How to produce a pulsatile flow with low haemolysis?

It is evident that a pulsatile flow is important for blood circulation because the flow pulsatility can reduce the resistance of peripheral vessels. It is difficult, however, to produce a pulsatile flow with an impeller pump, since blood damage will occur when a pulsatile flow is produced. Further investigation has revealed that the main factor for blood damage is turbulence shear, which tears the membranes of red blood cells, resulting in free release of haemoglobin into the plasma, and consequently leads to haemolysis.

Occipital posterior and occipital transverse positions: reappraisal of the obstetric risks.

Malpositions in labour in a vertex-presenting fetus are known to be associated with increased risks of operative delivery A retrospective analysis of all deliveries over 4 years in a university teaching obstetric unit was performed using the available obstetric database. All cases of live births with cephalic presenting babies after 36 completed gestational weeks were analysed, and included 17,533 out of 20,533 total deliveries over the study period. The study group included those cases with occipital posterior and transverse positions, based on the documentation of the position of the vertex at the time of delivery, or at the last clinical examination before obstetric intervention, while occipital anterior cases constituted the control group.

[A self-adaptable system for acquiring and processing animal ECG parameters].

The present authors have developed a computerized system for acquiring and processing the animal ECG. The system provides many functions in the software design and the users can compile the parameter-analyzing formulae by themselves according to the characteristics of ECG. The system is much more accurate and flexible in analyzing the ECG parameters and can significantly avoid the processing mistakes caused by signal variations and interference.

Bartter's syndrome in pregnancy: a case report and review.

Bartter's syndrome is a rare renal tubular disorder, involving juxtaglomerular cells hyperplasia, characterized by normotensive hyper-reninism and secondary hyperaldosteronism, marked renal loss of potassium and profound hypokalaemia. Both clinical and biochemical features are heterogeneous, ranging from the incidental finding in an asymptomatic patient to marked clinical features of hypokalaemia. Inheritance is likely to be an autosomal recessive.

Cyclooxygenase-2 is required for tumor necrosis factor-alpha- and angiotensin II-mediated proliferation of vascular smooth muscle cells.

Tumor necrosis factor-alpha (TNF-alpha) and angiotensin II (Ang II) induced a transient increase in vascular smooth muscle cell (VSMC) cyclooxygenase-2 (COX-2) mRNA accumulation, without affecting COX-1 mRNA levels. The kinetics of COX-2 mRNA accumulation were similar in VSMCs challenged with either TNF-alpha or Ang II; mRNA accumulation peaked at 2 hours and decreased to control levels by approximately 6 hours. Accumulation of COX-2 mRNA was associated with a time-dependent increase of COX-2 protein expression that displayed similar kinetics in response to either TNF-alpha or Ang II.

[The prevention of autoimmune kidney lesions developing in long-term exposure to epoxy compounds].

Clinical and biochemical, immunological and histological studies made in animals under inhalation exposure to volatile components of a new epoxy resin have yielded evidence in support of the development of autoimmune pathology (glomerulonephritis). One-stage determination of the amount of the blood serum circulating immune complexes and of the degree of sensibilization of bodily immunocompetent cells to a chemical (epichlorhydrin) and tissue (kidney) allergens in whole blood are regarded as a test for early diagnosis of glomerulonephritis. The enterosorbent "Ensoral" inhibits the development of those autoimmune processes being caused by bodily exposure to high concentrations of volatile components of epoxy resins.

[Microdialysis study of tolcapone effect during blockage of neuronal dopamine reuptake caused by GBR-12909].

In vivo brain functions analysis was conducted to assess the effect of tolcapone, a novel catechol-O-methyltransferase (COMT) inhibitor on extracellular levels of dopamine (DA) and its metabolites dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA) in the striatum of awake, freely moving eats during GBR 12909-induced blockade of DA uptake. Tolcapone administration (30 mg/kg, i.p.

Effects of osteogenic protein-1 (OP-1, BMP-7) on bone matrix protein expression by fetal rat calvarial cells are differentiation stage specific.

Bone morphogenetic proteins (BMPs) are a group of cytokines that are characterized by their ability to stimulate osteoblast differentiation and bone formation. However, the influence of BMPs on osteoblastic cells at different stages of differentiation is not known. Since bone matrix proteins are differentially regulated during bone formation we have studied the effects of recombinant human osteogenic protein-1 (rhOP-1; BMP-7) on the expression of these proteins by fetal rat calvarial cells (FRCCs) at discrete stages of osteoblast differentiation.

[Immune system function in the participants in the cleanup of the aftermath of the accident at the Chernobyl Atomic Electric Power Station].

Imbalance was revealed in the proportions of T-lymphocyte subpopulations in those persons engaged in activity in mining employment who had been exposed to a complex of the radiation accident factors. Maximum reduction in the lymphocyte suppressor activity was recordable in those patients in whom the doses of radioactive irradiation received exceeded 25 s Gy. Depression was found of humoral immunity manifested by a drop in the absolute as well as relative numbers of B-lymphocytes and fall in the blood serum levels of Ig G, A.

