The effects of literacy and education on the quantitative and qualitative aspects of semantic verbal fluency.

Semantic verbal fluency tasks are commonly used in neuropsychological assessment. Investigations of the influence of level of literacy have not yielded consistent results in the literature. This prompted us to investigate the ecological relevance of task specifics, in particular, the choice of semantic criteria used. Two groups of literate and illiterate subjects were compared on two verbal fluency tasks using different semantic criteria. The performance on a food criterion (supermarket fluency task), considered more ecologically relevant for the two literacy groups, and an animal criterion (animal fluency task) were compared. The data were analysed using both quantitative and qualitative measures. The quantitative analysis indicated that the two literacy groups performed equally well on the supermarket fluency task. In contrast, results differed significantly during the animal fluency task. The qualitative analyses indicated differences between groups related to the strategies used, especially with respect to the animal fluency task. The overall results suggest that there is not a substantial difference between literate and illiterate subjects related to the fundamental workings of semantic memory. However, there is indication that the content of semantic memory reflects differences in shared cultural background--in other words, formal education--, as indicated by the significant interaction between level of literacy and semantic criterion.     

Evaluation of Class I ART restorations in Brazilian schoolchildren: three-year results

Atraumetic Restorative Treatment (ART) has been adopted around the world to avoid unnecessary extractions, especially in non-industrialized countries The development of specific glass ionomer cements marketed for the ART technique has contributed to the technical success rate. In this study. Ketac-Molar^a (3M ESPE. Dental Medzn Germany) was used to restore 150 Class I cavities in 118 Brazilian public school children, aged from 7–12 years. At baseline and at subsequent recalls. CPI probes with a ball-end of 0.5 millimeters (mm) were used to assess loss of restorative material, and photographic color transparencies of restorations were made. After six months. 83 patients returned for follow-up examinations, with 71.8% of their restorations designated as acceptable. After three years. 49 patients with 57 ART-restorations were evaluated, with 21.0% of these restorations graded as acceptable Another 29.8% of their restorations had been replaced by more permanent materials. The main objective of the ART technique is tooth retention; this was achieved for 94.7% of the restored teeth in a high caries risk population who returned for recalls.     

Effects of rufloxacin in Salmonella typhimurium infection in mice.

This study was undertaken to investigate the efficacy of rufloxacin, a new quinolone which is interesting due to its pharmacokinetics characterized by a long plasma half-life, in the treatment of systemic salmonella infections in the mouse typhoid model. Innately susceptible BALB/c and resistant CBA mice were used to investigate the efficacy of rufloxacin in controlling systemic salmonella infections when given for brief or prolonged periods. The present study shows that rufloxacin is not only very effective on both mouse strains, but can completely eradicate the salmonellae from livers and spleens when given early in the infection of CBA resistant mice.     

Association of a 70-kDa tyrosine phosphoprotein with the CD16:ζ:γ complex expressed in human natural killer cells

The CD16: ζ: γ receptor complex allows natural killer (NK) cells to recognize and eliminate antibody-coated target cells. Whereas the ectodomain of CD16 is the receptor for Fcγ domains of immunoglobulins, disulfide-linked homo- and heterodimers composed of ζ and γ are required for the cell surface expression, and signal transduction properties of the complex. Engagement of CD16 activates the tyrosine kinase pathway, which induces the tyrosine phosphorylation of several substrates, including the ζ subunit and the phospholipase C γ-1 and γ-2 isoforms. Here we show that CD 16 stimulation of either peripheral blood NK cells, leukemic NK cells, or Jurkat transformants expressing a CD16:ζ:γ receptor complex, results in the tyrosine phosphorylation of a 70 kDa ζ-associated protein (pp70). Similarly, a 70-kDa ζ-associated phosphoprotein in T cells has been shown to be a tyrosine kinase (ZAP-70). Peptide mapping analysis indicates that the 70-kDa ζ-associated phosphoproteins from T cells and NK cells are structurally indistinguishable. We conclude that the CD16:ζ:γ complex may use a ZAP-70-related non-receptor tyrosine kinase, in the CD16 signaling cascade leading to NK cell activation.     

Humeral skeletal development and plasma constituent changes in fetuses of ewes maintained on a low calcium diet from 60 days of gestation

Summary The objective of this study was to evaluate the effects of a long-term, low-calcium diet on fetal calcium metabolism and fetal skeleton skeleton development in ewes. Eleven pregnant sheep were assigned to two groups, fed either a diet low in calcium (0.26% total dry matter) or normal in calcium (0.8% total dry matter) for 2 months, starting at 60 days gestational age. The ewes fed the low calcium diet showed lower plasma levels of calcium and higher plasma levels of hydroxyproline, parathyroid hormone, and 1,25 (OH)₂D compared with the ewes fed the normal calcium diet. There were no differences in these variables between the two groups of fetuses. These observations suggest that the plasma components of calcium homeostasis measured in the fetal lamb in the present study are independent of the ewe and are not significantly affected by the presence of lowere maternal calcium for many weeks during pregnancy. Despite the ability of the fetus of the ewe on the low calcium diet to maintain relatively normal circulating plasma components of calcium homeostasis, long-term maternal hypocalcemia delayed fetal skeletal ossification as shown by histological examination of the fetal humerus. The fetal humerus from low calcium-fed ewes showed a lower proportion of bone versus cartilage (45.6±5.9 versus 57.4±4.6%, mean ±SD) lower ash content (15.4±1.5 versus 17.4±1.0%), and lower specific gravity (1.19±0.2 versus 1.22±0.02) (P<0.05) than the humerus from fetuses of normal calcium-fed ewes. This study shows that the long-term calcium intake of the ewe does affect fetal skeletal development, despite a lack of observable effects on fetal plasma concentrations of calcium or known calcium regulating hormones such as 1,25(OH)₂D or parathyroid hormone.     

