Differences in hormonal and inflammatory parameters in male Lewis and Long Evans rats with adjuvant arthritis

The purpose of the present study was (i) to compare secretory responses of prolactin and corticosterone to the acute stress of immobilization in male rats of the Lewis and Long Evans strains and (ii) to compare secretion of the two hormones in rats with fully developed adjuvant arthritis (AA) and their relationship with the intensity of the inflammatory reaction. A short immobilization of 5 min induced equal elevations of both hormones in both strains, but 20-min immobilization produced significantly stronger responses in Long Evans rats than in Lewis rats. AA inhibited prolactin secretion equally in both strains (from 11.6 +/- 1.3 ng/ml to 4.2 +/- 0.6 ng/ml in Lewis rats, p < 0.01, and from 3.7 +/- 0.6 to 2.12 +/- 0.1 ng/ml in Long Evans rats, p < 0.05), but caused a conspiciously larger elevation of corticosterone in the Long Evans than in the Lewis animals (11.5 +/- 1.2 microg/dl in Long Evans rats versus 5.1 +/- 0.5 microg/dl in Lewis rats, p < 0.01) while basal levels were similar. The larger corticosterone response in the Long Evans rats was associated with a stronger inflammatory reaction assessed by hind paw swelling (2.3 +/- 0.1 ml for Long Evans rats versus 1.8 +/- 0.08 ml for Lewis rats, p < 0.01) and plasma levels of nitric oxide (47.5 +/- 5.7 microM for Long Evans rats versus 28.7 +/- 2.5 microM for Lewis rats, p < 0.01) than in the Lewis males with lower corticosterone levels. In conclusion, there are significant, obviously genetically based, differences in the corticosterone responses to both immobilization and AA between the two strains, with the Long Evans rats reacting more strongly than the Lewis rats. The lack of the expected inverse relationship between corticosterone levels and the intensity of the inflammation indicates that the activity of corticosterone is not its primary determinant and that other important factors are involved.     

Phosphatidylglycerolphosphate synthase encoded by the PEL1/PGS1 gene in Saccharomyces cerevisiae is localized in mitochondria and its expression is regulated by phospholipid precursors

The PEL1/PGS1 gene of the yeast Saccharomyces cerevisiae is essential for the viability of rho ^–/rho° mutants and the normal cardiolipin content of cells. The PEL1-GFP fusion gene has been found to complement the pel1/pgs1 mutation and its fluorescent protein was localized to mitochondria similarly to the β-galactosidase activity of a protein encoded by the PEL1-lacZ fusion gene. The expression of the PEL1-lacZ reporter gene was repressed in cells grown in the presence of inositol and choline, reduced in the ino2 and ino4 strains, but constitutive in the opi1 null-mutant strain. The results demonstrate that Pel1p, playing a vital role in cells impaired in the mitochondrial DNA, is localized in the mitochondria and expressed in response to inositol and choline. Received: 15 June / 15 July 1998     

Isolation of Tettnang virus from ticks, mosquitoes and small rodents.

Seven strains of Tettnang virus were isolated in Czechoslovakia: 3 from Ixodes ricinus tick nymphs, males and females, one from Dermacentor reticulatus tick females, one from Aedes cantans mosquitoes and two strains from the brains of Clethrionomys glareolus and Apodemus flavicollis small rodents.     

Antibody responses to the herpes simplex virus type 2 glycoprotein G in sera of human immunodeficiency virus-infected patients in Slovakia.

Thirty sera of human immunodeficiency virus-positive (HIV+) and 37 sera of HIV-negative (HIV-) individuals in Slovakia were tested for the presence of antibodies to herpes simplex virus type 2 (HSV-2) glycoprotein G (gG). A notable difference between the prevalence of HSV-2-specific antibodies in HIV+ and that in HIV- individuals was found (37% vs. 11%) confirming and extending previous reports that HSV-2 infection is an important risk factor for HIV transmission. Efforts toward the detection of HSV-2 infection and its therapy by anti-HSV drugs should be considered an important factor in decreasing the risk of contracting and spreading of HIV in Slovakia.     

