Bioimpedance phase angle indicates catabolism in Type 2 diabetes.

AIMS: Body cell mass is directly proportional to the bioimpedance phase-angle which is an indicator of the amount of electrical charge that cell membranes can hold and is an index of cellular health and function. To evaluate whether the bioimpedance phase angle is relevant for indicating catabolism in people with diabetes and whether it discriminates between people with diabetes receiving different types of therapy. METHODS: A cross-sectional study was performed in 182 people with Type 2 diabetes and 107 age- and BMI-matched control subjects. The phase angle was measured at 5, 50 and 100 kHz using multifrequency bioimpedance analysis. The phase angles were compared among different diabetes therapy groups (untreated patients with diabetes, patients receiving oral antidiabetic drugs and patients receiving insulin therapy). RESULTS: The phase angle at 100 kHz strongly correlated with total body potassium (r = 0.70, P = 0.001), and was therefore a good indicator of body cell mass. The phase angle at 100 kHz discriminated more strongly between patients with Type 2 diabetes and control subjects than did the phase angle at 50 kHz. Compared with control subjects, patients with Type 2 diabetes had a smaller phase angle at 100 kHz (men: 5.2° vs. 4.5°, P < 0.0001; women: 4.8° vs. 4.2°, P < 0.0001) and a smaller phase angle at 50 kHz (men: 5.9° vs. 5.3°, P < 0.0001; women: 5.4° vs. 4.8°, P = 0.0001), but a larger phase angle at 5 kHz (men: 2.0° vs. 2.6°, P = 0.0001; women: 2.3° vs. 3.0°, P = 0.00001). Phase angle ratios better discriminated between patients and control subjects than phase angles alone (phase angle at 5 kHz/ phase angle at 50 kHz ratio, P = 1.51 × 10(-16) ; phase angle at 5kHz/phase angle at 100 kHz ratio, P = 2.13 × 10(-15) ). No differences were found among phase angles in the different therapy groups. In patients with diabetes, the phase angle at 50 kHz and the phase angle at 100 kHz correlated inversely with duration of disease (men: P = 0.026, P = 0.016; women: only phase angle at 100 kHz, P = 0.003) and with HbA1c concentration (men: P = 0.010, P = 0.001; women: P = 0.007, P = 0.043). CONCLUSIONS: The phase angle at 100 kHz is a promising measurement for assessing catabolic state in people with diabetes.

Reduced DNASE1 gene expression in thyroid autoimmunity.

The enzyme DNASE1 plays an important role in the hydrolysis of double-stranded DNA and might be related to autoimmunity. Therefore, the authors hypothesized that patients with autoimmune thyroid disease show a reduced expression of the DNASE1 gene. DNASE1 mRNA was quantitatively analyzed in 20 patients (10 with Hashimoto's thyroiditis and 10 with Graves' disease) and 20 age- and sex-matched healthy controls by real-time reverse transcription PCR in a lightcycler using SYBR-Green-format. For relative quantification, the mRNA ratio of the DNASE1 gene to the house keeping gene ß2-MICROGLOBULIN was used. The house keeping gene was proved not to be regulated by autoimmune thyroid disease. The interassay coefficient of variation for patients and controls was 22.2% and 15.6%, respectively, suggesting good reproducibility of measurements. The mean expression of the DNASE1 mRNA in patients was 0.52±0.22 (range 0.18-0.99) and in controls 0.95±0.22 (0.66-1.43). The expression level of the DNASE1 gene was strongly decreased in patients, amounting only 54.7% of that in controls (p<0.001). The lowered expression level in patients was not related to age or sex. This study demonstrated for the first time a downregulation of the DNASE1 mRNA expression in patients with autoimmune thyroid disease. This might result in degrading less DNA from dying cells, thereby promoting the development of thyroid autoimmunity.

Diagnosis of pericardial effusion with a new generation hand-carried ultrasound device in cardiothoracic intensive care unit patients.

