Visibility of the normal retinal nerve fiber layer correlated with rim width and vessel caliber

Since the distribution of the retinal nerve fiber layer (RNFL) is not regular, this study was performed to evaluate the normal regional variation in its ophthalmoscopic appearance. Wide-angle red-free photographs of the RNFL and color stereo optic disc slides of 195 normal eyes of 119 subjects were morphometrically examined. The RNFL was most visible in the temporal inferior sector, with the neuroretinal rim being correspondingly broadest (P < 0.001) and the diameter of the corresponding retinal artery the widest; these parameters were found to diminish appreciably in the temporal superior sector, the nasal superior sector, and the nasal inferior sector in this order. The visibility of the RNFL in a particular region therefore correlates positively with the rim width and retinal artery caliber in that region, the RNFL being most detectable in the temporal inferior part of the fundus. This may be important in the evaluation of eyes with optic nerve damage.     

Frequency doubling perimetry in glaucoma early diagnosis

Frequency-doubling perimetry (FDP) is a new, out-of-the-ordinary, visual field testing method. Its sensitivity and reliability was tested in 16 patients (32 eyes) with ocular hypertension and 21 patients (37 eyes) with early chronic glaucoma. Significant defects were found in almost 10% of hypertensive eyes and in 67.7% of glaucomatous eyes. FDP is an effective and sensitive technique for glaucoma functional loss assessment.     

A multivariate sensory model in glaucoma diagnosis

PURPOSE: To evaluate whether the combination of two psychophysical and two electrophysiological procedures improves diagnostic validity compared with single procedures. METHODS: In a clinical study, 73 patients with glaucoma from the University Eye Hospital in Erlangen and 122 healthy control subjects from the university staff, ranging in age from 19 to 62 years, underwent measurement of temporal contrast sensitivity using a full-field flicker test, spatiotemporal contrast sensitivity, blue-on-yellow visual evoked potential (VEP), and a black-and-white, pattern-reversal electroretinogram. Diagnostic reference criteria included applanation tonometry, optic disc morphometry, and automated perimetry. Sensitivity was determined univariately with a fixed specificity of 80% and in a multivariate approach using logistic regression analysis. The classification rate was estimated using the leaving-one-out method. The correlation with intraocular pressure, visual field defects, and optic nerve defects was determined. RESULTS: Contrast sensitivity measurements and the blue-on-yellow pattern-onset VEP showed comparable sensitivity (85%, 84%, and 85%) with 80% specificity, and a pattern-reversal electroretinogram showed lower sensitivity (64%). The first three methods contributed independent information to a diagnostic score. This score improved sensitivity to 94%, with a specificity of 89%. All procedures moderately correlated with the neuroretinal rim area of the optic disc (r=0.32-0.46). The psychophysical tests showed a higher correlation with visual field defects (r > 0.5) than the electrophysiological tests (r < 0.3). CONCLUSIONS: The multivariate approach substantially increased the diagnostic validity compared with single procedures. This was probably because the diagnostic procedures under investigation tested different aspects of visual function.     

Angle-closure glaucoma. Etiology and differential diagnosis]

The primary factors in determining beef quality grades are the amount and distribution of intramuscular fat percentage (IMFAT). Texture analysis was applied to ultrasound B-mode images from ribeye muscle of live beef cattle to predict its IMFAT. We used wavelet transform (WT) for multiresolutional texture analysis and second-order statistics using a gray-level co-occurrence matrix (GLCM) technique. Sets of WT- and GLCM-based texture features were calculated from ultrasonic images from 207 animals and linear regression methods were used for IMFAT prediction. WT-based features included energy ratios, central moments of wavelet-decomposed subimages and wavelet edge density. The regression model using WT features provided a root mean square error (RMSE) of 1.44 for prediction of IMFAT using validation images, while that of GLCM features provided an RMSE of 1.90. The prediction models using the WT features showed potential for objective quality evaluation in the live animals.     

