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Biomedical subjects

S Kuwabara

Publications and source records attributed to S Kuwabara.

At least 145 records · Page 8Linked to original sources
PubMed1991

[A case of sellar germinoma which was misdiagnosed as pituitary adenoma].

The authors reported a rare case of sellar germinoma which was misdiagnosed as nonfunctioning pituitary adenoma. A 32-year-old woman was admitted to our hospital because of amenorrhea and disturbance of left visual acuity. She had become amenorrhagic after her second delivery two years before. Neurological examination revealed she was normal except for diminished left visual acuity (Rt. = 1.2, Lt. = 0.5). The general condition was good. Urine volume and its specific gravity were within normal range. Endocrinological examination showed hyperprolactinemia (PRL 72 ng/ml) accompanied with impairment of GH, TSH, LH and FSH's reserve. Basal levels and reserve of the blood cortisol were normal. AFP and hCG were within normal range. CT scan revealed a homogenously enhanced intrasellar tumor which had a suprasellar portion (vertical length: 15 mm). T1 weighted MRI revealed low intensity tumor, and T2 weighted image revealed high intensity tumor. Sagittal MR image with gadolinium enhancement showed the pituitary gland anterior to the tumor. Transsphenoidal removal was performed. The histological diagnosis was pure germinoma. After the operation, the intracranial and spinal disseminations were disclosed. Complete neuraxis irradiation resulted in the complete remission of the tumor. Sellar germinoma without diabetes insipidus is considered to be very difficult to diagnose preoperatively. However, the authors proposed that anterior shift of the pituitary gland in sagittal MR image may be a clue to the diagnosis of sellar germinoma.

Adenoma↗
PubMed1991

[Chronic inflammatory demyelinating polyradiculoneuropathy presenting localized radiculopathy as an initial symptom].

We reported a patient with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), presenting localized radiculopathy as an initial symptom. The patient, a 38-year-old man, developed muscle atrophy of right shin and calf. In April 1988, neurological examination revealed decreased superficial sensation and muscle atrophy in right L-4 distribution. MRI of the lumbar spinal cord and myelography were negative. In April 1989, he was admitted to Chiba University Hospital. There were slight weakness of right ankle extension and flexion, muscle atrophy of bilateral shin and calf (that of the right leg was more marked), decreased sensation of polyneuropathy type in all modalities and generalized hypo- or a-reflexia. Nerve conduction study revealed marked prolongation of F response and focal conduction block in various site. The CSF was acellular and total protein was 177 mg/dl. Sural nerve biopsy disclosed decreased number of large myelinated fibers and scattered thin myelinated fibers. This case indicates that CIDP may present localized radiculopathy in early phase and is important to point out various mode of onset among CIDP.

Adult↗
PubMed1990

Dielectric study on hydration of B-, A-, and Z-DNA.

Dielectric relaxation peak due to bound water was found around 100 MHz in poly(dG-dC).poly(dG-dC) and calf thymus DNA in water-ethanol mixtures with NaCl buffer. Relaxation time and strength show a transition for poly(dG-dC).poly(dG-dC) at an ethanol composition Cw = 0.45 (w/w) where the structural transition from B- to Z-DNA takes place. It has been suggested that the transition is caused by removal of the bound water molecules preferentially from the phosphate groups. If the bound water molecules are removed equally from the phosphate groups and the grooves, the structural transition from B to A takes place. By analogy with hydration of tropocollagen, it was found that 19 water molecules per one nucleotide are at least necessary to keep B-DNA. Thirteen molecules are bound to A-DNA and 9 molecules to Z-DNA. Stringlike multimers are proposed as available structures of the bound water.

Animals↗
PubMed1990

Arteriovenous malformation at the cervicomedullary junction: a case report with magnetic resonance imaging.

