Showing papers by "Gdańsk Medical University published in 1997"

Chemically Bonded Silica Stationary Phases: Synthesis, Physicochemical Characterization, and Molecular Mechanism of Reversed-Phase HPLC Retention

Abstract: Two types of chemically bonded phases for high-performance liquid chromatography (HPLC) have been prepared: a conventional C18 and AP (N-acylaminopropylsilica), a novel one that contains specific interaction sites localized in the hydrophobic chain. Surface properties of stationary phases, before and after chemical modification, have been characterized by several physicochemical techniques, such as porosimetry, ICP atomic emission spectroscopy, elemental analysis, solid state CP/MAS NMR, and chromatography. For the studies of the reversed-phase HPLC retention mechanism under hydroorganic conditions, a test series of structurally diverse solutes has been selected. Sets of retention parameters and structural descriptors of the test solutes were subjected to multiparameter regression analysis. The quantitative structure−retention relationships derived demonstrated the typical reversed-phase partition mechanism to predominate in the separation on the C18 phases but not on the AP phases. The AP phases were de...

Unusual increase of lipogenesis in rat white adipose tissue after multiple cycles of starvation-refeeding

Abstract: The purpose of the study was to determine the response of liver and brown (BAT) and white (WAT) adipose tissue lipogenesis and total body weight in rats subjected to multiple cycles of 3 days of fasting and 3 days of refeeding. Rats fasted for 3 days showed significant reduction in body weight. These changes were reversed on 3 days' refeeding. Body weight was much higher in rats fed ad libitum than in animals experiencing more than one cycle of 3 days of fasting followed by 3 days of refeeding. Despite the significant body weight reduction, an unusual increase of lipogenesis in WAT was found after multiple cycles of starvation-refeeding of rats on standard laboratory diet. The rate of lipogenesis in the liver and BAT was also elevated but to a much smaller extent. A parallel increase in enzymatic activities related to fatty acid synthesis, ie, fatty acid synthase, acetyl-coenzyme A carboxylase, adenosine triphosphate (ATP)-citrate lyase, NADP-linked malic enzyme, and hexose monophosphate shunt dehydrogenases, suggests that the increased rate of lipogenesis in WAT is a consequence of increased lipogenic enzyme activities. These data suggest that upregulation of WAT lipogenesis occurs after the multiple cycles of the starvation-refeeding protocol. An unusual increase of lipogenesis in rat WAT may have a survival advantage, because starved-refed rats must develop the ability to ingest large amounts of food during a refeeding period to store it in a convenient form than can be used as an oxidizable substrate during a period of starvation. Moreover, these results suggest that it is possible to develop appropriate starvation-refeeding conditions that may inhibit body weight gain.

Distribution and Association of Trace Metals in Soft Tissue and Byssus of Mytilus edulis from the East Coast of Kyushu Island, Japan

Abstract: Concentrations of Cd, Pb, Zn, Cu, Ag, Cr, Co Ni, Mn, and Fe in soft tissues and byssi of blue mussel (Mytilus edulis) from three sites along the east coast of Kyushu Island, Japan, were determined by AAS method. Large inter-regional differences in metal concentrations in both soft tissues and byssi (Cu, Cd, and Pb and Cu, Pb, Co, Ni, Mn, and Fe, respectively) were recorded. Highly significant correlations (p < 0.01) were observed between tissue and byssal concentrations of Pb, Cu, Zn, and Mn. The tissue concentrations of Cu, Cd, and Pb were two orders of magnitude greater in Mytilus edulis from expected to be the most contaminated locations compared to those from a nonindustrialized area. Intercomparison of the present study data with those published previously indicates that the soft tissue and especially byssus are useful in detecting some areas of some metallic contaminants. The high concentrations of Cd, and especially Pb and Cu, in Saganoseki mussels and moderately elevated concentrations of these metals in Akamizu mussels may be attributed to the anthropogenic emissions from a metallic refinery and an artificial fiber factory, respectively. It is evident that, compared to the soft tissue, the increase of Cu levels relative to Zn levels in the byssi of M. edulis are eight times higher, with a slope b (Cu/Zn) of 7.5 for byssus and 0.93 for soft tissue. This suggests that byssus, as compared to soft tissue, is a more sensitive bioindicator for Cu. From the data obtained, the soft tissue and especially byssi of M. edulis appear to be good bioindicators for identification of coastal areas exposed to metallic contaminants.

