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Biomedical subjects

A Teramoto

Publications and source records attributed to A Teramoto.

At least 73 records · Page 4Linked to original sources
PubMed2000

Pituitary stone--case report.

A 50-year-old male with acromegalic features presented with a pituitary stone in a growth hormone-secreting adenoma. Endocrinological examination showed "low growth hormone acromegaly." The serum growth hormone level responded to the thyrotropin-releasing hormone test and was not suppressed by oral glucose loading. Neuroimaging revealed an adenoma including a large calcification (pituitary stone) located in the right lateral wing. The adenoma with stone was totally removed by transsphenoidal surgery. The patient regained almost normal response of serum growth hormone. Histological examination showed the stone was composed of thick calcification surrounded by necrotic adenoma tissue and chronic hemorrhage. Large intratumoral pituitary stone is very rare, although calcification is sometimes observed in the adenoma capsule. The long history of this disease and previous apoplexy within the tumor may have caused the pituitary stone in this patient.

Acromegaly↗
PubMed2000

Hemangioblastomas with blood supply from the dural arteries--two case reports.

Hemangioblastomas are benign vascular tumors that often occur in the cerebellum, and are located near the pia mater. The blood supply is usually received through the pia mater, and rarely through the external carotid artery. The present cases of hemangioblastoma received blood supply from the external carotid artery (occipital artery) and a branch of the internal carotid artery (carotico-tympanic artery or artery of Bernasconi Cassinari) through the dural branches. The dural arteries were not the main feeders in either case, but preoperative embolization of the occipital artery contributed to minimum bleeding during the operation in one case. Incomplete resection of hemangioblastoma is related to multicentricity of the tumors, small mural nodules, or brain stem involvement. Angiography is valuable for demonstrating arterial supply to small or multiple mural nodules. Conventional angiography is necessary for investigation of the external carotid artery branches.

Aged↗
PubMed2000

Long-term surgical outcome in 16 patients with thyrotropin pituitary adenoma.

OBJECT: Thyrotropin-secreting pituitary adenomas are rare lesions of the endocrinological system. Although introduction of a hypersensitive radioimmunoassay for thyrotropin enables the recognition of inappropriate secretion of this hormone, the aforementioned lesions remain uncommon and unfamiliar to most neurosurgeons. It has been reported previously that surgical cure of thyrotropin-secreting adenomas is more difficult than in other functional adenomas because of the large size and invasive features of the former. However, the long-term outcome after surgery has not been well documented. The authors report on a surgical series of 16 patients with thyrotropin adenoma and the results of long-term follow up. METHODS: Sixteen patients ages 23 to 62 years (12 women and four men) underwent transsphenoidal removal of thyrotropin adenomas between 1983 and 1999. These patients had the syndrome of inappropriate thyrotropin secretion (SITS) with pituitary mass lesions. Four of the patients had undergone previous subtotal thyroidectomy and/or radioiodine thyroid ablation, and 11 had been treated with antithyroid medication. Radiological investigations demonstrated macroadenomas in 14 patients, and 10 of those had cavernous sinus invasion. Surgical findings showed unusually fibrous and firm tumors in 13 (81.2%) of 16 patients. Preoperative octreotide administration was revealed to be effective for serum thyrotropin reduction as well as tumor shrinkage. Transsphenoidal surgery was performed with no morbidity resulting. Surgical remission was achieved in 10 (62.5%) of 16 patients, and total remission was achieved in 14 patients (87.5%) with a combination of additional radiation or medical therapy. In the other two patients, SITS persisted because of tumor rests in the cavernous sinus. Therefore, radiation and/or antithyroid therapy was administered. In the mean follow-up period of 7.5 years (range 11 months-15.8 years), no recurrence of tumor was observed on magnetic resonance images, whereas recurrence of SITS was found in two patients with no tumor regrowth. In addition, coexistent primary hyperthyroidism was found in two other patients despite remission of SITS after surgery. CONCLUSIONS: Transsphenoidal surgery can achieve a good long-term outcome in patients with thyrotropin-secreting pituitary adenomas if surgery is performed before these become larger, invasive tumors. In the authors' experience, thyrotropin-secreting adenomas are fibrous and firm, which makes it difficult to achieve surgical remission. In addition, even satisfactory resection of the tumor sometimes results in recurrence of SITS or hyperthyroid symptoms due to coexistent primary hyperthyroidism. It is emphasized that a careful follow-up review is necessary after surgery, especially in patients with a long preoperative history of hyperthyroidism.

