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Biomedical subjects

M Nowak

Publications and source records attributed to M Nowak.

At least 163 records · Page 9Linked to original sources
PubMed1987

Adrenocortical function in 4-APP treated rats: a coupled stereological and biochemical study.

Adrenocortical function in 4-APP-induced (4-aminopyrazolo[3,4-d]pyrymidine) lipoprotein-deficient rats was studied in relation to quantitative morphologic changes in the gland. 4-APP treatment results in enlargement of the adrenal cortex and its zona fasciculata and reticularis cells. In enlarged livers, cholesterol and free fatty acid concentrations were similar to that of control rats, however a marked accumulation of triglycerides with a concomitant drop in hepatic delta 4-steroid hydrogenase activity was found. A profound drop in serum cholesterol in both, high and low density lipoproteins, as well as triglycerides and plasma corticosterone concentrations was accompanied by a marked lowering of cholesterol and corticosterone concentration in the adrenal gland. Corticosterone output by adrenal homogenates was higher in 4-APP treated rats than in control animals. Such a treatment did not change cholesterol side-chain cleavage, 11 beta-hydroxylase, 3 beta-ol dehydrogenase-isomerase, steroid 5 alpha-reductase and neutral lipase activities when expressing results per unit weight of tissue or protein. However, when calculating per adrenocortical cell, adenine analogue applied increased 11 beta-hydroxylase, steroid 5 alpha-reductase and neutral lipase activities. Thus, coupled biochemical and stereologic studies revealed a complex and multidirectional effect of 4-APP on the rat adrenal cortex. This effect may be caused by serum lipoprotein deficiency and by toxic and stressful action of the adenine analogue on the rat. Also a direct effect of 4-APP on rat adrenal cortex may not be excluded.

Adenine↗
PubMed1987

Stereologic studies on the adrenal cortex of 4-APP (4-amino-pyrazolopyrimidine)-induced lipoprotein-deficient rats.

The effect of 4-APP (4-aminopyrazolopyrimidine), the compound reducing hepatic release of lipoproteins, on the rat adrenal cortex was studied by means of stereological methods. Within 3 days 4-APP resulted in a marked increase in the absolute and relative adrenal weights and markedly lowered plasma and adrenal total cholesterol concentration. 4-APP did not change the relative volume of individual adrenocortical zones, however significantly increased the volume in mm3 of the zona fasciculata (ZF) and reticularis (ZR) and of the entire cortex. The average volume of the ZF and ZR cells of 4-APP treated rats was markedly higher than in control rats while no difference was found in the zona glomerulosa (ZG) cell. In lipoprotein-deficient rats the number of adrenocortical cells within the entire cortex was similar to that observed in control rats. A marked increase in the number of mitoses in both, adrenocortical and endothelial cells suggests inhibitory action of 4-APP on the proliferative activity of these cells. The present study shows that 4-APP-induced changes in the rat adrenal cortex mainly depends upon the stimulatory action of that compound on ACTH secretion, however this adenine analogue also exerts a direct action on the adrenocortical cells.

Adenine↗
PubMed1987

Collagen peptidase in serum of patients with myocardial infarction.

Activity of collagen peptidase was measured in patients with myocardial infarction. Determinations were carried out 1, 3, 6, 9, 14 and 21 days after admission to the hospital. A decrease of activity was observed between the 6th-21st day of the disease. A low correlation with serum aminotransferases was found. It is concluded that estimation of serum collagen peptidase does not reflect accumulation of collagen in the healing heart muscle.

Adult↗
PubMed1987

In vitro drug screening in isolated male Onchocerca gibsoni using motility suppression.

