Profiles of central nervous system surgical site infections in endoscopic transnasal surgery exposing the intradural space

OBJECTIVE

Despite its efficacy and minimal invasiveness, the clean-contaminated nature of endoscopic transnasal surgery (ETS) may be susceptible to central nervous system surgical site infections (CNS-SSIs), especially when involving intradural exposure. However, the profiles of ETS-associated CNS-SSIs are not fully elucidated.

METHODS

The institutional ETS cases performed between May 2017 and March 2023 were retrospectively analysed. The incidences of CNS-SSIs were calculated, and their risk factors examined.

RESULTS

The incidence of CNS-SSIs was 2.3% (7/305) in the entire cohort and 5.0% (7/140) in ETSs with intradural exposure. All the CNS-SSIs were meningitis and developed following ETS with intradural exposure. The incidences were 0%, 5.6% and 5.8% in ETSs with Esposito grade 1, 2 and 3 intraoperative cerebrospinal fluid leakage, respectively. Among the pre- and intra-operative factors, body mass index (unit odds ratio (OR), 0.62; 95% confidence interval (CI), 0.44-0.89; P<0.01), serum albumin (unit OR, 0.03; 95% CI, 0.0007-0.92; P=0.02), and American Society of Anesthesiologists physical status score (unit OR, 20.7; 95% CI, 1.65-259; P<0.01) were significantly associated with CNS-SSIs. Moreover, postoperative cerebrospinal fluid leakage was also significantly associated with CNS-SSIs (OR, 18.4; 95% CI, 3.55-95.0; P<0.01).

CONCLUSIONS

The incidence of ETS-associated CNS-SSIs is acceptably low. Intradural exposure was a prerequisite for CNS-SSIs. Malnutrition and poor comorbidity status should be recognized as important risks for CNS-SSIs in ETS.

Tracing and regulating redox homeostasis of model benthic ecosystems for sustainable aquaculture in coastal environments

Aquaculture in coastal environments has an increasingly important role in the world’s food supply; however, the accumulation of organic compounds on seafloors due to overfeeding adversely affects benthic ecosystems. To assess the ecological resilience of aquafarms to nutrient influx, we investigated the redox homeostasis of benthic ecosystems using a marine oligochaete as a model benthic organism in aquaculture fields. Real-time monitoring of the redox potential of a model benthic ecosystem constructed in an electrochemical reactor allowed evaluation of the homeostatic response of the system to nutrient addition. Although the detrimental effects of overfeeding were confirmed by irreversible potential changes in the sediment, redox homeostasis was reinforced through a cooperative relationship between oligochaetes and sediment microorganisms. Specifically, the oligochaetes exhibited reversible changes in metabolism and body position in response to dynamic changes in the sediment potential between −300 and 500 mV, thereby promoting the decomposition of organic compounds. The potential-dependent changes in metabolism and body position were reproduced by artificially manipulating the sediment potential in electrochemical reactors. Given the importance of benthic animals in sustaining coastal ecosystems, the electrochemical monitoring and physiologic regulation of marine oligochaetes could offer an intriguing approach toward sustainable aquaculture.

Nitrite as a causal factor for nitrate-dependent anaerobic corrosion of metallic iron induced by Prolixibacter strains

Microbially influenced corrosion (MIC) may contribute significantly to overall corrosion risks, especially in the gas and petroleum industries. In this study, we isolated four Prolixibacter strains, which belong to the phylum Bacteroidetes, and examined their nitrate respiration- and Fe0 -corroding activities, together with two previously isolated Prolixibacter strains. Four of the six Prolixibacter strains reduced nitrate under anaerobic conditions, while the other two strains did not. The anaerobic growth of the four nitrate-reducing strains was enhanced by nitrate, which was not observed in the two strains unable to reduce nitrate. When the nitrate-reducing strains were grown anaerobically in the presence of Fe0 or carbon steel, the corrosion of the materials was enhanced by more than 20-fold compared to that in aseptic controls. This enhancement was not observed in cultures of the strains unable to reduce nitrate. The oxidation of Fe0 in the anaerobic cultures of nitrate-reducing strains occurred concomitantly with the formation of nitrite. Since nitrite chemically oxidized Fe0 under anaerobic and aseptic conditions, the corrosion of Fe0 - and carbon steel by the nitrate-reducing Prolixibacter strains was deduced to be mainly enhanced via the biological reduction of nitrate to nitrite, followed by the chemical oxidation of Fe0 to Fe2+ and Fe3+ coupled to the reduction of nitrite.

