Free leptin index and thyroid function in male highly trained athletes

OBJECTIVE

Exercise training may cause changes in thyroid function. This thyroid response may be due to exercise-induced modulation of energy metabolism but also of the adipocytes endocrine function. In particular, the role of leptin and of circulating soluble leptin receptor (sOB-R) was unexplored. The aim of this study was to assess the relationships between thyroid function, whole body energy metabolism, and adipokines--mainly leptin and its receptor, sOB-R.

METHODS

We measured serum TSH, free tri-iodothyronine (FT(3)), free thyroxine, leptin, and sOB-R and assessed energy homeostasis by means of indirect calorimetry, in 27 highly trained athletes and 27 sedentary, healthy men.

RESULTS

TSH-FT(3) ratio was lower in athletes (P<0.03), either in sustained power or anaerobic power-sprint athletes (n=13) or marathon runners (n=14). Whole body respiratory quotient was lower in athletes. Fasting serum sOB-R was higher and leptin lower in athletes than controls. Also serum adiponectin, resistin, and retinol binding protein-4 concentrations were different in athletes than in controls. The ratio between leptin and sOB-R, the free leptin index (FLI), was lower in athletes than in controls (0.025+/-0.014 vs 0.085+/-0.049; P<0.001). In multivariate analysis, FLI retained independent association with TSH-FT(3) ratio.

CONCLUSION

Male, elite athletes had lower TSH-FT(3) ratio and FLI than controls while FLI was independently associated with TSH-FT(3) ratio supporting the hypothesis that the level of biologically active leptin is involved in the adaptive response of thyroid function in professional athletes.

Risk prediction models for the development of diabetes in Mauritian Indians

AIMS

To develop risk prediction models of future diabetes in Mauritian Indians.

METHODS

Three thousand and ninety-four Mauritian Indians (1141 men, aged 20-65 years) without diabetes in 1987 or 1992 were followed up to 1992 or 1998. Subjects underwent repeated oral glucose tolerance tests and diabetes was diagnosed according to 2006 World Health Organization/International Diabetes Federation criteria. Cox regression models for interval censored data were performed using data from 1544 randomly selected participants. Predicted probabilities for diabetes were calculated and validated in the remaining 1550 subjects.

RESULTS

Over 11 years of follow-up, there were 511 cases of diabetes. Among variables tested, family history of diabetes, obesity (body mass index, waist circumference) and glucose were significant predictors of diabetes. Predicted probabilities derived from a simple model fitted with sex, family history of diabetes and obesity ranged from 0.05 to 0.64 in men and 0.03 to 0.49 in women. To predict the onset of diabetes, area under the receiver operating characteristic (ROC) curve (AROC) of predicted probabilities was 0.62 (95% confidence interval, 0.56-0.68) in men and 0.64 (0.59-0.69) in women. At a cut-off point of 0.12, the sensitivity and specificity were 0.72 (0.71-0.74) and 0.47 (0.45-0.49) in men and 0.77 (0.75-0.78) and 0.50 (0.48-0.52) in women, respectively. Addition of fasting plasma glucose (FPG) to the model improved the prediction slightly [AROC curve 0.70 (0.65-0.76) in men, 0.71 (0.67-0.76) in women].

CONCLUSIONS

A diabetes prediction model based on obesity and family history yielded moderate discrimination in Mauritian Indians, which was slightly inferior to the model with the FPG but may be useful in low-income countries to promote identification of people at high risk of diabetes.

On the ultrastructure and functional morphology of the male chelicerae (gonopods) in Parasitina and Dermanyssina mites (Acari: Gamasida)

Males of Parasitina and Dermanyssina (Gamasida=Mesostigmata) have chelicerae modified to function as gonopods. The slit-like spermatotreme in the movable digit of the chela in males of Parasitina was studied in three species: in Pergamasus quisquiliarum and Holoparasitus sp. a rather simple slit is indeed present, whereas in Vulgarogamasus kraepelini the structure is represented by a fine duct traversing the movable digit. The spermatodactyl studied in two phytoseioid species (Phytoseiulus persimilis, Blattisocius dentriticus) of Dermanyssina is a slender process arising from the movable digit and containing a fine duct which is formed by cuticular folds. The spermatodactyl of these species thus differs remarkably from that described in Veigaia sp. The diversity of these structures seen in the few taxa studied up to now is discussed under functional and systematic aspects.

