Inhibition of 2-nitropropane-induced rat liver DNA and RNA damage by benzyl selenocyanate

We observed that pretreatment of male F344 rats with benzyl selenocyanate, a versatile organoselenium chemopreventive agent in several animal model systems, decreases the levels of DNA and RNA modifications produced in the liver by the hepatocarcinogen 2- nitropropane. To clarify the mechanisms involved, we pretreated male F344 rats with either benzyl selenocyanate, its sulfur analog benzyl thiocyanate, phenobarbital or cobalt protoporphyrin IX; the latter is a depletor of P450. We then determined (1) the ability of liver microsomes to denitrify 2-nitropropane, (2) effects on 2-nitropropane- induced liver DNA and RNA modifications and (3) amount of nitrate excreted in rat urine following administration of the carcinogen. Pretreatment with benzyl selenocyanate or phenobarbital increased the denitrification activity of liver microsomes by 217 and 765%, respectively, increased liver P4502B1 by 31- and 435-fold, respectively, decreased the levels of 2-nitropropane-induced modifications in liver DNA (29-70% and 17-30%, respectively) and RNA (67-85% and 30-50%, respectively), and increased the 24-h urinary excretion of nitrate by 157 and 209%, respectively. Pretreatment with benzyl thiocyanate had no significant effect on any of these parameters. Pretreatment with cobalt protoporphyrin IX decreased liver P4502B 1 by 87%, decreased the denitrification activity of liver microsomes by 76%, decreased the 24 h urinary excretion of nitrate by 88.5%, but increased the extent of 2-nitropropane-induced liver nucleic acid modifications by 17-67%. These results indicate that the metabolic sequence from 2-nitropropane to the reactive species causing DNA and RNA modifications does not involve the removal of the nitro group. Moreover, they suggest that benzyl selenocyanate inhibits 2-NP-induced liver nucleic acid modifications in part by increasing its detoxication through induction of denitrification, although it is evident that other mechanisms must also be involved.      

The effect of intravenous immunoglobulin on the in vitro function of human neutrophils

Three commercially available preparations of human immunoglobulin for intravenous use (IVIgG), namely Gamimune N. Sandoglobulin and Intraglobin F, were tested for their ability to modulate human neutrophil function in vitro. IVIgG consistently stimulated the neutrophil respiratory burst at concentrations of 0.5 to 1 mg/ml, concentrations readily achieved in vivo by moderate-dose therapy. Superoxide (O2-) release was increased by 3.5-4.5 nmol per 5 x 10(5) cells at these concentrations of IVIgG, and H2O2 production increased in a dose-dependent fashion up to 8 mg/ml IVIgG. Luminol-dependent chemiluminescence (CL) was also directly stimulated by IVIgG. In addition, the effects of both soluble and particulate stimulators (N-formyl-methionyl-leucyl-phenylalanine, phorbol myristate acetate and opsonized zymosan) on the neutrophil respiratory burst were enhanced by IVIgG. In a filter assay of neutrophil migration, using a modified Boyden chamber, no consistent effect on neutrophil locomotion or chemotaxis could be demonstrated. The effect of IVIgG on neutrophil metabolism may contribute to its beneficial therapeutic effect in severe, life-threatening infections.     

Microbehavioral approaches to monitoring human experience

Microbehavioral approaches to social science research minimize the complexities of general activity reporting by limiting questions to elementary activity experience in the context of daily life. Time diaries and sampling studies of activity at random moments during the day are two examples of this approach.     

Electronic and disposable patient-controlled analgesia systems

We have compared the performance of the Baxter disposable with the Graseby electronic patient-controlled analgesia system in 30 patients following major gynaecological surgery. Patients were allocated randomly to receive analgesia via the Baxter or Graseby device for postoperative pain relief. There were no significant differences between the two groups with regard to postoperative pain relief or sedation as measured by visual analogue scale. Requirements for antiemetic drugs and patient acceptability were similar. Mean (SEM) morphine demanded over 30 h was 35.7 (6.6) in the Graseby group and 35.1 (8.5) in the Baxter group.     

Impact of a shielded safety syringe on needlestick injuries among healthcare workers.

OBJECTIVES: Evaluate the impact of a shielded 3 cc safety syringe on needlestick injuries among healthcare workers. DESIGN: Surveillance study. SETTING: Three medical centers. RESULTS: The total number of needlesticks from all sources rose from 134 during the baseline period to 140 during the study phase. However, the overall rate of needlesticks involving 3 cc syringes decreased from 14/100,000 inventory units to 2/100,000, and the frequency declined substantially at each of the participating medical centers. CONCLUSIONS: These results suggest that shielded syringes and related technology may offer potential for reducing the risk of needlestick injuries among hospital and other healthcare employees. This study should be viewed as a preliminary effort to assess the potential of shielded-syringe technology for reducing the risk of needlestick injuries among healthcare workers. The results are encouraging, but more clinical experience with this new device and longer follow up are essential to provide the data necessary for a definitive assessment of efficacy.     

Partial resolution of acute interstitial pneumonia in native lung after single lung transplantation.

The case of a 49 year old man presenting with rapidly progressive interstitial lung disease is described. Radiological findings and the lung biopsy specimen were compatible with an acute interstitial pneumonia, as was the relentless clinical course culminating in hypoxic respiratory failure. After right single lung transplantation there was considerable improvement in lung function and radiographic clearing of disease in the native left lung.