Biomedical subjects

T Hotta

Publications and source records attributed to T Hotta.

At least 181 records · Page 10Linked to original sources

PubMed1994

[A case of hemangioblastoma in the thalamus].

Supratentorial hemangioblastoma is encountered very rarely. About 80 cases in all have been reported. The authors present a case of supratentorial hemangioblastoma in the thalamus with gradually enlarging cysts. The patient was a 45-year-old man with complaints of left hemiparesis and headache. Computed tomographic scans of the brain showed a cystic mass with mural nodule in the right thalamus. Left vertebral angiography demonstrated a vascular tumor fed by a thalamogeniculate artery. A right temporo-parietal craniotomy was performed and the tumor was totally resected through the transcortical approach. The histological diagnosis was hemangioblastoma. Post-operative course was good except for a minor complication of the left lower quadrant homonymous hemianopsia and left hemiparesis which had disappeared at the time of discharge.

Hemangioblastoma↗

PubMed1994

Recovery of polyclonal hematopoiesis in patients with myelodysplastic syndromes following successful chemotherapy.

We performed X-linked restriction fragment length polymorphism (RFLP)-methylation analysis to study the clonality of hematopoiesis in five patients with myelodysplastic syndromes (MDS), who had responded to chemotherapy. Two patients had MDS in blast crisis, two had refractory anemia with an excess of blasts in transformation (RAEB-T), and one had acute myelogenous leukemia with trilineage myelodysplasia (AML-TMDS). Following the administration of low-dose cytarabine therapy or of conventional intensive chemotherapy, we observed a reversion to polyclonal hematopoiesis in three patients who achieved a complete remission (CR). Polyclonal hematopoiesis persisted in one patient in CR, and monoclonal hematopoiesis persisted in another patient of minor response. These results indicate that polyclonal hematopoiesis can be restored in some MDS patients who achieved CR. We are encouraged, therefore, to administer intensive consolidation chemotherapy to prolong the duration of remission.

Adult↗

PubMed1994

[Two cases of traumatic intracerebral pneumocephalus].

Two cases of traumatic intracerebral pneumocephalus, a rare complication of head trauma, are presented. Case 1: A 14-year-old boy had a strong concussion in his forehead due to a motorbike accident. Slightly obtunded on admission showing GCS 10, he became conscious in several days. Head CT performed after 17 days showed a round air image in the right frontal lobe which kept increasing in size thereafter. Bilateral frontal craniotomy was performed 31 days after the injury. A craniodural defect with a herniated brain was found in the superior wall of the posterior ethmoid sinus and repaired. Case 2: A 55-year-old man received a left forehead concussion when his motorbike ran into a car from behind. Although he had been conscious ever since admission, head CT after 15 days showed a round air image in the left frontal lobe. MRI demonstrated the air to be located in the cerebral parenchyma distinctly and the brain to have herniated into the frontal sinus. As the air showed a tendency to increase in volume and mild psychic and memory disturbances appeared, bilateral frontal craniotomy was performed 34 days after the injury. A craniodural defect with a herniated brain was detected in the posterior wall of the frontal sinus and repaired. These two patients showed a small amount of cerebrospinal fluid (CSF) rhinorrhea before the operation. Following the surgical repair, no recurrence of pneumocephalus and CSF rhinorrhea has been seen in either case. Intracerebral pneumocephalus secondary to closed head trauma was thought to have been due to herniation of contused brain into a craniodural defect.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1994

[A case of brain abscess of the basal ganglia which resulted in disastrous outcome due to ventricular ruptures].

A case of deep-seated brain abscess that ruptured twice into the ventricle and resulted in death is presented. A 45-year-old man had experienced pyrexia and headache for 3 days before admission. On admission he was somnolent (GCS: 13) but there were no abnormal neurological findings except nuchal rigidity and Kernig's sign. Computed tomography (CT) scan showed a ring enhanced mass near the left caudate head and dilated ventricles. In comparison with CT performed at the former hospital it was diagnosed that a rupture into the ventricle of the brain abscess had occurred. Ventricular drainage was performed at once and white purulent cerebrospinal fluid was obtained. Thereafter, he was treated with some antibiotics and his conditions seemed to stabilize for a while. Serial CT images demonstrated that the size of the abscess seemed to be enlarging. Just when we planned to undertake stereotactic aspiration, the second ventricular rupture occurred and he died. According to this case, it is suggested that once a deep-seated brain abscess near the ventricular system is suspected, it should be aspirated by means of CT-guided stereotactic surgery immediately.

