Functional magnetic resonance imaging evidence for binocular interactions in human visual cortex

Using functional magnetic resonance imaging (fMRI), we explored the binocular interactions occurring when subjects viewed dichoptically presented checkerboard stimuli. A flickering radial checkerboard was presented to each eye of the subject, while T2*-weighted images were acquired over the visual cortex with gradient-echo, echoplanar sequences. We compared responses in striate and extrastriate visual cortex under four conditions: both eyes were stimulated at the same time (binocular condition), each eye was stimulated in alternation (monocular condition) or first the one eye then the other eye was stimulated (left eye first - right eye trailing, or vice versa). The results indicate that only the striate area, in and near the calcarine fissure, shows significant differences for these stimulation conditions. These differences are not evident in more remote extrastriate or associational visual areas, although the BOLD response in the stimulation-rest comparison was robust. These results suggest that the effect could be related to inhibitory interactions across ocular dominance columns in striate visual cortex.     

Current status of intranasal glucocorticosteroids in the management of allergic rhinitis

Glucocorticosteroids are the most effective drugs for controlling inflammation of allergic rhinitis (AR). Because of their strong pharmacological action, which can be a so-called 'double-edged sword', glucocorticosteroids are usually taken intranasally so as to reduce their potential for eliciting adverse effects. Accumulating evidence suggests that intranasal glucocorticosteroids control not only nasal symptoms but also ocular symptoms. In contrast to sedating H₁-receptor antagonists, intranasal glucocorticosteroids can improve impaired performance such as daytime sleepiness associated with AR. In Japanese cedar pollinosis, treatment begun immediately after initiation of pollen release or onset of initial symptoms, known as prophylactic (initial) treatment, is recommended. The current version of the practical guideline for management of allergic rhinitis in Japan recommends the use of chemical mediator release inhibitors, second-generation H₁-receptor antagonists, or leukotriene receptor antagonists for prophylactic treatment. However, recent evidence suggests that intranasal glucocorticosteroids might also be useful as first-line drugs for prophylactic treatment. The molecular mechanism of anti-inflammatory action of glucocorticosteroids supports this contention. Moreover, a meta-analysis of studies of intranasal glucocorticosteroids given as monotherapy has revealed that these agents are superior to oral H₁-receptor antagonists and leukotriene antagonists for controlling major symptoms of AR. These findings suggest that glucocorticosteroids, especially intranasal glucocorticosteroids, might be positioned as first-line drugs for the treatment of both perennial and seasonal AR.     

Ocular pharmacokinetic models of clonidine-3H hydrochloride

A single topical instillation of clonidine-³H HCl solution (0.2%) was administered to the rabbit eye (30 μl) in order to study the drug's ocular pharmacokinetics. Seven different tissues and plasma were excised and assayed for drug over 180min. By 45–60 min pseudoequilibrium is reached for the cornea, iris/ciliary body, and aqueous humor. Thereafter, drug levels in these tissues decline in parallel. The data are fit separately to a physiological model and a classical diffusion model for which seven ocular tissue compartments and a plasma reservoir are constructed for each model. Clearance terms and distribution equilibrium coefficients are determined from the tissue level data and used as parameters in fitting the mass balance differential equations representing the physiological model. The model parameters can also be fit to a 0.4% single dose. In a separate experiment, a topical infusion technique was designed to provide a constant rate input to the cornea until an apparent steady state was reached in aqueous humor at 55 min. Aqueous humor levels were assayed for clonidine over the infusion and postinfusion periods. The physiological model parameters are fit to the topical infusion data and show good agreement between the predicted and experimental data. The classical model is too complex to fit the data to integrated exponential equations primarily because the method of residuals is inadequate in determining a sufficient set of initial estimates. This is overcome by dividing the eight-compartment model into seven fragmental models, each representing one to five compartments. A stepwise procedure is developed in which initial estimates are obtained for each separate fragmental model and refined. The refined parameter values can then be used as initial estimates for the complex model. Differential equations for the complex model are fit simultaneously to tissue levels representing each compartment. By observation, the classical model fit the data more closely than the physiological model. Statistical moment theory is also applied to the topical infusion data to determine ocular pharmacokinetic parameters for clonidine. The calculated values are: corneal absorption rate constantk _a , 0.00139 min^?1; aqueous humor elimination rate constantk ₁₀ , 0.0658min^?1; mean residence timeMRT _d , 35.6 min; apparent steadystate volume of distributionV _ss, 0.530 ml; and ocular clearanceQ _e , 14.9 =μl/min. The fraction absorbed from the single instillation is estimated as 0.0163.     

Hyperosmolarity response of ocular standing potential as a clinical test for retinal pigment epithelium activity normative data

The standing potential of the eye is decreased by intravenous administration of hypertonic solutions. This hyperosmolarity-induced response has been recorded in normal subjects by the use of electro-oculography (EOG) in the dark. An intravenous administration of Fructmanit^® (1.4 × 10³ mOsmol) (150 500ml, 2.37 9.70ml/kg, 0.08 0.36 ml/kg/min) was used to evoke the hyperosmolarity response. The amplitude of the response was expressed in percentage, V₀ – V_min/V₀ × 100, where V₀ is the base value of the EOG before administration of the hypertonic solution and V_min is a minimum EOG amplitude after administration. The distribution of the amplitude of the hyperosmolarity response was approximated by the normal distribution in normal subjects. The minimum, the maximum, the mean and the standard deviation of the amplitude of the hyperosmolarity response were respectively 34.2%, 52.3%, 42.6% and 4.6% in normal subjects. The normal range of the hyperosmolarity response would be 33.4 51.8% (M ± 2SD). The hyperosmolarity response, which originates mainly in the retinal pigment epithelium, is a useful new quantitative and specific test of the activity of the retinal pigment epithelium in clinical practice.     

