Purification and characterization of 5 beta-cholestane-3 alpha,7 alpha,12 alpha-triol 27-hydroxylase from female rat liver mitochondria

5 beta-Cholestane-3 alpha,7 alpha,12 alpha-triol 27-hydroxylase (5 beta-cholestane-3 alpha,7 alpha,12 alpha-triol, NADPH:oxygen oxidoreductase (26-hydroxylating), EC 1.14.13.15) was purified from female rat liver mitochondria based on its catalytic activity. The final preparation of the enzyme showed a single major band on the sodium dodecyl sulfate-polyacrylamide gel electrophoretogram. The content of purified enzyme was 12 nmol/mg of protein, and the specific activity was 431 nmol/min/mg of protein. The molecular weight of the enzyme was determined from sodium dodecyl sulfate-polyacrylamide gel electrophoresis as 52,500. The absorption spectra of the purified enzyme and that of the dithionite-reduced CO complex showed peaks at 417 and 450 nm, respectively, indicating the enzyme belongs to the cytochrome P-450 family. Upon reconstitution with the electron-transferring system of the adrenal (adrenodoxin and NADPH-adrenodoxin reductase), the enzyme showed high activity hydroxylating 5 beta-cholestane-3 alpha,7 alpha-12-triol at position 27 with a turnover number of 35.5 min-1 and Km of 6.3 microM. The enzyme activity was completely lost when the electron-transferring system was replaced by that of microsomes (NADPH-cytochrome P-450 reductase purified from rat liver microsomes), confirming that the P-450 enzyme was of the mitochondrial type, but not of the microsomal. The omission of cytochrome P-450, adrenodoxin, or NADPH-adrenodoxin reductase resulted in complete loss of enzyme activity. The specific activity toward 5 beta-cholestane-3 alpha, 7 alpha-diol was less than one-half that toward cholestanetriol and that toward cholesterol was about one-fiftieth. The enzyme showed no activity toward xenobiotics such as benzphetamine, 7-ethoxycoumarin, and benzo[a]pyrene. Its activity was not inhibited by metyrapone and slightly inhibited by aminoglutethimide. The enzyme activity was markedly lowered in an atmosphere of CO/O2/N2, 40/20/40.

Effect of LHRH agonist (buserelin) on pulsatile secretion of LHRH and LH

The LHRH agonist buserelin was administered intranasally to eight patients with endometriosis in doses of 300, 600 or 900 micrograms/day for six months. In all patients buserelin clearly suppressed ovulation. In the patients treated with 900 micrograms/day, estradiol levels declined to less than 30pg/ml, and LH release in response to LHRH testing decreased markedly after 2 months of treatment. A mild decrease in LH release was noted in the premarin test at the end of the treatment. At the end of buserelin treatment baseline levels of plasma LHRH, LHRH pulse amplitude and frequency were not lowered. However, baseline levels of plasma LH and LH pulse amplitude decreased. These results indicate that buserelin may act to decrease pituitary response to LHRH.

Light and electron microscopic study of the liver in paraquat poisoning

Intrahepatic cholestasis in paraquat poisoning in man has been thought to be secondary to extensive bile duct injuries, though its exact mechanism remains unsettled. We have examined liver biopsy specimens from two cases of paraquat poisoning. Case 1 (fatal) presented severe intrahepatic jaundice, and liver biopsy showed centrilobular cholestasis with extensive bile duct loss. Ultrastructurally, dilatation of bile canaliculi with decrease of microvilli and thickening of pericanalicular ectoplasm was found in the hepatocytes. Case 2 (alive) showed mild liver dysfunction without jaundice. While liver biopsy showed nonspecific reactive changes with intact bile ducts and ductules, electron microscopy disclosed dilatation of bile canaliculi with decrease of microvilli and thickening of pericanalicular ectoplasm in the hepatocytes, suggesting that damage to the bile secretory apparatus in the hepatocytes develops irrespective of extensive bile duct loss. These findings suggest that bile secretory apparatus in the hepatocytes as well as biliary epithelial cells could be a target of paraquat or its metabolites.

Effects of forskolin and cilostazol on clot retraction

We examined the effects of two inhibitors of aggregation of human platelets the, Forskolin and Cilostazol on clot retraction. Both substances suppressed clot retraction in a dose-dependent way. Both suppress platelet aggregation because of an increase in intercellular cyclic AMP, but there was no close correlations were shown between suppression rate for clot retraction and cyclic-AMP content in platelets in the clot in each substance. Furthermore, although it has been considered that actomyosin in platelets is a major contractile source for clot retraction and that failure of actin polymerization results suppression of clot retraction. As it was difficult to obtain active actin from platelets of the reagents on the polymerization. Cilostazol accelerated actin polymerization, whereas Forskolin did not. From these findings, it was considered that the effects of both substances on clot retraction could not be interpreted directly just by the increasing effect for intracellular cyclic-AMP. Clot retraction is consider to be a in vitro model of hemostasis and its contractile force is supplied from platelets (1,2,3). Experiments used prostaglandin E-1 revealed that elevation of cyclic-AMP (c-AMP) would regulate the clot retraction, and experiments used cytochalasin B demonstrated that actomyosin is responsible to the retraction (4,5). Many date demonstrate that elevation of c-AMP level suppresses platelet aggregation (6,7). c-AMP, therefore, should play a key role on platelet activation. Forskolin and Cilostazol are newly-developed reagents as a suppress for platelet functions. Pharmacological action of these substances have been interpreted to process increase effect for intracellular c-AMP of platelets(8,9). If so, both substances should show some effect on clot retraction. Under this assumption, we examined the effects.

