Structural requirements of alkyl acyldithiocarbazates for the uncoupling of oxidative phosphorylation in mitochondria

A structure-activity relationship study on the uncoupling of alkyl acyldithiocarbazates was carried out. Greater activity was observed with increasing alkyl chain length, the optimum being C9. A further increase in alkyl chain length caused a decrease in the activity. Thione-thiol tautomeric forms with a dissociable proton were dound to be of primary importance for the uncoupling and the role of the acyl group was auxiliary. The reactivity of the SH group of alkyl acyldithiocarbazates with an SH-reagent was very low. These compounds facilitated the valinomycin-induced swelling of non-respiring mitochondria and non-sonicated lecithin liposomes in isotonic potassium acetate solution.

Syntheses and uncoupling activities of alkyl dithiocarbazates and alkyl pyridinecarbonyldithiocarbazates

A series of alkyl dithiocarbazates, alkyl 3-picolinoyldithiocarbazates, alkyl 3-nicotinoyldithiocarbazates, alkyl 3-isonicotinoyldithiocarbazates, and alkyl 3-picolinoyl-2-methyldithiocarbazates was prepared. These alkyl pyridinecarbonyldithiocarbazates were shown to be uncouplers of oxidative phosphorylation in mitochondria. The finding that uncoupling activity increased with increase in the length of the alkyl chains of the compounds indicates that hydrophobicity influences the activity. The nonyl derivatives had the highest activity. The results also suggested that a dissociable acidic proton is necessary for the uncoupling activity.

[Effect of cardiocrome on EEG arousal response (author's transl)]

The experiment was made on effect of Cardiocrome (containing Cytochrome c, Co-Carboxylase and Flavin mononucleotide), Cytochrome c and Cytidine diphosphate (CDP) choline on the EEG arousal response induced by electrical stimulation of mesencephalic reticular formation in 68 unanesthetized immobilized cats. The arousal response was accelerated by intravenous injection of Cardiocrome, Cytochrome c and CDP-choline. The accelerating effect of Cardiocrome was more prominet than that of Cytochrome c. In conclusion, it can be drawn that Cardiocrome has an arousal effect on consciousness.

[Combined treatment of intravenous immunoglobulin and antibiotics for severe postoperative meningitis (author's transl)]

Incidence of postoperative meningitis by gram-negative bacilli infection, so called "opportunistic infections", has recently increased in the neurosurgical field. The opportunistic infection is caused by suppression of the host's immunity and consequently limitation of the host defense mechanisms. Based on the results obtained from 4 cases of postoperative severe meningitis presented here, the authors concluded as follows: 1) Special care must be taken for intrathecal injection of antibiotics because of causing paralytic ileus, convulsion and paraparesis of the lower limbs. 2) The combined use of intravenous immunoglobulin (Gamma-Venin) and antibiotics produced potentiated effects. Accordingly, the amplification of the host's immunity is of major importance for the treatment of severe meningitis. 3) Using immunoadherence hemagglutination test of patient's CSF and the serum, it is considerably easier to determine whether or not to withdraw antibiotics.

Oligopeptides as potential antiaggregation agents for deoxyhemoglobin S

Oligopeptides that mimic segments of the amino acid sequence of hemoglobin S at potential contact sites can be used to inhibit aggregation. These oligopeptide inhibitors raise the minimum gelling concentration of deoxyhemoglobin S so that chemical modification does not have to be used. The hexapeptide amides of both betaS 1-6 which is believed to be one of the contact areas among aggregates, and betaA 1-6 of hemoglobin A increase the minimum gelling concentration by more than 70%. The hexapeptide amide beta79-84 behaves like beta1-6 (beta being betaS or betaA). Shorter oligopeptides, such as betaS3-6, are less effective as an inhibitor but longer ones, such as betaS1-8, are no more effective than beta1-6. Permutations of the sequence, such as betaS125634, do not alter the percent increase in the minimum gelling concentration. Leu- and Met-enkephalin increase the minimum gelling concentration just as beta1-6 does, but (Pro)6 is not very effective. Thus, the use of complementary oligopeptides as inhibitors is extended to include certain "flexible" peptides, which can adapt themselves to interfere with the molecular contacts and thereby gelation of deoxyhemoglobin S.

[A study of excitability changes in DSCT neurons of the cat (author's transl)]

Excitability changes in the dorsal spinocerebellar tract (DSCT) neurons of the cat were extracellularly studied with correlation analysis. Most of the interval histograms were classifed as normal distribution, and occasionally bimodal distributions were observed, which resulted from an occasional "double spiking" in the spontaneous background discharge (BD). The conduction velocity was measured in 72 DSCT fibers. The histogram showed a peak at 40-50 M/S. The majority of the units had BD with coefficient of variation less than 0.2, which suggest BD with regular firing. Based on cross-correlelograms, DSCT responses to electrical stimulation of the muscle nerves of the hind leg were classified into at least three types. Type 1 response, constituted approximately one-fifth of the total, is monosynaptic activation. Type 2 response, observed most frequently (47%), is inhibition of DSCT cells with a short latency. Type 3 responses, observed nearly as often as type 2 (34%), is a long latency excitation, undoubtedly polysynaptic. Changes in stimulation intensity showed complex changes in the pattern of response. Type 1 and 2 responses were unaffected by increasing stimulus rate. Peak correlations in type 3 response were reduced by increase in stimulus rate. There were no data demonstrating feedback circuitry associated with collaterals of DSCT axons. This suggest that axon collaterals have no direct effect on the activity of Dsct cells.