The effects of hyaluronan on bone resorption and bone mineral density in a rat model of estrogen deficiency-induced osteopenia

Hyaluronan, or hyaluronic acid (HA), is an essential component of extracellular matrices. HA of appropriate molecular weight and concentration can induce osteoblast differentiation and bone formation in vitro. The aim of our study was to evaluate the effects of HA of different molecular weights on ovariectomy (OVX)-induced bone loss in rats. Adult female Sprague Dawley rats were subjected to bilateral OVX or sham surgical procedure (sham). OVX rats were treated with: HA of molecular weight of 0.75 MDa at a dose of 1 mg/kg/day and with HA of molecular weight of 1.62 MDa at a dose of both 0.5 mg/kg/day and 1 mg/kg/day. HA was applied orally once a day during the 8-week period after ovariectomy. Body weight, urinary pyridinoline (Pyr), deoxypyridinoline (DPyr) corrected for urinary creatinine, serum nitrite/nitrate concentrations and whole body and femoral bone mineral density (BMD) were measured. HA treatment had no effect on the body weight gain in OVX rats. Excretion of urinary Pyr and Dpyr significantly increased in OVX rats compared to sham controls. The higher molecular weight HA (1.62 MDa) significantly reduced urinary Pyr and DPyr concentrations measured on day 28 after ovariectomy (p < 0.001). Serum concentrations of nitric oxide metabolites, nitrite/nitrate significantly decreased in OVX rats in comparison with sham controls (p < 0.001). HA of both 0.75 MDa and 1.62 MDa molecular weights significantly enhanced serum nitrite/nitrate concentrations in OVX rats. There was a clear reduction of whole body and femoral BMD in untreated OVX rats. The higher molecular weight HA decreased both whole body and femoral BMD loss. Our results show that orally applied HA of high molecular weight (1.62 MDa) inhibits bone resorption and provides a protective effect on bone density in ovariectomized rats.     

Hepatitis B virus proteins expressed by recombinant vaccinia viruses: influence of preS2 sequence on expression surface and nucleocapsid proteins in human diploid cells

Summary Translation of poliovirus RNA is initiated by entry of ribosomes into the nucleotide sequence (internal ribosomal entry site; IRES) within the 5-untranslated region (5-UTR). Efficiency of this translation initiation in rabbit reticulocyte lysates (RRL) was very low and was greatly enhanced by addition of the ribosomal salt-wash fraction (RSW) prepared from HeLa cells. This stimulating activity in the RSW was partially purified by gel-filtration column chromatography and its molecular weight was estimated to be higher than 240 000. Several proteins that bind specifically to the poliovirus IRES were detected in the active fraction. Among those, a 57 kDa protein, recognized by antibodies against polypyrimidide tract-binding protein (PTB), was found. In addition, La protein (52 kDa) which is a human antigen recognized by antibodies from patients with autoimmune disorders was also detected. Further purification on a hydroxylapatite column resulted in considerable loss of the stimulatory activity, accompanied by a reduction of the apparent molecular weight of active component(s). These results suggest that fully active HeLa cell stimulatory factors for the translation initiation on poliovirus RNA function in RRL as a large complex consisted of several components including PTB and La protein.     

Micropapillary carcinoma of the parotid gland arising in mucinous cystadenoma

We describe a 45-year-old man who had a 2-year history of a slowly enlarging tumor in the left parotid gland. Histologically, the tumor was a mucinous cystadenoma with focal apocrine differentiation, which revealed a widespread invasive micropapillary adenocarcinoma component. A rim of lymphoid tissue surrounded the margins of the micropapillary carcinoma. The invasive micropapillary adenocarcinoma component was morphologically identical with the invasive micropapillary carcinoma of the mammary gland. The tumor is different from so-far recognized salivary gland tumor entities. Received: 25 October 1999 / Accepted: 13 June 2000     

Defects of natural killer cell activity in children with untreated acute lymphocytic leukemia

Summary Natural killer (NK) activity against cells of the K-562 line was significantly depressed in 12 of 18 children (66%) with untreated acute lymphocytic leukemia (ALL). No suppression of allogeneic NK activity was observed with sera of the patients, regardless of the level of NK depression. The ability of peripheral blood lymphocytes (PBLs) to suppress allogeneic NK activity was tested in two ALL patients — one with no detectable NK activity, and one with high NK activity. No NK-suppressive activity was found with PBLs of the areactive patient; PBLs of the reactive patients exhibited some suppressive activity, but only at a particular suppressor-to-effector cell ratio. Leukemic blasts were resistant to killing by autologous NK cells stimulated by IFN, as well as to killing by allogeneic, IFN-stimulated PBLs. Leukemic blasts of an ALL patient inhibited lysis of K-562 cells in an 18-h, but not in a 4-h NK assay. The inhibition could partly be reversed by pretreatment of ALL cells with alpha interferon, suggesting that the blasts might inhibit the lysis of K-562 targets in a competitive manner. Disturbed function and/or regulation of NK cells may influence attempts at NK cell activation by lymphokines.Abbreviations ALL acute lymphocytic leukemia - AML acute myeloid leukemia - CLL chronic lymphocytic leukemia - CML chronic myeloid leukemia - IFN interferon - IL-2 interleukin-2 - LGL large granular lymphocyte - NK cell natural killer cell - PBL peripheral blood lymphocyte - Poly I:C polyinosinic-polycytidylic acid