Stress responses to bacterial and viral mimetics in polycystic ovary syndrome model rats

Polycystic ovary syndrome (PCOS) is associated with an increased risk of psychological distress as well as enhanced responses to psychosocial stress. Recently, it was hypothesized that PCOS patients may be at high risk of novel COVID-19 infections and worse clinical presentations during such infections. Here, we evaluated the effects of PCOS on stress responses to bacterial and viral mimetics using dihydrotestosterone-induced PCOS model rats. Lipopolysaccharide (LPS; a bacterial mimetic) or polyinosinic-polycytidylic acid (Poly-IC; a viral mimetic) was injected into PCOS model rats (PCOS) and non-PCOS rats (control), and the rats' stress responses were evaluated. In the PCOS group, the rats' anorectic and febrile responses to LPS injection were enhanced, whereas their anorectic and febrile responses to Poly-IC injection were unaltered. The PCOS group also exhibited greater changes in peripheral cytokine levels in response to LPS, but not Poly-IC. On the contrary, after the injection of Poly-IC depressed locomotor activity was more evident in the PCOS group, whereas no such changes were observed after LPS injection. These findings indicate that although the stress responses of PCOS model rats to infection may be enhanced, the patterns of change in stress responses and their underlying mechanisms may differ between bacterial and viral infections.

New treatment strategies for uterine sarcoma using secreted frizzled‑related proteins

Secreted frizzled-related proteins (SFRPs) are involved in the development of various types of cancer and function by suppressing the Wnt signaling pathway. To elucidate the clinical implications of SFRPs in uterine sarcoma, SFRP expression levels and their effects on uterine leiomyosarcoma cells were examined. Immunostaining for SFRP4 was performed on uterine smooth muscle, uterine fibroid and uterine leiomyosarcoma tissues. Additionally, the effects of SFRP4 administration on cell viability, migration and adhesion were evaluated in uterine leiomyosarcoma SKN cells using the WST-1 assay (Roche Diagnostics) and the CytoSelect™ 24-well Cell Migration Assay Kit and the CytoSelect™ 48-well Cell Adhesion Assay Kit. The expression levels of SFRP4 in uterine leiomyosarcoma tissues were lower than those in normal smooth muscle and uterine fibroid tissues. In addition, SFRP4 suppressed the viability and migration, and increased the adhesion ability of uterine leiomyosarcoma cells compared with in the control group. In conclusion, SFRP4 may suppress the viability and migration, and enhance the adhesion of sarcoma cells. These results suggested that SFRP4 could be considered as a novel therapeutic target for uterine sarcoma.

Kisspeptin administration may promote precopulatory behavior in male rats independently or supplementally to testosterone and contribute to proceptive behavior in female partners, reducing mating failure

Kisspeptin is a peptide that plays an important role through its effects on the hypothalamus-pituitary-gonadal (HPG) axis. It has also been implicated in sexual behavior. The present study investigated whether the relationship between kisspeptin and sexual behavior is independent of the HPG axis, i.e., testosterone. Sexual behavior was examined after the administration of kisspeptin to gonadally intact male rats and gonadectomized male rats that received testosterone supplementation. Other male rats were also observed for sexual behavior once a week from 2 to 5 weeks after gonadectomy and receiving kisspeptin for the sixth postoperative week. Sexual behavior in female rats serving as the partner for each male was also observed. Female rats were not administered kisspeptin in the present study. The results obtained showed that the administration of kisspeptin increased precopulatory behavior in gonadally intact male rats and gonadectomized male rats that received testosterone supplementation and proceptive behavior in their female partners. Precopulatory behavior in males and receptive behavior in females increased, while copulatory behavior in males and receptive behavior in females remained unchanged. Furthermore, the administration of kisspeptin increased precopulatory behavior in gonadectomized males, but did not affect receptive behavior in females. These results suggest that kisspeptin affected males independently and/or supplementally to testosterone, and also that changes in the presence of testosterone in males had an impact on proceptive behavior in their female partners. In conclusion, kisspeptin may involve an as-yet-unidentified neural pathway in sexual desire independently of the HPG axis.

Oncologic, fertility, and obstetric outcomes with MPA therapy in women with endometrial cancer and atypical endometrial hyperplasia

AIM

Medroxyprogesterone acetate (MPA) is one of the treatments of atypical endometrial hyperplasia (AEH) and endometrial cancer (EC) to preserve the fertility. Efficacy of MPA therapy and fertility and obstetric outcomes after remission were evaluated in EC or AEH patients.

METHODS

Among patients diagnosed with EC or AEH at Tokushima University Hospital between January 2002 and October 2020, we retrospectively analyzed patients, ages range from 26 to 40, who underwent conservative management using MPA (400-600 mg/day).

RESULTS

In total, 19 patients underwent MPA therapy. The 18 (94%) patients achieved complete response (CR), and 1 (5%) patient achieved partial response (PR). Relapse occurred in 6 (32%) patients who had achieved CR. Of the patients who relapsed, 4 patients resumed MPA therapy and were in remission. Among 19 patients, 13 patients attempted pregnancy after CR. All of them underwent ovulation induction or assisted reproductive technology. As a result, 20 pregnancies in 10 (77%) patients and 12 live births in 9 (69%) patients were achieved. Rate of spontaneous abortion was 35% (7/20).

CONCLUSIONS

MPA therapy can produce a high remission rate, and be considered an effective treatment for patients who wish fertility preservation. Around 70% patients who attempt to pregnancy can have at least one baby by infertility treatments. Because recurrence rate after MPA therapy is high, it may be desirable to aim for early pregnancy by active intervention.

Progesterone treatment reduces food intake and body weight in ovariectomized female rats

While the effects of progesterone on body weight and appetite in pre-menopausal conditions have been well elucidated, its effects in post-menopausal conditions have not been clarified. On the contrary, the effects of estrogen on body weight and appetite in post-menopausal conditions have been well established. In this study, the effects of progesterone treatment on body weight, appetite, and fat mass in ovariectomized rats were evaluated. In addition, the central and/or peripheral levels of oxytocin (OT), leptin, and their receptors, which are potent anorectic factors, were examined. Female rats were ovariectomized and divided into control, progesterone-treated, and estrogen-treated groups. Body weight, food intake, and subcutaneous fat mass were lower in both the progesterone and estrogen groups than in the control group. The estrogen group exhibited higher serum OT levels than the control group, whereas the OT levels of the progesterone and control groups did not differ. The serum leptin levels of both the progesterone and estrogen groups were lower than those of the control group. Gene expression analysis of OT, leptin, and their receptors in the hypothalamus and adipose tissue found few significant differences among the groups. Hypothalamic neuropeptide Y (NPY) and pro-opiomelanocortin (POMC) mRNA levels involved in appetite regulation were slightly altered in the progesterone and estrogen groups. These findings suggest that progesterone treatment may have favorable effects on body weight, appetite, and fat mass regulation in post-menopausal conditions and that the mechanisms underlying these effects of progesterone differ from those underlying the effects of estrogen.

Developmental Changes in Hypothalamic and Serum Oxytocin Levels in Prenatally Normally Nourished and Undernourished Rats

Changes in the activities of some metabolic factors have been suggested to increase the risk of conditions associated with the Developmental Origins of Health and Disease (DOHaD). We examined changes in oxytocin (OT), a metabolic factor, and OT receptor (OTR) mRNA levels throughout the developmental period in rats of intrauterine undernutrition. Pregnant rats were divided into two groups: a maternal normal nutrition (mNN) and maternal undernutrition (mUN) group. Serum OT concentrations and hypothalamic mRNA levels of OT and OTR were measured in both offspring at various postnatal stages. Both offspring showed significant increases in serum OT concentrations during the neonatal period, significant reductions around the pubertal period, and significant increases in adulthood. Hypothalamic OT mRNA expression levels gradually increased from the neonatal to pubertal period and decreased in adulthood in both offspring. In the pre-weaning period, hypothalamic OT mRNA expression levels were significantly lower in the mUN offspring than in the mNN offspring. In the mUN offspring, hypothalamic OTR mRNA expression levels transiently increased during the neonatal period, decreased around the pubertal period, and increased again in adulthood, whereas transient changes were not detected in mNN offspring. These changes could affect nutritional and metabolic regulation systems in later life and play a role in the mechanisms underlying DOHaD.

