Flavonifractor plautii Protects Against Elevated Arterial Stiffness.

BACKGROUND: Dysbiosis of gut microbiota plays a pivotal role in vascular dysfunction and microbial diversity was reported to be inversely correlated with arterial stiffness. However, the causal role of gut microbiota in the progression of arterial stiffness and the specific species along with the molecular mechanisms underlying this change remain largely unknown. METHODS: Participants with elevated arterial stiffness and normal controls free of medication were matched for age and sex. The microbial composition and metabolic capacities between the 2 groups were compared with the integration of metagenomics and metabolomics. Subsequently, Ang II (angiotensin II)-induced and humanized mouse model were employed to evaluate the protective effect of Flavonifractor plautii (F plautii) and its main effector cis-aconitic acid. RESULTS: Human fecal metagenomic sequencing revealed a significantly high abundance and centrality of F plautii in normal controls, which was absent in the microbial community of subjects with elevated arterial stiffness. Moreover, blood pressure only mediated part of the effect of F plautii on lower arterial stiffness. The microbiome of normal controls exhibited an enhanced capacity for glycolysis and polysaccharide degradation, whereas, those of subjects with increased arterial stiffness were characterized by increased biosynthesis of fatty acids and aromatic amino acids. Integrative analysis with metabolomics profiling further suggested that increased cis-aconitic acid served as the main effector for the protective effect of F plautii against arterial stiffness. Replenishment with F plautii and cis-aconitic acid improved elastic fiber network and reversed increased pulse wave velocity through the suppression of MMP-2 (matrix metalloproteinase-2) and inhibition of MCP-1 (monocyte chemoattractant protein-1) and NF-κB (nuclear factor kappa-B) activation in both Ang II-induced and humanized model of arterial stiffness. CONCLUSIONS: Our translational study identifies a novel link between F plautii and arterial function and raises the possibility of sustaining vascular health by targeting gut microbiota.

Consumption Patterns of Sugar-Sweetened Beverages and Association with Undernutrition among Children Aged 9-17 Years in Guangzhou, China: A Cross-Sectional Study.

Globally, the high consumption levels of sugar-sweetened beverages (SSBs) and their effect on health have drawn significant attention. This study aimed to identify the consumption patterns of SSBs among children in rural areas of Guangzhou, China, and explore their association with undernutrition. A total of 1864 children aged 9-17 years old were included in this study. Demographics, lifestyle behaviors, and anthropometric and dietary information were collected. Factor analysis was used to identify patterns of SSBs, while nutritional status was assessed using Body Mass Index (BMI). Latent class analysis was used to establish dietary preference models. Log-binomial regression analysis was used to analyze the association between SSBs consumption patterns and undernutrition. The undernutrition prevalence in children was 14.54-19.94% in boys and 9.07% in girls. Three SSB consumption patterns were identified, including the plant protein pattern, dairy-containing pattern, and coffee pattern. Both medium-high (Q3) and the highest (Q4) scores in the dairy-containing pattern were positively associated with the risk of undernutrition, especially in boys. Furthermore, the highest scores in the plant protein pattern and coffee pattern were positively associated with the risk of undernutrition in children aged 9-10 years old. The dairy-containing pattern was a risk factor for undernutrition in children, especially for boys; the plant protein patterns and coffee patterns were risk factors for undernutrition in children aged 9-10 years old. The findings of the study can provide scientific evidence and policy recommendations for improving children's health conditions.

Dietary patterns and association with Iron deficiency among children and adolescents aged 9-17 years in rural Guangzhou, China: a cross-sectional study.

