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Biomedical subjects

M Usui

Publications and source records attributed to M Usui.

At least 145 records · Page 8Linked to original sources
PubMed1997

Spontaneous occlusion of a giant basilar tip aneurysm and a basilar artery due to the dissection of both structures: case report.

BACKGROUND: Spontaneous occlusion of a giant aneurysm with its parent artery is relatively rare. Complete occlusion of a giant aneurysm at the basilar bifurcation and a basilar artery due to the dissection of the basilar artery has never been reported. CASE DESCRIPTION: This 62-year-old man presented with left hemiparesis and right oculomotor palsy. Radiographic study showed a giant aneurysm at the basilar artery bifurcation with hemorrhage in its wall and an ischemic area in the right midbrain. Subsequent study revealed that thrombosis of the aneurysm rapidly progressed and that the parent basilar artery caused the dissection. Finally the giant aneurysm and the basilar artery were completely thrombosed. CONCLUSION: The dissection was considered to occur in the aneurysm wall first by the hemorrhage in it and progress proximally along the basilar artery. Intramural hemorrhage in the wall of a giant aneurysm can be a cause of dissection of its parent artery. This seems to be one of the mechanisms by which a giant aneurysm and its parent artery are spontaneously thrombosed.

Aortic Dissection↗
PubMed1997

Limb allografts in rats treated with anti-ICAM-1 and anti-LFA-1 monoclonal antibodies.

This study examined whether administration of anti-ICAM-1 mAb (monoclonal antibody) and anti-LFA-1 mAb were effective for inhibition of the acute rejection reaction in a rat-limb allograft model. The grafts were carried out using major histocompatibility complex mismatch pairs of rats: ACI rats as the donors and Lewis rats as the recipients. The subjects were of species with completely different major histocompatibility complexes. The average length of survival in this combination was 4.7 +/- 0.6 days. When anti-ICAM-1, anti-LFA-1 mAb, or a combination of both were administered intraperitoneally at 1 mg/kg body weight daily for 7 days after the graft, the mean survival times were 4.3 +/- 0.6, 4.7 +/- 0.6, or 4.7 +/- 0.6 days, respectively. The agents were found to exercise no beneficial effects for transplants. Transplants were then carried out with a single intramuscular administration of FK506 at 3mg/kg body weight on the day of the operation to observe the effect of this adjunct therapy. The mean survival time averaged 16.0 +/- 5.5 days with FK506 alone. Administration of anti-ICAM-1, anti-LFA-1, and both antibodies together with FK506 resulted in mean survival times of 15.4 +/- 3.0, 25.0 +/- 5.8 and 13.2 +/- 5.8 days, respectively. Thus, a significant prolongation of survival time was observed when the combination of anti-LFA-1 mAb and FK506 was used. In contrast, anti-ICAM-1 mAb and FK506 or both mAb and FK506 showed no beneficial effects.

Animals↗
PubMed1997

Immunogenetic study of sympathetic ophthalmia.

Sympathetic ophthalmia (SO) is very rare but it remains one of the most intractable eye diseases. In clinical manifestations and histopathologic features SO is known to resemble closely Vogt-Koyanagi-Harada's disease (VKH disease). We had reported that VKH disease was significantly associated with HLA-DRB1*04 and -DQB1*04 in Japanese patients. In this study, to investigate an HLA association with SO we performed HLA serological and PCR-based DNA typing in 16 patients and 50 healthy controls. Our study revealed that HLA-DRB1*04 (0405; Pc < 5 x 10(-4)), DQA1*03 (Pc < 5 x 10(-3)), and DQB1*04 (0401; Pc < 5 x 10(-4)) were significantly associated with SO as compared to the healthy controls but there was no significant difference in the frequencies of any DPB1 alleles between the patients and healthy controls. It can be postulated that not only the clinical manifestations but also the genetic predisposition of SO are very similar to those of VKH disease.

Female↗
PubMed1997

Effect of retinol palmitate as a treatment for dry eye: a cytological evaluation.

