Biomedical subjects

A Sawada

Publications and source records attributed to A Sawada.

At least 19 recordsLinked to original sources

PubMed1997

Role of screening for hepatitis C virus in children with malignant disease and who undergo bone marrow transplantation.

BACKGROUND: Children with malignant disease who received multiple blood transfusions before the clinical definition of hepatitis C virus (HCV) require evaluation for HCV infection. STUDY DESIGN AND METHODS: The role of HCV infection in 54 children with primary malignant disease was evaluated in terms of the following aspects: prevalence of HCV infection, distribution of HCV subtype, the benefit of screening of blood donors, and the presence of chronic liver disease. The benefit of screening for HCV in a subset of patients who underwent bone marrow transplantation (BMT) was also evaluated. RESULTS: Seventeen patients (31.4%) of 54 tested were seropositive in a second-generation HCV antibody test. Thirteen patients (24.0%) were also positive for circulating HCV RNA. HCV subtype 1b and HCV subtype 2b were found in six and two patients, respectively. Multiple HCV genotypes were present in two patients. One of these two patients had relatively progressive liver disease. Before the introduction of blood screening with a second-generation HCV antibody test, 15 of 35 patients seroconverted, whereas none of 7 patients seroconverted after the screening was used (p = 0.032). For patients who underwent BMT, the screening drastically decreased the seroconversion rate, from 7 of 11 patients to 0 of 6 (p = 0.016). CONCLUSION: A considerable number of children with primary malignant disease who received multiple blood transfusions became infected by HCV before HCV screening was used. Patients who underwent BMT were at high risk for HCV infection. Screening with a second-generation HCV antibody test has proven to be remarkably beneficial in preventing HCV infection in these children.

Adolescent↗

PubMed1997

The nurse shortage problem in Japan.

This article discusses the serious problem of the shortage of about 50,000 nurses in Japan today. If efficient measures to solve it are not adopted by administrators, it is clear that the shortage will become still more alarming in the future, in a society with more people in advanced years and in which the numbers in the younger generation will decrease from now on. The main factors behind the Japanese nursing labour shortage are, among others: a rapid increase in the number of hospital beds between 1986 and 1989, poor working conditions; and nurses' low social position in their places of work. Behind these factors, there has always been a contempt for the art of nursing in our society. Why has Japanese society made light of nursing? Three points can be identified: traditional discrimination against women; our disregard for a religious mentality; and our short history of hospital nursing. To overcome these problems, we must first of all change fundamentally our sense of values, such as love for one another and compassion. We must now reconstruct a caring culture in our society.

Cultural Characteristics↗

PubMed1997

Progressive retinitis-encephalitis due to ganciclovir-resistant cytomegalovirus associated with aplastic anemia.

A 29-year-old woman with aplastic anemia who complained of visual disturbances and pain in the right eyeball was diagnosed as having cytomegalovirus (CMV) retinitis based upon the characteristic retinal changes and isolation of CMV. She received treatment with ganciclovir (GCV), and the retinitis initially responded for several months. However, the patient was found to have CMV lesions in the left eye followed by neurological symptoms. The CMV isolated just before her death was approximately 20 times more resistant to GCV than that isolated previously, suggesting that the GCV-resistant CMV had developed during the long-term treatment with GCV.

Adult↗

PubMed1997

Appositional angle closure in eyes with narrow angles: an ultrasound biomicroscopic study.

PURPOSE: To demonstrate appositional angle closure using ultrasound biomicroscopy under dark room conditions, to investigate patterns of appositional closure, and to correlate those patterns with the angle topology in eyes with narrow angles. METHODS: Forty-six eyes that met the study criteria, from 46 individuals, were examined by ultrasound biomicroscopy under dark room and illuminated conditions. RESULTS: In 40 of the 46 eyes (87.0%), appositional closure was identified by ultrasound biomicroscopy. Two distinct patterns of angle closure were seen: type B, in which closure starts from the bottom of the angle, and type S, in which closure starts in the vicinity of Schwalbe's line. In type B, the iris root was located closure to the chamber angle than in type S. CONCLUSIONS: Ultrasound biomicroscopy performed under dark room conditions is a useful technique for identifying appositional angle closure in eyes with narrow angles. The topology of the iris root is related to the pattern of the appositional angle closure.

Adult↗

PubMed1997

Use of antifibrosis agents and glaucoma drainage devices in the American and Japanese Glaucoma Societies.

