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S S Gill

Publications and source records attributed to S S Gill.

At least 37 records · Page 2Linked to original sources
PubMed2000

The transporter-like protein inebriated mediates hyperosmotic stimuli through intracellular signaling.

We cloned the inebriated homologue MasIne from Manduca sexta and expressed it in Xenopus laevis oocytes. MasIne is homologous to neurotransmitter transporters but no transport was observed with a number of putative substrates. Oocytes expressing MasIne respond to hyperosmotic stimulation by releasing intracellular Ca(2+), as revealed by activation of the endogenous Ca(2+)-activated Cl(-) current. This Ca(2+) release requires the N-terminal 108 amino acid residues of MasIne and occurs via the inositol trisphosphate pathway. Fusion of the N terminus to the rat gamma-aminobutyric acid transporter (rGAT1) also renders rGAT1 responsive to hyperosmotic stimulation. Immunohistochemical analyses show that MasIne and Drosophila Ine have similar tissue distribution patterns, suggesting functional identity. Inebriated is expressed in tissues and cells actively involved in K(+) transport, which suggests that it may have a role in ion transport, particularly of K(+). We propose that stimulation of MasIne releases intracellular Ca(2+) in native tissues, activating Ca(2+)-dependent K(+) channels, and leading to K(+) transport.

Amino Acid Sequence↗
PubMed2000

Transpedicular approaches to cervical uncovertebral osteophytes causing radiculopathy.

OBJECT: The anterolateral and posterior transpedicular foraminotomies were developed to enhance the treatment of cervical spondylotic radiculopathy secondary to uncovertebral osteophytes. These novel surgical approaches may be advantageous because they allow direct decompression of the nerve root while preserving normal movement and stability of the motion segment. The use of the pedicle to obtain access to compressive uncovertebral osteophytes, without causing damage to the motion segment, has not been previously reported. METHODS: The authors present the early outcome data obtained in 27 patients who underwent an anterolateral or posterior foraminotomy. Eighty-eight percent of patients who underwent anterolateral foraminotomy and 94% of those who underwent a posterior transpedicular procedure experienced complete or significant relief of brachialgia. Postoperatively none of the patients were symptomatically or neurologically worse. CONCLUSIONS: The transpedicular approach is an effective and potentially improved method of treating symptomatic cervical uncovertebral osteophytes compared with techniques previously described.

Adult↗
PubMed2000

New approach to cervical flexion deformity in ankylosing spondylitis. Case report.

The treatment of cervical fixed flexion deformity in ankylosing spondylitis presents a challenging problem that is traditionally managed by a corrective cervicothoracic osteotomy. The authors report a new approach to this problem that involves performing a two-level osteotomy at the level of maximum spinal curvature, thereby achieving complete anatomical correction in a one-stage procedure. This 48-year-old woman with ankylosing spondylitis presented with a 30-year history of progressive neck deformity that left her unable to see ahead and caused her to experience difficulty eating, drinking, and breathing on exertion. On examination, she exhibited a 90 degrees fixed flexion deformity of the cervical spine, which was maximum at C-4; this was confirmed on imaging studies. A two-level osteotomy was performed at C3-4 and C4-5 around the area of maximum spinal curvature, and the deformity was corrected by extending the head on its axis of rotation through the uncovertebral joints. The spine was stabilized using a Ransford loop. An excellent anatomical position was achieved, as was complete correction of the deformity. A two-level midcervical osteotomy performed at the level of maximum spinal curvature in ankylosing spondylitis enables complete correction of severe fixed flexion deformity in a single procedure. Preservation of the uncovertebral joints allows smooth and safe correction of the deformity about their axis of rotation.

Cervical Vertebrae↗
PubMed2000

Fractures of the medial humeral condyle in adults.

BACKGROUND/AIM OF STUDY: Fractures of the medial condyle of humerus are uncommon in adults. The aims of this study were (i) to highlight the rarity of this injury, (ii) to focus on the problems in management of cases which present late, and (iii) to compare the results of surgical excision of medial condyle with those of internal fixation. METHODS: Seven adult medial humeral condyle fractures were seen over a 10-year period. Four cases were surgically fixed within three weeks of the injury; one case refused operation. Two cases which presented late, one with an isolated trochlear fracture, and another Milch type I fracture comminution and compounding, were treated by excision of the condyle and supervised post excision physiotherapy. RESULTS: All six operated cases regained good function. The two patients with excised condyle had no significant instability and had good range of movements. The results were comparable to those managed by open reduction and internal fixation. CONCLUSIONS: Medial condyle fractures presenting early (within 3 weeks), should be managed by accurate open reduction and rigid fixation: non operative management leads to relatively poor results. In late/neglected cases, or those with extensive comminution, open reduction and fixation may lead to stiff and painful elbow, whereas excision of the condylar fragment does not lead to instability.

