Biomedical subjects

K Arita

Publications and source records attributed to K Arita.

At least 145 records · Page 8Linked to original sources

PubMed1994

[Oral complication of sublabial transsphenoidal approach and advantage of endonasal transsphenoidal approach].

In order to know the exact incidence of oral complications due to the sublabial transsphenoidal approach, the authors meticulously heard the complaints of 46 patients, who had undergone the approach more than 3 months before. The incidence of the patients who had one or more complaints concerning the oral region was 52.2%. Dysesthesia of the upper lip was most frequent (37%), followed by upper lip pain (17.4%). These complaints were more marked in two patients who had undergone operations using the sublabial approach twice. Among the nine patients with dentures, the dentures had to be remade in three patients because of gigival atrophy several months after the use of the sublabial approach. With a view to overcoming these complications, the authors adapted the endonasal transsphenoidal approach in 13 patients. There was no inconvenience during surgery while this approach was being used, and there were no postoperative oral complications. Among three patients using dentures, there were none who needed remodeling of their dentures. In nine patients, the tension reducing incision was made in the bottom of the columella, which caused no cosmetic problem. Furthermore, the time consumed for approaching the sphenoid sinus was less than that required when using the sublabial approach. In conclusion, the following type of patient is believed to be an appropriate candidate for endonasal approach. A patient who has a relatively smaller sellar lesion and 1) An acromegalic patient whose nostril is relatively large, 2) An elderly patient using dentures, 3) A patient who has undergone previous transsphenoidal surgery, or 4) A patient whose columellar crease is hidden.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenoma↗

PubMed1994

Rathke cleft cysts: correlation of enhanced MR and surgical findings.

PURPOSE: To describe the gadolinium-enhanced MR findings of Rathke cleft cyst correlate them with the surgical findings, and define those preoperative findings that differentiate this lesion from other sellar and juxtasellar tumors. METHODS: We studied 18 patients who were diagnosed as having Rathke cleft cyst pathologically. These patients were imaged with T1- and T2-weighted coronal and sagittal spin-echo sequences. Fifteen of these patients received gadopentetate dimeglumine. RESULTS: In eight patients, the cyst showed low intensity on T1-weighted images and high intensity on T2-weighted images. At surgery, the cyst fluid was cerebrospinal fluid-like or light brown in five patients, motor oil-like in one patient, and milky in two patients. In 10 patients, cysts showed isointensity to high intensity on T1-weighted images and had various intensity on T2-weighted images. All 10 contained milky fluid. In three patients the intensity of fluid was heterogeneous. A waxy nodule was found in two patients. The position of the normal pituitary gland confirmed by surgery in all cases coincided with enhancement on MR imaging. The variable position of the normal pituitary gland was clearly identified in the sagittal images. The cyst walls showed no enhancement by gadopentetate dimeglumine. CONCLUSIONS: Because Rathke cleft cysts show variable intensities on MR, the diagnosis is often difficult when based on MR signal intensity values alone. MR imaging with gadopentetate dimeglumine does assist in the diagnosis of Rathke cleft cysts. Diagnostic clues include the lack of cyst wall enhancement and displacement of the normal pituitary gland.

Adenoma↗

PubMed1993

MRI visualization of complete bilateral optic nerve involvement by pituitary adenoma: a case report.

With large pituitary adenomas, the optic nerves and chiasm usually lie on the tumour capsule and are displaced superiorly. We report a large invasive pituitary adenoma, with complete involvement of both optic nerves. Review of the preoperative MR images demonstrated the optic nerves, with signal intensity close to that of cerebral white matter, and different from the flow void of the basal cerebral arteries. Correlation of this observation with intraoperative findings is discussed.

Adenoma↗

PubMed1993

The function of the hypothalamo-pituitary axis in brain dead patients.

In order to find out the function of the hypothalamo-pituitary axis in brain dead patients, pituitary and hypothalamic hormone concentrations were measured and several anterior pituitary releasing tests were carried out in 39 brain dead patients. In addition, cerebral blood flow measurements were simultaneously performed. In almost all cases, the blood concentration of pituitary and hypothalamic hormones were above the sensitivity of the assay. Anterior pituitary releasing tests indicated that efficient functions of the hypothalamus were severely suppressed, while the normal secretory mechanism of the anterior pituitary was partially preserved in brain dead patients. Histological changes of hypothalamic neurons varied from barely detectable ghost cells to nearly normal cells even in the same case. Although, the remaining circulation seemed not to be sufficient enough to maintain integrated hypothalamo-pituitary function, as shown by the examinations of cerebral blood flow, the presence of hypothalamic hormones in the systemic circulation suggests that these hormones were released and carried from the hypothalamus by minimal flow which is preserved even after the diagnosis of brain death.

