Glial cell expression of hepatocyte growth factor in vitreoretinal proliferative disease

The hepatocyte growth factor (HGF) has been crucially implicated in the development of proliferative retinal diseases; however, it is unclear whether retinal glial cells express or respond to HGF. Therefore, we examined the expression of HGF and of the receptor for HGF, c-Met, by immunohistochemical costaining with glial fibrillary acidic protein (GFAP) in epiretinal membranes of patients with proliferative vitreoretinopathy (PVR) and proliferative diabetic retinopathy (PDR), respectively. Furthermore, it was determined whether cells of the human retinal glial cell line, MIO-M1, secrete HGF protein, and whether HGF stimulates proliferation and chemotaxis, and secretion of the vascular endothelial growth factor (VEGF). Neuroretinas of patients with PVR express elevated mRNA level for HGF in comparison to control retinas. In epiretinal membranes of patients with PVR or PDR, immunoreactivity for HGF and for c-Met, respectively, partially colocalized with immunoreactivity for GFAP. Fetal bovine serum and basic fibroblast growth factor, but not heparin-binding epidermal or platelet-derived growth factors, evoked HGF secretion by cultured retinal glial cells. HGF displayed only a marginal effect on cell proliferation while it stimulated chemotaxis. HGF promoted the secretion of VEGF, via activation of the phosphatidylinositol-3 kinase. It is concluded that glial cells in epiretinal membranes express both HGF protein and c-Met receptors. The results suggest an autocrine/paracrine role of HGF in glial cell responses during proliferative vitreoretinal disorders as well as in retinal neovascularization, by stimulating of VEGF release.     

真核表达人呼吸道合胞病毒F蛋白的纯化方法

目的 真核表达人呼吸道合胞病毒(human respiratory syncytial virus,SV)融合蛋白(fusion protein,),并完成蛋白纯化及纯度测定.方法 根据编码F蛋白的基因序列设计引物,CR方法扩增出3'端带His标签的F基因序列,克隆入pGEM-T-easy载体,经核酸序列分析后,进一步克隆到pcDNA3.1( )真核表达载体,限制性内切酶鉴定,用脂质体Lipofectamine2000转染COS-7细胞,2 h后再用Westem blot检测目的蛋白的表达.Ni柱亲和层析纯化COS-7细胞表达的F蛋白,高效毛细管电泳分析纯化后蛋白纯度.结果 核酸序列分析证实获得带His标签的RSV F基因序列,没有发生无义突变.转染COS-7细胞后,利用Western blot方法检测到F蛋白的特异性条带,纯度达99%以上.结论 初步建立了真核表达RSV F蛋白的纯化方法,为进一步优化RSV F蛋白制备条件及单克隆抗体及诊断试剂等研究奠定了基础.     

Nosocomial and community acquired uropathogenic isolates of Proteus mirabilis and antimicrobial susceptibility profiles at a university hospital in Sub–Saharan Africa

ObjectiveTo ascertain antimicrobial susceptibility profile of Proteus mirabilis (P. mirabilis) from clinical urine specimens at a university hospital in the spate of its recorded increasing resistance patterns.MethodsThe study was retrospective in nature. Data generated from urine cultures of patients at University of Calabar Teaching Hospital for a period of five years (2004–2009) were compiled. Relevant information obtained were age and gender of patients, organisms recovered and their antibiotic susceptibility patterns. P. mirabilis was identified using standard laboratory procedures.ResultsP. mirabilis showed the highest resistance against ampicillin, cloxacillin, amoxicillin, tetracycline, co-trimoxazole, erythromycin and chloramphenicol (100%–37.2%) while colistin, ofloxacin, ciprofloxacin, ceftriaxone, nalidixic acid and nitrofurantoin recorded the highest activity (59.1%–96.9%) with no drug recording 100% activity. The resistance of the nosocomial isolates of the organism were significantly higher than the community acquired isolates against that of the common antibiotics in use (P<0.05).ConclusionsExtreme caution should be exercised in antibiotic administration in hospital setting and the potential benefits adequately assessed while control of nosocomial infections be given a priority so as to limit the spread of resistant bacteria.     