CENP-B creates alternative epigenetic chromatin states permissive for CENP-A or heterochromatin assembly

CENP-B binds to CENP-B boxes on centromeric satellite DNAs (known as alphoid DNA in humans). CENP-B maintains kinetochore function through interactions with CENP-A nucleosomes and CENP-C. CENP-B binding to transfected alphoid DNA can induce de novo CENP-A assembly, functional centromere and kinetochore formation, and subsequent human artificial chromosome (HAC) formation. Furthermore, CENP-B also facilitates H3K9 (histone H3 lysine 9) trimethylation on alphoid DNA, mediated by Suv39h1, at ectopic alphoid DNA integration sites. Excessive heterochromatin invasion into centromere chromatin suppresses CENP-A assembly. It is unclear how CENP-B controls such different chromatin states. Here, we show that the CENP-B acidic domain recruits histone chaperones and many chromatin modifiers, including the H3K36 methylase ASH1L, as well as the heterochromatin components Suv39h1 and HP1 (HP1α, β and γ, also known as CBX5, CBX1 and CBX3, respectively). ASH1L facilitates the formation of open chromatin competent for CENP-A assembly on alphoid DNA. These results indicate that CENP-B is a nexus for histone modifiers that alternatively promote or suppress CENP-A assembly by mutually exclusive mechanisms. Besides the DNA-binding domain, the CENP-B acidic domain also facilitates CENP-A assembly de novo on transfected alphoid DNA. CENP-B therefore balances CENP-A assembly and heterochromatin formation on satellite DNA.

KAT7/HBO1/MYST2 Regulates CENP-A Chromatin Assembly by Antagonizing Suv39h1-Mediated Centromere Inactivation

Centromere chromatin containing histone H3 variant CENP-A is required for accurate chromosome segregation as a foundation for kinetochore assembly. Human centromere chromatin assembles on a part of the long α-satellite (alphoid) DNA array, where it is flanked by pericentric heterochromatin. Heterochromatin spreads into adjacent chromatin and represses gene expression, and it can antagonize centromere function or CENP-A assembly. Here, we demonstrate an interaction between CENP-A assembly factor M18BP1 and acetyltransferase KAT7/HBO1/MYST2. Knocking out KAT7 in HeLa cells reduced centromeric CENP-A assembly. Mitotic chromosome misalignment and micronuclei formation increased in the knockout cells and were enhanced when the histone H3-K9 trimethylase Suv39h1 was overproduced. Tethering KAT7 to an ectopic alphoid DNA integration site removed heterochromatic H3K9me3 modification and was sufficient to stimulate new CENP-A or histone H3.3 assembly. Thus, KAT7-containing acetyltransferases associating with the Mis18 complex provides competence for histone turnover/exchange activity on alphoid DNA and prevents Suv39h1-mediated heterochromatin invasion into centromeres.

•

The histone acetyltransferase KAT7 positively regulates centromeric CENP-A assembly

•

Human Mis18 complex is a scaffold for assembly of KAT7 and HJURP, a CENP-A chaperone

•

KAT7 or RSF1 stimulates histone turnover/exchange on alphoid DNA

•

KAT7 antagonizes H3K9-trimethylase Suv39h1-mediated centromere inactivation

Epigenetic engineering shows that a human centromere resists silencing mediated by H3K27me3/K9me3

Centromeres are embedded within heterochromatin but are transcriptionally active. Centromeric transcription and the centromere function of a human artificial chromosome resist repression mediated by nucleation of repressive marks H3K27me3 or H3K9me3 via tethering of EZH2 or the SET domain of Suv39h1, respectively.

Centromeres are characterized by the centromere-specific H3 variant CENP-A, which is embedded in chromatin with a pattern characteristic of active transcription that is required for centromere identity. It is unclear how centromeres remain transcriptionally active despite being flanked by repressive pericentric heterochromatin. To further understand centrochromatin’s response to repressive signals, we nucleated a Polycomb-like chromatin state within the centromere of a human artificial chromosome (HAC) by tethering the methyltransferase EZH2. This led to deposition of the H3K27me3 mark and PRC1 repressor binding. Surprisingly, this state did not abolish HAC centromere function or transcription, and this apparent resistance was not observed on a noncentromeric locus, where transcription was silenced. Directly tethering the reader/repressor PRC1 bypassed this resistance, inactivating the centromere. We observed analogous responses when tethering the heterochromatin Editor Suv39h1-methyltransferase domain (centromere resistance) or reader HP1α (centromere inactivation), respectively. Our results reveal that the HAC centromere can resist repressive pathways driven by H3K9me3/H3K27me3 and may help to explain how centromeres are able to resist inactivation by flanking heterochromatin.

