[Jaundice with indirect bilirubinemia via the mother's milk]

Among the clinical entities included in the differential diagnosis of the prolonged jaundice at the end of neonatal period and in the small infant is the jaundice due to mother's milk, whose incidence is of 0.5-2% in the naturally fed infants. The authors present two cases in which the diagnosis was reached by exclusion and confirmed by the therapeutically positive test. Physiopathologic considerations are made on the basis of the literature data, and the nosologic background of the affection is presented. This clinical entity, considered to have an excellent prognosis, presented a special evolution in one of the cases.

Intramembraneous hydrogenation of mitochondrial lipids reduces the substrate availability, but not the enzyme activity of endogenous phospholipase A. The role of polyunsaturated phospholipid species

(1) Isolated rat liver mitochondria were subjected to catalytic hydrogenation using a water-soluble Pd complex and molecular H2. This treatment resulted in a reduction of double bonds on phospholipid acyl chains as judged by gas chromatography of fatty acid methyl esters and HPLC of dinitrobenzoyldiacylglycerols. (2) After hydrogenation, mitochondria lost their ability to hydrolyze endogenous phospholipids in alkaline, Ca2+ containing medium, while phospholipase A2 retained full activity against exogenous substrates, regardless of whether those substrates were hydrogenated or not. (3) Inhibition by hydrogenation of endogenous phospholipid hydrolysis correlated with the loss of polyunsaturated fatty acyls, rather than with changes of the bulk membrane fluidity as measured by ESR and fluorescence studies. (4) These data suggest that the unsaturation of mitochondrial membrane lipids might be important for regulation of phospholipid breakdown by endogenous phospholipases. In particular, polyunsaturated molecular species seem to be involved in making phospholipids accessible to phospholipase A-mediated hydrolysis.

Lipid peroxidation in Ehrlich ascites cell mitochondria is not determined by the polyunsaturated fatty acid content of the membrane

Lipid peroxidation intensity is compared in Ehrlich Ascites Cell and in liver mitochondria, prepared from tumor bearing mice. Malondialdehyde formation is negligible in intact ascites tumour mitochondria, but it is significantly increased in permeabilised mitochondria and in isolated mitochondrial membranes. We suggest that the resistance against oxidative stress is a consequence of efficient protective mechanisms operating in the intact tumour mitochondria and the low level of polyunsaturated fatty acids under these circumstances cannot be the rate limiting factor in lipid peroxidation. Succinate, an effective inhibitor of mitochondrial lipid peroxidation in liver, cannot determine malondialdehyde formation in ascites tumour mitochondria.

Lipid peroxidation in liver and Ehrlich ascites cell mitochondria

Ehrlich ascites cell mitochondria are highly resistant to lipid peroxidation as compared to liver mitochondria from host animals. Succinate protects mitochondria from peroxidative damage, proteins from cross-links, enzymes from inactivation of the enzymes and membranes from permeability changes. The sensitivity of Ehrlich ascites cell mitochondrial membranes to lipid peroxidation is significantly increased in submitochondrial particles. Lipid peroxidation in tumour mitochondrial membranes can not be diminished by succinate as effectively as in liver mitochondria. Ascites cell mitochondria seems to be protected very efficiently from peroxidative damage by a glutathione-dependent mechanism.

Mechanism of hemoglobin-induced spasm in the isolated middle cerebral artery of the cat

a./Great regional differences were observed in the vasospastic effect of hemoglobin. Namely, hemoglobin was far more potent in the middle cerebral artery than in the mesenteric artery. b./The role of potassium ions as well as activation of calcium mobilizing adrenergic, serotoninergic and PGF2 alpha smooth muscle receptors were excluded in the mechanism of cerebral vasospasm induced by hemoglobin. c./First in the literature we showed that atropine significantly attenuates the vasospastic effect of hemoglobin, and hemoglobin releases peptidergic neurotransmitters and modulators from nerve terminals that are located in the adventitia of the middle cerebral artery.

The effect of EDTA-Fe(III) complexes with different chemical structure on the lipid peroxidation in brain microsomes

Unlike EDTA-Fe(III) (1:1), the oxidized form of EDTA-Fe(II) complex enhanced lipid peroxidation in brain microsomes. Mossbauer spectroscopy and electron paramagnetic resonance analysis of oxidized EDTA-Fe(II), capable of inducing lipid peroxidation, showed the presence of EDTA-Fe(III) complex, which was different from the separately prepared (not oxidized) EDTA-Fe(III). Lipid peroxidation initiated by the oxidized EDTA-Fe(II) complex was dependent on the presence of NAD(P)H and functionally intact microsomes. No inhibitory effect was found by generally used free radical scavengers and catalase. Our results clearly indicate that the chemically different EDTA-Fe(III) complexes differ in their capability of initiating the NAD(P)H-dependent lipid peroxidation in brain microsomes.

The inhibitory effect of succinate on radiation-enhanced mitochondrial lipid peroxidation

The degree of mitochondrial ADP/Fe/NADPH-induced lipid peroxidation was increased up to the fourth day after 9.0 Gy whole body gamma-irradiation. The lipid peroxidation inhibiting effect of succinate added to isolated mitochondria was diminished as a consequence of irradiation. The succinate, administered in vivo prior to irradiation, decreased the amount of malondialdehyde production and protected the succinate dehydrogenase enzyme against inactivation. The mean survival of succinate-pretreated animals was much longer than that of controls. The role of mitochondrial lipid peroxidation in the pathogenesis of radiation injury is discussed.

Experimental syphilis and serological examination for treponematosis in hares

Of 202 captive hares studied, many of which had lesions on their external genital organs or testicular atrophy or both, 27% had positive serological tests for syphilis although dark-field examination of extracts of atrophic testes was negative. A total of 12 hares that were nonreactive for the serological test for syphilis was inoculated with Treponema pallidum, 9 intratesticularly and 3 intradermally. Six of the animals inoculated intratesticularly exhibited orchitis after 7 days with an associated accumulation of treponemes. No chancres developed in the intracutaneously inoculated animals during a 27-day period of observation. These results provide additional evidence to support the contention that endemic treponematosis occurs in wild hares and suggest that hares are moderately resistant to experimental infection with T. pallidum.

Isolation of pathogenic treponemes from hare

A presumably new species of pathogenic treponemes was isolated from a lesion on the male organs of hare (Lepus sp.) and the scrotum of a rabbit (Oryctolagus sp.) was infected with this treponeme. Lesion developed on the scrotum after a 110-day incubation.

Effects of oxygen and nitrogen on the character of T. pallidum is subcutaneous chambers in mice

Nitrogen and oxygen gases were injected into mouse subcutaneous chambers which contained virulent Treponema pallidum. The effect of each gas on the viability and survival of T. pallidum in an in vivo system was determined. In comparison with the effects in nontreated control mice, injection of nitrogen enhanced both motility and survival time, but oxygen exerted a deleterious effect.

Induced phenotypic resistance to valine in Mycobacterium pellegrino

Valine coordinately increases the levels of three of the enzymes participating in the biosynthesis of isoleucine and valine in Mycobacterium pellegrino. The amount of valine required for end-product induction depends on the condition of the cells. Isoleucine inhibits the effect of valine. Acetohydroxy acid synthetase, the enzyme catalyzing the first common step in the biosynthesis of valine and isoleucine, is inhibited by valine. The induction effect of valine appears to be due to its ability to inhibit the activity of this enzyme, thus causing isoleucine deficiency, which in turn leads to derepression. This conclusion is supported by the fact that valine, under certain conditions, inhibits growth.