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Biomedical subjects

T Shima

Publications and source records attributed to T Shima.

At least 181 records · Page 10Linked to original sources

Cystic cavernous hemangioma in the frontal lobe in an infant--case report.

A 4-month-old infant was hospitalized following a generalized convulsion. Computed tomography showed a lesion of heterogeneous high density and a large low-density area in the right frontal lobe. At surgery, an angiomatous tumor was found within a large cyst containing bloody fluid. Histopathological diagnosis was a cavernous hemangioma. Only eight other cavernous hemangiomas in infants have been reported. The characteristic clinical features and computed tomographic findings of these cases are discussed.

Brain Neoplasms↗

Increased calcium levels alter cellular and molecular events in wound healing.

Surgical morbidity is dictated directly by wound healing. We have studied the effects of elevated calcium levels using cultured keratinocytes in vitro on two of the rate-limiting steps of wound healing, chemotaxis (directed migration) and adhesion. We found that the increased calcium (10 mmol/L) significantly inhibited both keratinocyte chemotaxis and adhesion (p less than 0.05). The calcium effect on adhesion could be partially reversed by pretreatment with the calcium channel blocker verapamil. Based on these data, an animal model was formulated in which topical calcium (5 mmol/L/day) was added to linear incision wounds. This resulted in significantly (p less than 0.05) delayed wound contraction characteristic of a chronic or impaired wound. Wound contraction depends on the presence of fibroblasts that synthesize collagen. The chronic wound was characterized by increased collagenase activity (p less than 0.05) but little alteration in collagen I synthesis. The addition of verapamil to these chronic wounds resulted in improved wound closure. These studies define the molecular and cellular events occurring as a result of the addition of elevated levels of calcium both in vitro and in vivo. Calcium may play a key role in the pathogenesis of chronic wounds.

Animals↗

[Primary interhemispheric subdural abscess: report of a case].

We reported a rare case of primary interhemispheric subdural abscess. Twenty-three cases of this pathological condition have been reviewed. In those reports, however, findings of magnetic resonance imaging (MRI) were not referred to. In this report, MRI findings in this pathological condition, in addition to X-ray computed tomography (CT), is mentioned. A 22-year-old man, who had suffered from headache and vomiting for 2 weeks, suddenly became drowsy and left-hemiparetic. The X-ray CT scan on admission showed a well-circumscribed low density area in contact with the falx in the right parieto-occipital region. This lesion had so called "ring enhancement". MRI in the sagittal view revealed that, along the falx, the long T1 and T2 areas extended from the right cerebellar tentorium to the right frontal region. The operation demonstrated the capsular formation of the abscess. After pus aspiration, continuous drainage was performed from the cavity of the abscess. The patient fully recovered postoperatively. In the diagnosis of interhemispheric subdural abscess, it is said that conventional X-ray CT sufficiently reveals the quality of the lesion, the precise site, and the anatomical relation to the surrounding edema. In our case, MRI was able to confirm the diagnosis made by the X-ray CT. Furthermore, MRI was thought to be superior to the X-ray CT in the evaluation of the extension of the abscess and in the delineation of the surrounding edema. Combined use of X-ray CT and MRI in cases of interhemispheric abscess was considered to make the diagnosis more precise in both qualitative and quantitative aspects.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

[Anesthesia for a patient with HELLP syndrome].

A case of 30 year-old female with HELLP syndrome, who had undergone emergency caesarean section under general anesthesia, was reported. HELLP syndrome is characterized by hemolysis, liver dysfunction and thrombocytopenia, besides symptoms of severe toxemia of pregnancy. After an awake orotracheal intubation, anesthesia was maintained with nitrous oxide, oxygen and muscle relaxant. Blood pressure was controlled with intravenous administration of nitroglycerin. Though the eclampsia was recognized several times during and after the operation, the patient and her baby had no complication nor sequela on their discharge. The key in the anesthetic management of caesarean section in a patient with HELLP syndrome is to control hypertension and eclampsia, to consider the presence of liver and kidney dysfunctions, and to improve anemia and bleeding tendency.