Prognostic implications of cytogenetic findings

Abstract: Objective. To evaluate the prognostic impact of cytogenetic findings in renal cell carcinoma (RCC). Patients and methods. Tumour cytogenetics, histomorphology, DNA ploidy and S-phase fraction, stage, size, and grade were related to survival in 50 consecutive patients with RCC. The mean follow-up was 3.9 years (median 4.2. range 0-8.8). Results. The predictive probability for recurrence-free survival at 5 years (5-year RFS) for all 50 patients was 0.54. There was a significant association between the degree of cytogenetic complexity and survival, in that patients with five or less aberrations had a better prognosis than those with more than five changes (5-year RFS 0.71 and 0.43, respectively; P < 0.05). Patients with del(8p)/-8, +12, and +20 had a significantly worse prognosis compared with those without these aberrations. Of the well-known prognostic variables grade and stage, the former was far better for predicting prognosis. A Spearman correlation test showed a significant covariation of grade with the S-phase fraction, T-stage, and cytogenetic complexity. Conclusion. The degree of cytogenetic complexity and recurrent cytogenetic abnormalities affect the prognosis in RCC, although grade was the most reliable independent prognostic factor predicting disease recurrence. (Less)

A microscopic view of false tendons in the left ventricle of the human heart.

Abstract: Research was conducted on material consisting of 45 fetal, newborn, infant and adult human hearts. False tendons in fetal, newborn and infant hearts were made up of mainly heart muscle tissue. False tendons of the tendon attachment to the interventricular septum. These false composed of muscle tissue and connective tissue in various proportions. Most of the connective tissue was observed in this age group in the area of the tendin attachment to the interventricular septum. These false tendons turned out to be very richly vascularized. In some of them, elements of the conductive system was confirmed, being an extension of the left branch of the bundle of His. This may confirm the role of false tendons in heart arrhythmias.

Activity of 2-chlorodeoxyadenosine (cladribine) in 2-hour intravenous infusion in 94 previously treated patients with low grade non-hodgkin's lymphoma

Abstract: The purpose of our study was to determine the efficacy of 2-chlorodeoxyadenosine (2-CdA) administered in 2-hour intravenous infusions in previously treated patients with low grade non-Hodgkin's lymphoma (LGNHL). We treated 94 LGNHL patients with 2-CdA at a dosage of 0.12 mg/kg/24h in 2-hour intravenous infusion for 5 consecutive days. The treatment consisted of from 1 to 7 courses (median 3), repeated usually at monthly intervals. All patients were refractory to or relapsed after standard chemotherapy. Of these 94 patients 78 (83%) had clinical stage IV of the disease. Complete response (CR) was obtained in 12 (12.8%) and partial response (PR) in 36 (38.3%) giving an overall response rate of 51.1%. In 12 (12.8%) grade 4 thrombocytopenia with haemorrhagic diathesis was noted, grade 4 neutropenia was observed in 12 (12.8%) and infections complicated the course of treatment in 38 (40.4%) patients. 2-CdA treatment was the cause of death of 3 patients. The results of our study show that 2-CdA given in 2-hour i...

Structural Requirements of Phospholipase C δ1 for Regulation by Spermine, Sphingosine and Sphingomyelin

Abstract: We studied the relationship between sphingomyelin, calcium, spermine and sphingosine in regulation of phospholipase C (PLC) δ1 activity. Inhibition of PLC δ1 by sphingomyelin was promoted by spermine and Ca2+ and was partially abolished by sphingosine. The effect of sphingosine and spermine entirely depended on Ca2+. In the absence of Ca2+, no effect of these substances on PLC δ1 activity was observed. Using deletion mutants and active fragments of PLC δ1 generated by limited proteolysis, we have studied the structural requirements of the enzyme for regulation by these compounds. The deletion mutant of PLC δ1 lacking the first 58 amino acids and the mutant lacking the entire pleckstrin homology (PH) domain were fully active in the detergent assay, and their activities were affected by spermine, sphingosine, Ca2+ and sphingomyelin to the same extent as the native enzyme. The limited proteolysis of PLC δ1 generated two fragments of 40 kDa and 30 kDa, which formed a stable active complex. The relationship between Ca2+ concentration and enzymatic activity was almost identical for the native PLC δ1 and the proteolytic complex. The activity of the proteolytic complex formed by the 40 kDa and 30 kDa peptides was not affected by spermine and sphingosine. Sphingomyelin inhibited the complex slightly less than the native PLC δ1, and this inhibition was not promoted by spermine. These observations suggest that for activation of PLC δ1 by spermine and sphingosine, the region spanning domains of high conservation, named X and Y, must be intact. In contrast, the PH domain and the intact spanning region of the X and Y domains are not essential for inhibition of PLC δ1 by sphingomyelin.

Distribution of trace metals in the Pacific oyster, Crassostrea gigas, and crabs from the east coast of Kyushu Island, Japan

Abstract: Oysters are known to be exceptional accumulators of Zn and Cu, and their tissue concentrations appear to reflect contamination of metals. According to Lauenstein and Dolvin, oysters clearly have a greater affinity for Ag, Cu and Zn than do mussels, while mussels have greater affinity for Cr and Pb. Oysters have been considered to be potential bioindicators for monitoring metallic pollution in marine environments. Extensive investigations of oysters from the east coast of Kyushu Island, Japan, have been performed. The aim of the study was to examine spatial differences in metal concentrations in soft tissues of the Pacific oyster (Crassostrea gigas) and whole bodies (soft tissues with shells) of the crabs Goetice depressa and Leptodius exaratus inhabiting the Japanese coastal region of the Pacific. 18 refs., 3 figs.

