P6283Downregulation of Tim44 exacerbates oxidative stress-induced ROS production and cardiomyocytes death by reducing mitochondrial SOD2

Background

Mitochondrial dysfunction has been highlighted as a critical driver of cardiac remodeling and failure. Mitochondria contains about 1500 proteins, 99% of which are encoded in the nuclear genome. Therefore, protein import into mitochondria is essential to maintain mitochondrial function. Previous reports suggest that nuclear-encoded mitochondrial precursor proteins import into mitochondria by multiple complex; translocase of outer membrane (TOM), translocase of inner membrane (TIM), and protein associated motor (PAM). However, the role of these protein import machineries of mitochondria in cardiac remodeling remains to be elucidated.

Objective

The purpose of this study was to elucidate the role of TOM, TIM, and PAM complex in cardiac remodeling and cardiomyocyte death.

Methods and results

C57BL/6J mice were subjected to myocardial infarction (MI) by permanent ligation of left anterior descending artery. Four weeks after operation, MI-mice demonstrated left ventricular (LV) dilation (LV end-diastolic dimension: 3.91 vs. 5.54 mm, n=8–11, p<0.05) and dysfunction (LV fractional shortening: 33.3 vs. 7.7%, n=8–11, p<0.05). Tim44 protein levels, a component of PAM complex, in mitochondrial fraction from non-infarcted left ventricle were significantly decreased compared with those in the heart from sham-operated mice by 39% (p<0.05), whereas other proteins related to TOM, TIM and PAM complex such as Tom20, Tom22, Tom40, Tom70, Tim22, Tim23 and mtHSP70 were not altered between MI-mice and sham-mice. In addition, blue-native polyacrylamide gel electrophoresis revealed that a protein complex associated to Tim44 was significantly decreased in non-infarcted LV by 40% (p<0.05). Superoxide dismutase 2 (SOD2), a mitochondrial matrix protein, was decreased in mitochondrial fraction from non-infarcted LV by 20% (p<0.05), accompanied by enhancing protein carbonylation, a marker of oxidative stress, by 40% (p<0.05). To assess the role of Tim44, it was downregulated by small interfering RNA in cultured neonatal rat ventricular myocytes (NRVMs). Knockdown of Tim44 significantly decreased SOD2 protein levels in mitochondrial fractionation (22%, p<0.05), with no significant changes in its mRNA levels. Furthermore, knockdown of Tim44 significantly increased protein carbonylation (20%, p<0.05) and cleaved caspase 3 (47%, p<0.05) and decreased cell viability (69%, p<0.05), assessed by cell titer assay, in H2O2-treatred NRVMs.

Conclusions

Downregulation of Tim44 exacerbates oxidative stress-induced ROS production and cardiomyocytes death, which is associated with a decrease in mitochondrial SOD2. Endogenous Tim44 might play a protective role in cardiac remodeling by attenuating oxidative stress and cardiomyocyte death via SOD2 import into mitochondria.

P1606Glutamine-fructose-6-phosphate amidotransferase 2 mediates isoproterenol-induced cardiac hypertrophy by increasing Akt O-GlcNAcylation through hexosamine biosynthesis pathway

Background

Cardiac hypertrophy is an independent risk factor for heart failure and cardiac death. Hexosamine biosynthesis pathway (HBP), an accessory pathways of glycolysis, is known to be involved in the attachment of O-linked N-acetylglucosamine motif (O-GlcNAcylation) to proteins, a post-translational modification. However, the role of HBP has not been determined in pathological cardiac hypertrophy.

Purpose

The purpose of this study to examine whether glutamine-fructose-6-phosphate amidotransferase 2 (GFAT2), a critical enzyme of HBP, mediates cardiac hypertrophy by protein O-GlcNAcylation and activating hypertrophic signaling in cardiomyocytes.

Methods and results

C57BL/6J mice were treated with isoproterenol (ISO: 15 mg/kg/day, 1 week) with or without 6-Diazo-5-oxo-L-norleucine (DON, an inhibitor of GFAT: 500 μg/kg/day, 1week). ISO-treated mice (ISO+vehicle) showed cardiac hypertrophy, which were attenuated in ISO and DON-treated mice (ISO+DON) (heart weight to tibial length ratio: 7.70±0.09 vs. 7.11±0.15 mg/mm, n=12, p<0.05, left ventricular wall thickness: 1.05±0.02 vs. 0.86±0.03 mm, n=6, p<0.05). Cardiomyocyte cross-sectional area was also decreased in ISO+DON compared with ISO+vehicle (309±25 vs. 252±13 mm2, n=,3 p<0.05). Whereas expression levels of GFAT2 and protein O-GlcNAcylation in the heart were increased in ISO+vehicle compared with control+vehicle by 3.3 and 1.5 folds, respectively (n=9 and n=9, p<0.05), expression levels of O-GlcNAc transferase (OGT) and the β-N-acetylglucosaminidase (OGA), other enzymes regulating O-GlcNAcylation, were not altered in both groups, indicating that ISO activated HBP by GFAT2. Protein O-GlcNAcylation in ISO+DON was lower than that in ISO+vehicle by 83% (n=9, p<0.05). In addition, phosphorylation of Akt, a critical mediator of cardiac hypertrophy, but not other mediators of cardiac hypertrophy such as ERK, JNK, or p38MAPK, was significantly decreased in ISO+DON by 76% (n=9, p<0.05). In cultured neonatal rat ventricular myocytes, treatment with ISO (1μM, 12h) increased the expression levels of GFAT2 and protein O-GlcNAcylation by 1.3 and 1.5 folds, respectively (n=6 and n=6, p<0.05), but not GFAT1. Furthermore, ISO stimulation increased a direct O-GlcNAcylation of Akt by 1.4 folds (n=3, p<0.05). Downregulation of GFAT2 by RNA silencing decreased cell size by 82% (n=6, p<0.05) and protein O-GlcNAcylation and phosphorylation of Akt by 76% and 54%, respectively (n=9 and n=9, p<0.05) in cardiomyocyte treated with ISO. Conversely, administration of glucosamine, a substrate of HBP, increased protein of O-GlcNAcylation and phosphorylation of Akt by 1.3 and 1.8 folds, respectively (n=6 and n=6, p<0.05).