Adult↗

[Experimental focal cerebral ischemia produced by embolization with silicone cylinder in normotensive (NTR) and spontaneously hypertensive rats (SHR): comparison of neurological and pathological findings].

A focal cerebral ischemic model was produced by occlusion of the intracranial main cerebral artery with a silicone cylinder in normotensive (NTR) and spontaneously hypertensive rats (SHR). Main cerebral artery could be successfully occluded in approximately 90%. The most frequent embolized site was the distal part of the internal cerebral artery (ICb) and less frequently the horizontal segment of the anterior cerebral artery (Al). Mortality rate of NTR with ICb occlusion (NTR-ICb) was 43% at 72 hours after embolization and that of SHR with ICb occlusion (SHR-ICb) was 67% at 24 hours after embolization. NTR-ICb showed neurological signs (i.e. circling movement, hemiparesis, poor response to pain stimuli) and histologically, showed infarction in the deep cerebral structures (i.e. thalamus, hypothalamus, hippocampus, and internal capsule) accompanied with mild disruption of blood-brain barrier (BBB). SHR-ICb showed more serious neurological signs and more severe cerebral infarction in the deep cerebral structures with severe disruption of BBB. In SHR-ICb, ischemic cerebral edema was more prominent which may deteriorate symptoms and pathological findings compared to NTR-ICb. This embolization model is proposed to be useful for studying the pathophysiology of focal cerebral ischemia, especially, early ischemic edema.

Animals↗

[Comparison of two dimensional and three dimensional CBF measurements in stroke patients].

The purpose of this study is to compare the detectability of the reduction in cerebral blood flow (CBF) using the two versus the three dimensional technique of CBF measurement. Both techniques were simultaneously carried out 85 times on 52 stroke patients. In the two dimensional technique, CBF was measured by the Xe-133 inhalation method and the value was calculated by the initial slope index. In the three dimensional technique, CBF was measured by single photon emission CT with Xe-133 inhalation method. CBF reduction was studied in the middle cerebral artery (MCA) territory on a CBF map in both techniques. Additionally, mean CBF was also calculated for the same territory. On the CBF map, the CBF reduction was shown in 25 of 85 measurements with the two dimensional technique and in 41 of 85 with the three dimensional technique. In comparing the imagings of both techniques, the CBF reduction seen extensively along the cortical surface and in the entire MCA territory with the three dimensional technique was also detected with the two dimensional technique. However, focal CBF reduction observed at the cortical surface and in the deep cerebral tissue with the three dimensional technique was not detected with the two dimensional technique. In order to evaluate both techniques quantitatively, we calculated the ratio of the mean CBF difference between the MCA territories of both hemispheres to mean CBF in the non-affected MCA territory. This ratio represented the asymmetry index. Firstly, the relationship between asymmetry index and the imaging of CBF reduction on the CBF map was studied.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Inhalation↗

[A case of anaphylactoid reactions to lactated Ringer's solution with 5% maltose].

A 27-years-old man was admitted for correction of nasal fracture. He presented with circulatory collapse and generalised erythema on induction of general anesthesia and during preparation of intradermal test for identifying the offending agent. As both of these responses occurred during intravenous infusion of lactated Ringer's solution with 5% maltose, anaphylactoid responses to this intravenous solution were strongly suspected.

Adult↗

[Intraoperative monitoring of cerebral function and carotid hemodynamics during carotid endarterectomy].