Meningiomas of the lateral ventricles of the brain.

Abstract: Meningiomas of the lateral ventricles of the brain are rare tumours with an approximate incidence of 0.5-4.5% among all intracranial meningiomas. Four cases of intraventricular meningioma arising from the trigone are presented. In 1-st case the calcified mass was visible on straight radiographs. In 2-nd and 3-rd cases CT and angiography was performed. In 4-th case MRI and MRA proved to be very useful. The tumours were removed by transcortical approach in the posterior parietal area. The available literature on intraventricular meningiomas has been discussed.

Overactivity of Tumor Necrosis Factor-Alpha but Not Interleukin 6 Is Associated with Low Natural Killer Cytotoxic Activity in the Elderly

Abstract: In this paper we asked whether the increased production of two proinflammatory cytokines – tumor necrosis factor-α (TNFα) and interleukin-6 (IL6) in the absence of the inflammatory stimulus, a phenome

Clonal chromosome aberrations are present in vivo in synovia and osteophytes from patients with osteoarthritis.

Abstract: We have previously reported recurrent clonal chromosomal aberrations in synovia, osteophytes and articular cartilage from patients with osteoarthritis (OA). In particular, gain of chromosomes 5 and 7 was found to be strongly associated with OA. In order to exclude the possibility of in vitro artefacts, we studied three to four parallel, independent cultures from ten samples of synovia and three samples of osteophytes from ten women with primary OA. In all, 40 cultures were cytogenetically analysed, 39 of which had clonal chromosomal aberrations. The most common aberrations were +7 and +5 which were found in 38 and 12 cultures, respectively. There were striking karyotype similarities among the parallel cultures from each case. Out of a total of 83 clones, only 11 were unique for one culture, 7 from synovia and 4 from osteophytes. The genetic homogeneity among different cultures from the same patients excludes the possibility of in vitro artefacts and indicates a widespread distribution of the cytogenetically aberrant clones in vivo.

Expression, purification and kinetic properties of human recombinant phospholipase C delta 3.

Abstract: To obtain sufficient quantities of pure phospholipase C delta 3 (PLC delta 3) necessary for structural and kinetic studies, cDNA of human fibroblast PLC delta 3 was cloned in the pPROEX-1 vector, expressed in E. coli cells as a (6 x His) fusion protein and purified to homogeneity. From 1 L of E. coli culture 8 mg of pure PLC delta 3 was obtained by a two step purification procedure, which includes phosphocellulose and Mono S cation exchange chromatography. The presence of His tag did not affect the catalytic and regulatory properties of PLC delta 3. The K(app) for PIP2 was 142 +/- 11 and 156 +/- 12 microM for His.PLC delta 3 and PLC delta 3, respectively. Recombinant PLC delta 3 showed an absolute requirement for Ca2+. Increasing the free Ca2+ concentration from 0.2 to 0.5 microM resulted in a sharp increase in enzyme activity. In comparison with human recombinant PLC delta 1 the delta 3 isoenzyme was more sensitive to low Ca2+ concentration. The Ca2+ concentration yielding maximal activation of PLC delta 1 and PLC delta 3 was 10 and 1 microM, respectively. The activity of PLC delta 3 was stimulated by polyamines and by basic proteins such as protamine, histone and mellitin. PLC delta 3 was activated most effectively by spermine and histone but the extent of this activation was lower than for PLC delta 1. The data presented indicate that the expression of PLC delta 3 in E. coli cells permits to obtain active enzyme. The catalytic and regulatory properties of PLC delta 3 are similar to those of PLC delta 1.

Volume and topographical changes of the basolateral complex during the development of the rat's amygdaloid body.

Abstract: Volume and topography of basolateral complex during development and maturation in fetal and postnatal rat brains were studied using morphometrical methods. 39 rat brains of various ages were fixed in formalin, frozen and cut into 25-micron-thick sections and stained with cresyl violet. In cresyl violet preparation the basolateral complex appeared first on 17th prenatal day and it was composed of two homogenous parts--lateral and basolateral nuclei. On about 7th postnatal day each of these nuclei divided into two parts--the first one into the dorsolateral and ventromedial part, while the second one--into the anterior and posterior parts. Morphometric investigations showed that volume of the basolateral complex and its parts underwent the biggest changes up to 14th postnatal day, and we suspected that during this time it was more sensitive to pathological changes. After that day the volume of the basolateral complex had changed only a little.