Biomedical subjects

T Aiba

Publications and source records attributed to T Aiba.

At least 73 records · Page 4Linked to original sources

PubMed1991

Primary intracranial amelanotic melanoma--report of an autopsy case.

Primary intracranial amelanotic melanoma was verified at autopsy in a 38-year-old male. Correct diagnosis of amelanotic melanoma needs electron microscopy or immunohistochemistry, since Masson staining is negative due to the absence of melanin pigment. We adopted the following criteria for clinical use: macroscopically not dark and microscopically negative for Masson staining, but ultrastructurally various melanoma types present. Although the clinical profile of this case is consistent with melanotic melanoma, the more detailed features of primary intracranial amelanotic melanoma require future study.

Adult↗

PubMed1991

Influence of experimental rhino-sinusitis on olfactory epithelium.

The pathology of olfactory epithelium in rhino-sinusitis caused by experimental bacterial infection was studied by scanning electron microscopy. Masses of non-ciliated or microvillous cells were observed on the marginal region of olfactory epithelium as spotted or insular lesions 1 week after onset of inflammation. These masses sporadically contained respiratory ciliated cells which might have replaced cells of olfactory epithelium during recovery from inflammatory damage. Prolonged inflammation with repeated flare-ups promoted the transformation to the respiratory ciliated epithelium at the margin of the olfactory epithelium and made the boundary between olfactory and respiratory epithelium intricate and obscure. The present study suggests that repeated infection with aging could be responsible for a decreased olfactory region.

Aging↗

PubMed1991

Morphological study of clinically nonsecreting pituitary adenomas in patients under 40 years of age.

Clinically nonsecreting pituitary adenomas removed at surgery from 69 patients under 40 years of age were studied by histological, immunocytochemical, and transmission electron microscopic examination. By morphological analysis, 19 tumors were found to be null-cell adenomas, 17 silent gonadotroph adenomas, 14 silent subtype 3 adenomas of unknown cellular origin, 13 silent subtype 1 or subtype 2 corticotroph adenomas, three oncocytomas, and three silent thyrotroph adenomas. These results indicate that the incidence of null-cell adenomas and oncocytomas, which are known to be the most common types of nonsecreting pituitary adenomas in patients over 40 years of age, is relatively low in younger patients. This trend is even more obvious in patients younger than 30 years of age. It can be concluded that clinically nonsecreting pituitary adenomas represent a heterogeneous group morphologically, and that the incidence of the different tumor types varies depending on the patient's age. These findings underline the importance of careful morphological studies. It is proposed that, in order for the correct morphological diagnosis to be made, tumors removed surgically from patients with clinically nonsecreting pituitary adenomas (especially younger patients) should be investigated not only by histological means but also by immunocytochemical and electron microscopic examination. The information obtained from such analysis may be useful in assessing prognosis and deciding on the appropriate treatment.

Adenoma↗

PubMed1991

[Two cases of pure agraphia developed after thalamic hemorrhage].

We have observed two cases suffered from left thalamic hemorrhage, that showed pure agraphia. The first case was a 49 year-old, right handed male, who was educated through 11th grade. The CT scan revealed left thalamic hemorrhage with ventricular casting. The second case was a 48 year- old, right handed male, who was educated through 9th grade. The CT scan revealed left thalamic hemorrhage which is smaller than that of the first case, without intraventricular rupture. With a standard neuropsychological evaluation performed at chronic stage, neither cases showed oral language disorder, apraxia and agnosia. On the Wechsler Adult Intelligence Scale, total IQ of the first and second case were 71 and 80 respectively. Each case developed severe writing disorder. The first case showed severe neographism and scrawl, mild literal paragraphia, which were frequently accompanied with perseveration. The second case showed literal paragraphia and no response, but neographism was not detected. The common characteristics of both cases were; 1) intact copy writing. 2) discrepancy between difficulty in writing "Kana" and that in "Kanji". 3) anosognosia of agraphia. The cerebral blood flow study by 123I-IMP Single photon emission computed tomography revealed low perfusion of the left cerebral hemisphere in both cases. From these findings, we concluded that dysfunction of the left cerebral cortex is responsible for producing agraphia in these cases.

