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Biomedical subjects

K Goyal

Publications and source records attributed to K Goyal.

10 recordsLinked to original sources
PubMed2007

TRPM channel function in Caenorhabditis elegans.

The nematode Caenorhabditis elegans contains over 20 genes for TRP (transient receptor potential) channels which include members of all of the subclasses identified in mammalian cells. These proteins include three members of the TRPM (TRP melastatin) family: gon-2 (abnormal gonad development), gtl-1 (gon-2-like 1) and gtl-2. Although studies of these genes are at an early stage, we are beginning to understand their functions in the life of C. elegans. Mutations in gon-2 have defective gonad formation because of failures in the cell division of the somatic gonad precursor cells. gon-2 and gtl-1 are both expressed in the intestine of the animal. Experiments on gon-2,gtl-1 double mutants show that they have a severe growth defect that is ameliorated by the addition of high levels of Mg(2+) to the growth medium. gon-2,gtl-1 double mutants have defective magnesium homoeostasis and also have altered sensitivity to toxic levels of Ni(2+). Furthermore gon-2 mutants have reduced levels of I(ORCa) (outwardly rectifying calcium current) in the intestinal cells. Thus these two channels appear to play an important role in cation homoeostasis in C. elegans. In addition, perturbing the function of gon-2 and gtl-1 disrupts the ultradian defecation rhythm in C. elegans, suggesting that these channels play an important role in regulating this calcium-dependent rhythmic process. The tractability of C. elegans as an experimental animal and its amenability to techniques such as RNAi (RNA interference) and in vivo imaging make it an excellent system for an integrative analysis of TRPM function.

Animals↗
PubMed2005

Dehydration-induced tps gene transcripts from an anhydrobiotic nematode contain novel spliced leaders and encode atypical GT-20 family proteins.

Accumulation of the non-reducing disaccharide trehalose is associated with desiccation tolerance during anhydrobiosis in a number of invertebrates, but there is little information on trehalose biosynthetic genes in these organisms. We have identified two trehalose-6-phosphate synthase (tps) genes in the anhydrobiotic nematode Aphelenchus avenae and determined full length cDNA sequences for both; for comparison, full length tps cDNAs from the model nematode, Caenorhabditis elegans, have also been obtained. The A. avenae genes encode very similar proteins containing the catalytic domain characteristic of the GT-20 family of glycosyltransferases and are most similar to tps-2 of C. elegans; no evidence was found for a gene in A. avenae corresponding to Ce-tps-1. Analysis of A. avenae tps cDNAs revealed several features of interest, including alternative trans-splicing of spliced leader sequences in Aav-tps-1, and four different, novel SL1-related trans-spliced leaders, which were different to the canonical SL1 sequence found in all other nematodes studied. The latter observation suggests that A. avenae does not comply with the strict evolutionary conservation of SL1 sequences observed in other species. Unusual features were also noted in predicted nematode TPS proteins, which distinguish them from homologues in other higher eukaryotes (plants and insects) and in micro-organisms. Phylogenetic analysis confirmed their membership of the GT-20 glycosyltransferase family, but indicated an accelerated rate of molecular evolution. Furthermore, nematode TPS proteins possess N- and C-terminal domains, which are unrelated to those of other eukaryotes: nematode C-terminal domains, for example, do not contain trehalose-6-phosphate phosphatase-like sequences, as seen in plant and insect homologues. During onset of anhydrobiosis, both tps genes in A. avenae are upregulated, but exposure to cold or increased osmolarity also results in gene induction, although to a lesser extent. Trehalose seems likely therefore to play a role in a number of stress responses in nematodes.

Amino Acid Sequence↗
PubMed2002

Combined spinal epidural anaesthesia for vesico-vaginal fistula repair in an achondroplastic dwarf.

A 33-year-old achondroplastic female was scheduled to undergo vesico-vaginal fistula repair by the abdominoperineal route. Preoperative examination suggested a difficult airway so a combined spinal epidural technique was used. Subarachnoid block (sensory loss to T6) was established using 0.5% hyperbaric bupivacaine 1 ml. Anaesthesia was prolonged with incremental doses of epidural bupivacaine 0.5% (total 10 ml) and postoperative analgesia was provided with epidural morphine boluses.

Achondroplasia↗
PubMed2000

Thoracic radiculopathy caused by a myodil cyst.

We report the case of a myodil cyst causing a thoracic radiculopathy in a patient who had undergone a myelogram 30 years previously. Although myodil is no longer used, sequelae can continue to be seen for many years.

Contrast Media↗
PubMed1999

Treatment limiting decisions in a neurosurgical unit.

In a previous paper on mortality audit we reported on the use of treatment limiting decisions (TLDs) in a neurosurgical unit in the year 1988. In this paper we compare the findings of a similar audit for 1997. It appears that our unit's policy of openly discussing all TLDs in patients who die had led to such decisions being made at a more appropriate stage in the patient's illness. Regular review of TLDs is probably helpful in increasing the confidence of clinicians to make these difficult decisions openly and timeously.

Cause of Death↗
PubMed1987

Comparison of three serotests for the detection of pseudorabies antibodies in pigs.

The serum-neutralization test (SN), enzyme-linked immunosorbent assay (ELISA) and the radial immunodiffusion enzyme assay (RIDEA) were compared for the detection of pseudorabies (PRV) antibodies in swine sera. A total of 1285 serum samples were tested. All three tests were considered useful in determining the PRV antibody status of swine on a herd basis, but available evidence supports the continued use of SN as the definitive test because of possible false positive reactions associated with ELISA and RIDEA.

Animals↗