Inter-observer variability of portal hemodynamics measured by Doppler ultrasound on three different locations of portal vein.

Doppler ultrasound is a noninvasive modality for portal hemodynamic study. However, inter-observer variability has been observed. This study has investigated ways to produce less inter-observer variability.

Influence of osteogenic protein-1 (OP-1;BMP-7) and transforming growth factor-beta 1 on bone formation in vitro.

The bone morphogenetic proteins (BMPs) and transforming growth factor-beta s (TGF-beta s), are a group of structurally related proteins which have been shown to stimulate bone formation in vivo. Since these proteins are concentrated in the organic matrix of bone and would be released during bone resorption, they are likely to have a profound effect on the remodeling bone and may provide a link between bone resorption and bone formation. We are using primary cultures of fetal rat calvarial cells (FRCC) to study the independent and combined effects of OP-1/BMP-7 and TGF-beta 1 on bone cells at different stages of differentiation in order to identify responding cell populations and target genes.

[Non-significant in univariate but significant in multivariate analysis: a discussion with examples].

Perhaps as a result of higher research standard and advancement in computer technology, the amount and level of statistical analysis required by medical journals become more and more demanding. It is now realized by researchers that univariate analysis alone may not be sufficient, especially for complex data sets. Additional, and sometimes even contradictory, results may be found using multivariate analysis.

Regulation of osteopontin expression in osteoblasts.

Osteopontin (OPN) is a prominent bone matrix protein that is synthesized by osteoblastic cells. To elucidate the function of OPN in bone we studied the regulated expression of the rat OPN protein during bone formation in vivo and in vitro. OPN mRNA is expressed by preosteoblastic cells early in bone formation, but the highest expression is observed in mature osteoblasts at sites of bone remodelling.

Activation of procollagenase IV by cytochalasin D and concanavalin A in cultured rat mesangial cells: linkage to cytoskeletal reorganization.

The secretion and activation of procollagenase IV were studied in cultured rat mesangial cells. Under resting conditions, mesangial cells secrete predominantly a protein that, by gel zymography, exhibits gelatinase activity and also reacts with an anti-72-kd procollagenase IV antibody raised against a conserved region of the activation site of the enzyme. Cytochalasin D or concanavalin A treatment of mesangial cells causes disruption of actin stress fibers and results in the activation of procollagenase IV, yielding two lower molecular mass forms with gelatinase activity.

Embryoid Formation by High Temperature Treatment from Multiple Shoots of Panax ginseng1.

We developed a new technology to induce embryoids by a moderate high temperature treatment from multiple shoots of PANAX GINSENG (Araliaceae). The number of formed embryoids was 10 times higher than that of untreated tissue. Normal plantlets were regenerated from the embryoids by transplanting them on a hormone-free medium.

Stimulation by estrogen and progesterone of the in vivo growth of transformed murine Leydig cells only at the limited early phase of growth.

B-1 F is a cell line established from estrogen-responsive murine Leydig cell tumor and maintained in vitro. We investigated the effects of steroid hormones on the growth of tumors produced by the inoculation of B-1 F cells into mice. When tumor tissues were transplanted into castrated male mice, injections of estradiol-17 beta (E2) or progesterone shortened the period before tumors became palpable, but did not affect the growth rates of tumors after tumors became palpable.

Thymidylate synthetase gene as a quantitative mutation marker in Chinese hamster cells.

A quantitative mutation marker for cultured mammalian cells is presented which uses a selective medium containing folinic acid, aminopterin and thymidine (the 'FAT' medium) to select for mutants deficient in thymidylate synthetase (TS) activity. Optimization of FAT medium was carried out using Chinese hamster V79 cell lines having 3 levels of TS activity. By manipulating the concentration of folinic acid in FAT medium, TS-deficient mutants can be readily selected.

Single-step selection of mammalian cell mutants deficient in CTP synthetase.

A single-step selection of Chinese hamster V79 cells deficient in CTP synthetase (CTPS-) is presented. The underlying principle of the direct selection is the differential and efficient killing of synchronized wild-type cells through incorporation of [3H]uridine and [3H]thymidine. The CTPS- mutant cells were recovered by virtue of their not engaging in DNA synthesis, because (1) CTPS- cells are deficient in CTP synthetase and thus are unable to convert [3H]UTP into [3H]CTP, which eventually is converted into [3H]dCTP and incorporated into DNA; (2) the growth of CTPS- mutant cells was arrested as a result of cytidine deprivation, thus escaping the killing by the incorporation of [3H]thymidine.

Evaluation of methods for the estimation of mutation rates in cultured mammalian cell populations.

A systematic comparison of 5 different statistical methods for the estimation of mutation rate (mu) in cultured Chinese hamster V79 cells is presented. Fluctuation tests were performed with several large batches of parallel cell cultures each allowed to grow for a different length of time in order to reach different population size (Nt). Based on Lea and Coulson's theoretical distribution, a comparison has been made between the experimental data and the expected distribution of the number of ouabain-resistant mutants per culture in these hamster cell populations.