Vitamin A is known to regulate the proliferation and differentiation of corneal epithelial cells and preserved conjunctival goblet cells and has been used in the treatment of disease of the eye such as dry eye and superior limbic keratoconjunctivitis for some time. This study was undertaken in order to evaluate the efficacy of retinol palmitate aqueous ophthalmic solution under development for the treatment of dry eye failing to respond to the conventional therapy with artificial tears or cornea-protective drugs. Retinol palmitate ophthalmic solution was applied repeatedly for 4 consecutive weeks. Before and after instillation therapy, brush cytology (Cytobrush-S) was performed and cytodiagnosis was made for keratinized cells, nonkeratinized cells, goblet cells and inflammatory cells on samples prepared using an automated smear apparatus (ThinPrep). In dry eye, an increase in goblet cells (1.3+/-2.6-->2.1+/-1.8 cells/slides), a decrease in keratinized cells (11.2+/-16.5-->5.2+/-10.9 cells/300 cells) and, hence, an increase in nonkeratinized cells (287.3+/-16.6-->293.4+/-11.4/300 cells) were found after treatment with retinol palmitate. As to inflammatory cells, there was no change from the pretreatment baseline (1.4+/-1.4-->1.4+/-1.3 cells/300 cells). These results demonstrate that brush cytology suggests the efficacy of retinol palmitate ophthalmic solution in dry eye treatment.

Administration, Topical↗
PubMed1997

Surgical extraction of traumatic orbital mercury.

Initial clinical observation of a 2-year-old boy whose right eyelid had been pierced by a glass thermometer 3 days earlier showed a scab-covered cicatrix and slight swelling in the eyelid. X-ray examination showed the broken thermometer tip, fine glass fragments, and mercury droplets beneath the eyelid and extending along the superior orbital margin. On surgical incision, glass fragments and the thermometer tip were found and extracted from the eyelid and orbital fatty tissue with forceps, and 70.3 mg of mercury droplets were readily removed from the same regions by suction via an elastic needle connected to an injection syringe. Blood mercury gradually rose from the normal range to a peak of 28.4 microg/dl 3 months after surgery, then declined during the following 7 months to a level of 15.1 microg/dl. No abnormality has been found in liver or renal function to present.

Child, Preschool↗
PubMed1997

Chronic angiotensin-converting enzyme inhibition and angiotensin II type 1 receptor blockade: effects on cardiovascular remodeling in rats induced by the long-term blockade of nitric oxide synthesis.

We have shown previously that angiotensin-converting enzyme (ACE) inhibitors prevent coronary vascular remodeling (medial thickening and perivascular fibrosis) and myocardial remodeling (fibrosis and hypertrophy) in rats induced by long-term inhibition of nitric oxide (NO) synthesis with oral administration of N omega-nitro-L-arginine methyl ester (L-NAME). ACE inhibitors inhibit both the formation of angiotensin II and the catabolism of bradykinin. In this study, we aimed to determine the relative contribution of the latter two mechanisms to the beneficial effects of an ACE inhibitor on structural remodeling. First, we examined the effects of the ACE inhibitor temocapril and the angiotensin II AT1 subtype receptor antagonist CS-866 on the structural remodeling induced by administering L-NAME for 8 weeks. Temocapril and CS-866 were equally effective in preventing remodeling. Second, we examined whether the effect of temocapril on the remodeling induced by L-NAME was reduced by the bradykinin receptor antagonist HOE140. The latter drug did not alter the beneficial effect of temocapril on remodeling. In conclusion, although species differences must be considered to apply our conclusion to clinical conditions, the present results suggest that the inhibition of angiotensin II activity, mediated via the AT1 receptors, is responsible for the beneficial effects of an ACE inhibitor in our animal model of coronary vascular and myocardial remodeling induced by the long-term inhibition of NO synthesis.

Angiotensin Receptor Antagonists↗
PubMed1997

Inactivation of the tumor suppressor gene on 11q13 in brothers with familial acrogigantism without multiple endocrine neoplasia type 1.

