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Biomedical subjects

K Ray

Publications and source records attributed to K Ray.

At least 127 records · Page 7Linked to original sources
PubMed1996

An improved diagnostic test for rod cone dysplasia 1 (rcd1) using allele-specific polymerase chain reaction.

PURPOSE: To develop an improved diagnostic test for rod-cone dysplasia type 1 (rcd1). The rcd1 phenotype is an early onset, autosomal recessive disease caused by a mutation in the canine rod cyclic GMP phosphodiesterase beta-subunit (PDE6B) gene. A G to A transition in codon 807 at nucleotide position 2420 results in a stop codon. This is the only disease causing mutation detected so far in the canine PDE6B gene. METHODS: Allele specific primers were designed in which the 3 end had the nucleotide corresponding to either the wild type or the mutant rcd1 allele. PCR was done using the allele specific primers in combination with a common primer complementary to the opposite strand to distinguish between the wild type and the rcd1 alleles. RESULTS: The wild type and rcd1 alleles were identified successfully in two independent ASPCRs done with two different sets of allele specific primers. Further, both alleles could be amplified in a single tube and distinguished based on the size difference of the PCR products using one allele specific primer of altered length by the addition of a 9 nucleotide long linker. CONCLUSIONS: We have developed an improved diagnostic test for the disease based on ASPCR such that the presence or absence of different size amplified fragments provides direct determination of the genotype. In contrast to previously reported diagnostic tests, this method is more efficient because it eliminates the need for any further manipulation of the PCR product.

3',5'-Cyclic-GMP Phosphodiesterases↗
PubMed1996

Supplier-managed inventory: schedule sharing.

Supplier-managed inventory (SMI) is a methodology that provides a true win-win partnership between customers and suppliers. SMI supports flexibility for the customer to change schedules and flexibility to the supplier to decide when and how much to ship. All this is accomplished via electronic data interchange (EDI), which communicates the customer's gross requirements, inventory, and desired minimum/maximum inventory levels.

Consumer Behavior↗
PubMed1996

Nonallelism of erd and prcd and exclusion of the canine RDS/peripherin gene as a candidate for both retinal degeneration loci.

PURPOSE: To determine whether early retinal degeneration (erd) and progressive rod cone degeneration (prcd), two canine hereditary retinal degenerations, are caused by allelic mutations; to determine the cDNA sequence of the canine RDS/peripherin homolog (CFRDSP); and to test whether mutations(s) in CFRDSP cause(s) either erd or prcd. METHODS: Three erd-affected dogs were crossbred to three prcd-affected dogs, and their progeny were tested by electroretinography and retinal morphology for evidence of retinal degeneration. Canine RDS/peripherin cDNA was cloned and sequenced after reverse-transcription-polymerase chain reaction (RT-PCR) of total retinal RNA. A set of overlapping fragments of CFRDSP cDNA amplified from normal and prcd-affected retinal RNA was examined by double-stranded conformational polymorphism analysis for evidence of any mutation in prcd-affected dogs. RDS/peripherin-specific restriction fragment length polymorphism (RFLP) allelic differences within informative prcd and erd pedigrees were sought by digestion of amplified regions of the CFRDSP gene with different restriction enzymes. A Hinf I RFLP was identified with alleles segregating in a set of prcd and erd informative pedigrees. Linkage of CFRDSP to either prcd or erd was tested using the LINKAGE analysis package. RESULTS: All progeny from the erd x prcd cross were phenotypically normal at ages beyond the age of diagnosis for both parental disorders. The sequence of CFRDSP cDNA is reported (Genbank accession U27349). It is, overall, 79% identical at the nucleotide level with the corresponding human sequence. The coding region shares 89% and 93% nucleotide identity with the corresponding human and feline sequences, respectively. No mutation has been identified in the coding region of CFRDSP in prcd-affected dogs. In prcd pedigrees informative for both prcd and the CFRDSP Hinf I RFLP, a minimum of six obligate recombinants were identified. Similarly, in erd pedigrees, 14 of 29 progeny informative for both erd and this RFLP were obligate recombinants. CONCLUSIONS: The canine erd and prcd mutations are nonallelic. The canine RDS/peripherin gene (CFRDSP) has been excluded as a candidate for both prcd and erd. The demonstrated informativeness of the canine pedigrees on which these studies were based will enable testing other candidate genes for prcd and erd. Sequence information of CFRDSP will enable testing this locus as a candidate in other canine hereditary retinal degenerations.

