An estimate of phylogenetic relationships among culicine mosquitoes using a restriction map of the rDNA cistron

Restriction maps of the rDNA cistron of twelve species of mosquitoes in six genera of the subfamily Culicinae were constructed using eight 6 bp recognition restriction enzymes. Anopheles albimanus was used as an outgroup. The size of the rDNA cistron ranged from 8.5 kb in Aedes katherinensis to 12.9 kb in Ae. polynesiensis. A total of twenty-six sites were scored; eighteen were polymorphic among ingroup taxa. The proportion of polymorphic nucleotide sites (Pnuc) was 0.059 and the heterozygosity per nucleotide site (Hnuc) was 0.028. Wagner and Fitch Parsimony, Dollo Parsimony and Nei-Li distance/neighbour-joining methods were used to construct phylogenetic trees. The rDNA RFLP dataset did not provide a well-supported phylogeny among culicine taxa. The RFLP phylogenies are incongruent with the morphology character based and molecular phylogenies and derived relationships did not correspond with current taxonomic classifications. The lack of resolution was due to homoplasy arising from frequent independent loss or gain of restriction sites among unrelated taxa.     

Results of penetrating keratoplasty in vascularized corneas.

A retrospective longitudinal study of 105 penetrating keratoplasties for vascularized corneal opacities was done. The results of cases with an etiology of healed trachoma or healed corneal ulcers were compared. The vascularization was graded from Grade I to V depending on the quadrant and type of vascularization. Graft clarity of 2+ or more in cases of trachomatous opacity was achieved in 93% of cases and that after postinfectious opacity in 71.8%. Prognosis was poor in cases where deep vascularization was present in more than two quadrants or more than 180 degrees.     

Destructive ocular myiasis in a noncompromised host

A case of destructive ocular myiasis resulting in complete loss of the globe in two days time is documented. To the best of our knowledge this is the first report of such a severe involvement in a healthy and non-compromised host. Mechanical removal and good local hygiene helped heal the wound. The larvae were isolated to be that of Chrysomyia bezziana (screwworm fly). This is possibly the first report of destructive ocular myiasis caused by Chrysomyia bezziana from the Indian subcontinent and the second in world literature. Infestation of human eyes with larvae of flies (myiasis) has been reported. Serious consequences of destructive myiasis are seen in emaciated and diseased patients. Only one report of total destruction of the globe by maggots of Chrysomyia bezziana exists in the literature. As in previous communications, the patient in this report had no predisposing factors both systemic and local. We here in document a case of orbital myiasis leading to rapid destruction of the globe within two days in a healthy and a non-compromised patient.     

Extended trans-septal approach for mitral valve surgery: Our early experience

Background Extended trans septal (ETS) approach for mitral valve surgery often divides the artery to the Sino-Atrial node. The clinical implication of this is contentious. We analyzed our early results with ETS approach. Methods Between June 1998 and September 2003 eleven patients underwent mitral valve surgery by ETS approach. Six were females. Age ranged from 19 years to 67 years (median 40 years). Six underwent mitral valve replacement (MVR). Four underwent aortic and mitral (double) valve replacement (DVR). One had mitral valve repair. Three had additional procedures (tricuspid valve repair=1, Coronary artery bypass=1, Aorto bifemoral graft=1). Cardiopulmonary bypass ranged from 64 minutes to 77 minutes (median 72 minutes) for MVR and 112 minutes to 178 minutes (median 140 minutes) for DVR. Aortic cross clamp times ranged from 39 minutes to 52 minutes (median 47 minutes) for MVR and 74 minutes to 120 minutes (median 95 minutes) for DVR. Results There was no mortality or morbidity attributed to the ETS approach. One early death in emergency DVR was due to heart failure. Three patients needed seqeuntial pacing in the immediate post-operative period. Nine out of ten survivors were back to their preoperative rhythms on hospital discharge (6 sinus rhythm; 3 atrial fibrillation). One patient with preoperative trifascicular block who underwent reoperation to fix a paravalvular mitral leak needed a permanent pacemaker (VVI). The follow-up ranged from 1 month to 64 months (median 6 months) and is 100% complete. There was no late death or new arrhythmia. Conclusions Extended trans septal approach is safe. It gives excellent exposure of the mitral valve. division of the sinus node artery is not deleterious in the short to intermediate term. Presented at the 50th Annual Meeting of IACTS. New Delhi, Feb. 2004.