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Biomedical subjects

W Carter

Publications and source records attributed to W Carter.

17 recordsLinked to original sources
PubMed1991

Antibodies to different members of the beta 1 (CD29) integrins induce homotypic and heterotypic cellular aggregation.

Members of the beta 1 (CD29) integrin family are involved in cellular adhesion to extracellular matrix. However, there have been several reports of CD29 integrin participation in intercellular adhesion. For example, the treatment of the human T cell line Jurkat with antibodies to alpha 4 (CD49d) causes homotypic aggregation. The present report describes the induction of aggregation of Jurkat cells by antibodies to alpha 5 (CD49e) and to a lesser extent by antibodies to the common beta 1/CD29 chain of these integrins. The metabolic requirements for these aggregations are compared with that of the CD49d-induced process. The possible involvement of fibronectin in the cytoadhesion appears to be unlikely as (1) the aggregates form in the absence of plasma fibronectin; (2) antibodies to fibronectin do not inhibit the cell adhesion; and (3) exogenous fibronectin does not influence the process. One of the cognate partners involved in the CD49e-induced aggregation appears to be present on non-antibody-treated Jurkat cells as the cells are coincorporated into aggregates of anti-CD49e-stimulated cells. The adhesion does not appear to involve members of the CD2, CD3, CD4, or CD18 receptor groups. These results indicate that interaction with alpha 4, alpha 5 chain or the beta 1 chain of the CD29 integrins leads to the induction of intercellular adhesion. The possible biological significance of this process is discussed.

Animals↗
PubMed1991

Blunt trauma-induced pacemaker failure.

A 54-year-old man with an artificial pacemaker sustained blunt trauma to his chest when he was struck with a baseball bat. Within 15 minutes after the injury, the patient experienced cardiovascular collapse. His pacemaker failed, and he required insertion of a temporary transvenous pacemaker. At surgery, the defect was traced to failure of the pulse generator, a rare cause of pacemaker failure. Emergency department evaluation should include prompt and continuous ECG monitoring, an overpenetrated chest radiograph, and telemetry evaluation after discharge.

Cardiac Pacing, Artificial↗
PubMed1991

Home calls. Managing call girls.

The author presents an insight into how a general practitioner manages a patient who works as a prostitute. It portrays the medical problems, including screening and management, and highlights the human aspects of the all-important doctor-patient relationship.

Adult↗
PubMed1990

Effect of eosinophil-degranulating estrogens on spleen eosinophils and white pulp/red pulp ratio.

A role for eosinophils in the immune reaction has not been yet established. Considering that these leukocytes accumulate in lymphoid organs under glucocorticoid stimulation, we explored the possibility that they participate in the depression of immune reactions induced by these hormones and that they degranulate to exert this action. In this context, we investigated the dose effect of three estrogens on the number and degranulation of spleen red pulp eosinophils and on the percentage of spleen cross sectional area comprising white pulp. Estradiol-17 beta or 4 (OH) estradiol-17 beta increased red pulp eosinophils at low doses: 2 (OH) estradiol-17 beta increased them at a very high dose. The three estrogens degranulated the spleen eosinophils and decreased the lymphocyte containing spleen white pulp. We propose that the decrease in white pulp is a response mediated by agents released from degranulating eosinophils under the action of estrogen. Consequently, both estrogen-induced eosinophil degranulation and estrogen-induced increase in red pulp eosinophil numbers are conditions contributing to a decrease in white pulp volume. All above evidence supports the hypothesis that eosinophils are involved in immunoregulation by diminishing the number of lymphocytes contained in lymphoid organs.

Animals↗
PubMed1990

Dr Warwick Carter, medical writer.

As well as writing prolifically, the Brisbane doctor consults for 36 hours a week in his own practice and holds more than 20 seats on community, local government and AMA committees. He says the key is never to mix business with home. "Most of my income is generated not from general practice but from my other activities. Australian GPs are poorly paid. The government keeps telling people that GPs are ripping them off if they charge more than the medical rebate. The public's image of GPs is very low. The way it works now is that the more ethical you are and the more care you give to your patients, the less you earn." Warwick Carter does not known where his next challenge will lead him. He has three inflexible goals: to remain a GP, to finish his travels around the world, and not to volunteer for anything he does not enjoy.

