that animals be used as their own controls. PB (15 mg/kg i.m., 2/day X 4 days) reduced mean APH values from 81 +/- 12 to 41 +/- 2 min. PB treatment also increased monooxygenase catalyzed aldrin epoxidation, dihydroisodrin hydroxylation and benzo(a)pyrene oxidation measured using liver biopsy homogenates. These parameters permit 'continual' assessment of HMO activity in rhesus monkeys under a variety of experimental conditions.

Nonindependence of feature processing in initial consonants

Mutual dependence in the processing of manner and place of articulation was investigated in two experiments. The first study assessed the location of the voiced-voiceless boundary as a function of place of articulation, and the second investigated the location of the labial-alveolar boundary as a function of manner class. In both experiments, the location of the phonetic boundary systematically varied as a function of the nontarget feature value. These results indicate that the processing of phonetic feature information occurs in parallel, with decisions about one feature influencing the particular value assigned to another feature.

Bone collagen in dysbaric osteonecrosis

Experimental dysbaric osteonecrosis associated with inadequate decompression has been induced in mature female swine. The bone collagen from the radiologically defined lesion in the femur has been analyzed. The total collagen contents were the same for the epiphyseal (F-1), the metaphyseal (F-2), and the diaphyseal (F-3) regions. Soluble bone collagen content obtained by sequential extraction of the samples with acetic acid urea, guanidine, lithium chloride and potassium thiocyanate, decreased by approximately 20% in going from the F-1 to the F-2 to the F-3 regions for both experimental and control samples. The amino acid compositions and acrylamide gel electrophoresis patterns were the same for control and experimental samples. Spectral changes with the MBTH reaction were different for control and experimental collagen samples from all bone regions. The spectral shift and pattern changes which occurred from pH 4 to pH 1 suggested a higher average content of unsaturation in the collagen associated aldehyde groups in the experimental than in the control samples. These findings suggest an enhanced ability to remodel collagen which would be consistent with the histological observation of increased derangement of collagen fibers in the experimental bone samples.

Management of perforating diverticulitis of the colon

A retrospective study was carried out of all patients admitted to the hospital with either local or free perforating diverticulitis. Fifty-one patients had perforating diverticulitis of the sigmoid colon with local abscess formation, while 26 patients had free perforation with generalized peritonitis. Of the 67 patients who had a defunctioning colostomy, 18 died, while of ten patients who had either resection or exteriorization of the perforated segment, one died. Thus, exteriorization or resection as the primary surgical procedure for perforating diverticulitis is the procedure of choice, since it leads to a low operative mortality because of removal of the septic focus, preventing continuing intraperitoneal soilage.

Lack of association of human "B cell" antigens and Fc receptor activity of antibody-dependent cytotoxic lymphocytes

Heterologous antisera directed against human B cell antigens were tested for their ability to inhibit the function of Fc receptors on human lymphocytes. These antisera coated on the attacking cells in a lymphocyte-dependent antibody-mediated cytotoxic assay inhibited lysis of sensitized target cells. However, the F(ab)2 fragments of the IgG fraction of an anti-human Ia antiserum failed to inhibit the killing of sensitized targets by attacking cells. Antisera against other lymphocyte membrane antigens also inhibited target cell lysis when coated on attacking cells. These results suggest that there is not identity between human B cell antigens and Fc receptors of antibody-dependent cytotoxic lymphocytes.

Charcot arthropathy secondary to amyloid neuropathy

Neuropathic (Charcot) ankle joints developed in a 50-year-old patient with end-stage renal disease from primary, nonfamilial amyloidosis. Sensory neuropathy in the legs had been noted three years before the onset of uremia and had porgressed. Sural nerve, but not synovial biopsy specimen, showed amyloid in and around arteriolar walls by light and electron microscopy. Since Charcot joints are only rarely associated with amyloid neuropathy, it is possible that uremic neuritis, or prolonged survival by dialysis, contributed to progression of the neuropathy, allowing subsequent joint degeneration.

Monooxygenase-catalyzed aldrin epoxidation and dihydroisodrin hydroxylation in monkey liver needle-biopsy specimens. Assay and properties

Aldrin epoxidation and dihydroisodrin (1,8,9,10,11,11-hexachloro-2,3-7,6-endo-2,1-7,8-endo-tetracyclo [6.2.1.1(3), (6).0(2), (7)]dodec-9-ene (DHI) hydroxylation have been studied in 0.2-ml liver monooxygenase preparations. Liver biopsy specimens of rhesus (Macaca mulatta) and bonnet (M. radiata) monkeys obtained with a 1.9-mm Menghini needle were the primary enzyme sources. Dieldrin and monohydroxydihydroisodrin (DHI-OH) were the only metabolites detected by electron-capture GLC analysis of hexane extracts of incubation media. Incubation, extraction, and analysis could be done in the same vessel. Maximum rates were obtained in the presence of NADPH and O2, and both transformations were inhibited by CO. The apparent KM and Vmax (+/-SD) for epoxidation was 1.2 +/- 0.2 X 10(-5) M aldrin and 210 +/- 20 pmol of dieldrin per mg of protein per min, and the corresponding values for hydroxylation were 2.3 +/- 0.4 X 10(-5) M DHI and 150 +/- 20 pmol of DHI-OH per mg of protein per min. Aldrin epoxidation and DHI hydroxylation activities of rhesus monkey liver biopsy and rat liver preparations were evaluated after phenobarbital treatment. The assay procedures can be used in protocols in which animals serve as their own controls.

