The size, shape, density and ring of the dwarf planet Haumea from a stellar occultation

Haumea-one of the four known trans-Neptunian dwarf planets-is a very elongated and rapidly rotating body. In contrast to other dwarf planets, its size, shape, albedo and density are not well constrained. The Centaur Chariklo was the first body other than a giant planet known to have a ring system, and the Centaur Chiron was later found to possess something similar to Chariklo's rings. Here we report observations from multiple Earth-based observatories of Haumea passing in front of a distant star (a multi-chord stellar occultation). Secondary events observed around the main body of Haumea are consistent with the presence of a ring with an opacity of 0.5, width of 70 kilometres and radius of about 2,287 kilometres. The ring is coplanar with both Haumea's equator and the orbit of its satellite Hi'iaka. The radius of the ring places it close to the 3:1 mean-motion resonance with Haumea's spin period-that is, Haumea rotates three times on its axis in the time that a ring particle completes one revolution. The occultation by the main body provides an instantaneous elliptical projected shape with axes of about 1,704 kilometres and 1,138 kilometres. Combined with rotational light curves, the occultation constrains the three-dimensional orientation of Haumea and its triaxial shape, which is inconsistent with a homogeneous body in hydrostatic equilibrium. Haumea's largest axis is at least 2,322 kilometres, larger than previously thought, implying an upper limit for its density of 1,885 kilograms per cubic metre and a geometric albedo of 0.51, both smaller than previous estimates. In addition, this estimate of the density of Haumea is closer to that of Pluto than are previous estimates, in line with expectations. No global nitrogen- or methane-dominated atmosphere was detected.

Aerial pesticide application causes DNA damage in pilots from Sinaloa, Mexico

The use of pesticides in agricultural production originates residues in the environment where they are applied. Pesticide aerial application is a frequent source of exposure to pesticides by persons dedicated to agricultural practices and those living in neighboring communities of sprayed fields. The aim of the study was to assess the genotoxic effects of pesticides in workers occupationally exposed to these chemicals during their aerial application to agricultural fields of Sinaloa, Mexico. The study involved 30 pilots of airplanes used to apply pesticides via aerial application and 30 unexposed controls. Damage was evaluated through the micronucleus assay and by other nuclear abnormalities in epithelial cells of oral mucosa. The highest frequency ratios (FR) equal to 269.5 corresponded to binucleated cells followed by 54.2, corresponding to cells with pyknotic nuclei, 45.2 of cells with chromatin condensation, 3.7 of cells with broken-egg, 3.6 of cells with micronucleus, and 2.0 of karyolytic cells. Age, worked time, smoking, and alcohol consumption did not have significant influence on nuclear abnormalities in the pilots studied. Pesticide exposure was the main factor for nuclear abnormality results and DNA damage. Marked genotoxic damage was developed even in younger pilots with 2 years of short working period, caused by their daily occupational exposure to pesticides.

Organochlorine pesticide level differences among female inhabitants from Veracruz, Puebla and Tabasco, Mexico

Organochlorine pesticides have been used in Mexico in malaria control programs and against ectoparasites. The objective of this study was to compare the levels of organochlorine pesticides: HCB, α-β-γ-HCH, pp'-DDE, op'-DDT and pp'-DDT in adipose tissue of female inhabitants from three Mexican states: Veracruz, Puebla and Tabasco. Data analyses indicated higher β-HCH levels in Puebla inhabitants. When comparing the mean values of the pp'-DDE concentrations among the three states, no statistically significant differences were noted. A trend of increasing concentrations of op'-DDT from Veracruz to Puebla and Tabasco was observed. Significantly higher pp'-DDT concentrations in Veracruz as compared to Puebla and Tabasco were determined. Using factorial analysis of three age categories (>30, 31-50, <51) organochlorine pesticide concentrations increases with age of participants, indicating time of exposure as a principal factor of organochlorine pesticides accumulation in adipose tissue.

