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Biomedical subjects

F Anderson

Publications and source records attributed to F Anderson.

At least 37 records · Page 2Linked to original sources
PubMed1992

Monitoring hemangioblastoma tumor burden using plasma erythropoietin levels.

We report a 39-year-old female patient with a hepatic hemangioblastoma, polycythemia and elevated plasma erythropoietin (Epo) levels. Following orthotopic liver transplantation (OLTx), her plasma Epo levels and hematocrit normalized but began to rise several months later. This rise correlated with the appearance of multiple lung metastases. The tumor was implicated as the source of excess Epo production using Northern analysis of a resected metastatic lung nodule. Based on our results, the measurement of plasma Epo levels in patients with Epo secreting tumors could be of general utility in assessing tumor burden.

Adult↗
PubMed1991

Isolation of avian osteoclasts: improved techniques to preferentially purify viable cells.

Among the many different methods that have been used to obtain and study isolated osteoclasts from a variety of species, the egg-laying hen maintained on a low-calcium diet has proven to be one of the richest sources of relatively large numbers of osteoclasts. However, recent reports and our own observations indicate that only a very small proportion of the osteoclasts harvested by such methods are viable. The difficulty in obtaining large numbers of viable osteoclasts has restricted studies of osteoclast function and regulation, and so new isolation methods were sought. This report describes an osteoclast isolation procedure designed to substantially enrich for large numbers of viable authentic osteoclasts. Size and cell density differences between osteoclasts and contaminating mononuclear cells have been exploited in developing the methods for osteoclast enrichment. Sequential nonenzymatic and enzymatic procedures, followed by cell density separations, have yielded three populations of osteoclasts derived from chick hatchlings maintained on a low-calcium diet. A corresponding decrease in bone-associated osteoclasts during the sequential isolation scheme has been monitored using an osteoclast-directed monoclonal antibody, 121F. The first two populations contain 40% osteoclasts, which are predominantly (greater than 99%) nonviable, but the third population contains 8-fold more viable osteoclasts, effectively increasing the proportion of viable osteoclasts more than 25-fold in comparison with the first two populations. The osteoclast-like nature of the isolated viable population 3 cells was established by demonstrating ruffled border formation, possession of the 121F monoclonal antibody-reactive osteoclast antigen, bone particle resorption activity, and resorption pit formation on cortical bone slices revealed by transmission and scanning electron microscopy.

Animals↗
PubMed1991

Gonadotropin-releasing hormone agonist-induced ovarian hyperstimulation: low-dose side effects in women and monkeys.

OBJECTIVE: To determine whether low (subtherapeutic) doses of gonadotropin-releasing hormone agonists (GnRH-a) can cause ovarian hyperstimulation. DESIGN: The study is in two parts: a preliminary clinical trial of women and a follow-up study in laboratory primates. SETTING: Normal human volunteers were studied in an academic research environment; primates were in a conventional laboratory setting. PATIENTS, PARTICIPANTS: Human volunteers were selected on the basis of apparent normal health. The monkeys were believed to be of normal reproductive status. INTERVENTIONS: Gonadotropin-releasing hormone agonists were administered at subtherapeutic doses. MAIN OUTCOME MEASURES: After observing ovarian hyperstimulation in two of five women receiving low doses of GnRH-a, a study was specifically designed to test the hypothesis that at low (subtherapeutic) doses of GnRH-a the "flare-effect" can be sustained without achieving down regulation. RESULTS: The data in women and monkeys suggest that a highly individualized response to low GnRH-a doses can be manifested as ovarian hyperstimulation. CONCLUSION: Four points of interpretation are offered: (1) that subtherapeutic doses of GnRH-a can cause ovarian hyperstimulation and related sequelae; (2) this may be a unique observation in that, typically, lower doses of medications have a lower incidence of negative side effects; (3) the findings suggest that GnRH-a prescribed in self-administration regimens may be more prone to such problems in noncompliant patients; and (4) the hyperstimulation response of the ovaries to low GnRH-a doses may indicate a new approach to controlled ovulation induction, although wide individualism was found.

