[Trans-ethnic analysis of susceptibility variants in IgA nephropathy].

OBJECTIVE: To compare the genetic architecture of susceptibility variants of IgA nephropathy (IgAN) in Chinese and Europeans. METHODS: We selected the independent genome-wide significant variants of IgAN in European population as candidate variants. Their associations, risk alleles, risk allele frequencies, odds ratios and population attributable risk scores were derived and calculated, then compared with those in the current Chinese population, including 1 194 IgAN patients and 902 controls. Using the significant variants, genetic risk scores were calculated and compared between the East Asians and the Europeans. The correlation between the genetic risk scores and clinical manifestations was also evaluated. RESULTS: There were 16 independent single nucleotide polymorphisms (SNPs) located in 11 loci showing significantly association with susceptibility to IgAN in the Europeans. 93.75% (15/16) of them also showed significant associations in the Chinese (P<0.05). The effects of all the associated SNPs were in the same direction, either risk or being protective for IgAN, between the Chinese and the Europeans. On the contrary, remarkable higher risk allelic odds ratio (P=1.94×10-2), higher risk allele frequency (P=3.09×10-2), and higher population attributable risk (P=3.03×10-4) were observed for most of the associated SNPs in the Chinese than in the Europeans. Furthermore, genetic risk scores were significantly larger in the Asian populations compared with the Europeans (P=1.78×10-163). While there was no significance among the subpopulations in both the East Asians and the Europeans. Compared with the healthy controls, the genetic risk score in the IgAN patients was significantly larger (P=3.60×10-27). Clinical analysis showed the genetic risk score was positively associated with serum levels of IgA and IgA1, phases of chronic kidney disease and Haas grades. CONCLUSION: Our study provides further evidence in the shared genetic architecture between Chinese and Europeans, while differences with respect to the effect sizes and risk allele frequencies across ethnicities, contributing partially to the differences of disease prevalence.

Ischemic post-conditioning attenuates the intestinal injury induced by limb ischemia/reperfusion in rats

The purpose of this study was to investigate the protective effects of ischemic post-conditioning on damage to the barrier function of the small intestine caused by limb ischemia-reperfusion injury. Male Wistar rats were randomly divided into 3 groups (N = 36 each): sham operated (group S), lower limb ischemia-reperfusion (group LIR), and post-conditioning (group PC). Each group was divided into subgroups (N = 6) according to reperfusion time: immediate (0 h; T1), 1 h (T2), 3 h (T3), 6 h (T4), 12 h (T5), and 24 h (T6). In the PC group, 3 cycles of reperfusion followed by ischemia (each lasting 30 s) were applied immediately. At all reperfusion times (T1-T6), diamine oxidase (DAO), superoxide dismutase (SOD), and myeloperoxidase (MPO) activity, malondialdehyde (MDA) intestinal tissue concentrations, plasma endotoxin concentrations, and serum DAO, tumor necrosis factor-α (TNF-α), and interleukin-10 (IL-10) concentrations were measured in sacrificed rats. Chiu’s pathology scores for small intestinal mucosa were determined under a light microscope and showed that damage to the small intestinal mucosa was lower in group PC than in group LIR. In group PC, tissue DAO and SOD concentrations at T2 to T6, and IL-10 concentrations at T2 to T5 were higher than in group LIR (P < 0.05); however, tissue MPO and MDA concentrations, and serum DAO and plasma endotoxin concentrations at T2 to T6, as well as TNF-α at T2 and T4 decreased significantly (P < 0.05). These results show that ischemic post-conditioning attenuated the permeability of the small intestines after limb ischemia-reperfusion injury. The protective mechanism of ischemic post-conditioning may be related to inhibition of oxygen free radicals and inflammatory cytokines that cause organ damage.

Ischemic post-conditioning attenuates the intestinal injury induced by limb ischemia/reperfusion in rats.

