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Biomedical subjects

G E Allen

Publications and source records attributed to G E Allen.

At least 19 recordsLinked to original sources
PubMed2003

Association between long-term acitretin therapy and osteoporosis: no evidence of increased risk.

Osteoporosis has been observed with chronic hypervitaminosis A, leading some authors to hypothesize that systemic retinoids may have an effect on bone mineral density. Two previous small studies identified osteoporosis in patients who received long-term therapy with etretinate. Etretinate has now been superceeded by acitretin in clinical use. We hypothesized that bone mineral density is lower in patients taking long-term acitretin than control cases who had never taken acitretin. Thirty Caucasian patients receiving acitretin for a median of 3.6 years for a variety of dermatoses were studied. Bone mineral density measurements were determined using DEXA scanning at two standard sites, the lumbar spine and Ward's triangle. We did not find an association between daily dose of acitretin, total dose administered or overall duration of treatment and risk of osteopenia or osteoporosis. Acitretin appears to be safe for long-term use in patients with chronic dermatoses.

Absorptiometry, Photon↗
PubMed2000

The reception of Mendelism in the United States, 1900-1930.

Scholars have differed on the question of why Mendel's work was neglected between 1865 and 1900, and the (by contrast) relatively rapid acceptance of Mendelism in many countries after 1900. This paper focuses on two factors that have not been well explored in the debate. The first is that Mendelism fit perfectly into the atomistic philosophy associated with mechanistic materialism in western science, and thus was strongly promoted by a younger group of biologists around 1900 to raise the prestige of biology to the rigorous level of the physical sciences. The second factor was that Mendelian theory, with its experimental and predictive qualities, fit well into the new demands for industrialization of agriculture both to feed a growing urban population and to provide an arena for capital expansion. This paper proposes that the early promotion of Mendelian research, by both private and public funds, owed as much to economic and social as to biological causes.

Animal Husbandry↗
PubMed1998

Changes in protein kinase C in early cardiomyopathy and in gracilis muscle in the BB/Wor diabetic rat.

Hyperglycemia can upregulate protein kinase C (PKC), which may be an important mediator of the progression from normal heart and muscle function to diabetic myopathy in the myocardium and skeletal muscle in type 1 insulin-dependent diabetes mellitus (IDM). We evaluated this possibility during the early stage of IDM in BB/Wor diabetic (D) rats and age-matched BB/Wor diabetes-resistant (DR) rats. Interventricular septal thickness, E wave peak velocity of tricuspid inflow (both minimum and maximum), and left ventricular (LV) weight index were increased, and the rate of change in LV pressure (LV dP/dt) decreased in D rats subjected to M-mode and two-dimensional echocardiography and hemodynamic recording of heart rate, LV pressure (LVP), + LV dP/dt, -LV dP/dt, and LV end-diastolic pressure (LVEDP) in vivo and in vitro 41 days after the onset of hyperglycemia. Whole ventricle basal PKC activity was increased by 44.4 and 18.4% in the particulate and soluble fractions, respectively, from D rats compared with that from DR rats using r-32P phosphorylation of appropriate peptide substrates. When measured by Western blot gel densitometry, particulate PKC-alpha and PKC-delta content increased by 89 and 24%, respectively, but soluble PKC-beta and soluble and particulate PKC-epsilon were unchanged compared with that of DR rats. Similarly, gracilis muscle PKC activity and PKC-alpha and PKC-delta were elevated in the gracilis muscle, whereas that of the circulating neutrophil did not differ between the D and DR rats. Thus, in vivo, the early diabetic cardiomyopathy of the D rat is characterized by a restrictive LV with increased septal thickness and is associated with elevated PKC activity and increased amounts of myocardial particulate PKC-alpha and PKC-delta, which are also seen in the skeletal muscle. We conclude that increased PKC isozymes may play a pivotal role during IDM in the development of diabetic cardiomyopathy and skeletal muscle myopathy.

Animals↗
PubMed1997

The social and economic origins of genetic determinism: a case history of the American Eugenics Movement, 1900-1940 and its lessons for today.

