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Biomedical subjects

T Yamaki

Publications and source records attributed to T Yamaki.

At least 109 records · Page 6Linked to original sources
PubMed1989

[Preventive effect of KZ-1026 on acute liver injury induced by CCl4 in rats: histochemical, enzyme-histochemical and ultrastructural studies].

The preventive effect of KZ-1026 on acute liver injury induced by CCl4 in rats was evaluated histochemically, enzyme-histochemically and ultrastructurally. Rats that received 50% CCl4 (2 ml/kg) intraperitoneally were sacrificed at 3, 7 and 24 hr. Remarkable reductions in hepatic glycogen, RNA and G-6-Pase activity were observed in the centrilobular area at 3 hr, and ballooned cells appeared in the mid-zone at 7 hr. At 24 hr, the above histochemical parameters in the hepatocytes of the centrilobular area and mid-zone were extensively reduced, while the number of ballooned cells in the mid-zone was increased. KZ-1026 (200 mg/kg) was given orally at 24 and 4 hr before, simultaneously with or 3 hr after CCl4 treatment, and each rat was sacrificed at 24 hr after CCl4 administration. Pretreatment with KZ-1026 24 hr before CCl4 administration prevented reduction of RNA, glycogen and G-6-Phase activity, as well as disruption of rER and proliferation of sER due to CCL4 toxicity. This preventive effect of KZ-1026 was reduced by posttreatment; however, only the decrease in cytoplasmic RNA was well prevented. These results suggested that KZ-1026 is protective against CCl4-induced acute liver injury.

Acute Disease↗
PubMed1989

Stimulation of rat liver growth by a 1,3-dithiole derivative, KZ-1026.

The oral administration of 2-(1,3-dithiol-2-ylidene)-1-phenyl-1,3-butanedione (KZ-1026) to normal rats at doses of 50, 100 and 200 mg/kg/day for 3 days accelerated liver enlargement in association with a dose-dependent increase in the total amounts of protein, RNA and DNA in the liver. The liver weight at 24 hr after the third dose of 200 mg/kg reached 174% of the control. With respect to the effect on liver enlargement, KZ-1026 differed from phenobarbital, since KZ-1026, unlike phenobarbital, increased hepatic DNA content without significant effects on P-450 and aminopyrine-N-demethylase. Incorporation of [3H]thymidine into liver DNA was stimulated by a single dose of KZ-1026 (200 mg/kg), and it peaked at 24 hr post dose (18 times the control), followed by an increase in the number of liver nuclei. Liver growth was also accompanied by an increasing hepatic reserve cell mass, expressed by the capacity of eliminating exogenous galactose from the blood stream. Pretreatment with KZ-1026 (200 mg/kg/day) for 3 days significantly improved the survival rate of subtotally hepatectomized rats from 39% to 78%. These findings indicate that KZ-1026 accelerates hepatocyte proliferation, resulting in an enhancement of liver functional mass in normal rats.

Animals↗
PubMed1988

Functional analysis of mononuclear cells infiltrating into tumors. III. Soluble factors involved in the regulation of T lymphocyte infiltration into tumors.

We have analyzed the mechanisms controlling the accumulation of T lymphocytes in tumor tissues. Spleen cells, left or right popliteal lymph node cells, and tumor-infiltrating cells were obtained from tumor-inoculated rats and were cultured for 24 h. Culture supernatants were obtained and assessed for lymphocyte migration factor (LMF) activity with the use of a modified Boyden chamber. We found that tumor-infiltrating cells derived from T-9-sensitized rats produced LMF. Two waves of LMF production were observed. The first wave of LMF production was detected between 6 and 12 h (LMF-a) and the second wave of LMF production was detected between 4 and 6 days (LMF-4d and -6d) after tumor inoculation. The tumor-infiltrating cells consisted of heterogenous cell populations. We found that only tumor-infiltrating neutrophils of T-9-sensitized rats produced LMF-a. Five peaks of LMF (A through E) were detected upon fractionation of LMF-a using Mono Q anion exchange column chromatography. Peak D exhibited the strongest activity. The action of peak D was chemotactic, but not chemokinetic. The m.w. of peak D was 33,000 and 70,000. Only W3/25 (+) (helper/inducer) T cells were found to be sensitive to peak D. The production of LMF-a by purified tumor-infiltrating neutrophils in vitro is in agreement with the histologic observation that the infiltration of neutrophils precedes the appearance of W3/25 (+) T cells in tumor tissues of T-9-sensitized rats. It is thus likely that peak D of LMF-a is responsible for the infiltration of T lymphocytes into tumor tissues.

