Hormone-dependent changes of blood vessels in DMBA-induced rat mammary carcinoma and its regression studied by 3H-thymidine autoradiography

Using DMBA-induced rat breast cancer, the changes in the histology and proliferative activity underlying the phenomenon of tumor regression by hormone therapy were studied by 3H-thymidine autoradiography. The control tumor was found to essentially consist of two histologically different areas, medullary (A area) and tubular or cystic (B area). The cancer cells in the A area were homogeneously proliferating with a cell cycle time of 51h, and among those in the B area, 65% were proliferating with a cell cycle time of 81h while 35% were non-proliferating. Among the various-kinds of hormone therapies, ovariectomy plus male sex hormone administration was most effective in inducing tumor regression. In the regressed tumor, the A area was greatly diminished due to central necrosis and replaced by cystic B area. In the remaining A area, the cell cycle time was lengthened to 97h, and that for the proliferating cells in the B area was as long as 118h. The most striking histological change after ovariectomy plus male sex hormone administration was the diffuse necrosis of the capillary endothelial cell within 24h, followed by hemorrhage, central necrosis in the A area (1W), and final stage of fibrosis (2W). The tumor administered with female sex hormone after ovariectomy showed a rebound growth from the regression, due to the initial reactivation of the endothelial cell proliferation and following stimulation of cancer cell mitotic activity. From these observations, it is concluded that the capillary endothelial cells in DMBA-induced rat breast cancer are estrogen dependent, and that the tumor regression induced by decreased estrogen-level is attributable to the massive necrosis from capillary insufficiency and anoxia.     

Detection of varicella-zoster virus DNA by field-inversion gel electrophoresis

A new method for detection of varicella-zoster virus (VZV) DNA using field-inversion gel electrophoresis (FIGE) was devised. VZV-genomic DNA could be differentiated from the host cell DNA of human embryonic lung (HEL) fibroblasts infected with VZV under electrophoretic conditions allowing resolution of linear and double-stranded DNAs in the 49-230 kilobase pairs (Kb) range. The detection of VZV-genomic DNA from infected HEL cells was successful regardless of whether the VZV was a laboratory strain, live vaccine strain, or fresh isolate. Under the same electrophoretic conditions, DNA of VZV-infected HEL cells could be clearly differentiated from DNA obtained from HEL cells infected with herpes simplex virus type 1 (HSV-1), type 2 (HSV-2), or human cytomegalovirus (HCMV). Furthermore, VZV genomic DNA could be detected from as small a sample as 1.9 x 10(4) VZV-infected HEL cells. Finally, we could detect VZV genomic DNA from 10 samples of vesicle tissue (blister lids, each about 1-4 mm2) and one sample of vesicle fluid (about 5 microliters) obtained from patients diagnosed as having herpes-zoster. The results of this study indicate that FIGE is a simple and promising method for the detection of VZV from clinical materials as well as infected in vitro cultured cells.     

Structure of comblike teeth of the ayu sweetfish,Plecoglossus altivelis (Teleostei: Isospondyli): I. Denticles and tooth attachment

The structure and tooth attachment of the comblike teeth and denticles of the ayu sweetfish, Plecoglossus altivelis, were examined by light and scanning electron microscopy. The denticle is composed of a spoonlike crown with a spine pointed anteriorly, a triangular plate in the cervical region, and a root that curves laterally and tapers off to a point. The root apex is fused with a long thin pedicle that turns abruptly anteriad toward the jaw bone. Planes of the spine, the spoonlike crown, the triangle plate and the root of the denticle are varied, and the denticle is twisted in the region of the triangle plane. The superficial layer of the dentine is homogeneously calcified and is considered to be enameloid, because some of the inner dentinal epithelial cells in the tooth germ are columnar and possess cellular processes at their apical ends. The dentine is fibrous and fine dentinal tubules are visible in dentine treated with sodium hydroxide and observed by scanning electron microscopy. The upper half of the root is surrounded by a dense layer of collagen fibers running parallel to the tooth axis, and the lower half is encompassed by interlaced collagen fibers. The lower part of the root is open on its lingual side. The pedicle is a long rod which is homogeneously calcified and enmeshed by interlaced collagen fibers, and it curves mediad as it nears the jaw bone. The pedicles are interposed between a layer of gelatinous connective tissue and the jaw bone and terminate on the periosteum. Comparative aspects of ayu tooth morphology are discussed. © 1993 Wiley-Liss, Inc.     