PURPOSE: To investigate practice patterns among glaucoma subspecialists in the American Glaucoma Society (AGS) and the Japanese Glaucoma Society (JGS), regarding use of antifibrosis agents and glaucoma drainage devices. METHODS: An anonymous survey incorporating 10 clinical situations was mailed to all AGS and JGS members in December 1995. RESULTS: Half of the AGS (105 of 210), and JGS (25 of 50) members returned surveys. Most respondents (51-87%) preferred trabeculectomy with adjunctive mitomycin for all 10 clinical situations. Mitomycin concentrations varied from 0.1 to 0.8 mg/ml (range of means for 10 situations 0.31-0.39 mg/ml) and intraoperative application times ranged from 5 s to 7 min (range of means for 10 situations 2.5-4.6 min). Preferences for either no antifibrosis agent (up to 39%) or 5-fluorouracil (up to 29%) were highest in primary trabeculectomy. Thirty-seven percent to 64% of AGS members used glaucoma drainage devices, especially after complicated postsurgical glaucomas (after penetrating keratoplasty, scleral buckling, or pars plana vitrectomy) and in neovascular glaucoma, but few JGS members used them. Large differences between university- and private practice-based AGS members were found only in mitomycin use for primary trabeculectomy (33% vs. 52%, respectively; p = 0.07) and for complicated postsurgical glaucomas (46% vs. 70%, respectively; p = 0.03). CONCLUSIONS: Trabeculectomy with mitomycin was the preferred surgical procedure among AGS and JGS members in the clinical situations surveyed. Mitomycin concentration and time of application varied widely. Many respondents used 5-fluorouracil or no antimetabolite in primary trabeculectomy. Glaucoma drainage devices were widely used for complicated glaucomas in the United States.

Chemotherapy, Adjuvant↗

PubMed1996

Ultrasound biomicroscopic findings of acute angle-closure glaucoma in Vogt-Koyanagi-Harada syndrome.

PURPOSE: We studied a case of Vogt-Koyanagi-Harada syndrome with transient shallow anterior chamber and increased intraocular pressure as initial manifestations. METHODS: We examined the patient using ultrasound biomicroscopy and speculated on the mechanisms of increased intraocular pressure. RESULTS: Ultrasound biomicroscopic examinations revealed the swollen ciliary body with anterior rotation and supraciliary space at the time of increased intraocular pressure. CONCLUSIONS: We confirmed that the swollen ciliary body with anterior rotation and supraciliary space caused transient angle-closure glaucoma in this patient with Vogt-Koyanagi-Harada syndrome.

Acute Disease↗

PubMed1996

Prevention of visual field defect progression with brovincamine in eyes with normal-tension glaucoma.

PURPOSE: A prospective investigation of the effect of brovincamine fumarate, a Ca2+-channel blocker, on visual field changes in normal-tension glaucoma (NTG). METHODS: A total of 28, age- and field-matched, patients with NTG were allocated randomly to either brovincamine fumarate (20 mg 3 times daily) or placebo (3 times daily). The patients were followed at least every 4 months for a minimum of 2.5 years, and visual field examinations were carried out at least every 6 months. The mean follow-up periods (+/-standard deviation) were 39.1 +/- 8.7 months in the brovincamine-treated group and 37.9 +/- 10.1 months in the placebo group. Stepwise discriminant analyses were performed to separate the patients who showed improvement of their visual fields from those who failed to improve in the brovincamine-treated group, and to identify factors that may determine the visual field prognosis of all patients with NTG enrolled in the study. RESULTS: In the brovincamine-treated group, six patients showed visual field improvement, whereas none showed improvement in the placebo group using the Statpac 2 linear regression analysis. Discriminant analyses identified better cold recovery rate and higher initial systolic blood pressure to be significantly contributory to a favorable outcome in the brovincamine-treated group, and the use of brovincamine, better cold recovery rate, and higher initial systolic blood pressure were identified to be significantly contributory to a favorable prognosis in all subjects. CONCLUSION: Brovincamine seems to have a favorable effect on visual field in at least some patients with NTG.

Administration, Oral↗

PubMed1996

Primary low cerebrospinal fluid pressure syndrome with galactorrhea: findings at MR imaging.

