Quantitative ultrasound at the hand phalanges in 2850 females aged 7 to 77 yr: a cross-sectional study

In the study, skeletal status was evaluated in 2850 females aged 7 to 77 yr using quantitative ultrasound (QUS amplitude-dependent speed of sound [Ad-SoS]). Ad-SoS ranged from 1923 +/- 30 to 1876 +/- 81 m/s, and the peak value (2121 m/s) was achieved in 19-yr-old females. Ad-SoS increased significantly between subgroups aged 11 and 12 yr, 12 and 13 yr, 13 and 14 yr, 14 and 15 yr, and 15 and 16 yr. After the age of 19 yr the only significant drop was noted between age groups 47 and 48 yr. Ad-SoS was regressed on age, weight, and height for age ranges 7 to 11 yr.(before an increase in Ad-SoS), 12 to 19 yr (from the onset of the increase to the peak value), and older than 19 yr to menopause. In females after menopause, years since menopause (YSM) were taken into consideration. In the two youngest groups Ad-SoS was affected positively by age, and in the two next groups, age had a negative influence on Ad-SoS, whereas weight had a negative and height a positive influence in all groups. YSM did not influence the Ad-SoS value. It was concluded that QUS measurements at the hand phalanges are a useful tool in assessment of skeletal status in the female population.

[Coexistence of occupational exposure to lead and sleep apnea syndrome as a cause of hypertension and arrhythmias. A case report]

A case of a 54-year-old man occupationally exposed to lead with diagnosed obstructive sleep apnea, hypertension and implanted artificial pacemaker due to atrioventricular dissociation of the third degree and pauses in sinus rhythm is presented.

[Genotoxicity effect of chronic lead exposure assessed using the comet assay]

BACKGROUND

Lead, an important xenobiotic, is globally well distributed. The IARC has classified inorganic lead compounds as possibly carcinogenic to humans. The study was designed to assess genotoxic effects in workers occupationally exposed to Pb.

MATERIALS AND METHODS

The study comprised 62 male workers with chronic exposure to lead and 22 matched non-exposed men. DNA damage was assessed by single cell gel electrophoresis (known as comet assay) using peripheral blood lymphocytes. The level of DNA damage was determined as the percentage of cells with comets.

RESULTS

Mean blood Pb (PbB) concentrations in workers exposed to lead were significantly higher than in controls (422.6 +/- 181.2 microg/l vs. 81.0 +/- 37.84 microg/; p< 0.01). The level and the grade of DNA damage were significantly higher in workers exposed to lead (total--12.55 +/- 7.93%; grade 1--9.05 +/- 5.78%; grade 3--1.05 +/- 1.28%; p < 0.05) than in controls (total--6.63 +/- 3.05%; grade 1--5.68 +/- 2.32%; grade 3--0.35 +/- 1.04%; p < 0.05). The highest level and the degree of DNA damage were observed in workers with PbB over 500 microg/l and the lowest in workers with PbB lower than 200 microg/l.

CONCLUSIONS

Our results suggest that lead, particularly in people with chronic occupational Pb exposure and high PbB may induce DNA damage in peripheral lymphocytes detected by the comet assay, and thus should be regarded as a potential agent harmful to the human chromosome. The comet assay can be used to monitor and evaluate biological toxic effects in humans occupationally exposed to lead.

Effect of simulated intestinal fluid on drug permeability estimation across Caco-2 monolayers

