Search PubMed⌕ Search

Biomedical subjects

J Akiba

Publications and source records attributed to J Akiba.

At least 37 records · Page 2Linked to original sources
PubMed1998

Multiple inflammatory pseudotumors of the liver associated with acute myeloblastic leukemia.

A 26-year-old man, diagnosed with acute myelogenous leukemia had multiple inflammatory pseudotumors (IPT) in the liver. The patient presented complete remission after remission induction therapy, and then showed right upper quadrant discomfort and intermittent fever. An ultrasonography disclosed multiple hypoechoic nodules in the liver. A biopsy of the nodules showed focal liver cell necrosis with scant inflammatory cells, compatible with IPT. After several courses of chemotherapy, the nodules in the liver increased. The second liver biopsy of the nodule showed fibrosis. Multiple IPTs in the liver should be distinguished from abscess and metastatic nodules.

Adult↗
PubMed1998

[Scrotum exfoliative dermatitis with ulcers associated with treatment of acute promyelocytic leukemia with all-trans retinoic acid].

All-trans retinoic acid (ATRA) induces complete remission (CR) in most cases of acute promyelocytic leukemia (APL). Toxicity of ATRA has been shown to be mild and consist of headache, dry skin, dermatitis, gastrointestinal disorders, and hypertriglyceridemia. We report three patients with APL treated with ATRA in combination with chemotherapy, who developed scrotum exfoliative dermatitis with ulceration. Their age was 33 years (range, 25 to 37). All three cases developed scrotum erosions, and many small ulcers after 9 to 17 days of ATRA treatment. The scrotum exfoliative dermatitis with ulceration occurred repeatedly, but gradually resolved in about 8 weeks time. They developed no dryness of the lip or skin apart from the scrotum. All three cases continued to receive 45 mg/m2 of ATRA daily throughout induction therapy, and achieved CR. We suspected the scrotum exfoliative dermatitis with ulceration to be a side effect of ATRA. The scrotum lesions, which have been already reported may be common in patients receiving ATRA.

Adult↗
PubMed1997

Transient corneal edema induced by nitric oxide synthase inhibition.

The aim of the study is to identify nitric oxide synthase (NOS) in the rabbit cornea and further investigate the physiological role of nitric oxide in the rabbit cornea. For histological identification, an immunohistochemical technique using anti-NOS monoclonal antibodies was employed. For the physiological study, we measured the corneal thickness in vivo as an indicator of corneal edema by ultrasonic pachymetry. The measurements were repeated before and after ipsilateral injections of N(G)-nitro-L-arginine methyl ester (L-NAME) or N(G)-nitro-D-arginine methyl ester (D-NAME) or 6-anilino-5,8-quinolinedione (LY-83583) with contralateral injection of vehicle (balanced salt solution) into the anterior chamber of the rabbit. We also monitored intraocular pressure (IOP) by pneumatonometry. Endothelial NOS (eNOS) immunoreactivity was demonstrated both in the corneal epithelium and the endothelium. The corneal thickness significantly increased after L-NAME or LY-83583 without significant rise of IOP, whereas no change was detected after vehicle or D-NAME. These results suggest that NO is spontaneously produced in the corneal endothelium and the NO/cyclic GMP pathway is involved in maintainance of corneal thickness.

Aminoquinolines↗
PubMed1997

Association between the short-term natural history of diabetic macular edema and the vitreomacular relationship in type II diabetes mellitus.