A rare case of arteriovenous malformation at the cervicomedullary junction is reported. A 72-year-old man developed symptoms of total transection of the upper cervical cord without evidence of subarachnoid hemorrhage. The arteriovenous malformation had an intramedullary nidus with an aneurysmal dilatation at the C-1 level. This lesion was diagnosed by magnetic resonance imaging and confirmed at autopsy. The neurological symptoms may have been due to compression of the spinal cord by the intramedullary lesion, followed by degeneration and necrosis. The usefulness of magnetic resonance imaging in the neuroradiological diagnosis is particularly emphasized.

Aged↗
PubMed1990

Ruptured aneurysm at the origin of the accessory middle cerebral artery: case report.

The accessory middle cerebral artery is a rare vascular anomaly of the brain. We describe a case of a ruptured aneurysm at the junction of the accessory middle cerebral artery and the horizontal portion of the anterior cerebral artery. The lesion was demonstrated by angiography and confirmed at surgery. No perforating arteries arising from this accessory artery were found. There have been only four previous reports of aneurysms located at the origin of the accessory middle cerebral artery. The relevant literature is briefly reviewed.

Aged↗
PubMed1990

Magnetic resonance imaging of Chiari malformations.

The authors describe the features of magnetic resonance (MR) images of Chiari type I and II malformations and present four illustrative cases. Downward displacement of the posterior fossa was more pronounced with type II than type I. A variety of intracranial anomalies were associated with the Chiari type II malformation, whereas type I was mainly associated with syringomyelia and craniovertebral changes. MR imaging is useful in the diagnosis of intracranial anomalies and those situated at the craniovertebral junction, including Chiari malformations.

Adult↗
PubMed1990

[Effect of rhG-CSF in the treatment of multiple hepatic abscesses in chronic granulomatous disease].

A 19-year-old male was diagnosed as having chronic granulomatous disease (CGD) based on negative NBT reduction in January, 1988. He was admitted with a chief complaint of high fever in November, 1988. As abdominal echogram and CT scan established a diagnosis of multiple hepatic abscesses, he was treated with various kinds of antibiotics. Since the therapy was ineffective, the number of circulating neutrophils was decreased, and the abscesses further grew, intravenous drip infusion of rhG-CSF 100 micrograms was initiated in addition to several antibiotics (sulfamethoxazole-trimethoprim, rifampicin, isoniazide, etc). At day 3 on rhG-CSF, the fever began to resolve and on day 15 the body temperature fell below 37 degrees C. The hepatic abscesses also tended to decrease in size and the CT scan performed 2 months later (March 17), disclosed only calcification in the liver. The neutrophil function test indicated that superoxide anion (O2-) and hydrogen peroxide (H2O2) production was slightly increased during rhG-CSF therapy. Combination therapy with rhG-CSF and potent antibiotics showed a favorable therapeutic effect on CGD complicated by multiple hepatic abscesses as a fatal infection.

Adult↗
PubMed1990

Changes of brainstem auditory evoked responses (BAERs) in a brain stem ischemic model using embolization technique in cats, a preliminary study.

In order to evaluate brain stem dysfunction related to ischemic process, the authors monitored the Brainstem Auditory Evoked Responses (BAERs) with time in a brain stem ischemic model. 19 adult mongrel cats were divided into two groups: embolization (n = 14) and sham operated control (n = 5). Embolization was done by injecting cylindrical silicone embolus to the right vertebral artery. Each successful embolization of the basilar artery was then confirmed by vertebral angiography. BAERs were monitored before embolization and then 5-10 min, 15 min, 30 min, 60 min, 3 hr and 6 hr after embolization. The presence of ischemic lesion caused by embolization was confirmed by injecting 2% Evans blue solution 30 min before sacrificing the animals. Leakage of the dye was observed. In embolized animals, significant (Student t test, p less than 0.05) delay of interpeak latencies of waves 1-3, 3-5, and 1-5 was observed 15 min after embolization. This delay became more significant (p less than 0.01) 30 min after embolization. These results provide evidence for the usefulness of BAERs monitoring which can be used to complement other diagnostic methods for patients with vertebrobasilar insufficiency and/or infarction.