Presently, the Caco-2 cell culture model is widely used during drug discovery and development as a predictive tool for the oral absorption of drug candidates. For transport experiments in the Caco-2 system, HBSS-like buffered salt solutions are commonly used, although different shortcomings have been associated with the use of these buffers. In this paper, we investigated the effect of using fasted state simulated intestinal fluid (FaSSIF) as potential biorelevant medium for the drug permeability estimation across Caco-2 monolayers. The transport characteristics of 19 model compounds were determined in the Caco-2 cell culture model in the presence of FaSSIF as compared to classic transport medium. A sigmoidal relation was obtained when the estimated P(app), s of the apical to basolateral transport were plotted versus the reported values of the fraction absorbed in man. Although no effect of FaSSIF as compared to classic transport medium (TM) was observed on the total predictability of the model, an impact was demonstrated (1) on the bi-directional transport of actively transported drugs (including talinolol, digoxin and doxorubicin), (2) on recovery and (3) on the solubility and permeability estimation of poorly water-soluble drugs. The observed differences may be attributed to a P-gp inhibitory effect of sodium taurocholate (NaTC), micellar encapsulation by the NaTC/lecithin mixed micelles and/or an increase of the solubility of lipophilic drugs. As the experimental conditions should mimic the physiological in vivo conditions, the use of FaSSIF as medium during Caco-2 experiments may improve the biorelevance of the model.

Treatment of cutaneous leishmaniasis among travellers

Leishmaniasis is endemic in 88 countries on five continents. There are 1-1.5 million cases of cutaneous leishmaniasis reported yearly worldwide. There has been a sharp increase in recorded cases over the last 10 years. Based on geographical distribution, cutaneous leishmaniasis is divided into Old World and New World leishmaniasis. In the past, species could be inferred from geographical setting or determined by performing culture and isoenzyme analysis. The recently developed and now widely available PCR technology allows a rapid diagnosis with determination of most species, and thus enables a species-orientated treatment. While the Old World species mostly cause benign and often self-limiting cutaneous disease, the American species cause a broad spectrum of conditions from benign to severe manifestations, including mucosal involvement. The response to treatment varies according to the species. Therefore, a species-specific approach is proposed. Drugs for systemic and topical treatment are presented and discussed with regard to their application, use and adverse effects. Indications for local or systemic treatment are proposed. Drugs under investigation are also mentioned. An overview of published treatment options and a treatment recommendation is given for each of the most important species. The level of evidence of the studies leading to these recommendations is given.

[Individual protection devices--opinion and practice of occupational medicine physician]

Technological developments have led to changes in work conditions and the character of work itself that modify the responsibilities and tasks of occupational medicine physicians. Their major task is to protect workers' health through primary prevention, which means the employment of all available measures to prevent adverse health effects resulting from working conditions unfavorable to human health. Statistical data on the incidence of occupational diseases and accidents at work in Poland show that despite many beneficial changes, better labor organization or new technologies in production and services, social and economic consequences of exposure-related diseases induced by so called hard harmful agents in the work environments are still the major problem, hence the significance of prevention. Activities aimed at preventing hazards at workplace should be carried out by employers, safety and work hygiene services and physicians involved in prophylactics. In addition, the selection and supply of individual protectors as well as their use by workers to protect themselves against dangerous and harmful factors occurring in the work environment play an essential role. The authors discuss the significance of using individual protectors from the viewpoint of occupational medicine physicians, and the tasks of this group of physicians in the light of epidemiology of occupational diseases induced by various agents present in the work environment.

Plasma leptin and hypothalamic neuropeptide Y and galanin levels in Long-Evans rats with marked dietary preferences

Neuropeptides present in the hypothalamus and new messengers in the periphery such as leptin modulate food intake in mammals. Neuropeptide Y (NPY) and galanin in microdissected brain areas and plasma leptin levels were measured by specific radioimmunoassays during the resting period in rats selected for their strong preference either for carbohydrate or fat, but with identical energy intake. NPY concentrations were 23% lower (p <.02) in carbohydrate-preferring (CP) than in fat-preferring (FP) rats in the parvocellular part of the paraventricular nucleus (PVN), which is one of the main areas involved in the regulation of feeding behavior. On the other hand, galanin was significantly (+25%, p = .03) higher in CP rats than in FP rats in the magnocellular part of the PVN. Plasma leptin was more than 50% higher in FP rats than in CP rats (p < .01) and highly correlated with the fat preference (r = 0.57; p = .003) and body weight gain. We conclude that the rats with a spontaneous and marked dietary preference have a characteristic peptidergic profile. Due to their anatomical relationships, neuropeptide Y could act in conjunction with galanin in a peptidergic balance located in the paraventricular nucleus. This model integrates information provided by the energy stores and translated by peripheral messengers such as leptin which could act in a counterregulatory manner in order to limit the overweight induced by the ingestion of unbalanced diets.

