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Lichen-planus-like keratosis is usually diagnosed pathologically; rarely, a definitive diagnosis can be made grossly in the clinic. Only a few cases of lichen-planus-like keratosis have been reported in China. The purpose of this study was to investigate the clinical and pathological features of lichen-planus-like keratosis in China. Fifty cases of lichen-planus-like keratosis patients diagnosed pathologically during a 5-year period in our clinic were analyzed. Clinical features were recorded. Sectioned specimens were subjected to hematoxylin and eosin staining to observe pathological changes. Results showed that there were 34 males and 16 females (ratio 2:1) with an average age of 61.2 years. Most of the lesions were single papules or plaques with rough surfaces. They were distributed on the face, larger than 1 cm, and dark red to brown in color. Only one case (2%) was considered to be lichen-planus-like keratosis clinically. By hematoxylin and eosin staining, solar lentigo and solar elastosis could be found in 68% and 32% of lichen-planus-like keratosis lesions, respectively. Eosinophil (42%) and plasma cell (36%) infiltration was also found frequently. Exoerythrocytes could be detected in 50% of the cases. Lichen-planus-like keratosis is not uncommon in clinical practice in China, the diagnosis of lichen-planus-like keratosis should be made by a combination of clinical manifestations and pathological changes. It is better to classify lichen-planus-like keratosis as a benign skin tumor. More attention should be paid to lichen-planus-like keratosis in China. [ABSTRACT FROM AUTHOR]

Soybean cyst nematode (SCN; Heterodera glycines) is one of the most important pests affecting soybean production. The best method of control of SCN is through the development of resistant cultivars. However, limited progress has been made in soybean breeding in China because most modern cultivars have no resistance to SCN. The distribution and phenotype of 432 immune or highly resistant Chinese accessions were surveyed and a primary core collection was selected as a representative sample for further analyses. Using evenly distributed simple sequence repeat markers, five selection methods were applied to the primary core collection and the optimal method was chosen to establish a core collection, which consisted of 28 accessions. These encompassed 70.8% of the allelic variation present in the overall resistant collection. The 28 accessions differed from the reference resistant accessions at the genomic level, indicating that Chinese resistant accessions are distinct from known resistant accessions. This applied core collection provides a rational framework for undertaking diversity surveys, using genetic variation for the investigation of complex traits and for the discovery of novel traits. (Managing editor: Li-Hui) [ABSTRACT FROM AUTHOR]

The prevalence of cosmetic allergic contact dermatitis (CACD) in Chinese eczema patients (CEP) has not been reported. The purpose of our study was to analyse CACD in CEP and examine the frequency of patch test (PT) reactions to common cosmetic-related allergens (CRA). 378 consecutive CEP patch tested with a modified European standard series of allergens during a 2-year period in our clinic were analysed. 73 patients (19.3%) were considered as suspected CACD and 37 patients (9.8%) were confirmed. The frequencies of the positive PT reactions in suspected CACD and confirmed CACD to at least 1 CRA were 64.4% and 89.2%, to para-phenylenediamine (PPD) were 31.5% and 59.5%, to fragrance mix (FM) were 27.4% and 32.4% and to imidazolidinylurea were 5.5% and 8.1%, respectively. These results were much higher than those of CEP without cosmetic reactions (26.3% for at least 1 CRA, 5.8% for PPD, 8.8% for FM, and 0 for imidazolidinylurea) ( P < 0.01 for all, Chi-square test and Fisher's exact test). These results suggested that CACD is very common in CEP patch tested. PPD and FM are the leading allergens identified. CACD should be strongly considered in CEP with positive PT reactions to PPD, FM and imidazolidinylurea. [ABSTRACT FROM AUTHOR]

