Transneuronal WGA-HRP: can it demonstrate development of ocular dominance patches and effects of monocular deprivation?

We have attempted to use intraocular injections of wheat germ agglutinin-horseradish peroxidase (WGA-HRP) to label ocular dominance patches in developing layer 4 of cat visual cortex. The cortices of animals killed at 49 days or later showed normal ocular dominance patches similar to those seen in [3H]proline material. Animals killed at 42 days showed some patches, but also showed unsegregated regions. Animals killed younger were difficult to stain and did not have patches. We also examined the ability of the WGA-HRP technique to demonstrate the effects of monocular deprivation (MD). MD for the first 3 months of life produced expansion of the afferents from the nondeprived eye and retraction of the patches from the deprived eye. One week of MD at about 5 weeks of age produced an expansion of the patches innervated by the nondeprived eye, but did not obviously affect the patches innervated by the deprived eye. We conclude that WGA-HRP is useful for examining the effects of long-term MD on ocular dominance patches but not for following the development of segregation. Its advantages over the [3H]proline technique are that it does not require a delay of many weeks before the sections can be examined and is much less expensive.     

A subconjunctival degradable implant for cyclosporine delivery in corneal transplant therapy

The effect of local cyclosporine therapy upon corneal transplant survival was investigated. A high risk rabbit model with vascularized corneas was used to assess the efficacy of subconjunctivally implanted degradable devices for cyclosporine therapy. Animals were divided into four groups, receiving either no therapy, a placebo PLGA device, or drug containing devices implanted either at the time of transplantation or two weeks previous. The mean survival times of animals in the control and placebo groups were statistically equivalent (21 +/- 4 days vs 18 +/- 4 days). Devices containing CsA improved the survival time of grafts. Predosing the animals with CsA improved the survival time to 28 +/- 7 days, and CsA devices implanted at the time of transplantation increased the survival time to 35 +/- 7 days. The improvement in survival times was consistent with the in vitro drug release profiles. No systemic CsA was detected, suggesting that the effect may have been local. Histological assessment indicated that devices were well tolerated.     

The anatomic basis and clinical applications of flaps based on the posterior tibial vessels

The vascular anatomy of the posterior tibial vessels has been studied in 20 legs of 10 cadavers. The number, size and distribution of the direct cutaneous and direct muscle branches of the posterior tibial vessels were recorded. For analysis, the leg was divided into four equal segments, Zone I being the most distal and Zone IV the most proximal. The direct cutaneous branches were found to cluster mainly around Zone II. The direct muscle branches to the soleus and flexor digitorum longus muscles arose chiefly in Zones II and III. Based on this knowledge, we performed fasciocutaneous, island soleus muscle, musculo-fasciocutaneous and flexor digitorum longus muscle flaps based on the posterior tibial vessels in 12 patients. Four were free fasciocutaneous flaps and eight were pedicled flaps. All flaps survived and there were no major complications. Delayed wound healing was encountered in three patients.     

An isometric predictor for maximum acceptable weight of lift for Chinese men

The aim of this study was to examine the practicality of the modified isometric strength tests to predict the maximum acceptable weight of lift (MAWL) of Chinese men. The modified strength tests allow the participant to pull on the load cell in front of the body and to apply force in a functional free posture. Both the modified and the standard strength data of each participant were used as predictors for the MAWLs. The prediction models were constructed and evaluated under task conditions of two lifting ranges, two box sizes, and three lifting frequencies. To realize the effect of modifications, testing posture was recorded and the joint angles were calculated. A stepwise multiple regression analysis indicated that modified composite strength (MCS), chest circumference, and acromial height accounted for 86% to 91% of the variance. Because the strength of the upper extremity body was also recruited in the test, the weak upper extremity strength of the Chinese participants would therefore be better reflected. Evidence for the existence of a close match between MAWL and MCS values, as well as the task conditions for its existence, suggest that a simple isometric strength measure is a good predictor for the MAWL.     

Traumatic tricuspid regurgitation complicating endocarditis and right-to-left intracardiac shunt. A case report of successful operation

OBJECTIVE: To assess the prevalence of cystinuria and cystine stone disease among families of patients with cystine stones, and to determine their distribution by age, sex and associated morbidity. SUBJECTS AND METHODS: The study comprised 180 relatives (87 males and 93 females, mean age 43 years) descended from two brothers over four generations who live in two areas in northern Jordan. Data were collected using a questionnaire and home visits, by urinary cystine testing and radiology to detect stone, and assessing hypertension and renal impairment. RESULTS: Of the 180 subjects, 104 (58%) had a positive reaction for cystine in urine; 33 (32%) of these were younger than 15 years. Twenty members (11%) of the families had evidence of renal cystine stone disease. Hypertension and renal impairment were detected in a significant proportion of individuals with cystine stone disease. CONCLUSION: Cystinuria is a major risk factor for cystine stone formation. Family screening is valuable in detecting the cystinuric population and in assessing individuals with stones. Early recognition, treatment and counselling result in better management and prevention. The establishment of a cystine study group in our region is essential.     

Vascular pathology of malignant cervical lymphadenopathy: qualitative and quantitative assessment with power Doppler ultrasound

BACKGROUND: Malignant vascular pathology has traditionally been studied with invasive angiography or in vitro immunohistochemistry. The objective of this study was to investigate the vascular patterns and vascular density of benign and malignant cervical lymphadenopathy using power Doppler ultrasound combined with a computed quantitative image processing system. METHODS: Investigations of 189 cervical lymph node lesions were undertaken prospectively using a 5-10 MHz linear array transducer in power mode. The types of vascular patterns displayed with power Doppler ultrasound, after sweep-scanning over the whole lymph node, were classified as hilar, spotted, peripheral, or mixed. Quantitative assessment of vascularity was made by sampling three parallel planes of each lymph node. A computed image processing system automatically calculated the density of vascular signals (called the "vascularity index" in this study) within the lymph node plane. RESULTS: Malignant lymph node lesions were shown to have higher vascularity indices (0.169+/-0.147, P < 0.01). The vascular patterns of benign lesions were mostly of avascular or hilar type (in 83% of cases). Malignant lesions were characterized by patterns of mixed (47%), spotted (20%), or peripheral type (11%). When vascular pattern (nonhilar type) and vascularity index (maximum > or = 0.09) were combined, the specificity for diagnosing malignant lymphadenopathy was as high as 97%. Variance in tumor vascularity was noted in both the benign and malignant groups. CONCLUSIONS: Power Doppler ultrasound combined with a computed image processing system provided an objective tool for assessing tumor vascularity quantitatively. Using this modality, the vascular pathology of malignant lymphadenopathy was found to be characterized by higher vascular density and aberrant vascular patterns.