CENP-C and CENP-I are key connecting factors for kinetochore and CENP-A assembly

Although it is generally accepted that chromatin containing the histone H3 variant CENP-A is an epigenetic mark maintaining centromere identity, the pathways leading to the formation and maintenance of centromere chromatin remain unclear. We previously generated human artificial chromosomes (HACs) whose centromeres contain a synthetic alpha-satellite (alphoid) DNA array containing the tetracycline operator (alphoid^tetO). We also obtained cell lines bearing the alphoid^tetO array at ectopic integration sites on chromosomal arms. Here, we have examined the regulation of CENP-A assembly at centromeres as well as de novo assembly on the ectopic arrays by tethering tetracycline repressor (tetR) fusions of substantial centromeric factors and chromatin modifiers. This analysis revealed four classes of factors that influence CENP-A assembly. Interestingly, many kinetochore structural components induced de novo CENP-A assembly at the ectopic site. We showed that these components work by recruiting CENP-C and subsequently recruiting M18BP1. Furthermore, we found that CENP-I can also recruit M18BP1 and, as a consequence, enhances M18BP1 assembly on centromeres in the downstream of CENP-C. Thus, we suggest that CENP-C and CENP-I are key factors connecting kinetochore to CENP-A assembly.

Highlighted Article: Tethering analysis using various centromere and kinetochore factors, and chromatin modifiers reveals that CENP-C and CENP-I are key connecting factors for kinetochore and CENP-A assembly.

Nap1 regulates proper CENP-B binding to nucleosomes

CENP-B is a widely conserved centromeric satellite DNA-binding protein, which specifically binds to a 17-bp DNA sequence known as the CENP-B box. CENP-B functions positively in the de novo assembly of centromeric nucleosomes, containing the centromere-specific histone H3 variant, CENP-A. At the same time, CENP-B also prevents undesired assembly of the CENP-A nucleosome through heterochromatin formation on satellite DNA integrated into ectopic sites. Therefore, improper CENP-B binding to chromosomes could be harmful. However, no CENP-B eviction mechanism has yet been reported. In the present study, we found that human Nap1, an acidic histone chaperone, inhibited the non-specific binding of CENP-B to nucleosomes and apparently stimulated CENP-B binding to its cognate CENP-B box DNA in nucleosomes. In human cells, the CENP-B eviction activity of Nap1 was confirmed in model experiments, in which the CENP-B binding to a human artificial chromosome or an ectopic chromosome locus bearing CENP-B boxes was significantly decreased when Nap1 was tethered near the CENP-B box sequence. In contrast, another acidic histone chaperone, sNASP, did not promote CENP-B eviction in vitro and in vivo and did not stimulate specific CENP-B binding to CENP-A nucleosomes in vitro. We therefore propose a novel mechanism of CENP-B regulation by Nap1.

Regulation of muscle genes by moderate exercise

Moderate-intensity exercise at the lactate threshold (LT) is considered to be a safe and effective training regimen for improving metabolic syndrome. The aim of the current study was to investigate the effects of moderate exercise performed at the LT on skeletal muscle gene expression. 6 healthy men participated in cycle ergometer training at LT, 60 min/d, 5 d/wk for 12 wks. Muscle samples were collected after 5 d of training, and then 2 d after training at wks 6 and 12. Quantitative real-time PCR analysis revealed that the expression of peroxisome proliferator activated receptor co-activated 1alpha was significantly increased at 1 h after the training session on day 5. Moreover, using serial analysis gene expression, we found that moderate training for 6 and 12 wks simultaneously induced the expression of a number of metabolic genes involved in the TCA cycle, beta-oxidation, and electron transport. Furthermore, several genes encoding antioxidant enzymes and contractile apparatus were induced. The expression levels of 233 novel transcripts were also altered in response to moderate exercise. Thus, moderate training at the LT is a sufficient stimulus to induce the expression of numerous genes implicated in the development of metabolic syndrome, transcripts involved in the contractile apparatus, and novel transcripts.

Gene expression profile of sprinter's muscle

We have characterized the global gene expression profile in left vastus lateralis muscles of sprinters and sedentary men. The gene expression profile was analyzed by using serial analysis of gene expression (SAGE) method. The abundantly expressed transcripts in the sprinter's muscle were mainly involved in contraction and energy metabolism, whereas six transcripts were corresponding to potentially novel transcripts. Thirty-eight transcripts were differentially expressed between the sprinter and sedentary individuals. Moreover, sprinters showed higher expressions of both uncharacterized and potentially novel transcripts. Sprinters also highly expressed seven transcripts, such as glycine-rich protein, myosin heavy polypeptide (MYH) 2, expressed sequence tag similar to (EST) fructose-bisphosphate aldolase 1 isoform A (ALDOA), glyceraldehyde-3-phosphate dehydrogenase and ATP synthase F0 subunit 6. On the other hand, 20 transcripts such as MYH1, tropomyosin 2 and 3, troponin C slow, C2 fast, I slow, T1 slow and T3 fast, myoglobin, creatine kinase, ALDOA, glycogen phosphorylase, cytochrome c oxidase II and III, and NADH dehydrogenase 1 and 2 showed lower expression levels in the sprinters than the sedentary controls. The current study has characterized the global gene expressions in sprinters and identified a number of transcripts that can be subjected to further mechanistic analysis.