A primary in vitro screen was developed to screen for drug activity against isolated Onchocerca gibsoni. The assay estimates variation in motility through the use of a motility meter. Of the seven compounds tested in the screen; ivermectin, CGP 6140, CGP20376, Mel W and furapyrimidone gave MI50 concentrations (the concentration at which the motility was reduced to 50% of the control value at 72 hours) below 10(-4) M, whereas suramin gave variable results depending on the varying susceptibility of individual worms and levamisole at 10(-4) M had no significant effect on the worms. The effects of these drugs were not reversible as removal of the worms into drug-free medium caused no increase in motility. Thus the reduction in motility is regarded as indicating significant metabolic damage. The results compared favourably with reported in vivo tertiary screens for activity against Onchocerca species. This is a quantitative, inexpensive and reproducible method for assessing the effectiveness of drugs against Onchocerca and could be included into the primary screens for activity against filarial worms.

Animals↗
PubMed1985

Estradiol and melatonin effects on adrenal cortex of ovariectomized and pinealectomized rats.

Studies on the effect of pinealectomy (PX) and melatonin on adrenal cortex of ovariectomized and estradiol replaced rats were performed. Neither PX nor melatonin replacement changed corticosterone output by adrenal homogenate, 11 beta-hydroxylase activity, liver corticosterone metabolism or serum corticosterone level, however, melatonin increased adrenal 5 alpha-reductase activity. On the other hand, PX of 14 months duration resulted in an increase in intraadrenal 5 alpha-reductase activity. PX did not modify estradiol effect on rat adrenal cortex, while concomitant estradiol-melatonin administration increased corticosterone output by adrenal homogenate. Stimulatory effect of estradiol on liver corticosterone metabolism was observed only in the presence of pineal gland or exogenous melatonin. In non of experiments, 45 nmole/ml of melatonin added into incubation medium stimulated adrenal 5 alpha-reductase activity. Obtained results cast doubt on a physiological role of melatonin in regulation of adrenocortical secretory activity in ovariectomized rats and suggest that estradiol effect on the adrenal cortex is not mediated by the pineal gland.

Adrenal Cortex↗
PubMed1985

The health workforce. Some structural features illustrated.

A combination of structural features on both the supply and demand side make the labour market for certain health professionals relatively unique. These features are outlined and the occupations identified. The adjustment mechanism in the market for these occupations is considered to be highly responsive to these features; a simple model is outlined. Finally the model is brought to bear on the possible responses to two aspects of the WA market, firstly the perceived 'shortage' of registered nurses and secondly the longer term relationship of supply and demand in an industry with rapidly growing labour supply.

Allied Health Personnel↗
PubMed1984

Cancer of lymphatic tissues in cane-growing areas of Queensland.

The mortality from leukaemias and lymphomas in a tropical urban region of Queensland (Townsville) and in the mainly tropical cane-farming regions of Queensland was investigated. It was found that, compared with the general population of Queensland, there were fewer deaths from neoplastic disease of the lymphatic tissues in women in both regions; that there were fewer deaths from neoplastic disease of the lymphatic tissues in men in Townsville, but not in the cane-growing areas; and that, during the period 1968-1981, there was a significantly lower number of deaths from leukaemia (13 deaths; SMR, 49; P less than 0.01) in women over 60 years of age in the cane-growing areas, which contrasted with a significantly greater number of deaths from leukaemia (61 deaths; SMR, 154; P less than 0.01) in men 60 years and over in the cane-growing areas.

Adolescent↗
PubMed1984

Immunosuppression by human skin cancers.

Biopsy samples from normal skin (12 samples) and skin lesions diagnosed as either basal cell (17 cases) or squamous cell carcinoma (5 cases) were frozen, disrupted and extracted with aqueous buffer. The sterilised extract was added to an in vitro system of cultured bovine lymphocytes. The response of the lymphocytes to PHA was measured by tritiated thymidine uptake. Extracts of both basal cell and squamous cell cancers inhibited normal PHA stimulation of lymphocyte mitogenesis. Blastogenesis was reduced by more than 50% by all of the cancer extracts tested. In contrast, similar extracts from normal skin showed less than 40% inhibition.

Animals↗
PubMed1984

Effect of cell-substrate interaction time and shearing force on adhesion of L1210 cells to collagen and glass.