Adolescent↗

PubMed1993

Hyperaemia prior to acute cerebral swelling in severe head injuries: the role of transcranial Doppler monitoring.

Acute cerebrovascular congestion after a closed head injury is significantly related to intracranial hypertension. As an indirect method of cerebral blood flow measurement; transcranial doppler sonography (TCD) provides a rapid and noninvasive assessment of cerebral haemodynamics, including hyperaemic conditions. TCD examinations was serially performed in 35 patients with severe head injury with intact cerebral circulation; i.e. the mean flow velocity (MFV) patterns of the middle cerebral artery (MCA) did not show signs of cerebral circulatory arrest such as systolic spike, to and fro, or no flow. The results showed that the MFV of the MCAs and ipsilateral extracranial internal carotid arteries (ICAs) in 9 of these patients increased sharply and pulsatility index (PI) decreased during 48-96 hours after the injury. This was soon followed by patterns of high intracranial resistance, consistent with elevated intracranial pressure (ICP) in monitored patients and acute brain swelling on repeated computed tomographic (CT) scans. The correlation between increased MFVs, decreased PIs, and cerebral haemodynamic changes leading to acute brain swelling is discussed. The number of patients who ended with severe disability, vegetative state, or death was 66% in this group of 9 patients, compared to only 34% for the 35 patients overall with severe head injury. Though the morbidity and mortality rates largely depend on the primary injury, the presence of acute cerebral swelling aggravate the grave course in these patients. And the ability of TCD to monitor the hyperaemic state prior to oedema should lead us to adjust the therapy in order to minimize the secondary insult related to intracranial hypertension.

Adult↗

PubMed1993

Cerebral circulation in moyamoya disease: a clinical study using transcranial Doppler sonography.

Transcranial Doppler sonography was performed on eight patients diagnosed as Moyamoya disease. Angiographically, the patients-four adults (mean age 42) and four children (mean age 7.7)-underwent a complete six- or five-vessel angiographic study. The results showed the following: (1) Despite the presence of stenosis, all middle cerebral arteries showed very low-flow velocity compared to their ipsilateral distal internal carotid arteries. In adult cases, the difference was very significant (p < 0.02). (2) Relatively high-flow velocity was observed in the posterior cerebral arteries of children, and in the ophthalmic arteries of adult cases. (3) In several occasions, very low-flow velocity values were still detected despite the fact that with angiography, the respective arterial segments were hardly opacified. The relation and discrepancy between these results and the angiographic findings, and the potential application of transcranial doppler in assessing and grading the severity of moyamoya disease are discussed.

Adolescent↗

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

[Chemotherapy with high-dose carboplatin for inoperable non-small cell lung cancer].

The clinical efficacy and side effects of high-dose CBDCA therapy were studied in 35 cases of inoperable non-small cell lung cancer. A positive effect was obtained in about 30% of the subjects, all of who were squamous cell carcinoma patients. Incidence of clinical side effects was very low, thrombocytopenia being the major hematologic side effect. AUC, calculated from periodic measurements of free-Pt concentration in 19 subjects, was sensitive renal function, having a positive correlation with Cmax and a negative correlation with platelet nadir levels. This finding suggested the importance of establishing optimum dose levels with regard to pharmacokinetics. Patients in whom bone marrow suppression did not hamper continued therapy were treated as outpatients, many of whom retained sufficient QOL while undergoing outpatient therapy. Considering the present status of chemotherapy for NSCLC, characterized by the lack of long-term clinical efficacy and the presence of severe side effects, the present therapy is of great importance, since it can be continued with constant efficacy rates while maintaining good PS.

Adult↗

PubMed1993

[Studies on 13 cases of active tuberculosis diagnosed at autopsy for the first time].

