SUMMARYWhen athymic nude (nu/nu) and heterozygous littermate (nu/+) mice were injected intraperitoneally (i.p.) with a mouse-adapted strain of dengue virus (DV), the following differences were noted in the course of infection. (i) The average survival time of nu/nu mice was longer than that of nu/+ mice, although the mortality ratios were not significantly different. (ii) DV persisted in some of the nu/nu mice for long periods of time without exhibiting any symptoms but they died after prolonged incubation periods. These aspects were not observed in the nu/+ mice. (iii) Infected nu/nu mice produced IgM antibody only transiently in the early stage of infection but they did not subsequently show regular IgG antibody production which normally occurred in nu/+ mice. (iv) Piamatral and perivascular mononuclear cell infiltration in the infected brain was more intense in nu/+ than in nu/nu mice. It is suggested from these data that the course of DV infection in mice is affected by the availability of thymus-derived lymphocytes (T-cells).Infectious virus was detected in various organs and tissues of infected mice. The hearts of nu/nu mice tended to show higher virus titres than those of nu/+ mice, whereas the virus concentrations in the brain, skeletal muscle and lymph node were the same in both groups of mice. Specific DV antigen was revealed by the fluorescent antibody (FA) technique in cells located in the infected tissues.

A 45‐year‐old housewife sustained a blow to the occipital region In a traffic accident about 2 years and 3 months prior to death. Autopsy revealed lesions of softening in the hypothalamus, left thalamus, frontal lobe (especially on the left), and base of the left temporal lobe. Following the head trauma, a marked Increase of appetite was noted, with obesity, hypogonadism, and mild elevation of temperature. No diabetes insipidus was noted whatsoever. Based on data from physical and pathological examination, the relationship between function and morphology in the human hypothalamus was discussed.

Water-soluble polymer compound, polyvinyl alcohol(PVA), and water-insoluble polymer compounds, polyvinyl acetate (PVAc) and polystylol (PS), were administered in 297 rabbits. When high polymerized PVA, PVAc or PS were continuously injected intravenously for a long period of time, lesions resembled to those of Gaucher and Niemann-Pick diseases were developed. From these experimental results, pathological development of various sphingolipidoses found in the human body was discussed and pathological findings were analysed polymer-chemically from the chemical properties of the substances stored.

Dengue virus (DV) is known to replicate in the brain tissue of mice when injected intracerebrally. However, other organs and tissues do not easily support the replication of DV. We have reported that a highly mouse-adapted strain of DV caused acute lethal infection in mice even when injected intraperitoneally (ip), and that host responses to DV infection, i.e., antibody production and mononuclear cell infiltration in the infected brain, were different in athymic nude (nul nu) mice and in their heterozygous littermates (nu/+) (6). Viral replication was detected not only in the brain but also in other organs and tissues of both kinds of mice. In this paper we present additional data, particularly on the morphological aspects such as localization of DV in the infected mice.DV type 1, Mochizuki strain (7), in the form of the supernatant of suckling mouse brain homogenates, was used. Four to six-week-old male Balbjc-nu/nu and nul+ mice were procured from Japan Clea Co., Ltd. Each mouse was inoculated ip with 10 7 • 0 to 10 7 • 8 plaque-forming units (PFU) of DV. At fixed times thereafter, each mouse was bled and the organs were removed. The organs were then divided into two or more portions, which were used for virus titration and histological examination, including hematoxylin-eosin (HE), periodic acid-Schiff (PAS), and indirect fluorescent antibody (FA) stains as well as electron microscopic (EM) observation. Figure I shows the growth curve and concentration of virus in the brain, skeletal muscle and heart of infected nu/nu mice.The virus was first clearly detected 4 days after infection, increased in amount and reached maximum titers at the time paralysis appeared. In the paralyzed mice, the highest virus titers were found in the brain (ca. 10 8 PFUIg), and the second highest in the skeletal muscle and heart (ca. 10 4 PFUIg). Our previous findings that the virus concentration in the heart of nu/nu mice was higher than in nul+ mice (6) were repeatedly confirmed. Lymph node, lung, liver, spleen and kidney also contained virus, although the titers varied from one sample to another. In our previous experiments it was not certain whether the virus content in the lymph node and spleen were of the same level or not, but the present studies clearly indicate that the infected lymph node had a higher concentration of virus than the spleen (Fig. 2).

A 6‐month‐old boy, having suffered repeated convulsive seizures since birth, died of severe epilepsy, the disease remaining unknown. However, when a brother, born after the death of the present case, displayed the same clinical symptoms and was diagnosed clinically as having pyridoxine dependent convulsion, the deceased became suspected of having been a case of familial pyridoxine dependency. Pathologically, bilateral cerebellar hemorrhages were found accompanied by subdural and subarachnoidal hemorrhages. Histologically, neuronal loss and diffuse astrocyte hyperplasia were found hi the brain: Beside marginal gliosis, proliferations of astroglia and glial fibers were found, especially hi the pons, medulla oblongata, and cervical cord, although the fibrillary gliosis may be representative for a physiological intermediate state. Foamy cells were found in the lymph nodes, but not hi the brain. Observed hi the kidneys were substances deposited hi the glomeruli and Bowman's capsules and materials hi the tubular lumen.