BACKGROUND: Technological advances introduced hand-carried ultrasound (HCU) imagers in daily clinical workflow providing several benefits such as fast bedside availability and prompt diagnosis. PURPOSE: To evaluate the diagnostic yield of a latest generation HCU imager compared to contrast-enhanced multidetector computed tomography (MDCT) for the detection of pericardial effusion (PE) in cardiothoracic intensive care unit (ICU) patients. MATERIAL AND METHODS: Thirty-six patients from a cardiothoracic ICU were enrolled to this study irrespective of their underlying disease. All patients were examined with a new generation HCU for the presence of PE. Definite diagnosis of PE was based on findings of MDCT as standard of reference. Statistical analysis was performed using PASW 18. RESULTS: PE was identified in 20 patients by MDCT (prevalence 56%). The HCU examination was carried out technically successfully in all patients. Sensitivity, specificity, positive and negative predictive value of HCU for the diagnosis of PE were 75%, 88%, 88%, and 74%, respectively. CONCLUSION: HCU provides rapid, practical, reliable, and cost-effective diagnosis of PE in patients on cardiothoracic ICU.

Body circumferences are predictors of weight adjusted resting energy expenditure in older people.

OBJECTIVE: To evaluate predictors of resting energy expenditure (REE) in older people which are more comfortable for them than indirect calorimetry and which are suitable for field studies. DESIGN: Cross-sectional study. SETTING: Department of Human Biology, Kiel University. PARTICIPANTS: 100 (51 males, 49 females) healthy independently-living normal-weight (BMI, males 26.0±2.67 kg/m², females 25.0±3.29 kg/m²) Germans, aged 60-83 years. MEASUREMENTS: REE, body composition, anthropometry, peak expiratory flow rate (PEF), and physical activity level were determined using indirect calorimetry, bioimpedance analysis, anthropometrics, peak-flow-meter, and standardized questionnaire, respectively. Stepwise linear multiple regression analysis was performed with REE or weight adjusted REE as dependent variables. Independent variables were body height, weight, body mass index (BMI), waist circumference, abdomen circumference, hip circumference, waist-to-hip ratio (WHR), lean body mass (LBM), PEF, and physical activity level. RESULTS: The only significant predictor of REE was LBM in males and BMI in females. Trunk circumferences emerged as strong predictors of weight adjusted REE. Abdomen circumference and hip circumference explained in males and females 69% and 70% of variation in adjusted REE, respectively. Weaker predictors were LBM in males (R² increased from 0.69 to 0.80) as well as body height and BMI in females (R² increased from 0.70 to 0.91). Waist circumference, WHR, physical activity level, and PEF were no significant determinants of adjusted REE. CONCLUSION: These findings demonstrate that trunk circumferences, but not WHR, are very strong predictors of weight adjusted REE in non-geriatric older people. This implies that the sex-specific use of abdomen or hip circumference in combination with LBM or body height and BMI seems to be well sufficient to predict weight adjusted REE in the aged. These measures might also be of clinical relevance, because they are more comfortable for older sick people than indirect calorimetry. Further studies are needed to test the applicability of the prediction equations to frail older populations.

Increased familial clustering of autoimmune thyroid diseases.

Data regarding familial prevalence and recurrence risk ratio of autoimmune thyroid diseases (AITD) in Germany are lacking. The data from 179 German families of AITD patients encompassing 1 229 relatives were collected using standardized clinical and laboratory diagnostic criteria. Of this large collective, 86 AITD index cases with their 139 children and 106 AITD index cases with their 157 siblings were included. The familial prevalence was estimated by the recurrence risk ratio. This quotient indicates whether first degree relatives display an increased risk for developing AITD, compared with the general population. AITD were present in 14% of children and 15% of siblings of patients with AITD. Female gender was frequently affected in both offspring (female:male ratio=3:1) and siblings (11:1). Daughters (19%) and sisters (24%) were more frequently affected than sons (7%) and brothers (3%). The risk for developing AITD was 16-fold and 15-fold increased in children and siblings, respectively, of patients with AITD. In particular, children and siblings of index cases with Hashimoto's thyroiditis had a 32-fold and 21-fold increased risk, respectively, for developing immunthyroiditis. In comparison, the risk for developing Graves' disease was enhanced 7-fold in both children and siblings. The high prevalence of AITD in first degree, foremost female, relatives of patients with AITD demonstrates the importance of family history for developing AITD. Hence, regular screening of children and siblings of patients with AITD for presence of immunethyroiditis is recommended.

