Ultrastructural changes in otoconia of osteoporotic rats

The etiology of benign paroxysmal positional vertigo (BPPV) remains obscure in many cases and women are affected more often than men. A recent prospective study, performed in women >50 years of age suffering from recurrent BPPV, showed associated osteopenia or osteoporosis in a large percentage of these patients. These results suggested the possible relationship between recurrent BPPV and a decreased fixation of calcium in bone in women >50 years. To test this hypothesis, an experimental study was performed in adult female rats. Utricular otoconia of female rats in which osteopenia/osteoporosis was induced by bilateral ovariectomy (OVX) were compared to those of sham-operated adult females rats (SHAM), as control group. FIRST STUDY: The morphology of theutricles of OVX and SHAM rats was analyzed with scanning electron microscopy. In osteopenic/osteoporotic rats, the density of otoconia (i.e. the number of otoconia per unit area) was decreased (p = 0.036)and their size was increased (p = 0.036) compared to the control group. SECOND STUDY: To test the role of calcium turnover in such morphological changes, utricular otoconia of 2 other groups of OVX and SHAM rats, previously injected with calcein subcutaneously, were examined by conventional and epifluorescence microscopy. In epifluorescence microscopy, labeling with calcein showed no significant fluorescence in either group. This finding was interpreted as a lack of external calcium turnover into otoconia of adult female rats. The ultrastructural modifications of otoconia in osteopenic/osteoporotic female adult rats as well as the role of estrogenic receptors in the inner ear are discussed. The possible pathophysiological mechanisms which support the relationship between recurrent BPPV in women and the disturbance of the calcium metabolism of osteopenia/osteoporosis are debated.

Growth curves for cardio-metabolic risk factors in children and adolescents

OBJECTIVE: This study developed percentile curves for anthropometric (waist circumference) and cardiovascular (lipid profile) risk factors for US children and adolescents. STUDY DESIGN: A representative sample of US children and adolescents from the National Health and Nutrition Examination Survey from 1988 to 1994 (NHANES III) and the current national series (NHANES 1999-2006) were combined. Percentile curves were constructed, nationally weighted, and smoothed using the Lambda, Mu, and Sigma method. The percentile curves included age- and sex-specific percentile values that correspond with and transition into the adult abnormal cut-off values for each of these anthropometric and cardiovascular components. To increase the sample size, a second series of percentile curves was also created from the combination of the 2 NHANES databases, along with cross-sectional data from the Bogalusa Heart Study, the Muscatine Study, the Fels Longitudinal Study and the Princeton Lipid Research Clinics Study. RESULTS: These analyses resulted in a series of growth curves for waist circumference, total cholesterol, LDL cholesterol, triglycerides, and HDL cholesterol from a combination of pediatric data sets. The cut-off for abnormal waist circumference in adult males (102 cm) was equivalent to the 94(th) percentile line in 18-year-olds, and the cut-off in adult females (88 cm) was equivalent to the 84(th) percentile line in 18-year-olds. Triglycerides were found to have a bimodal pattern among females, with an initial peak at age 11 and a second at age 20; the curve for males increased steadily with age. The HDL curve for females was relatively flat, but the male curve declined starting at age 9 years. Similar curves for total and LDL cholesterol were constructed for both males and females. When data from the additional child studies were added to the national data, there was little difference in their patterns or rates of change from year to year. CONCLUSIONS: These curves represent waist and lipid percentiles for US children and adolescents, with identification of values that transition to adult abnormalities. They could be used conditionally for both epidemiological and possibly clinical applications, although they need to be validated against longitudinal data.

A Differential Role of Volatiles from Conspecific and Heterospecific Competitors in the Selection of Oviposition Sites by the Aphidophagous Hoverfly Sphaerophoria rueppellii

The selection of oviposition sites by syrphids and other aphidophagous insects is influenced by the presence of con- and heterospecific competitors. Chemical cues play a role in this selection process, some of them being volatile semiochemicals. Yet, little is known about the identity and specificity of chemical signals that are involved in the searching behavior of these predators. In this study, we used olfactometer bioassays to explore the olfactory responses of gravid females and larvae of the syrphid Sphaerophoria rueppellii, focussing on volatiles from conspecific immature stages, as well as odors from immature stages of the competing coccinellid Adalia bipunctata. In addition, a multiple-choice oviposition experiment was conducted to study if females respond differently when they can also sense their competitors through visual or tactile cues. Results showed that volatiles from plants and aphids did not affect the behavior of second-instars, whereas adult females strongly preferred odors from aphid colonies without competitors. Odors from conspecific immature stages had a repellent effect on S. rueppellii adult females, whereas their choices were not affected by volatiles coming from immature heterospecific A. bipunctata. The results imply that the syrphid uses odors to avoid sites that are already occupied by conspecifics. They did not avoid the odor of the heterospecific competitor, although in close vicinity they were found to avoid laying eggs on leaves that had traces of the coccinellid. Apparently adult syrphids do not rely greatly on volatile semiochemicals to detect the coccinellid, but rather use other stimuli at close range (e. g., visual or non-volatile compounds) to avoid this competitor.

