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Biomedical subjects

J Gupta

Publications and source records attributed to J Gupta.

At least 55 records · Page 3Linked to original sources
PubMed1990

Partial purification and characterization of trehalase from axenically grown myxamoebae of Dictyostelium discoideum.

Lysosomal trehalase from the myxamoebae of Dictyostelium discoideum has been partially purified. The behavior of the enzyme under different chromatographic and electrophoretic conditions reveals its close similarities to other lysosomal enzymes that have been studied earlier. The cellular trehalase, which is electrophoretically homogeneous, appears as two peaks of activity when subjected to hydroxyapatite and gel filtration chromatography. The enzyme has isoelectric points of 4.0 and less than 2.5. Among natural disaccharides tested, the purified trehalase showed absolute specificity for trehalose with an apparent Km of 1.15 mM. However, the enzyme efficiently utilized the synthetic sugar alpha-D-glucosyl fluoride as a substrate. Various methods were employed to estimate the apparent molecular weight, which was found to lie in the range of 30-162 kDa.

Chromatography↗
PubMed1989

Study of multiple human papillomavirus-related lesions of the lower female genital tract by in situ hybridization.

Twenty-six women with multiple human papillomavirus (HPV)-related lesions of the lower genital tract were investigated by immunohistochemistry for the internal genus-specific capsid antigen of HPV and by DNA-DNA in situ hybridization with 35S-radiolabeled probes for sequences of HPV-6/11, HPV-16, and HPV-18. The vulva was the most frequently affected site in all of these cases; the cervix was the second most frequently affected site. The lesions displayed the features of papillomavirus infection in 14 patients, and there was also histologic evidence of early neoplasia in 12 patients. The mean age of patients with and without neoplasia was 40 and 30 years, respectively. Evidence of HPV association was found in 73% of the vulvar lesions and in 40% of the other synchronous lesions by one or both methods. Viral DNA was found in 67% of patients with neoplasia and in 71% of patients without neoplasia. Eleven of 12 HPV-positive patients with neoplasia revealed the presence of HPV-16 in their tissues by in situ hybridization. On the other hand, 50% of those without neoplasia had HPV-16 DNA, whereas the presence of HPV-6/11 was found in the other 50%. The clinical course of the disease, the distribution of HPV type, and the type of antigen in patients with and without neoplasia suggest that progression to neoplasia was associated with HPV-16. These results stress the practical value of the in situ hybridization method for the identification of those patients with HPV infection who are at risk for progression to malignancy.

Antigens, Viral↗
PubMed1988

Modulation of octopamine-mediated production of cyclic AMP by phorbol-ester-sensitive protein kinase C in an insect cell line.

The presence of protein kinase C (EC 2.7.1.37) in an insect cell line has been demonstrated. Phorbol 12-myristate 13-acetate (PMA), in micromolar concentrations, activated protein kinase C with a translocation of the enzyme from the cytosol to the particulate fraction. Cyclic AMP production in the presence of PMA, octopamine and a combination of both increased in a dose-dependent and time-dependent fashion. The biologically inactive 4 alpha-phorbol 12,13-didecanoate had no effect on protein kinase C activity or on octopamine-mediated cyclic AMP production. Pretreatment of the cells with pertussis toxin had no effect on the response of cells to octopamine or PMA. However, pretreatment with cholera toxin resulted in increased cyclic AMP production which was further enhanced when both cholera toxin and PMA were used in combination. Our data indicate that the octopamine-mediated cyclic AMP production is modulated by protein kinase C.

Animals↗
PubMed1988

High prevalence of genital tract papillomavirus infection in female adolescents.

To investigate clinical condyloma, abnormal cervical cytologic findings, and evidence of human papillomavirus infections, 89 adolescent girls were examined. Cellular DNAs extracted from exfoliated cervical cells were examined for human papillomavirus genomic sequences by Southern transfer hybridization using 32P-labeled human papillomavirus DNA probes. Human papillomavirus sequences were detected in 12 (13%) young women, abnormal cytologic specimens in 21 (24%), and vulvar condylomas in 12 (13%). The human papillomavirus types identified included HPV-6/11 (four instances), which is known to be associated with benign lesions, and HPV-16, -18, and -31 (eight instances) which are considered to have oncogenic potential. Two young women were infected with both HPV-16 and -31. Human papillomavirus sequences were found in 48% of the young women with abnormal cytologic findings and in 3% of patients with normal cytologic findings (P less than .0001). Condylomatous changes in the cervical smear were associated with the presence of HPV-6/11 and mild dysplasia with the presence of HPV-16, -18, and -31. The presence of vulvar condylomas correlated with condylomatous changes in the cervical smear and with the recovery of HPV-6/11 from the cervical epithelium. The results indicate that the prevalence of human papillomavirus infections in this population is high and that a majority of the infections are with viruses associated with lower genital tract malignancies.

