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Biomedical subjects

P Cain

Publications and source records attributed to P Cain.

16 recordsLinked to original sources

Recovery of chorda tympani nerve function following injury.

The chorda tympani (CT) nerve carries taste information from the anterior tongue to the brain stem. Injury to the chorda tympani may result in loss or distortion of taste information. This study examined changes occurring in the hamster peripheral taste system during recovery from injury. The hamster chorda tympani nerve was crushed in the middle ear and the animals were allowed to survive from 2 to 16 weeks. At 2 weeks, CT fibers had degenerated distal to the crush site. Up to 16 weeks after crush, there were 67% fewer myelinated fibers in regenerated nerves than in controls. The mean area of the Ca(2+)-ATPase-stained core of the fungiform taste buds was significantly smaller than in controls 2 weeks after injury, but recovered to control values by 4 weeks. Electrophysiological responses to taste stimuli were recorded from the chorda tympani distal to the injury. No responses were seen after 2 weeks; weak and unstable responses were seen after 3 weeks. By 4-8 weeks, relative responses to taste stimuli were similar to control responses, but the variability of the responses to sucrose was significantly greater than that in controls. The frequency of responses to the water rinse following taste stimuli, particularly sucrose, was also greater in the regenerated nerves. The abnormal electrophysiological responses to sucrose may be the result of the differential rate of return of fiber types and/or the transduction mechanisms. In some ways, recovery of the peripheral gustatory system after damage to the chorda tympani nerve recapitulates the later stages of taste bud development.

Animals

Improved pediatric patient flow in a general emergency department by altering triage criteria.

OBJECTIVE: To evaluate the effect of altering pediatric triage criteria on ED triage scoring and patient flow. METHODS: A prospective observational study of a pediatric triage modification was performed. Data for all pediatric patients presenting to an urban general ED during a six-month study period were collected. After the first three months, pediatric triage criteria were altered by elevating the acuity of several historical items and specifically listing abnormal signs and symptoms. Outcome measures included triage score assignment, criteria making the patient emergent, proportion of emergent or urgent triage assignments, and times to examination, disposition, and admission. RESULTS: Altering pediatric triage criteria resulted in a significant (p < 0.05) increase in the number of patients triaged as emergent (2% vs 15%) or urgent (48% vs 55%). In addition, for emergent and urgent patients there was a significant decrease (p < 0.05) in the mean times to ED examination (50 vs 44 min), floor admission (355 vs 245 min), and intensive care unit admission (221 vs 132 min). The triage changes that had a significant impact on these results were a history of color change, decreased activity, and prematurity with complications. CONCLUSIONS: A significant improvement in pediatric patient flow occurred after posting age-specific abnormal signs and symptoms as well as elevating triage acuity for specific historical clues.

Child

DNA typing of grapevines: a universal methodology and database for describing cultivars and evaluating genetic relatedness.

With established ampelographic techniques for grapevine identification it is often difficult to achieve a satisfactory, objective result. We have developed a DNA typing system using sequence-tagged microsatellite site markers as a means of differentiating cultivars of grapevine. A semi-automated analysis procedure was linked to an electronic database and found to be an objective and reliable system for cultivar identification using this simple marker type. The accumulated DNA typing data from over eighty cultivars demonstrated that cultivars that are difficult to differentiate phenotypically using ampelographic techniques can be distinguished by DNA typing. Parentage analysis uncovered errors in parent assignment or cultivar identification in specific cases. The electronic database has a conservative format to take into account the occurrence of null alleles and the possibility of missed alleles. Computer-assisted comparisons of cultivars in the database can be performed and various approaches for estimating the match probability that two unrelated cultivars have the same genotype simply due to chance are discussed. We suggest that further development of the database through international co-operation using standardised sequence-tagged site markers offers the possibility of achieving a universal grapevine identification system.

DNA, Plant

Safety considerations in a surgical robot.

This paper describes the safety features of the ROBODOC Surgical Assistant System, an image-driven robotic system which has been used to perform Total Hip Replacement surgery. These features include a dedicated processor for continuous monitoring of system status, shared data areas (dual-ported RAM), and external sensors (force-torque sensor, redundant positional encoders, and bone motion monitor).