Adult↗
PubMed2000

Evaluation of leukergy test as an indicator of infection in hip joint in children.

This new blood test (leukergy) for infection is based on the fact that white cells agglomerate in peripheral blood of patients with inflammatory diseases. We evaluated leukergy in 25 children with proven septic arthritis of hip. It was found to be the efficient and earliest indicator of septic arthritis than the erythrocyte sedimentation rate (ESR), total leucocyte count (TLC), polymorphs and C-reactive protein (CRP). It also correlated well with the clinical severity of infection and the prognosis of disease. Thus leukergy is a simple, rapid and inexpensive slide test which was found as the best indicator profile for the presence of septic arthritis.

Arthritis, Infectious↗
PubMed1999

Molecular cloning and biological activity of ecdysis-triggering hormones in Drosophila melanogaster.

Ecdysis-triggering hormones (ETH) initiate a defined behavioral sequence leading to shedding of the insect cuticle. We have identified eth, a gene encoding peptides with ETH-like structure and biological activity in Drosophila melanogaster. The open reading frame contains three putative peptides based on canonical endopeptidase cleavage and amidation sites. Two of the predicted peptides (DrmETH1 and DrmETH2) prepared by chemical synthesis induce premature eclosion upon injection into pharate adults. The promoter region of the gene contains a direct repeat ecdysteroid response element. Identification of eth in Drosophila provides opportunities for genetic manipulation of endocrine and behavioral events underlying a stereotypic behavior.

Amino Acid Sequence↗
PubMed1999

Identification of a Manduca sexta NSF ortholog, a member of the AAA family of ATPases.

Transport between intracellular compartments requires the activity of an N-ethylmaleimide-sensitive fusion protein (NSF). NSF is a member of a growing family of ATPases regulating several membrane fusion reactions. We have cloned the NSF ortholog from the moth, Manduca sexta (MsNSF). MsNSF is highly conserved in domains critical for NSF function in vertebrates. MsNSF codes for a protein of 745 amino acids, translating to a M(r) of 83kDa in vitro. MsNSF is 72% and 61% similar in amino acid sequence to Drosophila and vertebrate NSFs, respectively. We expressed the D1 ATP domain of MsNSF toward which antibodies selective to MsNSF were generated. Affinity purified alpha-MsNSF antibodies detect a 83kDa protein which is highly enriched in nervous tissues. Levels of MsNSF expression are substantially lower in other tissues examined. Anti-MsNSF antibodies are capable of inhibiting vertebrate intra-Golgi transport of a cargo protein in vitro. The identification of NSF ortholog from Manduca, whose neuroendocrine system is well studied, should facilitate isolation of complexes involved in protein trafficking from insect models. Phylogenetic analysis of NSF and related proteins suggests that the members of the AAA family arose from different ancestors, since the ingroup was not monophyletic. Proteasomal subunits and p97 homologs form two distinct subfamilies, while NSF homologs branch in to the third.

Adenosine Triphosphatases↗
PubMed1999

Immunochemical localization of the metabotropic glutamate receptors in the rat heart.

The localization of the glutamate receptor outside of the central nervous system is becoming more evident. These receptors have been implicated in brain function and pathology. It can also be envisioned that they play a vital role in the physiology of other organs and systems. We recently reported the presence of ionotropic glutamate receptors in the rat heart. These were distributed differentially in specific cardiac structures, including nerve terminals, ganglion cells, and the conducting system. In this study, we investigated the presence and localization of the metabotropic glutamate receptors (mGluRs) in the rat heart by immunohistochemistry. The experimental data show that the mGluR 1alpha, mGLuR 2/3, and mGluR 5 are present in the rat heart. Their preferential localization includes nerve terminals, ganglion cells, and elements of the conducting system. The mGluR 5 was the only receptor located in the intercalated disks of the cardiac muscle and in the endothelial lining of the blood vessels. This preferential localization to the different components of the conducting system and cardiac neural structures suggest that they play a role in the physiology of the heart.

Animals↗
PubMed1999

Steroid induction of a peptide hormone gene leads to orchestration of a defined behavioral sequence.

