We examined the developing synaptic junctions in the rat frontal cortex in cases of fetal alcohol syndrome, the objective being to determine the synapse-mental retardation relationship. On day 21 of gestation, the ultrastructural synaptic junction revealed no obvious differences between the ethanol-exposed and control rats; however, the number of synapses in ethanol-exposed rats was one third that of the controls. The possible relationship between synaptic density in the frontal cortex and mental development has to be considered.
Exocytosis of cortical granules (CGs) and the concomitant electron density changes of the zona pellucida (ZP) in the absence of sperm penetration were investigated in mouse oocytes processed with tannic acid containing fixation at various stages during and after maturation. After fusion of the CG membrane with the plasma membrane, the CG contents became very electron-dense, due to tannic acid. CG material is seen to be made up of coarse granular structures which gradually change to fine amorphous structures, which accumulate within the developing perivitelline space (PVS). When the coarse CG material attaches to the ZP, small domains exhibiting higher electron density appeared, and the number of these domains gradually increased. Release of CG was observed from metaphase I through metaphase II. In metaphase I to immediately after ovulation, the higher electron density of ZP and CG release was restricted to the cortical area overlying the meiotic spindle. Finally, the CG-free domain formed itself overlying the meiotic spindle as a result of CG release. However, in oviductal ova, CG release additionally occurred in the hemisphere opposite the spindle. At this stage the entire PVS was well developed and contained numerous fine electron-dense materials. Moreover, the inner half of the ZP increased in electron density as well. This change in electron density of the ZP might be associated with released CG material. These results suggest that the "partial cortical reaction" may play an important role in conditioning the ZP prior to ZP reaction.
The correlation between the hypo-osmotic swelling test, the modified Eliasson score for human semen analysis and the hamster egg penetration assay was examined. The results showed a weak but significant correlation between the group of subjects with swelling rates below 50% and the above 80% group. These groups showed hamster egg penetration assay rates of 9 +/- 14% and 39 +/- 29%, respectively (P less than 0.035). A significant correlation was also found between modified Eliasson scores (17 +/- 10 and 5 +/- 7, respectively) and swelling rates below 50% and above 70% (P less than 0.001). These results suggest that spermatozoa showing a low swelling rate have a poor fertilizing capacity. Therefore, the swelling tests and analysis of the patients semen can be used to discriminate sperm quality.
We have reported the fine structural (ultracytochemical) localization of the activity of phosphatases related to thiamin metabolism, that is, thiamin monophosphatase (TMPase), thiamin pyrophosphatase (TPPase), and thiamin triphosphatase (TTPase), in the cerebrum and cerebellum of the normal adult rat at the Second Cooperative United States-Japan Seminar on Thiamin in 1974.' In the present investigation we would like to report recent ultracytochemical findings of thiamin phosphatases mainly in the spinal cord of the normal adult rat obtained in our laboratory.In the present investigation the optimal pHs of thiamin phosphatases in fresh homogcnates of several tissues were also biochemically estimated in order to reevaluate the ultracytochemical methods in use. The enzymatic activity remaining in the tissue sections after fixation was also measured biochemically and was compared with that in fresh homogenates.
BIOCHEMICAL ESTIMATION OF OPTIMAL pHs OF THIAMIN PHOSPHATASES I N FRESH HOMOGENATES OF MOUSE TISSUESThe liver, kidney, heart, cerebrum, and spinal cord of the normal albino mouse weighing ca. 30-40 g were used. The fresh, unfixed tissues were homogenized by a Waring blender and homogenates were incubated in the medium for the demonstration of TMPase (TABLE 1) and TPPase'.' (TABLE 2) activities at various pHs from pH 5.0 to pH 9.5. The pH was varied by changing pH of buffers used in the medium. Lead nitrate or lead citrate, capture reagents for the ultracytochemical demonstration of the enzymatic activity, was, however, omitted for the biochemical estimation of activity. Phosphate (P,) liberated was measured spectrophotometrically by the method of Fiske and S~b b a r o w .~ The TPPase activity in homogenates was estimated at pH 6.5 and pH 9.5 for comparison by using the medium listed in TABLE 3, although lead nitrate or lead citrate was similarly excluded. The enzymatic activity was measured in all cases in thc incubation medium with or without 2.5 mM levamisole, an inhibitor of nonspecific alkaline phosphatase.' Incubation was carried out for 30 min a t 37OC. The activity was expressed as pg P,/h/mg fresh tissue.188 0077-8923/82/0378-0l88 $1.75/00 1982, NYAS
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