It is reported not only that the incidence of active tuberculosis has not decreased but also that the cases of active tuberculosis who had been diagnosed at autopsy for the first time may have increased. The background factors and clinical courses of 13 cases of active tuberculosis whom we could not diagnose as tuberculosis until autopsy were investigated. According to the autopsy reports, the three fourths of the cases had active tuberculosis lesions in several organs as miliary tuberculosis. All of the cases were treated in serious condition of liver cirrhosis, leukemia, and other malignant diseases. Although fever of unknown origin was an important symptom, it was difficult to make a correct diagnosis because the fever was thought to be originated not from active tuberculosis but from the underlying diseases themselves. It was also difficult to diagnose from chest x-ray findings unless tuberculosis was suspected clinically. The education about tuberculosis should be held repeatedly. And we should try to think from different direction for the strange and unexpected clinical features of the patients with liver cirrhosis, leukemia, and other malignant diseases.

Aged↗

PubMed1993

[Peduncular hallucination in brain stem cavernous angioma: a case report].

A case of brain stem cavernous angioma associated with peduncular hallucination is reported. A 68-year-old man was admitted with complaints of left sensory disturbance. On the evening of the first hospital day, he developed vividly formed hallucinations. The hallucinations were accompanied by sleep disturbance and agitation. At approximately 2:00 am, he began to feel as though he could see his daughter watching television in a room. At one point he saw vivid pictures. MRI revealed a round mass with a mixed signal intensity core surrounded by a low signal intensity rim in the right brain stem. On the 10th hospital day, there were no hallucinations. On October 12th suboccipital craniectomy was performed and cavernous angioma and the surrounding hematoma was partially removed. Soon after that the patient was discharged with improvement of both ocular movement and left-sided sensory disturbance.

Aged↗

PubMed1993

[Venous thrombosis after closed head injury: a report of two cases presenting as intracranial hypertension].

Although sinus thrombosis occurs owing to various causes, sinus thrombosis after closed head injury is rarely reported. The authors encountered 2 cases with sinus thrombosis in whom intracranial hypertension occurred after closed head injury. In case 1, left abducens and oculomotor palsy developed as a false localizing sign, together with symptoms of intracranial hypertension 10 days after head injury. Using angiography, we made a diagnosis of stenosis of the superior sagittal sinus. Since the symptoms were aggravated under conservative treatment, V-P shunt was performed, but impaired vision was not improved. In case 2, symptoms of intracranial hypertension occurred 10 days after head injury. We performed magnetic resonance angiography (MRA) and made a diagnosis of stenosis of the bilateral transverse sinuses. The symptoms improved under conservative treatment. The use of conventional angiography has been the most reliable for a diagnosis of sinus thrombosis, but MRA will become useful from now on. For diagnosis, it is important to suspect sinus thrombosis after closed head injury. Surgical decompression is required for patients in whom symptoms are aggravated under conservative treatment.

Child↗

PubMed1992

[Treatment of pituitary adenomas].

There has been a dramatic development in the treatment of pituitary adenomas during the last two decades. The main factors which led to this development were the introduction of transsphenoidal surgery, the development of new imaging modalities such as computed tomography (CT) and magnetic resonance imaging (MRI) and the introduction of newer dopaminergic agents. Present status of the treatment of pituitary adenoma is reported here. This report is based on the experiences of 381 cases of pituitary adenomas treated at the Department of Neurosurgery, Hiroshima University School of Medicine within the last 16 years. There are some problems which have to be solved in order to achieve further development in the treatment of pituitary adenomas. Our experience in this field and a need for future development are listed below. 1) The transsphenoidal adenomectomy gives high cure rates in cases of micro and expansive prolactinomas and growth hormone secreting adenomas. 2) Results of the transsphenoidal surgery in cases of ACTH secreting adenomas is not satisfactory. In order to get higher cure rate, a more elaborate operative techniques and an introduction of more effective drug therapy are needed. 3) Further safety and curability in pituitary surgery will be achieved by the exploitation of new imaging modalities such as MRI.

Adenoma↗

PubMed1992

Intracranial germ-cell tumor with synchronous lesions in the pineal and suprasellar regions: report of six cases and review of the literature.

The features of intracranial germ-cell tumor with synchronous lesions in the pineal and suprasellar regions (GCTSPS) in six patients were investigated. GCTSPS accounted for 12.8% of all germ-cell tumors (GCT) in our brain tumor study group. In all cases, the initial symptoms were attributable to the suprasellar lesion, and symptoms due to the pineal GCT developed only after admission. Five of the six cases were histologically diagnosed as germinoma. In all cases, tumors of both regions disappeared after irradiation, resulting in no recurrence for an average of 55.3 months. Our experience and reports in the literature suggest that GCTSPS is highly sensitive to radiation in most cases, although some reports indicated that recurrence is frequent after radiation therapy alone. It is suggested that histological diagnosis in one of the GCTSPS lesions is undertaken to make a plan for the following treatment.