The I allele of the angiotensin-converting enzyme gene is associated with an increased percentage of slow-twitch type I fibers in human skeletal muscle

The insertion (I) allele of the human angiotensin-converting enzyme (ACE) gene is associated with lower serum and tissue ACE activity, and with greater endurance performance and enhanced mechanical efficiency of trained muscle. We tested the hypothesis that the ACE-I allele may be associated with increased slow-twitch fiber, which is more efficient than fast-twitch fiber in low-velocity contraction, by examining the association between the ACE genotype and skeletal muscle fiber (SMF) types in 41 untrained healthy young volunteer subjects (31 males, 10 females, age 24 +/- 3 years). Skeletal muscle samples were taken from the left vastus lateralis using the needle-biopsy method. Slow-twitch type I fibers and fast-twitch type IIa and IIb fibers were classified histochemically based on staining for myosin adenosine triphosphatase (ATPase) activity at different pH values. Amylase-periodic acid-Schiff staining was used to visualize capillaries around fibers. ACE-II subjects had significantly (p < 0.01) higher percentages of type I fibers (50.1 +/- 13.9%vs 30.5 +/- 13.3%) and lower percentages of type IIb fibers (16.2 +/- 6.6%vs 32.9 +/- 7.4%) than ACE-DD subjects. The linear trends for decreases in type I fibers and increases in type IIb fibers from ACE-II --> ID --> DD genotypes were significant as assessed by an analysis of variance. The ratio of type I:II fibers also differed according to the ACE genotype. A multivariate logistic regression analysis showed that the ACE-I allele had significant additive and recessive (codominant) effects on the increased type I fibers and the ratio of type I:II fibers. No specific pattern of capillarization was observed among the three ACE genotypes. In conclusion, the ACE-I allele was associated with increased type I SMF, which may be a mechanism for the association between the ACE genotype and endurance performance.

Lifestyle-related risk factors for total and cancer mortality in men and women

We conducted a 14-year follow-up study to analyze the hazard ratio (HR) of mortality regarding lifestyle-related factors in Saga Prefecture, Japan. The subjects included 2,170 people, who were randomly selected from men and women aged from 40 to 69 years old, and who also completed the standardized questionnaire on lifestyle in 1983. Information about death and corresponding data were obtained either by mail and/or through the city offices in 1997. We found that a lower body weight, a lower physical fitness level, not consuming a balanced diet, and cigarette smoking to be significantly elevated risks for all-causes of death in males after adjustment by age and health status. In addition, these results did not change even after excluding subjects for early death. The HR of the female subjects who quit smoking was significantly high, although it changed to insignificant after excluding subjects for early death. These results suggested that being underweight might be an index of a positive risk of death, while maintaining a higher physical fitness level, being careful to consume a more balanced diet, and non smoking all appear to be indexes of a negative risk of death. In addition, these results might also be considered good evidence for improving poor health habits in health promotion activities.

[Bone mineral density of the calcaneus and related factors in men]

In this cross-sectional study, the bone mineral density of the calcaneus was investigated in healthy young (n = 35, 22-33 years) and middle-aged (n = 49, 45-59 years) men. The relationships among the bone mineral density, body fatness, physical fitness, physical activity in recent and past days, smoking, alcohol, and sex hormones (free testosterone, estradiol, and dehydroepiandrosterone-sulfate; DHEA-S) and sex hormone binding globulin were evaluated. The speed of sound (SOS), broadband ultrasound attenuation (BUA) and stiffness were measured by ultrasonic measurement. There was no association between age and bone density in each group. In the young group, there was a positive correlation between the body mass index (BMI) and BUA and between the training time during junior high school and BUA, and an inverse correlation between alcohol consumption and SOS after adjustment for the confounding factors using partial correlation analysis. The level of DHEA-S was weakly but not significantly associated with BUA. In the middle-aged group, there was an inverse correlation between the waist to hip ratio and SOS, and between the height of jump and SOS after adjustment for the confounding factors using partial correlation analysis. These results suggest that different factors may affect bone density in the young and middle-aged men. In young men, the higher BMI and the longer training time during boyhood may have a positive effect, and heavy alcohol consumption may have a negative effect on bone density. In middle-aged men, abdominal fat accumulation has a negative effect and leg muscle power has a positive effect on bone density.

