Koshi Mochizuki

Studies on the activity of obioactin with acetylspiramycin on mice infected with toxoplasma gondii

In acutely infected mice, acetylspiramycin (ASPM) administered in combination with Obioactin , or sulfamethoxypyrazine ( SMPZ ), prevented Toxoplasma organisms from encysting in the brain and heart tissues. When administered alone, ASPM prevented these organisms from encysting in the heart but not in the brain. All the regimens used failed to reduce the bulk of parasites in the brain and heart tissues of chronically infected mice. Treatment with an ASPM- Obioactin combination, however, brought about the most remarkable reduction, or 52.4%, of the cyst count in the brain of all the methods of treatment applied. Light and electron microscopy of the mice with chronic Toxoplasma infection revealed no changes in the brain or heart tissue of the ASPM- Obioactin treated mice and degenerative changes in the cyst wall and bradyzoites and a remarkable increase of microglias with cysts in the brain in some of these mice.

Analysis of Metopirone-Induced Hypertrophy of Adrenals in Fetal Rats Encephalectomized in Utero

Abstract Pregnant rats were treated with 30 mg metopirone (M) each day for 2 days and autopsied on the third day in various gestational periods (Days 18-20, 19-21, and 20-22). Control rats were treated with saline alone (S). The adrenals of intact fetuses in M-treated dams were significantly heavier than those of intact fetuses in S-treated dams in every experimental period. In both M- and S-treated dams, the adrenals of encephalectomized (E) fetuses were lighter than those of intact littermates. However, in the experimental period of Days 18-20 and 19-21, the adrenals of E fetuses in M-treated dams were slightly but significantly heavier than those of similar E fetuses in S-treated dams. In contrast, in the experimental period Days 20-22, there was no significant difference in the weight of adrenals of E fetuses of M- and S-treated dams. These changes in fetal adrenal weight were reflected histologically in parallel changes in the size of adrenocortical cells. The observations suggest that the fetal adrenal hypertrophy following maternal treatment with metopirone can occur to some extent independent of the fetal brain, but that close to the end of gestation the hypertrophy occurs completely under the control of the fetal brain.

Influences of hypophysectomy in mice

In order to clarify the normal involutionary changes in the reproductive organs and adrenals which occur as a results of hypophysectomy, a histological study on these organs of hypophysectomized female mice was performed. Twenty immature and 28 mature mice of the bc strain were subjected hypophysectomy and autopsied at various periods ranging from 1 to 150 days after hypophysectomy. the operation the immature mice were 28 to 30 days of age, and the mature ones 2 months of age. autopsy, the organs to be studied were all dissected from the surrounding fatty connective tissue, weighed and prepared for histological studies. The fixatives and staining methods employed were the same as those described in our previous reports, except for some cases in which the organs were fixed in chilled 80% alcohol and stained for alkaline monoglycerophosphatase by Gomoris technic.Following hypophysectomy there was a fall in boby weight. The reproductive organs and adrenal glands regressed in weight and underwent a pronounced atrophy. The changes in organ weights are summarized in tables 1 and 2.Ovaries: A very rapid regression in size of ovaries took place. Thus there has been a loss of some 50% in weight on the 10th day after hypophysectomy. The first structures to show significant changes after hypophysectomy were large and medium sized follicles. Signs of atresia began to be seen as early as 24 hours, showing clumping of chromatin and achromatolysis of the granulosa cells. Later the thecal cells underwent atrophy, the ovum degenerated and on the 5th day no large follicles remained. Small follicles showed a gradual decrease in number and very few were seen on the 25th day, the ovary becoming to be filled with stromal cells. However, growth of the primordial follicles did not cease. They might develop to the beginning stage of antrum formation, because in the granulosa cells of the small follicles, although not numerous, mitosis were often seen. In the ovaries of prepuberally operated mice, pituitary defficiency manifestations were also evident. Since abvanced stages of follicular maturation did not occur in any case. The most interesting fact about alkaline phosphatase which has emerged from this study is that all follicles of varying size develop large quantities of the enzyme in the granulosa layer which is normally almost devoid of activity.Ovarian stroma: The ovarian stroma of the operated mice was composed of a highly cellular tissue with densely staining nuclei. The nuclei underwent a retrogressive process designated as “wheel cell formation”.Corpora lutea: When corpora lutea were present, a process of degeneration began within 5 days and ended by the 20th day after the operation. Corpora lutea of pregnancy in the mice operated at midpregnancy, however, looked quite normal at the end of gestation.Uterus and Vagina: After the operation the uterus atrophied to a small and compact structure, very similar to that found in the spayed animals. The vaginal epithelium underwent a pronounced atrophy and the epithelium consisted of two layers of cells only.Adrenal gland: The adrenal glands underwent cortical atrophy in a marked degree and their individual cells decreased in size. The histological changes produced by hypophysectomy in the adrenal glands were almost the same as those described in our previous papers, but were somewhat prominent in females. It is of considerable interest that after operation alkaline phophatase developed in the adrenal medullary cells, which is normally devoid of activity in them.