At the end of each molt, insects shed the old cuticle by performing preecdysis and ecdysis behaviors. Regulation of these centrally patterned movements involves peptide signaling between endocrine Inka cells and the CNS. In Inka cells, we have identified the cDNA and gene encoding preecdysis-triggering hormone (PETH) and ecdysis-triggering hormone (ETH), which activate these behaviors. Prior to behavioral onset, rising ecdysteroid levels induce expression of the ecdysone receptor (EcR) and ETH gene in Inka cells and evoke CNS sensitivity to PETH and ETH. Subsequent ecdysteroid decline is required for peptide release, which initiates three motor patterns in specific order: PETH triggers preecdysis I, while ETH activates preecdysis II and ecdysis. The Inka cell provides a model for linking steroid regulation of peptide hormone expression and release with activation of a defined behavioral sequence.

Amino Acid Sequence↗
PubMed1999

Partial purification and characterization of Bacillus thuringiensis Cry1A toxin receptor A from Heliothis virescens and cloning of the corresponding cDNA.

Although extensively studied, the mechanism of action of insecticidal Bacillus thuringiensis Cry toxins remains elusive and requires further elucidation. Toxin receptors in the brush border membrane demand particular attention as they presumably initiate the cascade of events leading to insect mortality after toxin activation. The 170-kDa Cry1Ac toxin-binding aminopeptidase from the tobacco budworm (Heliothis virescens) was partially purified, and its corresponding cDNA was cloned. The cDNA encodes a protein with a putative glycosyl phosphatidylinositol anchor and a polythreonine stretch clustered near the C terminus with predicted O-glycosylation. Partial purification of the 170-kDa aminopeptidase also resulted in isolation of a 130-kDa protein that was immunologically identical to the 170-kDa protein, and the two proteins had identical N termini. These proteins were glycosylated, as suggested by soybean agglutinin lectin blot results. Cry1Ac toxin affinity data for the two proteins indicated that the 130-kDa protein had a higher affinity than the 170-kDa protein. The data suggest that posttranslational modifications can have a significant effect on Cry1A toxin interactions with specific insect midgut proteins.

Amino Acid Sequence↗
PubMed1998

Molecular and immunochemical characterization of the ionotropic glutamate receptors in the rat heart.

Excitatory amino acids (EAA) and glutamate receptors (GluRs) play a fundamental role in the central nervous system (CNS). Ionotropic glutamate receptors (iGluRs) are coupled to ion channels, which are classified according to their most selective agonists. These ligand-gated channels are permeable to Na+, K+, and Ca+. Interaction of EAA receptor is linked to Ca+2/Na+ influx. Influx changes lead to an action potential, which in the heart is transmitted along the cardiocyte membrane. Furthermore, the heart has a rich innervation and specialized conduction system for rapid conduction and regulation of cardiac rhythmicity. Availability of EAA receptors in the heart might be important for cardiac function. The following GluRs were cloned by isoform-specific RT-PCR from rat heart ribonucleic acid (RNA): GluR 1, GluR 3, GluR 4, GIuR 7, Ka 1, and Ka 2. Expression in cardiac tissue was confirmed by western (for anti-GluR 2/3) and northern blots (for GluR 3, NMDAR 1, and Ka 2). The anatomical distribution was investigated by immunohistochemistry. Antibodies to GluR 2/3, GluR 5/6/7, Ka 2, and NMDAR 1 showed the strongest signals. These signals were specifically localized to cardiac nerve terminals, ganglia, conducting fibers, and some to myocardiocytes particularly in the atrium. Each antibody had a specific pattern of distribution. This anatomical localization suggests that they might play a role in cardiac electrophysiology and pathology.

Animals↗
PubMed1998

Isolation of the V-ATPase A and c subunit cDNAs from mosquito midgut and Malpighian tubules.

Using conserved amino acid sequences for the design of oligonucleotide primers, we isolated cDNA clones for two subunits of the V-ATPase from the midgut and Malpighian tubules of Aedes aegypti larvae. The 3.1 kb cDNA of the A subunit of the peripheral catalytic V1 sector codes for a protein of 68.6 kDa. The protein contains conserved motifs, including an ATP/GTP binding site, found in all other A subunits. Southern analysis using the A subunit as a probe suggests the presence of only a single copy of gene in the Aedes aegypti. The 0.85 kb cDNA of the c subunit of the membrane H+ conducting V0 sector codes for a protein of kDa. This protein has four transmembrane domains and contains a conserved glutamic acid that serves as the binding site for dicyclohexylcarbodiimide. Southern analysis using the c subunit as a probe suggests the presence of more than one related gene in the genome of Aedes aegypti. Pileup analysis of various A and c subunits shows that these subunits fall into distinct clusters, including one in which all arthropod proteins are clustered.