Alleles↗
PubMed1995

Isolation of cDNA clones encoding eight different human G protein gamma subunits, including three novel forms designated the gamma 4, gamma 10, and gamma 11 subunits.

With the growing awareness that the G protein beta and gamma subunits directly regulate the activities of various enzymes and ion channels, the importance of identifying and characterizing these subunits is underscored. In this paper, we report the isolation of cDNA clones encoding eight different human gamma subunits, including three novel forms designated gamma 4, gamma 10, and gamma 11. The predicted protein sequence of gamma 4 shares the most identity (60-77%) with gamma 2, gamma 3, and gamma 7 and the least identity (38%) with gamma 1. The gamma 4 is modified by a geranylgeranyl group and is capable of interacting with both beta 1 and beta 2 but not with beta 3. The predicted protein sequence of gamma 10 shows only modest to low identity (35-53%) with the other known gamma subunits, with most of the differences concentrated in the N-terminal region, suggesting gamma 10 may interact with a unique subclass of alpha. The gamma 10 is modified by a geranylgeranyl group and is capable of interacting with beta 1 and beta 2 but not with beta 3. Finally, the predicted protein sequence of gamma 11 shows the most identity to gamma 1 (76% identity) and the least identity to the other known gamma (33-44%). Unlike most of the other known gamma subunits, gamma 11 is modified by a farnesyl group and is not capable of interacting with beta 2. The close resemblance of gamma 11 to gamma 1 raises intriguing questions regarding its function since the mRNA for gamma 11 is abundantly expressed in all tissues tested except for brain, whereas the mRNA for gamma 1 is expressed only in the retina where the protein functions in phototransduction.

Amino Acid Sequence↗
PubMed1995

malvolio, the Drosophila homologue of mouse NRAMP-1 (Bcg), is expressed in macrophages and in the nervous system and is required for normal taste behaviour.

We report the sequence, expression pattern and mutant phenotype of malvolio (mvl), the Drosophila homologue of mammalian natural resistance-associated macrophage proteins (NRAMPs). In the mouse, this novel transporter is encoded by Bcg, a dominant gene that confers natural resistance to intracellular parasites. mvl was identified in a screen for mutants that affect taste behaviour. We show that loss-of-function as well as insertional mutants in mvl display defects in taste behaviour with no alterations in the physiology of the sensory neurons. Activity of the reporter enzyme beta-galactosidase, that reflects the expression pattern of mvl, is seen in mature sensory neurons and in macrophages. The conceptual translation of the mvl cDNA shows a striking similarity (65% identity) with human NRAMP with almost complete identity in a conserved consensus motif found in a number of ATP-coupled transporters. Based on its phenotype and expression pattern as well as its structural similarities to NRAMPs and a nitrate transporter in Aspergillus nidulans, we discuss a possible role for MVL in nitrite/nitrate transport and its implications.

Amino Acid Sequence↗
PubMed1995

Cellular events during development of the olfactory sense organs in Drosophila melanogaster.

The olfactory sensilla on the antenna of adult Drosophila melanogaster develop during the first 36 hr after pupariation, from their anlagen in the cephalic disc. We have used tissue-specific beta-galactosidase expression in the enhancer trap strain A101.IF3 and the monoclonal antibody 22C10 as sensory cell markers, as well as the lineage tracer 5-bromo-2'-deoxyuridine (BrdU), to describe this process. The development of an olfactory sensillum begins with the selection of a "founder cell" (FC). These cells are distinct in that they possess large apically located nuclei revealed by beta-galactosidase expression in A101.IF3. In the following 6 hr, a few cells neighboring the FC also start expressing beta-galactosidase and together comprise a group. Cells of this group, denoted a "presensillum-cluster" (PSC), undergo at least one round of replication and give rise to all of the cells of a sensillum. A subset of the cells within each PSC and, later, all the sensory neurons are recognized by MAb22C10. The antennae of the mutant lozenge3 (lz3) lack all basiconic and some trichoid sensilla. The mutation apparently affects early steps in sensillum development and many of the FCs fail to form. Those that are present, however, proceed to form mature olfactory sensilla. Therefore, we conclude that the selection of an FC is the first step in olfactory sense organ development. Our study reveals novel aspects of sensory development in Drosophila.