CTLA-4 CT60 polymorphism in thyroid and polyglandular autoimmunity.

Autoimmune thyroid diseases (AITDs) frequently occur together with other endocrine autoimmune conditions, denominated as polyglandular autoimmunity (PGA). The cytotoxic T-lymphocyte antigen 4 (CTLA-4) gene was recently associated with AITD and PGA, and the CTLA-4 protein is a strong inhibitor of T-cells.The tumor necrosis factor alpha (TNF-alpha) is a proinflammatory cytokine. This study aimed to analyze the association of the CTLA-4 CT60 and TNF-alpha-863 polymorphisms with PGA. Homogeneous groups of 70 patients with AITD, 70 with type 1 diabetes (T1D), 70 with both AITD and T1D (PGA), and 100 healthy controls were genotyped for the CTLA-4 CT60 and TNF-alpha-863 polymorphisms by minisequencing on an ABI PRISM-3100 genetic analyzer. The CT60 G/G genotype was significantly more common in patients with PGA than in healthy controls (48.6 % vs. 32.0 % , OR = 2.01, 95 % CI = 1.07-3.77, p = 0.038). The CT60 allele frequencies differed as well between PGA patients and controls, with the predisposing G allele being increased in PGA (OR = 1.63, 95 % CI = 1.03-2.55, p = 0.042). Patients with PGA did not differ from those with AITD (p = 0.602) or T1D(p = 0.362). For TNF-alpha-863, carriers of the minor A allele occurred more frequently in the T1D group than in controls (47.1 % vs. 33 % , OR = 1.81, 95 % CI = 0.97-3.39, p = 0.079), but no differences in allele or genotype distribution were noted between PGA patients and controls (p = 0.886 and 0.389, respectively). In conclusion the CTLA-4 CT60 polymorphism is associated with PGA.

Impaired deoxyribonuclease activity in monoglandular and polyglandular autoimmunity.

OBJECTIVE: The enzyme desoxyribonuclease (DNase) degrades DNA during early apoptosis. Impaired DNase activity might increase susceptibility to autoimmune diseases. This study examined for the first time DNase activity in endocrine autoimmunity. METHODS: Included were 112 patients with monoglandular (MGA) or polyglandular autoimmunity (PGA), their 93 healthy relatives, and 41 healthy controls. Serum DNase activity was quantified with a solid phase enzyme immunometric assay comprising degradation of the specific immobilized DNase substrate, formation of enzyme conjugate complexes using horseradish peroxidase conjugate solution, and enzymatic colour reaction. RESULTS: The Bland-Altman plot of the interassay differences suggested good reproducibility (n=96). Compared to healthy controls (median 9.8, range 5.2-16.7 ng/ml), DNase activity was markedly lowered in patients with endocrine autoimmunity (5.8, 2.6-26.2 ng/ml; p<0.0001). Corresponding values in the following MGA, PGA, and relatives groups were 4.8 (2.8-19.0) ng/ml, 7.9 (2.6-26.2) ng/ml, and 8.4 (1.5-19.0) ng/ml, respectively. When MGA patients were splitted up by disease, patients with type 1 diabetes had the lowest DNase activity (3.6, 3.2-3.9 ng/ml) which positively correlated with HbA1c in females (r=0.486, p=0.041). Pathological reduction of DNase activity (below 5 ng/ml) was noted in 54%, 31%, 24%, and 0% of MGA, PGA, relatives, and controls, respectively. Anti-ds-DNA and anti-nucleosome antibodies were negative in the patients with MGA and PGA. CONCLUSIONS: These findings indicate the potential relevance of DNase activity in patients with monoglandular and polyglandular autoimmunity and their clinically healthy relatives. The impaired DNase activity might reduce removal of circulating self- or pathogen-derived DNA thereby favoring autoimmune mechanisms by Toll-like receptor 9 co-activation.

