Evaluation of three substitutes for Percoll in sperm isolation by density gradient centrifugation

Silane-coated silica particle solutions (ISolate(TM) and PureSperm)TM)) and iodixanol (OptiPrep(TM)) were compared to polyvinylpyrrolidone (PVP)-coated silica particles (Percoll(TM)) in their efficacy to recover spermatozoa by gradient centrifugation for use in assisted reproductive procedures. Efficacy was assessed in terms of percentages of sperm recovery, sperm vitality and motility, normal sperm morphology and normal sperm chromatin condensation. No significant difference was found in the recovery of spermatozoa for men with both normal sperm counts and oligozoospermia, between PVP-coated and silane-coated particle solutions. Iodixanol had significantly lower sperm recovery compared to the other products. Sperm vitality, progressive motility, normal morphology and normal chromatin condensation did not differ significantly between any of the sperm isolation products.      

Protective cytotoxic T lymphocyte responses against paramyxoviruses induced by epitope-based DNA vaccines: involvement of IFN-gamma

Plasmid DNA vectors have been constructed with minigenes encoding a single cytotoxic T lymphocyte (CTL) epitope from either the M2 protein of respiratory syncytial virus (RSV) or from the nucleoprotein of measles virus (MV) with or without a signal sequence (also called secretory or leader sequence). Following intradermal immunization, plasmids in which the CTL epitopes were expressed in-frame with the signal sequence were more effective at inducing peptide- and virus- specific CTL responses than plasmids expressing CTL epitopes without the signal sequence. This immunization resulted in protection against MV-induced encephalitis and a significant reduction in viral load following RSV challenge. The reduction of viral load following RSV challenge was abrogated by prior injection with anti-IFN-gamma antibodies. These results highlight the ability of epitope-based DNA immunization to induce protective immune responses to well-defined epitopes and indicate the potential of this approach for the development of vaccines against infectious diseases.      

Charcoal and Rifampicin Pharmacokinetics

We investigated the effect of activated charcoal on rifampicin disposition in six healthy subjects. On three occasions (control, phases II and III, separated by 1 week), each subject received 600 mg of rifampicin with 350 ml of water. On the second and third occasions (phases II and III), each subject received in addition to 600 mg of rifampicin and 7.5 and 15 g of activated charcoal, respectively, in 350 ml of water as charcoal slurry. Plasma rifampicin levels were measured from 1 to 24 h postrifampicin ingestion. Treatment with activated charcoal significantly increased the clearance and decreased the maximum peak concentration, half-lives and area under the curves as compared with control treatment without activated charcoal.     

Anicteric hepatoxicity: a potential health risk of occupational exposures in Nigerian petroleum oil refining and distribution industry

Background

Literature abounds linking one’s job to certain unpalatable health outcomes. Since exposures to hazardous conditions in industrial environments often results in sundry health effects among workers, we embarked on this study to investigate the hepatic health effects of occupational activities in the petroleum refining and distribution industry.

Method

Biochemical markers of liver functions were assayed in plasma, using Reflotron dry chemistry spectrophotometric system. The study was conducted on randomly selected workers of Port Harcourt Refining Company (PHRC) and Pipelines and Petroleum Product Marketing Company (PPMC) both in Alesa-Eleme near Port Harcourt, Nigeria, as well as non-oil work civil servants serving as control subjects.