Obstructed hemivagina and ipsilateral renal agenesis (OHVIRA) syndrome: A case report

INTRODUCTION

Obstructed hemivagina and ipsilateral renal agenesis (OHVIRA) is a rare urogenital malformation. The clinical symptoms of OHVIRA include uterine morphology abnormality, persistent vaginal discharge, and renal anomaly or agenesis. Delayed diagnosis can lead to complications, such as pelvic inflammatory disease, adhesion to the oviduct, and endometriosis.

PRESENTATION OF CASE

We report the case of a 12-year-old girl who presented with severe dysmenorrhea and abnormal vaginal discharge. The patient was diagnosed with OHVIRA based on magnetic resonance imaging findings. The patient underwent combined transvaginal and laparoscopic surgery for drainage of hematocolpos and adhesiolysis of the pelvic cavity. The patient had an uncomplicated recovery and normal menstrual cycle after surgery.

DISCUSSION

OHVIRA is a rare syndrome, of which delayed diagnosis may result in the development of endometriosis.

CONCLUSION

We report that a combined laparoscopic and transvaginal approach was useful for treating OHVIRA with oviductal hematoma.

New discoveries on the interaction between testosterone and oxytocin in male rats - Testosterone-mediated effects of oxytocin in the prevention of obesity

Sex steroid hormones are important for the maintenance of metabolism in both sexes. Oxytocin (OT) is a neuropeptide that is synthesized in hypothalamic regions, secreted from the posterior lobe of the pituitary gland, and is involved in the control of appetite, body weight, and metabolism. Estrogen and OT both play a role in the metabolism of nutrients, and OT has potential in the prevention of obesity. However, the relationship between testosterone and OT remains unclear. Therefore, the present study investigated the relationship between testosterone and OT in hypogonadal male rats and male rats receiving testosterone replacement therapy. The results obtained showed that testosterone increased serum OT levels and promoted the secretion of adiponectin from visceral fat, and reduced body fat directly and/or indirectly through OT and adiponectin. Testosterone also increased the expression of OT receptors in the hypothalamus to increase sensitivity to OT, and perhaps because of this, OT administration had the effect of reducing food intake and body weight gain in both normal and castrated rats, and this effect was stronger in normal rats. In other words, the preventative effects of OT on obesity may be synergistic with testosterone. Collectively, the present results indicate that testosterone exerts indirect effects to prevent obesity and atherosclerosis through OT and adiponectin. In conclusion, testosterone replacement therapy is useful for preventing obesity caused by hypogonadism, and OT has potential in supportive medicine to prevent obesity and adult diseases.

Effects of undernutrition and low energy availability on reproductive functions and their underlying neuroendocrine mechanisms

It has been well established that undernutrition and low energy availability disturb female reproductive functions in humans and many animal species. These reproductive dysfunctions are mainly caused by alterations of some hypothalamic factors, and consequent reduction of gonadotrophin-releasing hormone (GnRH) secretion. Evidence from literature suggests that increased activity of orexigenic factors and decreased activity of anorexigenic/satiety-related factors in undernourished conditions attenuate GnRH secretion in an integrated manner. Likewise, the activity of kisspeptin neurons, which is a potent stimulator of GnRH, is also reduced in undernourished conditions. In addition, it has been suggested that gonadotrophin-inhibitory hormone, which has anti-GnRH and gonadotrophic effects, may be involved in reproductive dysfunctions under several kinds of stress conditions. It should be remembered that these alterations, i.e., promotion of feeding behavior and temporary suppression of reproductive functions, are induced to prioritize the survival of individual over that of species, and that improvements in metabolic and nutritional conditions should be considered with the highest priority.

Biotin levels in blood and follicular fluid and their associations with pregnancy outcomes in IVF/ICSI patients

It has been shown that biotin, a water-soluble vitamin (B7), plays roles in reproductive functions, such as oocyte maturation and embryo development, in experimental animals. On the other hand, little is known about the clinical effects of biotin on human reproduction. In this study, serum and follicular fluid biotin levels were measured in patients who underwent in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI), and their associations with reproductive outcomes were evaluated. As a result, biotin was detected in follicular fluid, as well as serum, and the biotin levels of follicular fluid were found to be positively correlated with those of serum. The biotin levels of serum were higher than those of follicular fluid, suggesting that biotin may be taken up into the follicular fluid from the blood. Although serum and follicular fluid biotin levels tended to be higher in pregnant patients than in non-pregnant patients, these data did not show the significant statistical difference. These findings indicate that biotin does not contribute to the maintenance of oocyte quality, and hence, it does not increase fertilization and pregnancy rates. J. Med. Invest. 69 : 65-69, February, 2022.

Diabetes autoantibodies do not predict progression to diabetes in adults: the Diabetes Prevention Program

AIMS

To determine if the presence of diabetes autoantibodies predicts the development of diabetes among participants in the Diabetes Prevention Program.

METHODS

A total of 3050 participants were randomized into three treatment groups: intensive lifestyle intervention, metformin and placebo. Glutamic acid decarboxylase (GAD) 65 autoantibodies and insulinoma-associated-2 autoantibodies were measured at baseline and participants were followed for 3.2 years for the development of diabetes.

RESULTS

The overall prevalence of GAD autoantibodies was 4.0%, and it varied across racial/ethnic groups from 2.4% among Asian-Pacific Islanders to 7.0% among non-Hispanic black people. There were no significant differences in BMI or metabolic variables (glucose, insulin, HbA(1c), estimated insulin resistance, corrected insulin response) stratified by baseline GAD antibody status. GAD autoantibody positivity did not predict diabetes overall (adjusted hazard ratio 0.98; 95% CI 0.56-1.73) or in any of the three treatment groups. Insulinoma-associated-2 autoantibodies were positive in only one participant (0.033%).

CONCLUSIONS

These data suggest that 'diabetes autoimmunity', as reflected by GAD antibodies and insulinoma-associated-2 autoantibodies, in middle-aged individuals at risk for diabetes is not a clinically relevant risk factor for progression to diabetes.

Lifestyle and metformin treatment favorably influence lipoprotein subfraction distribution in the Diabetes Prevention Program

CONTEXT

Although intensive lifestyle change (ILS) and metformin reduce diabetes incidence in subjects with impaired glucose tolerance (IGT), their effects on lipoprotein subfractions have not been studied.

OBJECTIVE

The objective of the study was to characterize the effects of ILS and metformin vs placebo interventions on lipoprotein subfractions in the Diabetes Prevention Program.

DESIGN

This was a randomized clinical trial, testing the effects of ILS, metformin, and placebo on diabetes development in subjects with IGT.

PARTICIPANTS

Selected individuals with IGT randomized in the Diabetes Prevention Program participated in the study.

INTERVENTIONS

Interventions included randomization to metformin 850 mg or placebo twice daily or ILS aimed at a 7% weight loss using a low-fat diet with increased physical activity.

MAIN OUTCOME MEASURES

Lipoprotein subfraction size, density, and concentration measured by magnetic resonance and density gradient ultracentrifugation at baseline and 1 year were measured.

RESULTS

ILS decreased large and buoyant very low-density lipoprotein, small and dense low-density lipoprotein (LDL), and small high-density lipoprotein (HDL) and raised large HDL. Metformin modestly reduced small and dense LDL and raised small and large HDL. Change in insulin resistance largely accounted for the intervention-associated decreases in large very low-density lipoprotein, whereas changes in body mass index (BMI) and adiponectin were strongly associated with changes in LDL. Baseline and a change in adiponectin were related to change in large HDL, and BMI change associated with small HDL change. The effect of metformin to increase small HDL was independent of adiponectin, BMI, and insulin resistance.

