Induction of telomerase activity by UV-irradiation in Chinese hamster cells

Telomerase is a ribonucleoprotein whose activity has been detected in germline cells and in neoplastic and immortal cells. Telomerase compensates the telomere loss arising by the end replication problem by synthesizing telomeric repeats at the 3' end of the eukaryotic chromosomes. Telomerase is reactivated during cancer progression in human and mice. In order to determine whether the telomerase activity can be upregulated in vitro in response to DNA damaging agents, we examined the telomerase activity in five Chinese hamster cell lines following exposure to 5 J/m2 or 40 J/m2 UV-C radiation. All the cell lines tested showed an increase in telomerase activity in the PCR-based telomeric repeat amplification protocol (TRAP) in a dose dependent manner. This increase in telomerase activity correlated well with the number of cells being in the S and G2/M phase after UV exposure. However, in unirradiated control cells, similar levels of telomerase activity were observed in different phases of the cell cycle. Furthermore, telomeric signals were clustered in one or more parts of the disintegrating nuclear particles of the apoptotic cell as detected by fluorescence in situ hybridization (FISH). This is the first study to demonstrate the induction of telomerase activity following exposure to DNA-damaging agents like UV radiation in Chinese hamster cells in vitro.     

Pulmonary surfactant protein SP-B interacts similarly with dipalmitoylphosphatidylglycerol and dipalmitoylphosphatidylcholine in phosphatidylcholine/phosphatidylglycerol mixtures

Porcine pulmonary surfactant-associated protein SP-B was incorporated into bilayers of chain-perdeuterated dipalmitoylphosphatidylglycerol (DPPG-d62) and into bilayers containing 70 mol % dipalmitoylphosphatidylcholine (DPPC) and 30 mol % DPPG-d62 or 70 mol % chain-perdeuterated DPPC (DPPC-d62) and 30 mol % DPPG. The effect of SP-B on the phase behavior, lipid chain order, and dynamics in these bilayers was examined using deuterium nuclear magnetic resonance (2H-NMR). In both DPPG-d62 and the mixed lipid system, SP-B is found to have little effect on chain order in the liquid crystalline phase. With 11% (w/w) SP-B present, both bilayer systems display a continuous change from liquid crystal to gel with no evidence of two-phase coexistence near the transition. Despite its limited effect on chain order in these bilayers, SP-B is found to strongly perturb chain deuteron transverse relaxation in the liquid crystal and gel phases of DPPG-d62 and the DPPC/DPPG (7:3) mixtures. The observation that SP-B associates with the bilayer in a way which substantially alters the slow motions responsible for transverse relaxation without significantly affecting chain order in either the liquid crystal or gel phases may place some constraints on possible models for that association.     

Autologous lymphokine-activated killer cell therapy of Epstein-Barr virus-positive and -negative lymphoproliferative disorders arising in organ transplant recipients

Lymphoreticular malignancies, collectively called posttransplant lymphoproliferative disorders (PTLD), eventually develop in 2-5% of organ transplant recipients. They frequently undergo regression when immunosuppression is reduced or stopped. This feature has been associated with a previous or de novo Epstein-Barr virus (EBV) infection. We herein describe immunotherapy with autologous lymphokine-activated killer (LAK) cells in seven patients with PTLD (four EBV-positive patients and three EBV-negative patients). Autologous peripheral blood mononuclear cells were obtained by leukapheresis, depleted of monocytes, and cultured in the presence of interleukin 2 for 10 to 11 days. A single dose of 5.2 x 10(9) to 5.6 x 10(10) LAK cells was given intravenously. Systemic interleukin 2 was not administered. The four patients with EBV+ PTLD had complete tumor regression; two of them developed controllable rejection. Three patients are well 13-16 months after treatment; the fourth patient died of pneumonia 41 days after infusion. Three patients with EBV- lymphomas had no response despite prior evidence that their tumors also were subject to immune surveillance. Two of these three patients died after being given other treatment, and the third patient has persistent tumor. In conclusion, autologous LAK cell infusion was effective for treatment of four EBV+ organ transplant recipients. LAK cell efficacy for three patients with EBV- PTLD was not evaluable under the management circumstances in which this treatment was utilized.     

High-performance liquid chromatographic determination of bisacodyl in pharmaceutical dosage forms marketed in Australia

HPLC methods have been developed for the assay of bisacodyl in various pharmaceutical forms. The extraction procedures are simple and the HPLC conditions separate bisacodyl from its degradation products. The chromatography was performed using a Merck LiChrospher RP-select B column, a mobile phase of 55% acetonitrile/45% 0.05 M KH2PO4 and detection by UV at 214 nm.     