Animals↗
PubMed1995

Intralesional sustained-release chemotherapy with therapeutic implants for treatment of canine sun-induced squamous cell carcinoma.

Squamous cell carcinoma (SCC) is the most frequently reported malignant epithelial tumour in dogs. Canine sun-induced SCC represents a useful animal model to evaluate new therapeutic modalities for possible human applications. We evaluated the safety and efficacy of treating sun-induced SCC in dogs with intralesional sustained-released chemotherapeutic gel implants that contained collagen, epinephrine (epi), and either 5-fluorouracil (5-FU) or cisplatin (CDDP). Dogs with large, single SCC or fields of multiple SCC were treated with 5-FU/epi gel for a minimum of three weekly injections. Dogs without a complete response were then treated with CDDP/epi gel for a minimum of three weekly treatments. We treated from one to 11 primary, recurrent, or refractory SCC per dog (tumour size 0.2-92.4 cm2; mean cumulative tumour area of 40.7 cm2 per dog). All dogs had at least 50% reduction in cumulative tumour area after treatment with 5-FU/epi gel. More than half (seven of 13) had complete resolution of SCC after treatment with 5-FU/epi gel or CDDP/epi gel. Minimal local tissue reactions were noted; no systemic toxicity occurred. Sustained-release chemotherapy using intralesional 5-FU/epi gel and CDDP/epi gel therapeutic implants is effective in treating canine sun-induced SCC of the skin.

Animals↗
PubMed1995

Molecular diagnostic tests for ascertainment of genotype at the rod cone dysplasia 1 (rcd1) locus in Irish setters.

Rod-cone dysplasia type 1 (rcd1) is one of several canine photoreceptor degenerations, collectively termed progressive retinal atrophy (PRA), that afflict different breeds of dogs. The rcd1 phenotype is an early onset autosomal recessive disease caused by a nonsense amber mutation, at codon 807, in the canine gene for the beta-subunit of rod cyclic GMP phosphodiesterase (canine PDEB). The mutation involves a G to A transition at nucleotide position 2420, which presumably would cause premature termination of the canine PDEB protein by 49 amino acid residues. In both a small pedigree study of Irish setters from the United Kingdom and in larger canine pedigree studies in the United States, this gene defect has been found to be the only mutation causing rcd1. Here we report development of a diagnostic test which unequivocally distinguishes the three genotypes at the rcd1 locus: rcd1/rcd1 (homozygous mutant, affected); rcd1/+ (heterozygous, carrier); and +/+ (homozygous normal, wildtype).

3',5'-Cyclic-GMP Phosphodiesterases↗
PubMed1995

IL-4 enhances IL-3 and IL-8 gene expression in a human leukemic mast cell line.

We examined the capacity of interleukin (IL)-4 to induce or enhance the expression of certain cytokines in resting and activated cells of the HMC-1 human leukemic mast cell line. The HMC-1 mast cells were cultured with or without recombinant human IL-4 and then activated with the calcium ionophore ionomycin. Stimulation of non-IL-4-treated cells with ionomycin (10 microM) for periods of 30 min to 8 hr induced expression of mRNA encoding IL-3, IL-4 and IL-8 but was without effect on levels of mRNA for tumour necrosis factor (TNF)-alpha or beta-actin. Culture of the cells with IL-4 (100 ng/ml) for 24 hr led to a small increase in resting levels of mRNA for IL-3 and IL-8 but not for IL-4, TNF-alpha or beta-actin. More notably, the IL-4 treatment produced a pronounced elevation of mRNA for IL-3 and IL-8 when the cells were subsequently activated with ionomycin. The IL-4 treatment produced a negligible effect on IL-4 mRNA, and no effect on TNF-alpha or beta-actin mRNA levels in ionomycin-activated cells. Quantitation of cDNA by competitive polymerase chain reaction (PCR) revealed that the IL-4 treatment produced a sixfold increase in ionomycin-induced levels of cellular IL-3 mRNA, a fourfold increase in induced IL-8 mRNA and less than a twofold increase in induced IL-4 mRNA. The IL-4 treatment led to a 15- to 20-fold increase in ionomycin-induced secretion of IL-3 product and a doubling of induced IL-8 product. These effects of IL-4 were not associated with increased mast cell numbers. We conclude that IL-4 alone is a weak activator of IL-3 and IL-8 gene expression in mast cells, but is able to enhance activation signals in stimulated mast cells leading to transcription and secretion of these two cytokines.