Background: Iron deficiency and iron deficiency anemia cause a huge disease burden worldwide. Diet is an important factor affecting the iron levels. This study aims to explore the dietary patterns of school-aged children in rural areas of Guangzhou and their association with iron deficiency. Methods: Data on dietary surveys, lifestyle, demographic and laboratory tests were gathered from rural school-age children in Guangzhou. Factor analysis was applied to derive dietary patterns. Robust Poisson regression and subgroup analysis were used to analyze the association between dietary patterns and iron deficiency. Results: A total of 2,530 children and adolescents aged 9-17 years were enrolled. The prevalence of iron deficiency was 13.36%. Four dietary patterns were identified including snack and fast-food pattern, fruit and vegetable pattern, cereal and tuber pattern and meat and offal pattern. Both children and adolescents in the Q4 group (the highest propensity) of snack and fast-food pattern and cereal and tuber pattern had a higher risk of iron deficiency than the Q1 group (the lowest propensity). Both children and adolescents in the Q4 group of meat and offal pattern and fruit and vegetable pattern had a lower risk of iron deficiency than the Q1 group. The results of stratified analysis showed the negative effect of snack and fast-food pattern and the protective benefits of meat and offal pattern are more obvious for boys, and the negative effect of cereal and tuber pattern were obvious for girls. The negative effect or protective benefits of the four dietary patterns were obvious for children aged 9-13. Conclusion: Females, older children, and those with shorter sleep duration are at higher risk of iron deficiency. Snack and fast-food pattern and cereal and tuber pattern are risk factors for iron deficiency, and fruit and vegetable pattern and meat and offal pattern are protective factors for iron deficiency. The impact of diet on body iron levels is more obvious in boys and younger children. The findings of this study can provide evidence for formulating prevention and control measures on children and adolescents iron deficiency and iron deficiency anemia.

[The clinical patterns and RET proto-oncogene identification of pheochromocytoma in 13 multiple endocrine neoplasia type 2A pedigrees].

OBJECTIVE: To explore the clinical patterns and clinical significance for RET screening in adrenal pheochromocytoma (PHEO) associated with multiple endocrine neoplasia type 2A (MEN2A). METHODS: The clinical data of 32 PHEO patients with MEN2A from 13 unrelated MEN2A pedigrees from August 1989 to January 2013 were analyzed. The comprehensive medical data included systemic examinations and germline RET gene screening. RESULTS: Among 68 patients belonging to 13 MEN2A families, 32 (47.1%) presented with PHEO. There were 19 males and 13 females with a mean age of (41 ± 12) years. And the mean maximum diameter of PHEO was (4.6 ± 2.2) cm. The diagnosis of PHEO was made after medullary thyroid carcinoma (n = 12, 37.5%), simultaneously (n = 12, 37.5%), initially (n = 7, 21.9%) and death during appendectomy for PHEO-induced hypertensive crisis (n = 1, 3.1%). The diagnosis of PHEO was made before (n = 22) or after (n = 10) clinical screening. The former had 12 symptomatic cases while the latter only 1 case (12/22 vs 1/10, P = 0.024).Except for 5 asymtomatic fatal cases during non-PHEO operations, bilateral PHEO was found in 17 cases including 3 unilaterally treated cases developing another PHEO in contralateral adrenal with a lag period of 5, 10 and 17 years. There were 7 symptomatic patients in bilateral cases versus 6 in unilateral cases (7/17 vs 6/10, P = 0.440). Twenty-five patients underwent PHEO surgery: laparascopic approach in 14 cases (8 with bilateral simultaneous adrenalectomy) and open approach in 11 (2 with bilateral simultaneous adrenalectomy). And 10 patients undergoing bilateral adrenal-sparing operations or adrenalectomy required hormonal replacement therapy. During a mean observation period of 72 (1-282) months, no local recurrence, distant metastasis or Addisonian crisis were noted in 25 cases (contralateral relapse in 3 cases). Among them, 2 cases developed adrenocortical insufficiency unresponsive to an adjustment of hormonal doses.RET screening showed 4 recurrent missense substitutions in 32 MEN2A-PHEO patients: p. C634Y exon 11 (n = 27, 84.4%), p. C634R exon 11 (n = 3, 9.4%), p. C634F exon 11 (n = 1, 3.1%) and p. C618R exon 10 (n = 1, 3.1%). CONCLUSIONS: The mutations of RET proto-oncognene of PHEO in MEN2A are frequently located at codon 634. A combination of pedigree examination and RET gene screening may facilitate an early diagnosis and early treatment of asymptomatic PHEO patients in MEN2A.Laparoscopic cortical-sparing adrenalectomy for preserving adrenocortical function is a preferred surgical approach.

[Overexpression of circ_LARP4 inhibits the proliferation and migration of MCF-7 human breast cancer cells and its mechanism].