Left ventricular function and energy metabolism in middle-aged men undergoing long-lasting sustained aerobic oxidative training

OBJECTIVE

Ageing of the human heart is characterised by morphological, functional and metabolic changes. Short-term interventions and cross-sectional studies in older individuals questioned the possibility that physical exercise may reverse these alterations. In this study we aimed to assess whether in middle-aged men involved in regular and long lasting physical activity these alterations were attenuated.

DESIGN

Left ventricular (LV) magnetic resonance imaging (MRI) and three-dimensional image selected in-vivo spectroscopy (3D-ISIS) (31)P magnetic resonance spectroscopy (MRS) were performed using a 1.5T scanner in 20 healthy, young and 25 healthy middle-aged non-obese men with a sedentary lifestyle (11 young and 14 middle-aged) or undergoing regular aerobic oxidative training (9 young and 11 middle-aged). Insulin sensitivity was estimated by the homeostatic model assessment 2 (HOMA-2) model.

RESULTS

Sedentary young and middle-aged men were not different with respect to LV morphological parameters and systolic function. The phosphocreatine/ATP (PCr/ATP) ratio (marker of high energy phosphates metabolism) and the LV E-peak filling rate/A-peak filling rate ratio (E/A ratio) were lower in sedentary middle-aged than physically active subjects. Parameters of LV systolic function and the PCr/ATP ratio were not different in the middle-aged compared with the young trained men; the E/A peak flow ratio was higher in the middle-aged trained men than in the middle-aged sedentary men. Within the entire population, the PCr/ATP ratio and the E/A peak flow ratio were associated with insulin sensitivity.

CONCLUSIONS

Trained middle-aged subjects showed a better pattern of LV energy metabolism and of diastolic function than their sedentary counterparts. At this age the exercise-related cardiac benefits were detectable when physical exercise was performed regularly and for a long period of time.

The pedipalp of Pseudocellus pearsei (Ricinulei, Arachnida) - ultrastructure of a multifunctional organ

Ricinulei possess movable, slender pedipalps with small chelae. When ricinuleids walk, they occasionally touch the soil surface with the tips of their pedipalps. This behavior is similar to the exploration movements they perform with their elongated second legs. We studied the distal areas of the pedipalps of the cavernicolous Mexican species Pseudocellus pearsei with scanning and transmission electron microscopy. Five different surface structures are characteristic for the pedipalps: (1) slender sigmoidal setae with smooth shafts resembling gustatory terminal pore single-walled (tp-sw) sensilla; (2) conspicuous long, mechanoreceptive slit sensilla; (3) a single, short, clubbed seta inside a deep pit representing a no pore single walled (np-sw) sensillum; (4) a single pore organ containing one olfactory wall pore single-walled (wp-sw) sensillum; and (5) gustatory terminal pore sensilla in the fingers of the pedipalp chela. Additionally, the pedipalps bear sensilla which also occur on the other appendages. With this sensory equipment, the pedipalps are highly effective multimodal short range sensory organs which complement the long range sensory function of the second legs. In order to present the complete sensory equipment of all appendages of the investigated Pseudocellus a comparative overview is provided.

The anatomy and ultrastructure of the suctorial organ of Solifugae (Arachnida)

Solifugae possess an evertable, adhesive pedipalpal organ (suctorial organ) at the tip of the distal tarsus of each pedipalp that is unique among arachnids. When inverted inside the pedipalp, the suctorial organ is covered with two cuticular lips, a dorsal upper lip and a ventral lower lip, but it can be protruded rapidly in order to facilitate grasping prey or climbing on bushes or even climbing on smooth surfaces due to its remarkable adhesive properties. In this study, the suctorial organs of different species from old world families Galeodidae and Karschiidae and new world families Ammotrechidae and Eremobatidae were investigated by means of light microscopy, scanning and transmission electron microscopy. In all representatives, the suctorial organ is formed by an evertable, cuticular pad with a complex internal stabilizing structure. The procuticle of this pad consists of a lattice-like basal plate and numerous stalked structures connected to this basal plate. The shafts of the stalked structures are regularly organized and ramify apically. The surface of the suctorial organ is constituted of a very thin epicuticle overlaying the ramifying apices forming ridges and furrows on the ventral side of the suctorial organ.

