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Biomedical subjects

R C Pearson

Publications and source records attributed to R C Pearson.

At least 73 records · Page 4Linked to original sources
PubMed1990

Which agent and how to deliver it? A review of benzodiazepine sedation and its reversal in endoscopy.

Amnesia, relaxation, and cooperation, not anaesthesia, should be the clinical end points when using intravenous sedative drugs for endoscopic procedures. Diazepam has now been replaced by midazolam as the first-choice sedative agent to achieve these effects. Midazolam, when used in correct doses, is more suited to endoscopy than diazepam because of its shorter elimination half-life, larger volume of distribution, and faster total body clearance. Midazolam is also clinically superior, as it achieves amnesia in twice as many patients and at lighter levels of sedation than with diazepam. The routine use of opioids in combination with benzodiazepines is to be avoided, as it increases the likelihood of adverse cardiopulmonary events. The availability of the specific benzodiazepine antagonist, flumazenil, is not an excuse for the administration of excessive doses of benzodiazepines. Flumazenil is an essential emergency drug when benzodiazepine-induced sedation is used. Reversing single-dose benzodiazepine-induced sedation after outpatient endoscopy enables earlier accurate retention of information and earlier discharge and may have significant cost-benefit implications.

Analgesics, Opioid↗
PubMed1989

Messenger RNA encoding the D2 dopaminergic receptor detected by in situ hybridization histochemistry in rat brain.

A 30 base synthetic oligonucleotide probe was used to detect the mRNA encoding the rat D2 dopaminergic receptor. On Northern analysis, the probe identified a single species of mRNA of approximately 2.9 kb, present at highest levels in the striatum but also found in the brainstem, neocortex and diencephalon. On sections, neurons containing high levels of the mRNA were detected in the striatum, the substantia nigra pars compacta and the ventral tegmental area. Lower levels of signal were seen over neurons in the hypothalamus, the frontal neocortex, and the globus pallidus.

Animals↗
PubMed1989

Effects of inhaled municipal refuse incinerator fly ash in the guinea pig.

Fly ash was collected from two municipal refuse incinerators. It was analyzed for heavy metals, elements, and a wide range of toxic organics. It was resuspended in air for inhalation exposure of guinea pigs. These animals were exposed at high concentrations of each ash 6 h/d for 5 d, and tissues were taken 45 d after the exposure. Following the first exposure and after each daily exposure the ventilatory response of these animals upon challenge with CO2 was found to be depressed. Recovery occurred following exposure. Heavy metals, cadmium, lead, zinc, and mercury were elevated in the lungs of these animals. Histologic evaluation of pulmonary tissue revealed multifocal pneumoconiosis. Interstitial infiltration by macrophages and smooth muscle hypertrophy of blood vessels and bronchioles were also observed. There was no evidence of a dioxinlike toxic effect following inhalation of these ashes.

Air Pollutants↗
PubMed1989

Evidence that matching for HLA antigens significantly increases transplant survival in 1001 renal transplants performed in the northwest region of England.

In the 20-year period from March 1968 to March 1988, 860 patients received 1001 renal transplants in the Northwestern Regional Renal Transplant Unit at Manchester Royal Infirmary. Through a continuing policy of avoiding mismatches for HLA antigens and lymphocytotoxic antibody crossmatching, transplant survival rates were found to correlate with the degree of HLA-A and B antigen mismatching from 1968 to 1978 and with HLA-B and DR antigen mismatching from 1979 to 1988. Mismatching for HLA-B and DR antigens was also found to correlate with transplant survival in highly sensitized patients and in patients transplanted since 1981, the "cyclosporine era." Recipients who were HLA-DR1 positive were found to have the highest graft survival compared to recipients negative for this antigen. In contrast, HLA-DR3 positive recipients had the poorest outcome. Transplants from HLA-DRw6 positive donors showed higher transplant survival rates than donor kidneys positive for any other HLA-DR antigen. A correlation of transplant survival with HLA-B and DR mismatching was seen whether kidneys were collected within our region or received through the UK Transplant Service. We conclude that avoidance of mismatching for HLA-B and DR antigens confers high transplant survival rates (91.1% at 5 years for 0 HLA-B and DR mismatches), and in order to achieve this rate for most recipients exchange of donor kidneys between transplant centers will be essential.

Adolescent↗
PubMed1989

Preference for hot drinks is associated with peptic disease.

The temperature at which people chose to take a hot drink was measured in 59 patients with endoscopically proven peptic disorders of the upper gastrointestinal tract and 65 asymptomatic controls. The patients in the disease group drank significantly hotter tea or coffee than the control group (medians 62 degrees and 56 degrees Celsius respectively, P less than 0.0001). The median temperatures of choice for subgroups of patients with oesophageal, gastric or duodenal disease were significantly higher than the control group (63.5 degrees, 63 degrees, 60.5 degrees C respectively). There was no relationship between a preference for hotter drinks with either the sex or smoking habits of the patient. In the control group the temperature of choice tended to decrease with age though linear regression just failed to reach statistical significance (p = 0.06); this trend was not apparent in the disease group (p = 0.64). Thermal injury as a result of drinking hot fluids may be a causative factor in some peptic disorders.

Adult↗
PubMed1989

Olfaction and psychiatry.

Recent clinical studies have identified significant olfactory deficits in several neuropsychiatric disorders, notably Alzheimer's disease and Parkinson's disease. These have correlated with neurochemical and neuropathological studies of the olfactory system. The presence of a specific sensory deficit may be related to the localisation of pathology within the brain. There is a need for incorporation of olfactory testing into routine clinical examination.

