Association between mortality from suicide in England and antidepressant prescribing: an ecological study

Background

There are multiple studies in different countries regarding the prevalence of vitamin D deficiency. These studies showed high prevalence of vitamin D deficiency in Asian countries. This study tries to elucidate the prevalence of vitamin D deficiency and its influencing factors in population of Tehran.

Methods

1210 subjects 20–64 years old were randomly selected. 25 (OH) D serum levels were measured. Duration of exposure to sunlight, the type of clothing and level of calcium intake and BMI were quantified based on a questionnaire.

Results

A high percentage of vitamin D deficiency was defined in the study population. Prevalence of severe, moderate and mild Vitamin D deficiency was 9.5%, 57.6% and 14.2% respectively. Vitamin D serum levels had no significant statistical relation with the duration of exposure to sunlight, kind of clothing and BMI. Calcium intake in the normal vitamin D group was significantly higher than the other groups (714.67 ± 330.8 mg/day vs 503.39 ± 303.1, 577.93 ± 304.9,595.84 ± 313.6). Vitamin D serum levels in young and middle aged females were significantly lower than the older group.

Conclusions

Vitamin D deficiency has a high prevalence in Tehran. In order to avoid complications of vitamin D deficiency, supplemental dietary intake seems essential.     

Following in the footsteps of smallpox: can we achieve the global eradication of measles?

Background  

Although an effective measles vaccine has been available for almost 40 years, in 2000 there were about 30 million measles infections worldwide and 777,000 measles-related deaths. The history of smallpox suggests that achieving measles eradication depends on several factors; the biological characteristics of the organism; vaccine technology; surveillance and laboratory identification; effective delivery of vaccination programmes and international commitment to eradication.     

The Lathyrus excitotoxin beta-N-oxalyl-L-alpha,beta-diaminopropionic acid is a substrate of the L-cystine/L-glutamate exchanger system xc-

Beta-N-oxalyl-L-alpha-beta-diaminopropionic acid (beta-L-ODAP) is an unusual amino acid present in seeds of plants from the Lathyrus genus that is generally accepted as the causative agent underlying the motor neuron degeneration and spastic paraparesis in human neurolathyrism. Much of the neuropathology produced by beta-L-ODAP appears to be a direct consequence of its structural similarities to the excitatory neurotransmitter L-glutamate and its ability to induce excitotoxicity as an agonist of non-NMDA receptors. Its actions within the CNS are, however, not limited to non-NMDA receptors, raising the likely possibility that the anatomical and cellular specificity of the neuronal damage observed in neurolathyrism may result from the cumulative activity of beta-L-ODAP at multiple sites. Accumulating evidence suggests that system xc-, a transporter that mediates the exchange of L-cystine and L-glutamate, is one such site. In the present work, two distinct approaches were used to define the interactions of beta-L-ODAP with system xc-: Traditional radiolabel-uptake assays were employed to quantify inhibitory activity, while fluorometrically coupled assays that follow the exchange-induced efflux of L-glutamate were used to assess substrate activity. In addition to confirming that beta-L-ODAP is an effective competitive inhibitor of system xc-, we report that the compound exhibits a substrate activity comparable to that of the endogenous substrate L-cystine. The ability of system xc- to transport and accumulate beta-L-ODAP identifies additional variables that could influence its toxicity within the CNS, including the ability to limit its access to EAA receptors by clearing the excitotoxin from the extracellular synaptic environment, as well as serving as a point of entry through which beta-L-ODAP could have increased access to intracellular targets.     

The successful use of ALA-PDT in the treatment of recalcitrant molluscum contagiosum

Photodynamic therapy (PDT) with topical 5-aminolevulinic acid (ALA) has been shown to be safe and effective for a variety of skin concerns. The case report described is the first successfully documented use of ALA/PDT in the therapy of recalcitrant molluscum contagiosum in HIV-positive individuals.     

Differentiation of substrate and non-substrate inhibitors of transport system xc(-): an obligate exchanger of L-glutamate and L-cystine

In addition to the well-characterized sodium-dependent excitatory amino acid transporters (EAATs) present in the mammalian CNS, a chloride-dependent, sodium-independent transporter has also been identified that is capable of mediating the uptake of L-glutamate. Named system x(c)(-), this transporter is an obligate exchanger that normally couples the export of intracellular L-glutamate with the import of extracellular L-cystine. Two cell lines that express high levels of system x(c)(-) are used to delineate the pharmacology of the transporter and demonstrate that it is distinct from both the EAATs and EAA ionotropic receptors. Potent competitive inhibitors of system x(c)(-) include: L-homocysteate, ibotenate, L-serine-O-sulphate, (RS)-4-bromohomoibotenate, quisqualate, and (S)-4-carboxyphenylglycine. A fluorescent-based assay that allows system x(c)(-)-mediated exchange of L-glutamate and L-cystine to be followed in real time is used to assess substrate activity. Interestingly, those compounds that proved to be the most potent competitive inhibitors (e.g. L-quisqualate and 4-S-CPG) also proved to be the least active as substrates, suggesting that distinct structural features may control binding and translocation. Lastly, the finding that a number of system x(c)(-) inhibitors are also commonly used as probes of excitotoxic pathology (e.g., L-quisqualate, ibotenate and L-homocysteate) raises some interesting questions regarding the mechanisms through which these analogues produce CNS damage.     