Adenoma↗
PubMed2000

Ependymal cyst producing alpha-fetoprotein. Case report.

This 17-year-old man was admitted to the hospital due to progressive headache and diplopia. Neuroradiological studies revealed a cystic mass in the pineal region without a parenchymal lesion. In addition, serum alpha-fetoprotein (AFP) levels were elevated. A cyst-to-third-ventricle and cistern fenestration was performed, but the cyst enlarged 3 months after the first operation. In the second operation, subtotal resection of the cyst was performed. The AFP level in the cyst fluid was very high preoperatively but was decreased postoperatively. The patient was discharged with no neurological deficit. Pathological examination of resected tissue showed a single layer of cuboidal cells that resembled an ependymal structure. The cells were immunoreactive for AFP immunostain, which indicated AFP production from these cells.

Adolescent↗
PubMed2000

Spontaneous regression of a germinoma in the pineal body after placement of a ventriculoperitoneal shunt.

The authors report a case in which a germinoma in the pineal body displayed spontaneous regression after placement of a ventriculoperitoneal (VP) shunt. Spontaneous regression of malignant tumors is extremely rare, occurring in only one of 60,000 to 100,000 patients. Although in rare cases spontaneous regression is known to occur in patients with testicular seminomas, only one case of spontaneous regression of a primary pineal germinoma has so far been reported. In the present case a 17-year-old man presented with headache. A tumor in the pineal body and acute hydrocephalus were revealed by head computerized tomography (CT) and magnetic resonance (MR) imaging, and VP shunt placement was performed. Computerized tomography scanning of the head was performed four times during a 2-week period following the operation, and the patient was temporarily discharged to return to school. At the time of discharge, CT scanning demonstrated no change in the size of the tumor. Two months later, the patient was readmitted to the hospital to undergo surgery. At that time, head MR imaging revealed regression of the tumor. The pathological diagnosis of the lesion was germinoma. The patient underwent three courses of chemotherapy, during which carboplatin and etoposide were administered, in addition to a 24-Gy dose of radiotherapy. No manifestations of nerve impairment were noticed, and the patient was observed on an outpatient basis. The authors think that the factors involved in tumor regression included the effects of the VP shunt, the effects of radiation absorbed during head CT scanning, and the role of the patient's own immune response. However, no conclusion has been reached concerning the actual cause.

Adolescent↗
PubMed2000

[An ultrasonic study of the relationship between extracranial carotid atherosclerosis and intracerebral hemorrhage].

We have evaluated the relationship between carotid atherosclerotic change and intracerebral hemorrhage patients. Forty-eight patients with intracerebral hemorrhage treated at our institution were included in this study. Their ages ranged from 38 to 86 years old (average: 61.5 years). There were 28 cases of putaminal hemorrhage and 20 cases of thalamic hemorrhage. Evacuation of hematoma or ventricle drainage was performed in 18 cases within 3 days after the onset of symptoms. The outcome in these cases was that 40 patients survived and 8 patients died. Carotid atherosclerosis was evaluated by B mode-ultrasonography. The severity of carotid atherosclerosis was assessed by using two indicators; incidence of carotid atherosclerosis and maximum percentage diameter of the stenosis. Carotid atherosclerosis on B mode-ultrasonography was detected more frequently in patients with thalamic hemorrhage (84.2%) than in those with putaminal hemorrhage (51.7%). Maximum percentage stenosis of thalamic hemorrhage (17.2 +/- 15.2%) was higher than maximum percentage stenosis of putaminal hemorrhage (6.4 +/- 9.7%). In conclusion, carotid atherosclerosis was an effective indicator of not only ischemical cerebrovascular disease but also of intracerebral hemorrhage.