Conclusions

GFAT2, a limiting enzyme of HBP, mediates pathological cardiac hypertrophy by Akt activation probably due to its O-GlcNAcylation. GFAT2-O-GlcNAcylation-Akt pathway might be a potential novel therapeutic target for cardiac hypertrophy.

P6305Activation of invariant natural killer T cells ameliorates doxorubicin-induced cardiomyopathy

Background

Invariant natural killer T (iNKT) cells orchestrate tissue inflammation via regulating various cytokine productions, especially strongly upregulating interferon (IFN)-γ. Activation of iNKT cells have been previously reported to exert protective effects against post-infarcted cardiac remodeling and cardiac ischemia/reperfusion injury. However, the role of iNKT cells has not been determined in doxorubicin (DOX)-induced cardiomyopathy.

Purpose

The purpose of this study was to examine whether the activation of iNKT cells by α-galactosylceramide (αGC), which specifically activates iNKT cells, could affect DOX-induced cardiomyopathy, and if so, to elucidate its downstream target.

Methods

C57BL/6J mice were received the intraperitoneal injection of either αGC (0.1μg/g, n=11) or vehicle (n=13). After 1 week, these mice were treated with a low dose of DOX (18mg/kg via intravenous 3 injections over 1 week), and were followed during 14 days.

Results

DOX mice (DOX+vehicle) showed left ventricular (LV) dysfunction and dilatation, which were significantly ameliorated in DOX mice receiving αGC (DOX+αGC) (LV fractional shortening: 27.4±4.31 vs. 31.5±4.62%, p<0.05, LV end-diastolic diameter: 3.70±0.16 vs. 3.32±0.23mm, p<0.05), with no significant changes in arterial pressure, body weight, and food consumption, 14 days after DOX injection. DOX+vehicle demonstrated a significant decrease in myocardial gene expression of Vα14Jα18, a specific marker of iNKT cells, and IFN-γ compared with control mice. Vα14Jα18 expression levels were higher in DOX+αGC than DOX+vehicle by 9.2 folds (p<0.05). Consistent with this change, IFN-γ was higher in DOX+αGC than DOX+vehicle by 4.4 folds (p<0.05), whereas interleukin (IL)-1, IL-4, IL-6, IL-10, IL-17, IL-23, and tumor necrosis factor (TNF)-α were not altered in both groups. Phosphorylation of Akt, its active form, in the heart was significantly increased in DOX+αGC compared with DOX+vehicle by 1.8 folds (p<0.05).

Conclusions

Activation of iNKT cells by αGC play a protective role against DOX-induced cardiac dysfunction, which was associated with enhancing expression of IFN-γ and activating Akt. Therapies designed to activate iNKT cells might be beneficial to protect the heart from DOX injury.

Non-invasive diffuse reflectance measurements of cutaneous melanin content can predict human sensitivity to ultraviolet radiation

The diversity of human skin phenotypes and the ubiquitous exposure to ultraviolet radiation (UVR) underscore the need for a non-invasive tool to predict an individual's UVR sensitivity. We analysed correlations between UVR sensitivity, melanin content, diffuse reflectance spectroscopy (DR) and UVR-induced DNA damage in the skin of subjects from three racial/ethnic groups: Asian, black or African American and White. UVR sensitivity was determined by evaluating each subject's response to one minimal erythemal dose (MED) of UVR one day after the exposure. Melanin content was measured using DR and by densitometric analysis of Fontana-Masson staining (FM) in skin biopsies taken from unexposed areas. An individual's UVR sensitivity based on MED was highly correlated with melanin content measured by DR and by FM. Therefore, a predictive model for the non-invasive determination of UVR sensitivity using DR was developed. The MED precision was further improved when we took race/ethnicity into consideration. The use of DR serves as a tool for predicting UVR sensitivity in humans that should be invaluable for determining appropriate UVR doses for therapeutic, diagnostic and/or cosmetic devices.

