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Biomedical subjects

J Henderson

Publications and source records attributed to J Henderson.

At least 181 records · Page 10Linked to original sources
PubMed1990

A comparative rewarming trial of gastric versus peritoneal lavage in a hypothermic model.

A comparison of gastric lavage versus peritoneal lavage rewarming was studied in a hypothermic rabbit model. The gastric lavage group (n = 5) had a mean rewarming time of 136 +/- 25.1 minutes versus the peritoneal lavage group (n = 6) mean rewarming time of 131.7 +/- 27.9 minutes (p = .795). Good correlation was found between tympanic membrane temperature readings and both rectal temperature readings (r = .69) in the gastric lavage group and esophageal temperature readings (r = .90) in the peritoneal lavage group. Gastric lavage and peritoneal lavage have the same rewarming rates in the present hypothermic model.

Animals↗
PubMed1990

Mobile breast screening: factors affecting uptake, efforts to increase response and acceptability.

In 1986, a breast screening project was set up to assess the feasibility of mobile breast screening in rural areas near Edinburgh. Secondary objectives included a study of factors affecting uptake, ways in which uptake might be encouraged and a study of the acceptability of this form of screening. This paper deals with the results of studies dealing with secondary objectives. We found that response rates to opportunistic screening was poor, 5,631 attenders out of 23,229 eligible women (24.2%). This was especially so in older women. Distance proved to be the single most significant factor affecting uptake, but car and house ownership were also highly significantly correlated with response. Leaflet drops had no demonstrable effect on response, but personal invitation by general practitioners produced a 75% response rate in women 50-64 who had failed to attend on the van's previous visit. Attenders found this form of screening both convenient and acceptable.

Adult↗
PubMed1990

Local anaesthesia for eye surgery. The peri-ocular technique.

A technique of peri-ocular infiltration of local anaesthetic for eye surgery is described. The ease of administration of this form of local blockade is highlighted and its low propensity for complication compared with retrobulbar blockade. The involvement of anaesthetists in the performance of local anaesthesia for ophthalmic surgery that utilises this technique is encouraged.

Anesthesia, Local↗
PubMed1990

Lung fibrosis induced by Thorotrast.

A 63 year old woman developed progressive shortness of breath, pulmonary hypertension, and respiratory failure and died from pulmonary fibrosis 45 years after thoracic fistulography with Thorotrast. Bouts of acute respiratory failure occurred with features of noncardiogenic pulmonary oedema. Lung tissue obtained by biopsy and at necropsy showed abundant radioactive particles of thorium dioxide in the lungs. The particles were congregated in the walls of blood vessels and in perivascular fibrous zones, consistent with a causal role of Thorotrast in the development of lung fibrosis. It is suggested that the fibrosis was due to the combined effects of alpha radiation on the interstitial perivascular zones and of recurrent pulmonary oedema due to endothelial damage.

Autoradiography↗
PubMed1990

Effects of passive immunization against parathyroid hormone (PTH)-like peptide and PTH in hypercalcemic tumor-bearing rats and normocalcemic controls.

Passive immunization using antisera raised against rat PTH-like peptide [PLP-(1-34)] and rat PTH-(1-84) was used to assess and compare the roles played by PLP and PTH in modulating mineral metabolism in hypercalcemic rats bearing the Rice-500 Leydig cell tumor and in normocalcemic control animals. After immunization, plasma calcium in the tumor-bearing animals rapidly normalized and remained within the normal range for several days, plasma phosphate rose, and urinary phosphate and cAMP fell. These changes were associated with increased longevity of the tumor-bearing rats. Reduction of plasma calcium was shown to be a function of early (5 h) neutralization of PLP bioactivity in the kidney, whereas the effect of immunoneutralization of PLP in bone appeared later (24-48 h) and was more prolonged. Immunization against PTH in normocalcemic animals resulted in a hypocalcemic episode of smaller magnitude and shorter duration than that achieved in hypercalcemic animals immunized against PLP and appeared to be unassociated with neutralization of distal tubular effects. Neutralization of proximal tubular and skeletal actions of PTH appeared to occur in a manner analogous to that seen for PLP in tumor-bearing animals, but were of shorter duration. These studies suggest that in normal animals the action of PTH in the skeleton and/or on vitamin D metabolism contributes considerably more than renal transport activity to the maintenance of normocalcemia and that compensatory mechanisms rapidly restore homeostasis. PTH appears to be the major modulator of calcium homeostasis in normal rats, with PLP playing a minor role, if any. In tumor-bearing rats, mechanisms to restore calcium levels to baseline are delayed after PLP immunoneutralization, and PLP appears to be both necessary and sufficient for the hypercalcemic state.

