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Biomedical subjects

J Koike

Publications and source records attributed to J Koike.

At least 73 records · Page 4Linked to original sources
PubMed1996

Correlation between intrasinusoidal neutrophilic infiltration and ceroid-lipofuscinosis in alcoholic liver fibrosis with or without fatty change: clinicopathological comparison with nutritional fatty liver.

A histopathological study was conducted on alcoholic liver fibrosis with fatty change (21 cases) and alcoholic liver fibrosis without fatty change (18 cases) in comparison with nutritional fatty liver (27 cases). The diagnoses of alcoholic liver fibrosis groups were clinically fulfilled according to the criteria established by the Alcohol and Liver Research Group (Chief: Professor Takeuchi) of the Ministry of Education of Japan. Histological diagnosis of alcoholic liver fibrosis with fatty change was based on moderate and/or greater fatty metamorphosis of the hepatic lobules, alcoholic liver fibrosis without fatty change on a lesser degree of fatty metamorphosis than alcoholic liver fibrosis with fatty change, and nutritional fatty liver on clinicopathological features. All 66 cases were negative for viral markers of hepatitis B surface antigen and anti-hepatitis C virus in serum. Intrasinusoidal neutrophil infiltrations were significant in cases of alcoholic liver fibrosis groups more often than in cases of nutritional fatty liver. The degree of intrasinusoidal neutrophil infiltration in cases of alcoholic liver fibrosis groups was higher in cases who had last consumed alcohol recently, compared with those with longer abstinence. In alcoholic liver fibrosis with fatty change and nutritional fatty liver groups, mild-to-moderate degrees of ceroid-lipofuscinosis were recognized, but both fatty change and ceroid-lipofuscinosis were decreased according to the deterioration of fibrotic changes in alcoholic liver fibrosis with fatty change cases. On the other hand, it is significant that the frequency of ceroid-lipofuscinosis in alcoholic liver fibrosis without the fatty change group was lower than those of the alcoholic liver fibrosis with fatty change and nutritional fatty liver groups. Distribution of ceroid-lipofuscinosis has a tendency to be recognized around the central zone (zone III) of alcoholic liver fibrosis with fatty change cases with mild fibrosis, as in nutritional fatty liver cases, and the ceroid-lipofuscinosis disperses with the progression of fibrosis. These results suggest that fibrosis and fatty droplet deposition lead to microvascular heterogeneity. Therefore, the degree and distribution of fatty droplets, ceroid-lipofuscinosis, and intrasinusoidal neutrophil infiltration differ, depending on the etiology of fatty liver, and are an important histopathological barometer in cases of alcoholic liver fibrosis with fatty change and alcoholic liver fibrosis without fatty change, thus indicating the degree of fibrosis and the period since last alcohol intake.

Adult↗
PubMed1995

Formation of amino acid precursors in cometary ice environments by cosmic radiation.

Cometary ices are believed to contain water, carbon monoxide, methane and ammonia, and are possible sites for the formation and preservation of organic compounds relating to the origin of life. Cosmic rays, together with ultraviolet light, are among the most effective energy sources for the formation of organic compounds in space. In order to study the possibility of the formation of amino acids in comets or their precursory bodies (interstellar dust grains), several types of ice mixtures made in a cryostat at 10 K ("simulated cometary ices") were irradiated with high energy protons. After irradiation, the volatile products were analyzed with a quadrupole mass spectrometer, while temperature of the cryostat was raised to room temperature. The non-volatile products remaining in the cryostat at room temperature were collected with water. They were acid-hydrolyzed, and analyzed by ion-exchange chromatography. When an ice mixture of carbon monoxide (or methane), ammonia and water was irradiated, some hydrocarbons were formed, and amino acids such as glycine and alanine were detected in the hydrolyzate. These results suggest the possible formation of "amino acid precursors" (compounds yielding amino acids after hydrolysis) in interstellar dust grains by cosmic radiation. We previously reported that amino acid precursors were formed when simulated primitive planetary atmospheres were irradiated with cosmic ray particles. It will be of great interest to compare the amount of bioorganic compounds that were formed in the primitive earth and that brought by comets to the earth.

Amino Acids↗
PubMed1995

Formation of bioorganic compounds in planetary atmospheres by cosmic radiation.

