Effects of Cigarette Smoking on Bilateral Skin Conductance

Bilateral skin conductance was recorded from 8 male and 8 female cigarette smokers and from 8 male and 8 female nonsmoker control subjects on two different days. On one day smokers smoked a cigarette prior to the recording session and on the other they remained abstinent. Subjects also engaged in tasks designed to differentially involve the cerebral hemispheres. SCR asymmetry was measured using two different indices. During both the resting and task periods smokers had larger SCRs in their right than left hands following smoking. Unlike control subjects during the first recording session, smokers did not show task related changes in SCR asymmetry. During tasks smokers showed smaller SCRs in both hands following smoking than following abstinence. Changes in SCR asymmetry associated with smoking were seen in subjects who smoked more cigarettes, reported more subjective craving, were more introverted, and indicated a preference for cognitive processes and strategies associated with the left hemisphere. Results are discussed in terms of relative involvement of the cerebral hemispheres following smoking and smoking abstinence.     

Timing of deletion of autoreactive V{beta}6+ cells and down-modulation of either CD4 or CD8 on phenotypically distinct CD4+8+ subsets of thymocytes expressing intermediate or high levels of T cell receptor

In this paper we describe a differentiation sequence amongst adult murine thymocytes which goes from CD4+8+3lo(low) to CD4+8+3int(intermediate) to CD4+8+3hi(high) and then to mature single positive CD3hi thymocytes. Phenotypic characterization of CD4+8+3int/hi cells for a number of other surface markers is consistent with them being in transition from CD4+8+3lo phenotype to mature phenotype. The same observation was made for sensitivity towards ionomycin-mediated apoptosis. In the thymus of Mls-1a mice, where autoreactive TCR-V beta 6+ cells are negatively selected, deletion of TCR-V beta 6+ cells was first detected in the CD4+8+3int subset, and was complete by the CD4+8+3hi stage, suggesting that up-regulation of the TCR/CD3 complex is required for deletion of Mls-1a autoreactive thymocytes. No sign of apoptosis was detected among any fresh thymocyte subsets suggesting that apoptotic cells are rapidly cleared from the thymus. The CD4+8+3int/CD4+8+3hi cells are therefore populations in transit from the typical cortical thymocytes to the mature T-cells.     

Giant mitochondria distinct from enlarged mitochondria in secretory and ciliated cells of gerbil trachea and bronchioles

Numerous mitochondria ranging from slightly larger than normal to several micrometers in diameter (giant) were found in about one-half the serous secretory cells in the surface epithelium of the normal gerbil trachea and proximal bronchi. Tracheal serous cells of mice also were found to contain numerous giant mitochondria. Clara cells of gerbil bronchioles contained abundant giant mitochondria in addition to normal tubular mitochondria and the second population of enlarged spherical mitochondria that have been described in Clara cells of several genera. In contrast, mouse Clara cells revealed the normal tubular and the enlarged spherical mitochondria but no giant mitochondria. A survey of a number of cell types in gerbils failed to disclose hypertrophied mitochondria outside tracheobronchial surface epithelium and bronchioles. The mitochondrial enlargement resulted from an increase of matrix but not cristae. The expansion of matrix displaced the relatively sparse cristae into small collections compressed against the outer membrane. The prevalence of giant mitochondria and of granular endoplasmic reticulum is similar among cells, and these two organelles are codistributed within cells. The megamitochondria and granular reticulum occupy a central stratum, whereas normal mitochondria occur in the apical and basal regions. The giant mitochondria are considered related to a normal biologic activity that is characteristic of respiratory tract epithelium of mice and gerbils selectively and is more prominent in secretory cells than in ciliated cells.     

Theoretic and experimental analysis of the ability of a commercially prepared system to detect mixtures of bacteria.

The validity of the biochemical identification of bacteria presumes that the inoculum consists of a pure growth of bacteria. The detection of mixtures of bacteria with the Analytab Enteric (API 20E) system was tested. Using a computer to predict the response of the API 20E system to mixed cultures, the presence of a mixture was not detected in 15% of all pairwise combinations of 324 common organisms of the Enterobacteriaceae family and in 19% of all pairwise combinations of Enterobacteriaceae with four gram-positive cocci. These theoretic predictions were confirmed experimentally for selected mixtures in which the bacteria were combined in equal concentrations. These results indicate that a purity subculture plate must be used to insure the detection of mixtures of bacteria, because the API 20E system fails to detect a large number of mixtures and may erroneously identify the organisms in such mixtures.     

