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Biomedical subjects

T Vijayakumar

Publications and source records attributed to T Vijayakumar.

At least 19 recordsLinked to original sources
PubMed2003

Impact of alphacypermethrin treated bed nets on malaria in villages of Malkangiri district, Orissa, India.

The impact of use of bed-nets treated with alphacypermethrin, at 20 mg (ai)/m2, in comparison to untreated nets or no nets on malaria vectors and malaria incidence was studied in tribal villages of Malkangiri district, Orissa state, India, which are highly endemic for falciparum malaria. Treated or untreated nets were supplied to the villagers in June 1999 and the nets were re-treated in September 1999, just before the rise in vector abundance and malaria incidence. The seasonal pattern of indoor resting Anopheles fluviatilis females was similar in all the three groups of villages before the start of intervention and the indoor resting catches were not significantly different between treatment-groups (two-way ANOVA, F = 1.53; d.f. = (2, 78); P = 0.2). During intervention, the indoor resting catches differed significantly among treatment groups (two-way ANOVA, F = 38.9; d.f.= (2, 66); P < 0.005). There was a 99% reduction in the indoor resting catches of An. fluviatilis in villages with treated nets and 61% reduction in villages with untreated nets compared with no-net villages. Comparison between villages with and without treated nets showed that there was 97% reduction in indoor resting catches in villages with treated nets. Pair-wise comparison showed that the reductions between villages with and without nets as well as between villages with treated and untreated nets were significant (Dunnett's C-test, P < 0.05). The indoor resting catches of Anopheles culicifacies did not differ significantly among the three groups of villages either before (F = 0.99; d.f. = (2, 121); P = 0.4) or during intervention (F = 0.21; d.f. = (2, 66); P = 0.8). Bioassay with 3 min exposure to treated bed nets showed 100% mortality of An. culicifacies for 2 months and with An. fluviatilis for 4.5 months after which tests were not carried out. In villages with treated nets, the Annual Parasite Incidence (API) significantly declined (P < 0.05) by about 65.7% and prevalence of infection among children (< 15 years) declined by 57.1%, whereas in villages with untreated nets, there was only 34% reduction in API and 13% in the prevalence of infection. In villages with treated nets, there was 48% reduction in API and 64% in prevalence of infection compared with villages with untreated nets. The impact of use of treated bed nets on other arthropod pests lasted for at least 1.5 months. After 1.5 months, observations on arthropod pests were not continued. The use rate of treated nets varied from 49.8 to 93.7% in three seasons and about 68.3% of treated bed nets and 60% of untreated nets were in good condition 1 year after distribution. Out of 489 users of treated net, five people complained of a burning sensation on the face (skin irritation) for 5 days following the distribution of treated nets. There were no other complaints of any discomfort in using the treated nets. The use of alphacypermethrin treated bed nets at 20 mg (ai)/m2 can be one of the options for reducing the vector abundance and incidence of malaria in this area.

Animals↗
PubMed2003

Correlation of age and birth order of parents with chromosomal anomalies in children.

One hundred children with suspected congenital and/or malformation and their parents who reported to SAT hospital, Medical College, Trivandrum, India formed the test group. Fifty children with no obvious anomalies or abnormalities and their parents formed the control group. The criteria for selection of the control was 1) the maternal age at delivery was below 30 years and 2) the parents belong to 1st or 2nd birth order. The chromosomal analysis was carried out in all the subjects using peripheral blood lymphocyte microculture to investigate for any constitutional chromosomal markers and quantitate the mutagen (bleomycin) sensitivity of the chromosomes. All the subjects were evaluated clinically and a complete family history was recorded. Chromosome anomalies were noted in 41 out of the one hundred children and in 4 out of the 200 parents of the test group. No constitutional aberrations were seen either in the parents or in the children of the control group. Bleomycin sensitivity study revealed a high b/c value in 35 children (24 hypersensitive and 11 sensitive) of the test group whereas in the control group the b/c values were low denoting hyposensitivity and very good DNA repair mechanism. This study reveals that the incidence of chromosome aberrations is higher when the age and birth order of parents are higher. A direct correlation was noted with parental order and b/c value. This was also true with the parental age and birth defects.