Animals↗
PubMed1988

Extensive spinal necrosis with spinal leptomeningeal dissemination of cerebral astrocytoma. Case report.

A 58-year-old male with malignant astrocytoma in the right parietal lobe developed ascending spinal dysfunction 15 months after subtotal resection of the primary lesion. He was treated by postoperative radiation and combined chemotherapy. Autopsy revealed extensive spinal necrosis affecting the level below the lower cervical region. Microscopic examination demonstrated diffuse leptomeningeal metastasis of glioma cells to the whole spine. There was no previous report in the literature of massive myelomalacia attributable to leptomeningeal dissemination an astrocytic supratentorial tumour. Clinical and neuropathological findings suggested that disturbance of venous drainage of the spinal cord might be responsible for myelomalacia in this case.

Astrocytoma↗
PubMed1988

Immunotherapy of solid tumor by intratumoral infusion of lymphokine-activated killer cells.

Fifty million lymphokine-activated killer (LAK) cells were infused into rat T9 gliosarcoma tumors for 1 hr at an infusion rate of 0.1 ml/hr. Cultured normal spleen cells were infused into similar tumors as a control. The LAK cell-treated tumors began to regress at approximately 3 weeks after infusion and disappeared by 6 weeks, while the cultured normal spleen cell-treated tumors grew progressively. Immunohistochemical analysis demonstrated prominent infiltration of cytotoxic/suppressor T cells in the LAK cell-treated tumors, while few lymphocytes were recognized in the control tumors. These data suggested that LAK cells infused intratumorally might be capable of mediating tumor regression by inducing host immunity against the tumor.

Animals↗
PubMed1988

Diurnal changes in vasopressin and oxytocin levels in cerebrospinal fluid of post-operative patients with intracranial aneurysms.

Diurnal changes in vasopressin and oxytocin levels in cerebrospinal fluid were investigated under normal diurnal conditions. The patients examined had ruptured intracranial aneurysms, and underwent neck-clipping operations and continuous drainage from the basal cistern. All of the patients recovered consciousness without signs of neurological deficit. The investigations were conducted for 2 days starting 5-9 days after the neck-clipping operations were performed. The oxytocin concentration decreased as night fell, remained low during this period and then increased during the day. The vasopressin level demonstrated no definite rhythmic tendency. No correlation was revealed between the changes in the concentrations of either vasopressin or oxytocin in the cerebrospinal fluid and the osmolality.

Adult↗
PubMed1987

Characterization of rat T cell subset antigen by monoclonal antibody.

6B2-B8 T cell hybridoma cells were used to immunize mice, and immune spleen cells were fused with NS/1 myeloma cells. One clone, designated RTH-7, reacted with 89.5% of rat thymocytes, 30.2% of rat spleen cells, and 42.3% of rat lymph node cells. The RTH-7 reacted with a subset of rat T cells but not with B cells. Double staining analysis demonstrated that RTH-7 stained a rat T cell subset distinct from R1-10B5-positive cells that were known to be equivalent to mouse Lyt-2. It was revealed that RTH-7 and W3/25 recognize different antigenic epitopes on the same molecule. The RTH-7 as well as W3/25 substantially inhibited the production of interleukin 2 by cells in mixed lymphocyte reaction and the lymphocyte proliferation induced by mixed lymphocyte reaction. The RTH-7 inhibited the lymphocyte proliferation induced by Con A whereas W3/25 failed to do so. The RTH-7 defined antigen has a molecular weight of 53,000 under reducing condition and 47,000 under nonreducing condition. The RTH-7 defined antigen showed a wide range of heterogeneity in pI (6.2-8.8). The associated molecule of approximate molecular weight of 27,000 was occasionally detected with the RTH-7 defined antigen in 6B2-B8 T cell hybridoma cells as well as peripheral T cells but not in thymocytes. Thus, RTH-7 detects a cell surface antigen of a functional T cell subset of rat origin.

