Solid phase microextraction: measurement of volatile organic compounds (VOCs) in Dhaka City air pollution

A solid phase microextraction (SPME) technique was applied for the sampling of volatile organic compounds (VOCs) in ambient air polluted by two stroke autorickshaw engines and automobile exhausts in Dhaka city, Bangladesh. Analysis was carried out by capillary gas chromatography (GC) and GC-mass spectrometry (MS). The methodology was tested by insitu sampling of an aromatic hydrocarbon mixture gas standard with a precision of +/-5% and an average accuracy of 1-20%. The accuracy for total VOCs concentration measurement was about 7%. VOC's in ambient air were collected by exposing the SPME fiber at four locations in Dhaka city. The chromatograms showed signature similar to that of unburned gasoline (petrol) and weathered diesel containing more than 200 organic compounds; some of these compounds were positively identified. These are normal hydrocarbons pentane (n-C5H2) through nonacosane (n-C29H60), aromatic hydrocarbons: benzene, toluene, ethylbenzene, n-propylbenzene, n-butylbenzene, 1,3,5-trimethylbenzene, xylenes, and 1-isocyanato-3-methoxybenzene. Two samples collected near an autorickshaw station contained 783000 and 1479000 microg/m3 of VOCs. In particular, the concentration of toluene was 50-100 times higher than the threshold limiting value of 2000 microg/m3. Two other samples collected on street median showed 135000 microg/m3 and 180000 microg/m3 of total VOCs. The method detection limit of the technique for most semi-volatile organic compounds was 1 microg/m3.

Randomized prospective study of outcome of short term antiepileptic treatment in small single enhancing CT lesion in brain

The study was conducted in 81 patients of epilepsy with small single enhancing CT (SSECT) lesion in brain to determine the clinical profile and duration of antiepileptic drugs (AEDs) treatment. The patients were randomly divided into group A (41 cases) and group B (40 cases). Group A patients were treated for 6 months and group B for 1 year with AEDS without cysticidal drugs. The most common mode of presentation was simple partial motor seizures with secondary generalization in both the groups. Repeat imaging of brain (CT/MRI) at 6 months showed disappearance of lesion in 82.94% in group A and 87% in group B, while persistence of lesion was present only in 4.87% in group A and 5% in group B. 87.81% patients in group A and 87.17% in group B were seizure free. The recurrence of seizure occurred in 12.19% cases in group A, and 12.82% in group B. 80% of these patients had calcified lesion in both the groups. This study reveals that SSECT lesion with epilpesy is a benign self-limiting disease. It also reveals that 6 months AED treatment is as effective as one year treatment. Patients having calcified lesion or persistence of lesion might require long term AED treatment.

Synthesis of Au nanoparticle-conductive polyaniline composite using H2O2 as oxidising as well as reducing agent

We report a new method of synthesis of an Au nanoparticle-conductive polyaniline composite by using H2O2 both for reduction of HAuCl4 and polymerization of aniline in the same aqueous medium: the electrical conductivity of the composite has been measured to be two orders of magnitude higher than the polymer itself.

Gastro-duodenal mucosal changes associated with low-dose aspirin therapy: a prospective, endoscopic study

OBJECTIVES

The association of low-dose aspirin use and gastro-intestinal bleeding is well described. However, the gastroduodenal mucosal changes associated with low-dose aspirin therapy have not been properly evaluated. We undertook a prospective, endoscopic study to evaluate gastro-duodenal mucosal lesions produced by low-dose aspirin.

METHODS

Forty-seven patients with non-hemorrhagic cerebral infarct or transient ischemic attacks and normal upper gastrointestinal endoscopy were randomized to receive either enteric-coated (n=25) or plain (n=22) aspirin (150 mg/day). Follow-up endoscopy was done at 2, 4 and 8 weeks; gastro-duodenal mucosal lesions, if present, were scored. Forty-seven patients with hemorrhagic infarct who were not treated with aspirin served as controls.