Laser scanning laser ophthalmoscopy in diagnosis of juvenile glaucoma cases with myopia

The diagnosis of the open angle glaucoma in myopic eyes remains one of the major problems, as the changes of the optic head in myopia may be similar to glaucomatous changes. The aim of the study was to analyse biomorphometric parameters of the optic nerve head in myopic eyes with glaucoma with scanning laser ophthalmoscope from Laser Diagnostic Technologies Inc. There was 29 children examined and among them 12 children with glaucoma and myopia as a study group (I) and 17 children with myopia as a control group (II). RESULTS: TCA means values; group I: 1.994 +/- 0.158, group II:2.028 +/- 0.200 CD means values; group I; 0.315 +/- 0.072, group II: 0.247 +/- 0.057 Rim means values; group I: 1.366 +/- 0.164, group II: 1.511 +/- 0.136 Vol. A mean values; group I: +0.205 +/- 0.03, group II: +0.83 +/- 0.03 Vol. B mean values; group I: -0.159 +/- 1.608, group II: -0.117 +/- 0.08. Average values of the biomorphometric parameters of the optic nerve head were worse in group I than in group II, but there was not statistical significance between the differences. Scanning laser ophthalmoscopy may be used as very important additional examination in juvenile glaucoma cases with myopia.     

Positive donor rim culture in penetrating keratoplasty

A 3-year retrospective study on the risk factors of positive donor rim cultures in penetrating keratoplasty was performed. One thousand and ninety-seven consecutive donor rim cultures were reviewed from the period between June 1990 and October 1993 to determine the rate of culture positivity. The sex, age, diabetes status, use of respirator at time of death, cause of death, harvesting technique, storage time, and corneal storage medium utilized for the donors with positive donor rim culture were compared to those for 100 randomly selected culture negative donor controls. Logistic analysis was performed to eliminate confounding effects. Forty-six of the 1,097 (4.19%) donor rim cultures were positive. We found an association between the in situ technique for donor harvesting and culture negativity (p = 0.03). None of the other donor characteristics was associated with culture positivity. None of the 46 recipients who received the positive culture corneas developed endophthalmitis. In situ cornea harvesting promotes less contamination than enucleation and enriched gentamicin and streptomycin storage medium may further decrease donor rim culture positivity.     

The morphological diagnosis of Helicobacter pylori in the gastric mucosa in chronic gastritis]

JC virus (JCV), a human polyomavirus, is the agent of the demyelinating disease progressive multifocal leukoencephalopathy (PML). JCV exists in four main genotypes in the USA. Type 1, including subtypes Type 1A and Type 1B, makes up about 64% of strains in the USA and is thought to be of European origin. Type 2 is found in Asia, and Type 3 in Africa. A fourth type is found only in the USA. In general, these genotypes differ in 1-2.5% of their DNA sequence. Thirty MS patients and 30 paired controls from Budapest were studied. The clinical course of MS was mainly secondary progressive, and patients were stable at the time of testing. Most of the controls were relatives of the probands: a spouse, parent, or child. Overall, 25 of 60 (42%) of the urines tested positive for JCV by PCR. These included 13 of 30 MS patients, and 12 of 30 controls. Genotyping in the VPI gene showed all 25 JCV strains to be Type 1. Among the MS patients, seven were Type 1A and six were Type 1B. Among the controls, nine were Type 1A and three were Type 1B. In five pairs of MS patients and controls, both were positive for JCV by PCR. Two of these were husband/wife pairs of which one pair was matched for subtype (both Type 1A), and the other was not. Two of them were mother/daughter pairs, and both were matched for subtype (both Type 1B). These findings demonstrate that JCV Type 1 predominates among Hungarians, and suggest that parent/child pairs can be used to trace JCV transmission within the MS family.     