Abnormalities, Multiple↗
PubMed2001

rDNA-ITS2 polymerase chain reaction assay for the sibling species of Anopheles fluviatilis.

Species-specific differences in the nucleotide sequences of the second internal transcribed spacer (ITS2) region of the ribosomal DNA (rDNA) were used to develop a diagnostic polymerase chain reaction (PCR) assay for two of the sibling species of the Anopheles fluviatilis complex, members of which are major vectors of malaria in central and northern parts of India. This assay consisted of a three primer reaction, which could amplify the DNA of both the species producing fragments of two distinct sizes, 350 bp for species X and 450 bp for species Y, respectively. The assay was found to be highly specific and sensitive.

Animals↗
PubMed2000

Altered expression of jack fruit lectin specific glycoconjugates in benign and malignant human colorectum.

Lectins bind to terminal non reducing sugars of glycoconjugates in cell membranes and secretions. These glycoproteins can be very characteristic, both for the differentiation state of a tissue and for its grade of malignancy. The carbohydrate structures of cellular glycoconjugates in normal, adenoma, and carcinoma of human colorectum were analysed using HRP conjugated Jack Fruit Lectin (JFL). Fifty two rectal carcinomas, 18 adenomas and 25 normal rectal tissues were used for the study. Diaminobenzidine (DAB) was used as the visualant. Normal rectal tissues showed positive reaction with intense staining in more than 60% of the cells. Adenomas were seen to have moderate to intense staining with a range of 30 to 60% positive cells. The lowest levels of JFL staining were observed in invasive tumours. JFL binding was found to decrease with carcinomatous cells compared to adenomas and normal cells. A significant negative association was found between JFL binding and histologic abnormality (r = -0.85, P <0.0000). These results suggest that there are alterations in the carbohydrate structures of cellular glycoconjugates, which can be related to goblet cell differentiation, in normal, benign and malignant human colorectal tissue.

Adenocarcinoma↗
PubMed1998

Viruses in human oral cancers.

The role of viruses in the etiology of human oral cancer is critically reviewed. Available evidences show a positive correlation for human oral cancer with human papilloma virus (HPV), herpes simplex virus (HSV) and human herpes virus type-6 (HHV-6), having strongest association with HPV. These viruses may act alone or in combination with other carcinogens in the genesis of head and neck malignancies.

Adenoviridae Infections↗
PubMed1997

Correlation of lectin binding with lymph node metastasis in oral cancers.

Lymph node metastasis is an important factor that influences the treatment policy and prognosis of oral cancers. The cell membrane is known to play a role in the metastatic process. The aim of the present study was to evaluate the relationship of lectin binding frequency of oral cancer cells to their capacity to metastasize to the lymph node. Smears collected from tumours of 66 untreated patients were stained with Jackfruit lectin (JFL) conjugated with horseradish peroxidase (HRP), with diaminobenzidine dihydrochloride (DAB) as the visualant. The frequency of cells showing lectin binding was evaluated. The results showed that tumours with a high frequency of JFL binding cells had higher risk of lymph node metastasis (RR = 1.5). It was also found that a combined score integrating the percentage of lectin binding cells with known clinical parameters, like primary tumour size, local invasion and histological subgroup, had better utility than any of these individually in assessing risk of lymph node metastasis. The density of sugar residues on the cell surface may be of importance in determining the lymph node metastatic potential of oral cancers, and the present study suggests the need for further research in this area.

Adult↗
PubMed1996

Lectin histochemistry of oral premalignant and malignant lesions: correlation of JFL and PNA binding pattern with tumour progression.

