Biomedical subjects

K Hamilton

Publications and source records attributed to K Hamilton.

77 records · Page 5Linked to original sources

PubMed1953

The co-action of estrogen in the induction of tumors of the mouse uterus treated with 20-methylcholanthrene [abstract].

Over 200 young mature and mature CF1 mice were ovariectomized and their uterine horns implanted bilaterally with circa 2 mg methylcholanthrene (MCA) by trocar. Subcutaneous injections of 20 mcg diethylstilbestrol in 0.05 ml oil were then made 3x weekly in equivalent groups for 0, 4, 6, 10, 12, 14, 16, 18, and 20 weeks. All animals died or were sacrificed by 180 days following MCA implantation. Nearly 1/2 of the 57 mice surviving estrogen treatment and living at least 100 days after MCA implantation developed uterine tumors. Most of the affected mice developed tumors in both cornua. Tumors in mice receiving estrogen for the longer periods were especially large and aggressive. Histologically, they were predominantly sarcomatous, but adenocarcinomas were induced in the approximate ratio of 1:4. The incidence of tumors in mice treated with estrogens for 12-20 weeks was significantly higher than in those given extrogen 4-10 weeks. Only 1 prominent uterine tumor was found in 8 mice which survived 102-168 days after bilateral MCA implantation and 12 subcutaneous injections of 60 mcg diethylstilbestrol in 4 weeks. Diethylstilbestrol, when administered for a sufficient period, seemingly acts as a cocarcinogen in mice, accelerating the induction of uterine tumors by MCA and perhaps stimulating their growth.

Animals, Laboratory↗

PubMedDate not supplied

Echocardiographic demonstration of coronary sinus diverticula in patients with Wolff-Parkinson-White syndrome.

Coronary sinus (CS) diverticula have been reported to be the anatomic basis of some posteroseptal accessory atrioventricular pathways. During 1 year, 53 patients with Wolff-Parkinson-White syndrome referred to our center for catheter ablation were found to have posteroseptal or left posterior accessory pathways. The accessory pathway was associated with an anomaly of the CS in seven patients (13%), including six diverticula of the CS or its branches and one aneurysmal CS. Four of the CS diverticula were visualized by transesophageal echocardiography. Diverticular appear as echolucent, contractile pouches on the epicardial surface of the posteroseptal or posterior left ventricle that connect to the CS by an isthmus. Previous reports have suggested that accessory pathways associated with CS aneurysms have rapid conduction times and may be associated with an increased risk of rapid ventricular response during atrial fibrillation and sudden death; five of our seven patients had a short preexcited R-R interval in the range of 172 to 225 msec during atrial fibrillation. In summary, many, if not the majority, of CS diverticula associated with preexcitation can be visualized by transesophageal echocardiography.

Adolescent↗

PubMedDate not supplied

Effect of experimental diabetes mellitus on gentamicin-induced acute renal functional changes in the anaesthetized rat.

1. Rats with streptozotocin (STZ) diabetes are protected from gentamicin (GEN) nephrotoxicity. Because the chronic renal damage from GEN is preceded by acute renal functional changes (notably hypercalciuria), the present study aims to determine whether diabetes may also protect against the acute effects of the drug. If there is a link between the rapid physiological actions of GEN and its subsequent nephrotoxicity, the former may also be affected by the diabetic condition. 2. Standard renal clearance techniques were performed on anaesthetized rats that had been injected with STZ or vehicle 2 weeks previously. All animals were infused with 0.9% NaCl for 5 h and then either GEN (0.28 mg/kg per min) or 0.9% NaCl alone for 2 h. 3. Baseline fractional calcium excretion (FE(Ca)) of diabetic rats was three-fold that of control animals (6.6+/-0.2 vs 2.2+/-0.2%, respectively; P<0.01, MANOVA). Following GEN infusion, a comparable increase in FE(Ca) occurred in control and diabetic rats (5.3+/-0.6 vs 5.3+/-0.8%, respectively; NS). 4. Streptozotocin diabetes, therefore, does not alter the acute hypercalciuric response to GEN. This may suggest that the acute effects of GEN on renal calcium handling do not contribute to the subsequent nephrotoxicity. However, the higher baseline FE(Ca) seen in diabetic rats may afford protection against the renal injury caused by gentamicin.

Anesthesia↗

PubMedDate not supplied

The development of an effective tissue viability service.

Wound management and the prevention and treatment of pressure ulcers is recognized as a major quality issue (Department of Health (DoH), 1993). However, there remains a number of NHS trusts who operate without a formal tissue viability service (TVS) (Dealey, 1994). The aim of this article is to assist those wishing to develop such a service by describing how the authors' TVS became established and how it has developed during the subsequent 5 years (Smith, 1996). It is anticipated that this information will provide a framework for practitioners who want to develop this specialty within their own trust. Traditionally, the detection and treatment of pressure ulcers has been the role of nursing staff. However, it is now recognized that this responsibility lies with many members of the multidisciplinary team, the members of which provide the foundation of an effective TVS (Smith, 1993).

Humans↗

PubMedDate not supplied

Nutritional screening: an audit.

Despite much guidance, patients in hospital are still not eating properly. This article discusses the development of a Nutritional Screening Tool (NST) and an audit of the use of the tool with nutritional supplements.

Humans↗