Simulated planetary atmospheres (mixtures of simple gases) were irradiated with high energy particles to simulate an action of cosmic rays. When a mixture of carbon monoxide, nitrogen and water was irradiated with 2.8-40 MeV protons, a wide variety of bioorganic compounds including amino acids, imidazole, and uracil were identified in the products. The amount of amino acids was proportional to the energy deposit to the system. Various kinds of simulated planetary atmospheres, such as "Titan type" and "Jovian type", were also irradiated with high energy protons, and gave amino acids in the hydrolyzed products. Since cosmic rays are a universal energy source in space, it was suggested that formation of bioorganic compounds in planetary atmospheres is inevitable in the course of cosmic evolution.

Amino Acids↗
PubMed1995

Studies in the search for life on Mars.

The ability of living organisms to survive extraterrestrial conditions has implications for the origins of life in the solar system. We have therefore studied the survival of viruses, bacteria, yeast, and fungi under simulated Martian conditions. The environment on Mars was simulated by low temperature, proton irradiation, ultraviolet irradiation, and simulated Martian atmosphere (CO2 95.46%, N2 2.7%, water vapor 0.03%) in a special cryostat. After exposure to these conditions, tobacco mosaic virus and spores of Bacillus, Aspergillus, Clostridium, and some species of coccus showed significant survival.

Aspergillus niger↗
PubMed1995

Immunohistochemical localization of V2 vasopressin receptor along the nephron and functional role of luminal V2 receptor in terminal inner medullary collecting ducts.

We investigated immunohistochemical localization of V2 vasopressin receptor along the nephron using a specific polyclonal antibody. Staining was observed in some of thick ascending limbs and all of principal and inner medullary collecting duct (IMCD) cells. Not only basolateral but also luminal membrane was stained in collecting ducts, especially in terminal IMCD (tIMCD). To learn the functional role of luminal V2 receptor in tIMCD, we studied the luminal effects of arginine vasopressin (AVP) on osmotic water permeability (Pf), urea permeability (Pu), and cAMP accumulation using isolated perfused rat tIMCD. In the absence of bath AVP, luminal AVP caused a small increase in cAMP accumulation, Pf and Pu, confirming the presence of V2 receptor in the lumen of tIMCD. In contrast, luminal AVP inhibited Pf and Pu by 30-65% in the presence of bath AVP by decreasing cAMP accumulation via V1a or oxytocin receptors and by an unknown mechanism via V2 receptors in the luminal membrane of tIMCD. These data show that V2 receptors are localized not only in the basolateral membrane but also in the luminal membrane of the distal nephron. Luminal AVP acts as a negative feedback system upon the basolateral action of AVP in tIMCD.

Amino Acid Sequence↗
PubMed1995

[An immunohistochemical study of the relationship between p53 expression and the DNA ploidy pattern using image cytometry in colorectal carcinoma].

We studied p53 expression in 46 colorectal carcinomas by immunohistochemistry. We examined the relationship between p53 expression and the pathological findings, the prognosis and tumor proliferative activity by Ki-67 staining or DNA ploidy pattern using an image cytometer. Expression of p53 was observed in 41.3% of carcinomas. No correlation was found between p53 expression and the depth of invasion, lymph node metastasis or Dukes' stage. No difference in survival was found between p53 positive and negative patients after curative surgery. We also studied the DNA ploidy pattern using an image cytometer in 28 carcinomas. Aneuploidy was found more frequently in the p53 positive areas than in the negative ones, but there was no significant difference. The DNA index showed no difference between the p53 positive and negative areas. We examined proliferating activity using Ki-67. There was no difference in the Ki-67 labeling index between p53 positive and negative areas. In the present study, there was no correlation between p53 expression and pathological findings, prognosis, tumor proliferative activity using Ki-67 staining or DNA ploidy pattern. Thus, p53 expression was suggested to have little relationship to grade of malignancy.

Cell Division↗
PubMed1994

Induction of superoxide anion production from monocytes an neutrophils by activated platelets through the P-selectin-sialyl Lewis X interaction.

