Profile of beta-thalassemia in eastern India and its prenatal diagnosis

OBJECTIVE: To control the birth of thalassemic children in India. METHODS: Mutations present in the population of eastern India and in carrier parents seeking prenatal diagnosis were detected by the PCR-based technique of ARMS (amplification refractory mutation system) or gap-PCR. To screen for maternal tissue contamination in CVS, haplotypes associated with the beta-globin gene clusters were constructed using six polymorphic restriction sites. Prenatal diagnosis was accomplished by checking presence of parental mutation in the DNA from chorionic villus sampling (CVS) collected at 8 to 10 weeks' gestation by appropriate technique. RESULTS: Six hundred and fifty (650) unrelated beta-thalassemia chromosomes were screened for 11 common mutations to characterize the mutation distribution in this population. Starting from early 2000, 63 families from different parts of West Bengal and from surrounding areas have been offered prenatal counseling for beta-thalassemia. CONCLUSION: The population of this region is conscious and willing to accept prenatal diagnosis as a means of control of thalassemia.     

Cytogenetic damage and genetic variants in the individuals susceptible to arsenic-induced cancer through drinking water

In West Bengal, India, more than 300,000 arsenic-exposed people are showing symptoms of arsenic toxicity, which include cancers of skin and different internal organs. Since only 15-20% of the exposed population manifest arsenic-induced skin lesions, it is thought that genetic variation might play an important role in arsenic toxicity and carcinogenicity. A total of 422 unrelated arsenic-exposed subjects (244 skin-symptomatic and 178 asymptomatic) were recruited for this study. Cytogenetic damage, as measured by chromosomal aberrations in lymphocytes and micronuclei formation in oral mucosa cells, urothelial cells and binucleated lymphocytes, was studied in unexposed, skin-symptomatic and asymptomatic individuals with similar socioeconomic status. Identification of null mutations in GSTT1 and GSTM1 genes were carried out by PCR amplification. GSTP1 SNPs, implicated in susceptibility to various cancers, were assessed by PCR-RFLP method. Symptomatic individuals had higher level of cytogenetic damage compared to asymptomatic individuals and asymptomatic individuals had significantly higher genotoxicity than unexposed individuals. No difference in allelic variants in GSTT1 and GSTP1 was observed between these 2 groups. Incidence of GSTM1 null gene frequencies was significantly higher in the asymptomatic group. Individuals with GSTM1-positive (at least one allele) had significantly higher risk of arsenic-induced skin lesions (odds ratio, 1.73; 95% confidence interval, 1.24-2.22). These results show a protective role of GSTM1 null in arsenic toxicity. This study also indicates that asymptomatic individuals are sub clinically affected and are also significantly susceptible to arsenic-induced genotoxicity.     

Expression of fascin, an actin-bundling protein, in astrocytomas of varying grades

Malignant astrocytomas are highly infiltrative neoplasms that invade readily into regions of normal brain. On a cellular basis, the motility and invasiveness of human cancers can be ascribed in part to complex rearrangements of the actin cytoskeleton that are governed by several actin-binding proteins. One such actin-binding protein that has been linked to the invasive behavior of carcinomas is fascin, which serves to aggregate F actin into bundles. In this study, we examined the expression of fascin in a series of human malignant astrocytomas (WHO grades I–IV). Five grade I, 5 grade II, 10 grade III, and 26 grade IV human astrocytomas were examined for fascin and glial fibrillary acidic protein (GFAP) expression by double immunofluorescence confocal microscopy. Expression of fascin and GFAP was also determined by Western blot analysis. Fascin expression increased with increasing WHO grade of astrocytoma. This is in marked contrast to GFAP expression, which decreased with increasing WHO grade. In grades I and II neoplasms, and within non-neoplastic brain, fascin and GFAP were expressed diffusely within regions examined. However, in the higher-grade astrocytomas (grades III and IV), fascin and GFAP were expressed regionally in distinctly separate tumor cell populations. This is the first study to demonstrate the expression of fascin in human astrocytic neoplasms. The role that fascin plays in contributing to the invasive phenotype of anaplastic astrocytomas awaits further study and investigation.     