形态分量分析在滚动轴承故障诊断中的应用

滚动轴承局部故障振动信号中的周期性冲击是识别故障的关键特征.形态分量分析在由多种形态原子组成的过完备字典基础上提取信号中的不同形态成分,基于这种思想提出了一种基于新型过完备复合字典的形态分量分析方法.依据滚动轴承故障振动信号中分量间的形态差异性,改进字典后该方法可以更具针对性地提取出包含故障特征的冲击分量,配合包络谱分析准确提取故障特征频率,诊断滚动轴承局部故障.对比基于快速谱峭度法的轴承故障诊断方法,该方法可以避免人为选择共振带产生的不准确性和非最优问题,提高了故障诊断效果.通过轴承仿真信号和故障实验信号分析验证了该方法的有效性.     

Possibilities and limits of the morphological diagnosis of rheumatoid arthritis]

For the morphological diagnostics of rheumatoid arthritis only the judgment of the synovial membrane is of practical importance. Based on the experience gleaned on more than 2,000 synovectomy preparations the following evidence concerning the possibilities and the limits of the morphological diagnostics and the judgment of activity can be enunciated. 1. A certain histological diagnosis of the rheumatoid arthritis is possible only when rheumatoid granulomas or their equivalents are proved. 2. A probability diagnosis results from a definite combination of symptoms of proliferative and exsudative reactions of the synovial membrane. Especially the absence of proliferative signs decreases the degree of probability of the diagnostic evidence. 3. Seropositive and seronegative cases do not reveal any differences in histological respect. The possibility of the class-specific determination of rheumatoid factors by means of an immunofluorescence test and the fact the seronegative cases showed IgM and IgM rheumatoid factors, when this test was used, demands an examination of this evidence. 4. As to the synovial membranes of large joints in the same membrane so distinctive local differences of the findings may exist that thus the value of the needle biopsy is restricted. Only positive findings may be evaluated diagnostically. 5. Apart from a diagnosis the histological findings of the synovial membrane also allow a judgment of the local activity. The basis activity and the actual activity are differentiated. The basis activity is regarded as an expression of the immunological activity, the actual activity as an expression of the inflammatory activity. There are no unambiguous relations to the total clinical activity. Differences in the behaviour of the activity between seropositive and seronegative cases are not to be proved. A revision of this evidence under the aspect of the class-specific proof of the rheumatoid factor is necessary.     

Renal medullary rim sign in 2 adult quarter horses

This report describes a renal ultrasonographic abnormality (medullary rim sign), which was identified in 2 separate cases of spontaneously occurring disease associated with chronic and acute overdosage of phenylbutazone therapy. In horses, medullary rim sign has only been documented in neonatal foals experimentally administered large doses of phenylbutazone.     

Dark rim around choroidal neovascularization in indocyanine green angiography

Experimentally produced choroidal neovascularization (ChNV) surrounded by a dark rim in indocyanine green (ICG) angiography was studied histopathologically. Dark rims were seen in 28% of ChNVs which were detected with ICG angiography 2 weeks after photocoagulation. During the developing stage of ChNV, the dark rim around it was seen in the early phase of ICG angiography, but in the late phase, the dark rim became unclear because of extravascular dye leakage. During the regressive stage, the dark rim was seen in all phases of angiography. It was especially clear in the late phase. Histopathologically, at the site of the dark rim the retinal pigment epithelial cells proliferated to surround the ChNV in the subretinal space during both stages. These results show that proliferated retinal pigment epithelium surrounding ChNV blocks the fluorescence of the choroid, and causes the dark rim. The dark rim is helpful for diagnosis of ChNV.     

Structural changes in a railway wheel rim during operation

The structural changes in the near-surface layers of a railway wheel rim are studied during operation in rolling stock. The standard operating conditions of rail transport are shown to be characterized by alternating impact loading; regular braking; and, hence, periods of rapid heating of the surface layers in wheels that are replaced by intense heat removal after the end of braking of rolling stock. In this case, the heating of wheels is sufficient for the beginning of phase transformations, which result in softening, embrittlement, and strain aging of the near-surface layer metal.     

The rim sign in epidural hematoma: case report

A case of epidural hematoma of 7 days' duration showed a rim sign in the dynamic and static brain images. The significance and value of a rim sign are discussed.     