Whitening efficacy of plant extracts including orchid extracts on Japanese female skin with melasma and lentigo senilis

The purpose of this study was to assess the in vivo efficacy of a cosmetic formulation containing plant extracts including orchid extracts, compared to 3% vitamin C derivative formulated with the same excipient, in Japanese female adult volunteers with melasma and/or lentigo senilis. The ethics committee of Osaka National Hospital approved the protocol of the study. Before recruitment, selection and inclusion of a volunteer in this study, signed informed consent was obtained from each volunteer after she was given clear and precise information on the study, enabling her to appreciate the aim of the study and the consequences of her consent. Forty-eight female volunteers aged 30-60 years applied the plant extracts and vitamin C derivative to one side of the face. After repeated application for 8 weeks, efficacy was evaluated clinically by colorimetric measurements and subjectively using a questionnaire. After 8 weeks of treatment, both the clinical evaluations by a dermatologist and the questionnaire surveys by volunteers indicated that the cosmetic formulation containing plant extracts was significantly effective in improving the size, brightness, color intensity, clarity, visibility and global appearance of the pigmented spots, and also the luminosity complexion and skin clarity of the face. The good agreement between the results of clinical evaluations and those of questionnaire surveys showed that the orchid-rich plant extracts possess efficacy similar to vitamin C derivative in whitening the skin as well as melasma and lentigo senilis on the face of Japanese women.

Expression of estrogen receptor beta in normal skin, melanocytic nevi and malignant melanomas

Sex hormones are known to be associated with increases of melanocytes and melanin production in human skin. However, the expression of estrogen receptor (ERalpha) in melanocytic lesions has been controversial. In 1996, a new subset of estrogen receptor was cloned, and named estrogen receptor beta (ERbeta). We used immunohistochemical staining to characterize the expression of ERalpha and ERbeta in normal skin and in melanocytic lesions. Normal sebaceous glands and hair follicles were positive for ERalpha and ERbeta. Other adnexal structures and constituents in the skin were positive for ERbeta, but not for ERalpha. Melanocytic nevi and malignant melanomas were negative for ERalpha, but both were positive for ERbeta. The ubiquitous expression of ERbeta may play a fundamental role in various normal skin cells and melanocytic tumors.

Human skin responses to UV radiation: pigment in the upper epidermis protects against DNA damage in the lower epidermis and facilitates apoptosis

Melanin plays an important role in protecting the skin against UV radiation, and melanomas and basal/squamous cell carcinomas occur more frequently in individuals with fair/light skin. We previously reported that levels of melanin correlate inversely with amounts of DNA damage induced by UV in normal human skin of different racial/ethnic groups. We have now separately examined DNA damage in the upper and lower epidermal layers in various types of skin before and after exposure to UV and have measured subsequent apoptosis and phosphorylation of p53. The results show that two major mechanisms underlie the increased photocarcinogenesis in fair/light skin. First, UV-induced DNA damage in the lower epidermis (including keratinocyte stem cells and melanocytes) is more effectively prevented in darker skin, suggesting that the pigmented epidermis is an efficient UV filter. Second, UV-induced apoptosis is significantly greater in darker skin, which suggests that UV-damaged cells may be removed more efficiently in pigmented epidermis. The combination of decreased DNA damage and more efficient removal of UV-damaged cells may play a critical role in the decreased photocarcinogenesis seen in individuals with darker skin.

Mechanisms of Skin Tanning in Different Racial/Ethnic Groups in Response to Ultraviolet Radiation

Ultraviolet radiation stimulates pigmentation in human skin, but the mechanism(s) whereby this increase in melanin production (commonly known as tanning) occurs is not well understood. Few studies have examined the molecular consequences of UV on human skin of various racial backgrounds in situ. We investigated the effects of UV on human skin of various races before and at different times after a single 1 minimal erythemal dose UV exposure. We measured the distribution of DNA damage that results, as well as the melanin content/distribution and the expression of various melanocyte-specific genes. The density of melanocytes at the epidermal:dermal junction in different types of human skin are remarkably similar and do not change significantly within 1 wk after UV exposure. The expression of melanocyte-specific proteins (including TYR (tyrosinase), TYRP1 (tyrosinase-related protein 1), DCT (tyrosinase-related protein 2), MART1 (melanoma antigens recognized by T-cells) gp100 (Pmel17/silver), and MITF (micropthalmia transcription factor)) increased from 0 to 7 d after UV exposure, but the melanin content of the skin increased only slightly. The most significant change, however, was a change in the distribution of melanin from the lower layer upwards to the middle layer of the skin, which was more dramatic in the darker skin. These results provide a basis for understanding the origin of different skin colors and responses to UV within different races.

Mechanisms of skin tanning in different racial/ethnic groups in response to ultraviolet radiation

Ultraviolet radiation stimulates pigmentation in human skin, but the mechanism(s) whereby this increase in melanin production (commonly known as tanning) occurs is not well understood. Few studies have examined the molecular consequences of UV on human skin of various racial backgrounds in situ. We investigated the effects of UV on human skin of various races before and at different times after a single 1 minimal erythemal dose UV exposure. We measured the distribution of DNA damage that results, as well as the melanin content/distribution and the expression of various melanocyte-specific genes. The density of melanocytes at the epidermal:dermal junction in different types of human skin are remarkably similar and do not change significantly within 1 wk after UV exposure. The expression of melanocyte-specific proteins (including TYR (tyrosinase), TYRP1 (tyrosinase-related protein 1), DCT (tyrosinase-related protein 2), MART1 (melanoma antigens recognized by T-cells) gp100 (Pmel17/silver), and MITF (micropthalmia transcription factor)) increased from 0 to 7 d after UV exposure, but the melanin content of the skin increased only slightly. The most significant change, however, was a change in the distribution of melanin from the lower layer upwards to the middle layer of the skin, which was more dramatic in the darker skin. These results provide a basis for understanding the origin of different skin colors and responses to UV within different races.