Clinical findings in macular hole surgery with indocyanine green-assisted peeling of the internal limiting membrane

PURPOSE: Indocyanine green (ICG) staining of the internal limiting membrane has facilitated ILM peeling in macular hole surgery. However, it has been reported that ICG-assisted peeling of the ILM may result in retinal damage and unfavorable functional outcome. Therefore, we analyzed our visual and anatomical results of ICG assisted macular hole surgery. METHODS: In a retrospective study the records of a consecutive series of 37 patients with full-thickness idiopathic macular holes operated with ICG-assisted ILM peeling by a single surgeon were analyzed. All patients underwent a standard three-port vitrectomy with surgically induced posterior vitreous detachment, staining of the ILM with ICG, peeling of the ILM in a circular manner around the fovea, and SF6 20% endotamponade. RESULTS: A total of 37 patients (37 eyes) were included in the study. The mean age was 69+/-7 years (range 52-81 years), and there were 26 women and 11 men. The follow-up ranged from 6 to 30 months (mean 18+/-6 months). At baseline visual acuity ranged from 20/400 to 20/40. Anatomically, 13 eyes had stage 2 holes, 21 eyes (57%) stage 3 holes, and three eyes stage 4 holes. At the postoperative visit (8-12 weeks after surgery) anatomical closure of the macular hole was achieved in 36 eyes. Visual acuity ranged between 20/400 and 20/20. At the last follow-up after initial surgery the macular hole was closed in all eyes. Visual acuity ranged from 20/200 to 20/20. CONCLUSION: In our retrospective series anatomical and functional results of macular hole surgery with ICG-assisted peeling of the ILM are satisfactory. Primary hole closure was achieved in 97% of eyes and visual acuity increased in 62% of eyes in our series.     

Histological findings of surgically excised choroidal neovascular membranes after photodynamic therapy

AIM: To investigate effects of photodynamic therapy (PDT) on human choroidal neovascularisation (CNV). METHODS: Two patients with recurrences after PDT with verteporfin underwent surgical extraction of the CNV. Immediately after surgical excision the subfoveal neovascular membranes were divided for light microscopic and for electron microscopic processing. For light microscopy tissues were embedded in paraffin. Sections were stained with haematoxylin and eosin, and the periodic acid Schiff (PAS) reaction was performed to determine histological diagnosis and to ensure tissue quality. For electron microscopy the specimens were fixed in glutaraldehyde and embedded in epoxy resin. Semithin sections were stained with uranyl acetate and lead citrate and examined with a transmission electron microscope. RESULTS: Light microscopy showed thick fibrovascular membranes in both cases. On the outer surface remnants of retinal pigment epithelial cells resting on thickened inner aspect of Bruch's membrane were found. On the retinal side some outer segments were found. The membrane showed areas with irregularly shaped vessels. Electron photomicrographs showed occluded vessels within the CNV containing thrombotic masses and/or ultrastructural damage of the neovascular endothelium. Most of the vessels presented regressive changes with vacuolisation and fragmentation of the neovascular endothelium accompanied by disintegration of the endothelial cell layer. Extravasation of red blood cells was observed. Occasionally, vessels with normal endothelium containing intact red blood cells were observed. Some vessels contained immature endothelial cells. At some locations the retinal pigment epithelium cells (RPE) were metaplastic showing highly vacuolised cytoplasm. CONCLUSIONS: These findings suggest that the evidence of fluorescein leakage from the CNV and enlargement of the neovascular complex following PDT could be related to new vessel growth and recanalisation of occluded vessels. Additionally, RPE disturbances were observed in the specimens. This finding may be related to the original pathology or could indicate that PDT treatment may result in RPE atrophy.     

Quantity not composition of dietary fats represents the dominant contributor to experimental obesity: Relevance to human pathophysiology

Plant fats are low in saturated fats but high in unsaturated fats compared to animal fats, and are supposedly less obesogenic. This study compared the obesogenic effects of plant and animal derived fatty diets in Wistar rats. Rats of each gender were divided into three dietary (standard chow (SC), high fat diet rich in animal fat (HFDaf) and a high fat diet rich in plant fat (HFDpf)) groups of ten each and fed for 17 weeks. Anthropometric, Adiposity and nutritive variables were assessed using standard methods. Comparing HFDpf to HFDaf: Abdominal circumference (AC),initial feed intaken (IFI), final feed intake(FFI), final body weight (FBW), white adipose tissue (WAT) were increased but brown adipose tissue (BAT) decreased in male rats fed with HFDpf; also, there were increased body length, IFI, FFI but decreased AC, FBW, BAT in female rats fed with HFDpf. Comparing male to female rats: Thoracic circumference, IFI, FFI, energy intake were increased while Adiposity index decreased across diet groups in male rats; the AC, FBW increased while WAT, BAT decreased in HFDpf fed group, also, BAT was increased but AC, FBW decreased in HFDaf fed group in male rats. Palatability and high feed efficiency of consumed diets were more associated with obesogenic risk than just the level of saturation. Therefore, Obesogenic effects of fatty diets in both genders is more dependent on the quantity (amount) of fatty diet consumed than the dietary fat composition alone.     