Australia↗
PubMed1989

Introduction of information during the initial medical visit: consequences for patient follow-through with physician recommendations for medication.

While negotiation of treatment decisions in the medical visit has long been recognized as an important interviewing skill, limited work has been done to investigate how doctors and patients negotiate what information is relevant in understanding the patient's problem. In this research we tested how the introduction of information reflecting both the patient's and physician's perspective is related to the patient's adherence to physician recommendations for medication. Introduction of information was defined as bi-directional if patients independently offered information or behavior as frequently as they provided the information or exhibited behavior that physicians requested. Thirty random samples of audiotaped dialogue were used to construct estimates of introduction of information during the history, examination, and consultation phases of initial ambulatory care visits of 45 older male patients. The data demonstrate that bi-directional introduction of information during the examination segment explains more than half of the variance in patient adherence to physician recommendations for new medication. These findings support the idea that physician willingness to allow patients to contribute input may contribute to the partnership's arrival at treatment decisions that have meaning for both.

Adult↗
PubMed1989

The effect of a dentifrice containing triclosan and a copolymer on plaque formation and gingivitis: a 14-week clinical study.

One hundred eighteen male and female adult subjects were entered into a 14-week, double-blind clinical study to compare the effect of a dentifrice containing 0.3% triclosan and 2% of a copolymer of methoxyethylene and maleic acid on plaque formation and gingivitis. The subjects were stratified into two balanced groups according to baseline plaque scores. They then received an oral prophylaxis and were assigned to the use of either a placebo dentifrice or the triclosan/copolymer dentifrice for the next 14 weeks. After 6 weeks' use, the triclosan/copolymer dentifrice provided a 21.34% statistically significant (99% level of confidence) reduction in supragingival plaque deposits, as compared to the placebo dentifrice. The triclosan/copolymer dentifrice also provided a 5.49% reduction gingivitis after 6 weeks' use, as compared to the placebo dentifrice. This reduction was not statistically significant. After 14 weeks' use, the triclosan/copolymer dentifrice provided a 38.80% statistically significant (99% level of confidence) reduction in supragingival plaque deposits, as compared to the placebo dentifrice. The dentifrice containing triclosan and copolymer also provided 50.72% statistically significant (99% level of confidence) reduction in gingivitis, as compared to the placebo dentifrice. When tooth surfaces with the highest degree of plaque formation (i.e. Quigley-Hein score greater than or equal to 3) were examined at 6 weeks, the triclosan/copolymer dentifrice provided a 42.92% statistically significant (99% level of confidence) reduction in supragingival plaque deposits, as compared to the placebo dentifrice.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

Fatal esorubicin-induced cardiomyopathy: report of a case and review of the literature.

A case of fatal dilated cardiomyopathy induced by esorubicin (ESO) at a total dose of 740 mg/m2, given in 27 doses over 650 days, is reported. The sudden onset, rapid clinical deterioration, and fatal outcome are detailed. The outcome was not predicted by serial rest ejection fractions or clinical signs. The data from animal studies, phase 1 and phase 2 clinical testing, are reviewed, demonstrating the almost complete absence of reports of ESO-induced cardiotoxicity. Studies reviewing ejection fractions and myocardial biopsy scores show that ESO can be cardiotoxic and may produce fatal dilated cardiomyopathy.

Cardiomyopathies↗
PubMed1987

Lay person use of automatic external defibrillation.