Activated platelets expressing P-selectin on their surface are known to adhere to monocytes and neutrophils. We examined the possibility that the leukocytes were activated by their adhesion to activated platelets and demonstrated that P-selectin-dependent platelet adhesion to neutrophils and monocytes induced production of extracellular superoxide anion (O2-) by these leukocytes. Leukocyte membrane glycoproteins containing Ser/Thr-linked carbohydrate chains were responsible for the signal reception leading to the leukocyte activation. Cytokines were shown to influence these processes. For example, treatments of neutrophils with interleukin-8 (IL-8) or granulocyte colony-stimulating factor (G-CSF) potentiated the P-selectin-induced O2- production. Furthermore, interleukin-1 (IL-1) and interferon-gamma (IFN-gamma) induced surface expression of P-selectin on platelets in the presence of a low concentration of thrombin and consequently enhanced their adhesion capacity to leukocytes. These results indicated that the adhesion of activated platelets to the leukocytes through the interaction between P-selectin and its carbohydrate ligand, sialyl Lewis X (LeX), was a crucial step for the activation of leukocyte function and supported the notion that activated platelets were actively involved in the inflammatory processes.

Blood Platelets↗
PubMed1994

[Study on relationship between intratumoral DNA heterogeneity and clinicopathological findings in colorectal cancer].

We studied the relationship between intratumoral DNA heterogeneity and clinicopathological findings in 85 colorectal cancers. DNA ploidy was analyzed in 5 specimens from different sites of each tumor. When the difference in the DNA index (D.I) between several peaks in the same tumor was more than 0.1, the tumor was considered to consist of heterogeneous subpopulations with different DNA clones. DNA heterogeneity was found in 34 cases (40.0%). There was no relationship between DNA heterogeneity and depth of tumor invasion, lymph node metastasis or stage. The incidence of heterogeneity was significantly higher in the tumor with lower differentiation, liver metastasis or vessel invasion.

Colorectal Neoplasms↗
PubMed1993

Planetary quarantine in the solar system. Survival rates of some terrestrial organisms under simulated space conditions by proton irradiation.

We have been studying the survival rates of some species of terrestrial unicellular and multicellular organism (viruses, bacteria, yeasts, fungi, algae, etc.) under simulated interstellar conditions, in connection with planetary quarantine. The interstellar environment in the solar system has been simulated by low temperature, high vacuum (77 K, 4 x 10(-8) torr), and proton irradiation from a Van de Graaff generator. After exposure to a barrage of protons corresponding to about 250 years of irradiation in solar space, tobacco mosaic virus, Bacillus subtilis spores, Staphylococcus aureus, Micrococcus flavus, Aspergillus niger spores, and Clostridium mangenoti spores showed survival rates of 82, 45, 74, 13, 28, and 25%, respectively.

Bacteria↗
PubMed1993

Effect of urodilatin on cGMP accumulation in the kidney.

Urodilatin is found in the urine and is thought to be produced in the kidney. The effect of urodilatin on cGMP accumulation in the kidney was investigated. cGMP accumulation by urodilatin and atrial natriuretic peptide (ANP) were compared with tubule suspensions from renal cortex, outer medulla, inner medulla, and microdissected nephron segments. Urodilatin-stimulated cGMP accumulation was higher in tubule suspensions from the inner medulla than in those from the cortex and outer medulla. The highest accumulation stimulated by 10(-6) M urodilatin among nephron segments was observed in glomeruli and inner medullary collecting ducts (IMCD). Small accumulations were seen in proximal convoluted tubules and medullary thick ascending limbs. Urodilatin-stimulated cGMP accumulation was almost equal to that stimulated by the same concentrations of ANP in these nephron segments. Urodilatin (10(-8) M) did not stimulate cGMP accumulation in glomeruli, but it stimulated cGMP accumulation in IMCD by threefold. This pattern was quite similar to that with ANP. It was concluded that urodilatin has a similar ability to ANP in stimulating cGMP synthesis and that the main target sites are glomeruli and IMCD.

Animals↗
PubMed1993

Space microbiology--lethality, mutagenicity and cytological effects of terrestrial microorganisms by irradiation of cosmic proton under simulated space condition.

We have been discussing in connection with a space quarantine. The subject is not merely an academic problem, but it contains a fundamental problem which avoid the contamination of other planets by terrestrial microflora. The space environments in the solar system were simulated by using an apparatus of cryostat (low temperature of 110-310K, high vacuum of 1 x 10(-8) torr) and proton irradiation from the Van de Graaff generator. After exposure to a barrage of protons corresponding to about 250 years in solar space, Tobacco mosaic virus, Bacillus subtilis spore, Staphylococcus aureus. Micrococcusflavus, Clostridium mangenoti spore and Aspergillus niger spore showed considerably high survival rates. Furthermore, it was found firstly that an irradiation of proton induced considerable mutation frequency compared to that of spontaneous and caused also the cytological effects based on a damage of chromosome.