Progress in high field MRI at the University of Florida

In this article we report on progress in high magnetic field MRI at the University of Florida in support of our new 750MHz wide bore and 11.7T/40cm MR instruments. The primary emphasis is on the associated rf technology required, particularly high frequency volume and phased array coils. Preliminary imaging results at 750MHz are presented. Our results imply that the pursuit of even higher fields seems warranted.

A novel three-component butenolide synthesis

[reaction: see text]. 5-Acylamino butenolides can be assembled by a multicomponent reaction (MCR) of isocyanides, glyoxals, and acetophosphonic acid diethylesters, followed by a intramolecular Wittig-type reaction. The reaction can be performed either in one pot or with the isolation of the intermediate Passerini product. This versatile reaction offers three independent inputs displayed in the final product. Applications in combinatorial chemistry and natural product synthesis can be envisioned.

Opposite regulation of hypothalamic orexin and neuropeptide Y receptors and peptide expressions in obese Zucker rats

Many hyothalamic neuropeptides are involved in the regulation of food intake and body weight. The orexins (OX) which are synthesized in the lateral hypothalamus are among the most recently characterized whereas neuropeptide Y (NPY) belongs to a group of "older" peptides extensively studied for their effects on feeding behavior. Both stimulate food ingestion in rodents. In this experiment, we measured the expressions of these peptides as well as of their receptors (OX1-R and OX2-R, Y1 and Y5) in the hypothalamus of obese hyperphagic and lean Zucker rats by real-time RT-PCR using the TaqMan apparatus. NPY mRNA expression in the obese rats was significantly increased by a factor of 10 (P < 0.002) whereas expressions of the Y1 and Y5 receptors were decreased by 25% (P < 0.01) and 50% (P < 0.002), respectively. Their prepro-orexin mRNA expression was more than twofold decreased (P < 0.01) and expressions of their OX receptors 1 and 2 mRNA were five- and fourfold increased (P < 0.05), respectively. An inverse phenomenon was therefore noted between the two peptides: for NPY, increased levels and downregulation of receptors; and for OX, diminished levels with upregulation of receptors. The reasons for these changes might be linked to the absence of leptin signaling as similar profiles are found in the ob/ob mice. For orexins at least, other factors such as hyperglycemia might be involved. Based on anatomical considerations, a direct effect of NPY or of other brain peptides such as CRH cannot be excluded. We conclude that the diminution in the OX tone might participate in a counterregulatory system necessary to limit the noxious effects of NPY on food intake and body weight.

Central and peripheral dysregulation of melanin-concentrating hormone in obese Zucker rats

Melanin concentrating hormone (MCH) is a peptide synthesized in the lateral hypothalamus which stimulates food ingestion and leptin secretion in rodents. In this experiment, we measured the expressions of MCH as well as of its receptor (SLC-1) in the hypothalamus of obese hyperphagic and lean Zucker rats by quantitative real time RT-PCR. MCH mRNA expression in the obese rats was significantly increased by a factor of five (P<0.01) whereas expression of SLC-1 was decreased by more than 50% (P<0.05). Circulating levels of leptin and MCH were increased in the plasma of obese Zucker rats when compared to lean rats (38-fold and 1.7-fold, respectively, P<0.001 and P<0.01). However, individual MCH levels were not directly correlated to leptin levels in the lean (functional leptin receptor) or in the obese (non-functional leptin receptor) Zucker rats. These results indicate that the absence of leptin signaling in rats is associated with an increased hypothalamic expression and circulating release of MCH, contributing to their obesity syndrome.

