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Biomedical subjects

H Imamura

Publications and source records attributed to H Imamura.

At least 253 records · Page 14Linked to original sources
PubMed1994

Experimental model of posttraumatic syringomyelia: the role of adhesive arachnoiditis in syrinx formation.

An experimental model was devised to elucidate the role of spinal blockade in posttraumatic syringomyelia. Thirty-eight Japanese White rabbits, each weighing about 3 kg, were used in this study. The animals were divided into four groups: in Group 1, eight animals received traumatic injury only; in Group 2, 12 animals received traumatic injury following injection of 100 mg kaolin suspended in 1 cc normal saline solution into the subarachnoid space at the site of trauma; in Group 3, nine animals received traumatic injury following injection of 200 mg kaolin in 1 cc normal saline solution into the subarachnoid space at the site of trauma; and in Group 4, nine animals without traumatic injury received an injection of 200 mg kaolin in 1 cc normal saline solution into the subarachnoid space. The subjective criteria for syrinx formation were the presence of a definite round cyst having a smooth margin and an upper or lower extension of more than 2 cm from the injured site. Syrinx formation was seen in 12.5% (one of eight rabbits) in Group 1, 41.7% (five of 12 animals) in Group 2, 55.5% (five of nine rabbits) in Group 3 and 0% (none of nine animals) in Group 4 (p < 0.05). There was a tendency for the combined trauma/kaolin injection groups to be more prone to develop a syrinx. In the kaolin injection only group (Group 4), no animal showed a definite cyst or an extending cavity during the experimental period. The results suggest that kaolin enhances the extension of multiple small cavities that have already formed at the time of initial injury. The difference between the frequency of syrinx formation and the time of survival was statistically significant well beyond the 0.05% level. The overall difference, relating to the frequency of syrinx development, group, and duration of survival, was also statistically significant. In summary, subarachnoid block secondary to adhesive arachnoiditis is important in initiating the extension of the syringomyelia cavity.

Animals↗
PubMed1994

[Two cases of complete transection of the thoracic aorta caused by blunt chest trauma].

Two patients with complete transection of the thoracic aorta, caused by blunt chest trauma, were survived after successful surgical repair. Only seven such cases are reported in the Japanese literature. The present cases were 52- and 28-year-old males injured in different accidents by rapid deceleration, both at collision with the rear of a parked trunk. The first case, on the fifth day of hospitalization, suddenly went into shock with severe thoracodorsal pain. The second case developed hemothorax soon after the accident. Both cases were diagnosed with angiography. The lesions were located in the upper portion of the descending aorta. The operations, performed on the 13th and 34th days after the respective accidents, combined median sternotomy with left thoracotomy through the 3rd intercostal space. The first case suffered complete transection of the aorta at the ductal ligament. In the second case, the intima and media of the descending aorta, at 8 cm below the branching of the left subclavian artery, were affected by complete transection. We operated with a V-A bypass of which cannulation was performed to right atrium and left femoral artery in the first case, and with an ascending aorta-left femoral artery bypass with a centrifugal pump in the second case. The lesions were repaired with 26 mm and 20 mm woven Dacron grafts, respectively. The patients have recovered sufficiently to do normal daily lives. In cases with circumferential transection of the thoracic aorta caused by blunt chest trauma, only those with pseudoaneurysm formation, who remain in a hemostatic state can be saved by surgery, We conclude that if the hemodynamic state is stable and blood pressure is strictly controlled in such cases, the elective operation can be performed.

Adult↗
PubMed1994

[Intra-arterial infusion chemotherapy for recurrent breast cancer via an implantable system--the second report].

Intra-arterial infusion chemotherapy via an implantable port catheter has been applied in 16 patients with locally recurrent breast cancer. The regimen consisted of induction and subsequent maintenance: intra-arterial infusion of epirubicin (EPI). Non-responders were entered into the second-line regimen consisting of Methotrexate and 5-FU (MF). The results were as follows: 1) The response rate (CR+PR) of EPI to locoregional lesions was 50%, and the median duration of response was 5.7 months. 2) The response rate and the duration of response of MF were 25% and 3 months, respectively. 3) Patients with ER-rith, no previous therapy and a long disease-free interval tended to have a high rate of response to intra-arterial infusion therapy. 4) Improvements of QOL, such as intractable pain, infection and severe lymphedema were recognized in 68.6% of the cases. In more than half of the cases, these treatments were carried out in an outpatient clinic. 5) Leucopenia and catheter or portal problems were encountered in 68.6% and 25.0%, respectively. We conclude that intra-arterial infusion chemotherapy via implantable system is a promising modality with regard to therapeutic effect and improvement of quality of life.