Agraphia↗

PubMed1991

Reverse hemolytic plaque assay. Electron microscopic observation of plaque-forming single adenoma cells in GH producing adenomas.

In this study, 3 GH-producing adenomas were studied as materials to clarify the usefulness of electron microscopic investigation of plaque-forming single adenoma cells, and ultrastructural morphometric comparisons were made to determine whether some differences exist at the cytoplasmic organelle level between small plaque-forming cells and large plaque-forming cells. In two cases, the relative cytoplasmic volume density of Golgi apparatus and lysosomes were significantly greater and the diameter of seretory granules were significantly smaller in large plaque-forming cells compared to small plaque-forming cells. Moreover, in one of them, not only the diameter but also the cytoplasmic volume density of secretory granules were significantly smaller in large plaque-forming cells. These findings suggest a greater secretory granule synthesis and internal granule destruction, and faster granules secretion at an early stage of formation in large plaque-forming cells compared with small plaque-forming cells. It became apparent through this study that electron microscopic investigation of plaque-forming single cells is practically useful since plasma membrane and cytoplasmic organelles were preserved well after processing for EM in most plaque-forming cells.

Adenoma↗

PubMed1990

Moment analysis of drug disposition in kidney. III: Transport of p-aminohippurate and tetraethylammonium in the perfused kidney isolated from uranyl nitrate-induced acute renal failure rats.

A different manner of insufficiency of renal epithelial cell transport between the organic anion and cation, p-aminohippurate and tetraethylammonium, respectively, was observed in the perfused kidney isolated from uranyl nitrate-induced acute renal failure (ARF) rats. The single-pass outflow pattern of the perfused kidney was analyzed by noncompartmental moment analysis. The active tubular secretion was impaired faster than the reduction of glomerular filtration, and the tetraethylammonium secretion decreased at an earlier stage of ARF than p-aminohippurate. The apparent uptake rate constant from blood to cells of p-aminohippurate was reduced with the progress of ARF and associated with the amount of this drug secreted, whereas the uptake rate constant of tetraethylammonium did not change until the late stage of ARF. The mean residence time in renal epithelial cells of tetraethylammonium was prolonged with reduction of the amount to be secreted, while that of p-aminohippurate remained unchanged. Therefore, the uptake of p-aminohippurate across the basolateral membranes decreased gradually, and the transport across the brush border membranes was still unchanged after uranyl nitrate treatment. On the other hand, the secretion of tetraethylammonium from cells to lumen was impaired at first, and then the uptake from blood to cells was impaired. These results suggest that impairment by uranyl nitrate-induced ARF appears at the carrier-mediated transport process of the epithelial cell membranes for both organic anions and cations.

Acute Kidney Injury↗

PubMed1990

Moment analysis of drug disposition in kidney. II: Urine pH-dependent tubular secretion of tetraethylammonium in the isolated perfused rat kidney.

Effects of urine pH on the renal tubular secretion of an organic cation (tetraethylammonium, TEA) and an organic anion (p-aminohippurate, PAH) were investigated using the isolated erythrocyte-perfused rat kidney. The method was based on a multiple indicator dilution experiment and noncompartmental moment analysis. Treatment with sodium bicarbonate and sodium dihydrogen phosphate increased and decreased urine pH, respectively, but affected neither the condition of the perfused kidney nor the renal handling of albumin and inulin. In TEA studies, the increase of urine pH prolonged the mean residence time in renal epithelial cells (T cell) and reduced the apparent secretion intrinsic clearance, but did not influence the volume of distribution in the kidney (Vd drug). The decrease of urine pH did not affect these kinetic parameters. By contrast, PAH secretion was constant against the change of urine pH. Since any change in the basolateral membrane transport is reflected in Vd drug, the net transport from blood to cells can be regarded as similar under these treatments. On the other hand, the prolonged T cell of TEA with the increased urine pH suggested a slow transport from cells to lumen across the brush-border membranes. The present results coincide with the hypothetical mechanism that organic cations are secreted via an active transport system, coupled to the countertransport of H+ into cells. In conclusion, the present method is useful to separately evaluate the transmembrane transport across both sides of the renal epithelial cells in a morphologically intact kidney.