Objective To investigate the effect of overexpression of circRNA La-associated protein 4 (circ_LARP4) on malignant biological behaviors of MCF-7 breast cancer cells. Methods MCF-7 cells were transfected with circ_LARP4 plasmid pcDNA-circ_LARP4, and the expression of circ_LARP4 was detected by real-time quantitative PCR(qRT-PCR). After circ_LARP4 overexpression, CCK-8 assay was used to detect the proliferation of MCF-7 cells, and mRNAs of ki67, p21, inducible nitric oxide synthase (iNOS) and interleukin-1ß (IL-1ß) were detected by qRT-PCR. The bullet volume of tumor stem cells was observed under microscope, and the number of invaded cells was detected by TranswellTM assay. The expressions of octamer binding transcription factor 4(OCT4), SRY-related high-mobility-group box gene 2 (SOX2), vascular endothelial growth factor (VEGF), epithelial cadherin (E-cadherin) and neural cadherin (N-cadherin) were detected by Western blot. The levels of iNOS and IL-1ß in the supernatant of MCF-7 cells were detected by ELISA. Results Compared with the control group, circ_LARP4 overexpression group showed an upregulation in the expression of circ_LARP4, decreased cell proliferation, and down-regulated expression of ki67. It also reported the up-regulated expression of p21, smaller tumor stem cell bullet size, and decreased the expression of OCT4 and SOX2, together with the decreased number of invaded cells, decreased expression of VEGF and N-cadherin, increased expression of E-cadherin, and decreased levels of iNOS and IL-1ß. Conclusion Overexpression of circ_LARP4 inhibits the proliferation, invasion and stem cell-like characteristics of MCF-7 breast cancer cells, and down-regulates the levels of iNOS and IL-1ß.

Sleep Factors in Relation to Metabolic Dysfunction-Associated Fatty Liver Disease in Middle-Aged and Elderly Chinese.

CONTEXT: Accumulating evidence implies that sleep disturbance is involved in metabolic disorders. OBJECTIVE: We comprehensively evaluated the association between various dimensions of sleep behaviors and the risk for metabolic dysfunction-associated fatty liver disease (MAFLD). METHODS: In this cross-sectional study of 5011 participants with self-reported sleep behaviors and radiologically diagnosed MAFLD, a comprehensive healthy sleep score was generated to evaluate the associations between sleep behaviors and MAFLD risk using multivariate logistic regression adjusting for demographics, lifestyles, medication, and metabolic comorbidities. Furthermore, mediation analysis was utilized to assess the extent to which obesity explains the effect of sleep quality on MAFLD risk. RESULTS: Late bedtime, snoring, and daytime napping for over 30 minutes significantly associated with an increased risk of MAFLD, with odds ratios (OR) of 1.37 (95% CI 1.10, 1.70), 1.59 (95% CI 1.33, 1.91), and 1.17 (95% CI 1.02, 1.35), respectively, after full adjustments including obesity. Participants with disturbance in nighttime sleep and prolonged daytime napping showed the highest risk for MAFLD (OR 2.38, 95% CI 1.73, 3.27). Each additional increase of healthy sleep score was associated with a 16% reduction in MAFLD risk. Further stratified analysis revealed that people with a sedentary lifestyle and central obesity experienced more prominent adverse effects from poor sleep quality than others. Moreover, obesity accounted for only 20.77% of the total effect of sleep quality on MAFLD risk. CONCLUSIONS: Sleep behaviors, both cumulatively and individually, are associated with MAFLD risk. Public health awareness and strategies should be encouraged to curb MAFLD.

Intermittent Fasting Improves Cardiometabolic Risk Factors and Alters Gut Microbiota in Metabolic Syndrome Patients.

CONTEXT: Intermittent fasting (IF) is an effective strategy to improve cardiometabolic health. OBJECTIVE: The objective of this work is to examine the effects of IF on cardiometabolic risk factors and the gut microbiota in patients with metabolic syndrome (MS). DESIGN AND SETTING: A randomized clinical trial was conducted at a community health service center. PATIENTS: Participants included adults with MS, age 30 to 50 years. INTERVENTION: Intervention consisted of 8 weeks of "2-day" modified IF. MAIN OUTCOME MEASURE: Cardiometabolic risk factors including body composition, oxidative stress, inflammatory cytokines, and endothelial function were assessed at baseline and at 8 weeks. The diversity, composition, and functional pathways of the gut microbiota, as well as circulating gut-derived metabolites, were measured. RESULTS: Thirty-nine patients with MS were included: 21 in the IF group and 18 in the control group. On fasting days, participants in the IF group reduced 69% of their calorie intake compared to nonfasting days. The 8-week IF significantly reduced fat mass, ameliorated oxidative stress, modulated inflammatory cytokines, and improved vasodilatory parameters. Furthermore, IF induced significant changes in gut microbiota communities, increased the production of short-chain fatty acids, and decreased the circulating levels of lipopolysaccharides. The gut microbiota alteration attributed to the IF was significantly associated with cardiovascular risk factors and resulted in distinct genetic shifts of carbohydrate metabolism in the gut community. CONCLUSION: IF induces a significant alteration of the gut microbial community and functional pathways in a manner closely associated with the mitigation of cardiometabolic risk factors. The study provides potential mechanistic insights into the prevention of adverse outcomes associated with MS.