Two of three brothers (the second and third brothers) and their uncle (their mother's brother) presented acrogigantism without multiple endocrine neoplasia type 1 (MEN 1). An invasive macroadenoma was found in the second brother, and it was histologically confirmed as a sparsely granulated GH cell adenoma. Two distinct microadenomas were found in the third brother, and these were histologically diagnosed as a mixed GH cell and PRL cell adenoma and a sparsely granulated GH cell adenoma, respectively. The loss of heterozygosity (LOH) was analyzed in two adenomas (GH cell adenoma from the second brother and a mixed GH cell and PRL cell adenoma from the third brother) by determining microsatellite polymorphisms of DNAs from tumors and patients' leukocytes. The LOH was found on the chromosome 11q13, whereas LOH was not detected on 1p31-36, 2p, 3p, 4, 5, 6p, 7, 8, 9p21-22, 12p, and 19q13 in both pituitary adenomas examined. The haplotype analysis showed that the same haplotype on 11q13 was found in their mother and the unaffected first brother as well as in the affected uncle and two brothers. The deleted alleles on chromosome 11q13 in the tumors of two affected brothers were, however, restricted to those transmitted from their unaffected father. These data suggest that inactivation of the MEN 1 gene or other tumor suppressor genes on chromosome 11q13 plays an important role for the development of our familial acrogigantism without MEN 1.

Adenoma↗
PubMed1997

The results of transsphenoidal surgery for 44 consecutive acromegalic patients.

A series of 44 patients with acromegaly underwent transsphenoidal surgery between 1987 and 1996. The early postoperative mean basal GH level < 5 ng/ml or < 3 ng/ml was achieved in 43 (97.7%) or 38 (86.4%) out of 44 patients, respectively. Preoperative abnormal GH secretory response to TRH, GnRH and oral glucose administration was restored to normal both after surgery and at the time of the final follow-up in all patients whose early postoperative mean basal GH levels were reduced to < 3 ng/ ml, whereas they remained abnormal in those with mean basal GH levels of > or = 3 ng/ml. In contrast, insulin-like growth factor 1 (IGF-1) levels, when measured by the extraction method, tended to be reduced gradually to normal between 6 months and 2 years after surgery in some patients with a successful operation. Therefore, 34 (87.1%) out of 39 patients who have been followed up longer than 6 months met the following stringent criteria at the time of the final follow-up: mean basal GH level < 3 ng/ml, a normal IGF-1 level, and normal GH response to TRH, GnRH and oral glucose administration. In this series, the most unfavorable preoperative factor influencing operative outcome is tumor invasion of the cavernous sinus. Our results clearly indicate that selective adenomectomy by transsphenoidal surgery is the therapy of first choice in any patient with acromegaly and that the complete biochemical cure of acromegaly can be achieved in 87% of patients by surgery alone with an acceptable low surgical morbidity.

Acromegaly↗
PubMed1997

Occurrence of severe vasospasm following intraventricular hemorrhage from an arteriovenous malformation. Report of two cases.

The authors present two rare cases of severe cerebral vasospasm following the rupture of arteriovenous malformations (AVMs). Computerized tomography revealed intracerebral hemorrhage in the thalamus in one case and in the putamen in the other, both accompanied by cast formation of intraventricular clots without radiological evidence of subarachnoid hemorrhage. Initial angiograms showed arterial narrowing of the bilateral internal carotid arteries in the supraclinoid portion but failed to demonstrate an arteriovenous shunt. Subsequent angiograms clearly demonstrated the existence of an AVM. Radiological features and possible mechanisms are discussed.

Adolescent↗
PubMed1997

The relationship of preoperative magnetic resonance imaging findings and closed system drainage in the recurrence of chronic subdural hematoma.

Although chronic subdural hematoma (CSDH) is a well-known entity, its recurrence rate has remained uncertain. There is little knowledge concerning whether the results of radiological imaging can be used to predict CSDH recurrence or whether surgical methods can influence this rate. The first aim of this study is to evaluate the relationship between the recurrence rate of CSDHs and their appearance on preoperative magnetic resonance (MR) or computerized tomography images. The second aim is to evaluate by means of a prospective randomized method the usefulness of closed-system drainage. From January 1988 through June 1996, the authors surgically treated 257 consecutive adult patients with CSDHs. Data obtained in 199 patients who were evaluated preoperatively by MR imaging were analyzed. Thirty-one of these patients underwent bilateral operations and thus 230 operative sites of CSDH were included in the analyses. The cases of CSDH were separated into high- and nonhigh-intensity groups on the basis of the appearance on T1-weighted MR images. From July 1992 to June 1996, the authors conducted a prospective randomized study on the recurrence rate of CSDH in patients undergoing burr-hole irrigation with or without closed system drainage. The recurrence rate of 3.4% in the high-intensity group was significantly lower than the 11.6% rate found in the nonhigh-intensity group (p < 0.05). The recurrence rates following irrigation with and without closed system drainage were significantly different (p < 0.025): 3.1% with closed system drainage and 17% following burr-hole irrigation alone. The surgical procedures were correlated with the MR findings. In the high-intensity group, 1.1% of CSDHs recurred in patients in whom closed system drainage was used and 11.1% in patients without closed system drainage. In the nonhigh-intensity group, 8.1% of CSDHs recurred in patients in whom drainage was used and 23.1% in patients without closed system drainage. Magnetic resonance T1-weighted imaging was useful in predicting the propensity of CSDHs to recur. Closed system drainage significantly reduced the recurrence rate of CSDHs regardless of MR findings.