Animals↗
PubMed1990

Parathyroid hormone-like peptide in normal and neoplastic human endocrine tissues.

PTH-like peptide (PLP) is produced by tumors commonly associated with hypercalcemia as well as nonneoplastic tissues and several endocrine glands and tumors. To characterize the distribution of PLP in human endocrine tissues and tumors, we localized PLP in formalin-fixed paraffin-embedded material using the avidin-biotin-peroxidase technique with polyclonal antisera. Among peptide hormone-producing tissues, PLP was identified in nontumorous adenohypophysis and pituitary adenomas; medullary thyroid carcinomas; normal, hyperplastic, and adenomatous parathyroids; adrenal medulla and pheochromocytomas; normal pancreatic islets; and endocrine tumors of pancreas, gut, and lung, including small cell carcinomas. In other endocrine tissues PLP was identified in nontumorous thyroid follicular epithelium, colloid nodules, and follicular neoplasms; normal adrenal cortex, adrenocortical adenomas, and carcinomas; nontumorous testicular Leydig cells; normal ovarian granulosa and thecal cells; an ovarian thecoma and a granulosa cell tumor; placental trophoblast; and decidua. These results demonstrate that PLP is localized in many normal and neoplastic endocrine cells, including those not known to influence extracellular calcium homeostasis. The presence of PLP in a variety of endocrine tissues suggests that it may play a local physiological role in the growth or function of endocrine cells.

Adrenal Cortex Neoplasms↗
PubMed1990

Tobacco, alcohol, and marijuana use among black adolescents: a comparison across gender, grade, and school environment.

Self-report measures of tobacco, alcohol, and marijuana use were administered to 2,748 black adolescents, grades 7 through 12. The proportion of students who had tried any of the substances increased by grade. Males and females were not significantly different in their use of cigarettes and alcohol. Males were more likely to have tried smokeless tobacco, smoked marijuana, and used combinations of substances. Females who reported using more than one substance preferred the combination of cigarettes and alcohol. Significant effects of school environment were noted. Increasing age-related experimentation is exacerbated by school setting (junior high versus senior high). Given that blacks have disproportionately high cancer prevalence and mortality rates, intervention programs may also need to consider school environment, substance specific initiation points, and combined use preferences in order to maximize the desired effect within this population.

Adolescent↗
PubMed1989

Use of medical record linkage to study readmission rates.

Readmission rates after inpatient care were studied by using routinely collected data from the Oxford record linkage study for 1968-85. Discharges from hospital and subsequent admissions were identified for people who were both resident and treated in the area covered by the linkage study. Rates were calculated for readmissions within 28 days after discharge from the first, index event. Readmission rates for elective readmissions after elective index admissions rose from 3.5% in 1968 to 7.1% in 1985. Those for elective readmissions after immediate (emergency or accident) index admissions rose from 2.4% to 3.5% during the same period. Emergency readmissions after an immediate index admission rose from 4.0% to 7.0%, and emergency readmissions after an elective index admission rose from 1.3% to 2.5%. All these increases were significant. The rise in elective readmissions may in part reflect a trend towards planned discharge with the expectation of readmission. The rise in emergency readmissions, which has been fairly gradual over many years, may, in some cases, be due to pressure on resources and inappropriately short lengths of stay. Further evidence is required to confirm or refute this. Readmission rates are one of the few potential measures available from routine statistics for assessing outcome, but due consideration must be given to issues of method and interpretation.

