Effect of iron on serum 25-hydroxyvitamin D and 24,25-dihydroxyvitamin D concentrations.

In 13 of 17 infants (aged 10.5 +/- 4.3; mean +/- SD mo) with iron-deficiency anemia, the serum 24,25-dihydroxyvitamin D concentration was below the normal range and in 9 of these 13 the serum 25-hydroxyvitamin D concentration was below the normal range despite the fact that these infants received 10 micrograms vitamin D/d from the age of 1 mo. The infants were treated with intramuscular iron dextran (Imferon). The iron-dextran treatment increased the hemoglobin and serum iron concentrations as well as 25-hydroxyvitamin D and 24,25-dihydroxyvitamin D concentrations. It is known that iron deficiency impairs fat and vitamin A intestinal absorption. Therefore, it is suggested that absorption of vitamin D may also be impaired. This may contribute to the development of vitamin D deficiency. Iron supplementation may have improved the absorption of vitamin D in the small intestine and hence increased the vitamin D concentration in the plasma.     

Evaluation of anaerobic performance capacity by the isokinetic Ariel computerized exercise system-reliability and validity.

The present study examines the reproducibility and validity of computerized muscle strength and endurance evaluation protocols using the Ariel Computerized Exercise System (ACE). Since the ACE has only recently become commercially available, there are no published normative data for various exercises, nor are the measurements' accuracy and validity for the various exercise protocols documented. Twenty males (17 to 30 years old) performed a set of isokinetic maximal leg and arm exercises on the ACE Multi Function Unit twice on 2 separate days. Test-retest correlation coefficient ranged from 0.44 (bench press) to 0.91 (bench pull and leg extension flexion). Thirty additional male subjects (16 to 31 years old) performed, on 2 separate days, the Wingate Anaerobic Test (WAnT) (leg), and various force and endurance leg exercises (squat) on the ACE. Correlation coefficients of the various performance indices between the 2 test systems ranged from -0.02 to 0.23. The results obtained on the ACE indicate moderate to high reproducibility and low concurrent validity with WAnT.     

Crisis-related observations in competition: a case study in basketball

This study presents a unique observational approach to basketball, based on the theory of psychological performance crisis in competition. The approach used takes into account the responses of a player's actions to significant social factors such as team-mates, spectators, the coach and the referees. The contribution of this approach beyond traditional observational techniques is discussed. In our investigation, a single case design was used, in which a professional basketball player was observed during 10 home and 3 away games of the regular season. The relations between the observations and the crisis concept are discussed in detail. In addition, some relevant methodological and applied aspects are presented.     

Amoxicillin and clavulanic acid concentrations in gingival crevicular fluid

Abstract The β-lactams are bactericidal antibiotics, but some of them may be inactivated by bacterial β-lactamases which destroy the β-lactam ring. The inactivation of amoxicilhn by β-Iactamases of gram negative anaerobic bacteria can be circumvented by the addition of clavulanic acid, a β-lactamases inhibitor. Thus, most of these bacteria are susceptible to this combination. The aim of this study was to investigate the concentrations of amoxicillin and clavulanic acid in gingival crevicular fluid (GCF). These concentrations were measured in 20 patients with rapidly progressive periodontitis 1 h after a dose of 500 mg (1 tablet Augmentin®) on day 0 and 1 h after the 10th intake on day 3. For the sampling of GCF, Periopapers® were introduced in 16 gingival sites per subject and time. The GCF volumes collected were estimated using the Periotron 6000®. A high performance liquid chromatography method has been developed for the determination of amoxicillin and clavulanic acid in microsamples (1 to 10 μl) of GCF. The concentrations of amoxicillin and clavulanic acid were respectively, 14.05 μg ml^-1 and 0.40 μg ml^-1 at day 0.13.93 μg ml^-1 and 0.37 μg ml^-1 at day 3. Effective levels of amoxicillin and clavulanic acid, well above the minimal inhibitory concentrations of some susceptible periodontal anaerobes (P. intermedia) involved in destructive periodontal diseases, are achieved following the multiple administration of amoxicillin combined with clavulanic acid.     

Tests for the determination of the effect of antimitotic products on immune reactions

The differences reported by various authors in regard to the inhibitory effect of the same antimitotic product on the production of antibodies, may be attributable in particular to the antigen used and to the technique of administration of the product. These differences have made it necessary to work out a test that is not subject to criticism in these respects.

After an investigation of the cytological reactions provoked in the mouse by various antigens, the authors have singled out three of these antigens: human albumin, the poliomyelitis virus and an allogeneic skin graft. The hyperbasophilic cells which are predominantly present in the lymphoid centres are, respectively, lymphocytes for the first, plasmocytes for the second and histiocytes for the third of these antigens.

In view of the different mechanisms of action that are possible with the different antimitotic products the authors used three methods of administration: entirely `before' the antigenic stimulus; total dose administered entirely `after' the antigenic stimulus; total dose administered partially `before' and partially `after' the antigenic stimulus.