Levels of organochlorine pesticides residues in human adipose tissue, data from Tabasco, Mexico

The objective of this study was to determine the levels of organochlorine pesticides HCB, α-β-γ-HCH, p,p'-DDE, o,p'-DDT and p,p'-DDT in 150 adipose tissue of inhabitants of Tabasco, Mexico. The following pesticides were detected: p,p'-DDE in 100% of samples at mean 1.034 mg/kg; p,p'-DDT in 96.7% at mean 0.116 mg/kg; o,p'-DDT in 78.7% at mean 0.022 mg/kg and β-HCH in 58.0% at mean 0.049 mg/kg. The pooled sample was divided according to sex of donors (75 female and 75 male). Significantly higher levels of all organochlorine pesticides in females were found. The sample was divided into three age's ranges (15-28, 29-45 and 46-84 years). The mean and median levels of β-HCH, p,p'-DDE and Σ-DDT increase significantly (p < 0.05) from the first to the second and third group. The presence of organochlorine pesticide residues in Tabasco inhabitants is still observed, indicating sources of exposure to the pesticides.

Organochlorine pesticide residue levels in blood serum of inhabitants from Veracruz, Mexico

The objective of the present study was to monitor the levels of organochlorine pesticides HCB; α-, β-, γ-HCH; pp'DDE; op'DDT; and pp'DDT in blood serum of Veracruz, Mexico inhabitants. Organochlorine pesticides were analyzed in 150 blood serum samples that constituted that which remained after clinical analyses, using gas chromatography-electron-capture detection (GC-ECD). The results were expressed as milligrams per kilogram on fat basis and micrograms per liter on wet weight. Only the following pesticides were detected: p,p'-DDE was the major organochlorine component, detected in 100% of samples at mean 15.8 mg/kg and 8.4 μg/L; p,p'-DDT was presented in 41.3.% of monitored samples at mean 3.1 mg/kg and 1.4 μg/L; β-HCH was found in 48.6% of the samples at mean 4.9 mg/kg and 2.7 μg/L; op'DDT was determined to be in only 3.3% of monitored samples at mean 2.7 mg/kg and 1.4 μg/L. The pooled samples divided according to sex showed significant differences of β-HCH and pp'DDE concentrations in females. The samples grouped according to age presented the third tertile as more contaminated in both sexes, indicating age as a positively associated factor with serum organochlorine pesticide levels in Veracruz inhabitants.

Organochlorine pesticide levels in female adipose tissue from Puebla, Mexico

The objective of this study was to determine the levels of organochlorine pesticides HCB, α-β-γ-HCH, pp'DDE, op'DDT and pp'DDT in adipose tissue of females living in Puebla, Mexico. Organochlorine pesticides were analyzed in 75 abdominal adipose tissue samples taken during 2010 by autopsy at the Forensic Services of Puebla. The results were expressed as mg/kg on fat basis. In analyzed samples the following pesticides were detected: p,p'-DDE in 100% of samples at mean 1.464 mg/kg; p,p'-DDT in 96.0.% of samples at mean 0.105 mg/kg; op'DDT in 89.3% of monitored samples at mean 0.025 mg/kg and β-HCH in 94.7% of the samples at mean 0.108 mg/kg. To show if organochlorine pesticide levels in monitored female's adipose tissues are age dependant, the group was divided in three ages ranges (13-26, 26-57 and 57-96 years). The mean and median levels of all organochlorine pesticides increase significantly (p < 0.05) from the first to second and from the first to third group. At the same time, the increase of mean and medians levels from the second to third group were not statistically significant (p > 0.05). The present results compared to previous ones from 2008 indicates an increase in the concentrations during the 2010 study, but only the differences for pp'DDE and op'DDT were statistically significant. The 2010 group of females was older compared to the 2008 group. The presence of organochlorine pesticide residues is still observed, indicating uniform and permanent exposure to the pesticides by Puebla inhabitants.