Melkersson-Rosenthal syndrome caused by saprodontia: a case report

A 24-year-old female patient with Melkersson-Rosenthal syndrome (MRS) in association with saprodontia is reported. She presented with lower labial swelling and left facial edema. Histological examination of the involved oral mucosa showed a noncaseating epithelioid granuloma. Results from the laboratory and imaging examinations were normal or negative. Her orofacial swelling disappeared after treatment of the saprodontia of the left first molar.

The inhibitory effect of androgen and sex-hormone-binding globulin on the intracellular cAMP level and tyrosinase activity of normal human melanocytes

The effect of androgens on human melanocytes has not been well clarified. We studied the effects of androgens on normal human melanocytes in the presence or absence of sex-hormone-binding globulin (SHBG), which complexes with those hormones. Immunohistochemically, testosterone and SHBG co-localized on the cell membrane. Androgens such as testosterone, 5alpha-dihydrotestosterone, and methyltrienolone (R1881, a potent synthetic androgen), reduced intracellular cAMP levels after treatment with SHBG, but hydrocortisone had no effect. We also found that testosterone and R1881 slightly suppressed tyrosinase activity in melanocytes when treated with SHBG, although they had no effect on the expression of tyrosinase at the transcriptional or translational level, as measured by semi-quantitative reverse transcriptase-polymerase chain reaction and by Western blot analysis, respectively. Our results suggest that androgens may modulate tyrosinase activity at the posttranslational level through the cell membrane signaling pathway.

UV-induced DNA damage and melanin content in human skin differing in racial/ethnic origin

DNA damage induced by UV radiation is a critical event in skin photocarcinogenesis. However, the role of racial/ethnic origin in determining individual UV sensitivity remains unclear. In this study, we examined the relationships between melanin content and DNA damage induced by UV exposure in situ in normal human skin of different racial/ethnic groups, phototypes, and UV sensitivities. The minimal erythema dose (MED) was established for each subject exposed to UVA/UVB radiation, and skin was biopsied before as well as 7 min, 1 day, and 1 wk after UV exposure. There was great variation among individuals in the amount of DNA damage incurred and rates of its removal. The results show that after exposure to 1 MED of UV, the skin of subjects from all groups suffered significant DNA damage, and that increasing content of constitutive melanin inversely correlated with the amount of DNA damage. It is clear from these results that measured erythemal UV sensitivity of the skin (MED) is a more useful predictor of DNA photodamage than is racial/ethnic origin or skin phototype and that rates of DNA damage removal following UV radiation may be the critical determinant of the UV sensitivity (including predisposition to cancer) of the skin.

Vitamin B-12-deficiency affects immunoglobulin production and cytokine levels in mice

To clarify the role of B-12 in the immunological function, serum C3, IgM, IgG, IgE contents, splenocytes expression of CD4, CD8, and CD4 positive intracellular IFN-gamma and IL-4 were examined in B-12-deficient mice, and the effect of the administration of CH3-B-12 was also studied. Serum C3, IgM and IgG contents were lower in B-12-deficient mice than in the control mice. On the other hand, serum IgE content was significantly higher in B-12-deficient mice, and the value in CH3-B-12 administered mice, administered CH3-B-12 to B-12-deficient mice for 48 h before the end of feeding period, showed a tendency to recovery. CD4+CD8- cells and CD4+CD8-/CD4-CD8+ ratio in splenocytes were significantly higher in B-12-deficient mice than in control mice. CD4+IFN-gamma+ cells was significantly lower in B-12-deficient mice than in control mice, and CD4+IL-4+ was significantly higher in B-12-deficient mice than in control mice. These results suggest that B-12-deficiency causes CD4+CD8-T cells shift from the T helper type 1 to the T helper type 2, which participate in the IgE production and elevates CD4+CD8-/CD4-CD8+ ratio. Thus, B-12 plays a role in maintaining the immune function in mice.

Effect of cobalamin on the allergic response in mice

Cyanocobalamin, deoxyadenosylcobalamin and methylcobalamin were separately administered to mice sensitized with the ovalbumin antigen to investigate the allergic response. The serum IgE and pulmonary histamine concentrations were significantly lower in all cobalamin (Cbl)-administered groups. The production of interleukin (IL)-2 and IL-4 in splenocytes was also lower in all Cbl-administered groups. These results show that Cbls were effective in mitigating allergic reactions and IL-2 production. CD3+ CD28+ (CD28 is an accessory molecule related to IL-2 production) and CD4+ CD28+ in splenocytes were higher in all the Cbl-administered groups. However, CD3+ CD28-, CD4+ CD28- and CD5+ CD25- (CD25: IL-2 R alpha/p55) were lower in the Cbl-administered groups. In addition, Cbl specifically inhibited the cellular phosphorylation of tyrosine induced by ovalbumin sensitization. These results indicate that the signal in a cell by CD 28 was restrained by Cbl. We infer that Cbl administration significantly reduced the IL-2 concentration, and secondarily the IL-4, IgE and histamine concentrations.

