Acta Medica Okayama 41巻 4号

Concentrations of homovanillic acid (HVA) and 5-hydroxyindoleacetic acid (5-HIAA) were measured in human cerebrospinal fluid (CSF) following long-term storage at -20 degrees C for intervals of three to 60 months. No significant changes in HVA levels were detected in CSF stored for up to 60 months. On the other hand, 5-HIAA concentrations remained stable for up to 6 months, but decreased significantly in the specimens stored for longer time intervals. The results indicate that 5-HIAA should be determined within 6 months after CSF collection, while HVA determinations may be delayed.

Concanavalin A (Con A) induced cap formation in rat ascites hepatoma cells (AH7974). In these Con A-treated cells, the association of cytoplasmic proteins with cell membranes was suggested by observing their Triton shells. The transition from G-actin to F-actin occurred in these cells. The association of membrane lipid with cytoplasmic proteins extracted from AH cells was studied by the isolation of protein-bound liposomes and phase transition release. The analysis of isolated liposomes revealed that many cytoplasmic proteins which specifically associated with liposomes were cytoskeletal elements including F-actins. The association of proteins with liposomes was affected by the lipid composition of the liposomal membrane and by the Ca2+ concentration of the incubation medium. The strong interaction of liposomal membrane with cytoplasmic proteins or isolated cytoskeletal proteins was demonstrated also by phase transition release using carboxy fluorescein-containing liposomes. These experiments showed that there was a strong affinity between lipid membrane and cytoskeletal elements including F-actins and that the amount of F-actin increased due to Con A treatment. The association of the submembranous microfilaments with the cell membrane may contribute to capping of the cells caused by Con A.

The paravestibular canaliculus was studied by light microscopy in serial sections of the temporal bones from otosclerotic patients who underwent fenestration or stapes surgery. In all examined 23 specimens (13 cases), the endolymphatic duct and sac were observed to be normally developed with no pathological findings. The paravestibular canaliculus was found in 14 of the specimens (60.9%). Its course was traced from the proximal to the distal area in 12 specimens, and it appeared to merge into the distal portion of the endolymphatic sac in 7 of them. Twelve of the paravestibular canaliculi contained one vein, and 3 contained several veins. No artery was found. The paravestibular canaliculus was observed to originate from small vascular channels around the vestibule in the otic capsule, lateral to and near the internal aperture of the vestibular aqueduct.

Titers of antibody against Escherichia coli in human milk and in the sera of 11 breast-fed infants, 6 bottle-fed infants and 9 infants in the post-weaning period were measured by the passive hemagglutination method. High antibody titers were observed in human milk in the first 4 days after parturition, but the titer decreased rapidly thereafter. None of the healthy, breast-fed infants had detectable serum antibodies, while a breast-fed infant with a perianal E. coli abscess had antibodies. On the other hand, 4 of the 6 bottle-fed infants and all of the 9 infants in the post-weaning period had antibodies. The significance of these results was discussed.

The cytostatic and cytotoxic effects of highly purified natural human tumor necrosis factor (HuTNF-alpha) and natural human interferon-alpha (HuIFN-alpha) on 23 cell lines were studied in vitro. Natural HuTNF-alpha showed cytostatic and cytotoxic effects on PC-9, KHG-2, HT-1197, KG-1 and L-929 cells, and HuIFN-alpha showed both effects on KHG-2 and Daudi cells. A mixture of HuTNF-alpha and HuIFN-alpha (1:1, by unit) showed cytostatic and cytotoxic effects on HuTNF-alpha- or HuIFN-alpha-resistant cell lines such as KB, KATO-III, HEp-2, P-4788, as well as on HuTNF-alpha- or HuIFN-alpha-susceptible cells. Thus, the combined preparation of HuTNF-alpha and HuIFN-alpha expanded the spectrum of sensitive cells. The dosage of the mixed preparation required to produce 50% inhibition of cell growth was less than 20% of that of HuTNF-alpha or HuIFN-alpha alone. These results indicate that the cytostatic and cytotoxic effects of HuTNF-alpha and HuIFN-alpha are synergistically enhanced when they are administered together.

Blood vascular beds of fetal, adult and aged human kidneys were reproduced with methyl methacrylate and observed with a scanning electron microscope. The kidney glomeruli, including those from the fetal kidneys, had anastomosing capillaries. The glomeruli in the kidneys of an aged person contained many more capillaries which were much more tortuous than those of the adult and fetal kidneys. Furthermore, it was observed that the glomeruli in the kidneys of the aged person usually received tortuous afferent vessels and frequently emitted multiple efferent arterioles. The glomeruli in the juxtamedullary layer of the kidneys of the aged person were rather small in size and contained degenerative capillary networks. This observation suggests that the medulla of the kidneys of the aged is poorly supplied with blood.

Rat kidney glomerular basement membrane (GBM) was isolated and digested with alpha-amylase and elastase. Electron microscopy revealed a meshwork structure composed of fibrils 3 nm in width. They appeared to be type IV collagen fibrils. We succeeded in clarifying a significant ultrastructural aspect of the GBM which had been unclear until now. The findings are consistent with our previously proposed GBM molecular sieve theory.