Self-assembled growth of nanocomposites consisting of TiO(2) nanopillars and Pb(Zr(0.52)Ti(0.48))O(3) thin films.

We report for the first time the self-assembled growth of nanocomposites of 'TiO(2) nanopillars on Pb(Zr(0.52)Ti(0.48))O(3) (PZT) thin films' using a modified sol-gel processing. Both TiO(2) nanopillars and PZT thin films are simultaneously formed during the post-annealing process. The growth behaviours of TiO(2) nanopillars are controlled by adjusting the Ti excess amounts of PZT solutions and the post-annealing conditions. The self-assembled growth can be explained on the basis of the combined effects of five factors which can have influence during the annealing process: a Ti ion diffusion to the film surface, a phase separation of PZT and TiO(2), a void formation on the film surface, a Ti oxidation at the film surface under oxygen atmosphere, and a nanopillar growth on the film surface.

A boundary integral equation method using auxiliary interior surface approach for acoustic radiation and scattering in two dimensions.

This paper presents an effective solution method for predicting acoustic radiation and scattering fields in two dimensions. The difficulty of the fictitious characteristic frequency is overcome by incorporating an auxiliary interior surface that satisfies certain boundary condition into the body surface. This process gives rise to a set of uniquely solvable boundary integral equations. Distributing monopoles with unknown strengths over the body and interior surfaces yields the simple source formulation. The modified boundary integral equations are further transformed to ordinary ones that contain nonsingular kernels only. This implementation allows direct application of standard quadrature formulas over the entire integration domain; that is, the collocation points are exactly the positions at which the integration points are located. Selecting the interior surface is an easy task. Moreover, only a few corresponding interior nodal points are sufficient for the computation. Numerical calculations consist of the acoustic radiation and scattering by acoustically hard elliptic and rectangular cylinders. Comparisons with analytical solutions are made. Numerical results demonstrate the efficiency and accuracy of the current solution method.

Induction of cytochrome P450 1A1 gene expression by a vitamin K3 analog in mouse hepatoma Hepa-1c1c7 cells.

Nine vitamin K3 analogs were compared with respect to the induction of the cytochrome P450 1A1 (CYP1A1) expression in mouse hepatoma Hepa-1c1c7 cells. 6-(4-Diethylamino)phenyl-7-chloro-5,8-quinolinedione (EA4) caused a significant induction of the CYP1A1-mediated ethoxyresorufin O-deethylase activity in a time- and concentration-dependent manner. The induction was accompanied by an increase of the Cyp1a1 mRNA transcription. The transient expression of the mouse Cyp1a1-CAT gene into cells showed that EA4 induced CAT activity. However, the aryl hydrocarbon receptor and its nuclear partner, aryl hydrocarbon receptor nuclear translocator mRNA transcription, were unaffected by the EA4 treatment. When the cells were incubated with EA4 in the presence of 1 nM TCDD, the ethoxyresorufin O-deethylase activity that was induced by TCDD was significantly suppressed by EA4. Inhibition of protein synthesis by cycloheximide strongly enhanced the EA4-dependent Cyp1a1 mRNA expression. Up-regulation of protein kinase C by a 2 h preincubation with phorbol 12-myristate 13-acetate increased the EA4-dependent expression of the Cyp1a1 gene. In human cells, such as HepG2 (human hepatocarcinoma), MCF-7 (human breast adenocarcinoma cell line), and HL-60 (human promyelocytic cell line), the expression of CYP1A1 mRNA was also induced by EA4 treatment. Moreover, CYP1B1 mRNA was increased by EA4 in MCF-7 cells. These results indicate that EA4 modulates CYP1A1 and CYP1B1 expressions by transcriptional activation. Also, protein kinase C may be involved in the induction mechanism of CYP1A1 by EA4.

Quantitative assessments of physiological and biological parameters in psoriatic lesions and its correlations to the clinical severity of psoriasis.