     

Gender paradox in cardiac calcium deposits in middle-aged and elderly patients: mitral annular and coronary calcifications interrelationship

OBJECTIVES: mitral annular calcification (MAC) occurs mainly in middle-aged and elderly patients and can lead to serious clinical consequences. Male predominance in the prevalence of coronary disease is well-established. Paradoxically, the prevalence of MAC, which is theoretically based on the same etiological mechanisms as coronary atherosclerosis, seems to be predominant in postmenopausal women. The goal of this work was to investigate gender influences on interrelationship between MAC and coronary calcifications (CC) in the same population of middle-aged and elderly patients with increased cardiovascular risk. METHODS: the study comprised 522 patients (284 men and 238 postmenopausal women, aged 52-80 years, mean 65+/-6), who were recruited to the International Nifedipine GITS Study of Intervention as a Goal in Hypertension Treatment (INSIGHT) study in our region. They underwent both fast spiral computed tomography of the heart and echo-Doppler. MAC was defined as advanced when its thickness was > or =5mm; otherwise it was defined as trivial. RESULTS: there were 37 (16%) women and 25 (9%) men with advanced MAC (AMAC), 97 (41%) women and 118 (42%) men with trivial MAC and 104 (44%) women and 141 (50%) men without MAC. The prevalence of any type of CC was significantly higher among men (P=0. 001). In sharp contrast to the distinct male predominance in coronary disease, AMAC was more prevalent among women. In patients without CC prevalence was 9 and 4%, increasing to 16 and 8% in those with nonsevere CC and to 38 and 14% in patients with severe CC, respectively (P=0.001). Multivariate analysis showed that AMAC can predict the presence of severe CC in women and men, with OR of 4.1 and 2.6 (CI 1.2-14.8 and 1.0-10.6) and coronary disease with OR of 2. 5 and 2.5 (CI 0.6-10.6 and 1.0-6.4), respectively. CONCLUSIONS: AMAC signifies a high probability of coronary atherosclerosis in patients of both genders. The inverted gender predominance in the prevalence of annular calcification and CC could be explained by additional etiological (likely osteoporotic) mechanisms of MAC development among postmenopausal women.     

Effect of prolonged moderate and severe energy restriction and refeeding on plasma leptin concentrations in obese women.

BACKGROUND: Plasma leptin in humans is subject to both long- and short-term regulation; it correlates with indexes of body fat that can only change slowly. However, short-term fasting causes large and rapid decreases. OBJECTIVE: We tested the interactions between energy intake and fat loss on plasma leptin during prolonged moderate and severe energy restriction, with a view to understanding mechanisms of control. DESIGN: Postabsorptive leptin was measured with an enzyme-linked immunosorbent assay specific for the human peptide in 21 obese women aged 41 +/- 3 y (weight: 102 +/- 4 kg; 48 +/- 1% body fat) after 1 wk of a weight-maintaining diet and then weekly for 4 wk during a total fast (group 1); a 1.9-MJ/d all-protein, very-low-energy diet (VLED) (group 2); or a low-energy, balanced-deficit diet (BDD) providing 50% of maintenance energy (group 3). In groups 1 and 2, leptin was also measured after 1 wk of refeeding with a diet equivalent to the BDD. RESULTS: Mean leptin decreased markedly by up to 66% (P < 0.001) at week 1 of energy restriction and then gradually thereafter. The change in leptin per kilogram fat mass correlated with that in glucose concentrations [r = 0.538 (P = 0.012) at week 1 and r = 0.447 (P = 0.042) at week 4] but not with that in fat mass. During refeeding postfasting, leptin increased (P = 0.008), despite an ongoing loss of fat mass and correlated positively with changes in resting energy expenditure. At times with comparable cumulative energy restriction and fat loss between diets, the percentage change in leptin paralleled that in glucose. CONCLUSIONS: In obesity, changes in energy intake over days to weeks are a primary modulator of plasma leptin concentrations that are related to the change in glycemia and are able to override the regulatory influence of fat mass.     

Effect of peritoneal fluid from patients with mild and severe endometriosis on endometrial stromal cell proliferation

The aim of this study was to evaluate and compare the mitogenic effect of peritoneal fluid (PF) from women with mild and severe endometriosis on the endometrial stromal cell proliferation. Increasing concentrations of PF from women with and without mild or severe endometriosis were added to primary endometrial stromal cell cultures and³H-thymidine incorporation was used to assess DNA synthesis in these cultures. PF from women with mild endometriosis induced a statistically significant dose-dependent increase in stromal cell thymidine uptake ranged from 5.8 to 14.5 fold, whereas PF from women with severe endometriosis produced an average 51% inhibition of stromal cell proliferation of compared with cells exposed to non-endometriosis PF or exposed to nutrient medium supplemented with 2.5% calf serum alone. PF samples from patients with stage I endometriosis induced a statistically dose-dependent increase in stromal cell proliferation, whereas PF from patients with stage IV endometriosis caused a significant inhibition.