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Biomedical subjects

J Sokolowski

Publications and source records attributed to J Sokolowski.

At least 19 recordsLinked to original sources
PubMed1995

Inhibition of poly(ADP-ribose) polymerase preserves surfactant synthesis after hydrogen peroxide exposure.

Exposure to hydrogen peroxide (H2O2) decreases phosphatidylcholine (PC) synthesis in rabbit type II pneumocytes. Activation of poly(ADP-ribose) polymerase (PARP) may play a role in this process. Exposure of type II pneumocytes to H2O2 resulted in a 53% decrease in the rate of incorporation of [3H]choline into PC (P < 0.001). Cell NAD and ATP levels were decreased by 52% (P < 0.001) and 39% (P < 0.01), respectively, without significant changes in cell viability. Exposure to H2O2 also resulted in a 52% (P < 0.05) increase in the activity of PARP. Preincubation of type II cells with inhibitors of PARP (nicotinamide; 3-aminobenzamide) before H2O2 exposure prevented the increase in PARP activity, and blocked the decreases in ATP, NAD, and rate of PC synthesis. These results suggest that the energy depletion associated with activation of PARP contributes to the effects of oxidant stress on type II cell metabolic function and may be ameliorated by pharmacological agents in vitro.

Adenosine Triphosphate↗
PubMed1992

Phospholipases introduced into the hypophase affect the surfactant film outlining a bubble.

The hypophase exchanger is a recently developed device that makes it possible to replace the liquid in the sample chamber of a pulsating bubble surfactometer, after a bubble has been formed, without changing the size of the bubble. A surfactant film outlining the bubble will retain its surface properties, provided the liquid entering the sample chamber and replacing the hypophase is inert. If, on the other hand, the new hypophase consists of a phospholipase solution, the physical properties of the film are seriously affected. It was found that when phospholipase C, even at low concentration, entered the sample chamber, the physical properties were significantly changed. Phospholipase A2 had to be added at a higher concentration to exert a similar effect. It is postulated that the site of action of phospholipase A2 may be partly protected in the hydrophobic region of the tightly packed surfactant film.

Animals↗
PubMed1991

Inhibition of pulmonary surfactant function by phospholipases.

Previous studies have shown that respiratory failure associated with disorders such as acute pancreatitis correlates well with increased levels of phospholipase A2 (PLA2) in lung lavages and that intratracheal administration of PLA2 generates an acute lung injury. In addition, bacteria such as Pseudomonas have been shown to secrete phospholipase C (PLC). We studied the effects of these phospholipases on pulmonary surfactant activity using a pulsating bubble surfactometer. Concentrations greater than or equal to 0.1 unit/ml PLA2 destroyed surfactant biophysical activity, increasing surface tension at minimum bubble size from less than 1 to 15 mN/m. This surfactant inactivation was predominantly related to the effect of lysophosphatidylcholine on the surface film, although the fatty acids released with higher PLA2 concentrations also had a detrimental effect on surfactant function. Similarly, as little as 0.1 unit PLC increased the surface tension at minimal size of an oscillating bubble from less than 1 to 15 mN/m, an effect that could be mimicked by the addition of dipalmitin to surfactant in the absence of PLC. Moreover, lower, noninhibitory concentrations (0.01 unit/ml) of PLA2 and PLC increased the sensitivity of surfactant to other inhibitory agents, such as albumin. Thus, relatively low concentrations of PLC and PLA2 can cause severe breakdown of surfactant function and may contribute significantly to some forms of lung injury.

Animals↗
PubMed1979

Incidence of 'dry tap' on bone marrow aspirations in lymphomas and carcinomas. Diagnostic value of the small material in the needle.

Of 2907 bone marrow aspirations in patients with various malignancies, 192 or 6.6% exhibited 'dry tap'. In about 80% of the 'dry tap' there was material present inside the bone marrow needle which gave smears useful for evaluation of the bone marrow cytology. About 23% displayed normal cytology. Bone marrow involvement could be diagnosed in 13 out of 55 'dry tap' in Hodgkin's disease, 41 out of 46 in chronic lymphocytic leukaemia and lymphosarcoma, 6 out of 20 in reticulum cell sarcoma, 6 out of 9 in myelomatosis and 20 out of 45 in carcinoma. In a material of 174 aspirations with tumour cells in the bone marrow aspirate, the highest incidence of 'dry tap' was found in patients with Hodgkin's disease and patients with carcinoma, the lowest incidence in patients with multiple myeloma.

Biopsy, Needle↗
PubMed1979

Time of exchange of 131I-labeled albumin between plasma and peripheral lymph in man.