Basal Ganglia Diseases↗

PubMed1993

Expression of carcinoembryonic antigen in fresh human gastric cancer cells assessed by flow cytometry.

The expression of carcinoembryonic antigen (CEA) by tumor cells from freshly excised human gastric cancers was investigated using flow cytometry (FCM). Highly purified fresh human cancer cells were obtained from solid tumors in 20 patients and from malignant ascites in 6 patients. Thirteen of the 26 tumors were positive for CEA by FCM. CEA expression was more common in well-differentiated tumors than in poorly differentiated tumors. CEA expression was investigated by both FCM and immunohistochemistry in 9 patients, and the two methods agreed in 8 of them. However, quantitative evaluation of CEA expression could only be performed by FCM and not by immunohistochemical staining. FCM could analyze the expression of CEA not only on the cell membrane but also in the cytoplasm, by using gastric cancer cells with or without Triton X-100 treatment. Thus, this study showed that CEA expression can be determined and evaluated quantitatively by FCM.

Aged↗

PubMed1993

The close relationship between DNA replication and the selection of differentiation lineages of human erythroleukemia cell lines K562, HEL, and TF1 into either erythroid or megakaryocytic lineages.

The selection of differentiation lineages into either erythroid or megakaryocytic series was analyzed with human erythroleukemia cell lines K562, HEL, and cytokine-dependent TF1. A tumor promoter, TPA, induced a megakaryocyte marker, glycoprotein IIb/IIIa (GP IIb/IIIa) or IIIa (GP IIIa), but suppressed erythroid differentiation. On the other hand, aphidicolin, which is a potent inhibitor of DNA replication, inhibited GP IIb/IIIa or IIIa expression, but induced the expression of erythroid phenotypes. These phenomena were observed in all erythroleukemia cell lines tested. The bromodeoxyuridine labeling experiments indicated that de novo DNA synthesis was completely suppressed by aphidicolin treatment but was well preserved in TPA-treated cells. Among these three cell lines, erythropoietin (EPO) treatment induced erythroid differentiation of TF1 cells, which was dependent on GM-CSF or IL-3. In this case, EPO functioned as the survival factor and mild stimulator for cell proliferation as well as the inducer of erythroid differentiation. However, when either GM-CSF or IL-3 was depleted from the culture medium, TF1 ceased cell growth; concomitantly, hemoglobin-positive cells appeared, which is consistent with the results obtained with aphidicolin. The incubation of K562 cells for 48 h with either TPA or aphidicolin induced the irreversible commitment of cells to megakaryocytic and erythroid lineages, respectively. Our results using three different erythroleukemia cell lines suggest that a possible linkage between the DNA replication system and the selection of a differentiation lineage is the common feature of human erythroleukemia cell lines, and that these culture systems provide a suitable model for the analysis of the signal transduction system for differentiation lineage selection.

Aphidicolin↗

PubMed1993

Interrelationship between O6-alkylguanine-DNA alkyltransferase activity and susceptibility to chloroethylnitrosoureas in several glioma cell lines.

In order to study the dynamic relationship in glioma cells between O6-alkylguanine-DNA alkyltransferase (AGT) activity and resistance to the cytotoxic effect of chloroethylnitrosoureas (CENUs), we investigated the changes in sensitivity to 1-(4-amino-2-methyl-5-pyrimidinyl)methyl-3-(2-chloroethyl)-3-nitrosourea hydrochloride (ACNU) after modulation of AGT activity. In ACNU-resistant rat glioma cell lines (9LR1, 9LR3, and 9LR12) and a human glioma cell (HNG-1), O6-methylguanine enhanced cytotoxicity to ACNU following a depletion of AGT activity. But no enhancement of cytotoxicity was seen in an ACNU-sensitive rat glioma cell line (9L). In the 9L and 9LR12 cells, equivalently sublethal doses of ACNU similarly depleted AGT activity but the regeneration rates of this repair protein were different. In the case of a 7-day pretreatment with human recombinant interferon-beta (HuIFN-beta), although it could modulate AGT activity in HNG-1 cells, no definite influence on cellular sensitivity to CENUs was observed. However, a 50-day pretreatment with HuIFN-beta conferred resistance to CENUs on them despite its effect to reduce AGT activity. Thus, diversity was seen in the relation between AGT activity and resistance to CENUs when AGT activity was modulated by HuIFN-beta. The results of this study suggest that AGT activity is one of factors affecting cellular sensitivity to CENUs but that alternative mechanisms of tolerance may be induced depending upon some environmental effects.

