Clinical effectiveness of lidocaine and benzocaine for topical anesthesia

The effectiveness of lidocaine and benzocaine in reducing pain produced by needle insertion into the palate was evaluated in a double-blind and placebo-controlled study using a more suitable method. Twenty subjects, 10 men and 10 women, submitted to 4 sessions in which they were randomly treated with 5% lidocaine, a placebo that tasted like lidocaine, 20% benzocaine, and a placebo that tasted like benzocaine. At each session, a 27-gauge needle was inserted into the palate twice, once before (baseline) and once after drug application for 1 minute. Immediately after each insertion, subjects indicated on a visual analog scale the pain intensity perceived. Lidocaine and benzocaine were equally efficient, and both were better than placebo in reducing pain caused by insertion of needles into the palate.

Oral administration of sodium selenite minimizes cisplatin toxicity on proximal tubules of rats

Cisplatin (c-DDP) is a widely used antineoplastic drug whose main side effect is nephrotoxicity. Selenium, administered intravenously or intraperitoneally, has been shown to provided protection against c-DDP-induced nephrotoxicity in rats. In the present study, the protective effect of orally administered sodium selenite on c-DDP toxicity was further examined. Animals treated with c-DDP alone showed increased urinary volume, decreased creatinine clearance (GFR), and a rise in urinary N-acetyl-(beta-D-glucosaminidase) (NAG) isoenzyme B activity. When sodium selenite was given prior to c-DDP, rats showed less GFR decline, delayed urinary volume increases, and no urinary NAG isoenzyme B activity increment. It is suggested that a single oral dose of sodium selenite given prior to c-DDP administration, although not preventing deterioration of renal function, partially protects rats from early proximal tubular injury.

[Occupational risk of acquiring tuberculosis among hospital nursing personnel]

At hospitals, patients with tuberculosis are attended by several professionals and among them nursing workers. These workers are subjected to the risk of the tuberculosis infection. This study had the objective of investigating the number of nursing workers in a hospital that acquired tuberculosis in a pre-determined period and their general characteristics; to calculate the morbidity coefficient of this disease and discuss the occupational risk among these workers. In one year, health workers presented 3.86 times greater risk, and, in another year, 1.47 times greater risk. In the present study tuberculosis was considered an occupational hazard for hospital nursing workers.

Effect of oral selenium administration on cisplatin-induced nephrotoxicity in rats

Cis -diamminedichloroplatinum(II) (CP), an important antineoplasic drug, shows remarkable toxicity to the kidney. Methods to reduce CP nephrotoxicity include the use of sodium selenite. The aim of the present study was to investigate the interaction between orally administered selenium and CP in the rat. After observing the effects of CP on body growth rate, urinary volume, serum creatinine, serum selenium levels, creatinine clearance, renal malondialdehyde, and glutathione levels, as well as on renal light microscopically visible lesions, the effects of the sodium selenite administration by gavage of 2 mg per kg of body wt. 24 h and 1 h prior to a single CP intraperitoneal injection of 5 mg per kg of body wt. followed by its daily administration for the 7 subsequent days on these parameters, were examined. CP increased renal malondialdehyde, renal glutathione, and serum creatinine and decreased creatinine clearance. Lipid peroxidation is one of the mechanisms by which CP induces renal damage. Selenium treatment decreased the effect of CP on serum creatinine, and renal malondialdehyde levels, but did not affect the other parameters with the exception of kidney necrosis which was also diminished by this treatment.

Inhibition of the lethal and myotoxic activities of Crotalus durissus terrificus venom by Tabernaemontana catharinensis: identification of one of the active components

In Brazilian folk medicine, victims of bites by poisonous animals are usually treated with plant extracts derived from the diverse national flora. The chemical and pharmacological properties of most extracts were yet not investigated. In the rural community of Assis-SP, the root bark of Tabernaemontana catharinensis ("leiteiro", "cow milk") is applied to the site of the snake bite and believed to neutralize the effect of the venom. We report here the ability of the lyophilized aqueous extract (AE) and of a pure compound obtained from the ethanolic extract of T. catharinensis to inhibit the lethal and myotoxic activities of C. d. terrificus (South American rattlesnake) venom. Doses of 10 mg AE/100 g, injected (i.m., rat) 20 s after injecting (i.m.) the venom and that of 2.5 mg AE/100 g, incubated for 1 h at 25 degrees C with the venom before injection (i.m.) were able to neutralize the lethal activity of 2LD50. These data indicate that T. catharinensis could be used as a source of a model molecule able to neutralize the lethality and myotoxicity induced by C. d. terrificus venom. Its ethanolic extract was then fractionated on a silica gel 60 chromatography column affording fractions A to F. Fraction A consisted basically of non-polar compounds, terpenes and sterols. Fraction D showed a pronounced antiophidian activity which was later correlated with the presence of the quaternary alkaloid 12-methoxy-4-methylvoachalotine in this fraction. This alkaloid was isolated and inhibited 100% lethality when injected 20 s after 2 LD50 at 1.7 mg/100 g.

[Chemical substances, work and neurologic changes: possible relationships between those variables]

Authors searched 239 reports of patients admitted in a hospital who carried neurological pathologies with unknown etiologies in order to find the possible relationship between the disease and the occupational use of chemical substances. They found the occupation in 32 reports. 37.50% of the patients worked with agriculture; 34.37% were maids/worked at home; 12.50% were masons; one was a shoemaker, one a saddler; one made furniture and the others worked with machines. Considering their activities, they possibly used chemical substances. Few information relating this utilization and the presented disease showed the reduced importance given to these variables.

Radiographic contrast. A comparative study of three dental X-ray films

OBJECTIVE

To investigate the radiographic contrast of three dental X-ray films (Ultra-speed, Ektaspeed and Ektaspeed Plus, Eastman-Kodak, Rochester, NY, USA).

METHODS

An aluminium stepwedge was radiographed for the objective assessment and a dried human mandibular segment including the teeth for the subjective evaluation. In the objective assessment, contrast was evaluated from the measured optic densities and the results analysed statistically by the Kruskal-Wallis one-way Anova and Mann-Whitney U test. Subjective evaluation was performed by 12 dentists with a range of clinical experience and scores were assigned to five dental and bony structures.

RESULTS

In the objective evaluation there was no significant difference in contrast obtained with the Ultra-speed and Ektaspeed Plus films: both had significantly better contrast than Ektaspeed film. The subjective assessment revealed that the majority of the dentists preferred either Ultra-speed or Ektaspeed Plus films for contrast.

CONCLUSION

Radiographic contrast of Ektaspeed Plus did not differ significantly from Ultra-speed and both were superior to Ektaspeed film.

[Speculation on the rate of diphtheria infection in a simple stochastic epidemic model]

Com base em um programa em linguagem Fortran, utilizando a técnica de simulação em computador e através das pressuposições do Modelo Estocástico Simples de Epidemia, é estabelecida uma conjectura a respeito de valores para a taxa de infecção para a difteria, a partir de ocorrência de casos em um domicílio de cinco pessoas.