Prevalence and risk factors of metabolic associated fatty liver disease in the contemporary South China population.

BACKGROUND: As a newly proposed diagnosis, data on the prevalence of metabolic dysfunction-associated fatty liver disease (MAFLD) is rare. We aimed to assess the prevalence and risk factors of MAFLD using new definition in the contemporary South China population. METHODS: In this population based, cross sectional study, a total of 5377 participants aged 30-79 years old were recruited from the South China between 2018 and 2019. MAFLD was diagnosed in subjects who have both hepatic steatosis and metabolic disorders according to the newly international expert consensus. The total prevalence of MAFLD and prevalence by sex and age was estimated. Demographic characteristics, history of disease, and lifestyle were recorded by participants on a questionnaire. Abdominal ultrasonography was performed and evaluated by experienced sonographers. Multivariable logistic regression was used to calculate the odds ratios (ORs) of MAFLD. RESULTS: Overall prevalence of MAFLD was 29.2% (95% confidence interval [CI] 28.0% to 30.5%). Prevalence was higher in women (31.7%) than in men (25.5%; p < 0.001 for sex difference) and in subjects aged 50 years or older (30.7%) than in those aged 30-49 years (19.8%; p < 0.001 for age difference). In participants diagnosed with MAFLD, the prevalence of overweight/obesity was up to 90.5%, type 2 diabetes (T2DM) and metabolic dysregulation were 25.0% and 62.2%, respectively. Risk factors for MAFLD included overweight/obesity (OR = 4.67; 95% CI, 3.76-5.83), T2DM (OR = 2.41, 95% CI, 1.68-3.47), hypertriglyceridemia (OR = 2.42, 95% CI, 2.03-2.87), high school education (OR = 1.50, 95% CI, 1.23-1.82), high income (OR = 1.22, 95% CI, 1.05-1.42). A lower risk of MAFLD was associated with high physical activity equivalent (OR = 0.71, 95% CI, 0.60-0.85). A U-shaped association of frequency of soups and ORs of MAFLD was found, the adjusted ORs (95% CI) of lower and higher frequency of soups were 1.58 (1.32-1.89) and 1.36 (1.13-1.63), respectively. CONCLUSIONS: Our results showed a high prevalence of MAFLD in the general adult population in South China. Obesity has the greatest impact on MAFLD, physical activity and moderate consumption of soups might be the potential protective factors of MAFLD.

[Morphological characteristics in corneal smear of acanthamoeba keratitis].

OBJECTIVE: To study the morphological characteristics in corneal smear of acanthamoeba keratitis. METHODS: Experimental study. From May 1991 to December 2007, in Department of Microbiology, Beijing Institute of Ophthalmology, Beijing Tongren Hospital, 159 cases with acanthamoeba keratitis were analyzed for the laboratory results and clinical data. Giemsa's stained smear and wet-mount preparation of 159 cases were observed, all the results of cytology be photographed as the records. RESULTS: Among the 159 cases with acanthamoeba keratitis, 131 patients (82.4%) were positive on smear, and 110 cases (69.2%) were positive in culture of amoeba. The detection positive rate of smear was apparently higher than culture. Typical trophozoites, pre-encystment trophozoites, mature cysts and empty cysts could be observed by smear. So it is an important method for the clinical diagnosis. The edema and dissolved corneal epithelial cells, exudate cells, arthrospores or chlamydoconidium of mycelial fungus, vacuoles, lipid droplet and medicine crystallization should be differentiated with the pathogen. The movement of trophozoites could mainly be observed through wet-mount preparation. CONCLUSION: The detection of typical features of trophozoites, pre-encystment trophozoites, mature cysts and empty cysts by corneal smear is important for the etiological diagnosis of acanthamoeba keratitis.

Circulating Retinol-Binding Protein 4 Is Inversely Associated With Pancreatic ß-Cell Function Across the Spectrum of Glycemia.