Alpha-fodrin as a putative autoantigen in Graves' ophthalmopathy.

Alpha-fodrin, an intracellular organ-specific cytoskeleton protein is a recently identified autoantigen associated with Sicca- and Sjogren's syndrome (SS). SS frequently affects patients with Graves' ophthalmopathy (GO). We have therefore cloned and expressed the human recombinant 120-kDa fodrin-fragment. A sequential purification procedure was applied to isolate the recombinant protein. Using sera from patients with SS, the antigenicity of the purified fodrin fragment was demonstrated by immunoblotting. Sera from 144 patients with GO and 1200 blood donors were screened for the presence of anti-alpha-fodrin IgA and IgG antibodies by a newly developed ELISA using the human alpha-fodrin fragment as an autoantigen. In contrast to controls (<1% IgA only, P < 0.001) and to subjects with various autoimmune diseases (P < 0.001), alpha-fodrin antibodies were detected in 22% of patients with GO (n = 32). IgA and IgG antibodies were present in 21 (15%) and 14 (10%) GO subjects, respectively. A total of 45 patients with GO (31%) had at least one fodrin- or SS-antibody. GO patients with SS showed SS- and high titres of alpha-fodrin-antibodies. In GO patients, fodrin antibodies correlated with TPO- (P < 0.05) and SS-A (P = 0.002) antibodies. Thus, for the first time, antibodies reactive with fodrin are reported in patients with GO.

Cicloral versus neoral: a bioequivalence study in healthy volunteers on the influence of a fat-rich meal on the bioavailability of cicloral.

The bioavailability of cyclosporine a (CyA) was assessed in 2 cross-over studies with 12 healthy male volunteers each. Study A compared the bioavailability of Cicloral (test) with the microemulsion Neoral (reference) in the fasting state. Study B examined the influence of a fat-rich meal composed according to the Food and Drug Administration (FDA) recommendations on the bioavailability of Cicloral. Each volunteer received a single dose of 200 mg CyA in each period. Whole blood CyA concentrations were determined using HPLC up to 48 hours after drug administration. The pharmacokinetic parameters were determined using standard noncompartmental methods. The mean bioavailability of Cicloral compared with Neoral amounted to 83% (AUC) and 78% (Cmax), respectively. When administered after a fat-rich meal, the bioavailability of Cicloral was 121% (AUC) and 132% (Cmax) compared with fasting administration. Time to Cmax was 1.3 to 1.4 hours for both medications and modes of administration. Bioequivalence could not be proven either between Cicloral and Neoral, or between Cicloral fasting versus after a fat-rich meal. We conclude that the lower bioavailability and the influence of food on the bioavailability of Cicloral must be taken into account when switching from Neoral to the generic formulation.

Metabolic and psychosocial effects of minimal invasive gastric banding for morbid obesity.