A case of primary low cerebrospinal fluid (CSF) pressure syndrome with galactorrhea is reported. Magnetic resonance imaging demonstrated diffusely enhanced meninges, edematous brain, and enlarged pituitary gland. Coincidental enlargement of pituitary gland and edematous brain due to low CSF pressure compressed the pituitary portal system. The low-perfused anterior lobe of pituitary gland would be the mechanism of galactorrhea.

Adult↗

PubMed1996

Autosomal dominant cone-rod dystrophy associated with a Val200Glu mutation of the peripherin/RDS gene.

OBJECTIVE: Mutations of the peripherin/RDS gene have been reported in several kinds of retinal dystrophy, and they show a variety of manifestations. The authors identified a novel Val200Glu mutation of the peripherin/RDS gene in a Japanese family with autosomal dominant cone-rod dystrophy (CRD). This report describes a genotype-phenotype correlation of the Val200Glu mutation. PATIENTS AND METHODS: Fifteen members of one Japanese family with autosomal dominant CRD were screened for mutations in the peripherin/RDS and ROM 1 genes. Clinical features were identified by visual acuity, visual field testing, fundus examination, and electroretinography. RESULTS: A Val200Glu mutation was found in all of the affected family members examined and was segregated with the disease. No patient had a mutation in the ROM 1 gene. Phenotypic characteristics of each affected member in this family showed intrafamilial similarity. Characteristic features included cone function more severely impaired than rod function and degenerative change in the macular region associated with peripheral retinal degeneration. CONCLUSION: The mutation at codon 200 of the peripherin/RDS gene causes both cone and rod degeneration. The Val200Glu mutation results in a type of autosomal dominant CRD.

Adult↗

PubMed1996

Surgery for refractory glaucoma.

PURPOSE: To determine the surgical outcome of mitomycin trabeculectomy in patients with refractory glaucoma. METHODS: Sixty-six eyes of 52 patients with refractory glaucoma underwent mitomycin trabeculectomy. Mitomycin was applied for five minutes only once during trabeculectomy. The follow-up period was six to 61 months. RESULTS: Cumulative success probability was calculated using Kaplan-Meier life-table analysis assuming the cut-off postoperative IOP to be 20 mmHg or IOP reduction by at least 20% in eyes with preoperative IOP 24 mmHg. At the end of 61-month follow-up the success probability was 80% +/- 6% without postoperative ocular hypotensive medication (complete success) and was 95% +/- 3% regardless of postoperative antiglaucoma medication (overall success), respectively. CONCLUSION: The data suggest that mitomycin trabeculectomy is efficacious in reducing IOP in patients with refractory glaucoma.

Adolescent↗

PubMed1996

Retinitis pigmentosa with recurrent vitreous hemorrhage.

We observed recurrent vitreous hemorrhage in two patients with retinitis pigmentosa: a 41-year-old female and a 49-year-old male. At age 41, the first patient had diffuse capillary dilatation, macular microaneurysms, and paramacular macroaneurysms in the right eye. At age 47, similar retinal vascular lesions and disc neovascularization developed in the left eye followed by recurrent vitreous hemorrhage. The retinal microvascular changes and vitreous hemorrhages subsided spontaneously during the ensuring 4 years. In the second case, recurrent vitreous hemorrhage developed in the right eye. Funduscopy and fluorescein angiography at age 49 revealed no angiopathy. However, 2 years later we detected retinal neovascularization in the macula and an avascularity in the peripheral retina in the right eye. Subretinal exudate or retinal detachment was consistently absent in both cases.

Adult↗

PubMed1996

Electrical responses from locally detached retina and its recovery after reattachment.

Alterations in the focal electroretinogram (FERG) after experimental retinal detachment and spontaneous reattachment in albino rabbits were studied. Retinal detachments of two disc diameters were produced by injecting balanced salt solution into the subretinal space. FERGs were obtained under direct fundus visualization by an infrared television fundus camera with a light stimulator. The preoperative b-wave amplitude and implicit time were 0.52 +/- 0.07 microV and 59.7 +/- 3.8 ms (mean +/- SD), respectively. Thirty minutes after retinal detachment, the amplitude decreased significantly to 0.05 +/- 0.09 microV (p < 0.0001). The next day, we confirmed retinal reattachment ophthalmoscopically and the amplitude recovered to 0.30 +/- 0.07 microV. Then it gradually increased to 0.54 +/- 0.07 microV 7 days after the operation. The implicit time increased significantly to 66.6 +/- 4.1 ms 30 min after retinal detachment (p < 0.01), was maximal the day after surgery (69.9 +/- 4.9 ms), and thereafter shortened. However, the implicit time did not recover completely and was significantly delayed compared with preoperatively even 28 days postoperatively (65.4 +/- 3.4 ms, p < 0.01). These data suggest that functional abnormalities persist in the reattached rabbit retina, even following a brief retinal detachment.

