2007年 · 第120卷第04期

Glaucoma research in China has been booming in recent years. The research involves from gene mapping and functional assessment to surgical treatment using phaco alone, trabeculectomy or phacotrabeculectomy in angle closure glaucoma.1,2 The Panel of Glaucoma of the Chinese Ophthalmological Society has established the diagnosis and classification system for glaucoma with reference to the Preferred Practice Pattern (PPP) introduced by the American Academy of Ophthalmology in 2005。

Abstract：Background The recent studies have shown that visual performance might be affected by the ocular aberration after the corneal refractive surgery, and try to minimize it. This study was to investigate the effects of photorefractive keratectomy (PRK) and laser in situ keratomileusis (LASIK) on the higher order of wavefront aberration and analysis of their characteristics.Method This prospective study involved 32 eyes with similar refractive powers (-5.0 D to -6.0 D preoperatively). LASIK and PRK were performed with the same parameters of 6 mm diameter optical zone and 7 mm diameter transition zone ablation. Wavefront aberrations were tested using a ray tracing technique preoperatively and 3 months postoperatively.Three measurements were obtained for each condition; the root mean squared wavefront error (RMS), values for overall wavefront aberrations and each order of the Zernike aberrations were analyzed using the Matlab software. The 2-tailed t test was used for statistical analysis.Results Overall higher order aberrations were increased from (0.55±0.26) μm preoperatively to (0.93±0.37) μm for PRK and (0.79±0.38) μm for LASIK postoperatively. This was a 1.69 fold increase in the PRK group (t=3.95, P＜0.001)and a 1.43 fold increase in the LASIK group (t=2.60, P＜0.05). At 3 months, the mean RMS value for higher-order (3rd to 6th) were significantly increased compared with the corresponding preoperative values (P＜0.05). The fourth order aberrations, spherical like aberration, were dominant by a 2.64 fold in PRK and a 2.31 fold in LASIK. Different influences of the PRK group and LASIK group were shown in the various zernike components. The statistically significant differences were seen in C40, C4+4, C5+1, C5+3, C5+5 and C6+2 of the PRK group and C3-3, C40, C5-5, C5+5, C6-2 of the LASIK group, which represents a 7.42, 3.58, 9.21, 2.72 and 5.3 fold increases in PRK group, and 6.40, 10.80, 11.06, 3.47 and 6.09 fold increases in LASIK group, respectively. C3-3 in LASIK was higher and C5+1 and C5+3 were lower than those in the PRK group. C40 (spherical aberration) values were similar between PRK and LASIK, however, C3-1 and C31 (coma) in LASIK were higher than those in PRK, but these differences are of no statistical significance.Conclusions PRK and LASIK may increase ocular higher-order aberrations, but they both have their own features.The difference between the two types of surgery may be correlated with the change of the corneal shape, the conversion of biodynamics, the healing of the corneal cut, and re-structured corneal epithelium and/or the stroma。

Abstract：Background Corneal neovascular leakage can lead to edema and secondary scarring. Previous studies have shown that pericytes play a key role in maturation of angiogenesis. The present studies investigate the relationship between vascular permeability and pericyte coverage of endothelial cells in rat corneal neovascular induced by alkali burns.Methods Corneal neovascular vessels induced by alkali burns was performed in Sprague-Dawley rats. Corneas were excised on 1, 2, 3, 5, 7 and 10 days after cauterization. The vascular permeability rate was measured by the Evans blue method. The microvessel pericyte coverage index (MPI) was applied to quantify the pericyte coverage through double immunofluorescent staining of frozen sections of corneas with CD31 as the endothelial and α-smooth muscle actin(α-SMA) as the pericyte markers. The correlation between permeability rate and MPI was analyzed. Pericyte coverage was confirmed ultrastructually using transmission electron microscopy.Results The vascular permeability rate was (1.14±0.17), (0.24±0.08), (0.29±0.16), (0.14±0.10), (0.09±0.06) and (0.05±0.04) μg·ml-1·mm-2 respectively on 1, 2, 3, 5, 7 and 10 days after cauterization. The MPI was 0, 16.07%,11.95%, 43.84%, 73.97% and 86.21% respectively at the above mentioned time points. The correlation coefficient between MPI and the permeability rate was -0.943 (P=0.005).Conclusions Pericyte recruitment was significantly correlated with the permeability of corneal neovascularization induced by alkali burns in rats. Therapeutic strategies aiming at anti-leakage should be most effective if they promote pericytes proliferation in the course of corneal neovascularization。

