Effects of Zinc and N-Acetylcysteine in Damage Caused by Lead Exposure in Young Rats

This study investigated the toxicity of rats exposed to lead acetate (AcPb) during the second phase of brain development (8-12 days postnatal) in hematological and cerebral parameters. Moreover, the preventive effect of zinc chloride (ZnCl₂) and N-acetylcysteine (NAC) was investigated. Pups were injected subcutaneously with saline (0.9% NaCl solution), ZnCl₂ (27 mg/kg/day), NAC (5 mg/kg/day) or ZnCl₂ plus NAC for 5 days (3rd-7th postnatal days), and with saline (0.9% NaCl solution) or AcPb (7 mg/kg/day) in the five subsequent days (8th-12th postnatal days). Animals were sacrificed 21 days after the last AcPb exposure. Pups exposed to AcPb presented inhibition of blood porphobilinogen-synthase (PBG-synthase) activity without changes in hemoglobin content. ZnCl₂ pre-exposure partially prevented PBG-synthase inhibition. Regarding neurotoxicity biomarkers, animals exposed to AcPb presented a decrease in cerebrum acetylcholinesterase (AChE) activity and an increase in Pb accumulation in blood and cerebrum. These changes were prevented by pre-treatment with ZnCl₂, NAC, and ZnCl₂ plus NAC. AcPb exposure caused no alteration in behavioral tasks. In short, results show that AcPb inhibited the activity of two important enzymatic biomarkers up to 21 days after the end of the exposure. Moreover, ZnCl₂ and NAC prevented the alterations induced by AcPb.

Relation of cervical length at 22-24 weeks of gestation to demographic characteristics and obstetric history

Preterm delivery is the main cause of neonatal death and ultrasonographic cervical assessment has been shown to be more accurate than digital examination in recognizing a short cervix. This is a cross-sectional study, involving 1131 women at 22-24 weeks of pregnancy, designed to determine the distribution of cervical length and to examine which variables of demographic characteristics and obstetric history increase the risk of a short cervix (15 mm or less). The distribution of maternal demographic and obstetric history characteristics among patients with cervical length pound 15 mm was analyzed and compared to the findings for the general population. Risk ratios (RR) between subgroups were generated from this comparison. Median cervical length was 37 mm and in 1.5% of cases it was 15 mm or less. The proportion of women with a short cervix (< or =15 mm) was significantly higher among patients with a low body mass index (RR = 3.5) and in those with previous fetal losses between 16-23 weeks (RR = 33.1) or spontaneous preterm deliveries between 24-32 weeks (RR = 14.1). We suggest that transvaginal sonographic measurement of cervical length be performed as part of a routine midtrimester ultrasound evaluation. There are specific variables of demographic characteristics and obstetric history which increase the risk of detecting a short cervix at 22-24 weeks.

Comparison between the Comfort and Hartwig sedation scales in pediatric patients undergoing mechanical lung ventilation

CONTEXT

A high number of hospitalized children do not receive adequate sedation due to inadequate evaluation and use of such agents. With the increase in knowledge of sedation and analgesia in recent years, concern has also risen, such that it is now not acceptable that incorrect evaluations of the state of children's pain and anxiety are made.

OBJECTIVE

A comparison between the Comfort and Hartwig sedation scales in pediatric patients undergoing mechanical lung ventilation.

DESIGN

Prospective cohort study.

SETTING

A pediatric intensive care unit with three beds at an urban teaching hospital.

PATIENTS

Thirty simultaneous and independent observations were conducted by specialists on 18 patients studied.

DIAGNOSTIC TEST

Comfort and Hartwig scales were applied, after 3 minutes of observation.

MAIN MEASUREMENTS

Agreement rate (kappa).

RESULTS

On the Comfort scale, the averages for adequately sedated, insufficiently sedated, and over-sedated were 20.28 (SD 2.78), 27.5 (SD 0.70), and 15.1 (SD 1.10), respectively, whereas on the Hartwig scale, the averages for adequately sedated, insufficiently sedated, and over-sedated were 16.35 (SD 0.77), 20.85 (SD 1.57), and 13.0 (SD 0.89), respectively. The observed agreement rate was 63% (p = 0.006) and the expected agreement rate was 44% with a Kappa coefficient of 0.345238 (z = 2.49).

CONCLUSIONS

In our study there was no statistically significant difference whether the more complex Comfort scale was applied (8 physiological and behavioral parameters) or the less complex Hartwig scale (5 behavioral parameters) was applied to assess the sedation of mechanically ventilated pediatric patients.

[Incipient cariogenic demineralization of human enamel]

32 teeth (12 premolars and 20 molars) were studied under light microscopy, polarized microscopy, transparence light microscopy and scanning electron microscopy. These teeth presented changes in colour in their free and proximal surface as well as close to pits and fissures. As an extra diagnostic test the PAS reaction was used to assess descalcifying processes in both light and transparence microscopy. Polarized light was used to assess normal enamel. Scanning electron microscopy corroborated the lesions produced in the enamel surface in the form of micropores. PAS reaction diagnosed decalcifying processes in yellow, brown and brownish stains. White staims not always were PAS-positive and when they reacted in the same manner as other positive stains, with the immersion technique. This penetrated 40-60 umtrs. and in some areas in relation to lamellae they reached dentin. Light, polarized and scanning electron microscopy showed the presence of micropores in the external surface of enamel in PAS-positive cases. The possibility of a modified PAS technique to use in clinical practice is discussed. It is concluded that PAS relation is useful as "ex situ" test to detect the first signs of mineral salt loss at the enamel surface. More research is needed to transfer these results to clinical practice.

[Experimental sialadenitis in castrated rats administered estrogens]

Salivary glands are dependent on sexual hormones. The aim of the present work is to study the behavior of inflammatory response induced in animals that were castrated and injected with estrogens. Male adult wistar castrated rats (60-90 days) were used. A phlogogen pellet (zinc-oxide-turpentine essence) was placed between their sublingual and submaxillary glands and they were daily injected with 5 units of estrogen. The rats were killed after 8 and 12 days of treatment; submandibular pack was weighed, dissected and fixed in phormol Ph7 for its morphohistochemical study. Phlogogen pellet breaks out an acute inflammatory response that appears attenuated in castrated animals. Such character is enhanced when estrogens are used, disappearing ductal ectasis, becoming evident a granulation tissue of strange body in phagocytic activity and in contact with the pellet. As a consequence its follows that estrogen administration in castrated animals attenuates acute inflammatory response broken out by phlogogen pellet, determining characters with tendency to chronicity and giant cells differentiation of strange body.

Histochemistry of glycoconjugates of pleomorphic adenomas of minor salivary glands, with special reference to glycocalyx of tubular areas

Histochemical characterization of glycoconjugates elaborated by palatal pleomorphic adenomas showed that glycoproteins, glycosaminoglycans, and perhaps glycolipids were present in both the "epithelial" and "connective tissue" components of these tumors, as well as in the distinct glycocalyx present in the luminal surface of tubular and cystic areas.