Extremely low activity of methionine synthase in vitamin B-12-deficient rats may be related to effects on coenzyme stabilization rather than to changes in coenzyme induction

Severely vitamin B-12 (B-12)-deficient rats were produced by feeding a B-12-deficient diet. The status of B-12 deficiency was confirmed by an increase in urinary methylmalonate excretion and decreases in liver B-12 concentrations and cobalamin-dependent methionine synthase activity. Rat liver methionine synthase existed almost exclusively as the holoenzyme. In B-12-deficient rats, the level of methionine synthase protein was lower, although the mRNA level was not significantly different from that of control rats. When methylcobalamin, the coenzyme for methionine synthase, was administered to the B-12-deficient rats, growth, liver B-12 concentrations and urinary excretion of methylmalonate were reversed although not always to control (B-12-sufficient) levels in a short period. During this recovery process, methionine synthase activity and its protein level increased, whereas the mRNA level was unaffected. We reported previously that rat apomethionine synthase is very unstable and is stabilized by forming a complex with methylcobalamin. Thus, the extremely low activity of methionine synthase in B-12-deficient rats may be related to effects on "coenzyme stabilization" (stabilization of the enzyme by cobalamin binding) rather than to changes in "coenzyme induction."

Preferential incorporation of docosahexaenoic acid into nonphosphorus lipids and phosphatidylethanolamine protects rats from dietary DHA-stimulated lipid peroxidation

In a previous study, we found that dietary docosahexaenoic acid (DHA)-stimulated tissue lipid peroxide formation was suppressed to a lesser extent than expected from the peroxidizability index of tissue total lipids. This suppression was presumed to be potentiated by mechanisms other than the lipid peroxide-scavenging system. In this study, we focused primarily on the incorporation of DHA into tissue nonphosphorus lipids and phospholipid species. DHA and different levels of dietary vitamin E (VE; 7.5, 54, 134 and 402 mg/kg of diet) were fed to rats for 32 d. In rats with poor VE status, liver chemiluminescence intensity and kidney and testis thiobarbituric acid (TBA) values correlated with the tissue's peroxidizability index. In rats with normal VE nutriture, liver lipid peroxide formation was suppressed to a level below that expected from the peroxidizability index, likely because DHA was present in nonphosphorus lipids and utilized preferentially for phosphatidylethanolamine synthesis. In the kidney, differences in the TBA values were associated with differences in the peroxidizability index of total lipids, even in the DHA groups fed VE at higher than normal levels. This may be because the levels of lipid peroxide scavengers were lower than those of liver and because DHA was utilized preferentially for phosphatidylcholine synthesis. In testis, the lipid peroxide levels were not as high as expected from the peroxidizability index, even in rats fed a high DHA diet containing the normal level of VE. This may be because the testis was composed of a high proportion of (n-6) polyunsaturated fatty acids (PUFA), which are low in unsaturation, and thus the proportion of DHA was low. In addition, in testis, VE and ascorbic acid, which act as antioxidants, were retained at higher levels in rats with particularly poor and normal VE nutriture than those of liver and kidney. These results suggest that antioxidant protection against dietary DHA-stimulated lipid peroxidation below the extent expected from the peroxidizability index of tissue total lipids differed from tissue to tissue. The suppression was likely due to not only the lipid peroxide scavenging system but also preferential incorporation of DHA into nonphosphorus lipids and phosphatidylethanolamine, particularly in liver.

Changes in CD4+CD8-/CD4-CD8+ ratio and humoral immune functions in vitamin B12-deficient rats

To clarify the role of vitamin B12 in the function of cell-mediated and humoral immune functions, the splenocytes expression of CD4, CD8 and serum C3, IgM, IgG concentrations were examined in vitamin B12-deficient rats, and the effect of the administration of methylcobalamin was also studied. The CD4+CD8-/CD4-CD8+ ratio in splenocytes was significantly higher in vitamin B12-deficient rats than in control rats (p < 0.05). The value in the 48 hours after methylcobalamin administration group, was within the normal range (p < 0.05). From these results, the elevation of the CD4+CD8-/CD4-CD8+ ratio by vitamin B12-deficiency was confirmed in rats. The serum C3, IgM and IgG concentrations were lower in the vitamin B12-deficient group than in the control group. These findings suggest that vitamin B12 plays a role in maintaining the immune function in rats.

A repeat-batch membrane bioreactor with a phase inversion for the desaturation of isopropyl palmitate by a mutant Rhodococcus strain

A repeat-batch membrane bioreactor was constructed for the novel bioconversion of isopropyl hexadecanoate to isopropyl cis-6-hexadecenoate by a Rhodococcus mutant. The addition of glutamate, thiamine, and MgSO(4) was very effective in improving not only the rate and yield of the bioconversion but also the maintenance of desaturation activity during cell recycling. An oil-in-water (O/W) type emulsion of the reaction medium was inverted to a water-in-oil (W/O) type by discharging the water phase from the reaction mixture. The continuous oil phase containing the product could effectively be recovered through a hydrophobic hollow-fiber module. By decreasing the oil-to-water ratio upon addition of fresh medium, the medium was spontaneously inverted again to an O/W type emulsion to proceed with the next conversion. The batch reaction coupled with the phase inversion could be repeated more than 13 times for over about 300 h operation. Finally, a highly purified product was obtained with high yield by the urea adduct procedure.