Twenty-nine psoriatics were examined using a model with clinical, physiological and pathological assessment parameters. The three parts in this assessment model include: (1) clinical assessment: psoriasis area and severity index (PASI); (2) assessment of skin physiology and microcirculation: water content of stratum corneum, water-holding capacity of stratum corneum, transepidermal water loss, intravital dynamic videocapillaroscopy-measuring the capillary diameters and blood cell velocity in proximal nailfold of ring finger, and fluorescence angiography-measuring transcapillary Na-fluorescein(NAF) diffusion; and (3) immunohistochemistry examination: markers of proliferation (Ki67Ag), differentiation (involucrin), and inflammation (neutrophil elastase, intercellular adhesion molecule-1(ICAM-1), endothelial leukocyte adhesion molecule-1(ELAM-1)). Our results showed both the transcapillary diffusion of NAF and the expression of cell markers-dermal neutrophil elastase, epidermal ELAM-1 and Ki67Ag--correlated significantly to PASI scores (P < 0.05, linear regression). According to our results, the increased capillary permeability and inflammation markers, and enhanced expression of Ki67Ag correlated very well with PASI score. These markers could serve as alternative methods for assessment of the clinical severity of psoriatic patients.

Low affinity Ca2+-binding sites of calcineurin B mediate conformational changes in calcineurin A.

Limited proteolysis of calcineurin in the presence of Ca(2+) suggested that its calmodulin-binding domain, readily degraded by proteases, was unfolded while calcineurin B was compactly folded [Hubbard, M. J., and Klee, C. B. (1989) Biochemistry 28, 1868-1874]. Moreover, in the crystal structure of calcineurin, with the four Ca(2+) sites of calcineurin B occupied, the calmodulin-binding domain is not visible in the electron density map [Kissinger, C. R., et al. (1995) Nature 378, 641-644]. Limited proteolysis of calcineurin in the presence of EGTA, shows that, when the low affinity sites of calcineurin B are not occupied, the calmodulin-binding domain is completely protected against proteolytic attack. Slow cleavages are, however, detected in the linker region between the calmodulin-binding and the autoinhibitory domains of calcineurin A. Upon prolonged exposure to the protease, selective cleavages in carboxyl-terminal end of the first helix and the central helix linker of calcineurin B and the calcineurin B-binding helix of calcineurin A are also detected. Thus, Ca(2+) binding to the low-affinity sites of calcineurin B affects the conformation of calcineurin B and induces a conformational change of the regulatory domain of calcineurin A, resulting in the exposure of the calmodulin-binding domain. This conformational change is needed for the partial activation of the enzyme in the absence of calmodulin and its full activation by calmodulin. A synthetic peptide corresponding to the calmodulin-binding domain is shown to interact with a peptide corresponding to the calcineurin B-binding domain, and this interaction is prevented by calcineurin B in the presence but not the absence of Ca(2+). These observations provide a mechanism to explain the dependence on Ca(2+) binding to calcineurin B for calmodulin activation and for the 10-20-fold increase in affinity of calcineurin for Ca(2+) upon removal of the regulatory domain by limited proteolysis [Stemmer, P. M., and Klee, C. B. (1994) Biochemistry 33, 6859-6866].

[The pathogenic mechanism and prevention and treatment of muscle contracture after replantation of severed palm or wrist].

OBJECTIVE: To explore the pathogenic mechanism of intrinsic muscle contracture after replantation of severed palm or wrist, and put forward the prevention and treatment methods. METHODS: From 1985 to 1997, 48 cases were received replantation of severed palm or wrist, among them, 9 cases with thumb adductor contracture and 6 cases with intrinsic muscle contracture were occurred in different degree. Two cases with mild thumb adductor contracture were received conservative treatment, and 7 cases with moderate thumb adductor contracture and 6 cases with intrinsic muscle contracture were received operative treatment. The pathogenic mechanism, clinical results, and prevention methods were studied in those 15 cases. RESULTS: The postoperative function recovery was better in 4 cases, moderate in 5 cases with thumb adductor contracture, and better in 3 cases, moderate in 1 case with intrinsic muscle contracture, and moderate in 1 case, poor in 1 case with intrinsic muscle contracture of cord-like induration. Followed up 1 to 10 years, no recurrence was observed in all of 15 cases. The incidence and degree of thumb adductor contracture and intrinsic muscle contracture were closely related to the ischemia time of replanting graft. CONCLUSION: Prevention of thumb adductor contracture and intrinsic muscle contracture is most important in severed palm or wrist replantation. When the ischemia time of replanting graft is longer than 12 hours, the effective decompression in myofascial compartment is performed in time to reach satisfactory result.

