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Biomedical subjects

M K Nair

Publications and source records attributed to M K Nair.

At least 19 recordsLinked to original sources

Independent predictors of response and disease-free survival in oral cancer treated with radical radiation therapy.

There have been no reports concerning the independent predictors of response and disease-free survival (DFS) in oral cancer in India, where the highest incidence is reported. The authors analyzed the outcome of radical radiation therapy of 378 patients with oral cancer and found that the complete response rate within 6 months of completion of treatment was 45% and the 5-year DFS was 34% (95% confidence interval 29% to 39%). Regional lymph node involvement (P less than 0.001), histologic type (P less than 0.01), and the intraoral site of lesion (P less than 0.025) were identified as independent predictors of response when adjusted in a forward stepwise logistic regression analysis. The Cox proportional hazards regression analysis revealed that regional lymph node involvement (P less than 0.001) and histologic type (P less than 0.05) were independent prognostic factors for DFS. Patients with fixed regional lymph node involvement demonstrated a relative risk (RR) of 2.4 compared with those with N0 disease. Patients with well-differentiated squamous carcinoma had an RR of 2, and those with other histologic types (other than verrucous carcinoma) had an RR of 1.5.

Adult

Role of immune response in the prognosis of carcinoma of the uterine cervix: can in vitro analysis provide a better framework for more effective management?

Cancer of the uterine cervix is the single largest female malignancy in India and also remains a major problem facing oncologists in other parts of the world. While advances in radiation therapy and surgical techniques have made the treatment of cervical carcinoma impressive, limitations to successful management still remain. In fact, the 5-year survival rate, stage for stage, has not improved in the United States or world wide in the past 40 years. With an estimated half a million women developing this disease annually, this lack of improved survival poses an international unresolved health problem. Immune response has been shown to be a major factor involved in the course of the disease for this cancer. Immunologic monitoring was also shown to be of effective value in assessing the prognosis for cervical carcinoma. We studied the various immunologic abnormalities in cervical cancer, the effects of radiation therapy on immune function, prospects of an immunologic staging system, the relationship between human papillomavirus infection and the immune response, and the possibility of using in vitro immunologic assessment to provide a better framework for more effective management of cancer of the uterine cervix.

Antibody Formation

Cancer control programme in India: opportunities for implementation and evaluation.

Cancer is now being appreciated in India as an emerging public health problem. Approximately 600,000 new cancer cases occur in India every year, and the absolute number of new cancer patients will increase considerably, due to growth in the size of the population and an increase in the proportion of elderly persons due to improved life expectancy following control of communicable diseases. This emerging problem has received the attention of the Government of India, and some state governments within the Indian Federation have formulated National and State Cancer Control Programmes to deal with the situation. In the event of these programmes being implemented, consideration should be given now to measures of evaluation of the activities, as many of the indices, used to monitor programmes in developed countries, such as 15% reduction from peak cancer mortality, or in peak mortality from specific cancers, are not applicable in developing countries like India. Factors such as the pattern of tobacco habits in the community, knowledge, attitude and practice (KAP) patterns regarding cancer in the general population, referral practices, and the national pattern of extent of disease at presentation, gain considerable importance from the evaluation point of view. Our article mainly deals with the sources and the quality of baseline data for such factors and the realistic quantitative goals which could be set for the above factors.

Humans

Interferon and interleukin-2 induced spontaneous cell-mediated cytotoxicity: a preliminary evaluation.

The contribution of natural cell-mediated cytotoxicity and its modulation with biological response modifiers in antitumour immunity was evaluated in patients with precancers and cancers of the oral cavity. The results were compared to those in normal controls. Both groups of patients showed highly significant depression of the natural killer cell activity. This depression was stage-related, suggesting an influence of tumour or tumour products on this activity. Depression in augmentation of this cytotoxicity was evident in both patient groups with cancers and precancers, suggesting a defect in the response of killer cells to biological response modifiers for reasons other than the tumour per se.

Cells, Cultured

Comparison of oral squamous cell carcinoma in younger and older patients in India.