Eugenics, the attempt to improve the genetic quality of the human species by 'better breeding', developed as a worldwide movement between 1900 and 1940. It was particularly prominent in the United States, Britain and Germany, and in those countries was based on the then-new science of Mendelian genetics. Eugenicists developed research programs to determine the degree in which traits such as Huntington's chorea, blindness, deafness, mental retardation (feeblemindedness), intelligence, alcoholism, schizophrenia, manic depression, rebelliousness, nomadism, prostitution and feeble inhibition were genetically determined. Eugenicists were also active in the political arena, lobbying in the United States for immigration restriction and compulsory sterilization laws for those deemed genetically unfit; in Britain they lobbied for incarceration of genetically unfit and in Germany for sterilization and eventually euthanasia. In all these countries one of the major arguments was that of efficiency: that it was inefficient to allow genetic defects to be multiplied and then have to try and deal with the consequences of state care for the offspring. National socialists called genetically defective individuals 'useless eaters' and argued for sterilization or euthanasia on economic grounds. Similar arguments appeared in the United States and Britain as well. At the present time (1997) much research and publicity is being given to claims about a genetic basis for all the same behaviors (alcoholism, manic depression, etc.), again in an economic context--care for people with such diseases is costing too much. There is an important lesson to learn from the past: genetic arguments are put forward to mask the true--social and economic--causes of human behavioral defects.

Eugenics↗
PubMed1996

Day 4 is better than day 3 for a single patch test reading.

Readings were performed on day (D) 2, D3 and D4 after application of patch tests in 88 patients. 90 patch test reactions in 49 patients were interpreted as allergic and of past or present relevance. A single D2 reading detected 58 of the allergic reactions with 32 false-negatives and 23 false-positives. A single D3 reading detected 77 allergic reactions, with 13 false-negatives and 17 false-positives. A single D4 reading detected 85 allergic reactions, with 5 false-negatives and 9 false-positives. Therefore, if only a single reading is feasible, it is better performed on D4 than on D3.

Allergens↗
PubMed1991

Treatment of chronic varicose ulcers with pulsed electromagnetic fields: a controlled pilot study.

To evaluate the efficacy of pulsed electromagnetic fields (PEMF) in healing of chronic varicose ulcers, 19 patients with this condition were included in a double-blind controlled clinical trial. All patients received standard ulcer therapy throughout the duration of the study and were randomly divided into two groups to receive either active or inactive PEMF therapy. Active therapy was provided by the use of a pait of helmholtz coils on a twice weekly basis over a five week period and inactive therapy was provided on an identical regimen with identical coils wound so that no magnetic field was produced when an electric current was passed through them. The clinician and patients were unable to distinguish the active or inactive coils. No statistically relevant difference was noted between the two groups in the healing rates of the ulcer, change in the lower leg girth, pain or infection rates. However there was a trend in favour of a decrease in ulcer size and lower leg girth in the group treated with active PEMF. As PEMF is a novel treatment for chronic varicose ulcers, more work needs to be done to establish treatment parameters and its usefulness in the treatment of this condition.

Aged↗
PubMed1989

Eugenics and American social history, 1880-1950.

Eugenics, the attempt to improve the human species socially through better breeding was a widespread and popular movement in the United States and Europe between 1910 and 1940. Eugenics was an attempt to use science (the newly discovered Mendelian laws of heredity) to solve social problems (crime, alcoholism, prostitution, rebelliousness), using trained experts. Eugenics gained much support from progressive reform thinkers, who sought to plan social development using expert knowledge in both the social and natural sciences. In eugenics, progressive reformers saw the opportunity to attack social problems efficiently by treating the cause (bad heredity) rather than the effect. Much of the impetus for social and economic reform came from class conflict in the period 1880-1930, resulting from industrialization, unemployment, working conditions, periodic depressions, and unionization. In response, the industrialist class adopted firmer measures of economic control (abandonment of laissez-faire principles), the principles of government regulation (interstate commerce, labor), and the cult of industrial efficiency. Eugenics was only one aspect of progressive reform, but as a scientific claim to explain the cause of social problems, it was a particularly powerful weapon in the arsenal of class conflict at the time.

Attitude to Health↗
PubMed1986

Human serum parvovirus associated vasculitis.

A 48 year old man had a severe symmetrical arthritis of knee and ankle joints accompanied by an extensive purpuric rash of both legs and several areas of skin necrosis. No other system was clinically involved. Human serum parvovirus-specific IgM was present in a blood sample taken 2 weeks after the onset of the clinical illness indicating recent infection with this virus. The patient was treated with complete bed rest, and the application of saline soaks to both legs. He had a recurrence of the rash 5 weeks after onset, but otherwise made a complete recovery. Purpura with skin necrosis has not previously been reported in association with this virus.

Arthritis↗