Adolescent↗
PubMed1987

Topographic study of cervical condyloma and intraepithelial neoplasia.

In this study of 101 cervical conization specimens, the location and the size of condyloma and intraepithelial neoplasia (dysplasia and carcinoma in situ) were mapped using the last endocervical gland as the marker for the original squamocolumnar junction. Condylomatous changes were identified in 85% of cervices affected by the intraepithelial neoplasia, and were in direct contact with 68% of intraepithelial neoplasms. The proximal location of intraepithelial neoplasia in relation to the condyloma can be explained by the occurrence of neoplasia just proximal to the condyloma and subsequent expansion of neoplasia towards the cervical canal. This study adds topographic evidence linking cervical condyloma to the development of intraepithelial neoplasia.

Carcinoma in Situ↗
PubMed1987

Human papillomavirus-associated early vulvar neoplasia investigated by in situ hybridization.

Of 21 consecutive cases of early vulvar neoplasia studied at the Istituto Nazionale Tumori of Milan, 62% appeared to be related to papillomavirus infection. This conclusion is the result of the present study by in situ hybridization with DNA probes of human papillomavirus (HPV) 6/11, 16, and 18 and of previous ultrastructural and immunohistochemical investigations. The proportion of cases associated with HPV was 78.5% for those (11/14) with histologic evidence of viral infection and 33% for those without (2/6). HPV 16 was detected in all cases that were positive by in situ hybridization except for one, which showed HPV 6/11 DNA. In one case there was a mixed triple infection for HPV 6/11, 16, and 18. The patient who was positive for HPV 6/11 had a giant condyloma associated with an inguinal lymph node containing a metastatic well-differentiated squamous cell carcinoma. Three cases were positive for papillomavirus internal capsid species-nonspecific antigen (PV-Ag) (with ultrastructural evidence of virions in one of them) and were negative for HPV-DNA hybridization. They appeared to be infected with a type of HPV not identified by the available probes. Three cases, and two sites of two other cases with double infection, were HPV-DNA-positive and PV-Ag-negative. They illustrate the limitation of immunohistochemical investigation in cases with high-grade intraepithelial neoplasia. Six cases of verrucous carcinoma of the vulva were negative for HPV DNA by in situ hybridization.

Carcinoma, Papillary↗
PubMed1987

Association of human papillomavirus type 16 with neoplastic lesions of the vulva and other genital sites by in situ hybridization.

The authors examined paraffin sections from 85 genital tract tissues from 49 cases for the presence of human papillomavirus (HPV) Types 6/11, 16, and 18 by stringent in situ hybridization using 35S-labeled viral DNA probes, and for viral capsid antigen by the immunoperoxidase test. The cases, selected mostly on the basis of vulvar pathology, were distributed as follows: early neoplasia (Group I, 6 cases); early neoplasia with viral cytopathic effect (CE) (Group II, 24 cases); and papillomavirus infection (PVI) (Group III, 19 cases). Available tissues from all affected sites were examined when the disease was multicentric. One or more viral DNAs were identified in 58% of 77 tissues from Groups II and III and in 2 of 8 tissues from Group I. HPV-6/11, HPV-16 and HPV-18 DNAs were detected, respectively, in 25, 24, and 2 tissues; 3 tissues were infected simultaneously with either two or three viruses. Viral DNA was identified at more than one site in 14 of 30 DNA-positive patients; in 10 of these, a single type was detected at all sites in the same patient. The viral DNA was localized mostly in areas showing viral cytopathology. The presence of HPV-16 correlated with neoplasia. HPV-16 DNA was identified in the 2 virus-positive tissues showing neoplasia, in 17 of 20 (85%) of the DNA-positive tissues showing neoplasia with CE, and in 5 of 25 (20%) of the DNA-positive tissues showing PVI. Conversely, HPV-6/11 was found in 25% of the DNA-positive tissues showing neoplasia with CE and in 80% of the cases of PVI. An HPV genome was identified in neoplastic cells in 14 instances; in all but 1 case, the genome was HPV-16. The association of HPV-16 with neoplasia was seen for both vulvar and cervical lesions. Viral antigen was detected in 83% of lesions associated with HPV 6/11 and in 62% of lesions associated with HPV-16.