Effect of the sporting discipline on the right and left ventricular morphology and function of elite male track runners: a magnetic resonance imaging and phosphorus 31 spectroscopy study

BACKGROUND

Professional, long-term physical training is often associated with morphological and metabolic changes in the heart. This study was undertaken to assess the left ventricular (LV) and right ventricular (RV) morphology and function and the LV high-energy phosphates of athletes trained to a sustained power or aerobic exercise.

METHODS

Magnetic resonance imaging (MRI) of the LV and RV and phosphorous 31 magnetic resonance spectroscopy of the LV were performed by means of a 1.5-T clinical scanner in 23 elite track sprinters (sustained power or anaerobic power sprint training, 100-400 m) or marathon runners (sustained aerobic endurance training) and in 10 sedentary, young, lean men.

RESULTS

Athletes had LV hypertrophy and unaffected chamber size, systolic and diastolic functions, and high-energy phosphates metabolism. Also, the RV of the athletes was hypertrophied in comparison with that of the nonathletic controls, and the systolic and diastolic functions were unaffected; the chamber volume was higher in the sprinters (end-diastolic volume 190 +/- 15 mL) in comparison with that of the marathon runners (174 +/- 19 mL, P < .05) and controls (168 +/- 19 mL, P < .01) even if this difference, when adjusted for body surface area, was maintained only when compared with that of controls (P < .02).

CONCLUSIONS

Left ventricular and RV hypertrophy in athletes is associated with normal systolic and diastolic functions and resting cardiac energy metabolism, supporting its benign nature. A more pronounced RV dilatation was found in the anaerobic power athletes and further investigation is warranted to establish the clinical significance of this training effect.

Fine structure of spermiogenesis, spermatozoa and spermatophore of Saxidromus delamarei (Saxidromidae, Actinotrichida, Acari)

Ultrastructural details of spermiogenesis, spermatozoa and the spermatophore of the early derived actinedid mite Saxidromus delamarei are described. Spermatids and mature sperm cells are provided with up to four acrosomal complexes and nuclei derivatives (chromatin bodies). Due to this reason, the sperm cells may be classified as synspermia, a sperm type found only in some spiders until now. The acrosomal complex is composed of a remarkably complicated vacuole and filament. Other peculiarities of sperm structure correspond to those found in prostigmatic mites, i.e. penetration of the chromatin body by the acrosomal filament and the presence of peripheral invaginations of the plasmalemma. The sperm cells are covered by a thin secretion layer of probably proteinaceous material. Stalked spermatophores are rather large, but simply structured and contain relatively few sperm cells. The results are discussed taking systematical and behavioural aspects into account. In particular, it is suggested that the peculiar mating behaviour of these mites secures both sperm transfer and first male's sperm priority and that this allowed reduction of sperm numbers.

Valence photoionization dynamics in circular dichroism of chiral free molecules: the methyl-oxirane

The dynamical behavior of circular dichroism for valence photoionization processes in pure enantiomers of randomly oriented methyl-oxirane molecules has been studied by circularly polarized synchrotron radiation. Experimental results of the dichroism coefficient obtained for valence photoionization processes as a function of photon energy have been compared with theoretical values predicted by state-of-the-art ab initio density-functional theory. The circular dichroism measured at low electron kinetic energies was as large as 11%. Trends in the experimental dynamical behavior of the dichroism coefficients D(i)(omega) have been observed. Agreement between experimental and theoretical results permits unambiguous identification of the enantiomer and of the individual orbitals.