CONCLUSION

ILS and metformin treatment have favorable effects on lipoprotein subfractions that are primarily mediated by intervention-related changes in insulin resistance, BMI, and adiponectin. Interventions that slow the development of diabetes may also retard the progression of atherosclerosis.

Synthesis and biological activity of N-acylphenothiazines

Previous studies have demonstrated the relationship between radical intensity and cytotoxic activity in water-soluble compounds. This relationship was investigated in lipophilic compounds. Several N-acylphenothiazines showed higher cytotoxic activity against human leukemic and squamous carcinoma cell lines than phenothiazine, the parent compound. Electron spin resonance (ESR) spectroscopy showed that these active compounds produced much lower amounts of radicals than phenothiazine. Several compounds failed to inhibit the cytopathic effects of human immunodeficiency virus (HIV) infection in MT-4 cells. It suggested that the radical-mediated-mechanisms has not involved in the induction of cytotoxic activity by lipophilic compounds, such as N-acylphenothiazines.

Antiviral properties of a mangrove plant, Rhizophora apiculata Blume, against human immunodeficiency virus

A polysaccharide extracted from the leaf of Rhizophora apiculata (RAP) was assessed in cell culture systems, for its activity against human and simian immunodeficiency viruses. RAP inhibited HIV-1 or HIV-2 or SIV strains in various cell cultures and assay systems. It blocked the expression of HIV-1 antigen in MT-4 cells and abolished the production of HIV-1 p24 antigen in peripheral blood mononuclear cells (PBMC); the 50% effective concentration (EC50) of RAP in HIV-1 infected MT-4 cells and in PBMC was 10.7 and 25.9 microg/ml, respectively. RAP (100 microg/ml) completely blocked the binding of HIV-1 virions to MT-4 cells. RAP also reduced the production of viral mRNA when added before virus adsorption. RAP inhibited syncytium formation in cocultures of MOLT-4 cells and MOLT-4/HIV-1(IIIB) cells. RAP did not prolong activated partial thromboplastin time (APTT) up to 500 microg/ml. These properties may be advantageous should RAP be considered for further development.

Inhibition of M-tropic HIV-1 infection by the fd phage-gene 3 protein with MIP-1alpha-binding activity

CCR5 is a chemokine receptor with seven transmembrane-domains. It is expressed on T cells and macrophages and functions as the principal co-receptor for macrophage (M)-tropic strains of HIV-1. The anti-CCR5 monoclonal antibody (mAb) 2D7 inhibits the binding and chemotaxis of the three natural beta-chemokine ligands of CCR5, macrophage inflammatory protein (MIP)-1alpha, MIP-1beta, and RANTES, to CCR5(+) cells. The mAb also efficiently blocks the infectivity of several M-tropic and dual-tropic HIV-1 strains in vitro. In this study, we attempted to determine the peptide motif recognized with the 2D7 mAb. We isolated phage clones by panning a phage display library using 2D7 and identified three peptide motifs. One of these phage clones (M23) showed a marked inhibitory activity on HIV-1 infection. The unique sequence of 15 amino acids with an internal disulfide bond was inserted in the g3p of the M23 phage clone (M23-g3p). The M23-g3p was purified by fast-performance liquid chromatography (FPLC). We show here that (1) M23-g3p was specifically recognized with anti-CCR5 mAb; (2) M23-g3p showed inhibitory activity on the infectivity of M-tropic but not T-tropic HIV-1 strains; (3) M23-g3p bound to MIP-1alpha, MIP-1beta, and RANTES but not MCP-1. These results suggested that the M23-g3p might mimic the CCR5-binding domain shared by beta-chemokines, MIP-1alpha, MIP-1beta, and RANTES as well as the HIV-1 infection.

The in vitro synthesized and processed human insulin receptor precursor binds insulin

The cell-free examination of the human insulin receptor during biogenesis may provide a greater understanding of the elements that contribute to the acquisition of receptor function. The insulin receptor precursor components were produced in a cell-free system and the insulin binding ability of the [35S]methionine-labeled translation products was determined. The processed proreceptor represented by a 190 kDa band was retained on insulin-linked biotin-streptavidin agarose or an insulin column. The insulin binding 190 kDa band migrated slower than the non-binding 190 kDa band on SDS-PAGE which suggests that covalent modifications account for these differences. The trypsin-digested product of the 190 kDa proreceptor was also retained on insulin-linked biotin-streptavidin agarose, however the alpha-subunit precursor was retained on insulin agarose to a much lesser degree. We conclude that a significant fraction of the processed, in vitro translated insulin proreceptor acquires insulin binding ability.

Fasting hyperinsulinemia and increased waist-to-hip ratios in non-wasting individuals with AIDS

OBJECTIVE

To identify metabolic and body composition changes associated with HIV-1 infection in a cross-sectional study of individuals stratified by immunologic status and body mass.

DESIGN

Metabolic abnormalities including glucose intolerance and changes in body morphology have recently been described in HIV-1-infected individuals following therapy with protease inhibitor-containing highly active anti-retroviral therapy. Although this is suggestive of a direct drug effect, the possibility that HIV infection may induce a tendency towards such underlying derangements should be considered. HIV-infected patients are heterogeneous with respect to immunologic status and body mass. In examining the underlying effect of HIV-1 on metabolic and body composition parameters, stratification by various immunologic and body mass categories may give divergent results that would not be detected otherwise.

METHODS

Thirty male participants were categorized into four cohorts: non-wasting HIV-seronegative controls, non-wasting HIV-infected patients with relatively intact immune function (CD4 cell count > 500 x 10(6)/l); non-wasting individuals with AIDS (CD4 cell count < 200 x 10(6)/l); and individuals with AIDS wasting.

RESULTS

Increased fasting plasma insulin and waist-to-hip ratios were found specifically in non-wasting individuals with AIDS compared with HIV-negative controls.

CONCLUSIONS

Our study emphasises the importance of both body mass and immune function in studying metabolic and body composition abnormalities associated with HIV-1 infection. The association of increased waist-to-hip ratios and hyperinsulinemia suggestive of insulin resistance in non-wasting individuals with AIDS suggest that the tendency towards these metabolic abnormalities may be related to the HIV infectious process or to factors associated with immunologic dysfunction.

Involvement of oxidative stress in tumor cytotoxic activity of hepatocyte growth factor/scatter factor

In this study, we show that N-acetylcysteine (NAC), a precursor of glutathione and an intracellular free radical scavenger, almost completely prevented hepatocyte growth factor (HGF)-suppressed growth of Sarcoma 180 and Meth A cells, and HGF-induced apoptosis, assessed by DNA fragmentation, and increase in caspase-3 activity, in Sarcoma 180 cells. The reduced form of glutathione also prevented HGF-suppressed growth of the cells as effective as NAC. Ascorbic acid partially prevented the effect of HGF, but other antioxidants such as superoxide dismutase, catalase, and vitamin E, and the free radical spin traps N-t-butyl-alpha-phenylnitrone and 3,3,5, 5-tetramethyl-1-pyrroline-1-oxide did not have protective effects. HGF caused morphological changes of the cells, many cells showing condensation and rounding, and enhanced the generation of intracellular reactive oxygen species (ROS) as judged by flow cytometric analysis using 2',7'-dichlorofluorescein diacetate. NAC completely prevented both HGF-induced morphological changes and the enhancement of ROS generation in the cells. However, NAC did not prevent the HGF-induced scattering of Madin-Darby canine kidney cells. To our knowledge, this is the first report that HGF stimulates the production of ROS, and our results suggest the involvement of oxidative stress in the mechanism by which HGF induces growth suppression of tumor cells.