Adult↗
PubMed2000

[Metabolic acidosis and ketone body in severely head-injured patients].

Increase of ketone body concentration in plasma is induced by various factors such as onset of diabetes. Secretion of excessive stress hormone including catecholamine is responsible for stimulation of lipolysis which increases plasma ketone body concentration. Catecholamine levels reflect the severity of the neurologic insult, so this is a basis for the use of catecholamine measurements as a physiological marker of patient outcome. Twenty-seven patients with severe head injury and twenty-five healthy volunteers were enrolled in this study, but patients with diabetes or liver dysfunction were excluded. The patients with severe head injury consisted of 19 with focal injury and 8 with diffuse injury. The outcome was as follows; 14 patients died and 13 patients survived. We collected arterial blood samples as promptly as possible after onset of severe head injury and measured the following: 1, base excess; 2, beta-hydroxybutyrate; 3, acetoacetate; 4, lactate; 5, epinephrine; 6, norepinephrine. The ketone body (beta-hydroxybutyrate + acetoacetate) concentration in plasma was significantly elevated in patients with severe head injury. The increment of beta-hydroxybutyrate levels was greater than that of acetoacetate levels, resulting decreased arterial ketone body ratio (AKBR; acetoacetate/beta-hydroxybutyrate). We demonstrated that plasma ketone body concentrations were elevated and the AKBR decreased in severe head-injured patients. Elevation of catecholamine has been reported as a stress reaction in severe head injury. Catecholamine is most potent in stimulating lipolysis, and ketogenesis. Therefore, the ketonemia observed in severe head injury is most likely to be induced by elevation of catecholamine levels. The degree of ketonemia may be an index of the severity of severe head injury.

3-Hydroxybutyric Acid↗
PubMed2000

[The usefulness of fluconazole administration and beta-D-glucan measurement in neurosurgical patients with deep-seated mycosis].

The diagnostic usefulness of beta-D-glucan values and the efficacy of flconazole (FLCZ) were investigated in 20 patients with deep-seated mycosis treated in our neurosurgical department from Oct 1, 1997 to May 31, 1998. The diagnosis of deep-seated mycosis was carried out using mycological and serological methods. When the serological beta-D-glucan value was above 10 pg/ml, the patient was considered to have deep-seated mycosis. In 13 patients (65%), the definite diagnosis of deep-seated mycosis was established by culture. In 7 patients, diagnosis based on serological examination alone was false positive or false negative. FLCZ 200 or 400 mg per day was administered for 10 days. Three patients were administered 200 mg/day FLCZ for another 10 days. No side effect of FLCZ was noticed among these patients. Three of 13 patients (23%) in whom fungi were isolated became fungi negative after FLCZ administration. The mean beta-D-glucan values before and after the administration of FLCZ were 36.37 mg/ml and 13.75 mg/ml, respectively. The beta-D-glucan values before and after the administration of FLCZ were significantly correlated with statistics (Student's t-test; p < 0.001). It was concluded that FLCZ was useful, and that beta-D-glucan values generally reflected the therapeutic effect of FLCZ. In contrast to the mycological culture tests that provided only a low detection rate, beta-D-glucan values were useful not only as a diagnostic means but also as a means to evaluate the efficacy of FLCZ treatment.

Adult↗
PubMed2000

[A case of neurocysticercosis presenting as focal seizure].