Bacteria↗
PubMed1992

Survival rates of some terrestrial microorganisms under simulated space conditions.

In connection with planetary quarantine, we have been studying the survival rates of nine species of terrestrial microorganisms (viruses, bacteria, yeasts, fungi, etc.) under simulated interstellar conditions. If common terrestrial microorganisms cannot survive in space even for short periods, we can greatly reduce expenditure for sterilizing space probes. The interstellar environment in the solar system has been simulated by low temperature, high vacuum (77 k, 4 x 10(-6) torr), and protons irradiation from a Van de Graaff generator. After exposure to a barrage of protons corresponding to about 250 years of irradiation in solar space, Tobacco mosaic virus, Bacillus subtilis spores, Aspergillus niger spores and Clostridiun mangenoti spores showed survival rates of 82%, 45%, 28%, and 25%, respectively. Furthermore. pathogenic Candida albicans showed 7% survival after irradiation corresponding to about 60 years in space.

Bacteria↗
PubMed1992

Colliding malignant lymphoma and adenocarcinoma of the stomach: case report.

We report a case of malignant lymphoma presenting as the superior vena cava syndrome. This case is very interesting since both adenocarcinoma mucocellulare scirrhosum, Borrman type IV, and lymphoma were present in the stomach, forming colliding neoplasms. Rather than systemically disseminated, the lymphoma cells were localized in the stomach, the intestine, a few perigastric lymph nodes and in a mediastinal mass, which may have constituted a neoplastic thymus invaded by lymphoma cells from the stomach. The unique occurrence of the histological combination as gastric colliding neoplasms is discussed.

Adenocarcinoma↗
PubMed1991

[Computerized tomography immediately after surgery in the neurosurgical operating theater].

A TCT-300 scanner (manufactured by the Toshiba Co., Tokyo) has been installed in the operating room of Shinshu University Hospital since 1986. This neurosurgical operating CT scanner system was developed for obtaining intra- and postoperative CT images in the operating room. We have carried out immediate postoperative CT scanning in 206 cases: 170 were major and 36 were minor operations. A mobile CT scanner gantry has been used in 125 cases since June, 1988. We obtained CT images immediately after surgery on the digitalized operating table, the motion of which can be controlled as with the conventional CT scanner table. Immediate postoperative CT scans showed the extent of removed tumors or hematomas, position of the tip of ventricular or cisternal tubes, injury to the surrounding normal brain caused during the removal of lesions, and postoperative complications such as hemorrhage, brain swelling and surgical patties which had been inadvertently left in the wound. This CT scanner system in the operating room proved to be useful in the postoperative care of neurosurgical patients.

Adult↗
PubMed1991

[A case of disproportionately large communicating fourth ventricle (DLCFV) combined with syringomyelia and Chiari malformation].

We report a rare case of disproportionately large communicating fourth ventricle (DLCFV) combined with syringomyelia and Chiari malformation. The case was a 27-year-old male who underwent ventriculoperitoneal (V-P) shunt on the right side for hydrocephalus caused by traumatic intracerebral and intraventricular hemorrhage. One month later, he became somnolent with posterior fossa symptoms (nausea, vomiting and nystagmus). CT scan demonstrated enlarged fourth ventricle, which was diagnosed as DLCFV because the ventriculogram revealed patency of the aqueduct. One and half month later a second V-P shunt was made on the left side to increase the shunt flow. He became ambulatory with a cane, although the fourth ventricle remained moderately dilated on CT scan. Two months after the additional V-P shunt, he slipped and hit the occiput and immediately became tetraparetic. The patient was treated conservatively under the diagnosis of central spinal cord injury. The MRI taken 2 months after the accident revealed Chiari malformation (type 1), syringomyelia and a dilated fourth ventricle which was compressing the brainstem. After the fourth ventriculoperitoneal (FV-P) shunt, the tetraparesis transiently improved but then again worsened. On the CT scan the syrinx did non change in size, while the size of the fourth ventricle became normal. After syringoperitoneal (S-P) shunt the patient showed a moderate improvement of tetraparesis. Unfortunately he suffered appendicitis complicated with peritonitis and all the shunts were immediately changed to external drainage. However, the patient developed meningitis and became paraplegic. The motor function of the upper extremities slightly improved by aspiration of fluid via the external drainage system from the syrinx.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