Adult↗
PubMed1985

Identification of genital tract papillomaviruses HPV-6 and HPV-16 in warts of the oral cavity.

Warty lesions of the oral cavity were examined for etiologic association with genital tract papillomaviruses HPV-6, HPV-11, and HPV-16. DNAs extracted from ten oral biopsies were screened for HPV genomic sequences by Southern transfer hybridization with 32P-labeled viral DNA probes. Nonstringent hybridization with an HPV-6 probe revealed papillomavirus DNA sequences in four of seven tissues with histologic evidence of papillomatosis, in none of two tissues without histologic evidence of papillomatosis, and in one tissue that was not examined by histology. Stringent hybridization tests with HPV-6 and HPV-16 probes identified the genome in one tissue as being HPV-16, in a second tissue as being HPV-6 subtype a, and in a third tissue as HPV-6 (subtype unidentified); papillomavirus DNA sequences in two tissues are as yet not identified. An additional case of HPV-6 or HPV-11 related oral cavity lesion was diagnosed by in situ hybridization of paraffin sections with a 35S-labeled, mixed HPV-6 + HPV-11 probe. The hybridization in the positive section was extensive and confined to epithelial nuclei. The oral lesions associated with genital tract papillomaviruses were asymptomatic, multiple or single, and were located in different parts of the oral cavity, for example, on the gingivae, on the tongue, on the lip, on the tonsillar pillar, and on the floor of the mouth.

Adolescent↗
PubMed1985

Specific identification of human papillomavirus type in cervical smears and paraffin sections by in situ hybridization with radioactive probes: a preliminary communication.

Cervical Papanicolaou smears and paraffin sections of biopsy specimens obtained from women attending dysplasia clinics were examined for viral DNA sequences by in situ hybridization technique using 35S-labeled cloned recombinant DNA probes of human papillomavirus (HPV) types 6, 11, and 16. These and one unrelated DNA probe complementary to measles virus RNA were labeled by nick translation using either one or two 35S-labeled nucleotides. The radiolabeled probes were reduced in size with DNase to 60-160 nucleotides. Paraffin sections and cervical smears were collected on pretreated slides, hybridized with the probes under stringent or nonstringent conditions for 50 h, and autoradiographed. Additional cervical specimens from the same women were examined for the presence of genus-specific papillomavirus capsid antigen by the immunoperoxidase technique. Preliminary results may be summarized as follows. The infecting virus could be identified in smears as well as in sections. Viral DNA sequences were detected only when there were condylomatous cells in the specimen and in only a proportion of the condylomatous cells. Even under stringent conditions, some specimens reacted with both HPV-6 and HPV-11. None of the specimens hybridized with HPV-16 or with the unrelated probe. In some instances, the cells did not hybridize with any of the three probes even when duplicate specimens contained frankly condylomatous, capsid antigen-positive cells. In situ hybridization of Papanicolaou smears or of tissue sections is a practical method for diagnosis and follow-up of specific papillomavirus infection using routinely collected material.

Adult↗
PubMed1983

Toxicity studies of metabolites of some fungal isolates in albino mice.

Crude metabolites of 21 of 60 fungal cultures isolated from some of the common cereals collected from different parts of India were found to be toxic. Of these toxin-producing fungi, 79% caused hepatic pathology of varying severity in mice. Serum glutamate pyruvate transaminase values and blood urea nitrogen were found to be high in such experimental animals.

Alanine Transaminase↗
PubMed1981

Histopathology of Mycotoxicosis produced in Swiss albino mice by metabolites of some fungal isolates.

Of 199 fungal cultures isolated from some of the common cereals collected from different parts of Uttar Pradesh and Madhya Pradesh, 70 produced toxic metabolites. Of the 70 fungi isolated, 59 produced toxins which caused visible lesions in livers, kidneys, and spleens but did not cause mortality. Toxicity, graded in terms of the mortality rate and the extent of lesions in livers, kidneys, and spleens, was found to be highest in various species of Aspergillus (40%), followed by Chaetomium spp. (31%).

Animals↗
PubMed1977

Recovery of Paramyxovirus from the jejunum of patients with multiple sclerosis.

Paramyxovirus, presumably measles, has been recovered by cocultivation or cell-fusion techniques from jejunal biopsy specimens of 6 consecutive patients with multiple sclerosis. Virus has been identified by immunofluorescence of antigen in infected HEp-2 and BSC-1 cells, by electron microscopy, and by haemagglutination of rhesus-monkey erythrocytes.

Animals↗