Double involvement of extramammary Paget's disease in the genitalia and axilla

We here reported a case of an 82-year-old man with double involvement of extramammary Paget's disease in the genitalia and axilla. Physical examination revealed erythema and reddish tumors on the pubic area and scrotum and irregular-shaped erythema on the left axilla. The skin biopsy sample from the genital area showed Paget's cells in the epidermis and upper dermis. The specimen from the left axilla showed Paget's cells scattered in the epidermis but not in the dermis.

Minoxidil increases 17 beta-hydroxysteroid dehydrogenase and 5 alpha-reductase activity of cultured human dermal papilla cells from balding scalp

Minoxidil is known to induce hair growth in male pattern baldness, for which development androgen plays a central role. We studied the effect of minoxidil on testosterone metabolism by cultured dermal papilla cells from balding or nonbalding scalp and dermal fibroblasts. In all three groups, 17beta-hydroxysteroid dehydrogenase activity was much higher than 5alpha-reductase activity. Minoxidil increased 17beta-hydroxysteroid dehydrogenase activity by nearly 40% (P < 0.001) in dermal papilla cells of balding scalp, whereas the effect was less marked in dermal papilla cells from nonbalding scalp and dermal fibroblasts. 5alpha-Reductase activity was also slightly increased by minoxidil in dermal papilla cells from balding scalp. Again, the effect on 5alpha-reductase activity was insignificant in the other two groups of cells. Whether such modification of testosterone metabolism in dermal papilla cells of balding scalp by minoxidil is related to its therapeutic effect remains unknown.

Dietary docosahexaenoic acid dose not promote lipid peroxidation in rat tissue to the extent expected from peroxidizability index of the lipids

Docosahexaenoic acid (DHA) ingestion enhanced the susceptibility of rat liver and kidney to lipid peroxidation as a function of the dietary DHA level, but did not increase lipid peroxides as assessed by thiobarbituric acid (TBA) values to the level expected from the peroxidizability index of the tissue total lipids. This phenomenon was especially prominent in the liver. In the liver, the higher proportion of DHA in the non-phosphorus lipids might play an important role in lessening the susceptibility of the tissue to lipid peroxidation. In the brain and testis, on the other hand, lipid peroxide levels were decreased when DHA was given to the animals. In the testis, in particular, the proportion of DHA in total lipids was lowest among all tissues examined, even when a relatively high level of DHA had been ingested, and this could be related to the low lipid peroxide level. Therefore, the protection against lipid peroxidation differed from tissue to tissue, even from the viewpoint of the fatty acid composition of the tissue lipids. In addition, changes in the lipid peroxide levels of the liver, kidney, brain and testis, as assessed by TBA values, seemed to be associated with changes in the peroxidizability index of phosphatidylcholine (+cardiolipin) in each tissue.

Growth stimulation of normal melanocytes and nevocellular nevus cells by gastrin releasing peptide (GRP)

In order to know the possible effects of gastrin releasing peptide (GRP) on nevus cells and melanocytes, we studied the effect of GRP on the proliferation of cultured human nevus cells and normal melanocytes. MTS assay showed that GRP stimulated the growth of viable melanocytes at 1000 ng/ml. GRP also stimulated the growth of nevus cells in a dose dependent manner and maximum stimulation was obtained at 100 ng/ml of GRP. GRP was less effective for growth stimulation of normal melanocytes than nevus cells. The cytoplasm of nevus cells were positively stained by polyclonal anti-GRP antibody. We also detected the expression of GRP and GRP receptor mRNAs in these cells by RT-PCR. These results suggest that GRP acts as an autocrine growth factor for nevus cells and normal melanocytes.

Serum C3 content in vitamin B(12)-deficient rats

As a clue to clarifying the role of vitamin B12 (B12) in the function of the complement system, serum C3 content was determined in B12-deficient rats, and the effect of the administration of methylcobalamin (CH3-B12) on the serum C3 content was also studied. It was found that the serum C3 content in rats fed on a vitamin B12-deficient diet for 90 and 120 days significantly decreased compared with that in control rats. The administration of CH3-B12) restored the serum C3 content to control levels. The above results indicate that B12-deficiency depressed the serum C3 content and lowered humoral immunocompetence, and that these changes were ascribable to B12-deficiency.

Histochemical observation and cellular distribution of ascorbic acid in persimmon leaves

This study was carried out to resolve the discrepancy of data for the proportion of ascorbic acid and dehydroascorbic acid in persimmon leaves at the final stage of the season and to clarify their cellular distributions using histochemical and biochemical techniques. Fresh persimmon leaves were collected and used on July 31, September 5 and October 7, 1996. Ascorbic acid and dehydroascorbic acid in subcellular fractions were determined by the HPLC method that was found to be the most reliable for separation. The percent of dehydroascorbic acid in the total leaves was found to be almost constant (between 32 and 37%) in all preparations tested. In all preparations, more than 90% of the ascorbic acid and dehydroascorbic acid was found in the soluble fraction. The histochemical detection of ascorbic acid and an electron micrograph of persimmon leaf cells showed that the reactive color, after the reduction of silver nitrate under acidic conditions, in the leaves of all three preparations was mainly found on the face side of columned-type palisade parenchyma cells where chloroplasts were not rich and large vacuoles were seen. On the inner side of the palisade parenchyma cells where chloroplasts were the richest, only weak color development was observed. This study demonstrates that the percent of dehydroascorbic acid in persimmon leaves did not exceed 40% at least until October 7. It also shows that in persimmon leaf cells, ascorbic acid is mainly localized in the cytosol of palisade parenchyma tissue cells where large vacuoles are seen.