Animals↗

PubMed1993

Differential production of interleukin 6 in human osteosarcoma cells and the possible effects on neoplastic bone metabolism.

Interleukin 6 (IL-6) exerts well-established effects on cells of the immune system as well as on various other cell types. We have investigated the effects of IL-6 produced by human osteosarcoma cells on tumor cells from two clonal human osteosarcoma cell lines, KSU.C3 and NOS-1.C8. We were unable to identify any effects of IL-6 such as cell proliferation, alkaline phosphatase activity, osteocalcin production, or collagen synthesis on the bone-forming phenotypes. However, the KSU.C3 cell line, which showed a little osteoid and no bone formation and was accompanied by a few osteoclasts in the xenografted tumors, produced high levels of IL-6, the production of which was quickly and easily stimulated by various agents. On the other hand, the NOS-1.C8 cell line, which formed abundant osteoid or bone and was accompanied by no osteoclasts in the xenografted tumors, produced no detectable levels of IL-6 without stimulation, and the production of IL-6 in response to IL-1 beta was slower. Our data suggest that IL-6 produced by osteosarcoma cells does not play an important role in bone formation, but may mediate osteoclastic bone resorption.

Alkaline Phosphatase↗

PubMed1993

Spontaneous rupture of craniopharyngioma cysts. A report of five cases and review of the literature.

Reports of spontaneous rupture of a craniopharyngioma cyst are extremely rare. Five cases of spontaneous rupture of a craniopharyngioma cysts are reported. Clinical symptoms included chemical meningitis in three patients, alleviation of headache in one, and improvement in a visual disturbance in one. Reduction in cyst size was confirmed by computed tomography or magnetic resonance imaging in three of five patients, and the histopathological diagnosis was confirmed histologically in four patients. Cerebrospinal fluid findings were abnormal in the three patients with chemical meningitis. Spontaneous rupture of craniopharyngioma cysts tended to occur more frequently in adult males. Computed tomography and magnetic resonance imaging were useful in diagnosing cyst rupture, and cerebrospinal fluid findings, especially the presence of cholesterol crystals and an elevated cholesterol concentration, are suggestive, even when no reduction in cyst size is observed radiologically.

Adolescent↗

PubMed1993

Novel interleukin-2 dependent T-cell line derived from adult T-cell leukemia not associated with human T-cell leukemia virus type I.

A novel interleukin-2 (IL-2)-dependent T-cell line, WHN2, was established from a patient with adult T-cell leukemia (ATL) not associated with human T-cell leukemia virus type I (HTLV-I). Neither the original leukemic cells nor the WHN2 cells showed proviral integration in their cellular DNAs by Southern blot analysis. The surface phenotype showed that both the original leukemic cells and the WHN2 cells had a common phenotype of ATL, i.e., positive for CD2, CD4, human leukocyte antigen DR (HLA-DR) and CD25, but negative for CD8, a characteristic of helper/inducer T-cells. Most of the chromosomal abnormalities of the original leukemic cells were maintained in the WHN2 cell line. Furthermore, Southern blot analysis of the T-cell receptor beta-chain gene rearrangement revealed that the original leukemic cells and WHN2 cell line had identical patterns, suggesting that the WHN2 cell line was truly derived from the original leukemic cells. Dose-dependent growth on IL-2 was demonstrated, and at the maximal stimulation, the number of cells doubled within three days. This IL-2-dependent growth was inhibited by the simultaneous existence of anti-IL-2 receptor alpha and beta chain antibodies. These results indicate that the character of the WHN2 cell line is similar to that of the cell lines derived from ATL associated with HTLV-I. Thus, the HTLV-I-negative ATL cell line, WHN2, should be useful in the comparative study of the pathogenesis of ATL associated with or without HTLV-I.

Aged↗

PubMed1993

Neuroblastoma growth factors derived from neurofibroma (NF1): participation of uridine in a neuroblastoma growth.