Adult↗
PubMed1997

Co-secretion of parathyroid hormone and parathyroid-hormone-related protein via a regulated pathway in human parathyroid adenoma cells.

Parathyroid-hormone-related protein (PTHrP) is widely expressed not only in malignant tumors but also in both epithelial and nonepithelial cells of normal tissues. Secreted PTHrP is suspected to act as a paracrine or autocrine regulator. However, little is known about its secretory pathway. To cast light on this question, we studied the intracytoplasmic distribution of parathyroid hormone (PTH) and PTHrP immunohistochemically and immunoelectron microscopically in 10 surgically resected parathyroid adenomas. Double immunostaining was performed using anti-PTH antibody and a newly established anti-PTHrP antibody to reveal the relationship between their two distributions. Additional examination by cell immunoblot assay was performed to determine whether both PTH and PTHrP are secreted simultaneously. Both PTH and PTHrP were actually secreted from individual parathyroid cells simultaneously on cell immunoblot assay. Immunohistochemically, there were two different types of adenoma cells, i.e., one positive only for PTH and the other positive for both PTH and PTHrP. PTH was distributed linearly or fine granularly along the cytoplasmic membrane, whereas PTHrP was distributed diffusely or coarse granularly in the cytoplasm. The intracytoplasmic distributions of PTH and PTHrP often overlapped. Immunoelectron microscopical examination demonstrated that PTHrP co-localized with PTH in the same secretory granules. The results clearly demonstrated that PTHrP can be co-secreted with PTH via a regulated pathway using secretory granules.

Adenoma↗
PubMed1997

[A study of 44 patients with Kirisawa type uveitis].

We studied 50 eyes of 44 patients with acute retinal necrosis, Kirisawa type uveitis (KU), in order to examine clinical symptoms, pathogenic viruses, clinical grading, therapy and prognosis for this disease. Varicella-zoster virus (VZV) was the pathogenic organism in 37 eyes of 31 patients, while herpes simplex virus (HSV) was responsible in 13 eyes of 13 patients. There were more elderly patients in the VZV-KU group than in the HSV-KU group. In addition, mutton fat keratic precipitates and retinal exudates were more common in VZV-KU than in HSV-KU. We divided KU eyes into 3 clinical grades: severe, serious, and mild. Using statistical analysis, we found that the VZV-KU group had a significantly greater number of severe and serious cases than the HSV-KU group. Furthermore, some HLA antigens were found to be statistically more common in the VZV-KU group, although no associations were found in the HSV-KU group. 32% of VZV-KU and 67% of HSV-KU eyes had a final visual acuity (fVA) of greater than 0.5. When eyes with an fVA of greater than 0.1 were compared to eyes with an fVA of less than 0.1, we found that combined therapy using acyclovir, interferon beta, and prednisolone was especially effective for VZV-KU, although no significant difference was found for HSV-KU. Thus, it is essential to determine the pathogenic virus causing KU, in order to understand the disease pathogenesis as well as to select appropriate treatment.

Adult↗
PubMed1997

Distal posterior interosseous nerve syndrome.