Aedes↗
PubMed1998

A glucose-regulated protein, GRP58, is down-regulated in C57B6 mouse liver after diethylhexyl phthalate exposure.

Diethylhexyl phthalate (DEHP) is a widely used plasticizer that induces peroxisome proliferation in rodents. Prolonged exposure to DEHP results in a variety of toxic effects, the most significant of which appears to be an increased incidence of liver cancer and male reproductive toxicity in rodents. Accompanying these toxic effects is the induction of a number of genes within the liver, particularly those genes involved in peroxisomal fatty acid beta-oxidation and members of the cytochrome P450 family, CYP4A. In order to explore which additional genes may be altered by DEHP exposure, mRNA differential display was performed using total liver RNA from male C57B6 mice that were treated with either O or 2% DEHP in their diet for 7 days. In doing so, a number of partial cDNAs representing messages that are potentially differentially expressed have been isolated. One of these cDNAs was found to be similar to the previously cloned gene, GRP58. Analysis by RNase protection assay and North hybridization have shown that the transcript for GRP58 is down-regulated in the liver after DEHP exposure. Analysis of dose-response exposures to DEHP by reverse transcription (RT)-PCR confirm these results and also shows that GRP58 is not altered in kidney or testis. Immunoblot analysis using GRP58-specific antibodies also shows a decrease in GRP58 protein levels in DEHP-treated mice. Moreover, exposure of mice to another peroxisome proliferator, clofibrate, results in a slight down-regulation of GRP58 at the highest dose, 0.5%. Thus, it appears as if DEHP and clofibrate can use different pathways to affect gene expression.

Animals↗
PubMed1998

Arteriovenous malformation of knee masquerading as juvenile arthritis.

This is a rare case of involvement of knee joint by an arteriovenous malformation. A nine year old girl had recurrent monoarticular pain and swelling of long duration and had been treated as juvenile rheumatoid arthritis. Angiographic and histological features suggested an arteriovenous malformation of lower thigh with knee joint involvement.

Angiography↗
PubMed1998

Odontoid process and C1-C2 corrective osteotomy through a posterior approach: technical case report.

OBJECTIVE AND IMPORTANCE: To demonstrate a new posterior approach to the anterior elements of the atlas and the axis including the odontoid process. CLINICAL PRESENTATION: A 36-year-old woman presented with ankylosing spondylitis and severe flexion deformity of the cervical spine. She had sustained a trauma 5 years previously, causing the inability to look forward or to open the jaw adequately. An examination demonstrated fixed flexion and rotation of the cervical spine, with no neurological deficit. Radiologically, there was fusion of C1, C2, and the clivus. TECHNIQUE: The upper cervical vertebrae were exposed via a midline posterior incision, the posterior arch of C1 was excised, and the vertebral arteries were mobilized. A wedge osteotomy was performed through the lateral masses of C1 and subsequently through the odontoid. The head was repositioned, and C1-C2 lateral mass screws and a Ransford loop were inserted. CONCLUSION: It is possible to gain sufficient surgical access to the odontoid process via a posterior approach. The technique described is of benefit when the alternative anterior approaches to the upper cervical spine are technically difficult or impossible.

Adult↗
PubMed1998

Cloning of the V-ATPase B subunit cDNA from Culex quinquefasciatus and expression of the B and C subunits in mosquitoes.

The V-ATPase B subunit cDNA isolated from the midgut and Malpighian tubules of Culex quinquefasciatus larvae has a 1476 bp ORF encoding a 492 amino acids protein with a predicted mass of 54.8 kDa. Northern blot analysis reveals the presence of 1.8 and 4.2 kb transcripts in larvae and a 3.0 kb transcript in pupae. A single 57 kDa protein band is detected in immunoblot analysis of protein extracts from C. quinquefasciatus and A. aegypti larvae. Using antibodies to the B subunits we demonstrate high-level expression of these subunits in ion-transporting cells of caeca and anterior midgut, and in Malpighian tubules and rectum. High V-ATPase expression was also observed in the larval salivary glands, central nervous system neurophile, the thoracic endocrine complex and in imaginal discs.

Aedes↗