In Japan neurocysticercosis is a rare disease. We report a case of neurocysticercosis with a review of the literature. A 29-year-old man presented focal seizure on the left side. Physical and neurological findings on admission were unremarkable. CT and MRI showed a mass with ring-like enhancement and perifocal edema in the right frontal lobe, as well as multiple small masses with calcification. The main mass measuring 8 mm in diameter, was suspected as the eliptogenic focus, and was totally removed via the transcortical approach. Postsurgically seizures did not recur, and histological examination of the mass confirmed a cysticercus. A therapeutic course of albendazole and praziquantel administered postsurgically was effective for the multiple intraparenchymal masses.

Adult↗
PubMed2000

[A case of urinary retention secondary to aseptic meningitis].

A 46-year-old male was admitted to our hospital with headache, high fever and subsequent consciousness disturbance. Spinal fluid examination intimated aseptic meningitis. Not only these symptoms but bladder dysfunction was presented. The patient was treated with conservative therapy and bladder dysfunction was resolved a month and a half later. We report a case of urinary retention secondary to aseptic meningitis and review the clinical presentation and treatment.

Acyclovir↗
PubMed1999

The Macromolecular Route to Chiral Amplification.

Cooperative phenomena, described by one-dimensional statistical physical methods, are observed between the enantiomeric characteristics of monomeric materials and the polymers they produce. The effect of minute energies associated with this amplified chirality, although currently not interpretable, can be easily measured. Nonlinear relationships between enantiomeric excess or enantiomeric content and polymer properties may offer the possibility of developing chiral catalysts and chiral chromatographic materials in which the burden of large enantiomeric excess or content may be considerably alleviated. New approaches to information and sensor technology may become possible.

Journal Article↗
PubMed1999

Analysis of the MEN1 gene in sporadic pituitary adenomas from Japanese patients.

An autosomal-dominant syndrome known as multiple endocrine neoplasia type 1 (MEN1) is characterized by tumors in parathyroid glands, pancreatic endocrine tissues and the anterior pituitary gland. The predisposing gene was identified at 11q13 when germline mutations in the MEN1 gene were detected in affected pedigrees. To investigate a possible role of this gene in tumorigenesis of non-familial pituitary adenomas, we examined 24 sporadic tumors from Japanese patients for loss of heterozygosity (LOH) at the 11q13 region and for somatic mutations in the entire coding region and exon-intron boundaries of MEN1. Although three common sequence variants were detected, none of the tumors exhibited either LOH or somatic mutations of this gene. Our results indicate that inherited and sporadic forms of pituitary adenomas are different in terms of the genetic events that contribute to their development, and that other loci associated with pituitary neoplasia must still be sought.

Adenoma↗
PubMed1999

Mutations of the MEN1 tumor suppressor gene in sporadic pituitary tumors.

Pituitary adenoma is a common neoplasm accounting for 10% of all intracranial tumors. Although the molecular mechanisms underlying the formation of these tumors are largely unknown, a small portion of pituitary adenomas occur in patients with the multiple endocrine neoplasia syndrome type 1 (MEN 1). Although two groups in the United States and Canada have recently reported that sporadic pituitary adenomas very rarely harbor a somatic mutation in the MEN1, MEN1 gene mutation analysis in sporadic pituitary adenomas has not yet been carried out in the Japanese population. To elucidate the potential etiological role of the MEN1 gene in the formation of sporadic pituitary adenomas in Japan, we investigated 40 Japanese patients with sporadic pituitary adenomas (16 hormone-secreting and 24 nonsecreting tumors) for MEN1 gene mutation. Polymerase chain reaction-single-stranded DNA conformation polymorphism analysis and sequencing demonstrated a somatic mutation in the MEN1 gene in only one of the 40 tumors, a prolactinoma, which had a 1-bp deletion in the coding sequence of exon 2. The data suggest that somatic mutations in the MEN1 gene do not play a prominent role in the pathogenesis of sporadic pituitary adenomas.

Adenoma↗
PubMed1999

Frequent allelic loss at the TOC locus on 17q25.1 in primary breast cancers.