Monitoring of organochlorine pesticide residue levels in adipose tissue of Veracruz, Mexico inhabitants

The objective of the present study was to monitor the levels of organochlorine pesticides HCB, α-β-γ-HCH, pp'DDE, op'DDT and pp'DDT in 150 adipose tissue samples of Veracruz, Mexico inhabitants. In analyzed samples, the following pesticides were detected: p,p'-DDE in 100% of the samples at mean 1.643 mg/kg; p,p'-DDT in 99.3.% of the samples at mean 0.227 mg/kg; β-HCH in 97.3% of the samples at mean 0.063 mg/kg; and op'DDT in 93.3% of the samples at mean 0.022 mg/kg. Comparing mean, median and geometric mean concentrations of organochlorine pesticides shows a decrease in values from mean to median and to geometric mean which points out a prevalence of lower concentrations among the total samples and the existence of occasional cases of extreme exposure expressed in range values. The pooled samples divided according to sex, showed only significant differences of pp'DDE median concentrations between sexes. The other organochlorine pesticides indicated no statistical differences between sexes, including the pp'DDE/pp'DDT ratio. The samples grouped according to age, showed that the third tertile was more contaminated for both sexes, indicating age as a positively associated factor with organochlorine pesticide levels in adipose tissue of Veracruz inhabitants. Comparing organochlorine pesticide levels between 2008 and 2010 years, a decreased tendency for β-HCH, pp'DDE, Σ-DDT and pp'DDE/pp'DDT ratio levels was observed.

Circadian nursing induces PER1 protein in neuroendocrine tyrosine hydroxylase neurones in the rabbit doe

Rabbit does nurse their pups once a day with circadian periodicity and pups ingest up to 35% of their body weight in milk in < 5 min. In the doe, there is a massive release of prolactin. We hypothesised that periodic suckling synchronises dopaminergic populations that control prolactin secretion. We explored this by immunohistochemical colocalisation of PER1 protein, the product of the clock gene Per1 on tyrosine hydroxylase (TH) cells in three dopaminergic populations: tuberoinfundibular dopaminergic (TIDA), periventricular hypophyseal dopaminergic (PHDA) and incertohypothalamic dopaminergic (IHDA) cells. PER1/TH colocalisation was explored every 4 h through a complete 24-h cycle at postpartum day 7 in does that nursed their pups either at 10.00 h (ZT03) or at 02.00 h (ZT19; ZT0 = 07.00 h, time of lights on). Nonpregnant, nonlactating females were used as controls. In control females, there was a rhythm of PER1 that peaks at ZT15. By contrast, in nursed does, the PER1 peak shifted in parallel to scheduled nursing in TIDA and PHDA cells but not in IHDA cells, which are not related to the control of prolactin. Next, we determined that the absence of suckling for 48 h significantly decreases the number of PER1/TH colocalised cells in PHDA but not TIDA cells. Locomotor behaviour in control subjects was maximal at around the time of lights on but, in nursed females, shifted at around the time of scheduled nursing. Finally, in the suprachiasmatic nucleus, there is a maximal expression of PER1 at ZT11 in the three groups. However, this maximal expression was significantly lower in the nursed groups in relation to the control group and in the groups deprived of nursing for 48 h. We conclude that suckling synchronises dopaminergic cells related to the control of prolactin and appears to be a nonphotic stimulus for the suprachiasmatic nucleus.

Ciprofibrate versus gemfibrozil in the treatment of mixed hyperlipidemias: an open-label, multicenter study