Emergencies↗
PubMed1989

Conformation and dynamics of a left-handed Z-DNA hairpin: studies of d(CGCGCGTTTTCGCGCG) in solution.

The physical properties of the DNA oligomer d(CGCGCGTTTTCGCGCG) in solvents containing 4 M NaClO4 and 0.1 M NaCl were investigated by proton NMR, optical melting, and circular dichroism spectroscopy. Results of these investigations are as follows: (i) The DNA hexadecamer exists as a unimolecular hairpin in either high or low salt. (ii) In high salt the stem region of the hairpin is in the left-handed Z conformation. (iii) In either high or low salt, the duplex stem of the hairpin is stabilized against melting by approximately 40 degrees C compared to the linear core duplex. The added stability of the hairpin is entropic in origin. (iv) In high salt, as the temperature is elevated, the equilibrium structure of the duplex stem of the hairpin shifts from the Z to the B conformation before melting. (v) In low salt, when the DNA duplex exists in the B conformation, attachment of a T4 single-strand loop to one end only slightly decreases (by 14%) the correlation time of the CH5-CH6 interproton vector. In high salt, when the DNA duplex exists in the Z conformation, the correlation time of the CH5-CH6 interproton vector decreases by 51%. Since these viscosity-corrected correlation times are taken to be indicators of duplex motions on the nanosecond time scale, this result directly suggests a larger amplitude of these motions is present in the duplex stem of the hairpin when it exists in the Z conformation.

Circular Dichroism↗
PubMed1989

Elective total parathyroidectomy without autotransplant in end-stage renal disease.

Ten patients are reported following parathyroidectomy (PTX). In 9 all identifiable parathyroid tissue in the neck was deliberately removed, and in the tenth (operated 14 years ago) the remnant which had been left probably did not function. Their post-operative course resembled that of patients treated conventionally, and their subsequent course was likewise uneventful with disappearance of all symptoms associated with their osteodystrophy. All patients required oral calcium supplementation but none were given vitamin D compounds after the initial period of repletion following surgery. Mean serum values were (before PTX and current) for calcium 2.63 +/- 0.14 and 2.33 +/- 0.08 mmol/liter, P = NS, for phosphorus 1.96 +/- 0.13 and 1.38 +/- 0.09 mmol/liter, P less than 0.01, and for alkaline phosphatase 713 +/- 191 and 101 +/- 14 IU, P less than 0.05. Evidence for residual parathyroid tissue was present in each case; one patient remained mildly hyperparathyroid and several were mildly hypoparathyroid by the IRMA PTH assay. Bone histomorphometry in five subjects post-PTX showed either normal or low turnover. Radiologically, striking remineralization was seen with disappearance of all erosive changes. We suggest that residual areas of parathyroid tissue are stimulated and continue to secrete hormone even when all the discrete glands have been removed. It is recommended that when indicated, and in the absence of aluminum excess, total PTX without autotransplant should be the preferred form of therapy for long-term dialysis patients.

Adult↗
PubMed1989

Day case surgery: geographical variation, trends and readmission rates.