Obesity is considered a primary risk factor for cardiovascular disease and related mortality. The current study aimed to investigate the efficacy of minimal invasive gastric banding (GB) surgery for reducing caloric intake in morbid obesity, and to analyze the effects of weight loss on body composition and metabolic and psychosocial outcomes. Twenty-six adult severely obese patients (mean body mass index [BMI], 48.1 kg/m(2); range, 42 to 56) underwent adjustable silicone laparoscopic GB. Nine additional obese patients who declined surgery were treated with metformin (2 g daily) and served as a small additional group (BMI, 50.5 kg/m(2); range, 41 to 68). Presurgery and 17 +/- 2.2 months postoperatively, body composition (fat mass [FM], lean body mass [LBM], body water) and serum parameters (lipids, glucose, thyrotropin-stimulating hormone [TSH]) were determined. Quality of life (QoL) was evaluated by a standardized self-rating questionnaire (Short Form-36 [SF-36]), and supplemented by measures of physical complaints and psychological distress. After GB, weight loss was 21 +/- 14.9 kg (14%, P <.001). It was associated with a decrease in FM by 14 +/- 8.6 kg (18%, P <.001), LBM by 4 +/- 2.7 kg (5%, P <.001), body water by 4 +/- 3.4 L (7%, P <.01), systolic blood pressure by 16 +/- 26.3 mm Hg (10%, P <.05), total cholesterol by 0.69 +/- 1.29 mmol/L (12%, P <.05), and low-density lipoprotein cholesterol (LDL-C) by 0.38 +/- 0.39 mmol/L (10%, P <.05). Highly significant interactions between surgery and time were noted for weight (P <.005), BMI (P <.005), and FM (P <.007, analysis of variance [ANOVA]). Preoperatively, 14 of 26 patients (54%) had high fasting blood sugar levels (type 2 diabetics) and 11 (42%) had impaired glucose tolerance, whereas postoperatively, for baseline glucose levels a trend to decrease was noted. Neither malabsorption nor anemia was observed. QoL improved after GB; in particular, physical functioning and well being increased (P <.01), and somatic complaints (eg, dyspnea and heart complaints, pain in legs and arms) markedly decreased (P =.008). In the metformin group, neither relevant weight loss nor a significant decrease of biochemical values was observed. Minimal invasive GB is a successful therapeutic tool for reducing FM in morbidly obese patients. Weight loss resulted in improved metabolic parameters, suggesting a lowered atherogenic risk.

Diagnosis of porcine proliferative enteropathy: detection of Lawsonia intracellularis by pathological examinations, polymerase chain reaction and cell culture inoculation.

A total of 21 pigs aged 7-17 weeks with clinical symptoms suggestive for Porcine Proliferative Enteropathy were examined for Lawsonia intracellularis by analysing the following parameters: (i) intestinal gross and histological lesions, (ii) presence of comma-shaped bacteria in enterocytes by Warthin-Starry and a modified Ziehl-Neelsen stain, (iii) PCR amplification of L. intracellularis DNA from intestinal mucosa by using two oligonucleotide primer pairs targeting a 255-bp DNA fragment of the 16S rDNA-gene and a 319-bp DNA fragment of the L. intracellularis chromosome. Specificity of PCR reactions was confirmed by using DNA extracted from the L. intracellularis reference strain N343 (ATCC 55672) as well as by DNA sequence comparisons of PCR amplification products with data bank entries. Intestinal gross lesion indicative for PPE were observed in 20 pigs (95.2%). For all 21 pigs, the L. intracellularis aetiology was confirmed by histological as well as bacterioscopical examinations. Specific PCR amplification products were obtained from 20 pigs (95.2%). Taking PCR positivity as the definite criterion, L. intracellularis was diagnosed in 20 pigs from 11 herds in seven Swiss cantons (Argovia, Berne, Fribourg, Grisons, Lucerne, Schwyz, Thurgovia). To grow L. intracellularisin vitro, the cell culture method of Lawson et al. (J. Clin. Microbiol. 1993: 31, 1136-1142) was adopted. Inocula prepared from heavily infected fresh and frozen ileal mucosa of 15 pigs were cultured in rat enterocytic IEC-18 cells (ATCC CRL 1589). Six cell culture passages of 10 days each were completed. The reference strain N343 was examined for cultivability, accordingly. Except for occasional specific PCR amplifications from cell cultures up to the second passage, any indications for growth of L. intracellularis in IEC-18 cells were not found.

New equations for estimating body cell mass from bioimpedance parallel models in healthy older Germans.

