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Biomedical subjects

C M Taylor

Publications and source records attributed to C M Taylor.

At least 145 records · Page 8Linked to original sources
PubMed1986

Effect of oxygen tension on the quantities of procollagenase-activating angiogenic factor present in the developing kitten retina.

Maintenance of newborn kittens in an oxygen rich atmosphere followed by a recovery period in a normal atmosphere mimicked the effects of the human disease retrolental fibroplasia. The retinas of such kittens contained significantly raised levels of low molecular weight angiogenic material (as measured by procollagenase activation) when compared with those of a control group of kittens.

Angiogenesis Inducing Agents↗
PubMed1985

Partial purification of a 5.7K glycoprotein from bovine vitreous which inhibits both angiogenesis and collagenase activity.

An inhibitor of angiogenic activity similar to that described by Raymond and Jacobson (1) has been partially purified and shown to be a glycoprotein of molecular mass 5,700. This inhibitor gave rise to an avascular zone on the chick vitelline plexus and also negated the action of a low Mr angiogenic factor. When the angiogenic inhibitor was incubated with mammalian collagenase it inhibited the enzyme activity by nearly 70%. The relevance of these findings to the role of collagenase in angiogenesis is discussed.

Angiogenesis Inducing Agents↗
PubMed1985

Growth in the international physician supply. 1950 through 1979.

The recent growth in domestic physician supply prompted an investigation of international trends. Using data from the World Health Organization, it was determined that the number of physicians in the world grew from 4.8 per 10,000 population to 10.1 per 10,000 during the period 1950 through 1979. There was a 96% increase in industrialized nations, 223% in nations with centrally planned economies, 164% in middle-income nations, and 29% in low-income nations. Relationships in growth in physician supply and production of medical graduates are discussed. Implications of the inequities between the various groupings of countries are discussed.

Brazil↗
PubMed1985

The formation of cerebrospinal fluid in two amphibians, Rana catesbeiana and Rana pipiens.

The cerebrospinal fluid (CSF) system of two amphibians, Rana catesbeiana and Rana pipiens has been perfused from the lateral ventricle to a site in the subarachnoid space close to the roof of the fourth ventricle. The CSF production rate (Vf) was measured by the dilution method using a perfusion fluid containing [14C]dextran in artificial CSF. For Rana catesbeiana Vf was 1.43 microliter min-1 or 0.2 microliter min-1 mg choroid plexus-1 and for Rana pipiens Vf was 0.2 microliter min-1 or 0.1 microliter min-1 mg choroid plexus-1. These control values declined by 35% and 14% respectively in the second half of the experimental period. Ouabain (5 X 10(-5) M) in the perfusion fluid for the second half of the experiment resulted in a much greater reduction in Vf, viz. 65% for Rana catesbeiana and 71% for Rana pipiens. Acetazolamide (1 X 10(-4) M) in the perfusion fluid for the second half of the experiment gave no change in Vf values when compared with control 74.5 +/- 4.8 microliters.

Acetazolamide↗
PubMed1985

Assembly of chick and bovine lens-capsule collagen.

Chick-embryo and adult bovine lens-capsular epithelia in organ culture synthesized 4-hydroxy[3H]proline-containing polypeptides when incubated in the presence of [3H]proline. These collagenous polypeptides of apparent Mr 180 000, 175 000 and 160 000 became incorporated with time into aggregates of higher molecular size. The formation of such aggregates was inhibited when the tissues were labelled in the presence of beta-aminopropionitrile, thereby implicating lysine-derived cross-links in aggregate formation. When the tissues were incubated in the presence of tunicamycin, the collagenous polypeptides synthesized exhibited increased electrophoretic mobilities on sodium dodecyl sulphate/polyacrylamide-gel electrophoresis. The addition to lens-capsule incubation medium of alpha alpha'-bipyridine led to the synthesis of underhydroxylated type IV collagen, also of increased electrophoretic mobility. Extended pulse-chase experiments indicated that such underhydroxylated collagen did not participate in aggregate formation, but was at least as stable as fully hydroxylated non-cross-linked collagen synthesized in the presence of beta-aminopropionitrile. Native type IV collagen, recovered from the culture medium when capsules were incubated with [3H]proline for 24h, was purified by ion-exchange chromatography. Separations conducted on CM-cellulose under denaturing and nondenaturing conditions suggested that the alpha 1(IV) and alpha 2(IV) chains occur in the same heterologous triple helix. Densitometric analyses of appropriate fluorograms indicated that these two polypeptides occur in a 2:1 ratio, suggesting that lens-capsule collagen is synthesized as a triple-helical molecule of composition [alpha 1(IV)]2 alpha 2(IV).