Mixed hyperlipidemia is a common risk factor for cardiovascular disease. The aim of this trial was to evaluate the efficacy and safety of ciprofibrate versus gemfibrozil for the treatment of patients with mixed hyperlipidemia carefully selected for similar lipid profiles. A total of 68 patients who had mixed hyperlipidemia after following an isocaloric American Heart Association (AHA) phase I diet for 4 weeks were included. The plasma lipid levels at the inclusion were low-density lipoprotein-cholesterol (LDL-C) > or = 130 mg/dL, cholesterol > or = 240 mg/dL, and triglycerides > or = 200 mg/dL. Patients were randomly assigned to receive ciprofibrate 100 mg/d or gemfibrozil 1,200 mg/d. At the end of the 8-week treatment period, efficacy and safety parameters were compared with baseline values. The primary efficacy parameters of the study were percentage changes in triglycerides and LDL-C from baseline. After 8 weeks, plasma triglyceride concentrations were decreased by 43.5% and 54% compared with baseline during ciprofibrate and gemfibrozil therapy, respectively (P <.001). High-density lipoprotein-cholesterol (HDL-C) concentrations were increased 20.8% and 19.3% during ciprofibrate and gemfibrozil, respectively (P <.001). Apoprotein B, cholesterol, and very-low-density lipoprotein-cholesterol (VLDL-C) concentrations were also improved by the study drugs (18.6%, 13.2%, and 30.9%, respectively, during ciprofibrate and 44%, 13.8%, and 14.4%, respectively, during gemfibrozil). Meanwhile, the effect of the drug was minimal on LDL-C. A significant decrease in non-HDL-C resulted from both treatments (19% and 19.5%, respectively, P <.05). The only statistically significant difference observed between treatments was the effects on fibrinogen concentration, a coronary risk factor. Ciprofibrate significantly decreased its concentration by 18.8%, fibrinogen was slightly increased during gemfibrozil treatment. No patient had a significant modification on any of the safety tests. In summary, ciprofibrate and gemfibrozil are well-tolerated and efficacious treatments for mixed hyperlipidemia. Significant reductions in triglycerides, non-HDL-C, and apolipoprotein B were achieved with both drugs. A significant fibrinogen reduction was obtained with ciprofibrate.

Test-retest reliability of the alcohol and drug use disorder sections of the schedules for clinical assessment in neuropsychiatry (SCAN)

This report presents the results of a test-retest reliability study of the alcohol and drug dependence, as well as harmful use/abuse were investigated in Ankara, Turkey and Farmington, Connecticut (US). Reliabilities for the past year, prior to past year, and lifetime diagnosis of alcohol and drug use disorders were evaluated using ICD-IO, DSM-III-R and DSM-IV criteria. The results indicate that SCAN alcohol and drug diagnosis have good to excellent levels of reliability for dependence across different substances, different diagnostic systems, and different cultural groups. Diagnostic classification of alcohol and drug abuse/harmful use was considerably less reliable. Implications of the findings are discussed.

Elevated rates of early discontinuation from pharmacotherapy trials in alcoholics and drug abusers

The failure of subjects to complete clinical trials is a common problem with important implications for the interpretation of study results. Although a substantial literature exists on the high prevalence of premature termination from psychiatric and substance abuse treatment setting, there has been little attention paid to early discontinuation in clinical trials. There is evidence that the presence of substance abuse predicts higher rates of early discontinuation. This, combined with a recent increase in efforts to develop medications for treatment of substance use disorders, led us to conduct a literature review to determine whether pharmacotherapeutic trials for patients with these disorders have higher rates of premature discontinuation than comparable studies of patients with other psychiatric disorders. Of 267 articles that were initially identified, 83 met predetermined criteria for inclusion in the analysis. As hypothesized, after controlling for a number of potential contributing variables, treatment trials with substance abuse patients showed a significantly poorer retention rate than those of patients with other psychiatric diagnoses. The difference in retention rate was also evident when studies specific to alcohol dependence, the largest subgroup of substance use disorders, were evaluated separately. Although the retrospective nature of the study design limits the conclusions that can be drawn, the results suggest that, in pharmacotherapy trials with alcoholics or other substance abuse patients, particular attention should be paid to enhancing treatment retention.

Gestational diabetes in a Mexican-U.S. border population: prevalence and epidemiology

OBJECTIVE

To determine the prevalence of gestational diabetes (GD) in a Mexican-U.S. border population and to observe the response of such a population to a 100 gram challenge of glucose.