The objectives of this study were to assess for elderly Germans the validity of existing equations for predicting body cell mass (BCM) and to develop from single- and multifrequency bioimpedance (SFBIA, MFBIA) models new prediction equations. In a data-splitting approach, validation and cross-validation were performed in 160 healthy elderly (60- to 90-yr) subjects. BCM was determined using a tetrapolar bioimpedance analyzer (800 microA; 4 fixed frequencies: 1, 5, 50, and 100 kHz; electrodes placed to hand, wrist, ankle, and foot) and whole body (40)K counting as a reference method. New prediction equations were derived by multiple stepwise regression analysis. The Bland-Altman procedure was used for methods comparison. Relative to whole body counting, the manufacturer's equation overestimated BCM by 9% in men (P < 0.0001, paired t-test) and 4% in women (P = 0.002). Compared with the manufacturer's equation, the newly derived equations (r = 0.92, RMSE = 6-9%) improved accuracy (pure error = 13 vs. 7-8%) and reduced bias and limits of agreement. SFBIA and MFBIA equations did not differ in precision or accuracy. We conclude that the newly derived equations improved BCM estimates in the elderly compared with existing equations. There was no advantage of MFBIA over SFBIA equations.

Characterization of a late entry event in the replication cycle of human immunodeficiency virus type 2.

Certain human cell lines and primary macrophage cultures are restricted to infection by some primary isolates of human immunodeficiency virus type 2 (HIV-2), although early steps of the viral life cycle such as fusion at the plasma membrane and reverse transcription are fully supported. The late postintegration events, transcription, translation, assembly, budding, and maturation into infectious virions are functional in restrictive cells. Apart from primary macrophages, the restrictive cell types are actively dividing, and nuclear import of preintegration complexes (PICs) is not required for infection. We therefore postulate that the PICs are trapped in a cellular compartment, preventing subsequent steps in the replication cycle that lead to integration of the provirus. To test this we showed that HIV-2 particles pseudotyped with vesicular stomatitis virus envelope G protein, which delivers HIV into an endocytic compartment, could overcome the block to infection. We suggest that delivery of the viral core into an appropriate cellular compartment is a critical step during the entry process of HIV.

Age-related decline in body cell mass in elderly men and women, determined by a noninvasive nuclear technique: effects of physical activity and dietary potassium intake.

The body cell mass (BCM) represents the actively metabolizing cellular components of the human body. In this study, the hypothesis was tested that physical activity and a sufficient dietary intake of potassium attenuate the age-related decline in BCM in the elderly. Cross-sectional data were collected in 82 male and 79 female non-institutionalized elderly (60-90 years) from Mainz, Germany, and were analyzed by age groups. BCM was calculated from total body potassium, measured by whole-body counting of naturally occurring 40K. Physical activity level (PAL) was assessed by a standardized questionnaire. Dietary intake of potassium (DIP) was estimated from a 7-day food diary. The results showed the following trends: (1) BCM decreased continuously from age 60 to 90 years by 11.2% (men) and 7.0% (women). BCM was inversely correlated with age in both sexes (men, P < 0.001; women, P < 0.05), but significant age group differences only existed for men (P < 0.01, one-way analysis-of-variance). Women had less BCM than men in all age groups (P < 0.001, t tests). (2) Correlation analyses demonstrated that in both sexes PAL declined with advancing age (P < 0.05), whereas DIP did not change significantly with age. (3) In both sexes, BCM showed a strong positive correlation with PAL (P < 0.001), but did not correlate significantly with DIP. Multiple linear regression analysis (independent variables were PAL, DIP, age, height, weight) demonstrated that PAL, age, and height explained 45% of the variability in BCM in men. In women, PAL was the only significant predictor of BCM, explaining 23% of the variance. The study supports the hypothesis that the level of physical activity is associated with the decline of BCM in the elderly.

Changing colour preferences with ageing: a comparative study on younger and older native Germans aged 19-90 years.