OBJECTIVE: The aim of this study was to examine the association of circulating retinol-binding protein 4 (RBP4) levels with ß-cell function across the spectrum of glucose tolerance from normal to overt type 2 diabetes. RESEARCH DESIGN AND METHODS: A total of 291 subjects aged 35-60 years with normal glucose tolerance (NGT), newly diagnosed impaired fasting glucose or glucose tolerance (IFG/IGT), or type 2 diabetes were screened by a standard 2-h oral glucose tolerance test (OGTT) with the use of traditional measures to evaluate ß-cell function. From these participants, 74 subjects were recruited for an oral minimal model test, and ß-cell function was assessed with model-derived indices. Circulating RBP4 levels were measured by a commercially available ELISA kit. RESULTS: Circulating RBP4 levels were significantly and inversely correlated with ß-cell function indicated by the Stumvoll first-phase and second-phase insulin secretion indices, but not with HOMA of ß-cell function, calculated from the 2-h OGTT in 291 subjects across the spectrum of glycemia. The inverse association was also observed in subjects involved in the oral minimal model test with ß-cell function assessed by both direct measures and model-derived measures, after adjustment for potential confounders. Moreover, RBP4 emerged as an independent factor of the disposition index-total insulin secretion. CONCLUSIONS: Circulating RBP4 levels are inversely and independently correlated with ß-cell function across the spectrum of glycemia, providing another possible explanation of the linkage between RBP4 and the pathogenesis of type 2 diabetes.

[Mutant prevention concentrations of antibacterial agents to ocular pathogenic bacteria].

OBJECTIVE: To establish a method to measure mutant prevention concentration (MPC) in vitro, and to measure MPC of antibacterial agents for ocular bacteria caused keratitis. METHODS: It was an experimental study. Forty strains of ocular bacteria were separated from cornea in Beijing Institute of Ophthalmology, which included 8 strains of Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pneumoniae, Pseudomonas aeruginosa and Klebsiella pneumoniae respectively. The minimal inhibitory concentration (MIC) of the levofloxacin (LVF), ofloxacin (OFL), ciprofloxacin (CIP), norfloxacin (NFL), tobramycin (TOB) and chloromycetin (CHL) were determined by agar dilution method from National Committee of Clinical Laboratory Standard (NCCLS). The MPC were measured by accumulate-bacterial methods with bacterial population inoculated more than 1.2 x 10(10) colony forming units per milliliter with Mueller-Hinton broth and tryptic soy agar plate. With the software of SPSS 11.0, the datum such as the range of MIC, MPC, MIC90 and MPC90 were calculated, and the selection index (MPC90/ MI90) and mutant selection window (MSW) were obtained. RESULTS: The MI90 of LVF and TOB (4 mg/L) to Staphylococcus aureus strains were the lowest. CIP showed the lowest MIC90 (0.25 mg/L) to Pseudomonas aeruginosa among six kinds of antibacterial agents. The MIC90 of LVF to Staphylococcus epidermidis (256 mg/L), Streptococcus pneumoniae (1 mg/L) and Klebsiella pneumoniae (0.25 mg/L) were lower than other antibacterial agents. The MPC90, MSW and the MPC90/MIC90 of levofloxacin showed lower values compared with other antibacterial medicines. From all the datum, the MIC90 of CHL was the highest and the activity was the weakest. Although the activity of LVF was higher to every kind of bacteria, CIP had the highest activity antibacterial to Pseudomonas aeruginosa. The capacity of CHL and TOB was weaker than Quinolones for restricting resistant mutants on ocular bacteria. LVF had the strongest capacity for restricting resistant mutants among Quinolones. CONCLUSION: LVF has better antibacterial effects and stronger capacity for restricting the selection of resistant mutants on ocular bacteria than other antibacterial agents.

[Etiological analysis of ocular non-viral microbial isolates in children and their antibiotics susceptibility in vitro].