The expression of glycoconjugates specific to Jack fruit lectin (JFL) and peanut agglutinin (PNA) in various clinicopathological stages of tumour progression in the oral mucosa were studied. These included various clinical forms of dysplastic and non-dysplastic oral leucoplakias, carcinomas, normal keratinising (gingiva) and non-keratinising (buccal mucosa) epithelia. It was seen that the binding patterns of PNA and JFL in the epithelial cells of various types of oral lesions were more or less similar. Normal non-keratinising epithelium showed mild membrane staining only in the spinal layers, while normal keratinising epithelium showed a moderate membrane staining and mild cytoplasmic staining in all layers. Moderate membrane and mild cytoplasmic staining were observed in leucoplakias, irrespective of various clinical or histological types. In carcinomas, the intensity of lectin binding was high, particularly in the membrane of differentiated cells. Correlation analysis of the binding pattern of PNA and JFL showed significant correlation in the membrane and cytoplasm of all layers with histological stages of tumour progression. The present study thus showed that PNA and JFL may be used as cytochemical probes in differentiating malignancy from benign lesions of the oral mucosa.

Carcinoma, Squamous Cell↗
PubMed1995

Evaluation of serum beta 2-microglobulin in premalignant and malignant lesions of the oral cavity.

Serum beta-2-microglobulin was estimated in patients with oral leukoplakia, oral submucous fibrosis, and oral cancer. The results were compared with that of an equal number of age- and sex-matched healthy controls. A definite increase in the level of beta 2-microglobulin was observed in patients with oral submucous fibrosis and oral cancer. Though the level of beta 2-microglobulin was found to be high in oral leukoplakia, it was not statistically significant. Further studies will validate the role of beta 2-microglobulin estimation to predict the malignant potential of oral submucous fibrosis.

Adult↗
PubMed1995

Mandibulofacial dysostosis. Case report.

A case of mandibulofacial dysostosis (Treacher Collins syndrome) is presented. Clinical features and skull radiographs revealed typical anomalies associated with the syndrome. Cleft of the soft palate and unerupted multiple supernumerary teeth were present in this case. No haematological, biochemical or immunological abnormalities could be detected in the patient. Pedigree analysis showed an autosomal dominant mode of transmission of the disease. Chromosomal studies did not reveal any structural or numerical discrepancies.

Adolescent↗
PubMed1994

Influence of plasma GSH level on acute radiation mucositis of the oral cavity.

PURPOSE: To see how pretreatment plasma GSH level influences the severity of acute radiation mucositis of the oral cavity during therapeutic irradiation in patients with oral cancer. METHODS AND MATERIALS: Thirteen patients with squamous cell carcinoma of the oral cavity form the subject material. Radical radiotherapy (60 Gy in 25 fractions over 5 weeks) was given using telecobalt. Pretreatment plasma GSH level was measured by Beutler's method. The normal tissue reaction during radiotherapy was monitored and graded. RESULTS: The GSH levels ranged from 10.6-90.5 microM/L (mean 30.6 microM/L). Those who had higher GSH levels developed less severe mucositis. The mean GSH levels in the groups with different severity of reactions were: Grade 2 (four patients) = 50.7 microM/L; Grade 3 (five patients) = 26.1 microM/L; Grade 4 (two patients) = 20.4 microM/L and Grade 5 (two patients) = 26.1 microM/L; Grade 4 (two patients) = 20.4 microM/L and Grade 5 (two patients) = 13.6 microM/L. CONCLUSION: Plasma GSH estimation has the potential to predict individual sensitivity to acute radiation mucositis and may particularly be useful in hyperfractionated regimes. The study also affirms the radioprotective role of GSH and suggests that this effect is either due to protection against membrane lipid peroxidation (since GSH does not enter the cell freely) or DNA damage (fractionated radiotherapy may permit freer entry of GSH into cell).

Acute Disease↗
PubMed1994

Jack fruit lectin-specific glycoconjugate expression during the progression of cervical intraepithelial neoplasia: a study on exfoliated cells.

