Onset of keratin 17 expression coincides with the definition of major epithelial lineages during skin development

The type I keratin 17 (K17) shows a peculiar localization in human epithelial appendages including hair follicles, which undergo a growth cycle throughout adult life. Additionally K17 is induced, along with K6 and K16, early after acute injury to human skin. To gain further insights into its potential function(s), we cloned the mouse K17 gene and investigated its expression during skin development. Synthesis of K17 protein first occurs in a subset of epithelial cells within the single-layered, undifferentiated ectoderm of embryonic day 10.5 mouse fetuses. In the ensuing 48 h, K17-expressing cells give rise to placodes, the precursors of ectoderm-derived appendages (hair, glands, and tooth), and to periderm. During early development, there is a spatial correspondence in the distribution of K17 and that of lymphoid-enhancer factor (lef-1), a DNA-bending protein involved in inductive epithelial-mesenchymal interactions. We demonstrate that ectopic lef-1 expression induces K17 protein in the skin of adult transgenic mice. The pattern of K17 gene expression during development has direct implications for the morphogenesis of skin epithelia, and points to the existence of a molecular relationship between development and wound repair.     

Spectroelectrochemical characterization of the metal centers in carbon monoxide dehydrogenase (CODH) and nickel-deficient CODH from Rhodospirillum rubrum

Carbon-monoxide dehydrogenase (CODH) from Rhodospirillum rubrum contains two metal centers: a Ni-X-[Fe4S4]2+/1+ cluster (C-center) that serves as the COoxidation site and a standard [Fe4S4]2+/1+ cluster (B-center) that mediates electron flow from the C-center to external electron acceptors. Four states of the C-center were previously identified in electron paramagnetic resonance (EPR) and M?ssbauer studies. In this report, EPR-redox titrations demonstrate that the fully oxidized, diamagnetic form of the C-center (Cox) undergoes a one-electron reduction to the Cred1 state (gav = 1.87) with a midpoint potential of -110 mV. The reduction of Cox to Cred1 is shown to coincide with the reduction of an [Fe4S4]2+/1+ cluster in redox-titration experiments monitored by UV-visible spectroscopy. Nickel-deficient CODH, which is devoid of nickel yet contains both [Fe4S4]2+/1+ clusters, does not exhibit EPR-active states or reduced Fe4S4 clusters at potentials more positive than -350 mV.     

A double lumen suprapubic urodynamic catheter

A 7.5 FG double lumen suprapubic urodynamic catheter has been developed to avoid the effects of urethral catheterization and provide reliable continuous pressure monitoring. The device is an adapted central venous catheter which is easily introduced through a peel-away sheath, after the insertion of a guide wire.     

Risk factors for breast cancer in women with a breast cancer family history

For the study of the relationship of the pelviureteric system of one kidney to that of the contralateral one, bilateral cutaneous ureterostomy was performed in 14 dogs. The renal pelvis (RP) and ureter (U) of one side were distended separately with a balloon filled with saline in increments of 1 and 0.25 ml, respectively, and the pressure response of the contralateral RP and U was recorded. The test was repeated after anesthetization of the RP and U. RP distension with 1 ml of saline effected a pressure rise (P < 0.05) in the ipsilateral RP but no pressure response in the ipsilateral U or the contralateral RP or U (P > 0.05). RP distension with 2, 3, and 4 ml of saline induced a significant pressure rise in the ipsi- and contralateral RP but not in the ureters. Ureteric distension produced a pressure elevation (P < 0.05) on the ipsilateral U but had no effect on the contralateral U (P > 0.05) or on either of the renal pelves (P > 0.05). Distension of the anesthetized RP or U effected no pressure response in any of the ipsi- or contralateral RPs or Us. In conclusion, distension of the RP with large volumes led to an increase in pressure in the contralateral RP but not in the U. A reflex relationship is postulated to exist between the two renal pelves and to be mediated through a reflex we call the reno-renal pelvic reflex. It seems that this reflex acts to allow either of the kidneys to share an extra load of the other one by increasing the contractile activity of the RP, thus assumedly assisting the regulation of urine flow.     

Germ cell loss in the XXY male mouse: altered X-chromosome dosage affects prenatal development

Attempts to describe the clinical heterogeneity of schizophrenia have consisted of categorical subtyping and a dimensional approach using factor analysis. The latter has yielded three dimensions or subsyndromes: positive, negative and disorganisation. The aim of this study is to explore to what degree these subsyndromes are correlated within 114 sibling pairs (185 individuals) with DSM-III-R schizophrenia or schizo-affective disorder who were assessed for the lifetime presence or absence of the positive, negative, affective and disorganisation subsyndromes. Ratings were based on the core symptoms of each subsyndrome using a modified Krawieka scale. First rank symptoms were also included in the analysis. Coincidence was assessed by application of the binomial theorem to the frequency of occurrence of subsyndromes in this set of siblings. The disorganisation subsyndrome was shared above chance expectation (chi2=9.15, P < 0.01 for all sibling pairs). The significant results for the disorganisation subsyndrome suggest that it may be a suitable phenotypic marker for genetic linkage studies.     

Suppression of evoked IPSPs by arachidonic acid and prostaglandin F2 alpha

Arachidonic acid (AA) and certain prostaglandins appear to antagonize GABAA receptors in synaptoneurosomes [18]. We report here that perfusing hippocampal slices with AA or prostaglandin F2 alpha diminishes evoked IPSP conductance and increases CA1 pyramidal cell input resistance. The effects of the two compounds were similar, though not identical, in time course, magnitude, and response to washout. These findings suggest that high levels of AA and its metabolites may bias neurons towards excitation.     

Epididymal manifestations of urogenital tuberculosis

We report the case of a 33-year-old man with a severe Crohn's disease since the age of sixteen. He presented with acne and palmoplantar pustulosis associated with a right knee synovitis. Investigations revealed a major axial bone condensation. The association synovitis-acne-pustulosis-hyperostosis-osteitis leaded to the diagnosis of SAPHO syndrome associated with Crohn's disease.