BACKGROUND: Previous studies have shown that colour preferences change from early childhood to adulthood. OBJECTIVE: The main objective of this study was to assess whether colour preferences undergo further changes during adult life. METHODS: Cross-sectional data on colour preferences were collected in 842 adults (aged 19-90 years) living in Mainz, Germany. The sample was split by age into younger (183 men, 232 women) and older (157 men, 270 women) adults. The subgroups were compared for their most and least preferred colours that they had chosen by name out of four given colours (blue, green, red, yellow). Differences in the pattern of frequencies between sexes and age groups were assessed for statistical significance using chi-square analyses. RESULTS: Both age groups and both sexes chose blue as most preferred colour and yellow as least preferred one; green and red fluctuated in the middle position of the rank order of preferences. All frequency distributions departed significantly from chance (p < 0.001). In both younger and older adults, significant sex differences did not exist for the ranking of the most preferred colours (p > 0.2), but were evident in the ranking of the least preferred colours (p < 0.01); men stated more often yellow and less often red as least preferred than women did. Age group differences in colour preferences were highly significant. With advancing age, the preference for blue decreased steadily, whereas the popularity of green and red increased (p < 0.001). CONCLUSIONS: The results suggest that colour preferences change during the course of the adult life span. These changes seem to be a reversal of the trend reported in the literature for children. Changed colour preferences in the aged might be attributed to alterations in colour discrimination and visual imagery, the yellowing of the crystalline lens, and the decreased function of the blue cone mechanism with ageing.

Comparison of soft tissue body composition in postmenopausal women with or without hormone replacement therapy considering the influence of reproductive history and lifestyle.

OBJECTIVES: To examine long-term effects of at least 5 years' conventional hormone replacement therapy (HRT), reproductive history and lifestyle on fat mass and muscle mass in postmenopausal women. RESEARCH DESIGN AND METHODS: A cross-sectional retrospective approach was used, including 64 healthy women (56-69 years, mean age 63.4 years). Hormone users were compared with age-matched non-users with respect to (a) type of HRT used (oestrogen vs oestrogen plus gestagen vs no hormones), (b) categories of oestrogens used (oestradiol-based oestrogens vs conjugated equine oestrogens vs no oestrogens) and (c) categories of gestagens used (testosterone derivatives vs progesterone derivatives vs no gestagens). Data on hormone use, reproductive history (age at menarche, age at menopause, number of years postmenopausal, number of children) and lifestyle (physical activity level, alcohol consumption, smoking habits) were collected by questionnaires. Body composition was analysed by multiple-frequency bioelectrical impedance analysis, estimating fat mass, fat-free mass and body cell mass as absolute values (FM, FFM, BCM, respectively) and percentages of body weight (%FM, %FFM, %BCM). RESULTS: Analysis of covariance, adjusting body composition variables for body mass index, showed that (a) unopposed oestrogen users, oestrogen plus gestagen users and non-users did not differ significantly in body composition variables, (b) users of oestradiol-based oestrogens had significantly more BCM than oestrogen abstainers (p < 0.05), (c) users of testosterone-based gestagens had more BCM than gestagen abstainers (p = 0.05). Stepwise multiple regression analyses, including HRT-related, reproductive and lifestyle variables, indicated that the duration of HRT (p < 0.05) and physical activity level (p = 0.01) were significant positive predictors of %BCM, whereas the number of children significantly positively predicted FM and %FM (each p < 0.05). No significant associations between fat-free mass and HRT were found. CONCLUSIONS: The results suggest that conventional doses of oestrogens and gestagens used in HRT might be a factor in preserving muscle mass after long-term administration. It is recommended that BCM is used instead of FFM as an indicator of muscle mass. Studies relating muscle mass to HRT in postmenopausal women should consider physical activity as a possible confounding variable.

Membrane-anchored peptide inhibits human immunodeficiency virus entry.

Peptides derived from the heptad repeats of human immunodeficiency virus (HIV) gp41 envelope glycoprotein, such as T20, can efficiently inhibit HIV type 1 (HIV-1) entry. In this study, replication of HIV-1 was inhibited more than 100-fold in a T-helper cell line transduced with a retrovirus vector expressing membrane-anchored T20 on the cell surface. Inhibition was independent of coreceptor usage.