RESEARCH DESIGN AND METHODS

The sample was a cross section of 519 pregnant women accesing different health institutions in Juarez, Mexico, with 24-36 weeks of gestation. An oral glucose tolerance test (OGTT) with a 100 gram challenge of glucose was done on all. Results were interpreted according to the diagnostic criteria of O'Sullivan and Mahan. Information on family history of diabetes, obstetric history, height and weight was obtained.

RESULTS

A total of 20.4% of the patients examined had some kind of glucose intolerance 11% with GD and 9.4% with one abnormal value during the glucose tolerance test. The patients with GD tended to be older, had higher gravidity, lower height, higher weight and reported frequently a family history of diabetes. The patients with one abnormal value were similar to those with GD in weight and number of pregnancies, and were comparable to the group with normal glucose tolerance test in height and family history of diabetes.

CONCLUSIONS

We found a high prevalence of GD and of one abnormal value during the OGTT in a Mexican population. The recommendations for screening for GD must be consistently implemented in pregnant women of Mexican ancestry.

SP-303, an antiviral oligomeric proanthocyanidin from the latex of Croton lechleri (Sangre de Drago)

SP-303, a large proanthocyanidin oligomer isolated from the latex of the plant species Croton lechleri (Eupborbiaceae) has demonstrated broad activity against a variety of DNA and RNA viruses. In cell culture, SP-303 exhibits potent activity against isolates and laboratory strains of respiratory syncytial virus (RSV), influenza A virus (FLU-A) and parainfluenza virus (PIV). Parallel assays of SP-303 and ribavirin showed comparable activity against these viruses. SP-303 also exhibits significant inhibitory activity against herpesvirus (HSV) types 1 and 2, including herpesviruses resistant to acyclovir and foscarnet. Inhibition was also observed against hepatitis A and B viruses. The antiviral mechanism of SP-303 seems to derive from its direct binding to components of the viral envelope, resulting in inhibition of viral attachment and penetration of the plasma membrane. Antiviral effects of SP-303 were measured by three distinct methods: CPE, MTT and precursor uptake/incorporation. Cytotoxicity endpoints were markedly greater than the respective antiviral endpoints. SP-303 exhibited activity in RSV-infected cotton rats and African green monkeys, PIV-3-infected cotton rats, HSV-2 infected mice and guinea pigs and FLU-A-infected mice. The most successful routes of SP-303 administration for producing efficacy were: topical application to HSV-2- genital lesions in mice and guinea pigs, aerosol inhalation to FLU-A-infected mice and PIV-3-infected cotton rats, and oral dosage to RSV-infected cotton rats. A variety of toxicological evaluations demonstrated the safety of SP-303, particularly orally, which was predictable, since condensed tannins are a common dietary component. It is notable that the larger proanthocyanidins as a class have high antiviral activity, whereas most of the monomers are inactive. Clinical trials are ongoing to evaluate SP-303 as a therapeutic antiviral agent.

[Pseudocyesis: clinical and hormonal evaluation]

Hormonal and clinical evaluation was performed in eleven females with diagnosis of pseudocyesis. Plasma levels of pituitary gonadotropins (FSH-LH), progesterone, estradiol and thyroid hormones (T3, T4, TSH) under basal conditions were measured through radioimmunoassay. Diagnosis of pseudocyesis was made according to the following criteria: a) secondary amenorrhea (greater than 12 weeks); b) two or more symptoms of gestation; c) conviction of being pregnant; d) negative HCG or pelvic ultrasound study. The circulation levels of gonadotropins were within normal limits. Progesterone exhibited a ovulatory pattern and thyroid hormones were normal for every instance. Once case had slight hyperprolactinemia (26.0 ng/ml) with impaired gonadotropin production and ovulatory progesterone. All patients had galactorrhea. The psychological study disclosed a tendency toward depression. Our findings partially confirmed previous observations, differing basically on that we observed normal hormonal trend.