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Biomedical subjects

C Sinclair

Publications and source records attributed to C Sinclair.

At least 37 records · Page 2Linked to original sources
PubMed1995

Optimizing muscle synchronization after dynamic cardiomyoplasty. Two educational cases.

Muscle stimulator programming is fundamental in ensuring optimal latissimus dorsi graft function after cardiomyoplasty. The ventricle-muscle synchronization delay has a significant effect on graft function, but can be difficult to optimize. The established method for ensuring appropriate synchronization involves the use of M-mode echocardiography. We present two educational cases in which M-mode and Doppler echocardiography have been instrumental in illustrating electrophysiologic and haemodynamic factors which need to be considered in evaluating an appropriate synchronization delay.

Atrial Fibrillation↗
PubMed1994

Peripheral deafferentation alters calcitonin gene-related peptide mRNA expression in visceral sensory neurons of the nodose and petrosal ganglia.

Visceral sensory neurons of the glossopharyngeal and vagus nerves are located in the petrosal and nodose ganglia, respectively. Our previous studies showed that peripheral axotomy which removes afferent input to visceral sensory perikarya decreased the number of calcitonin gene-related peptide (CGRP)-immunoreactive (ir) neurons in the petrosal but not the nodose ganglion. To evaluate axotomy-induced changes in CGRP mRNA expression, we used in situ hybridization histochemistry with 35S-labeled oligonucleotide probes. CGRP mRNA-containing neurons were studied 1, 3, 7 and 14 days after peripheral deafferentation of the left nodose and petrosal ganglia via transection of the left cervical vagus, superior laryngeal, glossopharyngeal and carotid sinus nerves. The numbers of CGRP mRNA-containing neurons in the deafferented petrosal ganglion were significantly reduced at 3, 7 and 14 days compared to either intact or sham-operated control ganglia. However, the density of hybridization product in the positively-labeled petrosal ganglion cells was not significantly changed. The numbers of CGRP mRNA-containing neurons in the deafferented nodose ganglion were significantly reduced at 3 and 7 days. These data suggest that axotomy-induced changes in CGRP-ir neurons of the petrosal ganglion correlate with changes in CGRP mRNA and probably result from altered CGRP gene expression. In addition, in situ hybridization histochemistry revealed changes in CGRP neurons of the nodose ganglion which were not apparent with immunocytochemistry.

Afferent Pathways↗
PubMed1994

Plasticity of tyrosine hydroxylase and vasoactive intestinal peptide messenger RNAs in visceral afferent neurons of the nodose ganglion upon axotomy-induced deafferentation.

The nodose ganglion contains placode-derived visceral sensory neurons of the vagus nerve. Previous study showed that axotomy-induced deafferentation reduced the number of tyrosine hydroxylase-immunoreactive and increased the number of vasoactive intestinal peptide-immunoreactive neurons in the ganglion. The present study was conducted to determine whether the changes in neuropeptide/neurotransmitter enzyme content are associated with changes in the expression of tyrosine hydroxylase and vasoactive intestinal peptide messenger RNAs in the nodose ganglion. We used in situ hybridization histochemistry with 35S-labeled oligonucleotide probes for tyrosine hydroxylase and vasoactive intestinal peptide precursor messenger RNAs. Peripheral axotomy of visceral afferent inputs reduced tyrosine hydroxylase messenger RNA and increased vasoactive intestinal peptide messenger RNA expression in neurons of the nodose ganglion of the rat. The number of tyrosine hydroxylase messenger RNA-containing neurons was significantly reduced at three, seven and 14 days after axotomy-induced deafferentation compared with intact and sham-operated controls. Labeling density of tyrosine hydroxylase messenger RNA-containing neurons was significantly reduced at three and seven days. Conversely, the number of vasoactive intestinal peptide messenger RNA-containing neurons increased significantly at three, seven and 14 days, while the labeling density of vasoactive intestinal peptide messenger RNA-containing neurons also increased at one, three, seven and 14 days. The results of the present study indicate that the axotomy-induced down-regulation of tyrosine hydroxylase and up-regulation of vasoactive intestinal peptide in the neurons of the nodose ganglion are associated with changes in their messenger RNAs in response to axotomy-induced deafferentation.