The role of Bacteroides gingivalis in periodontal disease

The microbial flora in adult advanced periodontitis lesions is comprised of Gram-negative rods, with Bacteroides gingivalis as one of the major representatives. This review deals with biological properties of surface antigens, hemagglutinin (attachment factor), and capsular structure of B. gingivalis. Sera containing high IgG antibody levels to B. gingivalis enhanced the complement-mediated bactericidal activity in vitro, although the susceptibility to complement-mediated lysis differed among B. gingivalis strains. The protective effect of immunization against B. gingival is infection was examined in hamsters in which cotton threads had been tied to the gingival margins of the mandibular first molar. Repeated oral topical application of hyper-immune sera against B. gingivalis resulted in effective elimination of the organisms from the periodontal lesions in the experimental animals.

Purification and characterization of vitamin D 25-hydroxylase from rat liver mitochondria

Vitamin D 25-hydroxylase was purified from female rat liver mitochondria based on the catalytic enzyme activity. The final preparation of cytochrome P-450 was homogeneous judging from sodium dodecyl sulfate-polyacrylamide gel electrophoresis (Mr = 52,500). The specific content of the purified enzyme was 12 nmol/mg of protein. The absorption spectrum of the purified enzyme showed a peak at 417 nm and that of the dithionite-reduced CO complex at 450 nm, indicating the enzyme belongs to the cytochrome P-450 family. Upon reconstitution with the electron-transferring system of the adrenal system (adrenodoxin and NADPH-adrenodoxin reductase), the enzyme showed a high activity in hydroxylating 1 alpha-hydroxycholecalciferol at position 25 with a turnover number of 3.8 min-1 and Km of 54 microM. The enzyme activity was completely lost when the electron-transferring system was repLaced by that of microsomes (NADPH-cytochrome P-450 reductase purified from rat liver microsomes), confirming that the P-450 enzyme was of the mitochondrial type, not the microsomal type. The omission of cytochrome P-450, adrenodoxin, or NADPH-adrenodoxin reductase resulted in complete loss of enzyme activity. The liver mitochondrial cytochrome P-450 hydroxylates vitamin D3 and 1 alpha-hydroxyvitamin D3 at position 25, but did not show any activity toward xenobiotics such as benzphetamine, 7-ethoxycoumarin, and benzo[a]pyrene. The enzyme activity was not inhibited by aminoglutethimide but slightly inhibited by metyrapone. The enzyme activity was markedly inhibited in an atmosphere of CO:O2:N2, 40:20:40.

Suppressor T cells in mice made unresponsive to skin allografts

We have induced suppressor T cells (Ts), capable of delaying allogeneic skin graft rejection, through the intravenous administration of allogeneic spleen cells under normal conditions. H-2 and non-H-2 incompatibility between recipient mice and donor skins induced strong graft rejection. However, when the Ts were transferred into recipient mice, the mean survival time was prolonged for every combination between recipient mice and donor skin. Studies using several strains of congenic mice revealed the antigen specificity of these Ts. Treatment with monoclonal anti-Lyt-2.2 or anti-Thy-1.2 antibody and complement abolished the suppression shown by the Ts of skin graft rejection. The suppression induced by these Ts, however, was resistant to treatment with monoclonal anti-Lyt-1.2, anti-L3T4, or anti-I-A antibody and complement. These results showed that the Ts were Lyt-1-2+, L3T4-, Ia-, T cells.

Relationship between cardiac function and the sympathetic nervous system during exercise in patients with essential hypertension

The relationship between echographical cardiac function and sympathetic nerve activity during dynamic exercise was examined in patients with essential hypertension. Nine normotensives (Group N), 11 hypertensive patients without cardiac hypertrophy (Group NH) and 13 hypertensive patients with cardiac hypertrophy (Group HH) were studied during multistage exercise using a supine bicycle ergometer. The shortening fraction (SF) and the peak negative dD/dt in Group HH, being within the normal range, tended to be smaller than those in Group N at the 75-watt load. The mean value of the peak positive dD/dt (+dD/dt) in Group HH was significantly smaller than that in Group N at rest and during the 75-watt load. The percent increase of plasma norepinephrine (NE) levels (% delta NE) at the 75-watt load was significantly greater in Group HH than in Group N. Plasma NE, in some patients with cardiac hypertrophy and compromised cardiac function, markedly increased (% delta NE greater than or equal to 186) during exercise. % delta NE was directly related to the left ventricular mass index among all of the groups, but it was inversely related to the SF, -dD/dt, and to +dD/dt at the 75-watt load. We conclude that the augmented sympathetic nerve activity may contribute to preserving left ventricular systolic function during exercise within the normal range in hypertensive patients with cardiac hypertrophy.