Malignant glaucoma induced by miotics postoperatively in open-angle glaucoma

A case of malignant glaucoma that developed in a patient with primary open-angle glaucoma is described. The malignant course was induced during the immediate postoperative period by the inadvertent use of miotics. The malignant course was successfully managed by osmotic agents, acetazolamide, cycloplegics, mydriatics, and topical steroids.     

Comparative evaluation of visual function computer examining methods for early diagnosis of glaucoma]

The statistical uncertainty caused by speckle noise artifacts is the reason for the great importance of the problem which is the optimum choice between the medical diagnostic systems resolution and the statistical accuracy of histological tissue identification. The way of speckle noise suppression, which is closely associated with the well-known idea of adaptive filtration and based on the physical analysis of the origin of true and false signals, is very promising. The testing results of the nonlinear real-time adaptive filter which has been designed for a TI628A echotomoscope are presented. The filter has been shown to have a rather high contrast and space resolution and reduces the speckle noise and other artifacts of the images.     

Molecular diagnosis of mutations responsible for recurrent and severe forms of primary congenital glaucoma

BACKGROUND: A markedly increased incidence of malignancy in transplant recipients is well recognized. However, the incidence and pattern of post-transplantation malignancies shows some discrepancy among different reports. The renal transplant recipients monitored at Taichung Veterans' General Hospital comprise the largest group in Taiwan. An analysis of the characteristics of post-transplant malignancies emphasizes the differences from malignancies that occur in the Taiwanese general population and those reported in Western countries. METHODS: The incidence and characteristics of de novo malignancy in 390 renal transplant recipients who underwent renal transplantation between May 1983 and June 1996 were analyzed. A total of 232 men and 158 women (mean age at transplantation: 38.5 +/- 10.7 years) were included. The relative risk for developing malignancies was calculated based on the sex- and age-matched cancer incidence of reference for the Taiwanese population; data from the Cancer Registry Annual Report in Taiwan (1989) was obtained for comparison. RESULTS: A total of 25 cancers were diagnosed in 24 renal transplant recipients, for an incidence of 6.2%. The relative risk of renal malignancy was 13.8-fold higher among transplant recipients than in the general population. The impact of gender and age on the development of post-transplantation malignancy was not significant. The most common types of cancer were transitional cell carcinoma (TCC) of the urinary tract (8/25), and hepatoma (8/25), followed by two cases of Kaposi's sarcoma. Aside from immunosuppressive agents, the high incidence of hepatoma and TCC may be attributed to the high incidence of hepatitis infection and the possible carcinogenic effect of abnormal milieu induced by uremia per se. Survival was largely dependent on the extent of disease at presentation, and post-transplantation cancer did not show more aggressive behavior if detected early. CONCLUSIONS: The high cumulative incidence of malignancies makes it imperative to define an effective safe immunosuppressive regimen to achieve a lower risk of malignancies. In the future, the prime approach to treatment of post-transplantation malignancies should begin with early detection and ensuing aggressive treatment to improve the outcome.     

Functional topography of the on and off channels of retinal cone system in diagnosis of initial glaucoma

The analysis covers 136 cases of laparoscopic cholecystectomy. Intraoperative cholangiography is performed in seven patients. Choledocholithiasis, missed during the operation, is diagnosed in one case only two months later. Preoperative ERCP is done in three patients, and postoperatively--in two. The follow-up study of the rest of patients, not subjected to intraoperative or endoscopic cholangiography, shows that up to one year after the operation there is not a single case of missed choledocholithiasis. The indications for intraoperative cholangiography are established on the ground of criteria worked out in the clinic. The obtained data confirm the hypothesis for selective application of the examination without augmenting the risk of missing pathological changes in the biliary ducts.     

Peripapillary changes in glaucoma

A correlation between the expression or absence of human glyoxalase I and chromosome 6 (as well its markers ME1, IPO-B, and PGM3) was observed in man-mouse somatic cell hybrids. This segregation pattern indicates that the GLO gene is situated on chromosome 6.