Abstract：Background "Vision 2020" was initiated in 1999 and many relevant activities are ongoing, but little information is available on what it has achieved and what constraints it faces. It is not yet clear if funding is the most important constraint. Nepal is one of the underdeveloped countries, but an advanced country in preventing avoidable blindness.The aim of this study was to compare the situation in China and in Nepal in prevention of avoidable blindness.Methods Data from literature review and a field visit were combined. All statistical analyses were carried out with SPSS Version 11.5. The chi-square test was used for comparisons involving categorical variables.Results The blindness rate is higher in Nepal than that in China (P＜0.05). The average number of cataract operations performed by one ophthalmologist is much lower in China than in Nepal. The cataract surgical rate (CSR) is much lower in China than in Nepal (P＜0.001). High cost of the surgery and inadequate qualifications of human resources were found in China. Cataract surgical outcome in China compared well with international standards.Conclusions Progress towards the "Vision 2020" target in China is much slower than that in Nepal. Further attention to address this issue is urgently needed。

Abstract：Background Phacoemulsification yields successful outcomes in eyes with standard cataract. Though techniques have been improved, it is still challenging to perform phacoemulsification in cases of hard cataracts for difficulty in nuclear management and much more complications. This study aimed at describing and evaluating the efficacy and safety of a peripheral radial chop technique to remove hard cataracts.Methods In this prospective study conducted between January 2003 and January 2004, 107 consecutive eyes with hard cataract underwent modified phacoemulsification surgery with peripheral radial chop technique by the Bausch & Lomb Millennium phacoemulsifier with preset parameters of power less than 30%; vaccum, 150 mmHg; and bottle height,85 cm when a DP8145 phaco tip was used, and vaccum, 380 mmHg; bottle height, 95 cm when a DP8245 phaco tip was used.Results The mean ultrasonic power was 14.7% (range 9% to 19%), ultrasonic time was 1.98 minutes (range 1.55 to 3.18 minutes). At 1, 7 and 30 days postoperatively, the eyes with uncorrected visual acuity 0.5 or better accounted for 76.42%, 87.16% and 90.67% respectively. At 1 month, the endothelial cell loss rate was 9.74% (range 8% to 17%). There were 6 cases of posterior capsule rupture in an early period of study. No serious intraoperative or postoperative complications were noted.Conclusions The peripheral radial chop technique was effective without serious complications in hands of an experienced surgeon。

Abstract：Background Accurate prediction for prognosis is important for hospitalized patients with chronic obstructive pulmonary disease (COPD) requiring invasive mechanic ventilation (IMV) and for their family members to make end-of-life decisions. The response to therapy in such a patient population has rarely been investigated. The aim of the study was to evaluate the risk factors in these patients and investigate their response to IMV and the relationship between their responses and prognosis.Methods A cohort of 138 patients with COPD requiring IMV≥12 hours for acute respiratory failure of diverse etiological factors during a 4-year period were retrospectively studied using prospectively gathered data. All variables potentially related to hospital mortality were evaluated by univariate and multiple stepwise logistic regression analysis.Results The mean age of all patients investigated was (65.7±11.6) years and the hospital mortality was 39.9%(31.1% with COPD exacerbation). Correction of acidosis (pH≥7.30) was seen in 58 patients (69.9%) in survivors but only 12 patients (21.8%) in nonsurvivors (P＜0.05) after ventilation. Using multivariate logistic analysis, the variables independently associated with hospital mortality were a higher acute physiology score before intubation, lower pH value measured 24 hours after the onset of ventilation and development of multiorgan dysfunction syndrome (MODS).Conclusions In COPD patients requiring IMV, the postintubation pH value can not only reflect patients' response to treatment, but also serve as an independent determinant of hospital mortality apart from other risk factors such as a higher preintubation APACHE II score and development of MODS. A close correlation between the response to IMV and prognosis was proved in these patients。