Base Sequence↗
PubMed1994

Cloning and sequencing of a rat heart cDNA encoding a G-protein beta subunit related to the human retinal beta 3 subunit.

A cDNA (pJ5) encoding a protein with significant sequence identity to the previously known beta 1, beta 2, beta 3 and beta 4 subunits of guanine-nucleotide-binding proteins (G proteins) has been cloned from a 8-12-week-old rat heart cDNA library. Its predicted amino acid (aa) sequence of 340 aa most closely resembles that of the human beta 3 subunit, showing 96% identity. Northern blot analysis revealed that the major mRNA corresponding to the rat pJ5 cDNA is 2.0 kb in length. It is expressed at a high level in the heart and at a much lower level in the brain.

Amino Acid Sequence↗
PubMed1994

Organization and expression of the Drosophila melanogaster D-G gamma 1 gene encoding the G-protein gamma subunit.

The organization and expression of the Drosophila melanogaster G-protein gamma subunit-encoding gene (D-G gamma 1) were analyzed. The results showed that the three D-G gamma 1 RNAs (1.1, 1.3 and 2.6 kb) are differentially expressed in different tissues. While the 2.6-kb RNA is found only in the neural tissues of late embryo, larva and adult, the 1.3-kb RNA is expressed only in the adult ovary. The 1.1-kb RNA, on the other hand, is predominantly expressed during embryogenesis and in the neural tissues of late embryo, larva and adult. Moderate expression of this RNA is also found in the imaginal discs and other larval tissues. Nucleotide (nt) sequence analysis showed that the 70-amino-acid polypeptide encoded by the 1.3-kb transcript of D-G gamma 1 is the same as that encoded by the 1.1- and 2.6-kb D-G gamma 1 transcripts reported earlier [Ray and Ganguly, J. Biol. Chem. 267 (1992) 6086-6092]. Both the 1.3- and 1.1-kb RNAs utilize the same polyadenylation site, but their 3'-UTR are 1662 nt shorter than that of the 2.6-kb RNA. Although transcription of all three RNAs starts at the same transcription start point (tsp), the 5'-UTR of the 1.3-kb RNA is 190-nt longer than that of the other two RNAs, due to the utilization of an 3' alternative splice site.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

Receptor mediated endocytosis and intracellular fate of interleukin 1.

We have studied the receptor mediated endocytosis of interleukin 1 (IL1) by the murine thymoma cell line EL4. These cells express the Type I IL1 receptor which binds its ligand with both high (Kd = 65 pM) and low affinity (Kd = 14.5 nM). We have shown that the two affinity states of the receptor have different rates of turnover both in the absence and presence of ligand. The biological responses of cells to IL1 stimulation are rapid and occur at low levels of receptor occupancy, whereas receptor mediated endocytosis of IL1 is relatively slow. Internalized IL1 appears to accumulate within cells in a non-degraded form and a proportion of this is associated with a detergent insoluble intracellular fraction, which may reflect transport to the nucleus. In this article, we review our previous findings and discuss the possible biological significance of IL1 internalization and nuclear targeting.

Animals↗
PubMed1994

Look-back investigation after human immunodeficiency virus seroconversion in a pediatric dentist.

Routine military screening identified human immunodeficiency virus (HIV) infection in an asymptomatic dentist who had three prior negative antibody tests. A look-back investigation evaluated the provider and the practice and provided notification, counseling, and HIV testing for patients. Test results were linked to dental procedures categorized by levels of invasiveness. Of 1631 patients tested, all were negative for antibody to HIV. Analysis of 12,164 procedures on 876 patients determined 20.5% of patients had procedures from the highest stratum of invasiveness; 42% had only low-risk exposure. Stratification of the degree of invasive exposure and clinical evaluation of disease stage in the infected health care worker are important in look-back investigations. The early stage of disease in the provider, the adherence to infection control precautions, and the low percentage of invasive procedures may have contributed to the lack of transmission. These results are consistent with current assessment that risk of transmission of HIV during invasive medical procedures is low.

Adult↗