A temperature-dependent quantum mechanical/neural net model for vapor pressure

We present a temperature-dependent model for vapor pressure based on a feed-forward neural net and descriptors calculated using AM1 semiempirical MO-theory. This model is based on a set of 7681 measurements at various temperatures performed on 2349 molecules. We employ a 10-fold cross-validation scheme that allows us to estimate errors for individual predictions. For the training set we find a standard deviation of the error s = 0.322 and a correlation coefficient (R(2)) of 0.976. The corresponding values for the validation set are s = 0.326 and R(2) = 0.976. We thoroughly investigate the temperature-dependence of our predictions to ensure that our model behaves in a physically reasonable manner. As a further test of temperature-dependence, we also examine the accuracy of our vapor pressure model in predicting the related physical properties, the boiling point, and the enthalpy of vaporization.

[Malaria--chemoprophylaxis 2001]

An estimated 20,000 to 30,000 cases of imported malaria are annually diagnosed in industrialised countries. Some 700 of them concern Swiss travellers and foreign guests. Exposure prophylaxis and chemoprophylaxis for high risk destinations lower the risk of malarial disease. The latter is defined as regular intake of antimalarial drugs in subtherapeutic dosage in order to suppress the development of clinical disease. Drugs are usually taken from one week before travel until four weeks after return from an endemic area. Mefloquine, doxycycline, chloroquine plus proguanil, and presumably soon also atovaquone plus proguanil are available in Switzerland for chemoprophylaxis.

Moving from medical student placement to a community-academic partnership with a rural community

This article explains a partnership-based community education model, which uses as an example a partnership between the Center for Healthy Communities in the Department of Family and Community Medicine at the Medical College of Wisconsin (MCW) and the rural Marion area of central Wisconsin. MCW is similar to other medical schools in that it has a strong history and philosophy of placing students in communities for educational purposes. This article describes how the Center for Healthy Communities is moving beyond student placement to true partnership building. The center followed four stages of development as it built a partnership with this rural Wisconsin community: (1) establish and build relationships, (2) develop common goals, (3) develop and implement programs and (4) maintain and expand progress. The center also applied a set of principles in developing the partnership. By following the stages and applying the principles, the center found that two elements were key to building a partnership for medical student education and community health improvement: long-term commitment and ability and willingness to spend time in the community. As a result, a meaningful, ongoing partnership developed that benefits both the community and MCW.

The long-term safety and efficacy of pramipexole in advanced Parkinson's disease

Objective: To assess the long-term safety and efficacy of pramipexole in advanced Parkinson's disease over a four year time period.Methods: This study is an open-label extension trial of pramipexole for Parkinson's disease open to patients completing a double-blind placebo controlled safety and efficacy trial of this drug. Three hundred and six patients entered the trial. These patients had moderate to severe PD (stage II-IV Hoehn and Yahr during off time) and were experiencing motor fluctuations. Patients were titrated over a six week period and then entered a maintenance phase which lasted up to 50 months. Patients were evaluated every 3 months using the Unified Parkinson's Disease Rating Scale (UPDRS II, III and IV) and modified Schwab and England scale (S/E).Results: Sixty-four percent (197) of the 306 patients who entered this study completed it. Patients showed steady improvement over the 6 week ascending dose interval when pramipexole was reintroduced into the trial as the open-label study medication. Over the duration of the trial patients slowly returned to their baseline levels. This was true for all measures evaluated except for the UPDRS part IV. On UPDRS part IV patients remained below their baseline score which indicated an improvement for the duration of the study. Patterns similar to the overall scores were seen when the individual components of the UPDRS scale part II for "on" and "off" periods and part III were evaluated. However tremor during "on" periods showed improvement over baseline for the duration of the trial. The most common adverse events secondary to pramipexole occurring in greater than 10% of patients included dyskinesias, asymptomatic orthostatic hypotension, dizziness, insomnia, and hallucinations.Conclusion: Pramipexole was well tolerated for up to 4 years. Pramipexole treatment appeared to show continued efficacy in the treatment of Parkinson's disease for 3 years in this open-label descriptive study. After 3 years there was a gradual return to baseline motor states perhaps suggesting progression of Parkinson's disease.