Down-regulation of CXCR4 by human herpesvirus 6 (HHV-6) and HHV-7

Recent studies have demonstrated that human herpesvirus 6 (HHV-6) and HHV-7 interact with HIV-1 and alter the expression of various surface molecules and functions of T lymphocytes. The present study was undertaken to clarify whether coreceptors for HIV-1, CXCR4 and CCR5, are necessary for HHV-6 and HHV-7 infection. Although CXCR4 and CCR5 appeared not to be the coreceptors for these viruses, marked down-regulation of CXCR4, but not CCR5, was detected in HHV-6 variant A (HHV-6A)-, HHV-6 variant B (HHV-6B)-, and HHV-7-infected cells. Down-regulation of CXCR4 resulted in impairment of chemotaxis and a decreased level of elevation of the intracellular Ca2+ concentration in response to stromal cell-derived factor-1. Northern blot analysis of mRNAs extracted from HHV-6A-, HHV-6B-, and HHV-7-infected CD4+ T lymphocytes demonstrated a markedly decreased level of CXCR4 gene transcription, but the posttranscriptional stability of CXCR4 mRNA was not significantly altered. These data demonstrate that unlike HIV-1, HHV-6 and HHV-7 infections do not require expression of CXCR4 or CCR5, whereas marked down-regulation of CXCR4 is induced by these viruses, suggesting that HHV-6 and HHV-7 infections may render CD4+ T lymphocytes resistant to T lymphocyte-tropic HIV-1 infection.

Lipoteichoic acid acts as an antagonist and an agonist of lipopolysaccharide on human gingival fibroblasts and monocytes in a CD14-dependent manner

CD14 has been implicated as a receptor of lipoteichoic acid (LTA) and other bacterial components as well as lipopolysaccharide (LPS). Since the structures of LTAs from various gram-positive bacteria are heterogeneous, we analyzed the effects of LTAs on the secretion of interleukin-8 (IL-8) by high- and low-CD14-expressing (CD14(high) and CD14(low)) human gingival fibroblasts (HGF). While Bacillus subtilis LTA had an IL-8-inducing effect on CD14(high) HGF which was considerably weaker than that of LPS, Streptococcus sanguis and Streptococcus mutans LTAs had practically no effect on the cells. B. subtilis LTA had only a weak effect on CD14(low) HGF, as did LPS. S. sanguis and S. mutans LTAs at a 1,000-fold excess each completely inhibited the IL-8-inducing activities of both LPS and a synthetic lipid A on CD14(high) HGF. The effect of LPS was also inhibited by the presence of an LPS antagonist, synthetic lipid A precursor IVA (LA-14-PP), with a 100-fold higher potency than S. sanguis and S. mutans LTAs and by anti-CD14 monoclonal antibody (MAb). S. sanguis and S. mutans LTAs, LA-14-PP, and anti-CD14 MAb had no significant effect on phorbol myristate acetate-stimulated IL-8 secretion by HGF. These LTAs also inhibited the IL-8-inducing activity of B. subtilis LTA on CD14(high) HGF, as did LA-14-PP and anti-CD14 MAb. The antagonistic and agonistic functions of LTAs were also observed with human monocytes. Binding of fluorolabeled LPS to human monocytes was inhibited by S. sanguis LTA, although the inhibition was 100 times weaker than that of LPS itself, and anti-CD14 MAb inhibited fluorolabeled LPS and S. sanguis LTA binding. Binding of LTAs to CD14 was also observed with nondenaturing polyacrylamide gel electrophoresis. These results indicate that LTAs act as antagonists or agonists via a CD14-dependent mechanism, probably due to the heterogeneous structure of LTAs, and that an antagonistic LTA might be a useful agent for suppressing the periodontal disease caused by gram-negative bacteria.

Marked increase in anti-HIV activity, as well as inhibitory activity against HIV entry mediated by CXCR4, linked to enhancement of the binding ability of tachyplesin analogs to CXCR4

T22 ([Tyr5,12, Lys7]-polyphemusin II) is a strong anti-HIV compound. Six analogs of T22 and two natural forms were synthesized. Of them, all downsized peptides (14 residues; TW70, T131, T134, and T140) showed a higher selectivity index than did other, 17- or 18-residue peptides. In particular, T134 and T140 showed both lower cytotoxicity and higher antiviral activity than did T22 against HIV infection of MT-4 cells, an HTLV-I-bearing T cell line. To clarify the inhibitory mode of T22 and its analogs, we used a single-round replication assay (luciferase assay), in which different envelope-bearing pseudotypes were used to infect CXCR4- or CCR5-bearing U87 cells via CD4. All of the analogs inhibited T cell line-tropic strain HXB-2 (X4) and dual-tropic strain 89.6 (R5X4) HIV infections mediated by CXCR4, but had no effect on macrophage-tropic strain ADA (R5) or 89.6 HIV infections mediated by CCR5. The inhibition by T134 (IC50 of 2.70 nM) and T140 (IC50 of 0.432 nM) was also stronger than that by T22 (IC50 of 5.05 nM). The binding of anti-CXCR4 monoclonal antibody 12G5 to lymphoma-derived T cell line Sup-T1 was more efficiently blocked by T134 and T140 than by T22. Taken together, T22 and its analogs T134 and T140 exerted their inhibition by specific binding to CXCR4. The marked increase in the anti-HIV activity of T134 and T140 was ascribed to an enhancement in their ability to bind to CXCR4.

Relationship between radical intensity and biological activity of cacao husk extracts

The relationship between radical intensity and biological activity of cacao husk extracts was investigated. Electron spin resonance (ESR) spectroscopy demonstrated that the radical intensity of hexane, acetone, methanol and 70% methanol extracts increased with water-solubility. Several fractions of these husk extracts, separated by different column chromatographies, significantly inhibited the cytopathic effect of human immunodeficiency virus (HIV) infection in parallel with their radical intensity. However, their cytotoxic activity against human leukemic and carcinoma cell lines is not always correlated with their radical intensity. Water-soluble and lipophilic compounds might induce cytotoxic activity by different mechanisms.

T134, a small-molecule CXCR4 inhibitor, has no cross-drug resistance with AMD3100, a CXCR4 antagonist with a different structure

T22, an analog of polyphemusin II (18 amino acid residues), was found to block T-tropic human immunodeficiency virus type 1 (HIV-1) entry into target cells as a CXCR4 inhibitor. We synthesized T134, a small analog (14 amino acid residues) of T22 with reduced positive charges. T134 exhibited highly potent activity and significantly less cytotoxicity in comparison to that of T22. T134 prevents the anti-CXCR4 monoclonal antibody from binding to peripheral blood mononuclear cells but has no effect on the binding of anti-CCR5 monoclonal antibodies. Since T134 inhibits the binding of stromal cell-derived factor-1 (SDF-1) to MT-4 cells, it seems that T134 prevents HIV-1 entry by binding to CXCR4. The bicyclam AMD3100 has also been shown to block HIV-1 entry via CXCR4 but not via CCR5. Both T134 and AMD3100 are CXCR4 antagonists and low-molecular-weight compounds but have different structures. Our results indicate that T134 is active against wild-type T-tropic HIV-1 strains and against AMD3100-resistant strains.

Radical modulation activity of pine cone extracts of Pinus elliottii var. Elliottii

The radical modulation activity of lignins prepared from the cone of Pinus elliottii var. Elliottii was investigated, using ESR spectroscopy. These lignins produced radical(s) under alkaline conditions, and the radical intensity was increased with increasing pH. Lower concentrations of lignins slightly reduced the radical intensity of sodium ascorbate, whereas higher concentrations of lignins enhanced both the radical intensity and cytotoxic activity of sodium ascorbate. Lignins effectively scavenged superoxide anion, produced by hypoxanthine-xanthine oxidase reaction. Elliottii lignins significantly inhibited the human immunodeficiency virus (HIV)-induced cytopathic effect, in similar fashions to other natural, commercial and synthetic lignins. Pretreatment of mice with lignins significantly protected them from the lethal infection with E. coli. Crude alkaline extracts of Elliottii pine cone displayed similar magnitude of activity with lignins. These data further supports the medicinal efficacy of plant extracts.