The passage from blood to peripheral lymph of 131I-labeled human serum albumin has been studied in 6 male patients (30-70 years) with malignancies without metastases. On the first day the concentration of radio-labeled albumin in the blood was kept almost constant by repeated i.v. injections. Lymph was collected continuously from a cannulated subcutaneous lymph vessel on the leg. Two hours after the first i.v. injection of radiolabeled albumin the lymph contained significant amounts of radioactivity in all patients. Equilibrium between radioactivity in blood and lymph was reached after 26 hrs. This indicates a long "wash out time" of unlabeled protein in the interstitial tissue from where lymph has been sampled.

Adult↗
PubMed1978

The significance of bone marrow acid phosphatase in patients with prostatic carcinoma.

The levels of total and l-tartrate labile acid phosphatase were studied in 49 patients with prostatic carcinoma. The results were compared with the results from a control group. The acid phosphatase levels from the bone marrow were above the upper normal limit of serum acid phosphatase both in the control group and in patients with prostatic carcinoma. This may be due to acid phosphatase released from blood cells during haemolysis. There was a positive correlation between serum and bone marrow acid phosphatase levels in patients with prostatic carcinoma. Significantly raised levels of bone marrow acid phosphatase (above the upper limit of the normal range from the control group) were observed only in advanced stage IV patients with significantly increased serum levels. The levels of bone marrow acid phosphatase gave no supplementary diagnostic information in any of the patients with prostatic carcinoma. Doubt is expressed concerning the hypothesis that raised levels of bone marrow acid phosphatase are diagnostic of early metastases from prostatic carcinoma.

Acid Phosphatase↗
PubMed1978

Cells in peripheral leg lymph of normal men.

The cells of human peripheral lymph collected from leg lymphatic of healthy volunteers have been studied by light- and electron microscopy. More than 80% of the cells were lymphocytes. The rest of the cells were neutrophils, monocytes, phagocytes, intermediate forms between lymphocytes and monocytes, erythrocytes and large cells. Ultrastructurally these large cells had many features in common with the Langerhans cells of normal epidermis and may represent this cell type or a closely related one.

Adult↗
PubMed1977

Twenty-four hour variation in flow and composition of leg lymph in normal men.

The twenty-four hour variation in concentration and output of total protein, lactate dehydrogenase and alkaline phosphatase has been studied in the peripheral lymph from the legs of 5 healthy volunteers over a period of five days. The highest concentration of these proteins was found in lymph collected during the first two hours after a night's rest. During the day a continuous decrease in concentration occurred without any direct correlation to lymph flow. The variation in lymph protein concentration between early morning and late day was about 40%, lactate dehydrogenase and alkaline phosphate about 90% and 45% respectively.

Adult↗
PubMed1977

Flow and composition of leg lymph in normal men during venous stasis, muscular activity and local hyperthermia.

Changes in normal human leg lymph protein concentration, output, and lymph flow/lymph protein concentration relationship, as well as lactate dehydrogenase and alkaline phosphatase activity were followed during procedures known to increase capillary filtration as venous stasis, muscular exercise and warming of tissues. Lymph flow increased by 83% during two hour ergometer cycling, and by 117% during two hour warm water foot bath. During a two hour period of venous stasis lymph flow dropped by 50%. There was an increase in lymph flow during the rest period following all three types of experiment, most pronounced after foot warming. An inverse relationship between the lymph flow rate and lymph protein concentration was found. Lymph enzymes followed the same pattern of changes as total protein.

Adult↗
PubMed1977

Variation in output of leukocytes and erythrocytes in human peripheral lymph during rest and activity.

The output of lymphocytes, monocytes, granulocytes and erythrocytes in peripheral leg lymph from healthy volunteers has been followed during night and everyday activity, during and after venous stasis, ergometer cycling and warm foot bath and during immobilisation in horizontal position over two 24-hour periods. The output of lymphocytes exceeded the output of monocytes and erythrocytes. Granulocytes were not found except immediately after cannulation. The cell output was low during night rest and the horizontal position for 24 hours. After assumption of the upright position the output of lymphocytes increased about 80 times and the output of erythrocytes 40 times probably because of washout of cells accumulated in tissue during rest. During ergometer cycling and venous stasis the output of cells increased and even more in the one hour rest period following this experiment. During venous stasis the output dropped but increased after the stasis had been released. The pattern of variation in lymphocyte, erythrocyte and monocyte output was the same. This indicate that the fluctuation in output depends on variation in blood flow in the tissue. The output of cells during and after heating seems to be dependent also on increased capillary permeability for cells as the output of erythrocytes exceeded the output of lymphocytes. The high erythrocyte/lymphocyte ratio in blood versus a low ratio in lymph shows that these two cell types pass through the capillary wall by different mechanisms.

Adult↗