A determination of excitability changes in dorsal spinocerebellar tract neurons from spike-train analysis

1. Responses of DSCT neurons to random electrical stimulation of peripheral nerves of the hindleg at group I intensity were studied using cross-correlation analysis of the output spike train with the stimulus. Three types of response were found: type 1 was due to monosynaptic activation of DSCT cells, type 2 resulted from inhibition of those cells, and type 3 was due to a long-latency excitation that was probably polysynaptic. 2. Most of the units studied responded to stimulation of both proximal and distal flexor and extensor nerves. The extensive convergence of afferent input on DSCT cells is much greater than has been observed previously, with type 2 and type 3 responses totaling 80% of the observed responses. We attribute this to the sensitivity of the analysis in detecting small changes in postsynaptic excitability. 3. The results of the study, particularly the derivation of postsynaptic excitability changes, generally confirm those of earlier work employing intracellular recording. 4. By varying stimulus rate and stimulus intensity in the group 1 range and simulating the resulting correlations, we conclude that excitability changes in DSCT cells are the net result of complex interactions involving excitation and inhibition. A summary of these findings is presented as a model for the minimum circuitry necessary to account for the observed behavior.

Studies on the microsomal electron-transport system of anaerobically grown yeast. V. Purification and characterization of NADPH-cytochrome c reductase

A flavoprotein catalyzing the reduction of cytochrome c by NADPH was solubilized and purified from microsomes of yeast grown anaerobically. The cytochrome c reductase had an apparent molecular weight of 70,000 daltons and contained one mole each of FAD and FMN per mole of enzyme. The reductase could reduce some redox dyes as well as cytochrome c, but could not catalyze the reduction of cytochrome b5. The reductase preparation also catalyzed the oxidation of NADPH with molecular oxygen in the presence of a catalytic amount of 2-methyl-1,4-naphthoquinone (menadione). The Michaelis constants of the reductase for NADPH and cytochrome c were determined to be 32.4 and 3.4 micron M, respectively, and the optimal pH for cytochrome c reduction was 7.8 to 8.0. It was concluded that yeast NADPH-cytochrome c reductase is in many respects similar to the liver microsomal reductase which acts as an NADPH-cytochrome P-450 reductase [EC 1.6.2.4].

Studies on the microsomal electron-transport system of anaerobically grown yeast. IV. Purification and characterization of NADH-cytochrome b5 reductase

The presence of NADH-cytochrome b5 reductase [EC 1.6.2.2] in microsomes from anaerobically grown yeast was confirmed by its isolation and purification. The purified preparation of the reductase showed an apparent molecular weight of 27,000 daltons. The reductase appeared to contain loosely-bound FAD as a prosthetic group. The reductase required NADH as a specific electron donor, and could reduce some redox dyes as well as cytochrom b5. The reductase, however, could not reduce cytochrome c. Michaelis constants of the reductase for NADH and calf liver cytochrome b5 were 6.3 and 1.5 micron M, respectively, and optimal pH for cytochrome b5 reduction was 5.6. Although some differences exist between the properties of NADH-cytochrome b5 reductase from yeast and from mammalia, the results indicate a functional similarity of the present enzyme to mammalian NADH-cytochrome b5 reductase in the microsomal electron-transport system.

[A case of suprasellar tumor associated with so-called atypical angina pectoris]

A case of suprasellar tumor associated with so-called atypical angina pectoris was reported. A 58-year-old man was admitted to our hospital on Feb. 2, 1973, because of headache, disturbance of visual field and the attack of chest pain. He had been suffering from disturbance of visual field for about 3 years and the attack of chest pain for about 4 months prior to admission. Neurological findings on admission were bitemporal hemianopia, decreased visual acuity and atrophy of the optic disc. Bilateral carotid angiography showed upward displacement of A1 portion of the anterior cerebral artery. Pneumoencephalography demonstrated defect of the anterior part of the third ventricle. Laboratory examination showed hypopituitalism. On March 26, 1973, Right frontal craniotomy was performed under the diagnosis of suprasellar tumor. The walnut-sized tumor was detected in the suprasellar region and removed totally. Histological examination showed dermoid cyst. With regard to the attack of chest pain, the selective coronary angiography was performed. But organic change was not detected and Master's two step test did not induce any pathological finding in EEG. So we made a diagnosis of so-called atypical angina pectoris. There are many arguments about pathogenesis of so-called atypical angina pectoris. There is no organic change of the heart of attention now. Recently it is said that so-called atypical angina pectoris is closely connected with paradoxical sleep. We recognized dysunction of the autonomic nervous system through various examinations. The hypothalamus was displaced upward by a suprasellar tumor in this case. After removal of the suprasellar tumor, the frequency of the attack of chest pain was decreased. The atypical angina pectoris in the presented case may be considered to consequence of distrubance of the hypothalamic function.