Caloric restriction increases serum testosterone concentrations in obese male subjects by two distinct mechanisms.

The concentration of serum testosterone is mainly regulated by the testicular function, which is under control of the central hypothalamic-pituitary-gonadal axis. A certain amount of testosterone is converted into ß-estradiol by adipose tissue. Obesity in men is often associated with decreased androgen levels. The aim of the present study was to examine the effect of caloric restriction on serum testosterone levels in obese men. Dietary intervention study was performed with a very low calorie diet (800 kcal/d) for 12 weeks. Thirteen obese human male subjects (median body mass index: 42.7 kg/m2) were included. Body composition was assessed by impedance analysis. Insulin sensitivity was estimated by leptin-to-adiponectin ratio (LAR). Testosterone (T), ß-estradiol, albumin, sex hormone-binding globulin (SHBG), LH, and FSH serum concentrations were measured by enzyme immunoassays. Statistical analysis was performed on baseline and values after 3 months. Caloric restriction significantly increased total testosterone (6.97 nmol/l to 13.21 nmol/l; p=0.001) and SHBG (22.11 nmol/l to 42.12 nmol/l; p=0.001) concentrations in serum. This is caused by a significant improvement of the testicular function (LH/T: 0.36-0.20; p=0.005) and a significant reduction of the T/ß-estradiol conversion rate (73.59-104.29; p=0.003). There was a significant negative correlation of improvement of testicular function and LAR (rs=-0.683 (p=0.042)). In obese men caloric restriction significantly increases the serum testosterone concentration. This is achieved by 2 distinct mechanisms, that is, improvement of testicular function and reduced conversion of testosterone to ß-estradiol by aromatase activity of the adipose tissue.

Calcitonin screening in patients with thyroid nodules. Diagnostic value.

AIM: The positive predictive value (PPV) of a slightly elevated basal calcitonin (CT) for the diagnosis of medullary thyroid cancer (MTC) is still under debate. PATIENTS, METHODS: A total of 11270 patients with thyroid nodules underwent calcitonin screening. Patients with known elevation of CT, renal insufficiency, bacterial infection, alcohol abuse, proton-pump inhibitor therapy or autoimmune thyroid disease were excluded from further analysis. Serum CT was determined by the solid-phase, enzyme-labeled, two-site chemiluminescent immunoassay Immulite 2000. If possible, a pentagastrin test was done to differentiate cases of hypercalcitoninaemia. RESULTS: Hypercalcitoninsemia was found in 32 patients. 20 patients underwent surgery. In 10 patients a MTC was found. The PPV of hypercalcitoninaemia for MTC was 31%. The PPV increased to 50% for those patients who underwent surgery (10/20). A subgroup of 26 patients presented with basal CT between 13 and 50 pg/ml, 14 of them underwent surgery, in 4 cases evidence of MTC was revealed. This resulted in a PPV of 15% (4/26), although the value increased to 28% when only surgically treated patients were considered (4/14). CONCLUSION: Taking all clinical data into account, calcitonin screening has an acceptable PPV for medullary thyroid cancer in patients with thyroid nodules. Therefore, we recommend calcitonin screening in centers for thyroid disorders.

Identification and quantification of high fluorescence-stained lymphocytes as antibody synthesizing/secreting cells using the automated routine hematology analyzer XE-2100.

OBJECTIVES: The aim of this study was to classify and quantify the high fluorescence lymphocytes area (HFL-count) from the SYSMEX XE-2100 leucocyte differential channel as antibody-synthesizing or -secreting cells (ASC, plasma cells or lymphoplasmacytoid cells) in reactive diseases. To unequivocally identify the HFL cells, all possibly eligible cell populations have been investigated: activated B-lymphocytes, activated T-lymphocytes, large granular lymphocytes (LGL), activated monocytes, and immature granulocytes. METHODS: In total, 85 patients were analyzed on the XE-2100 and compared with the automated image analysis system Cellavision Diffmaster 96 based on artificial neural network and immunophenotyping method with the BD FACSCalibur. RESULTS: Reproducibility tests for HFL demonstrated a mean coefficient of variation of 13.9% for very low results and 1.5% for high results. The linearity data showed a good correlation (R(2) = 0.99) between expected and measured HFL. The comparison with possibly eligible cell populations showed no significant correlation between activated monocytes and immature granulocytes, with most immature granulocytes (promyelocyte I or II), natural killer cells or LGLs, activated T-lymphocytes, and sub-T-lymphocytes populations. However, for activated B-lymphocytes an excellent significant correlation with the peripheral blood smear, and the immunophenotyping method has been found with R(2) = 0.900, P < 0.001 and R(2) = 0.897, P < 0.001, respectively. The slope of 1.1 and intercept of minus 5 cells/microL of the regression equation between HFL-count and ASC (smear) do indicate an excellent quantification of the HFL-count, as well. CONCLUSION: The fully automated SYSMEX XE-2100 HFL-count identifies and quantifies the ASC cells (activated B-lymphocytes) with high precision and reliability in patients without hematology system diseases, thus providing a potential screening and monitoring tool for any patient with suspected infection. Additional studies are required to comprehend in more detail the full clinical utility of an HFL (ASC) count as a potential diagnostic indicator of inflammation, infection, or sepsis.

[The population census in Nigeria 1991: geographical aspects of a political poker game]. / Die Volkszahlung in Nigeria 1991 -- Geographische Aspekte eines politischen Pokers.

PIP: The population of Nigeria has been estimated at more than 100 million by various sources. The UN in 1987 estimated it at 87 million, the World Bank at 106.2 million, and the Nigerian National Population Commission at 112.3 million. However, the 1991 census, which was carefully conducted, came up with only 87.5 million, whereas according to the World Bank the number should have exceeded 120 million. The discrepancy of 30 million provoked strong reaction among politicians in the country. 5-year average growth rates between 1970 and 1990 indicated an increase from 26.6% to 37.9%; therefore, the population during the 28-year period from 1963 and 1991 must have approximated 100 million. The figure of 112.3 million would require a growth rate of 34.9%, which was plausible from the early 1970s. The results of the 1991 census have pointed to an enigmatic curiosity: was it an accident that the North has registered the highest annual growth rates dating back to 1963, or even 1952? The political infighting and series of coups d'etat by generals may also be correlated to this numerical distortion, since all these generals were Northerners. An accurate analysis was not possible because of the paucity of data. The census of 1991 has not been fully disclosed until the present time [August 1994], strengthening the case of the skeptics, although the full publication of the figures has to do with the political situation in Nigeria. The democratization process was halted after June 1992, especially after the invalidation of the results of the presidential election and the seizing of power by General Abacha. In the event that a democratic government arises, perhaps the figures of the 1991 census will be published, which could also explain the lower growth rate of the economic centers in the Southwest and the Southeast. Nigeria sorely needs more reliable census data for planning because of a one-sided export structure (95% of foreign currency is earned from oil), neglected agriculture, and migration to the cities.^ieng

[The population census of Nigeria, 1991--geographic aspects of a political poker game]. / Die Volkszahlung in Nigeria 1991--geographische Aspekte eines politischen Pokers.

PIP: This article focuses on the discrepancy between population estimates for Nigeria and the results of the 1991 census. They note that the census figure of 88.5 million inhabitants was 30 million less than expected. Geographic aspects of the discrepancy and possibilities for evaluating the census are discussed.^ieng