Result and conclusion

Results showed that, bilirubin ranged 0.3-1.6 mg/dl with a mean of 0.66±0.20mg/dl among the oil workers as against 0.5-1.00mg/dl with a mean of 0.58±0.13mg/dl in non-oil workers, Alkaline phosphatase ranged 50.00-296.00u/l (mean: 126.21±39.49u/l) in oil workers as against 40.20-111u/l (mean: 66.83±18.54u/l) for non-oil workers, Aspartic transaminases (AST) ranged 5.80-140.20u/l (mean: 21.81±11.49u/l) in oil workers against 18.00-44.00u/l (mean: 26.89±6.99u/l) for non-oil workers, while Alanine transaminases (ALT) ranged 4.90-86.00u/l (mean: 22.14±11.28u/l) in oil workers as against 10.00-86.60u/l (mean: 22.30±10.22u/l) for the non-oil workers. A close study of the results revealed that although the mean values for all the studied parameters were still within the parametric reference ranges, however, relative to the referents, there were significant increases (P<0.05) in plasma bilirubin (though anicteric) and alkaline phosphatase that was not matched with a corresponding increase in the plasma transaminases, suggesting a possibility that toxic anicteric hepatoxicity is part of the potential health effects of sundry exposures in the Nigeria petroleum oil refining and distribution industry. Gender differentiation data showed that though the mean values for the parameters were higher in males than females, the increases were not significant in most cases (P>0.05), whereas data for age and exposure period classifications revealed that irrespective of the age of the worker, the effects are likely to start after the first five years, manifesting fully after the first decade of occupational exposures. Thus, an update of industrial/occupational health measures is necessary for a safer and healthier work environment.     

Analysis of the relationship between age and treatment response in migraine

In migraine, headache severity varies with age. As a consequence, the effectiveness of medication may also depend on a patient's age. The purpose of this study was to assess the combined effect of age and drug treatment on headache characteristics. Using data from clinical trials of sumatriptan in adolescents and adults, we show how the interaction between age and drug exposure can be parameterised as a covariate on a Markov model that describes the decline of headache severity over three clinically defined stages (no relief, relief and pain-free status). The model explains important clinical observations: (i) the rates at which the pain relief and pain-free status were attained were found to be inversely related to age; (ii) in placebo-treated patients, the mean transit time from 'no relief' to 'relief' is 3 h for young adolescents and increases to 6 h for patients aged ≥ 30 years; and (iii) sumatriptan reduces the transit time to 2 h, irrespective of age. These findings indicate that the therapeutic gain over placebo increases with age. Prospective studies of antimigraine drugs should take this relationship into account when extrapolating efficacy data from adults to adolescents.     

Childhood non-drug poisoning in Nnewi, Nigeria

While poisonings from developed nations have been extensively described there is a dearth of information on poisoning in societies which have different patterns of daily life, customs, products and beliefs. This study surveys childhood non-drug poisoning, the circumstances of exposure, prevalence demographics and products as well as therapy.The commonest poisoning is kerosene (paraffin), incidence was 2/1000 and the age at highest risk is 12-24 months. Often cases were inappropriately managed at home before arriving at the hospital.     

Zinc protection of mercury-induced hepatic toxicity in mice

The actions and interactions of heavy metals on certain organ functions have been of concern, since occupational exposure to certain metals results in impairment of functions. Studies were carried out to determine the effects of zinc (Zn) and mercury (Hg) on murine liver. CD-1 male mice were administered 4 ppm HgCl2, 800 ppm ZnCl2, 4 ppm HgCl2+800 ppm ZnCl2 or deionized water in their drinking water for 12 weeks. Histological evaluation of the liver confirmed the toxic effects of Hg, as well as the normal morphology of the Zn-exposed animals. A combined treatment of both metals resulted in protection of the Hg-induced liver damage by Zn. The results of this experiment indicate that Hg has a toxic effect on liver, while Zn has a protective action against such toxic effects.     

Structural development, haematological immunological and pharmacological effects of quinolones

The interest of the medical community in quinolones has not decreased despite more than ten years of continuous and growing use of these agents. The constant need for new anti microbials has produced a variety of newer quinolones termed as I, II, III, and IV generation. Nalidixic acid and other early quinolones had limited use due to poor pharmacokinetics, relatively narrow antimicrobial spectrum of activity, and frequent adverse effects. Extensive pharmacologic and clinical development of quinolone antimicrobial agents has resulted in improved antimicrobial activity, pharmacokinetic features, toxicity, and drug-drug interaction profiles. These attributes, coupled with their expanded spectrum and the immune enhancing phenomena of quinolones with a cyclopropyl moiety at position 1 of the quinolone ring suggest that the newer fluoroquinolones are so far the most ideal agents for the empirical treatment of many common infections. The above has made it desirable to review the status of these agents as revealed in published literature. The thrust of this review is on the structural development, pharmacological, haematological and immunological effects of quinolones. Recent patents filed are also discussed.     