2,2'-Dipyridyl↗
PubMed1985

Comparison of differentiation patterns in 12-O-tetradecanoylphorbol-13-acetate-treated epidermis and fetal epidermis.

12-O-Tetradecanoylphorbol-13-acetate (TPA)-treated adult epidermis as well as untreated fetal and adult epidermis were investigated to elucidate the effect of TPA in terms of cell differentiation using techniques of ultrastructural stereology. Twenty-four hours after a single application of TPA, the treated epidermis was characterized by involutional changes, i.e., increased volume density of intercellular spaces and of mitochondria, vacuoles, and cytoplasmic ground substance in the basal layer. However, 48 h after application, the TPA-treated epidermis was very similar to fetal epidermis, i.e., high volume density of nuclei ribosomes, rough endoplasmic reticulum, membrane-coating granules, and keratohyalin granules, and low volume density of bundled filaments in the upper layers. These stereological data indicate that the changes observed 48 h after TPA treatment were related not only to increased cell proliferation but also to inhibition of cell differentiation expressed as a reversion of the adult differentiation patterns and the acquisition of fetal characteristics in all epidermal layers.

Animals↗
PubMed1985

Rating scales for depression and anxiety: a current perspective.

Research now requires instruments capable of a better distinction between depressive and anxiety disorders. The study is concerned with two relatively recent clinician-rated scales, the Montgomery-Asberg Depression Rating Scale and the Clinical Anxiety Scale together with two recent self-assessment scales, the Irritability-Depression-Anxiety Scale and the Hospital Anxiety and Depression Scale. The concurrent validity of these scales as measures of the separate concepts of anxiety and depression is examined.

Anxiety↗
PubMed1985

Irritability: definition, assessment and associated factors.

The heading of 'Irritable Mood' was introduced into the Index Medicus in 1985 and it is noted that this term is frequently used but seldom defined. It is therefore important that a consensus is reached concerning its definition in the context of psychopathology and a definition is offered. It seems important to distinguish irritable mood and its outward manifestations from violently assaultive behaviour although there may be a continuum of disturbance from mildly to severely disordered behaviour. Irritability has so far not attracted much attention from clinicians and yet it is a common mood associated with many psychiatric and non-psychiatric conditions. Severe irritability may cause considerable distress both to the patient, his associates and sometimes also those attempting to treat or otherwise help him. It may overshadow other symptoms and the correct diagnosis and management may be missed. The validity and reliability of a convenient self-assessment scale is re-examined in the light of further data. Data from previous studies in the context of mood disorders suggests that irritability is a mood state which is independent of the other major moods of depression and anxiety; the severity of irritability probably has an inverse correlation with age. The most important associated factors are listed in order to inform researchers of the possible methodological pitfalls.

Adult↗
PubMed1984

A simple method to determine whole cell uptake of radiolabelled oestrogen and progesterone and their subcellular localization in breast cancer cell lines in monolayer culture.

Specific uptake of tritiated 17 beta-oestradiol and R5020, a synthetic progestin, in breast cancer cell lines ( MCF7 and T47D) growing in monolayer culture in multiwell plates has been shown. Binding characteristics, calculated by Scatchard analysis, indicate the presence of steroid receptors of similar affinities and capacities to those already obtained with broken cell preparations. Lysis of the cells by treatment with a hypotonic buffer reveals the subcellular localization of the receptors so the method can be used to study receptor dynamics such as nuclear translocation and processing. Cell growth can be measured by DNA determination directly in the multiwell plates. Thus, the method provides a convenient way of studying the effects of steroid hormones (or any antihormone or chemotherapeutic agent) on growth and receptor content of breast cancer cells in monolayer culture.

Breast Neoplasms↗
PubMed1984

Australia's environment and its influences on health.

While the Australian geographic environment is essentially benign, we have had a history of imported infectious diseases which requires continual surveillance to avoid recurring in this age of high international mobility. Urbanisation and an ageing population provide what is now a common picture of health care problems found in most Western societies. There is renewed emphasis on environmental health policy making and the development of stronger strategies of health conservation in the workplace. Many of these efforts have to cope with the difficult legislative arrangements relating to Federal and State jurisdictions.

Australia↗
PubMed1984

Absorption of the cerebrospinal fluid and intracranial compliance in an amphibian, Rana pipiens.