The ability of lay persons to learn and retain defibrillation skills using an automatic external defibrillator (AED) was assessed. Thirty-four family members of cardiac arrest survivors were trained in CPR techniques and defibrillation, and evaluated for performance of skills immediately following training and at six-week and three-month follow-ups. All but two were successfully trained to complete three cycles of CPR interspersed with three defibrillatory shocks in an average of four minutes with the first shock delivered in an average of two minutes. Although there were decrements in the speed and quality of performance at each follow-up period (P less than .01), we conclude that most lay persons can learn to operate an AED safely and under simulated conditions provide defibrillatory shocks an average of eight minutes faster than typical response times of emergency medical technicians. These results suggest that AEDs can be placed in many homes of patients at high risk for cardiac arrest.

Adult↗
PubMed1986

Identification of cardiac arrest by emergency dispatchers.

Prompt identification of cardiac arrest by emergency dispatchers can save valuable time and increase the likelihood of successful resuscitation. The authors reviewed 516 cardiac and 146 non-cardiac calls to identify features of a probable cardiac arrest call. The results indicate that information about sex, location, and activity is of little use in the identification of cardiac arrest. When the patient is over 50 years old and the caller is emotional, the possibility of cardiac arrest is high, suggesting that questions about consciousness and breathing should be asked immediately. Additional information can be obtained or telephone cardiopulmonary resuscitation (CPR) instructions can be given after dispatch of an emergency vehicle.

Age Factors↗
PubMed1979

The CSF pressure-volume relationship before and after cardiac arrest in the cat.

The CSF pressure-volume (P-V) function was evaluated before and after cardiac arrest in 15 cats. The CSF volume change was produced by bolus loading (loading rate, greater than 0.1 mL/s) of the CSF space. Comparison of the CSF P-V function before and after cardiac arrest was made over a CSF pressure range of 5 to 46 mm Hg and for a CSF volume change of up to 9% of total CSF volume. After cardiac arrest, all CSF P-V curves were well described by the mathematical model konwn to be valid under normal physiological conditions. In eight animals, there was no significant difference between the prearrest and postarrest P-V functions. For the seven animals demonstrating a significant difference between prearrest and postarrest P-V data, all but one of the postarrest P-V curves were within the normal range. These results suggest that the shape of the CSF P-V curve is not substantially altered by cardiac arrest. We conclude that under normal circumstances material properties of brain tissue are the most important factors in determining the configuration of the CSF P-V curve and that under normal circumstances cerebral hemodynamic factors do not affect the shape of this curve.

Animals↗
PubMed1979

Bolous versus steady-state infusion for determination of CSF outflow resistance.

For rapid changes in cerebrospinal fluid volume an exponential relationship was demonstrated between CSF pressure and CSF volume in 15 cats. This relationship was valid over a CSF pressure range from 7 to 50 mm Hg and for acute increases of up to 9% to total CSF volume (approximately 13 ml for humans). Our data agree well with previous reports for the cat. A similar relationship has been shown in the dog and in humans. It has been claimed that, given the equations for CSF bulk flow and the exponential relationship between CSF pressure and CSF volume, one can calculate CSF outflow resistance by observing the decay of CSF pressure after a bolus injection into the CSF space. This claim was evaluated in an additional 18 cats. In these animals CSF outflow resistance calculated by the bolus method was compared with resistance calculated by a steady-state infusion method over the CSF outflow resistance range of 74 to 293 mm Hg/ml min-1. Resistance calculated by the bolus method underestimated resistance calculated by the steady-state method, and this underestimate grew larger with increasing resistance. The bolus technique is therefore not a valid method for determining CSF outflow resistance. The explanation offered for these results is that the decay of CSF pressure after a bolus injection into the CSF space occurs not only because of runoff of the injected volume of CSF but also because of "pressure relaxation" of the brain parenchyma around the CSF space. The phenomenon of pressure relaxation was not considered in developing the equation for calculation of CSF outflow resistance by the bolus technique. The time dependency of pressure relaxation allows for a fundamental element of hysteresis within the CSF space. A method of quantifying this element of hysteresis is suggested.

Animals↗
PubMed1979

Repair of chest wall defects with prosthetic material.

