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Biomedical subjects

R Ray

Publications and source records attributed to R Ray.

At least 91 records · Page 5Linked to original sources
PubMed1993

Quantitative analysis of mast cells in testicular aspiration cytology smears in azoospermic males.

Quantitative estimation of mast cells was done in testicular aspiration cytology smears of 90 azoospermic males. Cases included normal spermatogenesis (32), Sertoli cell only (38), late maturation arrest (16), and early maturation arrest (4). The pooled number of mast cells in 20 standard fields in Sertoli cell only and late maturation arrest cases were significantly higher than that of normal spermatogenesis (P < .001 and P < .01 respectively). Aggregates of mast cells were found around the seminiferous tubules in Sertoli cell only cases. The findings suggest that increased number of mast cells may be the cause or effect of testicular damage in idiopathic male infertility.

Biopsy, Needle↗
PubMed1993

Microencapsulated human parainfluenza virus induces a protective immune response.

Human parainfluenza type 3 (PI3) virus was incorporated into microspheres composed of a biocompatible and biodegradable DL-lactide and glycolide copolymer. Sera from mice immunized with these microspheres showed an antibody response to the viral glycoproteins and neutralized virus infectivity. The microspheres were also evaluated by intraperitoneal, oral, or intranasal administration to determine their protective efficacy in the hamster. After challenge infection of the intraperitoneally immunized hamsters with live PI3 virus, a significant reduction of virus titers in the respiratory tract was observed, demonstrating the protective efficacy of the microencapsulated viral antigens.

Administration, Intranasal↗
PubMed1993

Comparison of fine needle sampling by capillary action and fine needle aspiration.

Fine needle aspiration (FNA) and non-suction fine needle sampling (FNS) were performed consecutively in 107 lesions from 100 patients. The quality of diagnostic material was assessed using a scoring system based on the cellularity and amount of blood in the smear. The total score in the FNS group was significantly higher (P < 0.05) than that of FNA technique. The FNS procedure is less traumatic and equally cost effective and can be safely undertaken in liver, orbital and thyroid lesions. In lymph nodes, especially in children, FNS gives an excellent cellular yield. However, this procedure can not be advocated in cystic, bony and fibrous lesions.

Biopsy, Needle↗
PubMed1992

Triplex formation prevents Sp1 binding to the dihydrofolate reductase promoter.

The human dihydrofolate reductase (DHFR) promoter sequence contains two consensus binding sites for the Sp1 regulatory protein. We have determined the effect of intermolecular triplex DNA formation on Sp1 binding to the DHFR promoter. The DHFR Sp1 binding site I (-39 to -48 relative to the DHFR transcription start site) demonstrates concentration-dependent triplex formation with a 19-base pair G-rich oligonucleotide (GR19) which is complementary to the polypyrimidine strand. DNase I footprint analysis demonstrates that GR19 forms a DNA triplex structure with the DHFR promoter fragment in a sequence-specific manner. DNase I footprinting analysis also indicates that the orientation of binding of these G-rich oligonucleotides is antiparallel. CR19, a C-rich complementary oligonucleotide, on the other hand, does not form triplex. The DNase I protection pattern of DHFR promoter fragment incubated with both recombinant Sp1 and triplex-forming oligonucleotide suggests that triplex formation prevents Sp1 binding. This is confirmed by gel shift analysis which demonstrates that triplex formation by the Sp1 binding sequences of the DHFR promoter prevents recombinant Sp1 binding in a concentration-dependent manner. These results demonstrate that intermolecular triplex formation prevents regulatory protein binding in a sequence-specific manner.

Base Sequence↗
PubMed1992

Synthesis and anticholinesterase activity of new bispyridinium compounds.

Synthesis of new bis(1-methylpyridinium) compounds containing a 1,4-diacetylbenzene linkage between the pyridinium moieties from commercially available 2-, 3-, and 4-picoline precursors was accomplished via metallation, reaction of the picolyllithium with 1,4-dicyanobenzene, and subsequent quaternization of the resulting bispyridyl compounds. Acetylcholinesterase inhibitory activity was determined colorimetrically with purified electric eel enzyme. Examination of structure-activity relationships indicated that the 3-substituted pyridinium compound is the most potent isomer, followed by the 2-substituted isomer, and that the 4-substituted analogue is the least active.

Animals↗
PubMed1992

Indian hepatitis E virus shows a major deletion in the small open reading frame.