Tetraspanin proteins have been shown to associate with activated PKC and to link PKC to its substates. In the present study, we examined the role of CD63 in mediating the effect of protein tyrosine kinase (PTK) on ROMK channels. Immunoprecipitation with CD63 antibody of lysates derived from renal outer medulla and cortex or HEK293 cells transfected with CD63 and c-Src led to co-precipitation of c-Src. We then used two electrode voltage clamp to study the effect of CD63 on ROMK channels in Xenopus oocytes. Although coexpression of CD63 had no effect on K currents in oocytes injected with ROMK1, it significantly enhanced the c-Src-induced inhibition of ROMK channels. The effect of CD63 on the cSrc-induced inhibition is not due to a decreased expression of ROMK1 channels, because inhibition of PTK with Herbimycin A abolished the inhibitory effect of c-Src on ROMK channels in oocytes injected with ROMK1+c-Src+CD63. Furthermore, coexpression of CD63 enhanced tyrosine phosphorylation of ROMK1 in HEK293 cells. Deletion of the last ten amino acids of the C-terminus of CD63, which contains an endocytosis motif, did not affect the association between c-Sre and CD63. However, coexpression of the truncated CD63 abolished the inhibitory effect of c-Src on ROMK channels and decreased tyrosine phosphorylation of ROMK1 in comparison to that of HEK293 cells transfected with c-Src+ROMK1 or c-Src+ROMK1+CD63. Also, inhibition of PTK did not increase K currents in oocytes injected with ROMK1, c-Src and truncated CD63. We conclude that CD63 is associated with c-Src in the kidney and that coexpression of CD63 enhances the tyrosine phosphorylation of ROMK channels. [ABSTRACT FROM AUTHOR]

We investigated the effect of H202 on ROMK-like small conductance K (SK) channels in the CCD and the role of NOX2 in mediating the effect of low K intake on renal K excretion and SK channels. K-restriction increased superoxide concentrations and decreased SK channel activity. The effect of superoxide anions and related products on SK channels has also been shown by experiments in which application of 100 uM H202 inhibited SK channels in the rat CCD. The effect of H202 was completely abolished by blocking P38, ERK and protein tyrosine kinase. Deletion of gp91phox significantly attenuated the effect of low K intake on superoxide production, c-Src expression and tyrosine phosphorylation of ROMK. Patch-clamp experiments demonstrated that the effect of low K intake on SK channel activity was significantly attenuated in the CCD from gp91phox(-/-) mice and completely abolished by tempol treatment. We also used immunocytochemical staining to examine the ROMK distribution in wt, gp91phox(-/-) and wt mice with tempol treatment in response to K restriction. K-restriction decreased apical staining of ROMK in wt mice. In contrast, a sharp apical ROMK staining was observed in the tempol-treated wt or gp91phox(-/-) mice. Metabolic cage study has further shown that urinary K loss is significantly higher in gp91phox(-/-) mice than in wt mice. We conclude that superoxide anions play a key role in suppressing K secretion during K restriction and that NOX2 is involved in mediating the effect of low K intake on renal K secretion and ROMK channel activity. [ABSTRACT FROM AUTHOR]

We previously demonstrated that AA inhibited ENaC in the CCD and that the effect of AA was mediated by the cytochrome 450 (CYP) epoxygenase-dependent metabolic pathway because 11:12-EET mimicked the effect of AA on ENaC (JGP, 124:719, 2004). In the present study, we examined the effect of AA on ENaC in the CCD from rats on a high K diet (HK). Application of AA inhibited ENaC and the effect of AA was abolished by MS-PPOH, an inhibitor of CYP epoxygenase. The dose response curve of the AA effect on ENaC shows that the sensitivity of ENaC to AA in the CCD from rats on HK is shifted to the left in comparison to those on a low Na diet for 3 days. In contrast, the dose response curve of the AA effect in the CCD from rats on a low Na intake for 14 days was significantly shifted to the right. Western blot further shows that HK intake significantly increased while a low Na intake decreased the expression of CYP2C23 in the renal cortex and outer medulla. The possibility that increased sensitivity of ENaC to AA is due to a high expression of CYP epoxygenase is also confirmed by observation that the sensitivity of ENaC to 11,12-EET was the same among the three groups. We conclude that increased expression of CYP epoxygenase is responsible for the enhanced AA sensitivity of ENaC and that aldosterone is not responsible for mediating the stimulatory effect of HK on the expression of CYP2C23 because low Na intake, which increases aldosterone levels, did not mimic the effect of HK and suppressed the expression of CYP2C23. [ABSTRACT FROM AUTHOR]