A low-molecular-weight inhibitor against the chemokine receptor CXCR4: a strong anti-HIV peptide T140

T22 ([Tyr5,12, Lys7]-polyphemusin II) is an 18-residue peptide amide, which has strong anti-HIV activity. T22 inhibits the T cell line-tropic (T-tropic) HIV-1 infection through its specific binding to a chemokine receptor CXCR4, which serves as a coreceptor for the entry of T-tropic HIV-1 strains. Herein, we report our finding of novel 14-residue CXCR4 inhibitors, T134 and T140, on the basis of the T22 structure. In the assays we examined, T140 showed the highest inhibitory activity against HIV-1 entry and the strongest inhibitory effect on the binding of an anti-CXCR4 monoclonal antibody (12G5) to CXCR4 among all the CXCR4 inhibitors that have been reported up to now.

A lipoteichoic acid fraction of Enterococcus hirae activates cultured human monocytic cells via a CD14-independent pathway to promote cytokine production, and the activity is inhibited by serum components

To elucidate the cellular activation mechanisms of lipoteichoic acid (LTA) compared with those of lipopolysaccharide (LPS), a quantitatively major LTA fraction, QM-1M, was prepared from hot phenol-water extracts of Enterococcus hirae (ATCC 9790) by hydrophobic octyl-Sepharose chromatography and by ion-exchange membrane (QMA-Mem Sep 1010) chromatography as a 60% 1-propanol- and 1 M NaCl-eluted fraction. Unlike the reference Escherichia coli LPS, QM-1M did not demonstrate any ability to induce cytokines in a human whole blood culture system in this study, whereas QM-1M induced a few cytokines such as interleukin (IL)-8 and tumor necrosis factor-alpha in human monocytic THP-1 cell and human peripheral mononuclear cell (PBMC) cultures in the absence of serum. Fetal calf and human sera decreased the above cytokine induction by QM-1M in THP-1 and PBMC cultures, whereas sera increased activities of the reference LPS. IL-8 induction in the absence of serum in response to QM-1M was demonstrated to proceed through a CD14-independent pathway unlike the reference LPS.

3-(5-Dimethylamino-1-naphthalenesulphonyl)-2-(3-pyridyl)thiazolidine (YHI-1) selectively inhibits human immunodeficiency virus type 1

3-(5-Dimethylamino-1-naphthalenesulphonyl)-2-(3-pyridyl)thiazolidi ne (YHI-1), a synthetic analogue of D-cysteinolic acid isolated from sardines (Sardinops melanostictus), was found to be a specific inhibitor of human immunodeficiency virus type 1 (HIV-1) replication in various cell cultures. YHI-1 inhibited HIV-1IIIB replication with a 50% effective concentration (EC50) of 3.35, 10.23 and 4.61 microM in MT-4 cells, peripheral blood mononuclear cells and MAGI-CCR5 cells, respectively. However, no antiviral activity was observed with non-nucleoside reverse transcriptase inhibitor (NNRTI)-resistant HIV-1 strains, such as nevirapine-resistant HIV-1HE/NEV and MKC-442-resistant HIV-1IIIB-R, or with HIV-2ROD or SIVMAC. YHI-1 failed to inhibit reverse transcriptase (RT) activity in vitro with different template-primer systems. Time-of-addition experiments, the failure to inhibit NNRTI-resistant strains and the failure to show in vitro activity against RT suggest that a metabolite of YHI-1 inside the cell acts like an NNRTI. Thus, YHI-1 seems to belong to a new class of HIV-1 inhibitor and is a good candidate for further development.

Pharmacophore identification of a chemokine receptor (CXCR4) antagonist, T22 ([Tyr(5,12),Lys7]-polyphemusin II), which specifically blocks T cell-line-tropic HIV-1 infection

We have previously found that T22 ([Tyr(5,12), Lys7]-polyphemusin II) has strong anti-human immunodeficiency virus (HIV) activity, and that T22 inhibits T cell-line-tropic HIV-1 infection mediated by CXCR4/fusin. T22 is an 18-residue peptide amide, which takes an antiparallel beta-sheet structure that is maintained by two disulfide bridges. Structure-activity relationship (SAR) studies on T22 have disclosed the contributions of each region of T22 to activity or cytotoxicity, and have provided the following useful information to develop new CXCR4 antagonists: The number of Arg residues in the N-terminal and C-terminal regions of T22 is closely related to anti-HIV activity. Addition of a variety of functional groups at the N-terminal end results in increases in activity. Disulfide rings, especially the major disulfide loop, are indispensable for anti-HIV activity and maintenance of the beta-sheet structure. Trp3 can be replaced by other aromatic residues (Tyr, Phe and L-2-naphthylalanine). Between two repeats of Tyr-Arg-Lys, which are a characteristic structure in T22, Tyr-Arg-Lys in the N-terminal portion is more closely associated with anti-HIV activity and maintenance of the beta-sheet structure. A positive charge in the side chain at the (i + 1) position of the beta-turn region is necessary for strong activity. Through these studies, we have found several compounds having higher selectivity indexes (50% cytotoxic concentration/50% effective concentration) than that of T22.

Radical modulation activity of lignins from a mangrove plant, Ceriops decandra (Griff.) Ding Hou

The radical modulation activity of hot water and alkaline extracts from leaf of Ceriops decandra, a mangrove plant, was investigated using ESR spectroscopy. IR and NMR analyses demonstrate that the leaf extracts have a lignin-like polyphenolic structure. All these extracts produced radical(s) under alkaline conditions. The radical intensity of sodium ascorbate was slightly reduced at lower concentrations of the extracts, but it was synergistically enhanced at higher concentrations. All the extracts effectively scavenged superoxide anion, produced by hypoxanthine-xanthine oxidase reaction. Pretreatment of mice with the extracts significantly protected them from the lethal infection by E. coli. Similar activity was found in lignins from pine seed shell of Pinus parviflora Sieb. et Zucc. These data further support the medicinal efficacy of plant extracts.

Hyperinsulinemia and cardiovascular disease in elderly men: the Honolulu Heart Program

Hyperinsulinemia has been associated with cardiovascular disease (CVD), but whether this relation is independent of other CVD risk factors is uncertain. Most studies have focused on coronary heart disease (CHD), but few have included peripheral vascular disease (PVD) and stroke. Moreover, evidence in elderly and minority populations is limited. Between 1991 and 1993, 3562 elderly (71 to 93 years) Japanese-American men from the Honolulu Heart Program were examined and had fasting insulin levels measured. Hyperinsulinemia, defined as a fasting insulin > or =95th percentile among nonobese men with normal glucose tolerance and no diabetic history or medication use, was observed in 22% of the population. Subjects with hyperinsulinemia had a more adverse CVD risk factor profile and had higher age-adjusted prevalences of CHD, angina, PVD, thromboembolic stroke, and hemorrhagic stroke compared with those without hyperinsulinemia. Age-adjusted fasting insulin levels but not 2-hour levels were also significantly elevated (P<.01) in those with prevalent CVD compared with those without. In logistic regression analyses, adjustment for multiple CVD risk factors attenuated the relations of hyperinsulinemia with CHD, angina, and PVD to nonsignificant levels, whereas those involving thromboembolic and hemorrhagic stroke were strengthened and remained significant (odds ratios=2.27 and 7.53, 95% confidence intervals=1.25 to 4.13 and 1.65 to 34.25, respectively). When multivariate analyses were restricted to nondiabetic subjects, associations were slightly weaker and in general nonsignificant. Nondiabetic men with thromboembolic stroke were twice as likely to have hyperinsulinemia as those who were stroke-free, although this association was of borderline significance (odds ratio= 1.99, 95% confidence interval=0.95 to 4.17, P=.069). In subjects with elevated total cholesterol levels, somewhat stronger associations were observed for PVD and stroke but not for CHD. Although further prospective studies are indicated, particularly for PVD and stroke, these cross-sectional results are consistent with an indirect role for insulin in CVD, wherein hyperinsulinemia or an underlying insulin-resistant state may adversely affect other CVD risk factors or serve as a marker for an atherogenic or thrombogenic state.