Abstract：Background Hepatitis C virus (HCV) core antigen assays have been produced to exclude infectious donations collected during the preseroconversion window phase (PWP). For the same purpose, we evaluated the specificity and sensitivity of a novel hepatitis C virus NS3 antigen detection immunoassay and the application of this assay in clinical diagnosis.Methods Samples from 77 healthy subjects, 173 anti-HCV positive patients and 3708 hepatitis patients other than HCV positive were tested with the HCV NS3 antigen assay. Some HCV NS3 antigen positive samples were further validated with HCV-RNA, neutralization and immunodot assays. Twenty-five sequential samples from 11 HCV NS3 antigen positive patients were subjected to kinetic study.Results Only 48 (1.3%) of 3708 anti-HCV negative samples were positive for HCV NS3 antigen. Among them, 44 of 3030 samples from patients only infected with HBV were HCV NS3 antigen positive, 4 of the 445 samples from patients infected with other type hepatitis were HCV NS3 antigen positive. In addition, 42 (24.3%) of 173 anti-HCV positive samples were HCV NS3 antigen positive and all 77 samples from healthy subjects were negative to HCV NS3 antigen assay. Of the 15 HCV NS3 antigen positive samples, 9 (60%) were HCV-RNA positive. The neutralization and positive percentage of immunodot assay for 23 HCV NS3 antigen positive sera were 87.0% (20/23) and 69.6% (16/23)respectively. Of the 25 sequential samples from 11 HCV NS3 antigen positive patients, there was a negative correlation between the OD values and the duration of test (r=-0.989, P＜0.05), and there were correlations among their HCV NS3 antigen, HCV-RNA and anti-HCV titres. The anti-HCV antibodies of two sera were detected while their OD values of HCV NS3 antigen decreased gradually.Conclusions The HCV NS3 antigen detection assay showed perfect specificity and high sensitivity. Thus, it would be useful and economical as a routine test in laboratories for early diagnosis of HCV infection and prevention。

Abstract：Background Adipose-derived stem cells (ADSCs) are capable of differentiating into cardiomyogenic and endothelial cells in vitro. We tested the hypothesis that transplantation of ADSCs into myocardial scar may regenerate infracted myocardium and restore cardiac function.Methods ADSCs were isolated from the fatty tissue of New Zealand white rabbits and cultured in Iscove's modified dulbecco's medium. Three weeks after ligation of left anterior descending coronary artery of rabbits, either a graft of untreated ADSCs (UASCs, n=14), 5-azacytidine-pretreated ADSCs (AASCs, n=13), or phosphate buffer saline (n=13)were injected into the infarct region. Transmural scar size, cardiac function, and immunohistochemistry were performed 5 weeks after cell transplantation.Results ADSCs in culture demonstrated a fibroblast-like appearance and expressed CD29, CD44 and CD105. Five weeks after cell transplantation, transmural scar size in AASC-implanted hearts was smaller than that of the other hearts.Many ADSCs were differentiated into cardiomyocytes. The AASCs in the prescar appeared more myotube-like. AASCs in the middle of the scar and UASCs, in contrast, were poorly differentiated. Some ADSCs were differentiated into endothelial cells and participate in vessel-like structures formation. All the ADSC-implanted hearts had a greater capillary density in the infarct region than did the control hearts. Statistical analyses revealed significant improvement in left ventricular ejection fraction, myocardial performance index, end-diastolic pressure, and peak +dP/dt, in two groups of ADSC-implanted hearts relative to the control hearts. AASC-implanted hearts had higher peak -dP/dt values than did control, higher ejection fraction and peak +dP/dtvalues than did UASC-implanted hearts.Conclusions ADSCs transplanted into the myocardial scar tissue formed cardiac islands and vessel-like structures,induced angiogenesis and improved cardiac function. 5-Azacytidine pretreatment before implantation is desirable for augmenting myogenesis. Transplantation of 5-azacytidine-treated ADSCs into the myocardial scar was more efficient than that of untreated ADSCs in preservation of cardiac function。