Aflatoxin B1 hydroxylation: sensitive monooxygenase microassay suitable for liver biopsy specimens

A method for measuring the rate of monooxygenase catalyzed hydroxylation of aflatoxin B1 to aflatoxin Q1 has been developed. It is suitable for use with small amounts of tissue obtained by needle or surgical biopsy of liver. Liver samples are homogenized in buffered saline containing a glucose-6-phosphate:NADPH generating system. 14C-AFB, is added to initiate the 10 min oxidation period. Quick-freezing stops oxidations, and AFB1 and AFQ1 are extracted using CHCl3. After solvent removal, the residue is resuspended in benzene-acetonitrile (98:2) and applied to silica gel thin-layer chromatography plates which are developed twice in chloroform-acetone-n-hexane (85:15:20). AFB1 and AFQ1 were located by fluorescence and scraped into vials for scintillation counting. The reaction was linear for 10 min using 5-10 mg liver tissue per 0.2 ml incubation. Aflatoxin M1 and 3 other metabolites more polar than AFB1 were also produced. The apparant Km for AFQ1 formation was 8.6x10(-4)M and Vmax was 287 picomoles AFQ1 mg protein-1 min-1 using bonnet monkey Macaca radiatea liver. The procedures should be valuable in comparative biochemical studies, especially those using liver biopsy specimens of primates.

Separation of complement-dependent and lymphocyte-dependent cytotoxic activity in human sera

Two human sera having both complement-dependent and lymphocyte-dependent antibody activities (CDA, LDA) were applied to isoelectrofocusing columns. Maximum LDA activity for both sera was found focused at a higher pH than maximum CDA activity. The studies suggest that LDA molecules may exist without having complement-dependent activity.

Plasmin inhibition of thrombin-induced platelet aggregation

The effects of plasmin treatment upon washed human platelets were studied in an attempt to elucidate the mechanisms underlying thrombin-induced platelet aggregation. At calcium concentrations of 10-20 muM, PLASMIN (0.2 CTA U/ml) inhibited thrombin-induced aggregation almost completely, but did not diminish the thrombin-induced release of adenine nucleotides, 5-hydroxytryptamine, or calcium. Increasing the calcium concentration partially antagonized plasmin's inhibition of aggregation. Studies utilizing calcium chelators and the Kunitz soybean trypsin inhibitor (SBTI) as a plasmin inhibitor indicated that in order to achieve maximal block of aggregation, plasmin must act upon a substrate made fully available only after an initial thrombin-platelet interaction has taken place. Moreover, the time course of this inhibition parallels the time course of the thrombin-induced release reaction. Plasmin inhibition of aggregation could not be mimicked by exposing the platelets to proteolytic digests of fibrinogen at concentrations as high as 17% total platelet protein. Nor could inhibitory activity be recovered from supernatants of plasmin-treated platelets, upon centrifugation and treatment with SBTI. With the use of a "cold initiation" technique, the release by thrombin of 46.7 plus or minus 6.7 (mean plus or minus SEM) mu-g of fibrinogen immunological equivalents per mg platelet protein could be demonstrated. Platelets in which thrombin-induced aggregation was abolished by plasmin treatment (and the plasmin subsequently inactivated by STBI) aggregated normally upon addition of as little as 10 mu-g human plasma fibrinogen per mg platelet protein. It is concluded that plasmin inhibition of aggregation most likely results from its attack upon a protein that is released or becomes fully available subsequent to interaction of thrombin with a platelet receptor mediating release. The results of this study are consistent with a cofactor role for fibrinogen in the aggregation of human platelets by thrombin.

Hepatic and metabolic effects of ethanol on rhesus monkeys

Rhesus monkeys were tube-fed 100 calories per kg of a liquid diet based on casein in which 41% of the calories were derived from grain alcohol. The alcohol intake was 5.8 g per kg per day. Control diets contained isocaloric amounts of glucose. The protein content of the diet was 15% and fat supplied 21% of the calories. After 28 days the animals which had been fed ethanol developed hepatic fatty change and serum L.D.H. levels were elevated. The most striking electron microscopic changes in the alcohol animals were mitochondrial swelling, focal cytoplasmic degradation, and dilatation of the rough endoplasmic reticulum. In the monkeys which had received ethanol the metabolism of alcohol increased from 17.4 mg per 100 ml per hour to 26.6 mg and antipyrene half-life decreased from 61.0 minutes to 49.9 minutes. The carbohydrate animals showed no significant change in alcohol metabolism or antipyrene half life. The ethanol animals lost weight significantly while the carbohydrate animals gained significantly. The metabolic effects of alcohol thus were not reproduced by glucose. Administration of phenobarbital at 30 mg per kg for 5 days increased alcohol metabolism from 16.5 mg per hour to 22.5 mg per hour and shortened antipyrene half life from 76.5 minutes to 33.6 minutes. Alcohol and phenobarbital both induced enhanced drug metabolism but alcohol was a more powerful inducer of its own metabolism than phenobarbital. Phenobarbital on the other hand was a better inducer of antipyrene metabolism than alcohol.