Animals↗

PubMed1989

Postoperative prognostic indicators of control of acromegaly.

Changes in growth hormone basal levels and growth hormone dynamic tests such as thyrotropin-releasing hormone and luteinizing hormone-releasing hormone tests, and the glucose tolerance test were evaluated during a follow-up period of 1-17 years in 17 acromegalic patients. In these cases, mean growth hormone basal levels obtained 1-2 months after surgery had dropped to levels below 5 ng/mL. In 11 of the patients, the 1-2 months postoperative mean growth hormone basal levels were reduced to less than 3 ng/mL. In these patients, abnormal growth hormone responses to these dynamic tests were not present and mean growth hormone basal levels remained below 3.0 ng/mL during the follow-up period of 1-6 years. In contrast, the six other patients' 1-2 months postoperative mean growth hormone basal levels were between 3 and 5 ng/mL. Of these, four presented abnormal responses in at least one of these three dynamic tests 1-2 months postoperatively, and three exhibited a rise in growth hormone basal levels after intervals of 1-3.5 years after surgery. It is concluded that the restoration of normal growth hormone response to the dynamic tests is better related to the value of the mean growth hormone basal levels obtained 1-2 months postoperatively being less than 3 ng/mL rather than it is to the conventional criterion of the growth hormone basal levels being less than 5 ng/mL.

Acromegaly↗

PubMed1989

ACTH determination in a petrosal sinus venous specimen after corticotrophin releasing factor provides the best clue on the laterality of microadenoma in Cushing's disease.

A 42-year-old woman with Cushing's disease was endocrinologically cured after transsphenoidal selective excision of a left-sided microadenoma. Simultaneous samplings from the bilateral inferior petrosal sinuses with ovine corticotrophin-releasing factor (CRF) stimulation were performed preoperatively to evaluate some relations between the localization of a possible microadenoma and the levels of ACTH in inferior petrosal sinuses. The data for the venous samplings were as follows:-(1) The basal levels of ACTH obtained simultaneously from both inferior petrosal sinuses and peripheral vein were about the same. (2) A significant difference, with a high level of ACTH from the ipsilateral side of the microadenoma, was demonstrated after CRF stimulation. (3) The magnitude of increase in ACTH on the contralateral side after CRF was similar to that of the peripheral response. It is recommended that all patients with ACTH dependent Cushing's syndrome and negative radiological findings should have bilateral simultaneous inferior petrosal venous sampling with CRF stimulation.

Adenoma↗

PubMed1989

Cerebellopontine angle lipoma with abnormal bony structures--case report.

A cerebellopontine angle lipoma accompanied by a bony protrusion from the left petrous pyramid was discovered in a 35-year-old female with a 10-year history of vertigo and a 3-year history of left tinnitus. Following subtotal removal of the tumor, the frequency of vertigo increased and she was deaf in the left ear. The symptoms, radiological and pathological features, and surgical management of this rare tumor are discussed.

Adult↗

PubMed1989

Cystic acoustic neurinomas--report of two cases.

Two cases of large, cystic acoustic neurinoma are described. On computed tomographic scans, cystic acoustic neurinomas resemble, and may be confused with, other tumors of the cerebellopontine angle. A cystic acoustic neurinoma should be considered in the event of a large, cystic cerebellopontine angle tumor, especially if there is no significant hearing loss and no destruction of the internal auditory canal.

Adult↗

PubMed1989

[Brain metastasis of ovarian cancer treated by chemotherapy including cis-platin: a case report].

A 57-year-old woman was admitted to our department with headache and dizziness. About 8 months ago, she suffered from ovarian cancer disseminated in pleura and peritoneum, and was treated successfully with CAP therapy only (Cis-platin, Adriamycin and Cyclophosphamide). Intracerebellar metastasis of ovarian cancer was suspected on CT scan, and CAP therapy was employed again. She was relieved from all symptoms a week after starting the therapy. Follow up CT scan showed complete remission of the lesion. She was well for about 3 months, but was admitted again because of consciousness disturbance and headache with multiple brain metastasis. PVB therapy (Cis-platin, Vinblastine and Pepleomycin) was employed this time, and complete remission was seen again. But regrowth of intraabdominal mass lesion appeared, and she died from multiple organ failure 5 months after PVB therapy. Autopsy was not permitted, but CT scan 3 days before death revealed no intracranial lesion. Distant metastasis of ovarian cancer may become more prevalent with the development of combination chemotherapy, but no case of brain metastasis has been reported to have been treated with chemotherapy only. The authors suggest the possibility of successful treatment of such a lesion with chemotherapy including Cis-platin.