Increased serum resistin in elite endurance athletes with high insulin sensitivity

AIMS/HYPOTHESIS

Resistin is an adipokine associated with obesity and type 2 diabetes in animal models, but in humans its role remains uncertain. This study was undertaken to test whether serum resistin is related to insulin resistance and markers of low-grade inflammation in elite athletes taken as a model of extreme insulin sensitivity. SUBJECTS MATERIALS AND METHODS: In 23 elite athletes (sprinters, middle-distance and marathon runners) and in 72 sedentary men including lean and obese individuals with NGT, and obese individuals with IGT or new-onset type 2 diabetes, we assessed insulin sensitivity using a whole-body insulin-sensitivity index (WBISI) derived from a 3-h OGTT; energy homeostasis was also assessed by means of indirect calorimetry, along with circulating adipokines and low-grade pro-inflammatory cyto-chemokines.

RESULTS

Professional athletes had increased WBISIs (p<0.001) and lipid oxidation (p<0.03); they also showed higher serum resistin concentrations (p<0.001), although the pro-inflammatory chemokines were not increased in comparison with the other study groups. Resistin was independently associated only with fasting plasma NEFA. Increased resistin was detected in the middle-distance and marathon runners, but not in the sprinters when compared with the lean, young, sedentary individuals.

CONCLUSIONS/INTERPRETATION

Serum resistin concentration is increased in elite athletes, providing evidence against the notion that resistin levels reflect insulin resistance in humans, as seen in animal studies. Increased resistin was observed in aerobic-endurance, but not sustained-power athletes and this feature appeared to be independently associated with parameters of fatty acid metabolism.

Potentiometric sensor for atrazine based on a molecular imprinted membrane

A molecular imprinted polymer (MIP) membrane for atrazine, not containing macropores, was synthesized and implemented in a potentiometric sensor. It is expected to work like a solid ISE (where the specific carrier are the imprinted sites) the specific carrier being the imprinted site. The active ion is the protonated atrazine, positively charged. To form this species the determination is carried out in acidic solution at pH lower than 1.8, in which atrazine is prevalently monoprotonated. At these conditions the membrane potential increases with atrazine concentration over a wide concentration range (3 x 10(-5) to 1 x 10(-3)M). The slope of the function E versus logc is about 25 mV/decade, showing that the atrazine form sorbed on MIP is the biprotonated one. The detection limit is determined by the relatively high concentration of atrazine released by the membrane in the sample solution at the considered conditions. It seems to be independent of the atrazine concentration in the internal solution of the sensor, but it depends on the acidity of the solution. The response time is less than 10s and the sensor can be used for more than 2 months without any divergence.

Eruption of supernumerary permanent teeth in a sample of urban primary school population in Genoa, Italy

AIM

The aim of this epidemiological study was to describe the incidence and distribution of hyperdontia in the primary school population in Genoa (Italy) and to check its influence on the development of orthodontic problems in children. The collected data should also help to find out what is the best age range among children to direct a program for early diagnosis and prevention of malocclusion and oral diseases related to hyperdontia.

METHODS

The participating children (total number 1577, 814 males and 763 females, between 6 and 10 years of age) chosen in 19 public primary schools in Genoa have been examined by the same specialist through year 2004. Erupted permanent teeth, presence, position and form of supernumerary teeth, malocclusion presence and class, presence of orthodontic devices, age and sex have been noted down for each child.

RESULTS

The global percentage of hyperdontia was 0.38%, more frequent in males (0.49%) than in females (0.26%). The most common kind of supernumerary tooth was mesiodens (83%). A significant increase of hyperdontia prevalence (from 0.64% to 1.06%) was noticed in children 9 years old. The incidence of malocclusion among children presenting hyperdontia was 83.3%, while the global incidence of malocclusion was 40%. An orthodontic treatment had been planned and started for 20% of children presenting malocclusion.

CONCLUSION

The study has revealed an incidence of hyperdontia much more frequent in males than in females (2:1). The most common site of eruption of supernumerary teeth is maxillary anterior region. Hyperdontia is strictly related with dental malocclusion. The best age range to direct a program of early diagnosis and prevention of malocclusion and hyperdontia is 9 years old children.