Anaesthesia-related maternal mortality

Complications of anaesthesia leading to death in young pregnant women might be prevented if more experienced personnel could be entrusted with the job. The contribution of anaesthesia to maternal mortality in the United Kingdom is 1.7 per million pregnancies with almost similar incidence from United States. The commonest single factor responsible for anaesthesia-related death is difficult or failed intubation. A pregnant woman with a potentially difficult airway should receive aspiration prophylaxis (mechanical or pharmacological) as soon as operative delivery is anticipated. Anaesthetists should make a plan that comes into effect as soon as failure to view the larynx or to intubate the trachea becomes evident. Unsuspected difficult airway can be managed if the skill of the anaesthetists is of high standard. Pulmonary aspiration is one cause of death in obstetric anaesthesia. Regurgitation and vomiting prevention can minimise pulmonary aspiration. In regional anaesthesia, local anaesthetics toxicity is another cause of concern. This should be tackled with some safe local anaesthetics. Preventing a high spinal or epidural block involves ways to detect inadvertent injection of local anaesthetic into the cerebrospinal fluid. Postoperative care after anaesthesia in obstetric cases is very important.     

Unilateral loss of vision following snakebite

A 14- year-old boy presented at the outpatients' department with the complaint of visual loss in the right eye of 1 1/2 months duration. He had the history of snakebite for which he was admitted to hospital. The diminution of vision started next day after snakebite. On examination, he had no perception of light in his right eye. USG B scan showed vitreous haemorrhage in his right eye. He was given IV methylpredinisolone. At follow-up after one month he still had no perception of light in his right eye with the haemorrhage in the vitreous subsided.     

Hepatitis B virus genotype D infection among antenatal patients attending a maternity hospital in Calcutta, India: assessment of infectivity status

A seroepidemiological study was conducted to determine the hepatitis B virus carrier rate and infectivity status among antenatal patients in Calcutta. Fifteen of 400 antenatal mothers (3.74%) were carriers of HBV genotype D. Four (1.0%) of them were positive for HBeAg with a high risk of transmitting infection to their babies. The presence of precore mutant HBV, which has been associated with transmission events from HBeAg mothers to their babies, was not detected in any of the HBeAg negative mothers.     

Ovarian neoplasms in adolescence and childhood--an analysis of twenty cases

Between January, 1999 and June, 2001 consecutive twenty cases of ovarian tumours in girls below 20 years of age admitted in Burdwan Medical College, Burdwan, West Bengal were analysed. Commonest presentation was lump abdomen (80%), 15% presented with acute abdomen, one patient presented with virilisation and another with precocious puberty and 85% had single ovarian involvement. Among 5 cases of torsion of ovarian tumours, one along with the twisted uterus was detected. Conservative surgery in the form of cystectomy or unilateral oophorectomy with or without salpingectomy was possible in 85% cases. Germ cell tumours (60%) took the leading place followed by epithelial (3 0%) and sex-cord stromal tumour (10%). Fifty percent neoplasms were malignant with majority (80%) being instage I. Combination chemotherapy was considered for 7 out of 10 cases. Conservative surgery in one hand and the fear of malignancy on the other are the real problems in these cases. Early detection, optimal therapy and intense follow-up are the key points of the management.     

Atypical presentation of a unilateral septic thrombosis of the cavernous sinus

A 7 year-old boy with unilateral septic cavernous sinus thrombosis following a pyoderma in the eyebrow is described. Problems in diagnosis and the role of magnetic resonance imaging (MRI) in the management are highlighted. Patient recovered with mild residual sequelae. The unique feature of this case was absence of chemosis and non-toxic presentation of the patient.