Urinary excretion of LATS in a patient with Graves' disease complicated by nephrotic syndrome

A case report of a female patient with Graves' disease complicated by nephrotic syndrome with high LATS activity in urinary gamma-globulin is presented. When in the hyperthyroid state with high LATS activity in the serum, she was treated with antithyroid drugs, excess iodine, and finally radioisotopes. Mild hypothyroidism occurred transiently without any significant change in serum LATS activity. Nephrotic syndrome suddenly appeared. Urinary IgG was purified by salting out with ammonium sulfate, DEAE and protein A-Sepharose, and LATS activity in the purified urinary IgG fraction was demonstrated. The specific activity of LATS activity in urinary IgG protein was slightly lower than that of the serum. This case is the first demonstration of LATS activity in urine from a patient with hyperthyroidism and nephrotic syndrome.     

Elevated immunoreactive beta-endorphin level in ventricular fluid after analgesic electrical stimulation of posteromedial hypothalamus

Immunoreactive beta-endorphin (beta-EP) in the ventricular fluid of six carcinomatous patients was measured using a specific radioimmunoassay. The subjects were undergoing a surgical procedure for relief of chronic intractable pain. This procedure involved the focal stimulation and coagulation of the posteromedial hypothalamus. Samples of ventricular fluid were collected before and after the stimulation and serially after the coagulation. Prior to stimulation, beta-EP-like immunoreactivity (beta-EP-LI) was below 200 pg/ml. In all of the six patients with pain relief, electrical stimulation led to a marked increase in immunoreactive beta-EP. In three patients beta-EP levels remained high after electrical coagulation for 6-24 hrs. These results suggest that beta-EP-like material, released into the ventricular fluid, may contribute to the initial pain blockade that results from stimulation and coagulation of the posteromedial hypothalamus.     

Purification and Characterization of Vibrio vulnificus Protease

A protease was purified from a strain of Vibrio vulnificus isolated from the blood of a septicemic human. The vibrio was cultured in bacto peptone-yeast extract medium, and the protease was purified by a purification procedure including ultrafiltration of the culture supernatant with an Amicon YM 5 membrane, diethylaminoethyl-Sephacel column chromatography, Sephacryl S-200 column chromatography and fast protein liquid chromatography on Mono Q column. The protease preparation revealed homogeneity on polyacrylamide gel electrophoresis and about 30,000-fold purification was achieved, with a yield of about 30%. The isoelectric point of the purified V. vulnificus protease was about 5.80 and its molecular weight was ca. 45,000 by sodium dodecyl sulfate polyacrylamide gel electrophoresis. The optimum pH of the protease activity was 8.0. The V. vulnificus protease was inhibited by a metalloprotease inhibitor and zinc ion and/or ferrous ion were essential for its enzyme activity. No cysteine residue was detected in the V. vulnificus protease. The protease had caseinolytic, elastolytic and collagenolytic activities.     

Effects of nickel ion on the conduction of action potentials in non-myelinated nerve fibre of crayfish.

Effects of NiCL2 and PCMB (p-chloromercuribenzoate) on the action potential were examined by the method of extra- and intracellular electrodes, using a single nerve fibre of crayfish. The results obtained were as follows : The conduction of the action potential was blocked by treating the nerve fibre with Ni ion or PCMB. The blockade was easily recovered by replacement with cysteine. The process of the blockade and recovery, which could be repeated several times, was fairly characteristic such that the more repetition led the sooner blockade and the harder recovery. No conduction block was observed by treatment with Ni-cysteine mixed solution nor with PCMB-cysteine solution. The critical concentration for blocking was 1.1 x 10(-4)M for NiCL2 and 5.6 x 10(-6) M for PCMB. The action potential was disappeared without any change in the resting potential by treatment with the chemicals, which gave significant effects on the rising and falling phases of the action potential before the blockade.     

Scanning electron microscope observation of the dog mesenteric lymph node

Summary The perfused large mesenteric lymph node of the dog was observed under the scanning electron microscope.The lymph sinus contains reticulum cells which mostly are two-dimensionally formed stellate plates oriented in a uniform direction. Large round macrophages are loosely fixed by the reticulum cell processes. No intermediate type between both cells has been observed. Macrophages having a few long tentacle-like projections are densely covered by clubbed cytoplasmic processes. Smaller round cells, probably plasma cells and lymphocytes also remained in the sinus.The pulp of the node is built up by reticulum cells, much smaller than those in the sinus, and by densely packed round cells including a few macrophages.The trabeculae and the reticulum of the nodal parenchyme form a continuous structure.Cordial thanks are expressed to Dr. Toshihiro Ishii, Professor of Anatomy of the Tohoku University Medical School, for his valuable advice. Thanks are also due to the kind cooperation of Mr. Akira Kubotsu of the Central Research Laboratories, Kuraray Co. Ltd.     

A new synthesis of purine arabinosides by a combination of chemical and enzymatic reaction

The synthesis of hypoxanthine, 2-chlorohypoxanthine, and 2-methylhypoxanthine arabinoside by an enzymatic transarabinosylation and their chemical conversion to biologically interesting purine arabinosides are described. Some of the synthesized compounds were tested for the inhibition of DNA synthesis in cultured tumor cells.