Administration, Intranasal↗
PubMed1988

Normal splenic function in children with the nephrotic syndrome.

Children with the idiopathic nephrotic syndrome (NS) are known to be susceptible to bacterial infections. A recent report suggested that splenic hypofunction may be responsible for this immunological defect. We assessed splenic function by counting the circulating pocked red blood cells (PkRBCs) using interference phase contrast microscopy. PkRBCs are removed by the spleen, so that normal eusplenic individuals have less than 2% PkRBCs while asplenics have 15%-30%. Intermediate values are seen in hyposplenism. Thirty-three measurements of PkRBCs were made in 19 children with NS (mean age 7.5 +/- 0.8 years). PkRBCs were normal in all children tested (range 0-0.8%), including two patients with bacterial peritonitis associated with relapse. Thus we were unable to find evidence of hyposplenism in children with NS.

Adolescent↗
PubMed1987

Descriptive epidemiology of bronchial reactivity in an adult population: results from a community study.

The bronchial response to inhaled histamine has been suggested as an epidemiological tool for assessing the prevalence of asthma, though the exact relationship between reactivity and asthma is unknown. Tests of bronchial reactivity to histamine were carried out in 511 subjects aged 18-64 years, randomly selected from the population in two areas of the South of England, who had returned questionnaires on respiratory symptoms. Bronchial reactivity to less than or equal to 8 mumol histamine was present in 14% and was associated with positive skin test responses to common allergens and with smoking history. Both of these relationships were in turn dependent on age, skin sensitivity being the more important determinant of reactivity in the young and smoking the more important in older subjects. Bronchial reactivity was least prevalent in the 35-44 year age group. No independent effect on reactivity of sex, social class, or area of residence was detected, and no significant effect from recent respiratory tract infections. Interpretation of the bronchial response to histamine in selected groups of subjects must take account of age, atopic state, and smoking history.

Adult↗
PubMed1987

Education in geriatric medicine.

Geriatric medicine, the branch of general medicine concerned with the clinical, preventive, remedial and social aspects of illness in the elderly and with the maintenance of their health became of importance with the advent of the British National Health Service which uncovered an immense amount of illness among older people. This and the future demographic changes prompted the teaching of medical students gerontology i.e., the study of the ageing process and geriatric medicine. Attempts at preventing illness and at diagnosing disease early were made to try to maintain and, where possible, to improve the health of older people by such methods as motivation, pre-retirement training and early ascertainment of illness. Symptoms of disease change with advancing age and diagnosis becomes difficult due to atypical and insidious symptomatology while the common occurrence of multiple pathology can unfortunately encourage polypharmacy. Specialised instruction in geriatric medicine is thus desirable and the recommendation is made that every medical school should create an academic unit in this subject to provide undergraduate and postgraduate teaching about the process of ageing and the clinical problems of older people with additional instruction on the general management of the elderly both in their own homes and in the essential and varied institutional settings. As well as medical students many other groups such as nurses, paramedicals, social workers and all those who care for the elderly benefit from training.

Curriculum↗
PubMed1984

Persisting vitamin D deficiency in the Asian adolescent.

A study of 221 children admitted to hospital in the course of a year allowed establishment of a reference range for plasma 25-hydroxyvitamin D. None of these children had evidence of biochemical rickets. Most Asian children, however, were vitamin D deficient in comparison, and this deficiency was most noticeable in girls aged 13 to 15 years: biochemical rickets occurred in six per cent of these adolescent Asians. If vitamin D requirements are not met during the physiological growth spurt, permanent pelvic deformity may result. Vitamin D deficiency persisting into pregnancy will adversely affect the infant, producing an increased risk of hypocalcaemic fits, dental enamel hypoplasia, infantile rickets, and reduced postnatal growth. Our data support the need for vitamin D supplementation, and we suggest that annual oral vitamin D supplements in the autumn would alleviate the problem.

Adolescent↗