Animals↗

PubMed1996

Nitric oxide-sensitive and -insensitive contractions of the isolated rabbit iris sphincter muscle.

PURPOSE: The rabbit iris sphincter muscle is innervated by cholinergic and tachykinergic nerves that regulate its tone. To clarify the involvement of nitric oxide (NO) in the postsynaptic regulation of the rabbit iris sphincter muscle tone, the authors examined the effects of NO-related agents on the cholinergic contraction induced by carbamylcholine (carbachol) and the tachykinergic contraction induced by neurokinin A. METHODS: The motor activity of the ring-shaped rabbit iris sphincter muscle was measured isometrically. Sodium nitroprusside (SNP, a NO donor) was administered between the first and second administrations of carbachol and neurokinin A, each of which induced sustained contraction. The effects of carboxy-2-phenyl-4,4,5,5,-tetramethyl-imidazoline-l-oxyl-3-oxide (carboxy-PTIO, a scavenger of NO radicals), NG-monomethyl-L-arginine (L-NAME, an inhibitor of NO formation from L-arginine), and methylene blue (an inhibitor of soluble guanylate cyclase) on contractions induced by carbachol and neurokinin A also were studied. Cyclic guanosine monophosphate (GMP) content in the muscle was determined by radioimmunoassay. RESULTS: Sodium nitroprusside inhibited carbachol-induced contractions of the iris sphincter muscle in a concentration-dependent manner but had no effect on neurokinin A-induced muscle contractions. Carboxy-PTIO and methylene blue significantly diminished the inhibitory effect of SNP on carbachol-induced contractions. L-NAME had no effect on contractions induced by either carbachol or neurokinin A. Sodium nitroprusside alone increased cyclic GMP accumulation in a concentration-dependent manner. CONCLUSIONS: This study showed that SNP inhibited cholinergic contractions mainly through a cyclic GMP-dependent mechanism but did not affect the tachykinergic contractions, indicating that cholinergic contraction is NO sensitive, whereas tachykinergic contraction is NO insensitive. These findings suggest that in rabbits, the cholinergic and tachykinergic responses have distinct features for the fine adjustment of the iris sphincter muscle tone.

Animals↗

PubMed1996

[Multi-focal electroretinograms in normal subjects].

The multi-focal electroretinogram (multi-focal ERG), developed by Sutter (1992), is a method of recording the spatial distribution of focal ERG in a short time using multi-input stimulation. Using this technique, we can detect the spatial extent and severity of damage to the macula. In this study, we recorded multi-focal ERGs from 20 eyes of 20 normal subjects and analyzed the topographical property of responses. In every subject, a negative wave followed by a positive wave could be recorded and we named them the N1-wave and the P1-wave, respectively. The amplitudes of the N1-wave and the P1-wave were the largest in the fovea and they became smaller with eccentricity. In P1-wave amplitude, the greatest inter-subject variability was observed at the fovea. The N1 and P1 latencies were shorter in the upper retina than in the lower retina. The amplitude was larger in the upper retina than in the lower retina, which suggests functional superiority of the upper retina. There was no statistical difference of latency and amplitude between nasal and temporal retina. We found no statistical difference between the responses of the papillomacular bundle and those of the temporal retinal area. The mapping obtained by multi-focal ERG was useful as objective perimetry.

Adult↗

PubMed1996

[A case of morning glory syndrome associated with contractile movement of the optic disc and subretinal neovascularization].

We report a rare case of morning glory syndrome with choroidal neovascular membrane and contractile movement of the optic disc. A 12-year-old healthy boy was first seen in April 1992 with a chief complaint of transient visual loss in his left eye for 3 months. The diagnosis of morning glory syndrome was made by the characteristic optic nerve head. His visual acuity was 1.2 in both eyes. In August 1994, retinal hemorrhage associated with choroidal neovascular membrane was observed in the macula of his left eye, resulting in a decrease of visual acuity to 0.4. In October 1994, we observed contractile movement in the morning glory optic disc. Using a scanning laser ophthalmoscope (SLO), we could observe the disc contracting for approximately 2 seconds and then dilating again over a 20-second period. The contractile movement was not evoked by exposure to a strong light or by the Valsalva maneuver. However, it seemed to be induced by digital massage of the eyeball.