Single-stage methods of hypospadias repair

Summary The repair of all hypospadias in one stage represents state of the art in virtually all instances. Implicit in the repair of hypospadias is the correction of chordee, the construction of the neourethra such that the meatus is located on the tip of the glans, and the creation of a penis which is cosmetically appropriate. Described in this paper are most of the currently employed methods utilized for the repair of hypospadias in a single stage. The techniques described herein, in skilled hands, yield good results in 85–90% of cases. Repairs of hypospadias which have been designed and which are recommended for the occasional operator have no place in today's surgical therapy.     

Conformational flexibility of the methyltetrazolethiomethyl side chain of beta-lactam antibiotics. A computer graphics study

Analysis of X-ray crystallographic data for cephalosporins and 1- oxacephalosporins shows that, although the 1-methyl-1H- tetrazol -5- ylthiomethyl side chain at position 3 of a bicyclic beta-lactam nucleus has certain conformational preferences, it also has considerable flexibility. Both the C4 = C3-C3'-S and C3-C3'-S-C5" torsional angles are frequently observed in the vicinity of +/- 90 degrees. The distance between the tetrazole ring carbon C5" and the 4-carboxyl carbon ranges from 4.07 to 5.65 A. Mean bond lengths and bond angles for the 3 and 4 side chains are tabulated.     

Exclusion criteria of DSM-III. A study of co-occurrence of hierarchy-free syndromes

The diagnostic criteria of the third edition of the DSM-III often state that one diagnosis cannot be made if it is "due to" another disorder. Using data from the National Institute of Mental Health Diagnostic Interview Schedule, with a sample of 11,519 subjects from a community population, we found that if two disorders were related to each other according to the DSM-III exclusion criteria, then the presence of a dominant disorder greatly increased the odds of having the excluded disorder. We also found that disorders, which DSM-III says are related to each other, were more strongly associated than disorders, which DSM-III says are unrelated. However, we also found there was a general tendency toward co-occurrence, so that the presence of any disorder increased the odds of having almost any other disorder, even if DSM-III does not list it as a related disorder. We concluded that empirical studies are needed to study the assumptions underlying the use of a diagnostic hierarchy.     

Toward ‘seeing’ critically: a Bayesian analysis of the impacts of a critical pedagogy

Advances in Health Sciences Education - Critical reflection supports enactment of the social roles of care, like collaboration and advocacy. We require evidence that links critical teaching...     

A Three-Year Longitudinal Study Comparing Bone Mass,Density, and Geometry Measured by DXA,pQCT, and Bone Turnover Markers in Children with PKU Taking L-Amino Acid or Glycomacropeptide Protein Substitutes

In patients with phenylketonuria (PKU), treated by diet therapy only, evidence suggests that areal bone mineral density (BMDa) is within the normal clinical reference range but is below the population norm. Aims: To study longitudinal bone density, mass, and geometry over 36 months in children with PKU taking either amino acid (L-AA) or casein glycomacropeptide substitutes (CGMP-AA) as their main protein source. Methodology: A total of 48 subjects completed the study, 19 subjects in the L-AA group (median age 11.1, range 5–16 years) and 29 subjects in the CGMP-AA group (median age 8.3, range 5–16 years). The CGMP-AA was further divided into two groups, CGMP100 (median age 9.2, range 5–16 years) (n = 13), children taking CGMP-AA only and CGMP50 (median age 7.3, range 5–15 years) (n = 16), children taking a combination of CGMP-AA and L-AA. Dual X-ray absorptiometry (DXA) was measured at enrolment and 36 months, peripheral quantitative computer tomography (pQCT) at 36 months only, and serum blood and urine bone turnover markers (BTM) and blood bone biochemistry at enrolment, 6, 12, and 36 months. Results: No statistically significant differences were found between the three groups for DXA outcome parameters, i.e., BMDa (L2–L4 BMDa g/cm²), bone mineral apparent density (L2–L4 BMAD g/cm³) and total body less head BMDa (TBLH g/cm²). All blood biochemistry markers were within the reference ranges, and BTM showed active bone turnover with a trend for BTM to decrease with increasing age. Conclusions: Bone density was clinically normal, although the median z scores were below the population mean. BTM showed active bone turnover and blood biochemistry was within the reference ranges. There appeared to be no advantage to bone density, mass, or geometry from taking a macropeptide-based protein substitute as compared with L-AAs.