Sporadic breast cancers often show allelic losses on the long arm of chromosome 17. Since the BRCA1 gene lies at 17q21.1 and the TOC locus, associated with esophageal cancer, lies at 17q25.1, either gene could be the target of those losses. We examined both loci in 178 primary breast cancers, using microsatellite markers covering the relevant regions of 17q, and observed allelic losses in 97 tumors (55%). Losses were most frequent at markers around the TOC locus (48% at D7S1839 and 43% at D17S1603), where we identified a distinct commonly deleted region within a I -cM interval. Another larger, separate commonly deleted region including the BRCA1 gene was also identified, which exhibited 45% of allelic loss (at D17S934). Allelic loss on 17q was more frequent in tumors of the solid-tubular histologic type (P = 0.0129) and in estrogen-negative and progesterone-negative tumors (P = 0.0281 and 0.0196, respectively). The results indicated that BRCA1 and TOC are independent targets of allelic loss on 17q in primary breast cancers, and that inactivation of the TOC locus in particular may play an important role in the genesis of sporadic breast tumors.

BRCA1 Protein↗
PubMed1999

Expression of Ptx1 in the adult rat pituitary glands and pituitary cell lines: hormone-secreting cells and folliculo-stellate cells.

The pituitary homeobox1 gene (Ptx1) was initially identified as encoding a pituitary-restricted transcription factor for the proopiomelanocortin (POMC) gene. In order to elucidate the expression pattern of the Ptx1 protein, we investigated the localization of the protein in adult rat pituitary gland and in various pituitary cell lines. We produced an antibody specific for Ptxl protein, and confirmed its specificity by Western blot analysis. Immunohistochemically, many nuclei in the anterior pituitary cells as well as in the intermediate cells were positive for Ptxl staining with this specific antibody. Immunohistochemical double staining revealed the presence of Ptx1 not only in all types of hormone-secreting cells but also in some folliculo-stellate (FS) cells. Furthermore, the expression of Ptx1 mRNA was confirmed in various pituitary cell lines and in the FS cell line by using the reverse transcriptase-polymerase chain reaction (RT-PCR) method. Our studies indicated that Ptxl may not only play a role as a basic transcriptional factor for production of various hormones, but may also play some important role(s) in FS cells. Possible synergistic actions with other factors remain to be investigated. The novel finding of Ptx1 in FS cells is of particular interest, and may suggest that FS cells and hormone-secreting cells are derived from a common cellular ancestor.

Animals↗
PubMed1999

Cavernous hemangioma of the skull in a neonate.

Cavernous hemangiomas rarely occur in the calvarium and most commonly present in middle-age. Although a congenital vascular disorder can theoretically cause a diploic lesion in any age group, a calvarial cavernous hemangioma has not been reported in newborn. A 4-month-old male infant presented with a large left parietal mass that had been present since birth. Total resection was performed. Pathological examination revealed a cavernous hemangioma developing within the diploic space adjacent to prior hemorrhages. Surgery was performed in this case because of the size and persistence of the lesion. Removal of tumors of a benign nature from the calvarium can be done safely. Cavernous hemangioma of the skull in a neonate should be considered as one of the differential diagnoses in the case of suspected ossified cephalohematoma.

Hemangioma, Cavernous↗
PubMed1999

Effect of niravoline (RU51599), a kappa-opioid receptor agonist, on tumour-origin brain oedema.

Niravoline is a selective kappa-opioid receptor agonist. Its effect on tumour-origin brain oedema was investigated in a brain tumour model created by implantation of C6 glioma cells into the brain of Wistar rats. Five weeks after the tumour cell implantation, niravoline was administered i.v. at 1 mg/kg, a total of four times at one-hour intervals. In the control group (i.e., saline or vehicle-treated rats), this brain tumour model was found to result in a statistically significant increase in the water content in selected brain regions except for the frontal region, the tumour-containing region and the region surrounding the tumour-containing region. Administration of niravoline inhibited the increase in the water content in the brain regions remote from the tumour.

Animals↗