Adult↗
PubMed1994

[A case report of emergency surgery for ruptured thoracic aortic aneurysm into the right thoracic cavity].

Rupture of aneurysm of descending thoracic aorta into the right thoracic cavity is an uncommon manifestation and, therefore, carries a high mortality rate. Sixty seven-year-old female was referred to our hospital due to ruptured aneurysm of descending thoracic aorta into the right thoracic cavity. Emergency operation was performed to replace the ruptured descending thoracic aorta through a left thoracotomy and to remove huge hematoma in the right thoracic cavity through a right thoracotomy. Post-operative chest radiograph showed well-expanded right lung which appears to prevent a serious respiratory complication. The patient recovered uneventfully after seven days of respiratory support.

Aged↗
PubMed1994

[CSF dynamics in the patients with syringomyelia associated with Chiari's malformation--quantitative analysis on cine MRI].

In a series of 12 patients with syringomyelia associated with Chiari's malformation, the authors quantitatively analyzed cerebrospinal fluid (CSF) dynamics in the subarachnoid space of the craniospinal junction, using cine MRI combined with pre-saturation method. In most of subjects, cine MRI revealed (1) decreased or increased maximum velocity of CSF in the caudal direction and (2) disturbed CSF motion in the caudal direction (delayed % cardiac cycle) in the craniospinal junction, strongly suggesting disturbed CSF dynamics in the craniospinal junction because of the tonsilar herniation. Of 12 subjects, 8 patients underwent foramen magnum decompression and 4 underwent syringo-subarachnoid shunt (SS shunt). In the patients who showed marked collapse of syrinx after foramen magnum decompression, follow-up cine MRI revealed the normalization of % cardiac cycle, representing postoperative improvement of CSF dynamics in the craniospinal junction. On the other hand, % cardiac cycle did not improve significantly in the patients who did not show marked collapse of the syrinx or suffered from meningitis after surgery. Significant changes were not observed in the patients who underwent SS shunt. In summary, these results suggested that cine MRI combined with pre-saturation method could detect the pathophysiological changes and evaluate the efficacy of the surgery, especially foramen magnum decompression, in the patients with syringomyelia associated with Chiari's malformation.

Adolescent↗
PubMed1994

[Effects of megadose methylprednisolone therapy on acute spinal cord injury in rats].

Present study was performed to confirm the protective effect of megadose methylprednisolone therapy for the posttraumatic spinal cord ischemia. Seventeen Wistar-King rats weighing 215-330 g were divided into four groups which were normal group (n = 5), injury group treated by saline (control group, n = 4), treated by methylprednisolone (MP) 30 mg/kg (n = 4) and treated by MP 60 mg/kg (n = 4). Animals were anesthetized aspirating 1.5% Halothane and made epidural clipping injury (140 g for 3 seconds) at Th7/8 after laminectomy of Th7,8. Saline or MP of which total volume was 1 ml was injected intravenously 30 minutes after injury and spinal cord blood flow (SCBF) was measured 2 hours after injury by using 14C-iodoantipyrine autoradiography technique. As for normal value of spinal cord blood flow, its gray matter is 96.0 +/- 1.5 ml/100 g/min (mean +/- SE), and white matter is 22.9 +/- 1.8 ml/100 g/min. In the gray matter, SCBF severely decreased in all injury groups as it closed to the injury site, and there was no significant difference among these three groups. In the white matter, SCBF decreased at the injury site in all injury groups and there was no significant difference. From rostral to caudal of the injury site SCBF decreased in MP groups, but in the saline group SCBF showed not so much decrease as MP groups at adjacent to the injury site and at more than 3 mm caudal to the injury site increase of SCBF (hyperemia) was observed. And decrease of white matter SCBF was observed in the rostral rather than in the caudal to the injury site in all injury groups. SCBF of the white matter adjacent to the injury site was not decreased, but preserved within normal range or rather slightly hyperemic. These condition may cause the secondary damage in the adjacent spinal cord. It is considered that megadose of methylprednisolone, if it is effective for the spinal cord injury, would suppress the SCBF of white matter of adjacent to the injury site at the acute phase and prevent the progression of secondary damage.