Animals↗
PubMed1994

Immune response to human papillomavirus type 16 E6 gene in a live vaccinia vector.

Immunization of mice with a recombinant vaccinia virus expressing the human papillomavirus type 16 (HPV-16) E6 gene elicits specific antibody, proliferative and cytotoxic T lymphocyte responses. T and B cell epitopes were mapped by using synthetic peptides. This study provides the background to future investigation aimed at developing prophylactic and therapeutic vaccines against HPV-16 infection and cervical cancer.

Amino Acid Sequence↗
PubMed1993

Caries incidence in patients with dementia.

One in ten persons over the age of 65 and as many as half the population aged 85 and over have Alzheimer's disease. Review of the literature reveals substantial decrements in oral health in persons with dementia as measured by denture hygiene, coronal decayed, missing and filled teeth, filled teeth (cervical), percentage of the population with caries, Oral Hygiene Index-simplified, and of sites with plaque, gingival bleeding and calculus. A study of caries incidence is described in 23 male veterans with moderate and advanced dementia of the Alzheimer's type, using a comparison group of male veterans from the Department of Veterans Affairs Dental Longitudinal Study, matching 2:1 for age, number of teeth and education. Baseline findings indicate significant differences in the numbers of coronal surfaces with decay, root decayed and/or filled teeth and root decayed and/or filled surfaces. Mean annual increments of coronal caries in the dementia group were 2.29 +/- 4.29 per 100 surfaces at risk, over twice that in the comparison group (0.88 +/- 1.14). For root caries, mean annual increments in the dementia group were 2.38 +/- 5.57 per 100 available surfaces, versus 0.31 +/- 0.69 in the comparison group. Despite these large mean differences, the marked variability in these small samples statistical significance in caries increments between the two groups. The article concludes by suggesting some potential modifications to clinical trials of caries preventive agents and some overall research issues in populations with dementia.

Aged↗
PubMed1992

Induction of cytotoxic T lymphocytes with peptides in vitro: identification of candidate T-cell epitopes in human papilloma virus.

A set of overlapping peptides corresponding to the L1, E6, and E7 proteins of human papilloma virus 16 was tested for their ability to bind to major histocompatibility complex class I molecules and to stimulate cytotoxic T-lymphocyte (CTL) responses in vitro. A class I binding assay using intact RMA-S cells showed that 20 of the 99 human papilloma virus peptides bound to H-2Kb and/or Db molecules. Fifteen of the 20 class I-binding peptides stimulated primary CTL responses, whereas peptides that were negative in the binding assay failed to do so. Peptide-induced CTLs recognized the immunizing peptide very efficiently, requiring no more than 1-10 nM peptide for target cell lysis. However, two observations were made that have important implications for the design of peptide-based vaccines for inducing CTLs. (i) Not all major histocompatibility complex-binding peptides that contained known motifs characteristic of naturally processed peptides induced CTLs. (ii) The efficiency of CTL lysis was strongly decreased when the size of the target peptide differed by only one amino acid residue from that of the immunizing peptide. We conclude that peptides chosen for vaccination must correspond in length to naturally processed peptides.

Animals↗
PubMed1991

Preliminary results of left heart bypass in pigs using a heparin-coated centrifugal pump.

To assess the feasibility of left ventricular assist without systemic heparinization, we used a commercially available (Sarns 3M) centrifugal pump with tubing set and cannulas, all internally precoated for the purpose of this study with heparin, to bypass the left ventricle in 12 pigs for periods of either 1 or 3 hours. There was no significant activation of clotting and there was no sign of generalized embolization. However, on postmortem studies, 5 kidneys out of 22 examined showed signs of minimal thromboembolism. This experiment shows that artificial left ventricular assist, free of systemic heparinization but using heparin precoating, is feasible and safe, at least for a short period of time.

Animals↗
PubMed1984

Model for teaching insertion of chest tubes.

Closed-chest thoracostomy with tube drainage is recognized as a necessary skill for primary care physicians. The usual teaching methods used to train medical students and resident physicians involve either instruction on patients or the use of costly animal models. An inexpensive model using commonly available materials to teach this skill is described.

Family Practice↗
PubMed1980

Night in a county ER.

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Emergency Service, Hospital↗