OBJECTIVE: To analyze the types, distribution characteristics and in vitro susceptibility of antibiotic agents of ocular non-viral microbial isolates in children. METHODS: Experimental research.785 specimens obtained from children below the age of 14 in Beijing Tongren Hospital during 1999 to 2004 were cultured and identified for bacterium, fungus and Acanthamoeba respectively at Beijing Institute of Ophthalmology. Microbial culture-positive rate, susceptibility patterns and the organisms distribution of positive cultures were retrospectively analyzed. The results were statistical analyzed by chi(2). RESULTS: Of the 785 specimens, 211 were culture positive. The percentage of positive culture was 26.88%. Of those positive cultures, 176 (83.41%) had pure bacterial infections, 32 (15.17%) had pure fungal infections, and 3 (1.42%) had pure cultures of Acanthamoeba. Of the 176 bacterial positive cultures, polymicrobial infection was present in 38 cases (33 bacterial, 5 fungal and bacterial). Of 214 bacterial isolates, the most common isolate was Neisseria gonorrhoeae (39/214, 18.22%), followed by Staphylococcus epidermidis (37/214, 17.29%), and Corynebacterium spp. (36/214, 16.82%). The most common fungal pathogen isolated was Fusarium spp. representing 25.00% (8/32) of all positive fungal cultures, followed by Aspergillus spp. (15.63%, 5/32). The sensitivity of tobramycin, norfloxacin, gentamicin, amikacin, ciprofloxacin, ofloxacin, rifampicin and levofloxacin of bacteria was 62.57%, 64.94%, 70.06%, 70.87%, 71.19%, 73.89%, 85.80% and 87.50%. Gram-positive isolates were susceptible to levofloxacin. Gram-negative isolates showed high susceptible to ciprofloxacin, ofloxacin and levofloxacin. The fungal isolates were most susceptible to natamycin, followed by terbinafine, but resistant to fluconazole. CONCLUSIONS: Bacteria are the most common pathogens in non-viral microbial eye infection in children. Neisseria gonorrhoeae, Staphylococcus epidermidis, and Corynebacterium spp. are the most common bacterial pathogens, which are highly susceptible to levofloxacin and rifampicin. Fusarium spp. and Aspergillus spp. are the most common fungal pathogens, which are highly susceptible to natamycin but resistant to fluconazole.

The antibacterial efficacy of an aceraceous plant [Shantung maple (Acer truncatum Bunge)] may be related to inhibition of bacterial beta-oxoacyl-acyl carrier protein reductase (FabG).

Polyphenols, including flavonoids, are the major components of the extracts from aceraceous plants. They possess remarkable antibacterial and antitumour activity. Our study focused on whether the inhibition of the bacterial type II fatty acid synthesis system is the mechanism for the antibacterial effect of the related plant polyphenols. Extracts obtained from the fallen leaves of the Shantung maple (Acer truncatum Bunge) using different solvents, and the related pure compound PGG (1,2,3,4,6-penta-O-galloyl-beta-D-glucose), potently inhibited the FabG (beta-oxoacyl-ACP reductase) steps in the fatty-acid-elongation cycle with the IC(50) values between 0.9 and 7.2 microg/ml. An ethyl acetate extract appeared to inhibit FabG reductase in a mixed manner with NADPH, as did PGG with NADPH, demonstrating that they interfered with the binding of the cofactor to the enzyme. Gram-positive and Gram-negative bacteria and some fungi were used to evaluate the antibacterial abilities of different extract samples. The experiments showed that a higher polyphenol content of the extracts led to a more potent inhibitory capacity against FabG, thus enhancing the antibacterial efficacy.

[Ultrastructure study of pathogen of acanthamoeba keratitis].

OBJECTIVE: To observe the ultrastructure of the strains of acanthamoeba isolated from acanthamoeba keratitis (AK), the morphologic changes of acanthamoeba after culture with 0.02% chlorhexidine, and ultrastructure characteristics of acanthamoeba in corneal tissue of AK. METHODS: It was a experimental study. The ultrastructure of acanthamoeba strains cultured with 0.02% chlorhexidine was observed with scanning electron microscope (SEM). The excited cornea tissues from AK were observed with transmission electron microscope (TEM). RESULTS: Cultured acanthamoeba trophozoites were approximately 15 - 45 microm in diameter, appeared irregularly round or oval in shape, with rough surface and intrusion of cytoplasm. The trophozoite propagated by ways of binary division. The acanthamoeba cysts were approximately 10 - 25 microm in diameter, round in shape and with a plica-like surface. The acanthamoeba could change from trophozoite to cyst. The amoeba emerging through ostioles could turn into trophozoite and left an empty cyst. After cultured with 0.02% chlorhexidine for 24 hours, the trophozoite and cyst collapsed and distorted. However, after clinical treatment with 0.02% chlorhexidine, only the cysts could be seen in corneal tissue of AK. Ecto-and endo-cystic walls were preserved, but the cytoplasma was aggregated and the sub-cytoarchitecture were degenerated or disappeared. DISCUSSION Chlorhexidine at a concentration of 0.02% kills acanthamoeba trophozoites and cysts in vitro. Chlorhexidine (0.02%) also kills trophozoites and inhibits the activity of cysts in corneal tissues. However, it should be noticed that the inactive cysts can stay in the cornea for a long time and may cause an immuno-pathologic inflammation of the cornea.