Enterically transmitted non-A, non-B hepatitis virus (HEV), the causative agent for sporadic and large epidemic outbreaks in developing countries, contains a positive-sense single-stranded RNA genome. The genome of the virus encodes three open reading frames (ORF1, ORF2, and ORF3). The gene segment corresponding to the small open reading frame (ORF3), overlapping between ORF1 and ORF2, was synthesized by reverse transcription-polymerase chain reaction (RT-PCR) from a number of previously identified HEV-positive clinical specimens. A DNA fragment of 166 bp was consistently obtained from all the clinical specimens. This small fragment was cloned, sequenced, and found to contain an open reading frame encoding only 41 amino acid residues. Comparison of our results with that of geographically related Burma HEV suggests a major inframe deletion of 246 bp in the ORF3 of Indian strain. The protein encoded by ORF3 does not appear to be useful for early serodiagnosis as a synthetic peptide deduced from the truncated ORF3 failed to show any demonstrable immunoreactivity against HEV-infected acute phase sera in an enzyme-linked immunosorbent assay.

Antibody Formation↗
PubMed1992

Distinct hemagglutinin and neuraminidase epitopes involved in antigenic variation of recent human parainfluenza virus type 2 isolates.

A panel of fourteen neutralizing anti-HN monoclonal antibodies (mAbs) to the prototype Greer strain of human parainfluenza virus type 2 (PI2) was used to determine the extent of antigenic variation in recent virus isolates. Competitive binding analysis with the mAbs indicated the presence of at least five distinct antigenic sites (I to V) on the HN glycoprotein molecule. MAbs recognizing different antigenic sites were found to be associated with the hemagglutinin (sites I, IV and V), hemagglutinin and neuraminidase (site II), or neuraminidase (site III) activities. The location of two distinct epitopes identifying the neuraminidase sites (II and III) was further verified from the generation of escape mutants. Antibodies directed to sites I and III failed to show any detectable binding or neutralizing activity against a number of natural PI2 virus isolates collected in Texas between 1986 and 1987. Interestingly, these natural variants, unlike the prototype virus, did not show any detectable neuraminidase activity with fetuin as a substrate and the enzyme activity was only detected with N-acetylneuramin-lactose as an alternative substrate. Despite the observed variation in the antigenic sites, primary infection with the prototype virus or the natural variants generated a protective immune response against challenge infection with the other virus strains.

Animals↗
PubMed1992

Tibial autogenous cancellous bone as an alternative donor site in maxillofacial surgery: a preliminary report.

This preliminary report reviews the use of the proximal tibial metaphysis as an alternative to other bone graft donor sites. A series of 21 cancellous grafts were procured from 20 patients using a predictable orthopedic approach. A singular finding was the overall lack of morbidity at the donor site and the apparent favorable quality and quantity of the procured bone. Data describing the use of tibial cancellous bone grafting in a wide range of maxillofacial reconstructive procedures are presented.

Adolescent↗
PubMed1992

Unidimensionality of alcohol dependence syndrome?

To evaluate the coherence of Alcohol Dependence Syndrome (ADS), as per DSM-III-R criteria, 72 and 223 subjects with alcohol dependence disorder from Hospital and Community settings, respectively, were interviewed. Nine DSM-III-R criteria assessing the dependence syndrome were factor-analysed. A single factor model provides an adequate description of the interrelationship among the nine criteria and supports the coherence of the dependence syndrome for the hospital sample but not for the community. A two factor model, namely 'withdrawal' and 'social', fits the community data. When the criteria were combined into cumulative scales, they formed good approximations of unidimensional Guttman scales for both the hospital and community settings. For hospital data, preoccupation was the highly central criterion (lambda = 0.95) in defining the dependence syndrome while 'can't stop' (v = 0.11) measured the most severe level of dependence. In the community the 'socially dysfunctional use' identified as a separate secondary factor measured the most severe level of dependence.

Adolescent↗
PubMed1992

Functional interactions between the fusion protein and hemagglutinin-neuraminidase of human parainfluenza viruses.

The fusion glycoprotein (F) and hemagglutinin-neuraminidase (HN) genes of human parainfluenza virus type 2 (PI2) were molecularly cloned and expressed in HeLa-T4 cells by using the vaccinia virus-T7 transient expression system. Expression of the F and HN proteins was detected by using immunoprecipitation and surface immunofluorescence staining. Although the F protein was found to be cleaved into F1 and F2 and expressed on cell surfaces, no cell fusion was observed. However, cotransfection of the F-protein gene together with the P12 HN gene resulted in significant levels of cell fusion. Cell fusion was also observed when separate cell cultures were transfected with the HN and F genes and the F-expressing cells were mixed with the HN-expressing cells. Surprisingly, when the PI2 F protein was expressed together with the parainfluenza virus type 3 (PI3) HN protein, no fusion was detectable in the transfected cells. Similarly, no fusion was found upon coexpression of the PI2 HN and PI3 F proteins. However, coexpression of the PI3 F and HN proteins resulted in extensive cell fusion, which resembled the PI2 coexpression result. These results indicate that under the conditions used, the F protein is unable to cause fusion by itself and the HN protein provides a specific function in cell fusion which cannot be provided by another paramyxovirus attachment protein. Further, the results suggest that a type-specific functional interaction between the F and HN proteins is involved in mediating cell fusion.

Animals↗