Th1-biased immune responses induced by DNA-based immunizations are mediated via action on professional antigen-presenting cells to up-regulate IL-12 production

The efficacy of DNA-based immunization in conferring protective immunity against certain microbial pathogens including human immunodeficiency virus type 1 (HIV-1) has been described. The potential advantage of DNA-based immunization over the traditional vaccines largely results from its capacity to efficiently induce Th1-biased immune responses against an encoded antigen. We describe how Th1-biased immune responses are induced by DNA-based immunization, using a DNA vaccine construct encoding HIV-1 gp160 cDNA and an eukaryotic expression plasmid carrying murine IFN-gamma cDNA. Transfection of an eukaryotic expression plasmid carrying immunostimulatory sequences (ISS) as well as a gene of interest (DNA vaccine) into professional antigen presenting cells (APC) induced transactivation of IL-12 mRNA, which resulted in antigen-specific Th1-biased immune responses against the encoded antigen. Th1-biased immune responses induced by DNA-based immunization were substantially upregulated by a codelivery of an ectopic IFN-gamma expression system, and this augmentation was mediated via action on professional antigen presenting cells to upregulate IL-12 production. Taken together, it appears likely that Th1-biased immune responses induced by DNA-based immunization are mediated via action on professional antigen-presenting cells to produce IL-12. Interestingly, the model provided strikingly resembles that previously described in infection with Listeria monocytogenes, an intracellular Gram-positive bacterium that induces strong Th1-biased immune responses. The result suggests that DNA-based immunization mimics certain aspects of natural infection with microbial organisms like attenuated vaccines, which in turn provides a rationale to the question of why DNA-based immunization so efficiently induces protective immunity against these microbial pathogens.

[Changes in the activity of neutral and acidic isoforms of sphingomyelinase in hepatoma-22, regenerating and ischemic liver]

Activity of neutral and acidic sphingomyelinases (N- and A-SMases) were studied in regenerating liver after partial hepatectomy (during 48 hrs after operation), in ischemic liver during 15, 30 min and 1 and 2 hrs ischemia and during following reperfusion (from 5 min up to 2 hrs), in hepatoma- 22 after 15 days of transplantation and in liver of tumor bearing animals. It was shown that activity of N-SMase is increased in hepatoma-22 and in regenerating liver and it is decreased in ischemic liver. Following reperfusion of ischemic liver area activity of enzyme was found to have returned to baseline in dependence on time of ischemia and reperfusion. Activity of A-SMase is decreased in tumor, is not changed in regenerating liver and increased after long time of ischemia. It was supposed that N-SMase is involved in cell proliferation, but A-SMase is connected with cell damage.

Decreased skeletal muscle capillary density is related to higher serum levels of low-density lipoprotein cholesterol and apolipoprotein B in men

The relationships between skeletal muscle morphology, particularly muscle fiber capillary density, and serum lipid profiles were evaluated in 25 non-obese men aged 18 to 36 years (body mass index [BMI], 22.7 +/- 2.5 kg/m2; body fat, 13.6% +/- 4.0%, maximal oxygen uptake [VO2max], 46.2 < or = 6.3 mL/kg/min). Skeletal muscle samples were taken from the vastus lateralis using the needle-biopsy method. The fiber types (I, IIa, and IIx) and their percent distribution, the indices of capillary density, and the diffusion index expressed as the cross-sectional area occupied by one capillary were determined. Blood samples were drawn from the antecubital vein after a 12-hour fast. Based on Pearson's correlation analysis, the number of capillaries around type IIx fiber correlated inversely with the serum level of low-density lipoprotein cholesterol ([LDL-C] r = -.50, P < .05). The number of capillaries per fiber (cap/fiber ratio), number of capillaries per area (cap/mm2), and capillaries around each fiber type correlated inversely with the serum level of apolipoprotein B ([apo B] r = -.40 to -.54, P < .05 to .01). Further, the diffusion index for each fiber type correlated positively with LDL-C and apo B (r = .42 to .50, P < .05 to .01). Among 14 subjects in whom high-density lipoprotein cholesterol (HDL-C) subfractions were analyzed, a positive correlation was found between cap/mm2 and HDL2-C (r = .64, P < .05). Partial correlation analysis showed that these correlations either remain or improve after adjusting for age, VO2max, and body fatness. These results indicate that skeletal muscle capillary density and diffusion capacity are related to lipid and apolipoprotein concentrations for both type I and type II fibers.

[A survey of allergic diseases among elementary school children in Saga Prefecture. The first report. Prevalence and past history]

This study was carried out to determine the prevalence of several allergic diseases among elementary school children in Saga prefecture. A questionnaire was distributed to the parents of 2,795 children in 12 elementary schools located in urban, seaside and mountainous areas. The response rate was 92.8%. The prevalence rate of allergic diseases among school children was 24.6% (24.5% for boys and 21.5% for girls). The common types of allergic diseases among boys were allergic rhinitis (11.3%), atopic dermatitis (9.7%), and bronchial asthma (5.7%), and those among girls were atopic dermatitis (9.7%); allergic rhinitis (6.5%), and bronchial asthma (3.7%). Analysis by residential area of the children, showed that the prevalence rate of allergic diseases in total was increased in the order of mountainous (20.8%), seaside (24.1%) and urban area (28.7%). The most common type of allergic diseases was atopic dermatitis in urban and mountainous area, while allergic rhinitis was most common in seaside area.