Acute Disease↗
PubMed1994

Symptomatic bilateral extracranial internal carotid artery aneurysms--successfully treated by unilateral aneurysmectomy and saphenous vein graft.

A Japanese case of bilateral extracranial internal carotid artery aneurysms is presented. The main symptom was transient cerebral ischemic attack (TIA) of the right side. An aneurysmectomy and autogenous saphenous venous interposition of the left internal carotid artery were performed. After the operation, the patient has not suffered from TIA.

Aneurysm↗
PubMed1993

Breast cancer in a male patient with prolactinoma.

A 68-year-old man was diagnosed as having left primary breast cancer. Systemic bone roentgenography showed no evident metastasis, however, skull roentgenography revealed ballooning of the sella turcica, suggesting a pituitary tumor, which was subsequently confirmed by computed tomography. Because there was a high serum prolactin level, the pituitary tumor was diagnosed as a prolactinoma. A modified radical mastectomy was performed for the breast cancer, and bromocriptine therapy given for the prolactinoma. Prolactin is known to initiate and promote breast cancer in mice and rats but little is known about its role in human breast cancer. If hyperprolactinemia plays an important role in the tumorigenesis of human breast cancer as it does in mice and rats, the incidence of breast cancer in patients with hyperprolactinemia may be high. To our knowledge, however, only four such cases have been reported. The present rare case of male breast cancer with prolactinoma is discussed with reference to the literature.

Aged↗
PubMed1993

Locoregional immunotherapy of head and neck cancers utilizing allogeneic spleen cells--a report of 2 cases.

Frozen-stored human spleen cells (SC) cultured with streptococcus preparation OK-432 acquired direct cytotoxicity to autologous as well as allogeneic tumor cells. The activated cells started to produce cytocidal cytokine TGIF, which is distinct from previously known cytokines. We examined the possibility of allogeneic adoptive immunotherapy (AIT) using these OK-432-stimulated spleen cells (OK-SC) in two cancer patients. Rapid necrosis of cancer tissue and remarkable decreases of tumor markers in tumor effusion were observed. There were no severe side effects.

Aged↗
PubMed1993

Skeletal muscle glucose transporter gene expression is not affected by injecting growth-hormone-secreting cells in young rats.

To elucidate the diabetogenic effect of growth hormone on glucose metabolism the regulation of glucose transporter (GLUT) gene expression was examined in rat skeletal muscles. Female Wistar-Furth rats were implanted subcutaneously with growth-hormone-producing pituitary tumour (GH3) cells. Animals were killed 4 or 9 weeks after GH3 cell injection. Although body weight, serum growth hormone and insulin-like growth factor I levels were remarkably elevated during the 4-9 week period, serum blood glucose levels were within normal range. Muscles were obtained from the quadriceps muscle, diaphragm and heart, respectively. Northern blot analysis and Western blot analysis were performed using specific cDNA probes and antibodies. During the 4-9 week period, the levels of muscle GLUT1 and 4 mRNA (corrected by beta-actin mRNA level) in each muscle from the rats injected with tumour cells were not significantly different from those of control rats. Chronic elevation of growth hormone in these rats did not cause any change in GLUT 1 and 4 expression compared to the controls during the euglycaemic period. These results provide the first evidence that chronic growth hormone elevation itself does not affect a key gene of in vivo glucose metabolism.

Animals↗
PubMed1993

Three cases of juvenile onset HTLV-I-associated myelopathy with pseudohypoparathyroidism.