Brain↗
PubMed1988

Tubulin messenger RNA: in situ hybridization reveals bilateral increases in hypoglossal and facial nuclei following nerve transection.

We have examined the levels of mRNA coding for tubulin in cranial nerve motor nuclei following axotomy using in situ hybridization histochemistry. Following division of their peripheral axons, the neurons in the facial and hypoglossal nuclei show increased levels of tubulin mRNA both ipsilateral and contralateral to the lesion. Tubulin in situ hybridization histochemistry provides a sensitive technique to monitor dynamics of neuronal regrowth or sprouting in the peripheral and possibly the central nervous system.

Animals↗
PubMed1988

The cortico-cortical connections within the parieto-temporal lobe of area PG,7a, in the monkey.

After injections of HRP into area PG(7a) labelled cells have been found in architectonic areas OA, PE, the cingulate and retrosplenial areas medial to area PG; posteriorly areas MST, OA (V4), V2, V3 and the cortex in the walls and floor of the superior temporal sulcus have also been labelled. Small injections placed in PG have resulted in different parts of these areas being labelled, suggesting that these cortico-cortical connections are well organized and raising the possibility of an ordered representation of the visual field in PG. It is suggested that the vertical meridian is around the boundary and the horizontal meridian passes antero-posteriorly across about the middle of its medio-lateral extent; the central part of the visual field is in the depths of the intraparietal sulcus, and the periphery is on the surface of the inferior parietal lobule and in the anterior wall of the upper part of the superior temporal sulcus. The lower visual field is medial and the upper field is lateral.

Animals↗
PubMed1988

The organization of the cortico-cortical connections between the walls of the lower part of the superior temporal sulcus and the inferior parietal lobule in the monkey.

After injections of HRP into area 7a,PG, in the monkey labelled cells have been found in the walls and floor of the lower part of the superior temporal sulcus; the part of area 7a,PG, in the posterior wall of the intraparietal sulcus is connected with the floor and posterior wall of the superior temporal sulcus, and the part of 7a,PG on the surface of the inferior parietal lobule with the floor and anterior wall. Area 7b,PF is related to a restricted part of the floor of the superior temporal sulcus.

Animals↗
PubMed1988

Brain-specific src oncogene mRNA mapped in rat brain by in situ hybridization.

Brain src protooncogene is expressed in two forms, one identical to message in other tissues, and one containing an 18-nucleotide insert specific to brain. We have mapped mRNA for the two forms of src in rat brain with selective antisense oligonucleotide probes to the brain (src+) and peripheral (src-) forms. Fetal rat src mRNA levels were much higher in the central nervous system than any peripheral organ. In adult brain, src+ mRNA level was highest in the internal granular layer of the olfactory bulb, pyramidal cells of the hippocampus, granule cells of the dentate gyrus, and cerebellar granule cells. src+ and src- levels were similar in hindbrain, but src+ levels were higher than those of src- in forebrain. These distributions suggest that src+ may play roles in a number of neural processes, possibly including neuronal plasticity.

Animals↗
PubMed1988

G protein mRNA mapped in rat brain by in situ hybridization.

Guanine nucleotide-binding regulatory proteins (G proteins) mediate many receptor-coupled signal transduction events. We have localized in rat brain by in situ hybridization the mRNA for the G protein subunits--G alpha s, G alpha o, and G beta. Oligonucleotide probes were radiolabeled by a technique that resulted in a probe of defined specific activity and uniform length. mRNA species encoding G alpha s and G beta occur in high densities heterogeneously throughout the brain, especially in large neuronal cell bodies--e.g., hippocampal pyramidal cells, granule cells of the dentate gyrus, hypothalamic nuclei, and neurons of brainstem nuclei and the reticular formation. G alpha o mRNA has a more limited distribution and abundance, being detectable in the claustrum, endopiriform nucleus, habenula, hippocampal pyramidal cells, granule cells of the dentate gyrus, and cerebellar Purkinje cells.

Animals↗
PubMed1988

Multichannel digital recording of intraluminal temperature in the upper gastrointestinal tract of man: techniques and analyses.

A recording system has been developed to measure intraluminal temperature changes from six sites simultaneously in the upper gastrointestinal tract at rates up to 10 Hz from each site. The temperature probe contains six type K thermocouples mounted in 14 French gauge orogastric tube. The data is logged, after digital conversion and signal multiplexing, onto disc storage by a dedicated microcomputer. The fluctuating temperature profile, defined as temperature spikes, has been subjected to novel computer analysis to allow definition of temperature load and dissipation within the oesophagus, stomach and duodenum. This system enables the effects of drinking and eating hot and cold foods on the physiological functions of the gastrointestinal tract to be studied accurately.

Body Temperature↗
PubMed1988

The relevance of Chlamydia trachomatis in acute epididymitis in young men.

Young men presenting to a General Surgical Unit with acute epididymitis underwent microbiological investigation, including culture for Chlamydia trachomatis. The results were compared with similar investigations in an asymptomatic control population and with patients presenting to the Department of Genito-urinary Medicine with urethral discharge. Chlamydia trachomatis was cultured from 15% of patients with acute epididymitis and a further 15% had serological evidence of exposure to Chlamydia. Nearly 50% of patients attending the Genito-urinary clinic grew Chlamydia from the urethra. The background prevalence of Chlamydia in the control population was low. It is necessary to identify the significant minority of young men with acute epididymitis associated with chlamydial infection, because of the risk of pelvic inflammation and infertility in their female partners. At present this can only be achieved by submitting all young men with acute epididymitis to full microbiological investigation.

Acute Disease↗