Localization of G-proteins in macrophages and E. coli during phagocytosis

Heterotrimeric GTP-binding proteins (G-proteins) have been shown to play an important role in cellular signalling. However, G-protein involvement in the intracellular spreading of bacterial pathogens is still poorly understood. In this study, antibodies, that recognize G-protein alpha-subunits (anti-G alpha), were used to investigate the localization of G-proteins in the macrophage-like cell line P388D1 and E. coli, also in their L-forms, during phagocytosis. In E. coli, anti-G alpha-binding sites were detected preferably in the cell wall and septa of the whole bacterial forms as well as in the cytoplasm of L-forms. Western blotting of bacterial lysates demonstrated protein bands with positive immunoreaction to antibodies against Gs alpha, Gi alpha, and Gcommon alpha with a higher affinity to the antibody against Gs alpha. Immunoreaction with the anti-Gs alpha-antibody was markedly higher in pathogenic strains of E. coli. Because of the conserved structure in all GTP-binding proteins which seem to derive from a single primordial protein involved in signal transduction mechanisms, it is reasonable to assume that some anti-Ga-positive proteins in E. coli might be related to G-proteins of higher organisms. A putative candidate for bacterial G-proteins seems to be a 36 kDa protein. Enhancement in G-protein immunostaining in the cytoplasm of macrophages around the internalized bacteria testifies to the involvement of G-proteins in mediation of endocytosis responses of phagocytes.     

Health outcome improvements in patients with systemic lupus erythematosus using two telephone counseling interventions

OBJECTIVE: To examine the effectiveness of two telephone intervention strategies for improving the health outcomes of patients with systemic lupus erythematosus (SLE). METHODS: Fifty-eight SLE patients were randomly assigned to receive a 6-month telephone counseling intervention using either a treatment counseling (TC) or symptom monitoring (SM) strategy. Health outcomes were assessed using the Fatigue Severity Scale (FSS) and the Arthritis Impact Measurement Scales 2 (AIMS2). RESULTS: At the 6-month followup, the mean AIMS2 Physical Function scale and AIMS2 Social Support scale scores were significantly improved (P < 0.05) for the TC group compared to the SM groups. The mean FSS score, AIMS2 Affect score, and AIMS2 Pain score were significantly improved (P < 0.05) for both groups. CONCLUSIONS: Telephone interventions, especially using the TC approach, can be effective for improving the functional status of persons with SLE.     

Polymeric prodrugs of mitomycin C designed for tumour tropism and sustained activation

Prodrugs of mitomycin C (MMC) based on soluble poly-[N-(2-hydroxyethyl)-L-glutamine] (pHEG) polymers have been evaluated as tumour-targeted drugs. These materials are designed to exploit the enhanced permeability of tumour vasculature, combining a passive tumour tropism with decreased systemic liberation of free MMC. A tri- or tetrapeptide linkage (e.g. Gly-Phe-Ala-Leu) between pHEG and the aziridine nitrogen of MMC can combine good hydrolytic stability with rapid cleavage by lysosomal enzymes, releasing free MMC. The conjugates showed decreased systemic toxicity and could be administered to mice at a total MMC dose of 15 mg/kg i.v., compared with just 6 mg/kg for free MMC. Conjugates also showed better activity against animal models of established tumours, achieving up to 77% increased life span (ILS) against solid P388 leukaemia, compared with only 23% for free MMC, and up to 121% ILS against solid C26 colorectal carcinoma, compared with no activity for the free drug. Improving the therapeutic index of anticancer drugs by combining tumour tropism with decreased systemic toxicity is a versatile approach that should produce a new generation of improved anticancer agents.     

Risk factors in the development of ocular surface epithelial dysplasia

BACKGROUND: Ocular surface epithelial dysplasia involves a spectrum of diseases ranging from only minor eye irritation to blindness and potentially death. METHODS: A case-control study involving 60 patients with ocular surface epithelial dysplasia treated between 1972 and 1991 and 60 age- and sex-matched individuals was conducted to compare relative ultraviolet light exposures over their lifetimes. A standardized self-administered ultraviolet exposure questionnaire was used for assessment. RESULTS: Risk factors identified include phenotypic features such as fair skin (odds ratio [OR], 5.4; 95% confidence interval [CI], 1.1, 25.6), pale iris (OR, 1.8; 95%; CI, 0.9, 3.8), and propensity to sunburn (OR, 3.8; 95% CI, 0.7, 19.7), history of previous skin cancers removed (OR, 15; 95% CI, 2.0, 113.6), and being outdoors more than 50% of time in the first 6 years of life while living 30 degrees or less from the equator (OR, 7.5; 95% CI, 1.8, 30.6). CONCLUSION: These risk factors suggest that ocular surface epithelial dysplasia is an ultraviolet light-related disease.     

The use of meditation--relaxation techniques for the management of stress in a working population

The efficacy of meditation-relaxation techniques has been widely researched in the laboratory, but their effectiveness for management of stress in organizational settings is still relatively unexplored. The present study compared relaxation and control conditions as part of a program of stress-reduction in industry. A total of 154 New York Telephone employees self-selected for stress learned one of three techniques--clinically standardized meditation (CSM), respiratory one method meditation (ROM) or progressive relaxation (PMR)--or served as waiting list controls. At 5.5 months, the treatment groups showed clinical improvement in self-reported symptoms of stress, but only the meditation groups (not the PMR group) showed significantly more symptom reduction than the controls. The meditation groups had a 78% compliance rate at 5.5 months with treatment effect seen whether subjects practiced their techniques frequently or occasionally. The safe and inexpensive semi-automated meditation training has considerable value for stress-management programs in organizational settings.     