Among 201 patients diagnosed with HAM/TSP at Kagoshima University, 21 juvenile onset patients had manifested clinical signs and symptoms at less than 15 years of age. They appeared to have common characteristics such as short stature and slight mental retardation. These signs prompted us to investigate five of them endocrinologically; and three patients with pseudohypoparathyroidism (PHP) were confirmed. Serum calcium levels were low, and human parathyroid hormone (PTH) infusion (Ellsworth-Howard test) caused low response in urinary cyclic AMP and phosphorus excretion. The first case had IgA nephropathy, which is generally associated with infectious diseases, while the second case had muscular lymphocytic infiltration. The mothers of cases 1 and 2, who were both seropositive for HTLV-I, were suspected to have abnormal calcium metabolism based on Ellsworth-Howard test. A brother of case 1 and two sisters of case 3 had also HAM/TSP and short stature. The early clinical onset of HAM/TSP may be due to PTH receptor anomaly and a low level of 1,25-dihydroxyvitamin D, which is deficient in PHP and is involved in the regulation of the immune response. The association with IgA nephropathy or myositis may result from progressive HTLV-I infection.

Adult↗
PubMed1993

Comparison between wedge and needle biopsies for evaluating the degree of cirrhosis.

To examine whether the biopsy method could affect histological evaluation, the volumetric ratio of human liver parenchyma was estimated in specimens from subcapsular and intralobar areas, and also in specimens obtained by needle biopsy (Tru-Cut needle). A new method of morphometric analysis was performed using a computer-aided color image analyzer. Eighteen cirrhotic, 7 fibrotic, and 4 normal liver biopsies were taken during hepatic resection and analyzed. The parenchymal cell volume ratio in the intralobar area was significantly correlated with that in the subcapsular area, and less significantly with needle biopsy samples (r = 0.844, p < 0.001; r = 0.577, p < 0.01, respectively). Both showed one-to-one correspondence. These results suggest that both wedged and needle biopsy samples are appropriate for assessing the degree of fibrosis or cirrhosis, although the sampling variability of the latter is greater than the former.

Adult↗
PubMed1993

Tumoricidal effect of human PBMC following stimulation with OK-432 and its application for locoregional immunotherapy in head and neck cancer patients.

Both cell-mediated and cytokine-mediated antitumor activities were induced in peripheral blood mononuclear cells (PBMC) in short-term culture with streptococcal preparation, OK-432. Kinetic analysis of OK-432-activated killer activity (OKAK) showed that it reached a plateau level much faster (by 48 h of culture) than that detected in PBMC stimulated with recombinant interleukin 2 (rIL-2) (lymphokine-activated killer: LAK). We also found that the tumor growth inhibitory factor (TGIF) activity was produced in the culture supernatant (CSN) of the OK-432-activated PBMC (OK-MC) and the activity synchronously increased with augmentation of OKAK activity. The TGIF activity was rarely found in the CSN of rIL-2-stimulated PBMC. The TGIF activity detected in CSN of OK-MC was further characterized as derived from a cytokine different from interferon gamma (IFN gamma), tumor necrosis factor (TNF), or lymphotoxin (LT) by a neutralization test using monoclonal antibodies to these cytokines. These 48-h-cultured-OK-MC were adoptively transferred (adoptive immunotherapy: AIT) into 19 head and neck cancer patients either alone or in combination with chemotherapy and/or radiation therapy, and their therapeutic effects were examined. AIT was performed by intra-arterial or intratumoral administration of OK-MC. There were no significant side effects observed in this treatment. In these patients, approximately 1-10 x 10(7) cells were transferred into the tumor burden. Of the 19 patients, 17 had primary cancer, and in 6 (6/17;35%) of them complete remission (CR) of the tumor was obtained. Partial remission (PR) was attained in 9 of the 17 patients (9/17; 53%), giving the overall response rate of 88%.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Left ventricular function during exercise after aortic valve replacement.

To evaluate the difference in left ventricular function during exercise after successful aortic valve replacement, left ventricular function was investigated using radionuclide angiography in 12 patients with normal resting left ventricular systolic function. Patients were divided into two groups: Group 1 was comprised of 5 patients after aortic valve replacement for aortic stenosis and group 2 was comprised of 7 patients for aortic insufficiency. Left ventricular ejection fraction increased significantly during exercise in both groups. The increase in systolic arterial pressure to left ventricular end-systolic volume was significantly larger in group 1 than group 2, whereas the increase in left ventricular end-diastolic volume was significantly larger in group 2 than group 1. Thus, increase in left ventricular contractility played an important role in regulating increased left ventricular ejection fraction during exercise in patients with aortic prostheses for aortic stenosis, whereas increase in left ventricular end-diastolic volume played an important role in patients with aortic prostheses for aortic insufficiency.

Adult↗