High blood pressure and muscle morphology/metabolism--causal relationship or only associated factors?

As muscle tissue constitutes a main target organ for glucose metabolism and is responsible for the development of insulin resistance, it seems plausible to elucidate the relationship between blood pressure and muscle morphology and metabolism. The association between blood pressure and capillarization/morphology of the vastus lateralis muscle and metabolic variables was evaluated in 24 perimenopausal obese women [body mass index (BMI) 34.9 +/- 1.1; waist-hip ratio (WHR) 0.90 +/- 0.02]. The muscle enzyme activity of lipoprotein lipase (LPL), citrate synthase and glycogen synthase was determined. There was a significant negative correlation between the percentage of type I fibres and relative fibre area of type I on the one hand and systolic and diastolic blood pressure on the other. There was a negative correlation between the capillary density (i.e. number of capillaries/muscle fibre) and a positive correlation between the diffusion distance (fibre area supplied by one capillary) and diastolic blood pressure. The activities of LPL and citrate synthase were positively correlated with the percentage of type I and negatively correlated with the percentage of type II muscle fibres. The activity of LPL was also negatively correlated with plasma glucose and the insulin/C-peptide ratio. The insulin/C-peptide ratio was positively correlated with the percentage of type II muscle fibres. In stepwise multiple regression analyses, 20-30% of the variation in systolic and diastolic blood pressure could be explained by the variables of muscle fibre distribution. Excluding muscle morphological variables from the regression model, the insulin/C-peptide ratio accounted for 13% of the variation in systolic and diastolic blood pressure. The results of the study show the close association between muscle morphology and blood pressure. It remains to be elucidated whether this association indicates a causal relationship.

Small doses of triiodothyronine can change some risk factors associated with abdominal obesity

OBJECTIVE

To elucidate whether the administration of small doses of triidothyronine (T3) can increase concentrations of sex hormone binding globulin (SHBG) in obese women with different types of obesity and to evaluate the potential metabolic benefits of such treatment.

DESIGN

Daily administration of 20 micrograms of T3 during six weeks while maintaining habitual food intake and physical activity.

SUBJECTS

Seventy premenopausal obese women (age: 41.2 +/- 1.5 y mean +/- s.e.m., body mass index (BMI): 34.4 +/- 0.7).

MEASUREMENTS

Plasma concentrations of SHBG, lipids, insulin, thyroid hormones, sex hormones, blood glucose and insulin sensitivity (by euglycemic insulin clamp in 12 patients) at base line after six weeks of treatment.

RESULTS

Six weeks treatment with small doses of T3 resulted in a significant increase in plasma SHBG. The increase of SHBG was higher in abdominal obesity and not associated with a significant change in body weight, plasma insulin concentration, insulin/glucose ratio of plasma insulin sensitivity (glucose disposal during insulin clamp). In patients with initially high SHBG the significant increase of insulin removal (as judged from the increase of c-peptide/insulin ratio) was observed. Treatment resulted in a reciprocal increase of T3, decrease of thyroxine (T4), and a more than double increase of T3/T4 ratio.

CONCLUSIONS

Administration of small doses of T3 can increase the concentration of SHBG without changing insulin concentrations or sensitivity. As there was a significant decrease (by 36%) of T4 and parallel increase of T3 with a clear increase of T3/T4 ratio it seems possible that rather than lack of thyroid hormones a lower peripheral deiodination of T4 might be a factor contributing to the low SHBG concentration in abdominal obesity. Treatment with small doses of T3 may be considered to ameliorate some of the risk factors associated with abdominal obesity, particularly in some subgroups of obese women with a relative resistance to thyroid hormones possibly dependent on decreased peripheral deiodination of thyroxine.

[Effects of aerobic capacity and body fat accumulation on the insulin response after an oral glucose load]

The effects of aerobic capacity and body fat accumulation on the insulin response after an oral glucose load were investigated in 21 college students. The subjects were divided into three groups based on their insulin response after an oral glucose load: the first group showed a hyper and prolonged insulin response; HI (n = 6), the second group showed a lower insulin response; LI (n = 6), and the third group consisted of other subjects; MI (n = 9). The maximal oxygen consumption in the HI group (29.6 +/- 3.3 ml/kg/min) was significantly lower than that in the LI group (42.5 +/- 3.1 ml/kg/min, P < 0.05). Although no significant difference was observed in the body mass index between the HI (24.6 +/- 1.9) and LI groups (22.2 +/- 0.4, p > 0.05), the body fat and the waist-to-hip ratio were significantly higher in the HI group (25.3 +/- 3.1%, 0.87 +/- 0.03) than in the LI group (12.9 +/- 0.7%, 0.76 +/- 0.01, P < 0.05). All subjects in the LI group performed regular exercise, while none of the subjects in the HI group performed any regular exercise. These results suggest that an inactive life style, decreased aerobic capacity and increased body fat accumulation all appear to result in an increased insulin response after a glucose load.