Adolescent↗

PubMed1992

Transcranial Doppler sonography in carotid-cavernous fistulas: analysis of five cases.

Transcranial doppler sonography was performed transorbitally in five patients clinically diagnosed as unilateral carotid-cavernous fistula. Dural arteriovenous malformation related-shunts were detected in all the patients. In the normal eyes, the only doppler signals observed at an insonation depth of 45 to 55 mm were those of the ophthalmic artery. In the affected eyes, abnormal doppler signals with relatively higher flow velocity and lower resistance were observed. In three of the cases, these abnormal signals showed a flow directed anteriorly or away from the cavernous sinus, consistent with changes in the ophthalmic veins caused by the presence of the shunts. In two cases, however, the observed flows were directed posteriorly, the normal direction of these veins. The possible explanations for this discrepancy are discussed in relation with angiographic findings. The use of transcranial doppler might provide a better understanding about hemodynamic changes in carotid cavernous fistulas.

Aged↗

PubMed1992

Microprolactinoma invading the cavernous sinus--report of three cases.

Three cases of microprolactinoma with cavernous sinus invasion on magnetic resonance imaging are reported. High-resolution computed tomographic scans did not demonstrate the cavernous sinus involvement. Magnetic resonance imaging is indispensable to detect cavernous sinus invasion before treatment (transsphenoidal surgery or bromocriptine treatment) of a microprolactinoma.

Adult↗

PubMed1992

Effect of long-term treatment with somatostatin analogue (SMS 201-995) on pituitary tumor shrinkage in acromegaly--report of two cases.

The effect of long-term somatostatin analogue (SMS 201-995) treatment in two acromegalic patients is reported. Continuous tumor shrinkage was observed even after 129 and 139 weeks of treatment with 600 micrograms of SMS 201-995 daily. A huge and firm adenoma underwent shrinkage during treatment with SMS 201-995. No serious side effect appeared during 160 weeks of treatment. SMS 201-995 has a longterm tumor shrinkage effect and improves endocrinopathies.

Acromegaly↗

PubMed1992

Moyamoya disease associated with pituitary adenoma--report of two cases.

Moyamoya disease associated with prolactin (PRL)-producing pituitary adenomas occurred in two females with elevated blood PRL levels (285 and 120 ng/ml). Computed tomography revealed cystic tumors extending from the sella turcica to the suprasellar cistern. Carotid angiography demonstrated stenoses or obstructions of the bilateral internal carotid arteries at their end point and development of bilateral basal moyamoya vessels. Histological diagnosis in one case was PRL-producing chromophobe adenoma. No stigmata of neurofibromatosis or any history of irradiation was found. Compression of carotid arteries by the tumor was unlikely. These cases should therefore be classified as moyamoya disease accompanied by brain tumor, a very rare occurrence. The hypothalamic disturbance caused by moyamoya disease may have induced the hyperprolactinemia, resulting in secondary prolactinoma.

Adenoma, Chromophobe↗

PubMed1992

Bond strengths of various materials to dentin using Amalgambond.

This study evaluated the bond strength of four restorative materials to dentin using Amalgambond. Two high-copper amalgams [Tytin; spherical, (T) and Epoque 80; lathe-cute, (E)], a gallium alloy [Gallium Alloy GF (G) and a resin composite [P-50 (P)] were tested. The polished dentin surface was treated with dentin-enamel activator (10 seconds), washed, dried, and adhesive agent was applied (30 seconds). In group A, the dentin adhesive was placed onto the dentin and while still wet, T, E, or G was condensed in cylinders (4 mm diameter) with condensation forces suggested by the manufacturer for a clinical situation. In group B, the cylindrical specimens of restorative material were allowed to set and then adhered to the treated dentin using the adhesive system. For the composite (control), the adhesive was applied to the treated dentin and while still wet, P was layered into the cylinder and cured for a total of 90 seconds. After storage in water (37 degrees C) for 24 hours, all the specimens were tested for tensile bond strength. This study revealed that the bond strength of P was significantly higher than the other materials tested and also that amalgam allowed to set for 1, 6 or 24 hours before adhesion to dentin had a significantly greater bond strength than freshly condensed amalgam. Although the desired high bond strength did not develop in the bonding of the metallic restorative materials, signs of bonding were found.

Analysis of Variance↗