The early adhesive interaction of living cells with substrates was examined. L1210 cells were allowed to interact with collagen or glass in serum-containing medium (time of cell-substrate interaction, tint, under stationary conditions, was within 2-25 min) or in serum-free medium (tint was 5 s-15 min). The relative number A of cells adhering under stationary conditions, and remaining adherent to the substrate despite experiencing a shearing force F, was determined. The following was found for cells adherent to collagen and glass, both in the presence and absence of serum in the medium. The number A increases with the value of tint and tends to reach a plateau. The plateau value depends on adhesion conditions (presence or absence of serum). When adhesion occurred in serum-containing medium (F congruent to 0.1 X 10(-13)N), function A(tint) increased up to 15 min. The plateau values were in the ratio of 2:1 for cells adherent to collagen and glass, respectively. When adhesion took place in serum-free medium, the function A(tint) increased within the first 20 or 130s for cells adhering to glass or collagen, respectively. The value of A(tint) increased up to the effective interaction time, teff int, i.e. the time after which a plateau was reached at 100% adhesion. This meant that after tint greater than or equal to teff int all cells were in adhesion with glass and collagen despite the application of the greatest shearing force, F congruent to 2 X 10(-9)N. The values of teff int for cells adherent to collagen and glass were in the ratio of 6:1, respectively. The value of A decreases with the value of F for cells adherent to substrate in the absence of serum when tint less than teff int. The function A(F) for cells adherent to collagen and glass in the presence of serum, but not in the absence of serum, can be described by the equation: A = a/square root F + c, where a and c = constant greater than 0. The values of a were in the ratio of 2:1 for cells adherent to collagen and glass, respectively. The Brownian motion of cells interacting with both substrates in the absence of serum ceased. The times during which cell motion persisted for cells interacting with collagen and glass, respectively, were in the ratio of 2.5:1.

Animals↗
PubMed1983

Therapeutic and clinical course of deep vein thrombosis.

We have reviewed our experience with the treatment of 250 patients with deep vein thrombosis diagnosed by contrast venography. The level of thrombosis was recorded according to the anatomic level to which it extended. A third of the patients had cancer, and the most common clinical findings were swelling and pain. The risk of the development of pulmonary embolism, based on the anatomic level of initial deep vein thrombosis, revealed the following: 12 of 115 patients (10 percent) with level I (calf) deep vein thrombosis developed pulmonary embolism, as did 2 of 27 patients (7 percent) with level II (popliteal) disease, 5 of 60 (8 percent) with level III (thigh) disease, 1 of 19 patients (5 percent) with level IV (groin) disease, and 2 of 26 patients (8 percent) with level V (iliac) disease. Based on our favorable experience with heparin we believe that heparin is the treatment of choice for deep vein thrombosis regardless of the anatomic level. The incidence of pulmonary embolism does not appear to be influenced significantly by the level of the deep vein thrombosis.

Adolescent↗
PubMed1983

The effects of arsenic compounds on human and bovine lymphocyte mitogenesis in vitro.

The response of human and bovine peripheral blood lymphocytes to PHA stimulation was measured in the presence of low concentrations of sodium arsenite and sodium arsenate. In bovine lymphocytes, 41% augmentation of the response occurred at 10(-6) M arsenite with a return to the normal response at 2.5 X 10(-6) M. Complete inhibition of mitogenesis occurred at 6 X 10(-6) M. In the presence of sodium arsenate, similar results were obtained but at the higher concentrations of 2 X 10(-5) (for 57% augmentation), 5.2 X 10(-5), and 1.9 X 10(-4) M, respectively. The possible significance of these findings in view of the known relationship between chronic arsenicalism and human skin cancer is discussed. It is suggested that arsenic compounds may, by potentiating mitogenesis, increase the possibility of errors in DNA replication, some of which could be potentially carcinogenic. Additionally, interference with the immune response could enable potentially cancerous cells to escape immune surveillance.

Animals↗