Animals↗
PubMed1987

[Traumatic posterior fossa hematoma].

The traumatic posterior fossa hematoma was regarded as relatively rare thing, but recently, as the result of the prevalence of CT scanners, the number of reported cases is increasing. We report nine cases of traumatic posterior fossa hematoma. We divided into two categories: one was the acute epidural hematoma, the other was the acute subdural hematoma with cerebellar contusion. Five were cases of the acute epidural hematoma, three were cases of the acute subdural hematoma with cerebellar contusion and a case had both an epidural and a subdural hematoma. All the cases had struck the occipital region and had the occipital bone fracture. The prognosis of the five cases of the acute epidural hematoma was excellent, but that of the four cases of the acute subdural hematoma with cerebellar contusion was poor and they all died inspite of the removal of the hematoma executed in three cases. We estimated that the hitting forth was extremely strong in cases of the subdural hematoma with cerebellar contusion, and that the momentary deformity of the occipital bone might injure the cerebellum directly. Once a hematoma was produced in the posterior fossa, it oppresses the brainstem and causes the acute hydrocephalus, so the state of consciousness and respiration deteriorate suddenly. In cases of the acute epidural hematoma, appropriate surgical intervention could save the patients and resulted in good outcome. But in some cases of the fulminant type acute epidural hematoma of the posterior fossa caused by tearing the sinuses, though we have not experienced, patients die before the diagnosis and treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1987

[A case of persistent trigeminal artery aneurysm treated by proximal obliteration of feeding vessels in both intra- and extracranial compartments].

The authors described a case with a saccular aneurysm of the persistent trigeminal artery (PTA) treated with intra- and extracranial proximal obliteration of the feeding arteries. PTA aneurysm is a rare disorder found only 14 cases in the literature. There have been only 4 cases treated by surgical procedure; 2 underwent direct surgery and the remaining 2 had carotid ligation. Both of the cases treated by direct obliteration of the aneurysm sustained diplopia and sensory disturbance around the orbit as postoperative neurological deficits. We thought another choice of treatment to reduce the risk of rupture of the aneurysm avoiding postoperative complications. Clinical presentation of the present case was rt-oculomotor palsy, which disappeared before the operation. Cerebral angiography disclosed an intracavernous sinus aneurysm with a broad neck arising from the rt-internal carotid-PTA junction. Bilateral posterior cerebral arteries were perfused by the rt-internal carotid artery was compressed manually, lt-vertebral angiography showed the aneurysm and the internal carotid artery simultaneously via the PTA as retrograde filling. Because the direct surgery might cause damage to the cranial nerves passing through the cavernous sinus, we employed proximal obliteration of the feeding vessels. The operation was done by the following steps: ligation of the cervical portion of the rt-internal carotid artery, rt-superficial temporal artery-middle cerebral artery anastomosis, clipping of the PTA at the basilar side.(ABSTRACT TRUNCATED AT 250 WORDS)

Cavernous Sinus↗
PubMed1986

Construction of rat-mouse T cell hybridomas that express regulatable rat interleukin 2 receptor.