Mesenteric vasculopathy in intestinal tuberculosis

BACKGROUND: Involvement of mesenteric vessels in intestinal tuberculosis and its role in the pathogenesis of the intestinal changes have not been studied histologically. AIM: To study mesenteric vessels in patients undergoing surgery for complications of intestinal tuberculosis. METHODS: Resected intestinal specimens from 68 patients presenting with intestinal perforation and intestinal obstruction were examined; involvement of the major mesenteric vessels was evaluated. RESULTS: Granulomas were seen in the vessel wall in one case and near the vessel wall in 11 cases, intraluminal thrombi were seen in 23 cases, and subintimal fibrosis in nine cases. Perivascular cuffing was seen in intramural and subserosal vessels in ten cases. CONCLUSIONS: Changes in the vessel wall may lead to gut ischemia, which may contribute to the development of strictures and stercoral perforation in intestinal tuberculosis.     

Cryoprecipitate prepared from plasma virally inactivated by the solvent detergent method

The newly discovered peptide nociceptin/orphanin FQ has been found to increase reactivity to pain and to influence locomotor activity after intracerebroventricular administration. This study investigated the possible role of hippocampal nociceptin/orphanin FQ in spatial learning and in spontaneous locomotion. Male rats were trained in the Morris water task after microinjection of 10 nmol nociceptin/orphanin FQ or artificial cerebrospinal fluid (as control) into the CA3 region of the dorsal hippocampus. Nociceptin/orphanin FQ was found to severely impair spatial learning without interfering with swimming performance. Intrahippocampal injection of nociceptin/ orphanin FQ markedly decreased exploratory locomotor activity including vertical movements (rearing). The data suggest that nociceptin/orphanin FQ is a potent modulator of synaptic plasticity within the hippocampus.     

Ganciclovir induces reproductive hazards in male rats after short-term exposure

1. The effect of short-term treatment of ganciclovir on male reproduction in adult rats was studied. The animals were treated subcutaneously with either a single dose of 60 mg/kg daily for 5 days (Gan5day) or with 100 mg/kg administered three times at 4 h-intervals (Gan1day). The effects were investigated every 2 weeks up to 8 weeks, followed by investigations 16 and 24 weeks after treatment to detect the potential of recovery. 2. Time to mating was significantly increased in Gan1day group. The pregnancy index and outcome were only decreased 8 weeks (Gan5day and Gan1day) or 16 weeks (Gan1day) after treatment. 3. The lowest values of sperm variables studied were registered 8 weeks after treatment: The number of spermatid was reduced up to 4% (Gan5day) or 2% (Gan1day) of control; the sperm number was 5% and 8% of control in Gan5day and Gan1day, respectively. Over 80% of sperm were abnormal in Gan5day group, and only few normal sperm was detected in Gan1day group. 4. Morphological investigation of testes revealed a clearcut time-dependency effect. Four weeks after treatment distinct alterations were located exclusively in the peripheral part of the tubuli which included fat inclusions, cell and pyknotic nuclear debris and swellings of Sertoli cells. The effect was reversible 24 weeks after treatment. 5. Ganciclovir induces testicular damage and affects sperm variables after short-term exposure. The intensity and degree of the hazards varied in between the time of investigation after treatment.     

Sunlight and sunburn in human skin cancer: p53, apoptosis, and tumor promotion

Levels of allergen-specific IgE and IgE antibodies were determined in serum samples from 60 atopic and 11 normal dogs by means of commercially available ELISA test kits and a panel of 33 allergens. In the atopic population, IgE antibodies were most commonly identified with a specificity for Dermatophagoides farinae (78.3 per cent of affected dogs), D pteronyssinus (61.6 per cent), mould mix (25 per cent) and house dust (19 per cent), whereas the most frequently detected IgG antibodies had a specificity for D farinae (38.3 per cent), D pteronyssinus (33.3 per cent), mould mix (33.3 per cent), insect mix (16.6 per cent) and meadow fescue (16.6 per cent). The IgG subclass profile of allergen-specific antibodies was determined for five representative allergens from the panel. The IgG response to D farinae and D pteronyssinus was dominated by IgG4 antibodies, although lower levels of IgG2, and IgG3 and IgG1 D pteronyssinus antibodies were also detected. The IgG response to Timothy grass was predominantly within the IgG1 and IgG4 subclasses, IgG subclass selection in the response to mould mix and insect mix was broader, with relatively low level reactions from all four subclasses. The data suggest a degree of IgG subclass restriction in the humoral immune response of canine atopy which may be dependent upon the nature of the allergen.