Platelet-leukocyte interaction: selective binding of thrombin- stimulated platelets to human monocytes, polymorphonuclear leukocytes, and related cell lines

The association of platelets with leukocytes was investigated, using gel-filtered platelets stimulated with thrombin and then fixed with formaldehyde. Evidence is presented that stimulation of gel-filtered platelets with low concentrations of thrombin (0.01 to 0.1 U/mL) induces the expression of surface determinants interacting strongly with monocytes and polymorphonuclear leukocytes (PMNs) but only weakly with lymphocytes. Both monocyte-platelet binding and PMN-platelet binding occurred at 37 degrees C and more intensively at 0 degrees C; it was Ca2+-dependent and was unaffected by the addition of sodium azide. The binding also occurred with the monocytoid cell lines HL 60 and U 937 in exponential growth and was much less two days after induction of terminal differentiation by phorbol myristate acetate (PMA). No other tested cell lines (B cells, T cells, and myeloid cells) bound thrombin-stimulated platelets. Monocyte-derived macrophages kept in culture for one week also exhibited reduced binding of thrombin- stimulated platelets. IgG and fibronectin could be ruled out as ligands that mediate binding.     

Intraocular pressure changes following 20G pars‐plana vitrectomy

Purpose: To observe the excursions of short‐term intraocular pressure (IOP) after 20‐G pars‐plana vitrectomy (ppV). Material and methods: In a prospective study, 851 patients (age: mean 63 ± 15 years) underwent unilateral ppV for various vitreoretinal diseases using different endotamponades [Balanced Salt Solution (BSS) 33.1%, Air 7.2%, SF₆ 33.6%, silicon oil 5000 cst 26.1%]. Intraocular pressure was measured in all patients before and at 3, 6, 24 and 48 hr after surgery. Survival analysis was performed to determine the cumulative hazard of IOP changes depending on endotamponade and time point after ppV (Log‐Rang ‐ Mantel Cox; p < 0.0001). Results: At baseline, IOP ranged from 0 to 50 mmHg (mean IOP: 15.3 ± 5.3 mmHg). Mean IOP after surgery revealed a slight elevation (3 hr: 16.5 ± 11.0 mmHg; 6 hr 16.9 ± 9.8 mmHg; 24 hr 19.7 ± 8.0 mmHg; 48 hr 17.3 ± 6.2 mmHg; range: 0–64 mmHg). Silicon oil filling revealed highest mean values at already 3 hr after surgery (21.8 mmHg). Also, BSS filling showed a peak after 3 hr; however, mean values were lower. Equivalent high IOP values as for silicon oil tamponade were found for gas filling; however, maximal peak was reached after 24 hr but not after 3 hr post‐treatment. The cumulative hazard in all patients to reach IOP ≥ 30 mmHg after 24 hr was 23.9%; (IOP ≥ 40 mmHg = 8.2%). Herein, oil filling revealed highest risk at all time points after surgery. The risk of suffering from IOP < 5 mmHg lasting longer than 6 hr was only 1.2% after 20 G vitrectomy. Conclusion: Intraocular pressure measurements after ppV are important to prevent unintentional high IOP, especially within the early phase (3 hr post‐treatment) in eyes with silicon oil filling. Gas filling leads to prolonged IOP increase (24 hr post‐treatment). Long‐lasting hypotony (≥6 hr) is very rare after 20G vitrectomy.     

循证护理应用才精神科患者的效果评价

目的运用循证医学的思维方法，探讨在精神科护理工作中开展循证护理所达到的临床康复效果。方法将120例男性住院精神分裂症患者随机分为研究组和对照组各60例，研究组接受为期2个月的以循证理论为依据的综合性心理护理和技能训练，对照组常规给予一般支持性心理护理。采用护士用住院患者观察量表（NOSIE）、简明精神病评定量表（BPRS）、社会功能缺陷筛选量表（SDSS）、精神科症状自评量表（SCL-90）和自制的患者满意度／舒适度调查表作为评价工具，比较2组干预后的效果。结果入组时，所有量表评分2组间比较差异均无统计学意义（P〉0.05），经过2个月的治疗和循证干预后，2组间各量表评分比较，研究组优于对照组，差异均有统计学意义（P〈0.05）。结论循证护理可促进科学、有效的精神科护理实践活动，有助于促进精神分裂症患者的临床治疗和康复，为科学有效的临床护理决策提供依据和工作方法。