Spleen cells obtained from Lewis rats were cultured with 4 micrograms/ml Con A for 96 hr, and activated cells were fused with BW5147 mouse T lymphoma cells. Seven clones obtained by fusion expressed rat IL 2R. The expression of rat IL 2R on those hybrid cells could be up-regulated by IL 2 itself, ATL-derived factor, and TPA and CA++ ionophore. Those IL 2R could be down-regulated by murine MoAb ART-18 that detects rat IL 2R. All hybrid clones produced IL 2 constitutively. IL 2 produced by hybrid cells bound to its receptor and promoted the proliferation of hybrid cells in some clones. Incubation of cells with exogenous IL 2 resulted in the proliferation of hybrid cells, whereas the proliferation of some clones was inhibited by exogenous IL 2, indicating that IL 2 had bifunctional properties on cell growth. Rat IL 2R from 6H2-F9 hybrid cells was studied by both one- and two-dimensional SDS-PAGE with ART-18. The IL 2R derived from 6H2-F9 cells had 72,000 to 77,000 and 40,000 to 48,000 m.w. major components under nonreducing conditions, and had 50,000 to 56,000 m.w. major and 35,000 to 38,000 m.w. minor components under reducing conditions. The 110,000 m.w. component, the third component of IL 2R, was constantly observed in 6H2-F9 hybrid cells.

Animals↗
PubMed1986

[A simple bioassay method of urinary indoleacetic acid, a cancer growth factor].

Indoleacetic acid (IAA) is produced in cancer tissue and promotes the growth of cancer cells and of the surrounding cells which become cancerous. It was shown that the urine of cancer patients contains larger amounts of IAA than that of healthy persons (except diabetics). This increased IAA level may be derived from the cancer tissue. The measurement of urinary IAA can thus be used to screen cancer patients. Various assay methods for IAA were tested, but 15 min. are required even with the modified HPLC used in this laboratory directly with unpurified urine. Hence it is unsuitable for measuring large numbers of samples within short period. The present work reports on a simple, easy and rapid method for determining urinary IAA in large numbers of samples by using Avena coleoptile sections. Ten sections are floated for 3 hr. on 1/50 diluted urine with 0.5 ppm gibberellic acid (GA). Up to a certain limit their elongation is proportional to the IAA concentration in the diluted urine. Persons whose urine causes coleptile section to elongate more than 1.3 mm require detailed clinical examination to determine whether or not they suffer from cancer.

Biological Assay↗
PubMed1986

Rapidly growing aneurysm.

A rare case of rapidly growing intracranial aneurysm is reported. The enlarged aneurysmal wall was extirpated and studied histologically. The cause of the rapid growth of the aneurysm is discussed.

Humans↗
PubMed1986

Value of high-resolution computed tomography in diagnosis of petrous bone fracture.

High-resolution computed tomography (CT) was performed on 31 patients clinically suspected of having petrous bone fracture. The location of the fracture was demonstrated accurately in 28 patients (90.3%), whereas it could be diagnosed by plain skull film in only 17 patients (54.8%). The anatomic location of fractures demonstrated by high-resolution CT clearly corresponded to the clinical symptoms and signs. We have classified petrous bone fracture into five types according to the anatomic levels demonstrated on CT images. The findings indicate that high-resolution CT is extremely useful for diagnosing petrous bone fracture.

Humans↗
PubMed1986

Immunobiological and biochemical characterization of solubilized rat gliosarcoma cell tumor-associated transplantation antigens.

Tumor-associated transplantation antigen (TATA) was solubilized with n-butanol from rat gliosarcoma cells (T-9). Under the conditions used for the solubilization of TATA, the viability of T-9 cells was maintained above 85%, suggesting that the contamination of TATA with cytoplasmic protein is minimal. Normal Fischer rats were treated with 500 micrograms of n-butanol extract and inoculated with 2 X 10(6) viable T-9 cells. At 8 weeks after the inoculation of viable tumor cells, the tumor diameter was significantly smaller than that in control untreated rats. Rats treated with 770 micrograms of n-butanol extract from T-9 cells were inoculated with 1 X 10(7) syngeneic FTL-13 thymic lymphoma cells or T-9 cells. The rats rejected the T-9 cells, whereas the FTL-13 cells grew gradually until the host died, indicating that the n-butanol extract from T-9 cells contained T-9 cell-specific TATA. The n-butanol extract was characterized by chromatographic separation on a TSK gel G3000SW gel filtration column and a Mono Q anion exchange column with the fast protein liquid chromatography system (FPLC). The TATA of T-9 cells was found to have a molecular weight of approximately 40,000-70,000 and was eluted at 0.6-0.9M NaCl from the Mono Q column. The cellular mechanisms responsible for the rejection of T-9 cells in the rats treated with the n-butanol extract were also examined. Adoptive transfer and in vitro experiments demonstrated that helper T cells for the generation of cytotoxic T lymphocytes were generated in the rats treated with n-butanol extract.