Spermatozoa and spermiogenesis of Holocnemus pluchei (Scopoli, 1763) (Pholcidae, Araneae)

Until now, the knowledge on pholcid spermatozoa is based on two species, Pholcus phalangioides and, incompletely, Holocnemus pluchei. To complete this knowledge and to reveal more potential phylogenetic characters, we have investigated sperm ultrastructure and spermiogenesis of H. pluchei. We found that the sperm cells of this species are clearly different from those of P. phalangioides with respect to: (1) the lack of specialization in the cylindrical acrosomal vacuole; (2) a nuclear canal which is located in the periphery and not in the center of the nucleus; (3) a more prominent postcentriolar elongation of the nucleus; (4) the presence of "inner microtubules" in the implantation fossa in early and mid-spermatids; (5) the absence of a helical band of nuclear material; (6) the proximal centriole which is not prolonged; (7) the types of secretion in the seminal fluid (only two types in H. pluchei). Similarities in the spermatozoa of both species concern: (1) a large implantation fossa which contains large amounts of glycogen in mature spermatozoa; (2) absence of a centriolar adjunct; (3) an axonemal basis located in the posterior part of the implantation fossa; (4) the formation of the so-called cleistospermia in the vas deferens. Our results strongly support systematic relationships within Pholcidae placing these two species in different subgroups.

Cardiovascular responses to aerobic step dance sessions with and without appendicular overload

AIM

Several studies showed that exercise intensity during aerobic step dance can be modified varying stepping rate, bench height and manipulating body mass using hand held or adding loads to the torso. The aim of this study was to determine the cardiovascular responses during aerobic step dance using an overload strategy not yet investigated: appendicular overload.

METHODS

Ten healthy and moderately trained women (mean+/-SD: age 27+/-3.4 years, height 167.8+/-4.6 cm, body mass 55.7+/-4.7 kg, body mass index 19.8+/-1.6, VO2max44.4+/-6.1 mLxkg-1xmin-1) performed an incremental treadmill test to determine VO2peak, the VO2-heart rate (HR) and rating of perceived exertion (RPE)-HR relationships. Within 1 week from the laboratory test, the subjects performed two identical aerobic step dance routines: one using a track suit with loads placed in pockets close to the legs and arms and another without overload.

RESULTS

The appendicular overload (10% of body mass) significantly increased the exercise intensity from 84.5% to 89.8% of HRmax corresponding to 68.9% and 78.3% of VO2peak, respectively (P<0.01). Similarly, RPE increased from 12.1 to 15.7 (P<0.001). The estimated VO2 and the caloric expenditure rose from 30.3 to 34.7 mLxkg-1xmin-1 and from 251 to 288 kcal, respectively.

CONCLUSION

This study shows that the use of appendicular overload significantly increases the energy cost of aerobic step session similarly to other overload strategies already reported in the literature.

Aluminium speciation in natural water by sorption on a complexing resin

Very stable aluminium complexes may be present in natural waters, which can be detected only using appropriate methods. One of them is the resin titration based on the sorption of aluminium on a strongly sorbing resin, Chelex 100. It was here used to detect strong aluminium complexes, and to characterize them by determining their concentration, and the corresponding stability constant. High and low salinity waters were sampled in different sites in the North of Italy. In all the samples aluminium complexes with high stability constant, up to 10(17.4) M(-1) in the less acidic solution, were detected. The stability constant depends mainly on the solution acidity, increasing with increasing pH up to 7. The concentration of the ligands responsible for the strong complexation is similar to that of aluminium (from 0.5 to 1.5 microM), or somewhat lower in the case of estuarine and sea waters. A small fraction of aluminium (from 0% to 2%) in freshwaters, higher in estuarine and sea waters (14% and 10%, respectively), is present in weakly bound forms which could also be the hydrolysis products. The conditional constants of the strong complexes were determined for the different samples examined. They were found to be slightly lower in the case of the high salinity waters, in which a value of 10(16.1) M(-1) at pH 7.5 was obtained. This is probably due to the higher ionic strength in marine water, which strongly influences the complexation of trivalent metal ions, as seen for example also in the hydrolysis. It could be deduced that similar substances, but at different concentration, would be responsible for the aluminium complexation in the sea and freshwaters here examined. They could be natural organics like fulvic substances, or better some particular complexing sites in this substances with very high affinity for aluminium.