Clonidine pretreatment modifies the growth hormone secretory pattern induced by shortterm continuous GRF infusion in normal man

OBJECTIVE: The aim of this study was to investigate the effect of a single dose of clonidine on the pattern of GH release in response to a 10-hour continuous GRF infusion in normal man. DESIGN: Plasma GH was analysed in samples withdrawn at 20-minute intervals, from 0900 to 1900 h, according to the following protocols: in a control study, a placebo was given at 1000 h; in other experiments, clonidine (300 micrograms, orally) was given at 1000 h, alone or together with a continuous intravenous infusion of GRF 1-29 (0.3 micrograms/kg/h) starting at this time. In another experiment, the continuous infusion of GRF 1-29 was preceded by placebo administration at 1000 h. PATIENTS: Eight normal volunteers (four women and four men), aged 19-24 years were studied. MEASUREMENTS: Plasma GH levels were measured by RIA. Analysis of the pattern of GH secretion was performed using cluster analysis. RESULTS: Clonidine induced a slight but significant increase in plasma GH values, peaking 60 to 120 minutes later; however, no significant changes were observed in indices of total and pulsatile GH release for the whole sampling period in this study. Continuous GRF administration led to increased episodic GH secretion, by augmenting GH peak amplitude, although peak frequency was not modified. An increase in interpulse GH values was also observed during GRF infusion. Pretreatment with clonidine clearly changed the pattern of GH release during GRF infusion: the amount of GH secreted was significantly higher, the number of GH peaks significantly increased, and almost all the GH was secreted within them. CONCLUSIONS: These data concord with our previous demonstration that clonidine disrupts the hypothalamic-somatotroph rhythm by inhibiting the hypothalamic release of somatostatin. Given that clonidine pretreatment induced a more physiological episodic pattern of GRF-induced GH release, the possibility of combining clonidine and GRF therapy for short stature in children is envisaged.     

Choledochoenterostomy with an anti-reflux mechanism

A new technique of choledochoenterostomy was devised to solve some of the problems of enterobiliary anastomosis with a normal calibre. The distal extremity of the common bile duct is completely surrounded by the bowel mucosa to a length of 3 cm after seromyectomy of a bowel wall rectangle of 4 × 1 cm. Experimental studies in rats and dogs demonstrated that this procedure prevents the risks of anastomotic disruption and functions like a mechanical unidirectional valve, which has great efficacy in stopping enterobiliary reflux. Studies in ten patients with obstructive jaundice with an extrahepatic biliary dilation less than 1.2 cm diameter submitted to this procedure Confirmed the experimental results. All patients were asymptomatic, without jaundice and with normalization of the liver enzymes after 2 months. The permeability of the valvular anastomosis studied by cholangiography, the HIDA ^99mTc test and manometry was quite similar to other classical biliary-enteric anastomosis. In contrast, anti-reflux efficacy was only demonstrated in patients with a valvular anastomosis.     

Initial evaluation of123|-5-|-R91150, a selective 5-HT2A ligand for single-photon emission tomography, in healthy human subjects

The mapping of 5-HT₂ receptors in the brain using functional imaging techniques has been limited by a relative lack of selective radioligands. Iodine-123 labelled 4-amino-N-[1-[3-(4-fluorophenoxy)propyl]-4-methyl-4-piperidinyl]-5-iodo-2-methoxybenzamide (¹²³I-5-I-R91150 or¹²³I-R93274) is a new ligand for single-photon emission tomography (SPET), with high affinity and selectivity for 5-HT_2A receptors. This study reports on preliminary¹²³I-5-I-R91150 SPET, wholebody and blood distribution findings in five healthy human volunteers. Maximal brain uptake was approximately 2% of total body counts at 180 min post injection (p.i.). Dynamic SPET sequences were acquired with the brain-dedicated, single-slice multi-detector system SEM-810 over 200 min p.i. Early peak uptake (at 5 min p.i.) was seen in the cerebellum, a region free from 5HT_2A receptors. In contrast, radioligand binding in the frontal cortex increased steadily over time, up to a peak at approximately 100–120 min p.i. Frontal cortex-cerebellum activity ratios reached values of 1.4, and remained stable from approximately 100 min p.i. onwards. Multi-slice SPET sequences showed a pattern of regional variation of binding compatible with the autoradiographic data on the distribution of 5-HT_2A receptors in (cerebral cortex>striatum>cerebellum). These findings suggest that¹²³I-5-I-R91150 may be used for the imaging of 5-HT_2A receptors in the living human brain with SPET.