Child↗

PubMed1996

Effect of vitrectomy on epiretinal membranes after endogenous fungal endophthalmitis.

Pars plana vitrectomy was used to remove proliferative membranes caused by endogenous fungal endophthalmitis in 3 patients (3 eyes). Tractional retinal detachment was present in all. In 2 eyes, a fibrovascular membrane originated in the optic nerve head and was connected to a full-thickness chorioretinal scar. In the other, a thick preretinal membrane was found in the macula, with total retinal detachment. In all eyes, the epiretinal membrane was successfully removed and the retina reattached. Visual outcome depended on the site of the chorioretinal scar. We advocate pars plana vitrectomy as the method of choice for tractional retinal detachment following fungal endophthalmitis.

Endophthalmitis↗

PubMed1995

A comparative study of intraocular irrigating solutions: effects on electroretinography readings during closed vitrectomy in humans.

The effects of intraocular irrigating solutions on electroretinography have been extensively studied in animal models, but effects on human electroretinography have not been reported. This study examined the effects of two commercially available irrigating solutions, S-MA2 (Opeguard MA) and DE-057 (BBS-Plus) on 30-Hz flicker electroretinography during closed vitrectomy in humans. Eight eyes of 8 patients were examined. All patients underwent a simple vitrectomy without treatment of proliferative membrane. For 30-Hz flicker electroretinography recording, a contact lens with a built-in light-emitting diode was sterilized and used as both a stimulus source and a recording electrode. Replacing S-MA2 with DE-057 decreased the electroretinography amplitude from 55.8 +/- 15.2 to 45.5 +/- 13.2 microV (mean +/- SEM). Changing the irrigation solution from DE-057 back to S-MA2 increased the amplitude from 45.5 +/- 13.2 to 59.9 +/- 17.3 microV. However, these changes were not statistically significant. Replacing S-MA2 with DE-057 significantly increased the peak time from 50.1 +/- 1.5 to 57.6 +/- 1.3 msec (p < 0.001). This change was reversible; after changing from DE-057 back to S-MA2, the peak time of flicker electroretinography significantly decreased from 57.6 +/- 1.3 to 49.0 +/- 2.1 msec (p < 0.01). Thus intraoperative 30-Hz electroretinography showed delayed peak time during irrigation with DE-057, as compared with S-MA2. The lower potassium concentration and higher glucose concentration of S-MA2, as compared with DE-057, may be the cause of such electroretinography changes.

Aged↗

PubMed1995

Effects of adenosine on chick retinal pigment epithelium: membrane potentials and light-evoked responses.

We examined the effects of adenosine, a putative mediator of neuroprotection during cerebral ischemia, on the electrophysiological characteristics of retina-retinal pigment epithelium-choroid preparations obtained from 1-7 day-old chick and maintained in vitro. Our experiments produced the following results. First, superfusion of the retinal surface with adenosine (0.1 mM) increased the trans-tissue potential. The trans-epithelial (but not the trans-retinal) potential was also increased to the same magnitude with a time-course similar to that of the trans-tissue potential. Second, adenosine produced a depolarization of the epithelial basal plasma membrane with a concomitant decrease in its basal membrane resistance. Third, the trans-epithelial (but not the trans-retinal) c-wave in response to a light stimulus was augmented by adenosine. Adenosine reduced the hyperpolarization of the epithelial basal membrane, but had no effect on the extracellular concentration of K+ in the subretinal region. Fourth, the light-peak that was elicited with a 300 s light stimulus was also depressed by adenosine. Fifth, when 4,4'-diisothiocy anostilbene-2,2'-disulfonate (DIDS), a relatively selective inhibitor of Cl- channels, was perfused at 50 microM on the choroidal surface, adenosine-induced increases in the trans-tissue potential and the c-wave were both abolished. These results suggest that adenosine increased the Cl- conductance of the basal plasma membrane of the retinal pigment epithelium and thereby augmented the standing potential as well as the light-elicited membrane potentials of the retinal pigment epithelium, which seems to be involved in the pathophysiology of retinal ischemia.

4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid↗