[Bone mineral density by ultrasonic measurement in pre- and postmenopausal women--relationship with sex hormones and nutritional states]

In this cross-sectional study we evaluated the relationships of the sex hormones, estradiol (E2), free testosterone (free T), dehydroepiandrosterone-sulfate (DHEA-S), sex hormone-binding globulin (SHBG) and nutritional status to bone density assessed by ultrasonic measurements. The subjects were 16 premenopausal (38-50 years) and 28 postmenopausal (47-86 years) women living in a rural area in Yamaguchi Prefecture in Japan. They were healthy and did not smoke or drink. Speed of sound (SOS), broadband ultrasound attenuation (BUA) and the stiffness index (SI) were used as the indices to evaluate ultrasonic bone density (UBD) for the calcaneus. In premenopausal women, the concentration of free T was negatively associated with BUA. The DHEA-S concentration had a significant negative correlation with BUA after adjustments for age and body mass index (BMI). Daily intakes of fat, animal fat, animal protein, calcium (Ca) and vitamin B2 (Vit B2) were positively associated with UBD. In postmenopausal women, although DHEA-S positively correlated with SOS, BUA and SI, the significance disappeared after adjustments for age and BMI. The protein intake was positively associated with BUA. Multiple regression analysis for SOS, BUA and SI as dependent variables was performed. Independent variables were age, BMI, E2, free T, DHEA-S, SHBG and daily intakes of animal fat, animal protein, Vit B2 and Ca. In premenopausal women, the animal fat intake contributed significantly and positively to the variations of SOS and SI. The intake of Vit B2 had a significant positive correlation, and the level of DHEA-S had a significant negative correlation with BUA. In postmenopausal women, age and BMI contributed significantly to the variations of SOS, BUA and SI, while the nutritional variables and the sex hormones were not found to be significant. In conclusion, different factors predicting UBD were suggested for pre- and postmenopausal women. In premenopausal women, daily intakes of animal fat and Vit B2 might be effective to maintain higher bone density. Further investigations are still needed to clarify the relationship between DHEA-S and UBD.

Relationship between plasma concentrations of beta-carotene and alpha-tocopherol and life-style factors and levels of DNA adducts in lymphocytes

beta-Carotene and alpha-tocopherol have been thought to reduce risk of lung cancer. Whether beta-carotene and alpha-tocopherol influence human DNA adducts, indicators of biologically effective doses of carcinogens, has been seldom studied. In this cross-sectional study, we measured plasma beta-carotene and alpha-tocopherol in 192 healthy men and DNA adducts in lymphocytes in 104 of the subjects. Because genetic polymorphism of cytochrome P-4501A1 (CYP1A1) and glutathione S-transferase M1 (GSTM1) has been associated with interference in formation of reactive intermediates and detoxification of polycyclic aromatic hydrocarbons, we also obtained data concerning genetic polymorphism of CYP1A1 and GSTM1. In multiple regression analysis, parameters such as alcohol consumed per day, high-density lipoprotein cholesterol, Quetelet index, and cigarettes smoked per day were correlated inversely, whereas age, plasma alpha-tocopherol, and intake frequency of fruits were correlated positively with plasma beta-carotene concentration. DNA adduct levels of high plasma beta-carotene or alpha-tocopherol groups were not significantly different from the DNA adduct levels of low plasma beta-carotene or alpha-tocopherol groups among current smokers or nonsmokers. In variant states of CYP1A1 or GSTM1 polymorphism, after controlling for effect of cigarettes smoked per day, no significant correlation was found between plasma beta-carotene or alpha-tocopherol and DNA adduct levels. These results indicated that alcohol consumption, cigarette smoking, and plasma alpha-tocopherol have a close relationship with plasma beta-carotene. The plasma beta-carotene and alpha-tocopherol were not likely to influence the level of DNA adducts in lymphocytes.