This study examines the demographic, aetiological and clinico-pathological features of 37 patients with oral squamous cell carcinoma (SCC) who were less than 35 years old and a comparable number of patients who were greater than 60 years old. The study was undertaken at the Regional Cancer Centre, Trivandrum, India, between 1988 and 1990. In patients younger than 35 years old, oral SCC occurred more commonly in females, was apparent in all social classes and was associated with fewer aetiological factors. The tumours manifested predominantly as invasive lesions affecting the tongue and there was early spread to lymph nodes. By contrast, in patients older than 60 years of age, oral SCC was more common in males, occurred more frequently in social classes III and IV and was always seen in association with smoking, alcohol or pan chewing. These latter tumours presented as exophytic lesions of the buccal mucosa or gingivae and spread late to lymph nodes. The results indicate that the biological behaviour of oral SCC in young patients may be distinct from that occurring in older patients.

Adult

Chromosomes in Hodgkin's disease--analysis of involved lymph nodes.

Chromosome studies carried out using lymph nodes of 47 patients with Hodgkin's disease gave analyzable metaphases in 22 patients of which 16 (72.7%) showed chromosome abnormalities. The modal chromosome number ranged from near-diploidy to near-tetraploidy. Chromosomes 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 18, 21 and 22 were involved in trisomy and tetrasomy whereas chromosome 17 was involved in monosomy. Structural abnormalities like deletions of chromosomes 1(p13), 6(q24) and addition of chromatin material to chromosomes 11(q13) and 14(q32) were also detected. The involvement of chromosomes 2, 5, 12, 18 and 21 in numerical abnormalities, and chromosome 14(14q+) in structural aberrations was found to be more frequent in Hodgkin's disease. No clinical correlation could be defined between the various chromosome abnormalities and prognosis of these patients.

Adolescent

Tissue binding pattern of plant lectins in benign and malignant lesions of thyroid.

N-acetyl D-galactosamine specific lectins were isolated from the seeds of Jack Fruit (Artocarpus integrifolia) and Winged bean (Psophocarpus tetragonolobus) and D-galactose specific lectin was isolated from peanut (Arachis hypogaea). These lectins were conjugated to Horse Radish Peroxidase (HRP) and were used to study the lectin binding properties of benign and malignant lesions of the thyroid. For comparison of the results 10 normal fresh autopsy specimens were included in the study. The Peanut lectin (PNL) and Jack fruit lectin (JFL) conjugates showed positive binding with the cells in different lesions, while Winged Bean Lectin (WBL), despite its having a common inhibitory sugar, showed no binding even after neuraminidase treatment. These lectins revealed difference in the composition of glycoconjugates of benign and malignant thyroid cells. The HRP conjugated JFL and PNL may be of use in distinguishing carcinomatous tissues from benign tissues which makes them potential tools in the differential diagnosis of thyroid lesions.

Diagnosis, Differential

Evaluation of salvage surgery in heavily irradiated cancer of the buccal mucosa.

This report describes the authors' experience with salvage surgery in 78 patients with carcinoma of the buccal mucosa who failed after high-dose radical radiation therapy at Regional Cancer Centre, Trivandrum, India. Forty-four patients (56%) required a hemimandibulectomy for adequate tumor clearance. Fifty-four patients (69%) required a primary reconstructive procedure for wound closure. Follow-up periods ranged from 28 months to 63 months (median follow-up, 41 months). Thirteen patients (17%) developed nonfatal postoperative complications. Thirty-one patients recurred after surgery, five of whom were again salvaged by further surgery. Overall, the recurrence rate was 36%. Most of the recurrences (26/31) were at the primary site. The overall 5-year actuarial disease-free survival after salvage surgery was 59.7%. T stage of the recurrent tumor and its skin infiltration emerged as factors which significantly influenced disease-free survival (P less than 0.05).

Adult

Lymphocyte subset distribution after radiation therapy for cancer of the uterine cervix. Possible prognostic implications and correlation with disease course.