Changes in susceptibility of tissues to lipid peroxidation after ingestion of various levels of docosahexaenoic acid and vitamin E

To examine the effects of dietary docosahexaenoic acid (DHA) on the potential changes in endogenous lipid peroxidation in the liver and kidney, diets containing a fixed amount of vitamin E (VE; RRR-alpha-tocopherol equivalent; 134 mg/kg diet) and a graded amount of DHA at the levels of 0, 1.0, 3.4 and 8.7% of total dietary energy were fed to rats for 14 d (Expt 1). In Expt 2, diets containing a fixed amount of DHA (8.7% of total dietary energy) and a graded amount of VE at the levels of 54, 134 and 402 mg/kg were fed to rats for 15 d. In Expt 1 it was found that endogenous lipid peroxide contents of the liver and kidney, as measured by thiobarbituric acid value and chemiluminescence intensity, were higher, and their alpha-tocopherol contents lower than those of the controls, with a gradual increase and decrease in values respectively as the dietary DHA level increased (Expt 1). However, the contents of water-soluble antioxidants, i.e. ascorbic acid and non-protein-SH (glutathione), increased with increases in the dietary DHA level, while the Se-dependent glutathione peroxidase (EC 1.11.1.9) activities did not change or tended to be lower. When the graded level of VE was given to rats in Expt 2, lipid peroxide contents in the liver and kidney did not change significantly in response to the increasing levels of dietary VE, although their alpha-tocopherol contents were higher than control values, increasing with increases in the dietary VE levels. The lipid peroxide scavengers other than alpha-tocopherol changed similarly to those in Expt 1. The results obtained in Expts 1 and 2 indicate that DHA enhances the susceptibility of the liver and kidney to lipid peroxidation concomitant with higher levels of DHA in these tissues, as shown by the fatty acid composition. In addition, VE is unable to protect membranes of the liver and kidney rich in DHA from lipid peroxidation, even after ingestion of the highest level of VE. However, the liver lipid peroxide content of the group given the highest level of DHA was not as high as expected, based on the peroxidizability index which was calculated from the fatty acid composition of the liver lipid.

Human genital melanocytes as androgen target cells

As some parts of human skin - such as genital and areolar skin - become pigmented after puberty, melanocytes in these regions are thought to be sex hormone target cells. We immunohistochemically localized androgen receptors in the nuclei of cultured human genital melanocytes by monoclonal and polyclonal antibodies. When these cells were incubated with [1,2-3H]-testosterone, the major metabolite in the medium was dihydrotestosterone and 5alpha-reduction predominated over 17beta-oxidation. Androgen receptor and type I 5alpha-reductase mRNAs could be detected in genital melanocytes by reverse transcriptase polymerase chain reaction. The tyrosinase activity was stimulated by the addition of androgen. This stimulation was antagonized by cyproterone acetate, whereas tyrosinase mRNA expression was not affected by androgen. These results indicate that human genital melanocytes are androgen target cells, and that androgen plays a role for pigmentation in the specific regional skin after puberty.

Effect of dietary n-3/n-6 fatty acid ratio on the total count, fatty acid composition, and histamine and leukotriene concentrations of mast cells in tunica mucosa bronchiorum of type I allergic guinea pig

To search for the most effective dietary n-3/n-6 ratio to suppress the type I allergic response, we performed basic experiments that applied parameters, associated with the type I allergy. Guinea pigs fed on diets containing lipids with the n-3/n-6 ratio at different levels and the polyunsaturated fatty acid/saturated fatty acid ratio of a fixed level were sensitized with ovalbumin and reared for two weeks. The lowest or critical level of the n-3/n-6 ratio which produced a significant difference in the parameters was as follows: about 2.0 for the response of mast cells and eosinophils; 0.5 and 1.0, respectively, for the uptake of n-3 and n-6 polyunsaturated fatty acids and decreased histamine production; and 0.2 for decreased leukotriene B4 and total leukotrienes 4, and increased leukotrienes 5/leukotrienes 4. The critical level of the n-3/n-6 ratio thus differed widely according to the parameter. Overall, the upper limit for the dietary n-3/n-6 ratio to suppress antigen-induced type I allergic responses is suggested to be around 1.0.

Perineural and neural involvement in skin cancers

BACKGROUND

Malignant skin tumors rarely spread along nerves. Complete resection of involved nerves is often unsuccessful.

OBJECTIVE

In the treatment of tumors with perineural invasion, surgeons should accurately estimate the extent of distant spread.

METHODS

We report six cases of skin cancers, including two basal cell carcinomas, two squamous cell carcinomas, and two neurotropic malignant melanomas, that invaded nerve or perineural spaces.

RESULTS

In three of the cases, the tumors developed on the face and involved the infraorbital nerves or its branches. Two patients suffered from tumors on old burn scars of lower legs. Branches of posttibal nerves were involved in both cases. In the last case, tumor invasion of a branch of the greater occipital nerve was detected.

CONCLUSION

The extent of surgical excision should include the area of skin supplied by the affected nerve, which must be resected in continuity.