Mutational spectrum of p53 gene in arsenic-related skin cancers from the blackfoot disease endemic area of Taiwan.

To understand the role of p53 tumour suppressor gene in the carcinogenesis of arsenic-related skin cancers from the blackfoot disease endemic area of Taiwan, we collected tumour samples from 23 patients with Bowen's disease, seven patients with basal cell carcinomas (BCC) and nine patients with squamous cell carcinomas (SCC). The result showed that p53 gene mutations were found in 39% of cases with Bowen's disease (9/23), 28.6% of cases with BCC (2/7) and 55.6% of cases with SCC (5/9). Most of the mutation sites were located on exon 5 and exon 8. Moreover, the results from direct sequencing indicated that missense mutations were found at codon 149 (C-->T) in one case, codon 175 (G-->A) in three cases, codon 273 (G-->C) in three cases, codon 292 (T-->A) in one case, codon 283 (G-->T) in one case, codon 172 (T-->C) in one case and codon 284 (C-->A) in one case. In addition, silent mutations were also found in four cases. These mutations were located at codons 174, 253, 289 and 298 respectively. In immunohistochemistry analysis, p53 overexpression was found in 43.5% (10/23) of cases with Bowen's disease, 14% (1/7) of cases with BCC and 44% (4/9) of cases with SSC. These findings showed that p53 gene mutation rate in arsenic-related skin cancers from the blackfoot disease endemic area of Taiwan is high and that the mutation types are different from those in UV-induced skin cancers.

Study of Dynamic Microcirculatory Problems in 'Blackfoot Disease' - Emphasizing Its Differences from Arteriosclerosis.

The cutaneous microcirculation can be divided into thermoregulatory shunt vessels and nutritive skin capillaries. Flux in nonnutritional shunt vessels dominates the signal recorded by the laser Doppler flowmeter. Computerized videophotometric capillaroscopy is a sensitive method for assessing cutaneous nutritive microcirculation. Using patients with blackfoot disease and arteriosclerosis as disease models, we evaluated the sensitivity and clinical usefulness of these relatively new techniques for peripheral vascular disorders. In blackfoot disease, blood flux measured by the laser Doppler flowmeter in the affected toe was lower than that in the nonaffected toe. In symptom-free fingers, blood flow was not significantly different between blackfoot disease and arteriosclerosis. However, blood flow in both diseases was lower than that of the control group. Patients who had the same status of thermoregulatory flow and eyeground arteriosclerotic classification underwent a 1-min arterial occlusion of the digits. The postocclusive reactive hyperemia response (PRH) of nailfold capillary loops was evaluated. All parameters for PRH for the cutaneous nutrient microcirculation including resting capillary blood cell velocity (rCBV), peak capillary blood cell velocity (pCBV) and time to pCBV were more significantly disturbed in the blackfoot disease group than in the arteriosclerotic group. On the basis of the results of this study, dynamic capillaroscopy provides a new approach for the early detection of circulatory disturbances resulting from different mechanisms. Copyright 1995 S. Karger AG, Basel

Responses of cutaneous microcirculation to cold exposure and neuropathy in vibration-induced white finger.