Animals↗
PubMed1990

[Experimental study on the difference of ischemic threshold between cerebral cortex and thalamus with middle latency auditory evoked potentials].

Middle latency auditory evoked potentials (ML-AEPs) have not yet been established as a device of assessing neurological events because their origins have not been definitely identified. In this study, we assessed the neurological usefulness of MLA-EPs through experimental approach using canine models of acute ischemia localized within the cerebral cortex or thalamus. Two types of localized cerebral ischemia were produced in mongrel dogs by clipping of major cerebral arteries and inducing of hypotension; they were, unilateral cortical ischemia involving the right primary auditory area (group A) and unilateral thalamic ischemia involving the right medial geniculate body (group B). Using these two ischemia models, auditory evoked potentials (AEPs) were intracranially and extracranially recorded in addition to the measurement of local cerebral blood flow (1-CBF). Prior to the induction of ischemia, it was confirmed that positive waves with a latency of 20 ms (P20) were evoked in the bilateral primary auditory areas by sound stimulation (90 dB 5 Hz click) given to the ear contralateral to the planned ischemic side in both groups. The right P20 disappeared when the 1-CBF in the right primary auditory area decreased below the ischemic flow threshold of synaptic transmission failure, approximately 18 ml/100 g/min, in group A, and when the 1-CBF in the right medial geniculate body decreased below the threshold, 10 ml/100 g/min, in group B.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1990

[Somatosensory evoked potentials in patients with hypoxic coma--correlation with neurologic prognosis].

Somatosensory evoked potentials to median nerve stimulations were recorded in 21 patients with hypoxic coma within 24 hours from the onset. According to the neurologic prognosis, the patients were classified into 4 groups, such as I, complete recovery (5 patients), II, partial recovery (3 patients), III, vegetable state (8 patients), IV, brain death (5 patients). Measurements performed include central conduction time (N13-N20 interpeak latency) and amplitude ratio between N20 and P25. As N20 and P25 disappeared in 3 of 8 vegetable patients and all of brain death patients, disappearance of these waves indicates poor neurologic prognosis. Central conduction time showed no significant difference. Amplitude ratio between N20 and P25 (P25/N20) revealed significant decrease in vegetative patients for normal control subjects, complete recovery and partial recovery patients (p less than 0.05). Measurement of this ratio in early phase is useful to predict neurologic outcome in patients with hypoxic coma.

Adolescent↗
PubMed1990

An investigation of vascular anatomy and microvascular architecture of the brainstem in cats.

The vascular anatomy and microvascular architecture of the vertebrobasilar system, especially within the brainstem, was investigated in cats. The main branches of the basilar artery were observed and the inner diameters of these vessels were measured on vertebral angiograms. The three-dimensional microvascular architecture was constructed using molded vascular models. The arterial anastomoses between the arteries inside the brainstem were studied using contact microangiograms. The paramedian branch penetrated into the brainstem in a retrograde fashion from the cranial basilar artery, and in an anterograde fashion from the caudal basilar artery. Arterial anastomoses were noted between the circumferential arteries. The frequency of arterial anastomoses was higher and diameters of the anastomotic vessels were larger in the ventrolateral region of the brainstem than in the ventromedial region. Regarding the perforating arteries, the arterial anastomoses were present outside the brainstem. No arterial anastomoses were found inside the brainstem.

Angiography↗
PubMed1990

[Hypertensive recurrent intracerebral hemorrhage accompanied with orthostatic hypotension and labile hypertension].

