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T Hatayama

Publications and source records attributed to T Hatayama.

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

[Failure to preserve hearing in acoustic neuroma surgery: experiences after introduction of MRI].

This report elucidates our experiences on acoustic neuroma surgery, in which auditory function was lost postoperatively, although conservation of hearing had been intended preoperatively. Five ears from four patients (two ears: unilateral, three ears from bilateral acoustic neuromas) were operated on via standard retromastoid route, with monitoring of auditory evoked potentials. Abolition of ABR occurred when surgical manipulations were performed within the internal auditory canal. Pulling tumor tissue away from the cochlea toward the brain stem has proved to be a hazardous procedure. Recognizing the condition of tumor tissue within the internal auditory canal is prerequisite for hearing preservation. For this purpose, MRI is very useful because tumor tissue within the internal auditory canal can be clearly visualized. The preoperative criteria in selecting candidates for hearing preservation operations should be more strict because most acoustic neuromas with a diameter of more than 10mm cannot be resected without causing loss of hearing, and, even in such small tumors, the cochlear nerves are infiltrated by tumor cells. Most ABR changes during operations seem to be explicable from avulsion of the cochlear nerve fibers and/or the internal auditory artery from the fundus of the internal auditory canal-the tractus spiralis foraminosus. Postoperative recordings of ABR indicated that progression of degeneration of the cochlear nerve fibers occurred after surgery. This phenomenon may explain postoperative delayed hearing loss observed clinically.

Adolescent↗
PubMed1989

A study of the treatment of multiple aneurysms.

During the period from January 1975 to December 1988, a total of 28 among 215 cases or 13.0% with multiple aneurysms were seen in the Department of Neurosurgery, Hiroshima University. Classifying by sex, there were 17 males and 11 females with a mean age of 52 years. The number of aneurysms was four in 2 cases, three in 6 cases, and two in 20 cases. By location, there were 13 aneurysms in the anterior communicating artery, 20 in the internal carotid artery, 28 in the middle cerebral artery, 4 in the anterior cerebral artery, and 1 in the posterior inferior cerebellar artery. The incidence of rupture of anterior communicating aneurysm was extremely high being 10 out of 11 cases (90%) followed by that of 3 out of 4 cases (75%) for the anterior cerebral aneurysm. Although the number of cases undergoing surgery during the acute stage has been increasing, there was an unexpectedly long waiting period from onset of the initial symptom to surgery averaging 23.6 days. As a rule, clipping was undertaken for the treatment of ruptured aneurysm. For non-ruptured minor aneurysm, coating and wrapping were sometimes performed to reinforce the aneurysmal wall. All the aneurysms were treated through a single craniotomy simultaneously in 13 cases, by two craniotomies in one day in 10 cases, and by two craniotomies on separate days in 5 cases. The results of surgical treatments were satisfactory in all the cases except for a female who expired following surgery due to vasospasm and GI bleeding.

Adult↗
PubMed1988

Whole body hyperthermia of rats decreases insulin binding to erythrocytes.

125I-insulin binding to rat erythrocytes was studied to investigate the effect of whole body hyperthermia on the insulin receptor. Heat treatment of rats at 42 degrees C for 15 min caused a significant decrease (48.7% of control) in 125I-insulin binding to rat erythrocytes. Scatchard analysis showed that the decreased binding resulted from a decrease in the number of the insulin receptors rather than from a decrease in receptor affinity. The decreased receptor number for insulin showed no evidence of recovery, 2 h and 8 h after the hyperthermia. Plasma insulin levels remained lower than the control, up to 8 h after the hyperthermia, whereas plasma glucose, which decreased immediately after the hyperthermia, increased higher than the control, 8 h after the hyperthermia. The low plasma insulin level and decreased number of insulin receptor are believed to be possible factors for the elevation of plasma glucose.

Animals↗
PubMed1988

Characterization of a 42 degrees C-specific heat shock protein of mammalian cells.