Equipment Safety

Hydrogen peroxide stimulates the synthesis of platelet-activating factor by endothelium and induces endothelial cell-dependent neutrophil adhesion.

Oxidant-induced damage to the intima of pulmonary and systemic vessels is thought to be an important mechanism of injury in a variety of syndromes of vascular damage. Hydrogen peroxide (H2O2) is an active oxygen metabolite that may induce intimal injury by cytolytic attack or by inducing biochemical and functional alterations in the endothelial cells (EC); however, mechanisms involved in noncytolytic perturbation of EC are largely unknown. We found that H2O2 stimulated the synthesis of platelet-activating factor (PAF) by primary cultures of bovine pulmonary artery endothelium (BPAEC) and by human umbilical vein endothelium (HUVEC). In each cell type the incorporation of [3H]acetate into [3H-acetyl]PAF was concentration- and time-dependent and was temporally dissociated from severe plasma membrane disruption and cytolytic cell injury; the newly synthesized PAF remained associated with the EC. H2O2 caused permeabilization of EC to 45Ca2+ and an increase in intracellular Ca2+, suggesting that a transmembrane Ca2+ flux is the signal that initiates PAF synthesis. H2O2 also induced the endothelial cell-dependent adhesion of neutrophils to HUVEC monolayers. This response was rapid, with an onset within minutes and a subsequent time course that paralleled the time course of PAF accumulation, and was dependent on extracellular Ca2+ but not on de novo protein synthesis. These studies demonstrate that H2O2 can induce two rapid activation responses of endothelium, PAF synthesis and EC-dependent neutrophil adhesion, events that may be important in physiologic and pathologic inflammation.

Animals

Effect of halothane on the rate of acid production, lactate production and pyruvate dehydrogenase activity of malignant hyperpyrexia human muscle.

The rates of acid production were compared in thin strips of muscle biopsy samples isolated from malignant hyperpyrexia and control vastus internus human muscle. Halothane doubled the rate of acid production by malignant hyperpyrexia susceptible muscle but had no effect on control samples. This increased rate of release of acid from muscle was not from lactate. In addition, the pyruvate dehydrogenase activity of both control and malignant hyperpyrexia muscle samples was not stimulated by halothane.

Acids

[Colonoscopic follow up of rectocolonic cancer surgeries. Assessment of 64 examinations].

A collation of 64 colonoscopic examinations performed on 41 patients operated on for cancer of the colon or rectum is reported. Eleven patients (26.8 percent) had positive follow-up endoscopic findings. In 13 enumerated tumoral proliferations. 8 benign polyps and 5 malignant growths were found, one of the latter on the anastomosis, and the other 4 on the remaining colon. 80 percent of these tumoral growths and all malignant tumors were discovered in the two years following surgery. When colonic strictures present before operation prevent total colonoscopic exploration, such an endoscopic examination of the colon in its entirety must be made immediately following passage of three post-operative months. It is prudent not to wait for attendant alarming signs but rather to integrate total colonoscopy including excision of "overlooked" or newly-formed polyps into the follow-up protocol of all colon surgery cancer patients who have become high-risks for either a relapse or recurrence of polyps. In the initial two post-operative years, when there is a maximal risk. Colonoscopy should be performed every six months and thereafter at longer but regular intervals throughout survival.

Adenocarcinoma

[Multiple endocrine neoplasms associated with Zollinger-Ellison syndrome and hyperparathyroidism].

We report the case of a 43 year old man with multiple endocrine neoplasia (Zollinger-Ellison syndrome-hyperparathyroidism) diagnosed during investigations for a severe ulcer with diarrhoea. The history suggested Zollinger-Ellison syndrome, especially as basal acid production and blood gastrin levels were high. Hypercalcaemia and low blood phosphate levels suggested hyperparathyroidism, which was confirmed by ultra-sound of the neck, showing two parathyroid adenomas. The aim of treatment was two-fold: suppress the hyperparathyroidism and treat the Zollinger-Ellison syndrome. The approach is surgical in most cases, but the tumour is often impossible to remove and total gastrectomy has become rare with the progress in anti-secretory therapy. When the tumour behind a case of Zollinger-Ellison syndrome cannot be found, complementary chemotherapy is indicated. Other endocrine lesions must always be sought and the family investigated to exclude Wermer syndrome.

Adenoma