A randomized double-blind placebo-controlled crossover study of subcutaneous sumatriptan in general practice

Objective. To evaluate the therapeutic response to sumatriptan in the acute migraine attack. Material and methods. Two hundred and thirty migraineurs diagnosed by their general practitioners in accordance with their usual practice were included in the study. The patients treated two migraine attacks at home by subcutaneous injection of sumatriptan or placebo for the first attack and the alternative medication, i.e. placebo or sumatriptan, for the second attack (crossover). Following treatment, a neurology resident interviewed and examined the patients, Results. When sumatriptan was compared to placebo, significantly more of the 209 evaluable patients reported headache relief at I h (56% vs 8%, p < 0.001) and 2 h (62% vs 15%, p < 0.001) after the first injection. Resolution of nausea, photophobia, and phonophobia was significantly more common in patients on sumatriptan than in those on placebo ( p < 0.001 for all comparisons). The adverse events were usually transient and of mild or moderate severity; however, three patients withdrew due to adverse events. Ninety-five percent of patients evaluated by a neurology resident met the IHS criteria for migraine. Conclusion. In general practice, sumatriptan taken subcutaneously using an autoinjector at home was an effective and well tolerated acute treatment for migraine.     

Calcium transport and ultrastructure of red cells in beta-thalassemia intermedia

Reported findings of elevated total calcium (Ca) contents in erythrocytes (RBCs) from patients with beta-thalassemia intermedia (beta-TI) prompted the question of whether the state and transport of Ca in these RBCs are similar to those in sickle cell anemia (SS) RBCs where the increased Ca is compartmentalized in endocytic inside-out vesicles and extracted by exposure of the cells to the Ca ionophore A23187 and a Ca chelator (ethylene glycol tetraacetic acid) and the levels of cytoplasmic free ionized Ca [( Ca2+]i) are normal. We confirmed a high total Ca content of 51 +/- 13 mumol/L RBCs in splenectomized (SPX) beta-TI and 24 +/- 1 mumol/L RBCs in non-SPX beta- TI. Unlike SS RBCs, however, most of the increased Ca was in the lighter, presumably younger beta-TI RBCs, and about half the Ca was not ionophore mobilizable but apparently firmly bound, possibly to remnants of organelles in nucleated and other young RBCs. In the denser RBCs from non-SPX beta-TI, total and extractable Ca amounts were normal. beta-TI RBCs loaded with the Ca chelator Benz 2 showed an initial influx of 45Ca in the normal range, which indicated normal Ca permeability, and near-steady-state levels of [Ca2+]i that were normal (22 +/- 7 nmol/L RBCs in non-SPX beta-TI) or minimally increased (40 +/- 19 nmol/L RBCs in SPX beta-TI). Serial-section electron microscopy of beta-TI ghosts from the denser cell fractions showed more fully enclosed vesicles in non-SPX ghosts than were seen in normal ghosts and many large vesicles and structured, electron-dense material in SPX ghosts. A delayed extrusion of ionophore-preloaded 45Ca only by the SPX beta-TI RBCs together with normal [Ca2+]i suggested compartmentalization of the loaded Ca in these RBCs, perhaps in endocytic inside-out vesicles, and normal Ca pumps. Since beta-TI RBCs show essentially normal levels of [Ca2+]i and normal Ca influx, their high total Ca content should not be associated with any of the deleterious effects observed in vitro with increased levels of [Ca2+]i.