Data from the Oxford Record Linkage Study were analysed to determine the amount of work undertaken in day case surgery for 12 surgical conditions in five districts in the Oxford Region during the years 1976 to 1985. Record linkage was used to study readmission rates, comparing day surgery with inpatient care. The use of day surgery gradually increased in some conditions (eg, termination of pregnancy, female sterilisation) but did not increase from a fairly low base for others (eg, inguinal hernia repair, operations on varicose veins and haemorrhoids). There were striking differences between the districts in the use of day case care. For example, the use of day case care as a percentage of all hospital admissions for termination of pregnancy varied from 1% in one district to 24% in another; that for dilatation and curettage varied from 1% to 43%; and that for female sterilisation varied from less than 1% to 35%. Emergency readmission rates after day surgery were similar to those following inpatient treatment. We conclude that the use of day surgery for some conditions judged suitable for day care is still low and, even within one region, variation in the use of day surgery is considerable. The reasons for continued reluctance in some places to undertake more day surgery merit investigation.

Ambulatory Surgical Procedures↗
PubMed1989

The parathyroid hormone-like peptide gene is expressed in the normal and neoplastic human endocrine pancreas.

PTH-like peptide (PLP) is produced by a number of tumors commonly associated with the development of hypercalcemia. Analysis of the expression of the PLP gene has demonstrated that a variety of non-neoplastic endocrine and nonendocrine tissues contain PLP mRNA transcripts. Using a combination of Northern blot analysis, immunohistochemistry, and RIAs, we have demonstrated that the PLP gene is expressed in normal human and rat fetal and adult islets of Langerhans. PLP gene expression was not confined to cells containing a single pancreatic islet hormone, but was found in cells of all four major endocrine subtypes. PLP mRNA transcripts were also detected in RNA prepared from isolated rat islets, and small amounts of PLP immunoreactivity were secreted by cultured rat islets. Fifteen human pancreatic endocrine tumors not associated with hypercalcemia were analyzed and PLP-immunopositive tumor cells were found in 13. These observations demonstrate that the PLP gene is expressed in the normal and neoplastic islets of Langerhans, and suggests a possible role for this peptide in the growth or function of the endocrine pancreas.

Adult↗
PubMed1988

Glycemic control and raised serum alanine aminotransferase activity in treated diabetes mellitus.

The prevalence of raised serum liver-associated enzyme activity in stabilised, treated diabetic outpatients without concurrent hepatobiliary disease was investigated using a retrospective computer search of biochemical data. The frequency of raised alanine aminotransferase, aspartate aminotransferase, or gamma glutamyl transferase activity found among diabetic, general medical and respiratory outpatients was compared with that found in apparently healthy controls. It was established that a raised activity of any of the three enzymes occurred with a similar frequency in each outpatient group. However, only with alanine aminotransferase did the frequency of elevation (7.1%) in the patients with previously diagnosed hepatobiliary disease exceed that of healthy controls. A raised alanine aminotransferase activity in diabetic outpatients was associated with good glycemic control (hemoglobin A1 less than 8%, p less than 0.02) and treatment with oral hypoglycaemic agents (p less than 0.001).

Alanine Transaminase↗
PubMed1988

Direct functional assessment of human osteoblasts by radioautography: methodology and application in end stage renal disease.

Fragments approximately 1 mm3 of freshly obtained iliac crest cancellous bone were incubated for 30 minutes at 37 degrees C in Krebs buffer containing 3H-leucine or 3H-proline followed by radioautography. Grains per osteoblast, reflective of protein synthetic activity, were counted in normal controls and patients with end stage renal disease with or without significant aluminum storage in their bones. Compared with control the end stage renal disease patients without significant aluminum storage had more large osteoblasts with increased grain counts which were ascribed to secondary hyperparathyroidism. Cells from patients with greater than 30% surface aluminum had more small osteoblasts with grain counts intermediate between control and less than 2% aluminum, ascribed to an inhibitory effect of aluminum on the secondary hyperparathyroidism. Cell activity did not depend on location next to a tetracycline label or osteoid and it was suggested that all bone lining cells could be considered as osteoblasts. Aluminum storage was associated with impaired mineralisation in the presence of normal or increased osteoblastic protein synthetic activity suggesting that in these patients the mineralisation defect was not primarily due to an abnormality in osteoblast function.

Aluminum↗