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Biomedical subjects

J Cunningham

Publications and source records attributed to J Cunningham.

At least 271 records · Page 15Linked to original sources
PubMedDate not supplied

Interest in different forms of self-help in a general population sample of drinkers.

The study investigates: (1) the level of interest in self-help services for drinkers, and (2) the predictors of interest in these services. A representative sample of 1,557 Ontario respondents participated in a telephone survey. Current drinkers (n=1,247) were asked about their interest in getting: (a) a telephone call from a therapist to help them evaluate their drinking, (b) a self-help book, and (c) a computerized summary comparing their drinking to that of other Canadians. Bivariate comparisons of demographic and drinking-related variables were made between those interested and not interested in each of the offered services. Logistic regression analysis was used to find the best predictors of interest. The results revealed that 16% were interested in a telephone call, 26% in a self-help book, and 39% in computerized normative feedback. Negative consequences of drinking and indicators of lower societal resources increased interest in self-help services. Computerized feedback and self-help books serve as cheap and nonintrusive ways to provide incentive for change to early-stage problem drinkers due to the interest they raise in the intended target population.

Adult↗
PubMedDate not supplied

The clinical wear of three posterior composites.

The wear of three posterior composites and two amalgams was assessed clinically and measured on replica models. For the composite restorations abrasion was measured as the depth of enamel exposed at the cavity margin. Attrition was measured for all materials as the depth of surface wear determined by laser interfereometry. For the posterior composites the mean abrasion was: Clearfil 79.2 microns, Occlusin 175.9 microns and P-30 96.1 microns. The corresponding values for attrition were: 153.4 microns, 205.9 microns and 255.5 microns, respectively. The attrition of the two amalgams was: New True Dentalloy 120.8 microns, Solila Nova 115.3 microns. Therefore, attrition was greater than abrasion and the attrition of the three composites was greater than that of the two amalgams. Abrasion was affected by local factors, including the marginal contour of the restoration, whereas attrition was largely a function of the properties of the material itself. These findings indicate that composites should not be considered as a direct alternative to amalgam, especially in patients with high occlusal stress.

Analysis of Variance↗
PubMedDate not supplied

Are parathyroidectomies still appropriate in chronic dialysis patients?

The uremic milieu generates chronic stimulatory input to the parathyroid glands, which is mediated principally by low calcium, high phosphate and low calcitriol, and results in increased parathyroid hormone (PTH) synthesis and release and an increase in parathyroid mitotic activity with the development of monoclonal areas of nodular hyperplasia. Such glands do not fully express the machinery required to mediate the suppressive inputs to the parathyroids; the extracellular calcium receptor (CaR) and the vitamin D receptor (VDR) are both downregulated. In most of these patients ablation, by parathyroidectomy or ethanol injection, provides the only means of correcting the hyperparathyroidism; apoptosis in parathyroid cells is negligible and clinically irrelevant. In practice, surgery is often delayed by a doomed and ultimately futile attempt to effect control by medical means. Better predictors of the likely success or failure of optimal non surgical management are needed. Gland size exceeding 1 cm3 and elevated PTH despite hypercalcemia (implying loss of suppressibility by calcium), in the presence of good phosphate control and adequate calcitriol provision point strongly to eventual failure of medical treatment and the need for parathyroid ablation. Parathyroidectomy, usually subtotal, remains the standard management, with ultrasound guided injection of ethanol or calcitriol showing promise in some centers. The above scenario is unlikely to be changed greatly by the new emerging vitamin D metabolites, but calcimimetic agents may well increase the scope of non surgical management.

Humans↗
PubMedDate not supplied

Maturation of the mismatch negativity: effects of profound deafness and cochlear implant use.

The use of cochlear implants to restore auditory sensation in deaf children is increasing, with a trend toward earlier implantation. However, little is known about how auditory deprivation and subsequent cochlear implant use affect the maturing human central auditory system. Our previous studies have demonstrated that the obligatory auditory evoked potentials (AEPs) of implanted children are very different from those of normal-hearing children. Unlike the obligatory potentials, which primarily reflect neural responses to stimulus onset, the mismatch negativity (MMN) provides a neurophysiological measure of auditory short-term memory and discrimination processes. The purpose of this investigation is to review our studies of the effects of auditory deprivation due to profound deafness and cochlear implant use on the maturation of the MMN in children, placed in the context of overall age-related changes in the AEPs. The development and application of a statistical technique to assess the MMN in individuals is also reviewed. Results show that although the morphology of the obligatory AEPs is substantially altered by the absence of a normal N(1) peak, the MMN is robustly present in a group of implanted children who have good spoken language perception through their device. Differences exist in the scalp distribution of the MMN between implanted and normal-hearing children. Specifically, the MMN appears to be more symmetrical in amplitude over both hemispheres, whereas it is initially much larger over the contralateral hemisphere in normal-hearing children. These findings suggest that, compared to N(1), the MMN is a better measure of basic auditory processes necessary for the development of spoken language perception skills in profoundly deaf children and adults who use a cochlear implant.