Abstract：Background In the process of hepatic fibrosis, the accumulation of collagen fibers is strongly related to the hepatic function. The aim of this study was to investigate the three-dimensional architecture of the collagen network in the liver of rats with hepatic fibrosis.Methods Healthy adult male Wistar rats (n=32) were randomly divided into a control group (n=16) and a hepatic fibrosis group (n=16). In the control group, the rats were treated with peanut oil while the rats in hepatic fibrosis group were treated for 10 weeks with 60% CCl4 diluted in peanut oil. The quantity of collagen fibers was detected by Western blotting; distribution of the collagen was detected by sirius red staining and polarized microscope; the three-dimensional architecture of collagen in the liver was observed under the scanning electron microscope after fixed tissues were treated with cell-maceration using NaOH. Statistical analysis was performed using the u test.Results The quantity of collagen fibers increased significantly in the hepatic fibrosis group. With the aggravation of hepatic fibrosis, collagen fibers gradually accumulated. They interlaced the reticulation compartment and formed a round or ellipse liver tissue conglomeration like a grape framework that was disparate and wrapped up the normal liver Iobule.The deposition of collagen fibers was obvious in adjacent hepatic parenchyma, especially around the portal tracts.Conclusion Our experiment showed the collagen proliferation and displays clearly the three-dimensional architecture of collagen fibers in rat liver with hepatic fibrosis by scanning electron microscope. It can provide a morphological foundation for the mechanisms of changed haemodynamics and portal hypertension in hepatic fibrosis。

Abstract：Background We analysed and compared the aquaporin 8 (AQP8) expression in ascending and descending colon mucosa between patients with diarrhoea-predominant irritable bowel syndrome (D-IBS) and healthy volunteers, in order to study the relationship between the clinical feature of IBS, the expression of AQP8 and the pathological mechanism of D- IBS.Methods Specimens were taken from the proximal ascending colon or distal descending colon of D-IBS patients (n=26)and healthy volunteers (n=30), and AQP8 mRNA expression of each specimen was determined by fluorescent quantitative reverse transcription polymerase chain reaction (FQ-RT-PCR). In patients with D-IBS, the relationship was analysed between AQP8 expression in both ascending and descending colons and clinical features including gender,age of onset, duration of illness, frequency of defecation, and stool characteristics.Results Although AQP8 was present in the epithelium of the ascending and descending colons in healthy persons and D-IBS patients, the AQP8 level of the D-IBS patients was significantly lower than that of the healthy persons (P＜0.01 in the ascending colon, P＜0.05 in the descending colon). AQP8 expression was not correlated with the age of patients with D-IBS (P＞0.05 both in the ascending and descending colons) or the age at the onset (P＞0.05 both in the ascending and descending colons), but closely with the duration of illness (P＜0.05 in the ascending colon, P＜0.01 in the descending colon), frequency of defecation (P＜0.01 in the ascending colon, P＜0.05 in the descending colon) and stool characteristics (P＜0.01 in the ascending colon, P＞0.05 in the descending colon).Conclusions The decreased AQP8 expression in D-IBS patients indicates that dysfunction of colonic absorption may cause reduced water absorption, loose stool and diarrhoea. The expression of AQP8 may be related to D-IBS。