Experiments have been carried out to investigate the absorption of the cerebrospinal fluid (c.s.f.) and the intracranial compliance in an amphibian, Rana pipiens, using infusions into the c.s.f. system through glass micropipettes. Resistance to absorption of the c.s.f. was estimated by the constant rate infusion technique. Mean absorption resistance for infusions of artificial c.s.f. into the lateral ventricles and into the cerebral subarachnoid space were 15.48 and 16.52 mmH2O min microliter-1 respectively. This difference was not significant and it is concluded that the pores in the posterior tela situated in the roof of the fourth ventricle do not offer any resistance to the flow of c.s.f. out of the ventricles. The resistance to drainage of the c.s.f. in this amphibian is higher than that found for mammals. Mean resting c.s.f. pressure, estimated from the intercept of the regression line with the pressure axis at zero infusion rate was 18.0 mmH2O. Absorption resistance was measured from the cerebral subarachnoid space before and after injection of 4 microliter Indian ink solution. There was a 3-fold increase in resistance following ink injection. Two-way analysis of variance showed the difference to be significant (P less than 0.01) suggesting that the outflow sites can become partially blocked by particulate matter. During a continuous 3 h infusion of artificial c.s.f. containing [14C]dextran or [125I]-labelled human serum albumin (RISA) into the lateral ventricles, the mean percentage uptakes into the systemic circulation after the first 0.5 h of a 3 h period were 74.1 and 61.9% respectively. The difference is not significant. The rapid and high uptake into blood suggests there is a direct communication between c.s.f. and blood in amphibians. During continuous infusion of RISA into the lateral ventricles, simultaneous blood samples were taken from the femoral artery and the internal dorsal vertebral vein. Radioactivity was found to be 13.2% higher in venous samples. This suggests that at least some c.s.f. drainage takes place directly into the spinal venous system. Intracranial compliance was investigated by recording the peak pressure in response to a series of bolus injections of artificial c.s.f. into one lateral ventricle. Compliance was estimated to be 0.11, 0.10 and 0.09 microliter mmH2O-1 for injection rates of 12.74, 16.62 and 25.10 microliters min-1 respectively. The difference between these values is not significant. The results suggest that for injection volumes over 5 microliters the c.s.f. system behaves elastically.

Absorption↗
PubMed1984

Vitamin E treatment of haemolytic uraemic syndrome.

Because low plasma vitamin E concentrations have been reported in patients with haemolytic uraemic syndrome and there is accumulating evidence of lipid peroxidation in this disease, treatment with the antioxidant vitamin E was undertaken in 16 consecutive children with the syndrome. Twelve children had features at presentation suggesting a poor prognosis for recovery but despite this all 16 patients survived and are well three months later. Fifteen children now have normal values for serum creatinine, blood pressure, and urinalysis for protein but one has slight renal impairment. Although this is not a report of a controlled trial, it seems that patients treated with vitamin E have fared considerably better than our previously treated patients with haemolytic uraemic syndrome, even in the presence of early, adverse prognostic features. We suggest that vitamin E alters the natural history of the disease, and in view of the absence of any observed side effects further experience with this treatment is being sought.

Child↗
PubMed1984

Calcium restriction and parathyroid hormone enhance renal compensatory growth.

Calcium has been shown to control the proliferation of various cells in vitro and in vivo. Despite this information it is not known whether the Ca status or Ca-regulating hormones could modulate the degree of compensatory growth of the remaining kidney after renal mass reduction. In the present work the influence of dietary Ca, parathyroid hormone (PTH), and calcitonin (CT) on renal compensatory growth ( RCG ) was studied in unilaterally nephrectomized (UNI-NX) rats. UNI-NX rats were pair-fed diets with high (1.1%, HCa) or low (0.1% LCa) Ca content for 3, 8, and 15 days. After UNI-NX the wet weight of the remaining kidney increased much more in rats fed LCa than HCa. Values of dry weight, total protein, and DNA content were also significantly higher in the remaining kidney removed from rats fed LCa than from those fed HCa. LCa did not display such effects in sham-operated rats with intact renal mass. The amount of dietary Ca did not influence the progressive rise in glomerular filtration rate (clearance of inulin) of the remaining kidney as assessed 3, 8, and 15 days after UNI-NX. In UNI-NX rats fed LCa chronic administration of CT in doses that induced hypocalcemia did not inhibit the enhanced RCG induced by LCa. In UNI-NX rats fed HCa chronic administration of PTH mimicked the effect of LCa. In conclusion, dietary Ca restriction can markedly enhance the compensatory but not the normal growth of the kidney.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