Human glioma cell extracts were found to elicit a marked growth-promoting activity on human neuroblastoma cells. This activity was also detected in the extracts of neurofibroma type 1 (NF1; von Recklinghausen neurofibromatosis) comprising aberrant Schwann cell growth. The purified substance from the NF1 extracts by HPLC on ODS columns was identical to a pyrimidine nucleoside, uridine, the chemical structure of which was identified by gas chromatography-mass spectrometry. The authentic uridine showed a strong growth-promoting activity on human neuroblastoma cells. Other purine or pyrimidine nucleotides, their derivatives, and ribose sources for their syntheses were employed to test the activity; a purine nucleoside, adenosine, showed a stronger activity than uridine. The current study raises the possibility that human neuroblastoma cells may be affected by dysfunctions of the de novo pathway of both purine and pyrimidine nucleotide biosyntheses.

Cell Division↗

PubMed1993

Growth-promoting action of adenosine-containing dinucleotide on neuroblastoma cells: detection of adenosine-cytidine dinucleotide (ApCp) in neurofibroma (NF1) extracts.

Neurofibroma type 1 tissue was investigated for the presence of growth-promoting activity on human neuroblastoma cells. The activity was isolated by gel filtration and reversed-phase column chromatographs from neurofibroma type 1 extracts. An adenosine-containing dinucleotide (adenylyl(3'-5')cytidine-3'-phosphate) was identified as one of the major components of the activities by its enzymatic fragmentation and liquid chromatography/mass spectrometry. Synthetic adenosine-containing dinucleotide derivatives such as cytidyl(3'-5')adenosine, cytidyl(2'-5')adenosine, adenylyl(3'-5')cytidine, and adenylyl(2'-5')cytidine showed a similar action. Cytidyl(3'-5')adenosine, cytidyl(2'-5')adenosine, and adenylyl(2'-5')cytidine, which are able to release a free adenosine through enzymatic hydrolysis, in particular elicited a strong activity corresponding to that of adenosine with the highest action. These results suggest that neuroblastoma cells are able to use adenosine-containing dinucleotides as well as mononucleotides for their survival and proliferation.

Adenosine↗

PubMed1993

Analysis and distribution of etoposide in rat brain tumor model: intracarotid versus intracarotid with angiotensin II-induced hypertension.

The brain tissue distribution of etoposide has been investigated in 9L gliosarcoma-bearing rats with or without hypertension induced by angiotensin II (AT II). The rat brain tumor models were divided into the following two groups according to etoposide administration route: intracarotid injection (IC) group and intracarotid injection with hypertension induced by AT II (IHIC) group. Ten mg/kg of etoposide was given, and 30 min and 2, 4, 8, and 24 hr later the rats were sacrificed. The drug concentrations in the serum, tumor, and normal brain tissue were analyzed by high-pressure liquid chromatography. The etoposide concentration in the serum, tumor, and normal brain tissue peaked at 30 min in both groups. The serum concentration was similar between the two groups. The etoposide concentration in the tumor was at least 2.2 times higher in the IHIC group than in the IC group at 30 min and 2 hr. The area under drug concentration curve (AUC) in the tumor in the IHIC group was about 2.2 times higher than that in the IC group. The etoposide concentration in the normal brain on the drug injection side changed only slightly from 0.5 hr to 4 hr and was about 3 times higher in the IHIC group than in the IC group. The etoposide concentration in the contralateral normal brain was very low in both groups at 30 min and disappeared thereafter. Intracarotid injection of anticancer drugs with AT II-induced hypertension further increases the drug concentration and AUC in the tumor compared with intracarotid injection alone and can be useful in treatment of malignant brain tumors.

Angiotensin II↗

PubMed1993

Mutations of the p53 gene in B-cell lymphoma.

Mutations of p53 gene have been recognized to be the most common genetic changes in human cancers. Recently, p53 gene mutations have been found in some patients with common subtypes of B-cell lymphoma (9/48:18.8%), Burkitt lymphoma (9/27:33.3%) and chronic lymphocytic leukemia (6/40:15%). Evidences to suggest that p53 gene mutations are associated with the disease progression in B-cell lymphoma have emerged. Functions of wild-type p53 and its mutant's probable role in B-cell lymphomagenesis are described in this review.

Genes, p53↗

PubMed1993

Induction of neutrophil alkaline phosphatase gene expression by granulocyte colony-stimulating factor in chronic myelogenous leukemia.