Adenocarcinoma↗

PubMed1989

[A case of unilateral masticatory spasm without hemifacial atrophy].

Masticatory spasm is a rare clinical feature and mostly associated with disorders of general movement. Usually it occurs bilaterally. Unilateral masticatory spasm is mostly associated with facial hemiatrophy. So, unilateral masticatory spasm without facial hemiatrophy is extremely rare. As far as we have investigated, only one case has been reported in the literature. We will report one more case herein, with some discussion on its pathogenesis. Case report A 44-year-old man presented with a 8 month history of slowly progressive recurrent spasm of the left masseter muscle. The spasm was exaggerated by tension and lasted for up to 10 seconds. Several drugs could not reduce the frequency of spasm, but only clonazepam could decrease it slightly. On admission, the spasm lasted usually for 1 or 2 seconds. Except for masticatory spasm, neurological examination comprising trigeminal nerve function, was normal and facial atrophy was not observed. On the contrary, hypertrophy of the left masseter muscle was noted. Needle electromyography (EMG) study revealed synchronized spasm discharges of the ipsilateral masseter, lateral and medial pterygoid muscles. All of other investigations, including CSF analysis, electroencephalography, somatosensory evoked potential, visual evoked potential, CT scan and vertebral angiography, showed normal findings. After all, we could not find any apparent organic lesions which cause masticatory spasm, so surgical treatments were not carried out. He was discharged and now, continues to take clonazepam daily.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1988

Moment analysis of drug disposition in kidney: transcellular transport kinetics of p-aminohippurate in the isolated perfused rat kidney.

The mean renal epithelial cell residence time, Tcell, was defined as a model-independent characteristic of the transcellular transport process in the isolated perfused kidney. The transcellular transport process includes transport at the basolateral membrane, diffusion in the cytosol, and transport at the brush border membrane. The parameter Tcell represents the mean time for the drug secreted from the tubules to pass through the renal epithelial cells, and is calculated as the difference of the mean urinary transit time between secreted drug and inulin in the single-pass perfusion system. Therefore, the urinary excretion rate-time course is indispensable to evaluate Tcell. p-Amino-hippuric acid was used as a model compound. The bovine erythrocytes in the perfusate kept the isolated kidney in an almost constant physiological condition, including secretion function. The renal vein outflow curves were also analyzed by the use of moments. The dispersion in the catheter was corrected by a deconvolution. The apparent secretion intrinsic clearance and the apparent volume of distribution were calculated from the moments. The present method will be useful for analysis of the transcellular transport mechanism and the effect of disease states on renal transport of drugs.

Aminohippuric Acids↗

PubMed1988

Intraoperative identification of the central sulcus: a practical method.

A practical method of intraoperative identification of the central sulcus using cortical evoked potentials (EP) was reported. The method herein proposed is unique with stimulation to the trigeminal and tibial nerve in addition to median nerve stimulation, depending on the location of the lesion. Thus, a wide coverage of the rolandic fissure was possible. Eighteen adult patients with peri-rolandic lesions were investigated. Fourteen cases had a malignant tumour but all except 3 showed only a minor neurological deficit preoperatively. In 13 cases, the central sulcus could be identified through the phenomenon of the phase-reversal of cortical EP across the central fissure. Of the remaining 5 cases, cortical EP were not detected in 3 (all showed hemiplegia and/or aphasia) and EP without phase-reversal were obtained in 2. As a result, in most cases showing only a trivial neurological deficit before surgery, aggressive removal of the tumour was successfully carried out without producing severe motor dysfunction.

