Tape-stripping method in man: comparison of evaporimetric methods

BACKGROUND/PURPOSE: If the occlusion time of a closed chamber evaporimeter on the skin is too long, saturation might occur. We previously compared an open chamber and a closed chamber device on healthy volunteers. Comparable data on stripped skin with higher evaporation rates are not available. This study compares the sensitivity and correlation of open and closed chamber devices in a tape-stripping human model. The amount of tape removed SC was also quantified with a protein assay method. METHODS: Ten healthy volunteers (six male and four female; seven Caucasians and three Asian; mean age 38+/-16) were enrolled. In a randomized manner, one forearm was measured by an open chamber device and the opposite by a closed chamber device. After recording baseline measurements, 20 strippings were taken on each test site with tape disks. Transepidermal water loss (TEWL) was measured at the end of 10 and 20 tape strippings at each test site. Stratum corneum (SC) aggregates in the strips was assayed. RESULTS: The mean values obtained from two devices were similar after 10 trips and 20 strips. There was no statistically significant difference. The closed chamber device showed a slightly higher (but not significant) inter-individual coefficient of variation. SC aggregates in the strips were similar and without a statistically significant difference. CONCLUSION: The study suggests that both devices might yield similar TEWL values on stripped human skin in vivo.     

Reorganization of cytoplasm in the zebrafish oocyte and egg during early steps of ooplasmic segregation.

The aim of this work is to determine when and how ooplasmic segregation is initiated in the zebrafish egg. To this end, the organization of the ooplasm and vitelloplasm were examined in oocytes and eggs shortly after activation. Ooplasmic segregation, initiated in the stage V oocyte, led to the formation of ooplasmic domains rich in organelles, and ribonucleoproteins. A linear array of closely arranged peripheral yolk globules separated an outer domain of ectoplasm from an inner domain of interconnected endoplasmic lacunae. The structure of this yolk array and the distribution of microinjected labeled tracers suggests that it may provide a barrier limiting ooplasm transit. Loosely arranged yolk globules at the animal hemisphere allow wide connections between the endoplasm and a preblastodisc domain. Activation caused further segregation of ooplasm, reorganization of endoplasmic lacunae, and blastodisc growth. The presence of an endoplasmic cytoskeleton suggests that these changes may be driven by microtubules and microfilaments.     

Localization of NADPH-diaphorase containing neurons in the spinal dorsal horn and spinal sensory ganglia of the turtle Chrysemys d’orbigny

 NADPH-diaphorase positive (NDP) neurons and nerve fibers were found in the spinal dorsal horn (DH) and sensory ganglia of the turtle Chrysemys d’orbigny. Three well-defined types of NDP neurons were found in the DH: (a) elongated nerve cells with two radially arranged dendritic branches, (b) neurons with rostro-caudal dendritic branches, (c) bitufted neurons with two, practically symmetric branches that project to the ipsilateral and contralateral dorsal horns. A combination of the techniques that reveal NADPH-diaphorase activity with the horseradish peroxidase transganglionic labeling of the dorsal root collaterals, suggested that NDP neurons of the DH are second-order cells of the spinal sensory pathway. NDP neurons were also found in the spinal sensory ganglia at all metameric levels. Our findings indicate that the DH of turtles, like that of mammals, contains both the enzymatic machinery and the neural connections required to postulate the participation of nitric oxide in ”plastic phenomena” such as hyperalgesia and central sensitization. Two other alternatives or complementary hypotheses are discussed: (a) NDP neurons in the DH and sensory ganglia may represent specific cell populations involved in the processing of sensory visceral information; (b) NADPH-diaphorase reactivity may indicate sustained levels of neuronal activity. Received: 12 February 1996 / Accepted: 2 August 1996     

Estrogen receptors in the external anal sphincter

Inasmuch as anal competence in women is reduced after the age of 50 years, it may be dependent on effects of estrogens. In this study, samples of the external anal sphincter were analyzed for the presence of estrogen receptors and were found to be present at a median concentration of 5.0 fmol per milligram of protein (range, 1.9 to 13) in women (n = 7), and 1.1 fmol per milligram of protein (range, 0 to 3.2) in men (n = 7). These findings are of interest with regard to the treatment of idiopathic anal incontinence.     

Techniques for high-resolution MR imaging of atherosclerotic plaque

Atherosclerotic cardiovascular disease is the most common cause of death in the United States. Investigation of atherosclerotic plaque morphology and composition is important because the findings may be useful in predicting prognosis or response to therapy. This study presents high-resolution magnetic resonance (MR) imaging techniques developed on a 1.5-T whole-body imager with a custom-built surface coil, for characterizing the composition and morphology of plaque removed at carotid endarterectomy. The initial comparison of MR imaging and histologic results showed good correlation. In conjunction with MR angiography, these techniques could be used in in vivo imaging to define the size, location, and contents of atherosclerotic plaque at the carotid bifurcation.     

Evaluating the self-esteem of myopic children over a three-year period: The COMET Experience.