RESULTS

Twenty eight (60%) of 47 patients receiving aspirin had mucosal lesions; stomach alone was the most frequent site (32%), followed by both stomach and duodenum (23%). Frequency of mucosal changes in the stomach at 8 weeks (19%) was significantly lower (p<0.05) than those at 2 weeks (53%) and 4 weeks (55%). Coated (56%) and plain (63.6%) aspirin induced mucosal lesions with similar frequency.

CONCLUSION

Administration of low-dose aspirin, either plain or enteric-coated, induces endoscopic gastro-duodenal mucosal lesions in a large majority of patients. The frequency of damage decreased after 8 weeks of therapy.

Reversible posterior leukoencephalopathy syndrome: a report of 2 cases

Reversible posterior leukoencephalopathy syndrome (RPLE) is an increasingly recognised disorder, most commonly associated with malignant hypertension, toxaemia of pregnancy or the use of immunosuppressive agents. Two cases of RPLE syndrome occurring in the setting of accelerated hypertension and eclampsia are described. Both patients had seizures, altered sensorium and typical findings on neuroimaging. They had complete clinical and radiological recovery. The clinical course, pathophysiology and neuroimaging features of RPLE syndrome are discussed.

Estimation of mortality and morbidity due to strokes in India

In order to control the stroke problem, its magnitude should be assessed. India is ranked among the countries where the information on stroke is minimal. We decided to review the information available in order to estimate the mortality and morbidity due to stroke in India. Information was collected through electronic search, hand search and contact with experts. Each article was reviewed for relevance and epidemiological rigor. The demographic data were as derived from published government figures. The prevalence from individual studies was pooled and weighted based on sample size. Analysis was done separately for males and females at 10-year intervals (20 years onwards). A total of 7 studies was located, but 2 were discarded. All were done in rural areas except 2 which also included urban areas. The prevalence was estimated as 203 per 100,000 population above 20 years amounting to a total of about 1 million cases. The male to female ratio was 1.7. Around 12% of all strokes occurred in population below 40 years. The estimation of stroke mortality was seriously limited by the method of classification of cause of death in the country. The best estimate derived was 102,000 deaths; which represented 1.2% of total deaths in the country. There is need to initiate steps to collect data on morbidity and mortality due to stroke in the country as a first step towards control measures.

Axonal Guillain-Barré syndrome: a critical review

Axonal Guillain-Barré Syndrome (GBS) was first described by Feasby et al. in 1986, challenging the existent notion of GBS being a primarily demyelinating disease. The severe course and slow recovery commonly seen in these patients was ascribed to axonal degeneration. Other authors challenged this claim on several grounds. Amidst these controversies, epidemics of a similar illness were reported from China, which were given the acronym AMAN, having exclusive motor involvement in contrast to the cases already described in which both motor and sensory involvement were present (AMSAN). Pathologically, Wallerian degeneration, minimal lymphocytic response, absent demyelination or inflammation and periaxonal macrophages are prominent features. Ultrastructural studies have revealed node of Ranvier to be the prime target of immune attack. A frequent occurrence of antecedent Campylobacter jejuni infection and a strong association between elevated titres of IgG GM1 and axonal GBS on a background of preceding C. jejunii infection has been observed and molecular mimicry between lipopolysaccharides of C. jejuni and neural epitopes has been proposed as a mechanism of injury. Clinically axonal variant is similar to AIDP, but a more severe course, with frequent respiratory involvement, ventilator dependence and significant residue may be seen. Diagnosis is essentially electrophysiological. Treatment is similar to AIDP, preferential benefit of either IVIG or plasmapheresis needs to be further evaluated. A critical review of existing literature in axonal GBS is presented.

Congenital myasthenic syndrome: report of four cases and brief review of literature

The term 'congenital myasthenic syndrome' (CMS) encompasses a number of heterogeneous disorders characterised by myasthenic symptoms since birth, usually with positive family history and absence of acetyl choline receptor antibodies. Recent advances in electrophysiology and ultrastructural analysis of neuromuscular junction have made it possible to identify the various defects underlying these disorders. We report four cases of CMS, with a review of literature.

