Leber's hereditary optic neuropathy with molecular characterization in two Indian families.

PURPOSE: Leber's hereditary optic neuropathy (LHON) presents in early adulthood with painless progressive blindness of one or both eyes. Usually there is a positive family history of similar disease on the maternal side. Definitive diagnosis can be established by finding the change in the mitochondrial gene. No molecular studies have been reported from India. MATERIAL AND METHODS: Clinical, ophthalmologic and molecular studies were carried out in two patients from different families and available first degree relatives. The subjects were tested for the three common mutations seen in LHON by molecular techniques of polymerase chain reaction using mutation specific primers. RESULTS: The mutations G3460A and G11778A in the mitochondrial genes MTND1 and MTND4, known to be causative for LHON, were found in one family each. CONCLUSION: Diagnosis of LHON should be considered in familial cases and in young adults with optic atrophy. Confirmation of diagnosis should be sought by molecular gene analysis. Genetic counselling should be offered to all 'at risk' relatives of a patient harbouring the mutation.

Prehospital delay in patients hospitalized with acute myocardial infarction in the emergency unit of a North Indian tertiary care hospital.

BACKGROUND: Prompt treatment of patients presenting with acute myocardial infarction decreases the incidence of death from early arrhythmia, and maximizes the potential benefit of thrombolytic therapy. Prehospital delay has been identified as a major obstacle to the widespread use of thrombolytic therapy. The aim of the present study was to examine the extent of, and factors associated with, delay in seeking medical care (usually thrombolytic therapy) in patients with acute myocardial infarction. METHODS AND RESULTS: The study was conducted in patients visiting the medical emergency unit of the Nehru Hospital, Post Graduate Institute of Medical Education and Research, Chandigarh. A total of 104 patients diagnosed with acute myocardial infarction were interviewed using a pre-designed proforma. Pain-to-door, and door-to-drug times, were the main outcome measures. The corrected mean (SEM) and median (range) pain-to-door times were 8.5 (0.8) hours and 5.2 (0.5-24) hours, respectively. Out of 104 patients, 38 did not receive thrombolytic therapy. In those who did not receive thrombolytic therapy, prior therapy at local health centers, lack of knowledge of symptoms, and transportation problems were the main reasons for hospital delay. The mean (SEM) and median (range) of door-to-drug times were 1.2 (0.1) hours and 1 (0.2-3.5) hours, respectively.

A cardiac evoked response algorithm providing automatic threshold tracking for continuous capture verification: a single-center prospective study.

BACKGROUND: The AutoCapture algorithm as implemented in Regency and Microny pacemakers (Pacesetter Inc., Sylmar, CA, USA) provides beat-by-beat monitoring of capture based on proper detection of the evoked response, provides high output back-up pulse when loss of capture occurs, performs periodic threshold evaluations and acquires the capture threshold data in a time-based event counter for later retrieval. The safety and efficacy of this algorithm was prospectively evaluated at a tertiary care hospital of north India. METHODS AND RESULTS: Fifty-four patients (38 males, mean age 66+/-13 years) received a ventricular pacemaker model Regency SC+ with low polarization bipolar lead for high-grade atrioventricular block (n=42) and sick sinus syndrome (n=12). Evoked response and polarization signal were assessed initially at 24 hours postimplant, and follow-up measurements were systematically conducted at week 1 and months 1, 3 and 6. Further evaluation of eligible patients was performed at 6-monthly intervals. Lead implantation parameters were optimum in all patients. At 6 months, the algorithm was functional in 51 patients. The pacing threshold increased to 0.89+/-0.36 V (p<0.001) in the first month and stabilized thereafter. Significant saving of energy was accomplished by a constant output safety margin of 0.3 V instead of the traditional 100%. While the evoked response signal remained stable throughout the study period, the potential signal increased significantly from 0.6+/-0.7 mV to 1.0+/-0.6 mV (p<0.001) in the first month and remained steady subsequently. Back-up pacing in the event of exit block was confirmed in all 25 patients who underwent a 24-hour Holter test. Based on the suggested sense margins, ventricular undersensing was observed in 7 (28%) patients, the majority of whom had competitive cardiac rhythms. An elderly patient with pneumonic illness succumbed to pulmonary embolism at 6 months. CONCLUSIONS: This large single-center experience on AutoCapture demonstrates the success of this algorithm in low-energy ventricular pacing without compromising the patient's safety.

Secondary lymphoma of the heart presenting as recurrent syncope.

A 12-year-old male child presented with recurrent syncope. Ventricular tachycardia was noted on the electrocardiogram. Transthoracic echocardiogram revealed a homogeneous tumor mass in the right ventricular cavity with extension into the outflow region. Left cervical lymph node biopsy confirmed the diagnosis of non-Hodgkin's lymphoma. The tumor resolved completely with chemotherapy without surgical intervention.

A meta-analysis of controlled clinical trials comparing low-molecular weight heparins with unfractionated heparin in unstable angina.

BACKGROUND: Unfractionated heparin has been used extensively for the treatment of unstable angina/non-Q wave myocardial infarction but it has several disadvantages. Low-molecular weight heparins are now recommended although they are 3-5 times costlier than unfractionated heparin since they are convinient to administer and do not require activated thromboplastin time monitoring. Whereas enoxaparin, a low-molecular weight heparin, has been demonstrated to be superior to unfractionated heparin, the results of other low-molecular weight heparins have not been so convincing. METHOD AND RESULTS: Through manual, MEDLINE and EMBASE search, we identified five randomized trials (excluding enoxaparin trials) that compared low-molecular weight heparins with unfractionated heparin in unstable angina. The prespecified efficacy end point of interest included a composite of death, myocardial infarction, recurrent angina and urgent revascularization. The safety end point was taken as a composite of major hemorrhage, minor hemorrhage, thrombocytopenia, allergic reaction and any other adverse event. We calculated odds ratio (95% confidence interval) for each trial for the composite end point, and the pooled odds ratio (95%) confidence interval) was calculated using two established methods of meta-analysis, the Mantel-Haenszel-Peto method and the DerSirmonian-Laird method. Both the methods yielded similar odds ratio (95% confidence interval). Separate odds ratio were calculated for efficacy and safety end points. There was a nonsignificant reduction in the incidence of the composite efficacy end point: the odds ratio (95% confidence interval) was 0.83 (0.70-0.99: p=0.08). The odds ratio (95% confidence interval) for the safety data was 0.78 (0.69-1.26: p=0.33). CONCLUSIONS: No statistically significant difference was observed when the efficacy and safety of low-molecular weight heparins were compared with those of unfractionated heparin. A cost-effectiveness analysis of low-molecular weight heparins versus unfractionated heparin must be done urgently to establish more firmly the place of low-molecular weight heparins in the management of unstable angina.

Isolation and subcloning of chitinase clone from chickpea genomic library.

Chickpea genomic library constructed earlier in phage lambda (EMBL-3) was screened for the presence of chitinase clone using tobacco chitinase cDNA as a probe. Positive clones obtained by primary screening of plaques (2 x 10(6)) were ascertained by secondary and tertiary screening. Presence of chitinase insert in the positive clones obtained, was further confirmed by restricting phage DNA with Sal I and then doing southern with tobacco chitinase. The insert band was eluted out and subcloned in puc 19 plasmid.