Abstract：Background We managed to assess and confirm the risk factors for mortality after coronary artery bypass grafting (CABG) operations so as to map out the proper guidance of surgical strategy especially in patients with low left ventricular ejection fraction (LVEF) in domestic polyclinic like ours.Methods Five hundred and forty-eight consecutive patients underwent CABG from December 1999 through August 2005 were analyzed retrospectively. Eighty-nine cases had an LVEF of 40% or less. All together twenty-two candidate factors were evaluated for their association with perioperative death using univariate and multivariate stepwise Logistic analysis.Results When data from all the patients who had undergone CABG were taken into account, LVEF, left ventricular end diastolic diameter (LVEDD), mitral regurgitation, aneurysm of the heart wall, mitral repair/replacement, resection of aneurysm, concomitant aortic valve replacement, and perioperative intra-aortic balloon counter-pulsation (IABP), left ventricular assist device (LVAD) and cardiopulmonary bypass (CPB) all showed an association with perioperative death in univariate analysis, while an LVEF of ＞40%, on the other hand, appeared to be a protective factor. In multivariate analysis, moderate to severe mitral regurgitation, aneurysm of the heart wall, repair of septal perforation and aortic regurgitation were proved to be risk factors. When the analysis was restricted to patients with an LVEF of 40% or less,such variables as age, LVEDD, mitral regurgitation, mitral repair/replacement, IABP, and CPB were qualified as risk factors in a univariate analysis. Age, moderate mitral regurgitation, aneurysm of the heart wall, CPB, left main coronary artery disease and female were associated with perioperative death in a multivariate logistic regression analysis.Conclusions Concerning the prognosis, patients who undergo CABG would have different risk factors when data from all the enrolled patients or data from patients with LVEF≤40% is compared. This is because low LVEF is itself an important risk factor. Regarding the low LVEF patients, the aggressive treatments including correction of mitral regurgitation and resection of aneurysm of the heart wall concomitant with CABG should be taken into account while planning the operative strategy to ensure the perioperative safety and prognosis。

Glaucomatous optic neuropathy is characterized by progressive loss of retinal ganglion cells associated with visual functional deficits. As the ganglion cells die in glaucoma, there is a progressive thinning of the nerve fibre layer (NFL).1 The underlying pathophysiological mechanisms, however, remain unclear。

Fiberoptic bronchoscope (FOB) is an important instrument for respiratory, disorder examination and difficult airway management.1 The fiberoptic intubation can avoid the mechanical stimulus to oropharyngolaryngeal structures thereby it is likely to attenuate hemodynamic responses during orotracheal intubation。

Although P300 abnormalities of event-related potentials (ERPs) are consistently reported among schizophrenic patients as being the most compelling indices of their brain dysfunction,1 whether they are trait markers or state markers of schizophrenia remains in controversy.2,3 To shed a light on this point, we made a longitudinal study of P300 among first episode schizophrenic patients, from no medication until the patients had been medicated for 12 weeks。

The skull base communicating tumor is characterized by simultaneous invasion of the intracranial and extracranial structures. The tumor may originate from the intracranial structures and invade extracranially, or vice versa. The total resection of the tumor is difficult, and a lot of complications may occur after the operation。

Together with an increasingly aging world population there is also an increasing prevalence of atherosclerosis. Renal artery stenosis (RAS) is one of the systemic manifestations of atherosclerosis. Its incidence is about 15%-35%.1 RAS accounts for 5%-27% of all patients with end-stage renal disease (ESRD).2 Patients with renal dysfunction resulting from RAS are at risk of death from cardiovascular disease and ESRD.3

Cognitive neuropsychology has made great contributions to our understanding of the neural basis of language since Broca's seminal work;1 the primary neural circuitries for language processing have been documented.

Vascular leiomyomas are extremely rare in the nasal cavity, accounting for less than 1% of all vascular leiomyomas.1 The association of Epstein-Barr virus (EBV)with smooth muscle tumors in immunocompromised patients is well established。