PURPOSE: The purposes of this study were to evaluate self-esteem over 3 years in the 469 myopic children participating in the Correction of Myopia Evaluation Trial (COMET), and to examine its relationship with lens assignment (progressive addition lenses [PALs] vs. single-vision lenses [SVLs]), myopia progression, and several other ocular and demographic characteristics. METHODS: Data collection included refractive error measurements, child-reported visual symptoms, attitude toward glasses, adherence, and self-esteem as measured by the Self-Perception Profile for Children (SPPC). A two-way analysis of variance (treatment group x time) was performed to examine whether PAL and SVL wearers differed in self-esteem over time. Multiple regression analyses were used to evaluate associations between self-esteem at follow-up and relevant factors identified by univariate analyses. RESULTS: Regardless of lens assignment or myopia progression, COMET children reported moderate to high levels of self-esteem at follow-up in the areas of scholastic and athletic competence, physical appearance, social acceptance, behavioral conduct, and global self-worth. Mean scores ranged from 2.87 (+/- 0.68) on athletic competence to 3.40 (+/- 0.56) on global self-worth. Self-esteem changed significantly (p < 0.05) over 3 years in the domains of scholastic competence, social acceptance, and physical appearance. Self-esteem at follow-up was associated with visual symptoms, attitude toward glasses, age, gender, and ethnicity. CONCLUSIONS: Lens assignment and myopia progression were not associated with self-esteem in the COMET cohort. These children had high levels of self-esteem, suggesting that having myopia does not negatively impact self-esteem. Follow-up reports will monitor self-esteem and related factors in this cohort of myopic children over the course of adolescence and early adulthood.     

Neurotrophin-like immunoreactivity in the human pre-term newborn, infant, and adult cerebellum

The immunohistochemical occurrence of the neurotrophin (NT) proteins nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), neurotrophin-4 (NT-4), and neurotrophin-3 (NT-3) is shown in the pre-term newborn, infant, and adult human post-mortem cerebellum. The NT-like immunoreactive structures were unevenly distributed and showed regional differences among cerebellar lobules and folia. NGF-, NT-4-, and NT-3-positive neuronal perikarya were observed in all specimens examined. At variance with the other neurotrophins, the BDNF antiserum labelled neuronal cell bodies only in newborn life and infancy, as well as extensive nerve fibre systems, whose density increased with age. The NT-antibodies, tested by Western blot on human cerebellum homogenates, revealed immunoreactive bands corresponding to proteins of heterogenous molecular weight. The results obtained provide a first demonstration of the tissue localization of the NTs in the human cerebellum from perinatal to adult age, thus suggesting their involvement in the development, differentiation and maintenance of the cerebellar connectivity. Codistribution of the four NTs or sets of them was observed in cortical and deep nuclei neurons. Multiple trophic roles for NTs, encompassing the classic target-derived and local mechanisms of support, are envisaged as significant in development, differentiation, and maintenance of the human cerebellar connectivity.     

Relative weight of glucose, insulin and parathyroid hormone in the urinary loss of phosphate by chronically diabetic rats

This report deals with the relationships between glucose (G) and insulin on the tubular transport of phosphate (P) in chronically diabetic rats with high plasma levels of parathyroid hormone (PTH). Alloxan-induced diabetes leads to phosphorus depletion of the soft tissues. This phenomenon appears associated with weight loss and negative P balances caused by the increased urinary P excretion. Administration of 2 IU of insulin/100 g body weight (bw) to diabetic rats normalized their P balance and body weight. The effect of parathyroid function on the P metabolism of diabetic rats was investigated with balance experiments. Diabetic rats, intact or thyroparathyroidectomized (TPTX), have a greater urinary excretion of P than their controls. However, in control rats, the ratio intact:TPTX for urinary P is 1.0:0.76, showing the antiphosphaturic effect of parathyroid ablation. For diabetic animals, on the other hand, the ratio is 1.0:1.44. The simultaneous deficit of insulin and PTH thus quadruples the urinary P loss, instead of compensating for each other. The contribution of insulin deficit and hyperglycemia to the defect in tubular reabsorption (TRP) was investigated with clearance experiments (done on anesthetized, perfused rats). Five experimental groups were used: Controls (C), diabetics (D), controls+glucose (C+G), diabetics+insulin (D+I) and diabetics+insulin+glucose (D+I+G). All experimental groups showed a linear relationship between the TRP of P and G. The regression equation for C is significantly different (F=40.1, P<0.001) from that of D animals. The slope value measure the number of μmoles of P per μmol of G reabsorbed. For C and D rats, the ratio P:G approximates 1:4 and 1:20, respectively. The increase in P:G ratios represents the competition between both substrates for tubular resorption. Glycemias up to 11 mM (C and D+I) exist concurrent with the P:G ratio 1:4. Glycemias above 25 mM (D, C+G and D+I+G) produce a P:G ratio of 1:20. Fractional excretion of P (FEP) increased significantly in untreated, chronically diabetic rats (0.47± 0.12 vs controls=0.05±0.01, P<0.001). After a single intramuscular injection of insulin, the FEP decreased as a function of insulin levels. To normalize the FEP of diabetic rats in short-term experiments, insulin had to be administered in doses that produce plasma insulin levels 25 times greater than normal. The general information afforded by the present experiments shows that in untreated, chronically diabetic rats, insulin deficit plays an indirect role. The absence of PTH enhances the effect of hyperglycemia. The latter and the concurrent tubular overload of glucose are the cause of hyperphosphaturia in these animals. Received: 10 September 1996 / Accepted in revised form: 18 April 1997