A morphological study of the efferent ducts of the human epididymis

Efferent ducts of the human epididymis were studied with a light microscope and a computerized three-dimensional image analyser by preparing complete serial sections. The efferent ducts were characterized by a columnar epithelium, which differed both from the cuboidal epithelium of the rete testis and from the tall columnar epithelium of the epididymal duct. Therefore, the junctions of the efferent ducts with the rete testis and epididymal duct could be identified morphologically. Five or six efferent ducts originated from the dilated extra-testicular rete testis, ran in an extremely tortuous manner and transformed into the epididymal ducts in an end-to-end pattern near the border of the epididymal head and corpus. Computerized image analysis confirmed light microscopical findings and demonstrated three-dimensional structures of the junctions of the efferent ducts with both the rete testis and the epididymal ducts.     

Collaborative Behavioral Teratology Study of Phenytoin: A Test Battery for Neurobehavioral Developmental Toxicity in Rats.

Abstract: At the Behavioral Teratology Meeting (BTM) of the Japanese Teratology Society in 1992, a core test battery was proposed from a practical and simple point of view as an estimation of developmental neurobehavioral toxicity for use in pharmaceutical drug screening. The validity of the core test battery is being examined in a new series of collaborative studies. The present study is the first such study; phenytoin, a well-known behavioral teratogen, was selected as the test compound, and 32 laboratories took part in a behavioral teratology study of phenytoin using the new test battery. Sprague-Dawley strain rats from four breeds were used. Phenytoin (200 mg/kg) was administered orally to pregnant rats from days 10 to 14 of gestation (sperm detection = day 0), and in the male offspring, the survival rate, development of physical landmarks, functional developments, open field test scores, and Biel water maze test results were assessed and the brain weights were measured. The shuttle box conditioned avoidance test was also performed in some laboratories. In the present collaborative study, by taking an aggregate of the relative values converted from the measured values of each breed (providing a much larger sample size than that recommended by reproduction toxicity study guidelines), a high detectability level for phenytoin's effects was established. Under these conditions, the effects of phenytoin on eye opening, incisor eruption, the surface righting reflex, the negative geotaxis reflex, and performance of the open field test, Biel water maze test and shuttle box conditioned avoidance test were observed. It was found that present collaborative study made it possible to evaluate the detectable capacity of each of these test battery items. In addition, the critical period of abnormalities demonstrated in many test items was identified, and the results of several previous reports were confirmed. Furthermore, a breed difference in the effect of phenytoin for several test items was found. The present results established that the core test battery accurately detected the effects of phenytoin.     

The use of a DNA stabilizer in human dental tissues stored under different temperature conditions and time intervals

Objective

The present study evaluated the use of a reagent to stabilize the DNA extracted from human dental tissues stored under different temperature conditions and time intervals.

Material and Methods

A total of 161 teeth were divided into two distinct groups: intact teeth and isolated dental pulp tissue. The samples were stored with or without the product at different time intervals and temperature. After storage, DNA extraction and genomic DNA quantification were performed using real-time PCR; the fragments of the 32 samples that represented each possible condition were analyzed to find the four pre-selected markers in STR analysis.

Results

The results of the quantification showed values ranging from 0.01 to 10,246.88 ng/μL of DNA. The statistical difference in the quantity of DNA was observed when the factors related to the time and temperature of storage were analyzed. In relation to the use of the specific reagent, its use was relevant in the group of intact teeth when they were at room temperature for 30 and 180 days. The analysis of the fragments in the 32 selected samples was possible irrespective of the amount of DNA, confirming that the STR analysis using an automated method yields good results.

Conclusions

The use of a specific reagent showed a significant difference in stabilizing DNA in samples of intact human teeth stored at room temperature for 30 and 180 days, while the results showed no justification for using the product under the other conditions tested.