Sliding conjunctival flap for the treatment of primary pterygium

BACKGROUND: The major problems after pterygium removal are recurrence and complications of the therapy. The authors investigated a simple surgical treatment without adjunctive therapy for primary pterygium. METHODS: Patients eligible to be included in the study were identified from a pterygium treatment log. They represent consecutive cases over a 6 1/2-year period, all of whom had been treated by one surgeon using a superior, sliding, conjunctival flap to cover the pterygium defect. An attempt was made to obtain follow-up of at least 1 year for each patient. RESULTS: Two hundred fifty-eight eyes in 236 patients were included in the study. Two hundred twenty-two eyes (86%) were able to be followed by either record review or re-examination. Seven pterygia (3.2%) recurred, all identified by record review, with no recurrences identified by re-examination. Recurrences were more likely after early postoperative flap retraction (5 of 7 recurrences) and recurrence occurred at a mean interval of 4.3 months (range, 1.5-11 months) after surgery. Symptomatically, the patients were comfortable, and the cosmetic result was good. CONCLUSION: This study indicates that this simple surgical procedure for the treatment of primary pterygium should be evaluated further by controlled clinical trials.     

Efficacy and safety of inhaled Salmeterol (Serevent) as maintenance therapy for asthma in Nairobi

An open study to assess the efficacy and safety of 50 micrograms inhaled Salmeterol (Serevent) administered twice daily as maintenance therapy for asthma was undertaken by the Respiratory Diseases Research Unit (RDRU) in Nairobi between August and October, 1992. Salmeterol (Hydroxynaphthoate) is a long acting selective beta-2-agonist. Seventy-three adult patients recruited at Kenyatta National Hospital underwent a two weeks treatment period during which they were assessed over three visits. At Visit 1, eligibility was confirmed, baseline lung function indices measured, the study drug introduced and all the previous medications withdrawn. After treatment for one week (Visit 2) and two weeks (Visit 3), lung function indices were measured again and subjective patients' and physicians' assessments of efficacy documented. Patients with obstructive ventilatory defect (OVD) at baseline had significant improvement in their lung function compared to those without at the end of the treatment period. A significant number of patients reported decreased number of nocturnal awakenings and increased tolerance to physical activity. Cough, headache and itchy throat were adverse events possibly related to the use of Salmeterol. The patients treated with Salmeterol gained improved control of their asthma symptoms. The drug offers a convenient dose schedule and we recommend its use for maintenance therapy for mild to moderate asthma.     

Pharmacokinetics, oral bioavailability, and metabolism in mice and cynomolgus monkeys of (2'R,5'S-)-cis-5-fluoro-1-[2-(hydroxymethyl)-1,3-oxathiolan-5-yl] cytosine, an agent active against human immunodeficiency virus and human hepatitis B virus

(2'R,5'S-)-cis-5-Fluoro-1-[2-(hydroxymethyl)-1,3-oxathiolan-5-yl] cytosine (524W91) is a nucleoside analog with potent anti-human immunodeficiency virus and anti-human hepatitis B virus activities in vitro. The pharmacokinetics and bioavailability of 524W91 after oral dosing were studied in mice dosed with 10, 100, and 600 mg of 524W91 per kg of body weight by the oral and intravenous routes. Cynomolgus monkeys were dosed with 10 and 80 mg of 524W91 per kg. In both species, the clearance of 524W91 was rapid, via the kidney, and was independent of dose. In monkeys, the total body clearance of 10 mg of 524W91 per kg was 0.7 +/- 0.1 liter/h/kg, and the volume of distribution at steady state was 0.8 +/- 0.02 liter/kg. The terminal elimination half-life was 1.0 +/- 0.2 h. The absolute bioavailability after oral dosing was 63% +/- 4% at 10 mg/kg. Concentrations of 524W91 in the cerebrospinal fluid were 4% +/- 0.7% of the corresponding levels in plasma. In mice, the total clearance of 10 mg of 524W91 per kg was 2.3 liters/kg/h, and the volume of distribution at steady state was 0.9 liter/kg. Absolute bioavailability in mice after oral dosing was 96% at a dose of 10 mg/kg. The metabolism of orally administered [6-3H]524W91 was studied in cynomolgus monkeys at a dose of 80 mg/kg and in mice at a dose of 120 mg/kg. Monkeys excreted 41% +/- 6% of the radioactive dose in the 0- to 72-h urine, 33% +/- 10% in the feces, and 10% +/- 7% in the cage wash. Unchanged 524W91 was 64% of the total radiolabeled drug recovered in the urine. The glucuronide was a minor urinary metabolite. 5-Fluorouracil was not detected (less than 0.02% of the dose). Mice dosed orally with 120 mg of [6-3H]524W91 per kg excreted 67% +/- 7% of the radiolable in the )- to 48-h urine. Small amounts of the 3' -sulfoxide and glucuronide metabolites were observed in the urine, but 5-fluorouracil was not detected. Good bioavailability after oral dosing and resistance to metabolism recommend 524W91 for further preclinical evaluation.