Detection of flea‑borne Rickettsia species in the Western Himalayan region of India.

Human infections by various rickettsial species are frequently reported globally. We investigated a flea‑borne rickettsial outbreak infecting 300 people in Western Himalayan region of India. Arthropod vectors (ticks and fleas) and animal and human blood samples from affected households were analysed by gltA and ompB genes based polymerase chain reaction (PCR). Rat flea (Ceratophyllus fasciatus) samples were found harbouring a Rickettsia sp. Phylogenetic analysis based on gltA gene using PHYLIP revealed that the detected Rickettsia sp. has 100% identity with SE313 and RF2125 strains of Rickettsia sp. of flea origin from Egypt and Thai‑Myanmar border, respectively and cf1 and 5 strains from fleas and lice from the USA. But, the nucleotide sequence of genetically variable gene ompB of R14 strain was found closely related to cf9 strain, reported from Ctenocephalides felis fleas. These results highlight the public health importance of such newly discovered or less recognised Rickettsia species/strains, harboured by arthropod vectors like fleas.

An experimental study on cardiotoxicity of aluminium phosphide.

Aluminium phosphide(AlP), a grain fumigant pesticide, was studied for its cardiotoxicity in anaesthetised rats. The hemodynamic and cardiac biochemical changes were investigated following intragastric administration of different doses of AlP (10, 20 and 40 mg). With 10 and 20 mg dose of AlP an immediate fall in BP was observed which recovered partially and stabilized for 10 minutes followed by a gradual fall till the animal died. However, with a higher dose (40 mg) there was no recovery in BP, instead the initial fall continued till the death of the animal. An increase in the heart rate was observed with 10 and 20 mg dose of AlP for 15 minutes which was followed by a marked fall till cardiac arrest ensued. On the other hand, 40 mg dose produced only a transient tachycardia followed by a prolonged bradycardia. ECG changes at all dose levels included initial tachycardia and ST segment elevation progressing to QRS broadening. However, marked conduction defects as evidenced by the ventricular ectopics were noticed only with 40 mg. The mean survival time dose dependently decreased with 10 mg(55 +/- 3 min), 20 mg(35 +/- 2 min) and 40 mg(18 +/- 2 min) of AlP. The cardiac glycogen, ATP and CP levels were significantly lowered in animals treated with 10, 20 and 40 mg of AlP. Higher levels of MDA in the cardiac tissue were observed with 10, 20 and 40 mg of AlP. Thus it is suggested that the deleterious effect of AlP on heart is mediated by both declined cellular metabolism of the myocardium as well as by necrosis of the cardiac tissue resulting in the release of reactive oxygen intermediates.

Fine needle aspiration cytology in the diagnosis of mediastinal seminomas.

Fine needle aspiration cytology (FNAC) was employed to diagnose 117 cases of mediastinal tumours from January, 1985 till December, 1994. Six cases were diagnosed as mediastinal seminomas which are rare mediastinal malignant neoplasms. All patients had complete resolution of the mediastinal masses after external beam radiotherapy. Diagnosis of mediastinal masses by FNAC can spare the patients from more invasive diagnostic procedures and help the thoracic surgeons to plan immediate treatment.

The surgical treatment of atrial myxomas. Clinical experience and results in eight patients.

Between 1983 and 1988, eight patients underwent excision of left atrial myxomas at the Institute of Postgraduate Medical Education & Research, Calcutta. There were five females and three males. The presenting symptoms and signs often simulated mitral stenosis or insufficiency, and the diagnosis was confirmed by echocardiography and angiocardiography. One patient presented with features of cerebral embolism. The myxomas were successfully removed under cardiopulmonary bypass in all patients, either by shaving them from the atrial septum, or by excising a portion of normal atrial septum with the tumour. Small tumours were removed through left atriotomy, while a biatrial approach was utilised for large tumours. There was one perioperative death, and another patient died one and half years later, probably due to tumour embolisation in brain. Late functional results have been excellent in all the other patients. Two dimensional echocardiography has proved to be extremely accurate in early diagnosis of myxomas and in the late follow up of patients. The pertinent literature is reviewed.