前部增生性玻璃体视网膜病变引起慢性低眼压房水生成率的测定

目的：探讨前部增生性玻璃体视网膜病变（anterior prolieferative vitreoretinopathy,aPVR)低眼压状态下房水生成率变化,从房水动力学的角度揭示aPVR引起慢性低眼压的发病机制。方法：利用培养的同种兔皮肤成纤维细胞制作aPVR引起慢性低眼的动物模型。于术前及术后不同时间点分别观测眼压、术后14d,28d,56d分别以高效液相色谱仪测量房水荧光素清除率,进一步计算房水生成率。结果：术后2周、4周、8周实验组平均眼压、房水生成率明显低于对照组（P＜0．05或P＜0．01）。结论：在aPVR病理状态下,低眼压的形成与房水生成率下降有关。     

Genetic and Developmental Influences on Infant Mouse Ultrasonic Calling. III. Patterns of Inheritance in the Calls of Mice 3–9 Days of Age

Infant mice produce ultrasonic calls that may elicit retrieval by adult mice. Age-related differences and genetic effects, such as additivity and directional dominance, have been found for most call characteristics at 3 days of age. Significant maternal effects have been reported for calling rate. However, little is known about how the influence of these genetic effects changes with age. This study explored developmental-genetic patterns of inheritance of seven ultrasonic call characteristics at ages 3–9 days, from groups of mice derived from a complete 4 × 4 diallel cross. The results indicate that additive variance contributes significantly to all characteristics for all ages. Maternal effects have a small effect on call characteristics. Dominance effects decrease with age for rate, range, and length of calls, suggesting less selective pressure toward higher rates, greater range, and longer calls as pups become more competent thermoregulators.     

川芎嗪对兔眼高压下视网膜神经节细胞和双极细胞损伤的保护作用

目的　观察川芎嗪对慢性眼高压下视网膜神经细胞损伤的保护作用 .方法　用 2 0 g· L- 1 甲基纤维素前房注射法建立兔慢性眼高压模型 .4组分别给予生理盐水、川芎嗪注射液 10 mg· kg- 1 ,2 .5 g· L- 1 噻吗心安眼液和联合应用川芎嗪与噻吗心安 ,连续用药 4wk.于 2 8d取眼球作光镜、电镜检查和光镜下细胞计数 .结果　生理盐水组模型眼节细胞数为 (7.83± 1.34 )个 /10格 ,双极细胞数为 (10 .6 6± 1.6 3)个 /格 ;川芎嗪组模型眼节细胞数为 (9.5 0± 3.87)个 /10格 ,双极细胞数为 (12 .5 0± 2 .73)个 /格 ;生理盐水组模型眼和川芎嗪组模型眼节细胞 (P<0 .0 5 )与双极细胞 (P<0 .0 5 )比较 ,有显著性差异 .生理盐水组模型眼节细胞变性、坏死 ,锥、杆细胞外节紊乱 ,色素上皮不完整 ,川芎嗪组变化比生理盐水组轻 ,联合用药组变化最小 .结论　川芎嗪对慢性眼高压下视网膜神经节细胞和双极细胞具有保护作用 .     

新鲜羊膜移植治疗眼表疾病的临床评价

目的 评价新鲜人羊膜在眼表重建术手术中的临床价值。方法 用新鲜羊膜移植,治疗陈旧性睑球粘连、结膜囊缺失,复发性翼状胬肉、蚕蚀性角膜溃疡、热烧伤后角膜和结膜溶解等眼表疾病的连续病例１９例（２１只眼）。结果 １９例患者的羊膜移植手术均为一次成功。平均随访１２．５个月,羊膜移植片未见免疫排斥反应或溶解吸收。手术后,患者的睑球粘连松解,结膜囊形成,蚕蚀性角膜溃疡和复发性翼状胬肉在随访期间未见复发,角膜和结     

Crossed aphasia. An update

The aim of this article is to present an update of a rare but interesting problem: crossed aphasia. This term indicates the presence of aphasia after unilateral cerebral lesion of the hemisphere ipsilateral to the patient's dominant hand. We report two cases, review the most relevant literature, and analyze clinical, neuroanatomical, and neurophysiological aspects, taking in consideration the various interpretations proposed to explain this unusual language disorder.     

A study of comparison between the nationwide epidemiological survey in 1991 and previous surveys on behçet’s disease in Japan

The 4th nationwide epidemiological survey on Behçet disease (BD), which included all patients with BD at 1,200 hospitals selected at random from 10,081 hospitals in Japan, was carried out by the BD Research Committee of the Ministry of Health and Welfare in 1991 to examine the epidemiological features of BD in Japan by comparing with previous surveys. 3,938 patients from these hospitals were examined by the Japanese diagnostic criteria of BD (JCBD) revised in 1987 and the International criteria for classification of BD (ICBD). Among these 3,938 patients, 622 patients were only suspected of having BD or clinical signs of the disease were unknown, and most of these patients were incompatible with the ICBD. So these patients were excluded from the study of epidemiological features. The average patients age has risen 7–8 years over the last 20 years and the average age of onset in both sexes increased by about 3 years from 1972 to 1991. While a decrease in the sex ratio was seen in the complete-type and the incomplete-type BD without ocular symptoms, a sustained high sex ratio was shown in incomplete-type BD with ocular symptoms. The positive rate of HLA-B51 antigen was 54.9% (men: 56.9%, women: 52.2%) significantly higher than die 15–16% in healthy subjects but it might have been gradually decreasing. Also the clinical course of BD has become too mild for prognosis. According to diese epidemiological features of BD, the clinical manifestation of BD in Japan might have become the Western type of BD.