An analysis of lymphocyte subpopulations was done in patients with cancer of the uterine cervix before and at different intervals after the commencement of radiation therapy. A common feature was a duration of T-cell and B-cell lymphopenia after therapy. The findings relating to the T-cell subsets were interesting. Although the CD4/CD8 ratio remained unchanged in Stages I/IIA for 24 months after treatment, patients with Stages IIB and III showed a lowering of the ratio immediately after treatment. Distinctive patterns of lymphocyte subset distribution were seen in a comparison between patients who were disease-free and those with recurrent disease. The CD4+ cell counts and CD4/CD8 ratio differed between the two groups, with consistent lowered values during the follow-up associated with recurrent disease. This study demonstrates the effects of radiation therapy in altering lymphocyte subset distribution, resulting in characteristic patterns which could be used as clinical and prognostic indicators.

Antibodies, Monoclonal

Periodontal space: a major route to bone involvement in oral cancer.

Oral cancers are presumed to involve mandible or maxilla by direct invasion and destruction of periosteum and underlying bone. In countries where there is a high incidence of oral cancers, most patients have poor dental hygiene and chronic periodontitis. We hypothesize that in such situations spread through the periodontal space is the major route to bone. We suggest that micro and macroscopic examination of the root surface can identify this and that this has to be done for proper 'T' grouping of tumours.

Bone Neoplasms

Remission of precancerous lesions in the oral cavity of tobacco chewers and maintenance of the protective effect of beta-carotene or vitamin A.

Participants in the intervention trials were fishermen (Kerala, India), who chewed tobacco-containing betel quids daily before and throughout the study period. Frequency of oral leukoplakia, micronuclei in oral mucosal cells, and alterations in nuclear textures were used as endpoints. Administration of vitamin A (60 mg/wk) for 6-mo resulted in complete remission of leukoplakias in 57% and a reduction of micronucleated cells in 96% of tobacco-chewers. beta-carotene (2.2 mmol/wk) induced remission of leukoplakia in 14.8% and reduction of micronucleated cells in 98%. Vitamin A completely suppressed and beta-carotene suppressed by 50% formation of new leukoplakia within the 6-mo trial period. After withdrawal of vitamin A or beta-carotene treatment, oral leukoplakias reappeared, frequency of micronuclei in oral mucosa increased, and nuclear textures reverted to those present before the administration of chemo-preventive agents. The protective effect of the original treatment could be maintained for at least 8 additional months by administration of lower doses of vitamin A or beta-carotene.

Areca

Sonographic evaluation of operability of malignant cervical lymph nodes.

Infiltration of the carotid artery by malignant cervical nodes is considered to be a contraindication for radical neck dissection in many centers. Clinical examination alone is unlikely to provide information on the fixity of nodes to the carotid artery. We studied the role of ultrasonography as an adjunct to clinical examination in screening patients for neck dissection. Twenty-seven patients with clinical neck node metastasis were chosen for ultrasonography. All of them had surgery and the findings were correlated. The findings revealed that this procedure is effective in delineating involvement of carotid artery by neck nodes and in identifying false-positive and false-negative cases. Since the sample of patients studied was small, the study is continuing in order to accrue a larger sample.

Adolescent

Growth faltering and developmental delay in children with PEM.

Anthropometric measurements, Somatic Quotient (SQ), Development Quotient (DQ), Motor Quotient (MoQ) and Mental Quotient (MeQ) in 136 children in the age group 1-24 months with varying degrees of protein energy malnutrition (PEM) were compared with an equal number of comparable well nourished children. There was a progressive reduction in SQ, DQ, MoQ and MeQ as the degree of PEM advanced. There was a direct linear correlation between SQ and DQ and between height and DQ in 4 degrees PEM. However, there was no direct correlation between head circumference and either DQ or MeQ.

Body Height

Trivandrum Developmental Screening Chart.

The Trivandrum Developmental Screening Chart (TDSC) was designed by selecting 17 test items from BSID (Baroda Norms). It was validated both at the hospital and community level against the standard DDST. TDSC had a sensitivity of 66.7% and specificity of 78.8%, which makes it an acceptable simple screening tool even for the community level worker.

Child, Preschool