Association of insulin levels with lipids and lipoproteins in elderly Japanese-American men

PURPOSE

Elevated insulin levels have been associated with cardiovascular disease, but the relationship of insulin with other risk factors and its position in the atherosclerotic pathway is uncertain. A cross-sectional study was conducted to determine whether insulin concentrations were associated with lipids and lipoproteins independently of adiposity and other cardiovascular risk factors.

METHODS

Subjects included 3417 Japanese-American men from the Honolulu Heart Program who completed a follow-up examination between 1991 and 1993 and were 71-93 years of age. Men were categorized by quintiles of fasting and 2-hour insulin concentration.

RESULTS

Age-adjusted mean high-density lipoprotein (HDL) cholesterol and triglyceride levels varied significantly across quintiles of fasting and 2-hour insulin (P < 0.001, tests for trend), but insulin was not related to total cholesterol and low-density lipoprotein (LDL) cholesterol. HDL cholesterol decreased from 59.3 to 43.7 mg/dL and triglycerides increased from 95.6 to 175.8 mg/dL comparing lowest to highest quintiles of fasting insulin, respectively. These associations were slightly stronger in lean than obese subjects and in nondiabetic versus diabetic individuals particularly for 2-hour insulin levels. Multiple linear regression analysis adjusting for several adiposity measures separately (body mass index (BMI), subscapular skinfold thickness, waist circumference, and waist/hip ratio) and other cardiovascular risk factors attenuated associations slightly but they still remained statistically significant. Estimated differences in HDL cholesterol across extreme quintiles of fasting insulin were reduced slightly from 15.6 mg/dL with adjustment for age to 12.5 mg/dL with adjustment for age and BMI, and to 11.3 mg/dL with adjustment for age, BMI, and cardiovascular risk factors.

CONCLUSIONS

Insulin concentration was strongly and independently associated with HDL cholesterol and triglycerides in this cohort of elderly Japanese-American men. Since this study was cross-sectional, further investigation is required to determine whether elevated insulin levels are causally related to dyslipidemia.

Effective lowly cytotoxic analogs of an HIV-cell fusion inhibitor, T22 ([Tyr5,12, Lys7]-polyphemusin II)

A tachyplesin peptide analog, T22 ([Tyr5,12, Lys7]-polyphemusin II), and its shortened congener, TW70 (des-[Cys8,13, Tyr9,12]-[D-Lys10, Pro11]-T22) have strong anti-human immunodeficiency virus (HIV) activity, comparable to that of 3'-azido-2', 3'-dideoxythymidine (AZT). T22 and TW70 are extremely basic peptides, containing 5 Arg residues and 3 Lys residues. The number of positive charges might be related in part to high collateral cytotoxicities of T22 and TW70. Here we have synthesized several analogs, in which the number of positive charges has been reduced through amino acid substitutions using Glu or L-citrulline. As a result, several effective compounds have been found which possess higher selectivity indexes (SIs, 50% cytotoxic concentration/50% effective concentration) than those of T22 and TW70. Higher SIs were attributed mainly to a decrease in cytotoxicity.

Distribution pattern of HNF-3beta proteins in developing embryos of two mammalian species, the house shrew and the mouse

The pattern of expression of HNF-3beta in organizing centers and axial structures during early vertebrate development suggests an important role for this protein in the establishment of the vertebrate body plan. To establish whether the pattern of expression during embryogenesis is species specific, a comparative immunohistochemical study of two mammalian species, the house shrew, insectivore, and the mouse was carried out; it is difficult to obtain accurate morphological differences from the study of remotely related animals. The earliest expression of HNF-3beta appeared in the node and hypoblast (or endoderm) in both species, where the presumptive foregut endoderm showed intense immunoreactivity prior to the formation of the axial mesoderm, suggesting a role different from that in axial formation. The anterior extension of immunopositive axial mesoderm and the median band of the neural plate varied between the two species, and was delayed in the house shrew. HNF-3beta in the anterior end of the foregut disappeared transiently in the house shrew but persisted in the mouse embryo. An asymmetric pattern of distribution in the primitive streak was also observed in the mouse but not in the house shrew. The present immunohistochemical study elucidated that the distribution of HNF-3beta is conserved initially but soon manifests species specificities in development even between mammalian species.

A novel component different from endotoxin extracted from Prevotella intermedia ATCC 25611 activates lymphoid cells from C3H/HeJ mice and gingival fibroblasts from humans

A novel immunobiologically active fraction was prepared from a phenol-water extract of Prevotella intermedia ATCC 25611 by Sephadex G-100 column chromatography. The fraction consisted mainly of carbohydrate and protein and was devoid of fatty acid. The fraction showed high-molecular-weight bands (10,000 to 12,000) on deoxycholate polyacrylamide gel electrophoresis (DOC-PAGE) and was scarcely active in a Limulus test. We designated the fraction Prevotella glycoprotein (PGP). The PGP fraction showed strong mitogenicity on splenocytes and cytokine-inducing activities on peritoneal macrophages from both C3H/HeJ and C3H/HeN mice, and it stimulated human gingival fibroblasts to produce cytokines. The activities of the PGP fraction were resistant to heat inactivation (100 degrees C for 1 h) and protease treatments and were scarcely inhibited by polymyxin B. In contrast, the purified lipopolysaccharide fraction (LPS-PCP) extracted from the same bacterium with a phenol-chloroform-petroleum ether mixture, which showed strong Limulus activity and a single low-molecular-weight band (approximately 3,000) on DOC-PAGE, lacked the activities on splenocytes and macrophages from C3H/HeJ mice and human gingival fibroblasts. The activities of the LPS-PCP fraction on cells from C3H/HeN mice were completely inhibited by polymyxin B. The LPS extracted from the same bacterium with hot phenol-water (LPS-PW) exhibited the properties of both the PGP fraction and the LPS-PCP fraction. These findings suggest that the unique bioactivities of the LPS-PW fraction of oral black-pigmented bacteria reported to date, which differed from those of the classical endotoxin, were derived from the PGP fraction and not from the LPS itself.

Cardiovascular risk factors and hyperinsulinemia in elderly men: the Honolulu Heart Program

Associations of cardiovascular risk factors, including several measures of adiposity, with hyperinsulinemia were assessed in 3562 elderly (71 to 93 years of age) Japanese American men from the Honolulu Heart Program who were examined between 1991 and 1993. In addition, cardiovascular risk factors measured 25 years earlier were also examined in relation to hyperinsulinemia. Hyperinsulinemia was defined as fasting insulin > or = 95th percentile (20 microU/mL) among the subset of subjects (n = 504) who were nonobese and free of clinical diabetes and glucose intolerance. When this definition was applied to the entire population, the prevalence of hyperinsulinemia declined cross-sectionally with age (P < 0.001) from 24.2% in men aged 71 to 74 years to 16.4% in men aged 85 to 93 years. Factors having a positive and independent association with hyperinsulinemia included body mass index (BMI), triglycerides, glucose, hematocrit, use of diabetic medication, heart rate, and hypertension. The association with physical activity was negative. Triglycerides, BMI, diabetic medication, hypertension, and smoking levels measured 25 years earlier were also associated independently with hyperinsulinemia. Associations were similar in nondiabetic subjects. Three measures of adiposity (BMI, waist circumference, and subscapular skinfold thickness) were independently related to hyperinsulinemia cross-sectionally. However, associations involving a difference between the 80th and 20th percentiles in each adiposity measure appeared strongest for BMI (odds ratio (OR) = 4.5, 95% confidence interval (CI) = 3.7 to 5.6) and waist circumference (OR = 4.1, 95% CI = 3.3-5.1) and slightly weaker for subscapular skinfold thickness (OR = 2.1, 95% CI = 1.8-2.5). These findings suggest that features of an insulin resistance syndrome including dyslipidemia, glucose intolerance, hypertension, and obesity, assessed both cross-sectionally and 25 years previously, are associated independently with hyperinsulinemia in elderly Japanese American men.