The purpose of this study was to investigate the protective effects of ischemic post-conditioning on damage to the barrier function of the small intestine caused by limb ischemia-reperfusion injury. Male Wistar rats were randomly divided into 3 groups (N = 36 each): sham operated (group S), lower limb ischemia-reperfusion (group LIR), and post-conditioning (group PC). Each group was divided into subgroups (N = 6) according to reperfusion time: immediate (0 h; T1), 1 h (T2), 3 h (T3), 6 h (T4), 12 h (T5), and 24 h (T6). In the PC group, 3 cycles of reperfusion followed by ischemia (each lasting 30 s) were applied immediately. At all reperfusion times (T1-T6), diamine oxidase (DAO), superoxide dismutase (SOD), and myeloperoxidase (MPO) activity, malondialdehyde (MDA) intestinal tissue concentrations, plasma endotoxin concentrations, and serum DAO, tumor necrosis factor-α (TNF-α), and interleukin-10 (IL-10) concentrations were measured in sacrificed rats. Chiu's pathology scores for small intestinal mucosa were determined under a light microscope and showed that damage to the small intestinal mucosa was lower in group PC than in group LIR. In group PC, tissue DAO and SOD concentrations at T2 to T6, and IL-10 concentrations at T2 to T5 were higher than in group LIR (P < 0.05); however, tissue MPO and MDA concentrations, and serum DAO and plasma endotoxin concentrations at T2 to T6, as well as TNF-α at T2 and T4 decreased significantly (P < 0.05). These results show that ischemic post-conditioning attenuated the permeability of the small intestines after limb ischemia-reperfusion injury. The protective mechanism of ischemic post-conditioning may be related to inhibition of oxygen free radicals and inflammatory cytokines that cause organ damage.

High rate of virus-free plantlet regeneration via garlic scape-tip culture.

Shoot cultures of Allium sativum L. were established from stem-tip and scape-tip. Various combinations of media, growth regulators were compared. The best establishment and proliferation of stem-tip and scape-tip explants were obtained on MS medium containing 0.5 mg l(-1) NAA and 0.5 mg l(-1) KT. The roots were produced and the bulblets were formed after the micro-shoots were transferred to the hormone-free MS medium. The virus of each tube-plant was detected by ELISA. The virus elimination rates of plantlets from stem-tip with 3 leaf primordia, with 1-2 leaf primordia, and scape-up were 26.5%, 45.4%, and 77.6% respectively. The procedure of scape-tip culture would be applied for virus elimination to the species propagated vegetatively.

Regeneration of haploid plants from isolated microspores of asparagus (Asparagus officinalis L.).

High percentages of micro-calli and micro-derived embryos were produced from isolated asparagus microspores at late uninucleate stage on MS liquid medium supplemented with 1.0 mg l(-1) 2,4-D and 0.5 mg l(-1) BA. Two types of calli, namely compact callus (CC) and loose callus (LC), were found. Plantlets were regenerated via organogenesis, when these calli were transferred onto MS solid medium supplemented with 1.0 mg l(-1) BA and 0.2 mg l(-1) IBA 6 weeks. Embryos were produced from liquid cultured microspores, or from solid cultured micro-calli. The frequencies of haploid plant production from organogenesis and embryogenesis were compared. Effects of plant growth regulators on callus production, plantlet regeneration, and haploid plant production were tested. The combination of BA 1.0 mg l(-1) and IBA 0.2 mg l(-1) resulted the highest precentage of haploid plant production (7.7% from CC, 4.3% from LC).

Ultrastructure of malignant Brenner tumor of the ovary.

Six malignant Brenner tumors of the ovary were studied electronmicroscopically. The histologic features of the tumors resemble to those of nonkeratinized squamous cell carcinoma of the uterine cervix. The ultrastructural features of malignant Brenner tumor included intracytoplasmic glands and cysts, presence of cilia, abundant glycogen, numerous desmosome-tonofilament complex, of which the cilium is most characteristic in the ovarian surface epithelium or Mullerian epithelium, but not in uroepithelium. Desmosome-tonofilament complex, the ultrastructure specific for the squamous epithelium, was not seen in the uroepithelium. We conclude that the appearance of cilium in malignant Brenner tumor indicates that the tumor is derived from the Mullerian epithelium, and that the presence of desmosome-tonofilament complex evidences that the tumor cells have differentiated into squamous epithelium. Our findings have proved that the malignant Brenner tumor arises from the Mullerian epithelium and recapitulates the vaginocervical epithelium.