Regeneration of plantlets in Sapindus trifoiatus L.

Continuous production of healthy plantlets of Sapindus trifoliatus L. was achieved via somatic embryos from long term cultures of an embryogenic mass (EM). A highly embryogenic culture of S. trifoliatus L. was obtained by recurrent embryogenesis from somatic embryos cultured on Murashige and Skoog's (MS) medium supplemented with kinetin (2.3 microM) and benzyladenine (8.8 microM). The cultures could be maintained without reduction of embryogenic competence for more than 20 months by subculture at 4 week intervals. About 90% mature somatic embryos on transfer to basal MS medium, germinated to plantlets, of which more than 70% survived when transferred to a sand and soil mixture in green house.

Loss of p53 gene as a biomarker of high risk oral leukoplakias.

We have investigated loss of heterozygosity of p53 tumor suppressor gene in Indian oral cancer patients, individuals with premalignant leukoplakia lesions, and corresponding normal mucosa, to study the status of p53 alleles in oral cancer pathogenesis. Fifty oral cancers, and 42 oral leukoplakia lesions and corresponding clinically normal oral mucosa from 18 individuals, were analysed. Peripheral blood cells (PBCs) from all the individuals and 47 normal healthy volunteers were also included in the study. Polymerase chain reaction(PCR) of p53 Exon4, followed by restriction enzyme digestion with AccII due to the enzyme polymorphic site at Exon4 codon72, was used to detect homozygosity/heterozygosity of p53 alleles, and compared with the allelic pattern in the corresponding PBC. The PCR product subjected to AccII digestion detected 259 bp, 160/99 bp fragments indicating heterozygosity of p53 alleles in 69% of the 139 individuals. On comparison of the p53 allelic distribution in the lesions or tumour tissues, and corresponding PBC, LOH was observed in 20.5% oral tumors and 22% leukoplakias. However, there was no evidence of LOH in the clinically normal mucosa available from 16 individuals with leukoplakia. Our studies demonstrated LOH of p53 allele in early and advanced stages of oral cancers, as well as leukoplakias, perhaps indicating p53 LOH as one of the early events in oral carcinogenesis. Thus, p53 LOH may be useful as a biomarker in defining a certain population of high risk leukoplakias that may progress to oral cancer.

Restriction fragment length polymorphisms of the human N-myc gene in normal healthy individuals and oral cancer patients in India.

Southern blot hybridization with N-myc oncogene probes coding for different regions of the N-myc gene demonstrated three polymorphic restriction sites in the Indian population. The SphI and PvuII polymorphic pattern due to the SphI polymorphic site in the second intron and the PvuII polymorphic site in the 3'-region of the human N-myc oncogene respectively, was similar to that reported in the Japanese population. The allelic frequency distribution for SphI polymorphism did not differ significantly for the S1 and S2 alleles representing presence (allele S1) or absence (allele S2) of a SphI site. However, the allelic frequency distribution was distorted in the case of PvuII polymorphism, as the frequency of P1 allele (0.7) indicating presence of PvuII site, was higher than the P2 allele (0.3) indicating absence of PvuII site, in the Indian population. An additional polymorphic HindIII site localised in the second intron of the N-myc gene was also observed in both the Indian oral cancer patients and the normal healthy individuals, indicating that this RFLP was not tumor associated and may perhaps represent N-myc alteration in the Indian population.

Recurrent ameloblastoma of the mandible and maxilla.

Sixteen cases of recurrent ameloblastomas of the mandible and maxilla seen over a 14 year period at the Tata Memorial Hospital were analysed with emphasis on recurrence patterns, type of primary surgery and surgical management. Seventy-five percent of the cases had conservative surgery at the first instance. In our experience, recurrent tumors could be excised widely even in unusual locations with good results.

Gastric transposition & deltopectoral flap for peristomal recurrence following total laryngectomy--a case report.

Stomal recurrence following laryngectomy presents a difficult problem with an incidence of 8.3-15%. Wide excision of the recurrence with mediastinal dissection, although the operation of choice,m is technically demanding and has a high morbidity and mortality. We recommend a technically easier procedure for reconstruction after palliative excision and present a case to illustrate it.

Primary tracheo oesophageal puncture our initial experience.

Our initial experience of 9 primary tracheo oesophageal punctures with Blom Singer prosthesis is reported. Patient selection was based on motivation, intelligence and socioeconomic status. Excellent speech resulted in 7 out of 9 patients (77%), with 2 failures (23%). There were no major complications. The results are encouraging, but a larger study is required to determine the role of this procedure in our conditions.

Composite resections for oral cancers--experience with 97 consecutive cases.

A retrospective study was carried out from the evaluable records of all (N = 97) patients who underwent composite resections in unit 'Head & Neck 'C' - Tata Memorial Hospital, over the years 1980, 81, 82, for a variety of oral cancers. The purpose of this study was to assess the true value of radical ablation. Tobacco addiction was observed in all patients with adequate documentation of habits. The vast majority of operations were performed for lesions of the buccal mucosa (N = 48) and lower alveolus (20); and squamous carcinoma was the predominant histologic type. Most patients presented with advanced T3 and T4 lesions. Nodal findings revealed a conspicuous disparity between clinical and pathological findings; and the final 'N' status was the most significant prognostic determinant. The results of reconstructive methods have also been reviewed. The majority of recurrences occurred within 12 months of surgery, local recurrence being commonest.

Solasodine levels in Solanum sisymbriifolium Lam.

Solasodine content in berries, leaves and stem of S. sisymbriifolium, using three different procedures, was 0.93, 0.73 and 0.23% respectively. Further in chromatogram not only solasodine but three more alkaloids (Rf 0.22, 0.48 and 0.88) were found which could not be identified due to lack of authentic samples.