Extended V-Y flap: patient reports and reconsideration

The extended V-Y flap, a modified V-Y advancement flap, is very useful in closing relatively large defects on the face. Its extension limb is hinged down as a transposition flap on the end of the V-Y advancement flap to close the most distal portion of the defect. We applied this flap in closing a defect following excision of skin tumors on the face with excellent cosmetic results in 11 patients. However, this flap tended to make a distortion at the base of the flap in the primary closure site. By drawing figures, we concluded that the distortion was due to the characteristic of this technique as a V-Y advancement-rotation flap or V-Y advancement flap with rotation.

Effect of vitamin B12-deficiency on testicular tissue in rats fed by pair-feeding

The effect of vitamin B12 (B12)-deficiency on testicular tissue was investigated through morphological observations of the rats which had been fed on a B12-deficient soybean protein diet by pair-feeding for 100 days. Testicular B12 content was depressed distinctly by the deficiency. Testes weight and their relative weight (weight per 100 g body weight) as well, decreased significantly as compared with those of pair-feeding control rats. Although the decrease in the testicular B12 content due to B12-deficiency was compensated by the administration of cyanocobalamin (CN-B12), alleviation of the decrease in testes weight and relative testes weight was not observed under the condition of the short-term CN-B12 administration. Morphological observations of the testicular tissue in B12-deficient rats revealed atrophy of the seminiferous tubules and aplasia of sperms and spermatids, while testicular findings in both ad libitum-feeding control rats and pair-feeding control rats were normal. There was a tendency for the decrease in seminiferous tubules showing spermatogenesis to be alleviated by administration of CN-B12. The above results indicate that the morphological changes in the testicular tissue are ascribable to B12-deficiency.

Frontonasal flap for reconstruction of complete alar defects

BACKGROUND

It is difficult to reconstruct a satisfactory ala. Axial frontonasal flap has been common in reconstruction of nasal tip. We modified this flap to reconstruct nasal ala.

OBJECTIVE

A modified axial frontonasal flap was applied for reconstruction of complete unilateral alar defects in two patients.

METHODS

Skin from an intact nasal tip covered the alar defect. The resulting defect in the nasal tip was covered with dorsal skin from the nose. Extended mucosa or a hinged nasolabial flap was used to line the mucosal side of the reconstructed ala.

RESULTS

The outcome judged by shape, and texture, was satisfactory. This technique can be employed under field block.

CONCLUSION

The modified frontonasal flap is one of the ideal techniques to reconstruct an entire nasal ala.

Free composite graft for lip reconstruction after tumor excision

This paper represents 10 patients for whom lip defects following excision of malignant tumors were reconstructed by the free composite graft technique using the opposite side of the lip. Usually, for upper lip reconstruction, a switch flap or Zisser-Madden method is commonly used. For lower lip reconstruction, the methods of the double cross-lip flaps or the rotation flap are most frequently used. However, we recommend the free composite graft technique for selective patients, since this method is simpler than the other techniques and the results are excellent both cosmetically and functionally.

Defatting and desalting treatment of indonesian dried-salted fish: dietary effects on alpha-tocopherol and peroxide levels in the serum and liver of rats

The main problem with dried-salted fish (DSF) products is lipid oxidation. PUFA of fish oil is very easily oxidized, and sodium chloride is known to be a pro-oxidant. Many researchers have found that the products of lipid oxidation had negative effects on a variety of species, so we evaluated the effect of a desalting and defatting treatment on the lipid oxidation of Indonesian DSF. The dietary effect of untreated DSF, defatted DSF and desalted DSF on diarrhea, on the internal organs, on hepatic, serum, and urinary lipid peroxidation, and on hepatic and serum alpha-tocopherol were evaluated by using rats. The defatting treatment had a significant effect (p < 0.01) on reducing the lipid oxidation variables of the DSF sample and on protecting the rats from diarrhea. Compared with the rats in the casein group, these in the untreated DSF group had significantly higher values (p < 0.05) for hepatic, serum and urinary lipid peroxidation, but significantly lower values for hepatic and serum alpha-tocopherol. No significant differences were observed between the rats fed with casein and defatted DSF.

Effects of angiotensin I-converting enzyme inhibitory substances derived from Indonesian dried-salted fish on blood pressure of rats

Indonesian dried-salted fish (DSF) was produced from skipjack tuna by soaking the flesh in 15% NaCl (DSF I) or 25% NaCl (DSF II). The DSFs were then hydrolyzed by trypsin, chymotrypsin, Pronase E, and pepsin. Angiotensin I-converting enzyme (ACE) inhibitory activity was measured. The pepsin digest showed the highest inhibitory activity (IC50; 0.63 mg protein/ml). DSF II hydrolysate had higher inhibitory activity than that in DSF I. A three-month storage period of DSF gave higher ACE-inhibitory activity than that of 6 months. An oral administration of pepsin hydrolysate significantly decreased the blood pressure of rats. From the purification steps, at least 4 inhibitor peptides were found. The amino acid sequences of the peptides were Val-Ala-Trp-Lys-Leu, Trp-Ser-Lys-Val-Val-Leu, Ser-Lys-Val-Pro-Pro, and Cys-Trp-Leu-Pro-Val-Tyr, with an IC50 value of 31.97, 156.28, 74.22, and 22.20 microM, respectively.