A quantum mechanical/neural net model for boiling points with error estimation

We present QSPR models for normal boiling points employing a neural network approach and descriptors calculated using semiempirical MO theory (AM1 and PM3). These models are based on a data set of 6000 compounds with widely varying functionality and should therefore be applicable to a diverse range of systems. We include cross-validation by simultaneously training 10 different networks, each with different training and test sets. The predicted boiling point is given by the mean of the 10 results, and the individual error of each compound is related to the standard deviation of these predictions. For our best model we find that the standard deviation of the training error is 16.5 K for 6000 compounds and the correlation coefficient (R2) between our prediction and experiment is 0.96. We also examine the effect of different conformations and tautomerism on our calculated results. Large deviations between our predictions and experiment can generally be explained by experimental errors or problems with the semiempirical methods.

KO's and organisation of peptidergic feeding behavior mechanisms

Feeding behavior results from complex interactions arising between numerous neuromediators, including classical neurotransmitters and neuropeptides present in hypothalamic networks. One way to unravel these complex mechanisms is to examine animal models with a deletion of genes coding for the different neuropeptides involved in the regulation of feeding. The aim of this review is to focus on feeding and body weight regulation in mice lacking neuropeptide Y (NPY), melanocortins (POMC), corticotropin-releasing hormone, melanin-concentrating hormone, or bombesin-like peptides respectively. The phenotypes, which relate to the deletion of gene coding for the peptides, rarely include changes in body weight and food intake, indicating therefore the existence of redundant mechanisms to compensate for the loss of the peptide. The phenotype is much more marked when the gene deletion is targeted towards the functioning of the peptidergic machinery, e.g. the receptors and especially the POMC and NPY receptors, as well as one subtype of bombesin receptor (BRS-3). These knockout models are also interesting when examining the role of environmental and social factors in the determination of feeding behavior. They have granted us better knowledge of all these integrated and complex mechanisms. Moreover, they are also valuable tools for pharmacological studies when specific antagonists are lacking. From the information obtained by the study of knockouts, it is possible to determine certain targets for selective drugs that could be efficient for the pharmacological treatment of obesity. However, at the present state of our knowledge, it seems necessary to target several peptides in order to get good results with weight loss. It will also be imperative to associate these multitherapies with changes in eating and behavioral habits, in order to obtain complete effectiveness and long-lasting results.

The changes of alpha-amylase activity in serum and different tissues of female rat during sex cycle--isoelectrofocusing studies of alpha-amylase

BACKGROUND

It has been suggested that hormonal changes may influence alpha-amylase activity during sex cycle. The aim of this study was to evaluate these changes in serum and different tissues during sex cycle in female rats.

MATERIAL AND METHODS

The animals were assigned to proestrus, estrus, and diestrus groups depending on vaginal smears. We measured the activities of alpha-amylase in the serum, liver, salivary glands, pancreas and ovary of female rats, serum level of calcium, rat luteinising hormone (rLH) and rat follicle stimulating hormone (rFSH). The serum and tissue amylases were also characterized by wide-range polyacrylamide gel isoelectrofocusing.

RESULTS

Statistically significant changes of alpha-amylase activity were found only in the ovary. The activity of alpha-amylase raised from proestrus (mean 303 +/- 124 IU/g) through estrus (mean 157 +/- 123 IU/g) and declined in diestrus (mean 81.9 +/- 51.6 IU/g). There were no statistically significant changes in the serum, liver, salivary glands and pancreas. We found two isoenzymes of alpha-amylase: one peak of amylase, present in the serum, liver, salivary gland and ovary with the mean isoelectric point of ca 5.34 and another present in ovary and pancreas with mean isoelectric point of ca 8.32. The only tissue found to contain both isoamylases was the ovary. We did not find any correlation between serum calcium level and alpha-amylase activity in the serum and ovary.