The mechanism underlying defective neutrophil alkaline phosphatase (NAP) activity in chronic myelogenous leukemia (CML) was examined using Northern blotting analysis and NAP staining. Fourteen patients with Ph1-positive CML in the chronic phase were included in this study. Polymorphonuclear cells (PMN), containing more than 80% of stab and segmented neutrophils, were collected from peripheral blood (PB) by methylcellulose sedimentation after density gradient centrifugation. Neutrophil alkaline phosphatase mRNA (NAPmRNA) expression was very weak in all patients. When incubated with granulocyte colony-stimulating factor (G-CSF) for 24 h, the PMN of all patients expressed a detectable level of NAPmRNA. NAP score, which semiquantitatively reflects the activity of gene products, was also elevated after incubation with G-CSF in 12 patients. However, a higher dose of G-CSF was required for the maximum response than was the case for normal bone marrow PMN, which also manifested increases of NAPmRNA and its products on stimulation by G-CSF. The present study suggests that the PMN of CML express NAPmRNA and produce its products in response to G-CSF, but that they are less sensitive to G-CSF than normal bone marrow PMN.

Adolescent↗

PubMed1993

An autoreactive T cell clone generated in the autologous mixed lymphocyte reaction in a patient with gastric carcinoma.

Autoreactive T cell clones were established from a patient with early gastric carcinoma and a healthy control in order to investigate the mechanism of suppression of autologous mixed lymphocyte reaction (AMLR) and its significance in immune surveillance against tumor. Clone 3F6 from the gastric carcinoma patient responded to only autologous non-T cells with less reactivity than 4 clones from the control subject. The proliferative response of clone 3F6 to interleukin-2 and immobilized anti-CD3 antibody was also suppressed when compared with the control clones. Autoreactive T cells were able to kill tumor cells and autologous PHA-blasts. The cytotoxic activity of clone 3F6 was also markedly suppressed when compared with the control clones. This data suggests that autoreactive T cells may be impaired in cancer patients and that this immunological disorder might cause the defective immune surveillance against tumors.

Autoimmunity↗

PubMed1993

Cerebral metabolism and function during normothermic retrograde cerebral perfusion.

Retrograde cerebral perfusion through a superior vena cava (SVC) cannula is a new technique used to protect the brain during circulatory arrest. Cerebral blood flow, oxygen consumption, blood sugar consumption and auditory brain stem responses were measured at various rates (100, 200 and 300 ml min-1) of retrograde cerebral perfusion in normothermic mongrel dogs (n = 12, body-weight 13-15 kg). During perfusion about 20% of the perfusate from the SVC was returned via the aorta, while the rest drained into the inferior vena cava. External jugular venous pressure increased as the perfusion rate increased (mean(s.d.) 26.0(6.4) mmHg at a rate of perfusion of 300 ml min-1). Oxygen and blood sugar consumption also increased as the rate of perfusion increased. Retrograde cerebral perfusion at 300 ml min-1 provided half of the cerebral blood flow (mean(s.d.) 14.7(6.4) versus 34.3(7.8)ml min-1) of antegrade cardiopulmonary bypass (CPB). Analysis of the blood returned through the aorta during perfusion at a rate of 300 ml min-1 showed that mean(s.d.) oxygen consumption was about one-third (4.4(2.1) versus 12.3(7.1) ml min-1) and blood sugar consumption about 15% (17(22) versus 114(54)mg min-1) of that seen in blood returned through the SVC during CPB. Auditory brain stem responses disappeared immediately when perfusion was started but recovered completely as soon as CPB was resumed. Although the oxygen provided by perfusion was not sufficient to maintain cerebral function, it should help protect the brain during circulatory arrest.

Animals↗

PubMed1993

Clinical and cytogenetic findings of myelodysplastic syndromes showing hypocellular bone marrow or minimal dysplasia, in comparison with typical myelodysplastic syndromes.

Hematologic and cytogenetic data were collected on 401 myelodysplastic syndromes (MDS) patients in Japan and their clinical relevance was analyzed. More than 50% of the MDS patients with hypocellular bone marrow had > 5% marrow blasts at the time of MDS diagnosis and frequently had complex aberrations (chromosome changes at three or more regions). They showed peripheral blood findings resembling those of aplastic anemia, but progression into leukemic phase and the prognosis tended to mimic typical MDS. In MDS patients with minimal dysplasia, hematologic parameters were different from those of aplastic anemia. However, the low incidence of leukemic transformation and the favorable prognosis was similar to that of aplastic anemia. More than 90% of the patients in this group had refractory anemia and had normal karyotypes. Thus differential diagnosis from a low grade aplastic anemia is important, since this type of MDS might have a clonal nature as well. In conclusion, although some hematologic and clinical deviations are noticed in MDS with hypocellular marrow or minimal dysplasia, these MDS subtypes might constitute marginal forms of MDS.

Adult↗