The authors investigated the hemodynamics and monitored the cerebral function to perform the carotid endarterectomy (CEA) safely. The hemodynamics were investigated by measurements of carotid arterial blood flow by an electromagnetic flow meter before and after CEA. And a doppler flow meter applied directly to the carotid arteries to analyze the flow parameters such as peak frequencies (PF), mean frequencies (MF), mode frequencies (Mo F) and % window. We used routinely our specially designed shunt system during surgery, by which stump pressure of the ICA could be measured easily. The cerebral function was evaluated by the amplitude of N20-P25 component of somatosensory evoked potential (SEP). Flow parameters of doppler sounds demonstrated significant changes such as inversion of MF and Mo F, decrease in % window at the poststenotic ICA in the severe stenosis group. By these doppler sounds the extension of stenotic lesion could be detected clearly. The ICA flow showed evidently low values in patients with more than 80% stenosis, which was improved by CEA. With our specially designed T-tube shunt system, stump pressure, side pressure and direct pressure of the ICA could be monitored easily. The mean stump pressure was 52 mmHg and systemic arterial blood pressure was 99 mmHg on the average. SEP revealed evident changes during temporary occlusion in 10 out of 41 patients, which improved following the reflow with the shunt system. Mean stump pressure in the 11 patients was 33 mmHg, and that in the remaining patients were 59 mmHg on the average.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Transplantation of mucosal tissue model composed of rabbit oral mucosal cells.

Since skin grafted into the oral cavity does not differentiate into mucosa, its original characteristics remain unchanged. This may cause discomfort to patients treated with such grafted skin, due to the skin's hair follicles and keratinization. This phenomenon is controlled by subepithelial connective tissues, and is thus referred to as the Epithelio-Mesenchymal Interaction. The grafting of mucosa itself would be preferable, but this procedure is severely limited due to the scarcity of suitable tissue. Accordingly, we have recently prepared artificial mucosa in vitro, using fibroblasts and epithelial cells derived from rabbit oral mucosa and collagen gel, and transplanted it into a donor animal. This paper is the first report of a method using artificial mucosa for the reconstruction of mucosal defects.

Animals↗

Acromegaly and hyperthyroidism associated with McCune-Albright syndrome.

A 36-year-old man is described having McCune-Albright syndrome, acromegaly likely due to somatotroph hyperplasia and hyperthyroidism due to adenomatous goiter. Sexual precocity was not noted. The sella was narrow in size and no mass was seen. The decline of elevated GH by hyperglycemia and increase by GHRH-44(NH2) may support somatotroph hyperplasia, but plasma GHRH-44(NH2) levels were not elevated. A mass in the right lobe and enlargement of the left lobe of the thyroid were noted. Thyroid hormone levels in serum and thyroidal radioiodine uptake values were elevated, while TSH measurements in serum were low. The radioiodine scan showed a cold nodule in the right lobe and a hot area in the left of the thyroid. Thyroidal radioiodine was not suppressed following T3 given orally. These findings are compatible with functioning glands autonomously as the mechanism for the endocrinopathies associated with the McCune-Albright syndrome.

Acromegaly↗

Laserthermia on head and neck malignancies--experimental and clinical studies.

In recent years, remarkable progress has been made in thermotherapy. However, there is little information on localized laser hyperthermia (laserthermia) or on conventional hyperthermia technique applied to head and neck cancers. We have developed a ceramic probe to insert into tumor tissue and irradiate the Nd:YAG laser omnidirectionally. This probe can heat a spherical range of 1.5 cm to 43 degrees C. This paper concerns experimental and clinical studies on the effectiveness of laserthermia using our technique in the tumor of head and neck regions. The results obtained were as follows: histological findings and biochemical studies of arachidonic acid metabolites on normal rabbit tongue after laserthermia showed very slight effect and relatively short duration of the concomitant inflammation. The combination of laserthermia and CDDP chemotherapy was found to give a much better cytocidal effect on the tumor tissue in nude mice implanted with human thyroid cancer cells. In a clinical study on 21 cases with head and neck cancers, four cases showed complete and 13 cases showed partial remission after combined treatments of laserthermia and radiochemotherapy. Both basic experimental and clinical results have indicated a role for laserthermia in the treatment of head and neck cancer. Possible uses include the treatment of early cancer as well as advanced or recurrent cancer, where its therapeutic effect may be increased by combination with radiotherapy or chemotherapy.

Animals↗