Outcomes of post-cataract surgery endophthalmitis referred to a tertiary center from local hospitals in the south of China

BACKGROUND

Endophthalmitis after cataract surgery is an uncommon but devastating complication. Prophylactic intracameral injection of cefuroxime 1 mg at the end of surgery decreases the incidence five-fold. The visual outcome can be good (53% of cases having a visual acuity [VA] of better than 20/40) if treatment is initiated rapidly and follows the Endophthalmitis Vitrectomy Study (EVS) guidelines; but even with the best treatment, some patients end up with a poor visual outcome. Previous studies on postoperative endophthalmitis mainly focus on the cases performed in metropolitan tertiary hospitals; however, little information is available on the cases performed in local hospitals in rural areas.

METHODS

We retrospectively reviewed the medical records of patients with acute endophthalmitis following cataract surgery, which were performed in local hospitals and later treated at the Zhongshan Ophthalmic Center between 1 January 1998 and 31 December 2009. Details of each case, including the interval from symptoms to presentation, initial treatment in local hospitals, microorganisms isolated, treatment, and visual outcome, were recorded. Cross-tabulations were conducted in order to identify the prognostic factors of final visual outcome.

RESULTS

Forty-six patients referred from 36 local hospitals and later treated at the Zhongshan Ophthalmic Center were reviewed over the audit period. Most of these cases occurred in April. Gram-positive bacteria were the predominant etiology, with fungal infection accounting for 15%. Even though 54% of patients had symptoms within 3 days post-cataract surgery, they did not present to a tertiary center until a mean of 10 days. The main initial treatment in local hospitals is systemic antibiotics, instead of the intravitreal injection of antibiotics. A high proportion of cases (27/46) received immediate pars plana vitrectomy (PPV) in the tertiary center, and the antibiotic used for intravitreal injection was mainly tobramycin. The final visual outcome was poor, with only three cases having a VA ≥20/40.

CONCLUSION

A relatively high rate of fungal endophthalmitis suggests that sterilization patterns in local hospitals should be further revised. A delayed presentation, inappropriate treatment procedures, poor presenting VA, and causative organism virulence may account for the unfavorable visual outcome in this study.

Collagen triple helix repeat containing-1 inhibits transforming growth factor-b1-induced collagen type I expression in keloid

BACKGROUND

Keloids are benign skin tumours occurring during wound healing in genetically predisposed patients. There is evidence that transforming growth factor (TGF)-b is involved in keloid formation. Collagen triple helix repeat containing- 1 (Cthrc1) was identified as a novel gene expressed in the adventitia and neointima on arterial injury. It is indicated to be a cell type-specific inhibitor of TGF-b, which functionally increases cell migration while reducing collagen type I and III deposition. However, to our knowledge expression and regulatory mechanisms of Cthrc1 and TGF-b1 in keloid and normal skin have not been studied before.

OBJECTIVES

Cthrc1 gene regulation and potential role in keloid formation were determined, and its correlation with TGF-b1 involved in keloid pathogenesis was examined in human fibroblasts of keloids and normal skin.

METHODS

The expression of Cthrc1 and TGF-b1 was investigated in fibroblasts of keloid and normal skin. Collagen type I expression and collagen synthesis in keloid fibroblasts induced by TGF-b1 were examined. Then, recombinant Cthrc1 was applied to assess its correlation with TGF-b1.

RESULTS

Increased TGF-b1 and Cthrc1 expression was examined in keloid compared with normal skin. Cthrc1 expression increased in a concentration-dependent manner induced by TGF-b1 in keloid fibroblasts. TGF-b1 stimulated collagen type I expression and collagen synthesis in keloid fibroblasts, which can be reversed by recombinant Cthrc1.

CONCLUSIONS

TGF-b1 was upregulated in keloid fibroblasts and recombinant Cthrc1 inhibited TGF-b1-stimulated collagen type I synthesis, which suggests that Cthrc1 may be a potential therapeutic option for keloids.

Genotyping of Toxoplasma gondii isolates from cats in different geographic regions of China

Fourteen isolates of Toxoplasma gondii were isolated from cats from 4 different geographic provinces (Anhui, Hubei, Shanxi and Guangdong) in China and their genetic diversity with 8 nuclear loci SAG2, SAG3, BTUB, GRA6, L358, PK1, c22-8, c29-2, and an apicoplast locus Apico, was analysed by restriction fragment length polymorphisms (RFLPs). Two genotypes from these 14 isolates were identified but none of them belongs to the typical genetic types (types I, II and III). It is unexpected that such high similarity was observed in these 14 isolates although their original regions are significantly distant. Our results strongly indicate that the three traditional clonal lineages of types I, II and III of this parasite may not be preponderant in China. In addition, our results show that the genotypes of T. gondii in China may be highly clonal with atypical genotypes and higher virulence.

PLA2G6 gene mutation in autosomal recessive early-onset parkinsonism in a Chinese cohort

OBJECTIVE

Mutations in the PLA2G6 gene at the PARK14 locus have been reported in complicated parkinsonism. To assess the prevalence of and phenotypes associated with PLA2G6 gene mutations, we screened PLA2G6 mutations in a cohort of patients with autosomal recessive early-onset parkinsonism (AREP).