Animals↗
PubMed1986

[Hematomas of the lenticular nucleus and pons in a hypertensive patient].

Secondary pontine hemorrhages are not rare in intracranial hypertension caused by a supratentorial mass lesion. Cerebral herniation and caudal dislocation of the brainstem account for the secondary pontine hemorrhages. In the present case, two unrelated hemorrhages were demonstrated by an early CT. Neurological findings and CT thus suggest that this is a rare case in which supratentorial and infratentorial hypertensive intracerebral hemorrhages occurred simultaneously.

Adult↗
PubMed1985

Acute brain edema in fatal head injury: analysis by dynamic CT scanning.

Dynamic computerized tomography (CT) was performed on 42 patients with acute head injury to evaluate the hemodynamics and to elucidate the nature of fatal diffuse brain bulk enlargement. Patients were divided into two groups according to the outcome: Group A included 17 nonfatally injured patients, eight with acute epidural hematomas and nine with acute subdural hematomas; Group B included 25 fatally injured patients, 16 with acute subdural hematomas and nine with bilateral brain bulk enlargement. Remarkable brain bulk enlargement could be seen in all fatally injured patients with acute subdural hematoma. In 29 (69%) of 42 patients, dynamic CT was performed within 2 hours after the impact. In the nonfatally injured patients with brain bulk enlargement, dynamic CT scans suggested a hyperemic state. On the other hand, in 17 (68%) of the 25 fatally injured patients, dynamic CT scans revealed a severely ischemic state. In the fatally injured patients with acute subdural hematoma, CT Hounsfield numbers in the enlarged hemisphere (hematoma side) were significantly lower than those of the opposite side (p less than 0.001). Severe diffuse brain damage confirmed by follow-up CT scans and uncontrollable high intracranial pressure were noted in the fatally injured patients. Brain bulk enlargement following head injury originates from acute brain edema and an increase of cerebral blood volume. In cases of fatal head injury, acute brain edema is the more common cause of brain bulk enlargement and occurs more rapidly than is usually thought.

Acute Disease↗
PubMed1985

A soluble factor distinct from interleukin 2 is involved in the generation and differentiation of cytotoxic T cells.

The involvement of cytotoxic cell-generating factor (CGF) in the generation of cytotoxic cells against syngeneic tumor (T-9) cells and in the rejection of the tumor cells has been investigated. It was found that Con A-sup (culture supernatant of concanavalin A-stimulated rat spleen cells) contained CGF, which was distinct from interleukin (IL) 2 and interferon. It should be noted that spleen cells produced CGF upon inoculation of syngeneic tumor cells into tumor-sensitized rats. Production of CGF preceded the appearance of cytotoxic cells against inoculated tumor cells. In these rats, the inoculated tumor was rejected. In contrast, spleen cells failed to produce CGF upon inoculation of tumor cells into normal rats; in these rats, cytotoxic cells were not detected and the inoculated tumor grew. These data suggested that CGF was produced as an in vivo response of the host immune system and was involved in the generation of cytotoxic T cells. CGF obtained from sensitized spleen cells was chromatographically separated from IL 1, IL 2, and colony-stimulating factor, and the chromatographically separated CGF did not contain IL 3 activity.

Animals↗