Loss of N-linked glycans in the V3-loop region of gp120 is correlated to an enhanced infectivity of HIV-1.

We describe mutants of human immunodeficiency virus type-1 (HIV-1) strain NL4-3, which are lacking the thirteenth, fifteenth, or seventeenth sites for N-linked glycosylation (g13, g15, g17) of the envelope protein gp120. All three sites are located within the hypervariable V3 loop region of gp120. Those mutants lacking carbohydrates g15 or combinations of g15/g17 showed markedly higher infectivity for GHOST cells (human osteosarcoma cells) expressing CXCR4 (GHOST-X4), compared to the fully glycosylated NL4-3 wild type virus. In addition, these mutants could also infect cells which exhibits low background expression of CXCR4, corresponding to <10% of that observed for GHOST-X4 cells. In addition to the enhanced infectivity observed, mutants lacking g15 and g17 showed increased resistance to inhibition by SDF-1, the natural ligand of CXCR4. Thus, loss of the oligosaccharides g15 and g17 in the V3 region of gp120 markedly influences CXCR4-specific infection.

A recombinant virus assay using full-length envelope sequences to detect changes in HIV-1 co-receptor usage.

The clinical management of HIV-1 infection has benefited enormously from molecular characterization of drug resistance as well as determination of the viral phenotype in vitro. HIV-1 infected individuals on HAART are currently monitored for the development of drug resistance variants allowing clinicians to redesign drug regimens. An understanding of the molecular basis of the evolution of drug resistance in vivo allows the improvement of the drugs as well as in vitro evaluation of new antiviral compounds alone or in combination with those currently approved. New findings suggest that viral envelopes could be a target to inhibit infection and replication. Therefore the generation of a recombinant virus assay (RVA) to allow the phenotypic determination of drug resistance against entry inhibitors (EI) is anticipated. We constructed an env-deleted clone of HIV-1 using the molecular clone NL-4.3. PCR amplified complete envelope genes (NL-4.3, BaL, primary envelope-genes) were ligated in vitro with a deletion clone (pNL-deltaK) and PM1-cells, supporting the replication of R5- and X4-tropic viruses, were transfected. Determination of co-receptor usage of the harvested recombinant virus-swarm revealed no difference compared to the molecular clones derived individually from three different patients. These results clearly show that an envelope-based RVA is practicable to monitor HIV-co-receptor usage at a given time point. Furthermore, this assay will allow to monitor resistance development against existing and future entry inhibitors and will aid to improve the management of HIV-therapy.

Coreceptor requirements of primary HIV type 1 group O isolates from Cameroon.

HIV-1 group O has its epicenter in Cameroon and neighboring countries and is responsible for 3 to 5% of all HIV infections in this region. It is believed that HIV-1 group O was introduced into the human population by a separate cross-species transmission, occurring independently of the HIV-1 (group M and group N) and HIV-2 transmissions. We have studied the coreceptor requirements of 12 primary HIV-1 O-type isolates from individuals with different clinical symptoms. Only 2 of these 12 viruses showed a syncytium-inducing phenotype after infection of primary peripheral blood mononuclear cells (PBMCs) and were infectious for the T cell line C8166. These isolates used CXCR4 as a coreceptor for entry, whereas the remaining isolates used only CCR5 efficiently. One isolate was able to use BOB and CCR8 as coreceptors in addition to CXCR4. All group O isolates tested were efficiently inhibited by SDF-1 or RANTES, the natural ligands of CXCR4 and CCR5, respectively. These results indicate that CXCR4 and CCR5 are the principal coreceptors for HIV-1 O-type viruses. Most of the HIV-1 group O isolates studied were derived from patients at later stages of the disease. Although HIV-1 group O and group M infections do not differ in their pathogenesis, the studied isolates did not evolve to use a broad range of coreceptors as described for HIV-1 group M and HIV-2.