METHODS

We selected 12 families with AREP in which the Parkin, PINK1, DJ-1, ATP13A2, and FBXO7 gene mutations had been previously excluded. All patients came from the mainland of China. The entire PLA2G6 coding region and exon-intron boundaries were sequenced from genomic DNA templates. We then performed PET studies on individuals in the pedigree with a homozygous PLA2G6 mutation, and investigated the enzyme activity level of the mutation.

RESULTS

A homozygous missense mutation, c.G991T (p.D331Y), was identified in an autosomal recessive case. A younger sister of the p.D331Y-carrying patient was also homozygous for the mutation, but with no extrapyramidal symptoms. A PET study showed a substantial reduction in dopamine transporter (DAT) binding in the p.D331Y patient, and a slight reduction in DAT binding in his sister. In vitro, we experimentally demonstrate that the D331Y mutation caused an approximately 70%reduction in enzyme activity.

CONCLUSIONS

We have confirmed that the PLA2G6 gene allocated PARK14 locus and is associated with AREP.

Colitogenic role of tumour necrosis factor (TNF) receptors in trinitrobenzene sulphonic acid colitis: TNF-R1 ablation does not affect systemic inflammatory response

Tumour necrosis factor (TNF)-α plays a critical role in the pathogenesis of T helper type 1-mediated colitis such as Crohn's disease. However, the roles of its two receptors in mediating pathology remain largely unknown. In this study, trinitrobenzene sulphonic acid (TNBS) was used to induce colitis in TNF-receptor single or double knock-out (DKO) BALB/c mice and in wild-type counterparts. TNF-R1(-/-) mice had significantly less weight loss, reduced mortality, colon shortening and oedema, colon histological damage and lower levels of colon myeloperoxidase compared with wild-type (WT) BALB/c mice. A similar manifestation was also observed in TNF-R2(-/-) and TNF-R1(-/-) TNF-R2(-/-) (TNF-R DKO) mice. Strikingly, systemic inflammatory response (including splenomegaly and monocyte expansion) was found in WT and TNF-R1(-/-) mice after TNBS, instead of TNF-R2(-/-) and TNF-R DKO mice. Attenuated pathology of colitis in TNF-R1(-/-) or TNF-R2(-/-) mice correlated with lower amounts of interleukin (IL)-6, IL-1β, monocyte chemotactic protein (MCP)-1, IL-12p70 and interferon (IFN)-γ production in the colons. Importantly, ablation of TNF-R1 or TNF-R2 reduced the number of terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end-labelling (TUNEL)-positive apoptotic epithelial cells in the affected colons compared with WT TNBS-instilled controls, which might be due to the heightened ratio of Bcl-2/Bax and reduced activity of nuclear factor (NF)-κB. These findings suggest that either TNF-R1 or TNF-R2 plays a pathogenic role in the pathology of colitis and TNF signalling via TNF-R1 or TNF-R2 alone is not sufficient for inducing mucosal damage.

Radiation enhances long-term metastasis potential of residual hepatocellular carcinoma in nude mice through TMPRSS4-induced epithelial-mesenchymal transition

Recurrence and metastasis are frequently observed after radiotherapy for hepatocellular carcinoma (HCC), although upregulation of matrix metalloproteinases (MMPs) and vascular endothelial growth factor (VEGF) induced by radiation has been claimed to be involved, the mechanism is not clarified yet. In the present study, by using MHCC97L, a human HCC cell line with metastatic potential, and its xenograft in nude mice, we found that radiation induced a 48- to 72-h temporary increase in the expression of MMP-2 and VEGF both in vitro and in vivo, but only the in vitro invasiveness of MHCC97L cells was enhanced, while the in vivo metastatic potential of tumors was suppressed. Whereas, 30 days after radiation, when the expression of MMP-2 and VEGF decreased to unirradiated control levels, the in vivo dissemination and metastatic potential of residual tumors have just begun to increase with overexpression of TMPRSS4, which induced loss of E-cadherin through induction of Smad-Interacting Protein 1 (SIP1), an E-cadherin transcriptional repressor, and led to epithelial-mesenchymal transition (EMT). This process was blocked by treatment of siRNA-TMPRSS4. In conclusion, our study revealed novel findings regarding the biphasic effect of radiation on the metastatic potential of residual HCC. Overexpression of TMPRSS4 has a critical role in radiation-induced long-term dissemination and metastasis of residual HCC by facilitating EMT. These findings may provide new clues to suppress the radiation-induced dissemination and metastasis, thereby improve the prognosis of HCC patients.

Optical detection of spin transport in nonmagnetic metals

We determine the dynamic magnetization induced in nonmagnetic metal wedges composed of silver, copper, and platinum by means of Brillouin light scattering microscopy. The magnetization is transferred from a ferromagnetic Ni80Fe20 layer to the metal wedge via the spin pumping effect. The spin pumping efficiency can be controlled by adding an insulating interlayer between the magnetic and nonmagnetic layer. By comparing the experimental results to a dynamical macroscopic spin-transport model we determine the transverse relaxation time of the pumped spin current which is much smaller than the longitudinal relaxation time.