Five patients presenting with chronic dorsal wrist pain and diagnosed as distal posterior interosseous nerve syndrome are reported. Clinical examination revealed point tenderness of the fourth extensor compartment. The symptoms were reproduced by extreme wrist extension in all patients and by extreme flexion in three of the patients. The pain was relieved in all patients by a selective lidocaine block of the terminal branch of the posterior interosseous nerve at the wrist joint. All the patients failed to respond to nonoperative treatment and underwent surgical exploration of the nerve. The operative findings were an enlarged nerve in three patients and adhesion of the nerve to the joint capsule in five patients. A 2 cm section of the nerve proximal to the extensor retinaculum was resected. Four of the five patients had excellent pain relief and returned to full asymptomatic activity. One patient had improvement in pain and was satisfied with the outcome. A diagnosis of distal posterior interosseous nerve syndrome should be considered if the usual sources of dorsal wrist pain are eliminated.

Adolescent↗
PubMed1997

[Cervico-omo-brachial pain and disability in a person of advanced age].

A person of advanced age usually has degenerative changes of bone, joint and ligament, which can be causes of cervico-omo-brachial pain and disability. He or she may also suffer from metastatic bone tumor of cervical spine or upper extremity. This article described pathology, signs and symptoms and recent treatment of these diseases. Cervical myelopathy and radiculopathy, which are most common causes of cervico-omo-brachial symptoms, are sometimes accompanied by peripheral entrapment neuropathy such as cubital tunnel syndrome or carpal tunnel syndrome (double crush syndrome). In this complicated situation, decompression of neural tissue in both cervical spine and carpal tunnel are necessary. In treatment for carpal tunnel syndrome, release of transverse carpal ligament under an arthroscope has proven to be useful and has been becoming popular. This minimally invasive surgery is also useful in shoulder surgery such as subacromial decompression in aged patients with rotator cuff tear and removal of calcium deposit in the shoulder joint. Osteoarthritis of the elbow also cause pain or disability of the elbow and the hand. Some metastatic bone tumors are treated by tumor resection and reconstruction with instruments, prosthesis or composite grafts, which are attempted not to cure the disease but to maintain or improve the quality of life of the patient.

Aged↗
PubMed1997

[Three cases of thymic hyperplasia associated with hyperthyroidism].

We encountered three cases of thymic hyperplasia associated with hyperthyroidism. Case 1 was in a 35-year-old woman; a chest CT scan showed an anterior mediastinal mass and right-sided pleural effusion, which suggested the presence of a thymoma Case 2 was in a 21-year-old man who complained of palpebral ptosis and also had myasthenia gravis (Osserman type I). Case 3 was in a 47-year-old woman; a chest CT scan showed thymic hyperplasia and mediastinal lymphadenopathy. In all cases, anti-thyroid medication was given first, because of the associations with hyperthyroidism. Moreover, in cases 1 and 2 no tumor was found, and only hyperplasia was detected in the thymus, although both patients underwent extended thymectomy. Furthermore, surgery was not effective against the hyperthyroidism (anti-thyroid medication could not be withdrawn or reduced). In cases 2 and 3, thymic hyperplasia, as seen on chest CT scans, resolved as thyroid function was normalized by anti-thyroid medication. The pretracheal lymphadenopathy seen in case 3 also resolved. Thymic hyperplasia may have been a result, not a cause, of hyperthyroidism. When we encounter patients with thymic masses and hyperthyroidism, we should give anti-thyroid medication and observe the thymus for some time before resorting to surgery.

Adult↗
PubMed1997

[Inhibition of experimental autoimmune uveoretinitis by transforming growth factor-beta 1 in B10. A mice].

Experimental autoimmune uveoretinitis (EAU) in mice, an organ specific autoimmune disease, has been investigated as an animal model for human endogenous uveitis. In this study, we report on the immunosuppressive effect of transforming growth factor-beta 1 (TGF-beta 1) on the development of EAU in mice. Inhibition by TGF-beta 1 of proliferation of interphotoreceptor retinoid-binding protein (IRBP)-specific T cell lines in B10.A mice against IRBP antigen was dose-dependent. However, when spleen cells used as the antigen presenting cell were first cultured with TGF-beta 1, this anti-proliferation effect was abolished. When IRBP-immunized mice were injected intraperitoneally with TGF-beta 1, dose-dependent suppression of EAU was obtained. The proliferation response of lymph node cells from TGF-beta 1 injected mice with IRBP-induced EAU was suppressed compared with phosphate buffered saline (PBS)-injected mice. These findings suggest that TGF-beta 1 may be a cytokine that plays a role in suppressing IRBP induced EAU in mice.

Animals↗