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Biomedical subjects

M Chambers

Publications and source records attributed to M Chambers.

9 recordsLinked to original sources
PubMed1992

Gross and microscopic anatomy of the vagal innervation of the rat heart.

Intrinsic cardiac ganglia and their vagal innervation are described from gross and microscopic dissections and functional studies in the anesthetized, open-chest, adult rat. Dissecting microscope sketches of the ventral and dorsal aspects of the rat heart provide gross descriptions of the anatomical course of the vagal cardiac nerves. Histological sectioning of adipose tissue packets surrounding the terminal endings of vagal branches distributed to the roots of the great cardiac vessels (aorta, pulmonary artery, precaval veins) revealed clusters of autonomic ganglia. These packets or "fat pads" were located: (1) along the dorsal surface of the right precava and extending medially toward the aortic root, (2) deep to the aortic arch, (3) in the angle between the root of the left precava and the pulmonary artery on the superior-dorsal surface of the left atrium, and (4) in the rostro-dorsal interatrial septum. Vagal distributions of small terminal branches were traced to each of these pads, which contained numerous autonomic ganglia. Electrical excitation of right or left cervical vagus elicited varying degrees of sinus slowing, slowing of A-V conduction, and suppression in atrial contractile force. Very small quantities (0.5 mg in 10 microliters saline) of the ganglionic blocking agent, hexamethonium (C6) were injected selectively into a single fat pad, followed by repetition of right or left vagal stimulation, with careful analysis of changes in heart rate (paced and unpaced), A-V conduction, and contractile force.

Adipose Tissue↗
PubMed1992

Evaluation of tools to assess clinical competence.

Assessment of student nurses' clinical skills is an important issue in nurse education. However suitable instruments are difficult to locate, and also to design. In the course of this article the need for scientifically designed and tested assessment instruments is discussed. The thoroughness with which 11 clinical assessment documents were developed was evaluated using specific criteria. It was found that in the majority of cases use of a systematic research process to guide development was not evident. However it must be noted that the assessment documents were only evaluated via their presentation in journal articles. Full details of the entire project had perhaps not been published. The implications of the results, some of the difficulties inherent in instrument design and the limitations of this small review are considered.

Clinical Competence↗
PubMed1991

Effect of contact on nursing students' attitudes to patients.

Shortly before and shortly after they went on district nurse and mental handicap placements the attitudes of university nursing students to elderly people, people who are disabled and people with a mental handicap were assessed. Before the placements the students had a more favourable attitude towards elderly people and towards those who are disabled than towards those with a mental handicap. After the placements their attitudes towards those with a disability had improved. These findings are discussed with reference to the character of the placements.

Adult↗
PubMed1991

Endopyelotomy: review of results and complications.

Percutaneous endopyelotomy augmented by balloon dilation was performed on 27 of 40 patients for the treatment of symptomatic, primary ureteropelvic junction obstruction. Percutaneous ultrasonic lithotripsy was performed simultaneously on 12 of 27 patients (44%) for associated calculi. After endopyelotomy 24 of 27 patients became asymptomatic (clinical success rate 89%). Three clinically improved patients demonstrated only radiographic stability, while radiographic improvement was documented in 21 of 27 (radiographic success rate 78%). Adjuvant percutaneous ultrasonic lithotripsy was successful from the standpoint of stone removal in all patients and no increased morbidity could be identified. Of 27 patients 3 (11%) suffered major complications and are considered failures. Reasons for failure varied and are discussed. Included is a patient who at nephrostography and stent capping became septic and subsequently died. To decrease the risk of sepsis perioperative antibiotics to include at the time of nephrostomy tube capping are recommended. Angiography was performed in 19 of 40 patients to rule out an accessory crossing vessel at the ureteropelvic junction, and such a vessel was found in 6. From analysis of presenting excretory urograms (IVPs) we conclude that a crossing vessel cannot predictably be identified on an IVP.

Catheterization↗
PubMed1990

Measuring readmission rates.

OBJECTIVE: To assess the feasibility of extracting data on readmissions and readmission rates from Körner data for use as health service indicators. DESIGN: Retrospective analysis of inpatient Körner data for January 1988 to April 1989. SETTING: Three districts in North East Thames region. MAIN OUTCOME MEASURES: Number of readmissions after index discharge for all acute specialties combined and by specialty (general medicine, general surgery, gynaecology, trauma and orthopaedics, and geriatrics); readmission rates at 28 days after index discharge; and rates standardised for age group and sex by specialty and by consultant. RESULTS: All specialties showed an early peak in number of admissions, which levelled off by 28 days. Readmission rates at 28 days were appreciably lower in surgical specialties than in medical specialties (for example, general surgery 4.1% v geriatric medicine 15.1%). They were related to age and sex of the patient. Rates standardised for these variables did not significantly differ by district. Likewise, significant differences in standardised rates were not obtained for consultants within a specialty in one district. CONCLUSIONS: Readmission rates may be measured with Körner data. The pattern of readmissions with time means that readmission rates should be measured at not more than 28 days after the index discharge; the rates require standardisation for age and sex. Annual comparisons of standardised rates may be made among districts for combinations of specialties; those among individual consultants or specialties are unlikely to be statistically valid.

Adolescent↗
PubMed1979

Elastin and granulation tissue.

The contraction of granulation tissue is an important factor in wound healing. The tract of an abdominal drainage tube closes at the rate of 1 mm/h once the tube is removed. Specialized myofibroblasts are generally believed to be responsible for this process and the presence of elastin in granulation tissue has been debated for many years. A 3-mm polyethylene tube was inserted through the left lobe of the liver in 41 rats. A tube of granulation tissue formed around the plastic. This granulation tissue was isolated, after periods ranging from 8 to 20 days, by removing the left lobe of the liver and scraping away the surrounding liver tissue. Biochemical assay for elastin revealed that normal hepatic tissue does not contain any detectable amount of elastin. All 41 samples of granulation tissue contained elastin with a mean value of 8.5 X 10(-6) g of elastin per milligram of tissue. Normal rat aorta contains 31.4 X 10(-6) g of elastin per milligram of tissue. These tubes of granulation tissue were histologically normal and the presence of elastin was recognized using elastin stains. The exact role of elastin in granulation tissue is uncertain but this experiment clearly demonstrates its generation and presence there.

Animals↗
PubMed1978

Role of pituitary hormones in the growth of human breast cancer.

Hypophysectomy was performed in 28 women with Stage IV breast cancer who were treated initially with antiestrogens. Six of 13 patients who responded to tamoxifen and 2 of 12 who failed to benefit from tamoxifen obtained remissions from hypophysectomy. The remissions average 11+ months. Three of 8 patients treated initially with antiestrogens have responded to androgen therapy. The results suggest that hormones other than estrogen, which appears to play a major role, may be involved in stimulating the growth of some human breast cancers. Prolactin receptors were detectable in 51% of human breast cancers and were detected in both estrogen receptor-positive and -negative tumors. Preliminary clinical correlations suggest that prolactin receptors will not be useful in predicting response to antiestrogen therapy.

Breast Neoplasms↗