Developmental pattern of axonal pathways in the house shrew maxillary nerve

The topographic patterns of peripheral receptors and effectors seem to contribute to the construction of the neuronal circuit in the central nervous system (CNS) in mammals. Many patterns replicating those of the periphery have been found in the CNS, and fasciculation has been regarded as having a central role in the pattern replication. The house shrew, Suncus murinus, is an excellent species in which to study this topic because it has a vibrissae system arranged in a single ordered fashion and extraordinarily well-developed trigeminal spinal tracts. Using immunostaining and retrograde-tracing techniques, we examined the developmental pattern of the maxillary nervous system in the house shrew. The results indicate that the basic pattern of axonal extension reiterates with a parallel arrangement throughout the course of development except at a site in the brainstem where the central processes bifurcate into ascending and descending branches. Dorsoventral inversion of the peripheral pattern in the spinal tract occurs with this dual-leveled bifurcation in association with the mediolaterally ordered entry of the central processes into the brainstem. The basic pattern of the central processes is established prior to the appearance of the vibrissae, indicating that the basic topographic pattern of the maxillary nerve is not related to the vibrissae system. The fasciculation pattern does not correspond to the overall layout of the arrays of vibrissae, and there are frequent exchanges of axons between fascicles both in the periphery and centrally. The parallel organization of the majority of the processes, together with the free exchange of processes between fascicles, suggests that these processes have an important role in the formation of the fasciculation and somatotopic patterns.

Lipoteichoic acid and interleukin 1 stimulate synergistically production of hepatocyte growth factor (scatter factor) in human gingival fibroblasts in culture

Lipoteichoic acids (LTA) from various gram-positive bacteria, including oral streptococci such as Streptococcus sanguis, enhanced the production of hepatocyte growth factor (HGF) (scatter factor) by human gingival fibroblasts in culture, whereas lipopolysaccharides (LPS) from various gram-negative bacteria did not. In contrast, LPS induced interleukin 1 activity in human gingival epithelial cells in culture, while LTA had little effect. LTA and recombinant human interleukin 1 alpha enhanced synergistically the production of HGF/SF in human gingival fibroblast cultures. Recombinant human HGF, in turn, enhanced the proliferation of human gingival epithelial cells in culture.

Distribution and correlates of insulin in elderly men. The Honolulu Heart Program

The role of insulin in cardiovascular disease is uncertain, and studies in elderly or minority populations are infrequent. Fasting and 2-hour insulin concentrations and their cross-sectional associations with cardiovascular risk factors were examined in 3562 elderly (aged 71 to 93 years) Japanese American men from the Honolulu Heart Program who were reexamined between 1991 and 1993. Insulin distributions were skewed (mean and median: 16.8 and 12 microU/mL for fasting; 117.2 and 93 microU/mL for 2-hour); fasting but not 2-hour insulin levels declined significantly with age (P < .0001 and P = .54, respectively). Factors most strongly correlated with insulin included measures of obesity, fat distribution, and levels of triglyceride, glucose (r = .38 to r = .50 fasting, r = .21 to r = .27 2-hour), and HDL cholesterol (r = -.41 and r = -.22, respectively). Other correlates included fibrinogen, hematocrit, heart rate, blood pressure, cigarettes per day (all positive), alcohol, physical activity, and forced vital capacity (negative). Associations were also evident across risk factor quintiles. Insulin levels were significantly elevated in men with hypertension and diabetes. In multiple linear regression analyses, log10 fasting insulin was positively and independently associated with body mass index, triglycerides, glucose, fibrinogen, hematocrit, heart rate, diabetes, and hypertension and negatively associated with HDL cholesterol, physical activity, and forced vital capacity. In general, results were similar for log10 2-hour insulin and when subjects who fasted < 12 hours or had diabetes were excluded. Substitution of medication use and blood pressure for hypertension indicated independent associations of medication use but not blood pressure with insulin.(ABSTRACT TRUNCATED AT 250 WORDS)

Molecular and structural requirements of a lipoteichoic acid from Enterococcus hirae ATCC 9790 for cytokine-inducing, antitumor, and antigenic activities

Comparison was made between the immunobiological and antigenic properties of two lipoteichoic acid (LTA) fractions (LTA-1 and -2) from Enterococcus hirae ATCC 9790, their glycolipid portions, and synthetic compounds partially mimicking the above bacterial products. The more lipophilic LTA-2 fraction was capable of inducing serum tumor necrosis factor alpha and interleukin-6 in muramyldipeptide-primed mice and serum gamma interferon in those primed with Propionibacterium acnes. The LTA-2 fraction also induced tumor necrosis factor alpha, interleukin-6, and thymocyte-activating factor (essentially interleukin-1) in murine peritoneal macrophage cultures. Consecutive intravenous injections of muramyldipeptide and the LTA-2 fraction in Meth A fibrosarcoma-bearing BALB/c mice caused hemorrhagic necrosis and marked regression leading to complete regression of the tumor with no accompanying weakening or lethal effects. The LTA-2 fraction was at least 10,000-fold less pyrogenic in rabbits than a reference endotoxic lipopolysaccharide. The more hydrophilic LTA-1 fraction, on the other hand, showed at most marginal activity in the in vivo and in vitro assays. Natural glycolipids (NGL-1 and -2) which were prepared from a chloroform-methanol extract of Streptococcus pyogenes and E. hirae cells, and comparable in structure to the lipid moieties of the LTA-1 and -2 fractions, respectively, were practically inactive in all of the assays. None of the test synthetic compounds was immunobiologically active, although synthetic partial counterparts of the structure of LTA proposed by W. Fischer (Handb. Lipid Res. 6:123-234, 1990) reacted with murine monoclonal antibody TS-2, which was raised against OK-432, a penicillin-killed S. pyogenes preparation, and capable of neutralizing the cytokine-inducing activities of the LTA-2 fraction.

Immunobiological activities of a 55-kilodalton cell surface protein of Prevotella intermedia ATCC 25611

A protein was extracted from whole cells of Prevotella intermedia ATCC 25611 with sodium lauroylsarcosine and purified by chromatography on a DEAE-Sepharose fast-flow column. The The apparent molecular weight of the protein was 55,000. A mouse polyclonal antibody specific for the protein recognized the cell surface structure of P. intermedia and also reacted with proteins in lysates of other black-pigmented anaerobic bacteria, such as Porphyromonas endodontalis and Prevotella melaninogenica, but not with those in lysates of Porphyromonas gingivalis or with the purified fimbriae of P. gingivalis 381. The N-terminal sequence of the 55-kDa protein showed only low homology with the cell surface proteins of any black-pigmented bacteria reported to date. The level of immunoglobulin G antibody to the antigen was higher in the sera of patients with periodontitis than in the sera of healthy volunteers. The protein induced interleukin-1 alpha, -1 beta, -6, and -8 and tumor necrosis factor alpha in human peripheral blood mononuclear cell cultures and interleukin-1 beta and -6 in human umbilical vascular endothelial cell and gingival fibroblast cultures. The protein induced interleukin-6 and tumor necrosis factor alpha activities in peritoneal macrophages from C3H/HeJ as well as from C3H/HeN mice and also induced cytokine activities in the sera of both strains of mice primed with muramyldipeptide.