[Analysis on susceptibility of ocular bacterial pathogens to four kinds of fluoroquinolone].

OBJECTIVE: To assess the in vitro susceptibilities of ocular bacterial isolates to Gatifloxacin and other fluoroquinolones which are often used in ophthalmic treatment. METHODS: Non-randomized, non-comparative, retrospective study. Ocular bacterial isolates (n = 619) from Beijing Institute of Ophthalmology were tested for their susceptibilities to gatifloxacin, ciprofloxacin, ofloxacin and levofloxacin in vitro by the Kirby-Bauer disk diffusion method. RESULTS: The total number of ocular bacterial isolates was 619 from January, 2005 to December, 2006 including gram-positive cocci 372(60.1%), gram-negative cocci 7 (1.1%), gram-positive bacilli 60 (9.7%), gram-negative bacilli 177 (28.6%), other 3 (0.5%). The percentage of susceptibility in total ocular bacterial isolates to gatifloxacin, ciprofloxacin, ofloxacin and levofloxacin was 88.4%, 72.1%, 64.8% and 54.4%. The susceptibility of Staphylococcus species to gatifloxacin (89.9%) was significantly higher than ciprofloxacin (38.8%), ofloxacin (48.2%) and levofloxacin (61.6%). Streptococcus species showed significantly higher susceptibility to gatifloxacin (93.2%), levofloxacin (89.2%) and ofloxacin (87.8%) than ciprofloxacin (62.2%). The susceptibility of gram-positive bacilli to gatifloxacin (86.7%) was significantly higher than ciprofloxacin (58.3%); All above differences are significant (P < 0.0083). Gram-negative cocci, enteric bacilli family and Pseudomonas species have the equivalent susceptibility to gatifloxacin, ciprofloxacin, ofloxacin and levofloxacin (P > 0.05). CONCLUSIONS: Most of ocular bacterial are susceptible to gatifloxacin in vitro, especially gram-positive bacteria including Staphylococcus species, Streptococcus species and gram-positive bacilli.

Ocular nocardiosis: HSP65 gene sequencing for species identification of Nocardia spp.

PURPOSE: To assess hsp65 gene sequencing for detection and species identification of genus Nocardia from ocular isolates. DESIGN: A prospective study based on laboratory investigation. METHODS: Genus-specific hsp65 gene sequencing was used to identify the genus Nocardia isolated from 11 consecutive cases of ocular nocardiosis to the species level. RESULTS: Eleven eye clinical isolates belong to six species: N. arthritidis (3/11), N. neocaledoniensis (3/11), N. asiatica (2/11), N. asteroids type 4 (1/11), N. brasiliensis (1/11), and N. pseudobrasiliensis (1/11). N. arthritidis is the most important etiologic species that causes Nocardia keratitis. N. neocaledoniens is isolated in the conjunctiva, and might cause conjunctivitis. CONCLUSIONS: Genus-specific hsp65 gene sequencing can be a rapid and reliable adjunct in the diagnosis of ocular Nocardia to the genus and species level. N. arthritidis other than N. asteroids (often appeared in surveys) is the most important etiologic species in ocular nocardiasis. N. neocaledoniensis can be isolated in conjunctiva, and might be able to cause conjunctivitis. The diversity of species has important implications for the etiology, pathogenesis, and treatment (drug susceptibility).

[Experimental study of non-tuberculous mycobacterial keratitis in rabbits].

OBJECTIVE: To study clinical manifestation and pathology change of different time points of rabbit keratitis caused by non-tuberculous mycobacteria (NTM). METHODS: Forty-eight eyes from 48 rabbits were randomly divided into three groups:under-flap infection group (UFI group), under-flap infection group with corticosteroid (UFIC group) and surface infection group (SI group). The cornea infiltration area of all rabbits was observed. Bacterial quantitative culture and histopathological examination were performed. RESULTS: In the earliest stage (5 days), the cornea was cloudy and edematous. In the middle stage (7 - 14 days), cornea stromal infiltration became its major clinical sign. In the last stage (21 days), corneal neovascularization and fibrosis were developed. The mean stromal infiltration area in UFIC group was greater than those of UFI group and SI group (F = 9.362, 8.341, P < 0.05). The number of NTM in UFIC group was higher than those of UFI group and SI group (F = 411.272, P < 0.05). In histopathological examination, there were infiltrates with polymorphonuclear leukocytes (PMN) in the corneal stroma in the early stage and acid-fast bacilli was found. A plenty of lymphocytes in the cornea was found in the middle stage of NTM keratitis. In the latter stage, the fibroblast cells proliferation and corneal ulcer were cured. During the course of this infection, the number of CD4+, CD8+ T lymphocyte increased significantly, and then decreased gradually following the regress of the infection. In the stage (5 - 21 days), CD4+ T lymphocyte decreased significantly in UFIC group compared with other two groups (F = 21.907, 196.521, 12.552, 11.100, P < 0.01). CONCLUSIONS: The clinical characteristic of rabbit keratitis is the multifocal dense superficial stromal infiltrates. CD4+ T lymphocyte may play an important role in NTM keratitis.