Adult↗

PubMed1988

[Bacterial intracranial aneurysms associated with infectious endocarditis--report of 3 cases].

Three cases of bacterial intracranial aneurysms associated with infective endocarditis are reported. All of the patients were successfully treated by various combinations of cardiac surgery, neurosurgery and chemotherapy with antibiotics. Case 1: A 39-year-old female was admitted with the complaint of sudden onset of severe headache following persistent fever of several month's duration. CT scan revealed a left frontal old hematoma and angiography detected an aneurysm located in the frontal ascending branch of the left middle cerebral artery. After 2 weeks' antibiotic therapy, the second angiography showed the aneurysm to be decreased in size. The third angiography, performed 2 weeks after cardiac valve replacement for infective endocarditis, demonstrated complete resolution of the aneurysm. Case 2: A 19-year-old male entered hospital with high fever and chills. In addition to infective endocarditis, CT scan and angiography revealed an aneurysm arising from the distal portion of the left posterior cerebral artery. The patient was treated with high dose antibiotics and then his general condition improved. However, angiography examined 4 weeks after the initial study demonstrated the aneurysm to be apparently enlarged. Therefore, the aneurysm was excised before cardiac surgery. Repeated angiography after valve replacement showed no further aneurysm. Case 3: A 30-year-old female was admitted on the diagnosis of infective endocarditis and meningitis. CT scan showed abnormal density areas in the right frontal lobe and the left temporal lobe.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1987

[Causative factors of recurrence of chronic subdural hematoma].

Burr hole opening and irrigation of hematoma is now a widespread simple technique for the treatment of chronic subdural hematoma (CSH). However, recurrence of hematoma has been sometimes experienced after initial treatment. The purpose of this report is to analyze the causative factors in recurrence of the hematoma after the burr hole opening and irrigation. Out of 68 adult cases of CSH treated by burr hole opening and irrigation technique at Toranomon Hospital during the past nine years, 11 cases (16.2%) showed recurrence of symptoms due to reaccumulation of hematoma after the 1st operation. They were compared with non-recurrence cases from the viewpoint of clinical signs, symptoms and course and serial CT findings. But there was no statistically significant difference between them. The causative factors of recurrence of CSH were analyzed and divided into four categories. Type 1 (3 cases): specific promoting factors--Primary intracranial hypotension (2 cases) and anticoagulant therapy (1 case). Type 2 (1 cases): immature timing of operation. Type 3 (4 cases): other causes probably due to operative procedure--Insufficient postoperative external drainage. Type 4 (3 cases): unknown cause. Several authors have reported causative factors of recurrence of CSH so far, but they are still controversial. An additive treatment in the cases involving specific factors, and planning the timing and some procedures of operation are proposed in order to avoid recurrence of CSH.

Adult↗

PubMed1987

[Trigeminal somatosensory evoked potentials: II. Some clinical experiences].

Compared to other somatosensory evoked potentials (SEP), little information has been published so far on trigeminal somatosensory evoked potentials (TSEP) in the various kind of disorders. This may be due to few recording technique suitable for clinical practice. We previously reported a new recording method and showed the normal pattern of TSEP. The purpose of this report is to examine its reliability for clinical use. Sixty patients, with either a complaint of facial numbness or an organic lesion supposed to involve facial sensory pathway, were investigated. Their age ranged from 13 to 74 years old (mean 47.0). They consisted of 34 organic lesions (30 brain tumors and 4 cerebrovascular diseases) and 26 non-organic lesions (16 hemifacial spasms, 6 trigeminal neuralgias and other miscellaneous disorders). TSEP was recorded by the stimulation of the half of the contralateral upper or lower lip with the clip-shaped electrode. C'5 or C'6 (midpoint between Cz and the external auditory porus) was used as an active electrode and Fz as a reference. Two hundred or four hundred responses were averaged by a Nicolet Pathfinder II. All recordings were repeated at least twice to confirm the reproducibility. (1) Among 21 patients with a complaint of facial numbness except for neuralgia, the abnormality rate of TSEP was significantly different (p less than 0.02) between organic and non-organic lesions. The former was 87.5% (14 out of 16 cases) and the latter was 20% (1 out of 5 cases).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