[Morphometrical study on prognosis of stage I pulmonary adenocarcinoma]

The prognostic significance of morphometry in stage I pulmonary adenocarcinoma had been examined in Papanicolaou-stained bronchial brushings, using an image analyzer. The data of long-term survivors (LTS), alive for more than 5 years, and short-term survivors (STS), who had died within 5 years, were compared. LTS were found to have a smaller nuclear area, a shorter nuclear perimeter, and a smaller nucleolar area than those of the STS. The nuclear size is considered important in any histological subtypes. The variation index of the nuclear area, the nuclear circularity, and the number of nucleoli did not differ between the two groups. These results would seem to be useful in determining the prognosis and the indication type of adjuvant therapy to be used in surgical operations.

Effects of fluocinolone acetonide on mouse skin sterol metabolism and two-stage carcinogenesis

Fluocinolone acetonide (FA) is one of the most potent synthetic glucocorticoids and is known to possess an anti-tumor promoting activity. An attempt was made to evaluate this activity by estimating tumor promoting activity. Unexpectedly, when 10 micrograms of FA was applied alone or after a single application of a subcarcinogenic dose of 3-methylcholanthrene to mouse skin, results suggested that FA itself may be a tumor promoter or a complete carcinogen. Other glucocorticoids tested, e.g. dexamethasone, hydrocortisone and prednisolone, also revealed similar effects but were less potent than FA. To verify the possibility that glucocorticoid is a complete carcinogen or a tumor promoter, a tumor incidence experiment was performed for 24 weeks. As a result it was found that FA possesses a tumor promoting activity at some dose levels but no tumor initiating activity.

Plasma fructosamine assay in children with insulin-dependent diabetes mellitus

Plasma concentrations of fructosamine, an indicator of glycated plasma proteins, were measured in non-diabetic children and children with insulin-dependent diabetes mellitus (IDDM) to see if they also correlate with glycemic control in children as well as in adults. Non-diabetic children aged less than 4 yr had significantly lower plasma fructosamine than non-diabetic children aged 4 or more. Total plasma protein in these children was slightly lower or close to that of older children. There was no difference in fructosamine between non-diabetic children aged 4 or more and healthy adult subjects. Plasma fructosamine in children with IDDM was twofold that of age-matched controls. In children with IDDM, correlations between fructosamine and HbAI (r = 0.799) or HbAIc (r = 0.841) were high. The measurement of plasma fructosamine, which is practical in children because of the small sample volume needed and no influence of HbF, is useful in the management of children with IDDM.

A study of the central cavity in the bovine corpus luteum

Seven hundred and six bovine corpora lutea in various luteal stages were examined morphologically and endocrinologically to discover whether there is a relationship between the presence of a central cavity in the corpus luteum and infertility in cows. A central cavity was found in 42.1 per cent (80/190) of developing corpora lutea, 33.7 per cent (126/374) of fully developed corpora lutea, 11.1 per cent (7/63) of corpora lutea in regression and in 5.1 per cent (4/79) of corpora lutea in pregnancy. There was no significant difference between the rates of appearance of midcycle follicles in corpora lutea either with or without a central cavity. The proportion of luteal cell type 1 was higher in fully developed corpora lutea with a central cavity than without, but the reverse was found with luteal cell type 2. In fully developed corpora lutea the concentration of progesterone in the luteal tissue was significantly higher in corpora lutea with a central cavity. These results suggest that there are some differences in luteal function between corpora lutea with and without a central cavity, but that the presence of a central cavity in a corpus luteum cannot be described as a pathological condition.

Different distribution of decay-accelerating factor on hematopoietic progenitors from normal individuals and patients with paroxysmal nocturnal hemoglobinuria

Deficiency of decay-accelerating factor (DAF) occurs in blood cells in paroxysmal nocturnal hemoglobinuria (PNH), characterized by an unusual susceptibility to hemolysis by complement activation. This study examined DAF expression on hematopoietic progenitors from normal individuals and PNH patients using a fluorescence-activated cell sorter (FACS) with monoclonal antibodies to DAF. Nonphagocytic mononuclear marrow cells expressing different density distributions of DAF were sorted into DAF-, DAF+/-, DAF+, and DAF++ fractions. The cells from each fraction were cultured in methylcellulose and assayed for CFU-E, BFU-E, CFU-GM, and CFU-Mix. The percentages of distribution of DAF-negative normal progenitors increased in the order of CFU-E, CFU-GM, BFU-E, and CFU-Mix, whereas those of DAF-positive cells inversely decreased in this order. These results indicate that DAF expression may accompany differentiation from CFU-Mix to CFU-E. On the other hand, most progenitors in PNH patients had little, if any, expression of DAF on their cell surfaces. These findings were supported by another approach using a complement-dependent cytotoxicity method with the anti-DAF monoclonal antibodies. Abnormal expression of DAF was found on the progenitors in the bone marrow as well as on mature cells circulating in the blood in PNH.