CONCLUSION

The pattern of changes of alpha-amylase activity does not depend on the type of isoamylase in the tissue, but probably on the tissue influenced by the sex cycle. The changes of alpha-amylase activity are not mediated by calcium, they seem to result primarily from the profile of sex hormones affecting directly the target tissues.

Dietary composition during fetal and neonatal life affects neuropeptide Y functioning in adult offspring

The aim of this study was to examine the impact of maternal diet during the gestation and lactation periods on the neuropeptide Y (NPY) system in adult offspring. Male Long-Evans rats were obtained from dams fed either on a well-balanced diet (C), a high carbohydrate diet (HC) or a high-fat diet (HF) and fed themselves on the well-balanced diet for their whole life. At 6 months of age, their feeding response to various doses of NPY injected in the lateral brain ventricle was measured in one group and NPY concentrations in microdissected nuclei of the hypothalamic were measured in a second group. The HF rats were lighter than the two other groups (P<0.001). The control rats showed a typical dose-dependent feeding response to NPY. The HC rats showed a continuous increase in the response, starting at the intermediate dose (1.0 microg) only while the HF rats had a maximal response at the lowest dose (0.5 microg). The HF rats ate twice as much as the HC rats at the lowest dose tested 1 h after injection (4.4+/-0.6 vs. 2.7+/-0.4 g; P<0.05), showing therefore the greatest sensitivity to NPY. This change in the sensitivity was not related to hypothalamic NPY concentration as it was not modified in the arcuate and paraventricular nuclei. The diet imposed on the mother could have long-lasting effects on body weight regulation of the offsprings and alter the NPY system likely through modifications at the receptor level.

Neuropeptides and obesity

This review focuses on the expression, content, and release of neuropeptides and on their role in the development of obesity in animal models with single-gene mutations. The balance between neuropeptides that contribute to the control of feeding behavior is profoundly and variously altered in these models, supporting the concept of the existence of several types of obesity. The hypothalamic neuropeptide Y (NPY) and the pro-opiomelanocortin (POMC) systems are the networks most studied in relation to energy intake. Both receive information about the nutritional status and the level of energy storage through insulin and leptin signaling mediated by specific receptors located on POMC and NPY neurons present predominantly in the arcuate nucleus (ARC). When leptin signaling is defective, through a defect in either the receptor (Zucker fa/fa rat, cp/cp rat, and db/db mouse) or in the peptide itself (ob/ob mouse), the NPY system is upregulated as shown by mRNA overexpression and increased peptide release, whereas the content and/or release of some inhibitory peptides (neurotensin, cholecystokinin) are diminished. For the POMC system, there is a complex interaction between the tonic inhibition of food intake exerted by alpha-melanocyte-stimulating hormone (alpha-MSH) and the Agouti-related protein at the level of the type 4 melanocortin receptor. The latter peptide is coexpressed with NPY in the ARC. Corticotropin-releasing factor (CRF) is the link between food intake and environmental factors. It not only inhibits food intake and prevents weight gain, likely through hypothalamic effects, but also activates the hypothalamo-pituitary axis and therefore contributes to energy storage in adipose tissue. The factors that prod the CRF system toward the hypothalamic or hypothalamo-pituitary axis system remain to be more clearly defined (comodulators, connections between limbic system and ARC, cellular location, and type of receptors, etc. ). The pathways used by all of these neuromodulators include numerous brain areas, but some interest has returned to the classic ones such as the ventromedial and lateral hypothalamic areas because of the recent discovery of some peptides (orexins and melanin-concentrating hormone for the lateral hypothalamus) and receptors (CRF type 2 in the ventromedial hypothalamus). All of these pathways are redundant and function in a coordinated manner and sometimes by the novel expression of a peptide in an unusual area. The importance of such a phenomenon in obesity remains to be determined. Even if single-gene mutations are exceptions in human obesity, the study of genetic animal models of obesity has greatly contributed to the understanding of the regulation of feeding behavior and will allow researchers to develop new drug treatments for obesity that have to be associated with drastic changes in lifestyle (feeding, work habits, and physical activity) for a complete efficiency.