Characterization of purified autoantibodies to the insulin receptor from six patients with type B insulin resistance

Anti-insulin-receptor autoantibodies are present in the serum of patients with the type B syndrome of extreme insulin resistance. Sera from six patients with this syndrome were purified over protein-A agarose to remove insulin and other serum factors and obtain an immunoglobulin fraction. These purified fractions were used to quantitatively determine the antibodies' activity in three separate assays. The ability to inhibit insulin binding was determined in an assay using fibroblasts that overexpress the human insulin receptor; the ability to immunoprecipitate the receptor was determined in an assay using biosynthetically labeled insulin receptors rather than insulin cross-linked receptors; and the ability to stimulate glucose oxidation was determined in isolated adipocytes. We show that the ability of these antibodies to inhibit insulin binding is tightly coupled to their ability to immunoprecipitate the biosynthetically labeled receptor, but neither assay predicts the bioactivity of these immunoglobulins. We suggest that the inability to show this tight coupling in the past may be due to methodological differences. We find no evidence that these antibodies are anti-idiotypic antibodies.

Persistent or recurrent acromegaly. Long-term endocrinologic efficacy and neurologic safety of postsurgical radiation therapy

As in other clinics, pituitary surgery was definitive treatment in less than 50% of cases of acromegaly treated at one institution over several decades. From 1965 to 1989, 24 acromegalic patients who had noncurative pituitary surgery received radiation therapy at the National Institutes of Health, with a basal human growth hormone level of greater than 5 ng/ml as the criterion for active disease. Using megavoltage irradiation, more than 60% of these patients stabilized at a normal hormonal range, and the overwhelming majority had decreasing growth hormone levels with time. No major side effects of irradiation were encountered except panhypopituitarism of varying degrees. The authors evolved a policy of surgery as the first option, followed by irradiation for patients with postoperative growth hormone levels more than 5 ng/ml.

Biosynthesis and regulation of the insulin receptor

The insulin receptor is an integral glycoprotein of the plasma membrane in most mammalian cells. The gene encodes a 190 kDa proreceptor that undergoes a number of processing steps. The gene is constitutively expressed, but at least one form of regulation has been demonstrated. Glucocorticoids increase the number of insulin receptors on the surface of cultured human lymphocytes, a process which is accompanied by an increase in transcription of the gene. N-linked glycosylation and amide-linked acylation occur as co-translational events. Subsequently, the proreceptor is cleaved into alpha and beta subunits; the subunits then undergo an ester-linked acylation step and N-linked complex glycosylation. In addition, O-linked glycosylation has been recently described in the beta subunit. The mature insulin receptor is inserted into the plasma membrane as an alpha 2-beta 2 disulfide-linked heterodimer. The receptor can be further regulated on the cell surface by insulin binding and receptor-mediated endocytosis. The receptor concentration on the cell surface then becomes a function of the internalization rate and the receptor recycling rate. Receptor regulation is a relevant feature of many forms of clinical insulin resistance, and recently genetic mutations have been described that determine both the binding properties of the receptor and its translocation and processing properties.

Interleukin-1 beta is a potent growth inhibitor of adult rat hepatocytes in primary culture

Interleukin-1 beta (IL-1 beta) strongly inhibited DNA synthesis of adult rat hepatocytes in primary culture stimulated by insulin and epidermal growth factor (EGF). Its effect was dose-dependent and was maximal at 2 ng/ml. IL-1 beta had no cytotoxic effect but changed the cells from a flat to a spindle shape as shown by phase-contrast microscopy. The inhibition of DNA synthesis by IL-1 beta was closely correlated with a decrease in the labeling index. This inhibitory effect was observed only when IL-1 beta was added for 10 h to cultured hepatocytes in the G1 phase within 12 h after addition of insulin and EGF: it was not observed in the S phase, which starts about 24 h after addition of the mitogens. Exposure of the hepatocytes to IL-1 beta for two 1-h periods, one at an early stage (0-6 h) and one at a late stage (6-12 h) of the G1 phase, resulted in the same marked inhibition of DNA synthesis as exposure to IL-1 beta for 10 h in the G1 phase. This requirement of IL-1 beta at two stages in the G1 phase for inhibition of DNA synthesis of hepatocytes is different from that with transforming growth factor-beta, which is required for only 1 h in the early G1 phase for a similar inhibition. These findings suggest that IL-1 beta acts at two distinct stages in the G1 phase and that its cooperative actions are necessary to inhibit growth of adult rat hepatocytes in primary culture. Other cytokines, such as IL-6/B-cell stimulating factor-2, were less potent, but caused significant inhibition of DNA synthesis of adult rat hepatocytes at 2 ng/ml, whereas IL-2 and tumor necrosis factor did not affect hepatocyte growth. From these results it is suggested that Kupffer cells in liver lobules and macrophages in the blood may play important roles, mainly via IL-1, in repair of liver damage and regeneration.

Purified hydrophobic proteins, chargerins, are essential for energy transduction in oxidative phosphorylation

Studies on anisotropic inhibitors, a unique type of inhibitor of energy transduction in oxidative phosphorylation, suggested that redox reactions generate two kinds of negative charges on the outer surface of mitochondrial inner membranes, on redox complexes and on F0, and that the inhibitors inhibit energy transduction by binding to these negative charges. Recent experiments on photoaffinity labeling of mitochondria with monoazide ethidium, which is an anisotropic inhibitor, showed that the inhibitor specifically binds to a hydrophobic protein of the membranes. In the present work the mitochondrial components labeled with monoazide ethidium were further purified and two kinds of hydrophobic proteins (apparent molecular masses, 8 and 13 kDa) were found to be specifically labeled with the inhibitor. These proteins were named chargerin I and II, respectively. Redox reactions greatly increased the molar ratio of ethidium bound to chargerin I and II in mitochondria, reflecting a conformational change of the chargerins coupled with the redox reactions. It was also shown that antibody against chargerin II specifically inhibited ATP synthesis in mitoplasts (inner membranes plus matrix) prepared from rat liver mitochondria. Thus, the present findings show that chargerins have an essential role in energy transduction in oxidative phosphorylation in rat liver mitochondria, in good accord with the conformational coupling model of the H+ pumps and ATP synthesis.

Triphenyltetrazolium and its derivatives are anisotropic inhibitors of energy transduction in oxidative phosphorylation in rat liver mitochondria

Triphenyltetrazolium and its derivatives inhibited energy transduction in mitochondria but not in submitochondrial particles, which are inside-out relative to the membranes of mitochondria. Triphenyltetrazolium incorporated into the inside of submitochondrial particles inhibited ATP synthesis in the particles. Triphenyltetrazolium also inhibited the reduction of NAD by succinate coupled with oxidation of succinate by O2 and hydrolysis of ATP. Energization of mitochondrial inner membranes with succinate and with ATP induced sites on the membranes for triphenyltetrazolium and its derivatives. The maximum amounts of energy-dependent binding sites for triphenyltetrazolium on membranes energized with succinate and ATP, respectively, were 14 and 4 nmol/mg protein. Triphenyltetrazolium also induced H+ ejection from the energized membranes. The maximum amounts of H+ ejection from membranes energized with succinate and ATP, respectively, were 4 and 2.4 nmol/mg protein. Triphenyltetrazolium also decreased the membrane potential up to about half the control value and caused shrinkage of mitochondria in an energy-dependent fashion. Comparison of the Hammett's sigma constants of triphenyltetrazolium derivatives with various substituents on the 3-benzene ring showed that lower concentrations of triphenyltetrazolium derivatives with a stronger positive charge were required for inhibition of energy transduction. The present findings show that triphenyltetrazolium and its derivatives act as anisotropic inhibitors of energy transduction by binding to negative charges created on the outer side (C-side) of energized mitochondria, and that the positive charge of these inhibitors is one of important factors for their inhibitory activity. These negative charges may be an essential part of the H+ pump.