Adult↗
PubMedDate not supplied

Distribution of AAV-TK following intracranial convection-enhanced delivery into rats.

Adeno-associated virus (AAV)-based vectors are being tested in animal models as viable treatments for glioma and neurodegenerative disease and could potentially be employed to target a variety of central nervous system disorders. The relationship between dose of injected vector and its resulting distribution in brain tissue has not been previously reported nor has the most efficient method of delivery been determined. Here we report that convection-enhanced delivery (CED) of 2.5 x 10(8), 2.5 x 10(9), or 2.5 x 10(10) particles of AAV-thymidine kinase (AAV-TK) into rat brain revealed a clear dose response. In the high-dose group, a volume of 300 mm3 of brain tissue was partially transduced. Results showed that infusion pump and subcutaneous osmotic pumps were both capable of delivering vector via CED and that total particle number was the most important determining factor in obtaining efficient expression. Results further showed differences in histopathology between the delivery groups. While administration of vector using infusion pump had relatively benign effects, the use of osmotic pumps resulted in notable toxicity to the surrounding brain tissue. To determine tissue distribution of vector following intracranial delivery, PCR analysis was performed on tissues from rats that received high doses of AAV-TK. Three weeks following CED, vector could be detected in both hemispheres of the brain, spinal cord, spleen, and kidney.

Animals↗
PubMedDate not supplied

Simulations of a fox-rabies epidemic on an island using space-time finite elements.

The two-dimensional reaction diffusion equations for the spread of rabies in a logistically growing fox population are solved numerically. The method, based upon Galerkin's approach, uses space-time finite elements. The numerical model is shown, quantitatively, to possess the essential features of earlier one and two-dimensional models and to reproduce the values of field data accurately. A more realistic illustration of the use of the model, a study of the spread of rabies over the Isle of Anglesey, is then discussed.

Animals↗
PubMedDate not supplied

Nurses' attitudes to the extension and expansion of their clinical roles.

Nurses are increasingly being asked to extend or expand their traditional roles, often for reasons other than their own professional development. This study, across three specialties in one hospital, examines whether or not nurses view such change in a positive light.

Attitude of Health Personnel↗
PubMedDate not supplied

A case report: recognizing factitious injuries secondary to multiple eating disorders.

This report describes the uncommon problem of a female patient diagnosed with an eating disorder, bulimia nervosa, who reported self-mutilating dental factitious behavior. The case presents a serious diagnostic and management problem. Notwithstanding the clinical appearance of the dentition, a thorough medical-dental history was essential for this uncommon diagnosis.

Adolescent↗
PubMedDate not supplied

Surgical management of infected median sternotomy: closed irrigation vs. muscle flaps.

Mediastinitis remains a serious complication of median sternotomy which requires prompt and aggressive surgical management. Debridement and closed irrigation has been the conventional mode of treatment. Failure to respond results in open drainage and delayed healing with its associated increased morbidity and mortality. Secondary closure with rectus muscle flaps has been a marked advance in the treatment of these patients. In an attempt to define guidelines for the treatment of mediastinitis complicating median sternotomy, a retrospective review of 2,400 cardiac surgical cases at St. Vincent's Hospital from 1977 through 1982 was performed. There were 25 cases (1%) of mediastinitis. Debridement and closed irrigation was successful in 16 patients (64%) with an average postoperative hospital stay of 19 days. Failure resulted in open drainage in 2 patients (8%) with an average hospital stay of 66 days and debridement and secondary closure by rectus muscle flaps in 7 patients (28%) with an average hospital stay of 28 days. There were no deaths in the entire series. Failure to respond to closed irrigation was not due to delay in diagnosis. The length of time between operation and the first sign of sternal dehiscence did not vary significantly. Sternal dissolution, the presence of anaerobic organisms, large volumes of purulent and necrotic material, however, were responsible for continued mediastinitis and further sternal dehiscence. Open irrigation and delayed closure with muscle flaps should be reserved for these patients and appears to decrease significantly morbidity and length of hospital stay. Surgical debridement and closed irrigation, however, remains the primary method of treatment of the less virulent forms of mediastinitis following median sternotomy.

Debridement↗