Authors reported a case of recurrent intracerebral hemorrhage accompanied by severe orthostatic hypotension. A 51-year-old women had recurrent intracerebral hemorrhage 3 times during a period of 2 years. The first and third hemorrhages were located in the right putaminal region, and the second hemorrhage in the left thalamic region. Cerebral angiography revealed neither evidence of vascular malformation nor that of tumor vessels. At the third admission, she became unconscious for three hours after admission, and emergent fronto-temporal craniotomy was performed. Light microscopic histological investigation with congo-red stain demonstrated the absence of cerebral amyloid angiopathy. Laboratory examination revealed no hemorrhagic diathesis. During hospitalization, She complained of dizziness in the standing position. When systolic blood pressure fell from 140 mmHg in the supine position to less than 80 mmHg in the standing position, she became unconscious. Her blood pressure was very labile with orthostatic changes and her systolic blood pressure was also very labile without orthostatic changes, changing from 108 mmHg to 218 mmHg. Severe orthostatic hypotension and labile hypertension made the medical control of hypertension difficult. In conclusion, both severe orthostatic hypotension and labile hypertension were risk factors of recurrence of intracerebral hemorrhage.

Cerebral Angiography↗
PubMed1990

[A comparison of the functional vulnerability of the cerebral cortex and thalamus to acute ischemia].

Using cerebral cortical and thalamic ischemia models produced in mongrel dogs, the reversibility of short-latency somatosensory-evoked potentials (SSEPs) and the effects of ischemic brain edema on reversibility were compared. The mean systemic blood pressure (MSBP) of animals was reduced by exsanguination until cortical SSEPs disappeared, and was held constant at that level. The MSBP was recovered by autogenous blood transfusion at 30 minutes (subgroup A), 60 minutes (subgroup B) and 90 minutes (subgroup C) after SSEP disappearance in the cortical ischemia group; and at 15 minutes (subgroup D) and 30 minutes (subgroup E) after SSEP disappearance in the thalamic ischemia group. Local cerebral blood flows (lCBF) were measured and SSEPs were monitored serially up to 2 hours after blood transfusion. At the end of measurement, the leakage of Evans blue was evaluated and brain tissue water content was measured. Cortical SSEPs disappeared when lCBF in the right cerebral cortex, measured by hydrogen clearance method decreased to 18.4 +/- 5.4 ml/100 g/min (mean +/- SD) and neuronal transmission failure in thalamus occurred when thalamic blood flow decreased to 10.0 +/- 3.3 ml/100 g/min. After blood transfusion. SSEP reappeared in all 12 animals in subgroup A, but did not appear in 2 of 9 animals in subgroup B and in all of 7 animals in subgroup C.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

Cavernous angioma of the cerebellum--case report.

Computed tomography (CT) allows earlier diagnosis of intracranial cavernous angioma than was formerly possible. However, cerebellar lesions are uncommon. Cerebellar cavernous angioma with hemorrhage was diagnosed in a 54-year-old male who suddenly developed nausea and vomiting, then declined over the following week and developed ataxia and nystagmus. Blood pressure was normal, and he had no history of hypertension or hemorrhagic diathesis. Precontrast CT revealed an irregularly-shaped, hyperdense lesion in the left cerebellum and an associated hematoma. Injection of contrast medium did not significantly enhance the lesion. Vertebral angiography demonstrated only an avascular mass in the cerebellum. A semiliquid hematoma was evacuated and a vascular nodule was removed from the posterior wall of the hematoma cavity. The histopathological diagnosis was cavernous angioma. Nine sufficiently documented reports of cerebellar cavernous angioma are reviewed and the clinical and radiological features of these lesions are discussed.

Cerebellar Diseases↗
PubMed1989

Eaton-lambert syndrome associated with pituitary apoplexy--a case report.

A case of Eaton-Lambert syndrome associated with pituitary apoplexy is presented. It is thought to be the first reported case. The clinical features, electrophysiological findings and effects and side effects of therapeutic drugs are noted. Endocrinological dysfunctions are discussed in relation to pituitary disorder.

Bronchial Neoplasms↗
PubMed1989

[Diffuse abdominal uptake of 67Ga-citrate; report of three cases].

Three cases, two peritoneal lymphomatosis and one tuberculous peritonitis, which showed diffuse abdominal uptake of 67Ga-citrate, were reported. 67Ga scan should be indicated for patients suspected of malignancy or inflammation with a lack of localized symptoms and signs in the abdomen. 67Ga-citrate scan also can give notable information on the evaluation of therapeutic response in those patients.

Adult↗