[Etiological analysis on bacterial endophthalmitis].

OBJECTIVE: To investigate the spectrum of organisms causing bacterial endophthalmitis and their sensitivities to commonly used ocular antibiotics. METHODS: A retrospective analysis on microbiological records of 728 intraocular specimens of patients with suspected endophthalmitis from January 1999 to December 2006. Antibiotic susceptibility of these isolates was determined for commonly used ocular antibiotics using the Kirby-Bauer disk-diffusion test. RESULTS: In all, 168 organisms were isolated from 728 intraocular specimens during the study interval. Overall, 96 (57.1%) of 168 isolates were Gram-positive cocci, 52 (31.0%) were Gram-negative bacilli, 18 (10.7%) were Gram-positive bacilli, and 2 (1.2%) were Gram-negative cocci. The most common organisms identified were Staphylococcus epidermidis in 21.4% (36/168), Staphylococcus aureus in 11.3% (19/168), and Pseudomonas aeruginosa in 8.9% (15/168). For Gram-positive cocci, sensitivities were the following: vancomycin 93.4% (85/91), levofloxacin 84.4% (81/96), ofloxacin 68.8% (66/96), ciprofloxacin 59.4% (57/96), gentamicin 56.3% (54/96), and tobramycin 43.8% (42/96). For Gram-negative bacilli, sensitivities were the following: levofloxacin 88.2% (45/51), ofloxacin 76.9% (40/52), ciprofloxacin 75.0% (39/52), gentamicin 49.0% (25/51), and tobramycin 48.1% (25/52). Comparing the data from 2003 to 2006 with the data from 1999 to 2002, the susceptibility of organisms to frequently employed antibiotics was decreasing. CONCLUSIONS: The spectrum of organisms causing bacterial endophthalmitis is complex, and no single antibiotic provided coverage for all of the microbes isolated from intraocular specimens with bacterial endophthalmitis. Combination therapy is recommended as the initial empiric treatment of suspected bacterial endophthalmitis.

Acanthamoeba keratitis: clinical characteristics and management.

OBJECTIVE: To review the clinical characteristics, treatment, and outcome of patients with Acanthamoeba keratitis (AK). DESIGN: Retrospective, noncomparative, interventional case series. PARTICIPANTS: Twenty consecutive patients with AK were referred to the Beijing Tongren Hospital, Capital University of Medical Science, China. METHODS: Retrospective analysis of medical records from 20 consecutive patients with AK between December 1, 1997 and March 30, 2003. Risk factors, laboratory investigations, clinical manifestations, treatments, and outcomes were analyzed. MAIN OUTCOME MEASURES: Best-corrected visual acuity (BCVA) at the end of follow-up. RESULTS: Of the 20 patients presented in this series, 12 patients were students and 6 were farmers. Risk factors included contact lens wear (12/20) and trauma (6/20). Corneal ulceration, diffuse stromal infiltration, and ring infiltration were the main clinical manifestations. The diagnosis of all patients was based on the laboratory investigation. Smear and culture positive specimens were 19 of 20 and 12 of 20, respectively. Images of cysts were demonstrated with confocal microscopy in 4 patients. Treatment was combined instillation of chlorhexidine (0.02%), neomycin (0.5%), metronidazole (0.4%), and/or lesion cauterization with chlorhexidine (1%), and corneal lesion debridement. The mean duration of therapy was 70 days (range, 18-150 days). Nineteen lesions healed with scar formation. The BCVA was better or equal to 20/100 in 7 eyes. CONCLUSIONS: Early diagnosis of AK is the key challenge in clinical practice. The combined use of antiacanthamoeba agents, debridement, and cauterization may be a best choice of treatment for patients who are diagnosed early in the course of their disease.