HeLa cells synthesize a particular heat shock protein that is induced only by heat shock at 42 degrees C, and not at 45 degrees C or by other stresses that induce major heat shock proteins (Hatayama et al. (1986) Biochem. Biophys. Res. Commun. 137, 957-963). We further characterized the 42 degrees C-specific protein. This protein was induced in mouse FM 3A cells as well as in human HeLa cells. In both cell lines, the protein was resolved into two spots, a basic polypeptide and an acidc one. The mRNA of the protein was induced during the incubation of these cells at 42 degrees C, and the in vitro translation product of mRNA corresponded to the basic, not to the acidic, polypeptide. During the chase period for cells that were labeled with [35S]-methionine, the basic polypeptide of the protein decreased, and the acidic one increased, indicating that the protein was synthesized as the basic polypeptide and then somehow modified to become the acidic one. The 42 degrees C-specific protein was found only in the cytosol fraction, and not in the nuclear or other particulate fractions, in both HeLa and FM 3A cells. The results suggested that the 42 degrees C-specific protein may have some function in the cytoplasm of mammalian cells during mild heat shock.

Cell Line↗
PubMed1988

[Effects of etidronate disodium (EHDP) on urogenital malignancies with bone metastasis: a multicentered collaborative evaluation].

Clinical effects of EHDP on relief of bone pain, changes in bone lesions on X-ray and 99mTc-MDP scintigram and performance status were investigated in 19 patients with bone metastasis from urogenital cancers (4 renal cell cancers, 1 renal pelvic cancer, 4 bladder cancers and 10 prostatic cancers). EHDP was effective in relieving bone pain in prostatic cancer patients with osteoblastic lesions. Bone lesions on X-ray and 99mTc-MDP scintigram were slightly improved in prostatic cancer patients with osteoblastic lesions. Administration of EHDP did not improve the performance status. Changes in laboratory data such as serum alkaline phosphatase, serum calcium and urinary total hydroxy-proline following EHDP administration indicated inhibition of osteolytic activity with no effect on bone formation in the early period of treatment (in 4 weeks) and development of both osteolytic activity and bone formation in the later period (from 8 to 12 weeks). No marked side effects were observed. EHDP seems to be effective in relieving bone pain in prostatic cancer patients with osteoblastic bone metastasis. Moreover, some diphosphonate groups including EHDP are expected to be useful to the patients with malignant hypercalcemia.

Aged↗
PubMed1987

Induction of mRNAs for heat shock proteins in livers of rats after ischemia and partial hepatectomy.

When the body temperature of rats is elevated to 42 degrees C, four heat shock proteins, with the molecular weights of 70,000, 71,000, 85,000, and 100,000 (hsp 70, hsp 71, hsp 85, and hsp 100, respectively), are induced in various tissues of rats (Fujio et al., J Biochem 101, 181-187, 1987). Heat shock proteins are induced by various stresses other than heat in varieties of cultured cells, so we studied whether heat shock proteins are induced in intact rats by different treatments. Analysis of the translation products of poly(A) + RNA isolated from the livers of rats recovering from ischemia of the liver showed that mRNAs for hsp 70, hsp 71, and hsp 85 were induced. These hsp-mRNAs were also induced in the livers of rats 6 h after a partial hepatectomy, and had returned to control levels 24 h after the surgery. These results suggested that heat shock proteins have not only the function of protection against various stresses but also physiological functions in the normal growth and development of animals.

Animals↗
PubMed1987

Induction of four heat-shock proteins and their mRNAs in rat after whole-body hyperthermia.

When the body temperature of rats was brought to 42 degrees C, four heat-shock proteins, with molecular weights of 70,000, 71,000, 85,000, and 100,000 (hsp 70, hsp 71, hsp 85, and hsp 100, respectively), were induced in various tissues of the rats. The hsp 70 was strongly induced by hyperthermia, and its accumulation was detected by Coomassie blue staining. The hsp 71 was abundant in various tissues of rats that were not heat-shocked. Analysis of translation products of liver mRNAs from heat-shocked rats also showed increased synthesis of the four heat-shock proteins, indicating that these hsp-mRNAs were induced after hyperthermia. Induction of the hsp-mRNAs was transient after hyperthermia. The four heat-shock proteins produced in various tissues after hyperthermia may be involved in homeostatic control in the heat-shock response of the rat.