The relationships of testosterone, estradiol, dehydroepiandrosterone-sulfate and sex hormone-binding globulin to lipid and glucose metabolism in healthy men

We investigated the relationships of plasma sex hormones (free testosterone; free T, estradiol; E2 dehydroepiandrosterone-sulfate; DHEA-S) and sex hormone-binding globulin (SHBG) levels to lipid and glucose metabolism cross-sectionally in 212 apparently healthy men aged from 18 to 59 years. A multiple linear regression analysis for lipid and glucose parameters with age, body mass index (BMI), percent body fat (%fat), waist to hip ratio (WHR), estimated maximal oxygen uptake (VO2max), alcohol and cigarette consumption, sex hormones, and SHBG, respectively, as independent variables, was performed. DHEA-S was indicated as one of the independent predictors of both high density lipoprotein cholesterol (HDL-C), with a positive relation, and of triglyceride and total cholesterol/HDL-C ratio, with a negative relation, while SHBG was one of the predictors of both HDL-C, with a positive relation, and of fasting insulin, with a negative relation. The E2 level was found to be negatively related to both low density lipoprotein cholesterol and fasting blood glucose. These findings thus suggest that the higher levels of SHBG, DHEA-S and E2 within physiological ranges in healthy men may partially help to maintain a desirable profile of the plasma lipid and glucose metabolism.

The effect of endurance training on the relationships between sex hormone binding globulin, high density lipoprotein cholesterol, apoprotein A1 and physical fitness in pre-menopausal women with mild obesity

The purpose of the present study was to investigate the relationships of change in high density lipoprotein cholesterol (HDL-C) with changes in sex hormone binding globulin (SHBG), physical fitness and spontaneous dietary intake before and after endurance training. Ten pre-menopausal obese women (32 to 49 years) who had never smoked or regularly drunk alcohol participated in this study. Physical training at an intensity of lactate threshold was performed for six months at a frequency of three times per week for 60 minutes using a cycle ergometer. Together with a reduction in body weight (-4.1 kg; P < 0.05) and with increases in maximal oxygen uptake (VO2max = +3.4 ml/kg/min or +0.09 l/min; P < 0.05), the training induced some changes in both plasma lipid and lipoprotein. Although the total cholesterol (total-C), triglyceride, HDL2-C and apoprotein A1 (Apo A1) levels did not change, significant increases in HDL-C and HDL3-C, and significant reductions in Apo B, total-C/HDL-C ratio and fasting insulin concentrations were found after training. SHBG levels tended to increase after endurance training, but the changes were not significant. No alteration was observed in spontaneous dietary intake after training. A significant correlation (r = 0.648) was observed between the change in VO2 max(l/min) and the change in SHBG. In addition, changes in both VO2 max(l/min) and SHBG were significantly associated with changes in HDL-C, HDL2-C and Apo A1. The changes in dietary intake did not correlate with the changes in SHBG, VO2max, HDL-C, HDL2-C and Apo A1.(ABSTRACT TRUNCATED AT 250 WORDS)

[The relationships of sex hormone binding globulin (SHBG) with high density lipoprotein cholesterol and fasting insulin in healthy men]

The relationships of sex hormone binding globulin (SHBG) with high density lipoprotein cholesterol (HDL-C) and fasting insulin (IRI) were investigated in healthy employed men (n = 235). In simple correlation analysis, the SHBG was positively related to total cholesterol and HDL-C, and negatively related to IRI. There were no relationships among SHBG, triglyceride and fasting blood glucose. In multiple linear regression analysis, SHBG was one of determinant of HDL-C, but not IRI. From these results, it was suggested that SHBG was one of the determinants of HDL-C level in healthy men.

Laryngeal epithelial changes on effects of smoking and drinking

The human larynx is essential not only for speech, but also for swallowing and respiration. Its tissues are affected by the presence of alcohol and cigarette smoke. In this report we present our findings on the effects of smoking and drinking on histological changes in laryngeal tissue. The larynges studied were those of autopsy patients: cases with damaged tissue were excluded. We studied the larynges of 84 men (non-smoker and non-drinker, 22 cases; smoker and drinker, 62 cases) and 48 women (non-smoker and non-drinker, 40 cases; smoker and drinker, 8 cases) between the ages of 12 and 88. The squamous metaplasia of laryngeal epithelium was examined using the gross staining method (Pyronin Y) of STELL et al. (J. Laryngeal. Otol. 86: 589-594, 1972). The squamous epithelium is unstained, whereas the respiratory epithelium is a brilliant red. The area of metaplasia in the supraglottic region increased with aging, tobacco and alcohol consumption. Microscopic changes of the laryngeal epithelium were investigated using the hematoxylin-eosin staining method. The thickness of epithelium of the supraglottic region and vocal cord increased with age. There is a significant difference in the thickness of the epithelium of the supraglottic region and vocal cords of smoking and drinking patients, when compared with the same tissues of non-smokers and non-drinkers. Furthermore, there is a significant difference in those tissues of the supraglottic region of heavy smokers, when compared with light smokers, but no significant difference when compared with drinkers. However, there is no significant difference in the thickness of vocal cord tissues when comparing light smokers and drinkers on the one hand, and heavy smokers and drinkers on the other.