Usefulness of triiodothyronine (T3) treatment after surgery for complex congenital heart disease in infants and children

This is a study of the use of T3 infusion in the postoperative period in 6 pediatric patients who underwent complex cardiac surgical procedures under cardiopulmonary bypass. Normalization of serum T3 levels was reflected in a marked decrease in requirement of inotropic support, conversion to normal sinus rhythm, and progressively improving clinical course.

Periodicity-dependent stiffness of periodic hydrophilic-hydrophobic heteropolymers

From extensive Monte Carlo simulations of a Larson model of perfectly periodic heteropolymers (PHP) in water, a striking stiffening is observed as the period of the alternating hydrophobic and hydrophilic blocks is shortened. At short period and low temperature needlelike conformations are the stable conformations. As temperature is increased thermal fluctuations induce kinks and bends. At large periods compact oligomeric globules are observed. From the generalized Larson prescription, originally developed for modeling surfactant molecules in aqueous solutions, we find that the shorter the period is the more stretched the PHP is. This novel effect is expected to stimulate polymer synthesis and trigger research on the rheology of aqueous periodic heteropolymer solutions.

Couple-friendly services in a metropolitan sexually transmitted disease clinic: views of clients and providers

CONTEXT

Clients making clinic visits related to reproductive health might benefit from participation with their partner. There is little information available, however, on whether either clients themselves or clinic staff would feel comfortable with such a possibility.

METHODS

The Multnomah County Health Department Sexually Transmitted Disease Clinic in Portland, Oregon, conducted a survey of 237 new clients in June 1994 to assess clients' and providers' responses to the idea of offering couple visits.

RESULTS

Twenty-six percent of female clients and 16% of male clients were accompanied by their partner on their visit to the clinic. Eighty-seven percent of all clients favored the clinic's offering couple visits, 5% opposed the concept and 8% were undecided. Fifty-four percent would have wanted their partner to be with them during their present visit if this choice had been offered, and 62% would want their partner to join them in follow-up couple visits if this were recommended by their provider. Seventy-one percent had already discussed with their partner the reason for their immediate clinic visit, and 88% expected to discuss the visit with their partner afterward. Attitudes toward couple services were similar for male and female clients and did not vary by race or ethnicity. For more than one-fifth of clients, clinic staff reported that they would not recommend couple visits; however, many of these clients reported that they would prefer being accompanied by their partner.

CONCLUSIONS

Appropriately designed couple-friendly options are likely to be generally accepted and moderately utilized by clients of varying backgrounds. Clinic staff may be more reluctant to involve clients' partners than the clients are themselves, however.

Distinct functions of eukaryotic translation initiation factors eIF1A and eIF3 in the formation of the 40 S ribosomal preinitiation complex

We have used an in vitro translation initiation assay to investigate the requirements for the efficient transfer of Met-tRNAf (as Met-tRNAf.eIF2.GTP ternary complex) to 40 S ribosomal subunits in the absence of mRNA (or an AUG codon) to form the 40 S preinitiation complex. We observed that the 17-kDa initiation factor eIF1A is necessary and sufficient to mediate nearly quantitative transfer of Met-tRNAf to isolated 40 S ribosomal subunits. However, the addition of 60 S ribosomal subunits to the 40 S preinitiation complex formed under these conditions disrupted the 40 S complex resulting in dissociation of Met-tRNAf from the 40 S subunit. When the eIF1A-dependent preinitiation reaction was carried out with 40 S ribosomal subunits that had been preincubated with eIF3, the 40 S preinitiation complex formed included bound eIF3 (40 S.eIF3. Met-tRNAf.eIF2.GTP). In contrast to the complex lacking eIF3, this complex was not disrupted by the addition of 60 S ribosomal subunits. These results suggest that in vivo, both eIF1A and eIF3 are required to form a stable 40 S preinitiation complex, eIF1A catalyzing the transfer of Met-tRNAf.eIF2.GTP to 40 S subunits, and eIF3 stabilizing the resulting complex and preventing its disruption by 60 S ribosomal subunits.