A field test and comparison of acute and chronic sediment toxicity tests with the estuarine amphipod Leptocheirus plumulosus in Chesapeake Bay, USA

A 28-d partial life-cycle test with the estuarine amphipod Leptocheirus plumulosus was developed in response to the need for an assay to mimic chronic exposure to sediment-associated contaminants. To ensure that toxicity tests have environmental relevance, it is essential to evaluate the relationship between laboratory responses and field measures of contamination. Consequently, one objective of the study was to compare the results of the chronic sediment toxicity test with L. plumulosus to gradients of sediment contamination and the in situ benthic community in its native Chesapeake Bay. Chronic tests were conducted by two laboratories, the Army Corps of Engineers Waterways Experiment Station ([WES]; Vicksburg, MS, USA) and the University of Maryland ([UM] College Park, MD, USA) using different feeding regimes, providing the opportunity to evaluate the effect of this variable on response sensitivity. A second objective was to compare the relative sensitivity of acute and chronic tests with L. plumulosus with field-collected sediments. Overall, there was good agreement between the toxicological response of acute and chronic tests with L. plumulosus and field measures of contamination. Survival in the acute test and chronic test conducted by WES was negatively correlated with concentrations of sediment-associated contaminants. Survival in acute exposures was significantly reduced in sediments from 8 of 11 stations. Indigenous L. plumulosus were found only at two of the three stations that did not exhibit acute toxicity. An unexpected finding was the difference in responsiveness of the two chronic tests. Survival in tests conducted by UM and WES was significantly reduced in sediments from 4 and 6 of 11 stations, respectively. No additional sublethal toxicity was detected in the UM chronic test, but the WES test detected reproductive effects at two additional stations. We believe the observed differences were related to the test diet used. Partly as a result of our findings, the recommended diet for the L. plumulosus chronic test was changed in the final methods document.     

Incidence of occult rectal prolapse in patients with clinical rectoceles and defecatory dysfunction

OBJECTIVE: The purpose of this study was to determine the incidence of occult rectal prolapse (rectal intussusception) by defecating proctography in patients with clinical rectoceles and defecatory dysfunction. STUDY DESIGN: Patients who were seen from September 2000 through August 2001 with defecatory dysfunction and clinical rectoceles underwent single contrast defecating proctography. Radiologists who specialized in gastrointestinal fluoroscopy interpreted the results, which were retrieved from a computerized database.Study Design: Sixty patients who met the inclusion criteria were evaluated. Twenty patients (33%) had intussusception; 58 patients (97%) had rectocele; 1 patient (1.7%) had sigmoidocele, and 6 patients (10%) had anismus (paradoxic contraction of the puborectalis). RESULTS: All but 1 case of intussusception was associated with a rectocele radiographically. Anismus was associated with rectoceles radiographically, except in 1 patient for whom it was the sole finding. CONCLUSION: The data suggest a 33% incidence of occult rectal prolapse in patients with clinical rectoceles and defecatory dysfunction. This is highly clinically significant because one third of patients who are examined for defecatory dysfunction and rectocele may require sigmoid resection rectopexy along with other reconstructive procedures to restore pelvic floor function and prevent symptomatic recurrence.     

Monitoring arterial blood pressure: what you may not know

Hemodynamic monitoring is a costly procedure, both materially and with regard to nursing time involved to ensure proper functioning of the monitoring system and correct interpretation of the data obtained. Dynamic response testing is the ideal method of confirming the ability of a monitoring system to accurately reproduce hemodynamic waveforms. MAP is a stable hemodynamic parameter, because it is least affected by monitoring method, catheter insertion site, the dynamic response characteristics of the catheter system, and wave reflection. MAP provides the best estimate of central aortic pressure and is the main hemodynamic parameter monitored by the neurohormonal system to control blood pressure. The superior informational value of MAP provides strong support for its preferred use in clinical practice, especially when use of vasoactive drugs is started or the dosages of these drugs are titrated. However, numerically satisfactory ABP or MAP values are not necessarily related to adequate peripheral tissue perfusion and organ system function. For optimal management of patients, data obtained from assessment tools such as hemodynamic monitoring devices must be integrated with information gained from clinical assessment of patients' status.