This report summarizes our experience during a four-year period with the repair of 8 thoracic cage and 3 diaphragmatic defects requiring reinforcement with prosthetic material. Defects as large as the entire left hemidiaphragm or the right anterior chest wall including ribs two through six from the midsternum to the midaxillary line were adequately repaired. The technical approach utilized to obtain a secure, nonmobile thoracic cage involved the placement of sutures through drill holes or around ribs, rather than through the periosteum or pericostal soft tissues. Successful diaphragmatic repair was dependent on proper anchoring of the medial border of the prosthesis, placing sutures in the pericardium as necessary. Skin coverage for thoracic cage defects was achieved with widely undermined and advanced local tissue or previously delayed pedicle flaps. All patients had good evidence of chest wall stabilization after operation, and all were removed from mechanical ventilation within three days. One patient died of myocardial infarction twenty days after operation, and a second patient died later of metastatic disease. On the basis of our experience, we conclude that the range of chest wall lesions that can be surgically corrected or palliated is increased by the use of prosthetics implanted with techniques described here.

Adult↗
PubMed1976

Re-examination of porcine and bovine hypothalamic fractions for additional luteinizing hormone and follicle stimulating hormone-releasing activities.

More than 150 hypothalamic fractions were reassayed for luteinizing hormone-releasing hormone (LHRH) and follicle stimulating hormone-releasing hormone (FSHRH) activities in search for LHRH and FSHRH which differ from the decapeptide (pyro)Glu-His-Trp-Ser-Try-Gly-Leu-Arg-Pro-Gly-NH2 (I). Among the porcine fractions tested were those obtained: 1) from the isolation of thyrotropin-releasing hormone; 2) from two isolation procedures for LHRH; and 3) from methanolic and aqueous 2N acetic acid extracts which were subjected to Biogel P-2 filtration and partition chromatography. Some bovine hypothalamic fractions were also tested. Both in vivo and in vitro assays were used for measuring LHRH and FSHRH activities. The values obtained were in each case compared with those resulting from the administration of pure natural or synthetic LHRH decapeptide I. A radioimmunoassay for LHRH (I) was also utilized for some fractions. In all the purification steps the location of LHRH and FSHRH activity, as determined by in vivo assays, corresponded to that of the decapeptide I. Purification of hypothalamic extracts on Biogel P-2 and by partition chromatography separated a fraction from the decapeptide I, which released more FSH than LH in vitro from the pituitaries of immature female rats. However, this material was inactive in vivo and in other in vitro systems, so that its significance is obscure. The results suggest that if material with LHRH and FSHRH activity other than the decapeptide I is present in acid extracts of porcine hypothalami, then its FSHRH and LHRH activity would be a minor part of the total LHRH/FSHRH activity in the extracts. (Pyro)-Glu-His-Trp-Ser-Tyr-Gly-Leu-Arg-Pro-Gly-NH2 appears to account for most of all of the LHRH and FSHRH activity found.

Animals↗
PubMedDate not supplied

Evaluating clinical accuracy of systems for self-monitoring of blood glucose.

Although the scientific literature contains numerous reports of the statistical accuracy of systems for self-monitoring of blood glucose (SMBG), most of these studies determine accuracy in ways that may not be clinically useful. We have developed an error grid analysis (EGA), which describes the clinical accuracy of SMBG systems over the entire range of blood glucose values, taking into account 1) the absolute value of the system-generated glucose value, 2) the absolute value of the reference blood glucose value, 3) the relative difference between these two values, and 4) the clinical significance of this difference. The EGA of accuracy of five different reflectance meters (Eyetone, Dextrometer, Glucometer I, Glucometer II, Memory Glucometer II), a visually interpretable glucose reagent strip (Glucostix), and filter-paper spot glucose determinations is presented. In addition, reanalyses of a laboratory comparison of three reflectance meters (Accucheck II, Glucometer II, Glucoscan 9000) and of two previously published studies comparing the accuracy of five different reflectance meters with EGA is described. EGA provides the practitioner and the researcher with a clinically meaningful method for evaluating the accuracy of blood glucose values generated with various monitoring systems and for analyzing the clinical implications of previously published data.

Blood Glucose↗