Cytomixis impairs meiosis and influences reproductive success in Chlorophytum comosum (Thunb) Jacq. - an additional strategy and possible implications.

Spontaneous intercellular chromatin migration/cytomixis was observed to occur in the pollen mother cells (PMCs) of the Chlorophytum comosum for the first time. The migration through cytomictic channels was more pronounced in meiosis-I and very rare in meiosis-II. The process was associated with erratic meiosis, which was characterized by defects in chromosome organization and segregation. Cytomixis was more intense in the month of April than in July and consequently the frequency of meiotic irregularities was much more pronounced during the month of April. As a consequence of abnormal meiosis, fertility was drastically reduced resulting in meager seed efficiency of 17% only. Recombination system also does not guarantee the release of sufficient variability. We view the phenomenon of cytomixis as genetically controlled mechanism involving meiotic genes and operating through signal transduction pathway triggered by the environmental stimuli. The evolutionary significance and tenable hypothesis in the backdrop of existing literature is also proposed.

Comparative evaluation of the clinical efficacy and safety of ondansetron and metoclopramide in the prophylaxis of emesis induced by cancer chemotherapy regimens including cisplatin.

The efficacy and safety of ondansetron was evaluated and compared with metoclopramide in 93 patients receiving cisplatin containing cancer chemotherapy in a randomized, parallel group study. 8 mg Ondansetron i.v. was administered prior to chemotherapy followed by two further doses of 8 mg i.v. over the first 24 hours. Ondansetron 8 mg b.d. was then administered orally for the next 5 days. The metoclopramide dosage was 20 mg i.v. prior to chemotherapy followed by 2 i.v. doses of 10 mg each, 4 hours apart. For the next 5 days, an oral dose of 20 mg metoclopramide was administered. The anti-emetic efficacy of ondansetron as a prophylactic treatment was found to be significantly more effective than metoclopramide both during the acute and delayed phase of nausea and vomiting. Both treatments were well tolerated with no reported side-effects.

Evaluating efficiency of bone marrow harvest and its manipulation--role of CD 34 positivity.

We evaluated harvested marrow cells for total nucleated cells (27.49 x 10(9)), absolute 'lymphocyte' count (6.29 x 10(9)) and CD 34 positive cells (3.57 x 10(9)). The same parameters were studied after in vitro manipulation to remove RBCs and plasma. Reinfused WBCs contained 12.87 x 10(9) nucleated cells, 4.25 x 10(9) absolute 'lymphocyutes' and 3.34 x 10(9) CD 34 positive cells. The corresponding figures for loss during in vitro manipulation (tubing, RBCs and plasma) are 14.62 (53.18%), 2.04 (32.43%) and 0.23 x 10(9) (6.44%) cells respectively. Therefore CD 34 positivity may be a better indicator of total yield, loss during manipulation and reinfusion of hemopoietic progenitor cells in bone marrow transplantation.