Exercise capacity and biventricular function in adult patients with repaired tetralogy of Fallot

BACKGROUND: Adult patients with repaired tetralogy of Fallot (rTOF) often have diminished exercise capacity. The primary objective of this study was to examine whether abnormalities of biventricular function play a role in exercise limitation in patients with rTOF. METHODS: This was a retrospective review of 99 adult patients with rTOF. Right ventricular (RV) and left ventricular (LV) function were assessed echocardiographically using the myocardial performance index (MPI). Maximal oxygen consumption (VO(2) Max) was measured during a level 1 cardiopulmonary exercise test. RESULTS: The mean age of the cohort was 34 +/- 11 years (50% females). Although most of the patients reported good functional capacity, the peak Vo(2)max was decreased at 22 +/- 6 mL/kg per minute (66% +/- 13% predicted Vo(2)max for age and sex). The mean RV and LV MPI were 0.30 +/- 0.07 and 0.42 +/- 0.09, respectively. In the multivariate model, higher RV MPI (P = .04) and LV MPI (P = .005) values, representing impaired ventricular function, were associated with diminished Vo(2)max. There was a significant correlation between the RV and LV MPI (r = 0.54, P = .001). CONCLUSIONS: Impairment of RV and LV function, as measured by MPI, is associated with diminished exercise capacity in patients with repaired tetralogy of Fallot. Furthermore, there is a linear relationship between the RV and LV function suggesting that ventricular interactions are contributing to the limited exercise capacity in this group of patients. Strategies aimed at preserving biventricular function or improving adverse ventricular interactions could help to improve functional capacity in these patients.

Abnormalities of very low density lipoprotein apolipoprotein B-100 metabolism contribute to the dyslipidaemia of adult growth hormone deficiency

Increased cardiovascular mortality in adult growth hormone deficiency (GHD) may be, in part, explained by the dyslipidaemia associated with this condition. It is possible that abnormalities of very low density lipoprotein apolipoprotein B-100 (VLDL apoB) metabolism contribute to this dyslipidaemia. To test this hypothesis, we measured VLDL apoB kinetics in adult GH deficient patients (4 females, 3 males; age 50.1 +/- 4.7 yr (mean +/- SEM); BMI 28.2 +/- 1.1 kg/m2; total cholesterol (TC) 6.6 +/- 0.3 mmol/l; triglyceride (TG) 2.8 +/- 0.6 mmol/l; HDL cholesterol 1.1 +/- 0.1 mmol/l) and in control subjects (4 females, 3 male; age 47.0 +/- 4.7 yr; BMI 27.0 +/- 2.6 kg/m2; TC 5.0 +/- 0.4 mmol/l; TG 0.9 +/- 0.2 mmol/l; HDL cholesterol 1.4 +/- 0.1 mmol/l). [1-(13)C] leucine was administered by a primed (1 mg/kg), constant intravenous infusion (1 mg/kg/hr) and VLDL apoB enrichment with 13C leucine was determined using gas-chromatography mass-spectrometry. The GHD patients had a significantly higher hepatic secretion rate of VLDL apoB (15.5 +/- 1.8 mg/kg/day vs 9.4 +/- 0.6 mg/kg/day p = 0.007) and reduced catabolism ofVLDL apoB (metabolic clearance rate; 12.3 +/- 1.7 ml/min vs 24.3 +/- 4.8 ml/min p < 0.05) compared with control subjects. These findings suggest that GH is integrally involved in the regulation of VLDL apoB metabolism.

Integration of adult patients with phenylketonuria into professional life: long-term follow-up of 27 patients in a single centre in Switzerland

BACKGROUND Neonatal screening and treatment of phenylketonuria (PKU) prevent the development of neurocognitive impairment. The degree of dysfunction may be related to metabolic control and responsible for a hampered school career. METHODS This was a retrospective study from a single metabolic unit of a Swiss University Hospital. The time point of diagnosis and all Phenylalanin (Phe) concentrations during the follow-up were recorded. The primary outcome was integration into professional life defined as no professional studies versus accomplished apprenticeship versus high school diploma/university. Phe levels were correlated with professional outcome. The control group consisted of the patients' healthy parents and siblings. RESULTS A total of 27 patients (13 females, 14 males) were included in the study. The mean (SD) follow-up period was 25.1 (7.6) years. The control group consisted of 57 subjects. Overall, 23 patients were diagnosed by neonatal screening, and 4 patients were diagnosed later. All 4 were in the non-professional study group. Compared with the controls there were significantly more patients in the non-professional study group (26% vs 9%, p <0.05) and significantly less in the accomplished apprenticeship group (59% vs 82%; p <0.04). After exclusion of the patients with late diagnosis no significant differences were found with regard to the professional integration between patients and controls. Significant differences in Phe-levels between the three groups could be documented between 2-10 years of age with the highest levels in the non-professional study followed by the accomplished apprenticeship and the high school diploma group (p <0.01). CONCLUSION Patients who are diagnosed by neonatal screening and are consequently cared for are able to accomplish an apprenticeship or a high school diploma.

Polydnavirus DNA of the braconid wasp Chelonus inanitus is integrated in the wasp's genome and excised only in later pupal and adult stages of the female

Many endoparasitic wasps inject, along with the egg, polydnavirus into their insect hosts, the virus being a prerequisite for successful parasitoid development. The genome of polydnaviruses consists of multiple circular dsDNA molecules of variable size. We show for a 12 kbp segment of the braconid Chelonus inanitus (CiV12) that it is integrated into the wasp genome. This is the first direct demonstration of integration for a bracovirus. PCR data indicated that the integrated form of CiV12 was present in all male and female stages investigated while the excised circular virus DNA only appeared in females after a specific stage in pupal-adult development. The data also indicated that after excision of virus DNA the genomic DNA was rejoined. This has not yet been reported for any polydnavirus. Sequence analyses in the junction regions revealed the presence of an imperfect consensus sequence of 15 nucleotides in CiV12, in each terminus of the integrated virus DNA and in the rejoined genomic DNA. Within these repeats two sequence types (ATA, TAC) were observed in the various virus clones and in the clones encompassing the rejoined genomic DNA; they corresponded to the sequence type in the right and left junction, respectively. To explain this, we propose a model of virus DNA replication in which the genomic DNA is folded to juxtapose the direct repeat of the left with that of the right junction; recombination at specific sites would then yield the two types of virus and rejoined genomic DNA.