The expression of glycoconjugates specific to Jack fruit lectin (JFL) was studied in the exfoliated squamous cells of different grades of intraepithelial and invasive neoplasia of the uterine cervix. It was observed that while normal cells showed almost negative binding, the lectin binding percentage of squamous cells significantly increased with increasing atypia of the epithelium. Correlation analysis between different groups revealed that mild lectin binding in cells had a negative correlation and intense binding had a positive correlation with various stages of tumor progression. These results indicate that the number of cells with aberrant expression of glycoconjugates increases as neoplastic transformation advances. The percentage of labeled and unlabeled cells also shows a continuous transition from low to severe grades of cervical intraepithelial neoplasia and invasive carcinomas. The present study therefore shows that JFL may be used as a probe for further elaboration of detection and grading of precancerous and cancerous lesions of the uterine cervix.

Female↗
PubMed1994

Oral squamous cell carcinoma in a case of dyskeratosis congenita.

Oral manifestations of dyskeratosis congenita (DCG) have received little attention in dental literature. This report is a case of dyskeratosis congenita in a 17-year-old female which was associated with oral lesions such as leukoplakia, superimposed candidal infection, desquamative gingivitis, and severe periodontitis. Histopathologic examination of the granular lesion on the right lateral border of the dorsum of the tongue showed well-differentiated squamous cell carcinoma. Etiopathogenesis, clinical features, and laboratory findings of this disease are discussed.

Adolescent↗
PubMed1994

Lectin cytochemistry in the exfoliative cytology of uterine cervix.

A lectin was isolated from the seeds of jack fruit (Artocarpus integrifolia) and purified using a column of immobilized N-acetyl-D-galactosamine. This jack fruit lectin (JFL) was then conjugated to horse-radish peroxidase (HRP) type VI and used to study the cell surface carbohydrate profile of the cytological smears of the uterine cervix using diaminobenzidine as substrate. Cervical smears from 15 healthy individuals and 65 patients with dysplasia, carcinoma in situ and carcinoma of uterine cervix were used for the study. Normal cells showed weak binding in the membrane as well as cytoplasm, whereas carcinomatous cells showed strong binding towards JFL. Carcinoma in situ cells showed a binding pattern similar to that of carcinoma. Dysplastic cells showed difference in binding in mild, moderate and severe dysplasia. The intensity of binding increased with the severity of the dysplasia. The nature and intensity of binding of jack fruit lectin with cancer tissues suggest that this lectin may be of use as a diagnostic aid in exfoliative cytology.

Carcinoma in Situ↗
PubMed1993

Immunomodulatory effects of a polysaccharide from Tamarindus indica.

A polysaccharide isolated and purified from Tamarindus indica shows immunomodulatory activities such as phagocytic enhancement, leukocyte migration inhibition and inhibition of cell proliferation. These properties suggest that this polysaccharide from T. indica may have some biological applications.

Adjuvants, Immunologic↗
PubMed1993

Fracture of tooth by internal resorption: case report.

A case of extensive internal resorption of the left mandibular first premolar in a 24 year old man is reported. The case presented with slight discolouration and mobility of the tooth. On radiological examination extensive internal resorption and a fracture line at the cemento enamel region was observed, separating the crown and root. The case was treated endodontically after surgical removal of the fractured fragment of the crown.

Adult↗
PubMed1993

Quantitation of circulating immune complexes in patients with chronic periapical lesions.

Quantitation of circulating immune complexes (CIC) was done in 45 patients with chronic periapical lesions. The levels were compared with those of age-matched healthy individuals. Both patients with chronic periapical granuloma and periapical cysts showed significantly higher levels of CIC than the controls. This observation indicates that the continuous presence of root canal antigens may cause elevated levels of circulating immune complexes. The possibility of chronic periapical lesions acting as foci of infection is discussed, and the importance of early treatment of these conditions is emphasized.

Adult↗