Animals↗
PubMed1986

HeLa cells synthesize a specific heat shock protein upon exposure to heat shock at 42 degrees C but not at 45 degrees C.

Upon exposure to heat shock, HeLa cells synthesize a small set of proteins having the molecular weights of 70,000, 73,000, 78,000, 85,000, 92,000, and 105,000. In addition to these proteins, we found an unusual heat shock protein induced by heat shock at 42 degrees C, but not at 45 degrees C. The 42 degrees C-specific protein, the molecular weight of which was 90,000, was not produced in control cells and the induction of the protein was completely inhibited by actinomycin D. The protein was not induced by other treatments that induced most heat shock proteins. Thus, this 42 degrees C-specific protein seems to have a peculiar induction mechanism and a specific function in the cells.

Female↗
PubMed1986

Left renal vein hypertension in patients with left renal bleeding of unknown origin.

The pullback pressure from the left renal vein (LRV) to the inferior vena cava was studied in 16 patients with left renal bleeding of unknown origin (group A), 15 patients with hematuria of miscellaneous laterality (group B), and nine control subjects (group C). The mean pressure gradients were 5.0 +/- 2.0 mm Hg (mean +/- SD) in group A, 1.9 +/- 1.0 mm Hg in group B, and 1.1 +/- 0.9 mm Hg in group C. The mean pressure gradient of group A was significantly higher than that of groups B and C (P less than .001). From the results of control studies, we regarded pressure gradients greater than or equal to 3.0 mm Hg as indicative of LRV hypertension. With this criterion, 88% (14 of 16) of the patients in group A had LRV hypertension, which was considered a cause of hematuria. Analysis of the results of renal angiography in the 31 patients revealed that opacification of collateral pathways of the LRV was a significant angiographic finding in LRV hypertension.

Adolescent↗
PubMed1986

Coincidental pituitary adenoma and parasellar meningioma: case report.

We report a patient who had pituitary adenoma and parasellar meningioma coincidentally, with neither irradiation nor a history of head injury. Preoperative computed tomographic (CT) scan had shown a large intrasellar mass with ring-like enhancement; in contact with this mass, another well-enhanced mass had been shown. Histopathologically, the intrasellar mass was diagnosed as chromophobic pituitary adenoma and the other mass as meningotheliomatous meningioma. We present clinical, radiological, and histopathological findings and discuss previously reported cases of coincidental pituitary adenoma and meningioma without irradiation. This is the first case report since the advent of CT that pituitary adenoma and parasellar meningioma in contact with each other could be clearly demonstrated by CT.

Adenoma↗
PubMed1986

[Various problems concerning the treatment of benign prostatic hypertrophy--operative treatment; subcapsular prostatectomy].

We were quite puzzled to be asked to talk about open surgery for benign prostatic hypertrophy (BPH) at this symposium because transurethral resection prostatectomy (TUR-P) is now the usual procedure and open surgery is rarely performed. Problems arise when open surgery is performed rather than TUR-P as the main treatment for BPH under these circumstances and the criticism of negligence is inevitable. Cases in which open surgery was performed because the application of TUR-P seemed unsuitable are reviewed.

Aged↗
PubMed1986

Effects of sodium butyrate and dibutyryl cyclic AMP on thermosensitivity of HeLa cells and their production of heat shock proteins.

When HeLa cells were incubated at 42 degrees C for 6 h with 1 mM sodium butyrate or when cells treated with 1 mM dibutyryl cyclic AMP for 24 h were incubated at 42 degrees C for 6 h, they were more thermoresistant than heated control cells without such drugs. The production of heat shock proteins was not enhanced by the drug treatment. These results suggest that there is a factor (or factors) other than heat shock proteins that accounts for the thermoresistance of HeLa cells.

Bucladesine↗