In order to clarify the mechanisms of cold temperature on vibration-induced white finger (VWF), three groups of forestry chain saw operators served as the subjects of this study. Groups I and II worked in a cold high-altitude area, and group III worked in a warm low mountain climate. Group I workers had VWF sign [VWF(+)] but groups II and III did not [VWF(-)]. In the present study, finger nailfold microcirculation before and after cold exposure, finger skin sympathetic alpha receptor response, and sympathetic skin response were measured. The results showed that there was no significantly different neuropathy in any of the groups. However, vibration-induced microcirculatory disturbances including blood stasis and red blood cell aggregation were more prominent in VWF(+) group, whereas both of the VWF(-) groups (groups II and III) had no significant difference in microcirculatory disturbances. This suggests that the severity of the microcirculatory disturbances is dose-effect correlated and is aggravated by cold in vibration syndrome. Thus it can be realized that a cold working environment is an important contributing factor in causing microcirculatory disturbances of VWF.

[Clinical and scanning electron microscopic studies on Norwegian scabies infection].

Two typical cases of Norwegian scabies were studied clinically, scanning electron microscopically and histopathologically. Case 1 was a boy with Down's syndrome and case 2 was a man with adult T cell leukemia/lymphoma. Their clinical pictures showed hyperkeratotic plaques and warty crusts on hands, feet, ears, elbows and buttocks. Direct examination of the KOH preparation revealed many embryonated sarcoptic eggs, postpartum egg-shells, fecal pellets, larvae and male and female adult mites. Histopathologic examination showed several burrows inside the thick horny layer. Many sarcoptic egg-shells, mites and fecal pellets were found in the burrows. Psoriasiform hyperplasia and parakeratosis were noted, too. The size and shape of the sarcoptic eggs and the detailed structure of mites and molt were observed by using a scanning electron microscope. Besides, hook-like structures were noted at the tarsi of both forelegs and hindlegs. We suggest that the larvae crawl out from longitudinal openings in the egg-shell by the use of hook-like structures. The mites also used these hook-like structures to make the burrows. Scanning electron microscopy provides a good method to understand the dynamics of these burrowing parasites. It is helpful in illustrating the behavior of the scabies mites in their burrows in Norwegian scabies patients.

Effects of temperature on cutaneous microcirculation in vibration syndrome.

In order to clarify the role of cold on the cutaneous microcirculation in vibration syndrome, groups of rabbits vibrated at 4 degrees and room temperature served as the subjects of this study. A cold provocation test, capillary microscopy, and laser-Doppler flowmetry were used to evaluate the microcirculations of the test rabbits. The results indicated that vibration-induced impairment of the microcirculation was more prominent in the 4 degrees vibration group than in the room temperature group. The severities of the microcirculatory disturbances were dose-effect correlated. Vibration induced not only functional disturbances but also structural destruction of the capillaries. Furthermore cold temperatures enhanced these abnormalities of the blood vessels.

Isolation of Cryptococcus albidus var. albidus in patient with pemphigus foliaceus.

Cryptococcus albidus var. albidus was isolated from the blood of a patient with pemphigus foliaceus after steroid therapy. This organism was found in triple extract peptone medium which is used in our laboratory for blood culture to detect aerobic and anaerobic bacteria. Identification of Cryptococcus was made by the API 20C yeast carbohydrate assimilation test, together with conventional procedures. These include the demonstration of chlamydospore production, germ tube test, urease test, nitrate assimilation test and colony morphology. The patient infected with Cryptococcus albidus var albidus had a good response to oral ketoconazole therapy, then the recovered and was discharged. The isolate obtained from this case may be regarded as an etiologic agent in fungemia.

[Skin eruption and histopathological changes in dengue fever].

Evaluation of histopathological and ultrastructural changes in skin eruptions of three dengue fever patients was performed. The main pathological findings in skin lesions were swelling of the endothelial cells in small vessels of papillary dermis, diapedesis of neutrophils, extravasation of erythrocytes and perivascular mononuclear cells infiltration. Ultrastructural observation revealed degeneration of endothelial cells and neutrophils. The relationships among endothelial cell damage, cell infiltration and hemorrhage were discussed.