PURPOSE: The authors ascertain the association between the short-term natural history of untreated diabetic macular edema and the vitreomacular relationship. METHODS: The authors prospectively studied 82 type II diabetic patients with clinically significant macular edema over a six-month period. They used multiple linear regression analysis to evaluate the effect of ten variables on the short-term natural history of macular edema 6 months after diagnosis: age; gender; diabetes duration at diagnosis of macular edema; hemoglobin A1; insulin use; presence of proteinuria; presence of systemic hypertension, cardiac disorders, or both; degree of diabetic retinopathy; history of panretinal photocoagulation; and vitreomacular relationships, as determined by present lens biomicroscopy. RESULTS: At study entry, 22 (27%) eyes had vitreomacular separation and 60 (73%) eyes did not. Macular edema spontaneously resolved in 27 (33%) eyes 6 months after diagnosis. Of the 22 eyes with vitreomacular separation at study entry, 12 (55%) had spontaneous resolution of macular edema after 6 months, whereas only 15 of 60 (25%) of the eyes with vitreomacular adhesion at study entry had spontaneous resolution (P = 0.01). Stepwise regression analysis indicated that vitreomacular separation (P = 0.01) and diabetes duration (P = 0.03) contribute to resolution of macular edema. Of the 27 eyes with resolved macular edema, 17 (63%) had improved visual acuity of more than two lines, whereas no eyes had improved visual acuity if macular edema persisted. The prevalence of improved visual acuity of more than two lines was significantly higher in eyes with vitreomacular separation at study entry (36%, 8/22) than in eyes without (15%, 9/60; P = 0.04). CONCLUSION: Our findings suggest that vitreomacular separation may promote the spontaneous resolution of diabetic macular edema and consequently improve visual acuity.

Adolescent↗
PubMed1997

Novel point mutation in the leucine-rich motif of the platelet glycoprotein IX associated with Bernard-Soulier syndrome.

Bernard-Soulier syndrome (BSS) is a rare inherited bleeding disorder which is caused by a qualitative or quantitative abnormality of the platelet glycoprotein (GP) Ib/IX/V complex. We examined a patient with BSS to find a molecular basis for the defect underlying this disease. The propositus was a 39-year-old Japanese female with life-long bleeding diathesis. Sequence analysis of the GPIX gene revealed a T-->C point mutation at nucleotide 1856 (EMBL, M80478), resulting in Phe55(TTT)-->Ser(TCT) replacement. This substitution created a new MnlI restriction site in the mutant allele. Restriction analysis revealed that the propositus was homozygous for this sequence, and the same mutation was not detected in 57 unrelated Japanese subjects. Since this mutation is located in the leucine-rich motif (LRM) of the GPIX polypeptide, the Phe55-->Ser substitution may result in an alteration of the LRM which leads to the impaired surface expression of GPIb/IX/V complex, a characteristic of BSS.

Adult↗
PubMed1997

Variations of posterior vitreous detachment.

AIMS: To identify variations in posterior vitreous detachment (PVD) and establish a clinical classification system for PVD. METHODS: 400 consecutive eyes were examined using biomicroscopy and vitreous photography and classified the PVD variations-complete PVD with collapse, complete PVD without collapse, partial PVD with thickened posterior vitreous cortex (TPVC), or partial PVD without TPVC. RESULTS: In each PVD type, the most frequently seen ocular pathologies were as follows: in complete PVD with collapse (186 eyes), age related changes without vitreoretinal diseases (77 eyes, 41.4%) and high myopia (55 eyes, 29.6%); in complete PVD without collapse (39 eyes), uveitis (23 eyes, 59.0%) and central retinal vein occlusions (8 eyes, 20.5%); in partial PVD with TPVC (64 eyes), proliferative diabetic retinopathy (30 eyes, 46.9%); and inpartial PVD without TPVC (111 eyes), age related changes without vitreoretinal diseases (62 eyes, 55.9%). This PVD categorisation was significantly associated with the prevalence of each vitreoretinal disease (p < 0.0001, chi 2 test on contingency table). CONCLUSIONS: PVD variations can be classified into four types, which is clinically useful because each type corresponds well to specific vitreoretinal changes.

Adult↗
PubMed1997

Copper-ion-catalyzed vitreous liquefaction in vivo.

To investigate copper-ion (Cu2+)-catalyzed vitreous liquefaction in vivo, Cu2+ solution (10 mumol) was injected into the vitreous cavity of rabbits. At 24 h after the injection, the gel and liquid vitreous were weighed, and the percent of vitreous liquefaction was calculated. Cu2+ injection resulted in liquefaction of 58% of the vitreous, although control eyes had 12% liquefaction (p < 0.1). The vitreous liquefaction was more pronounced in the presence of exogenous ascorbic acid. However, the addition of mannitol, a hydroxyl-radical-specific scavenger, significantly suppressed the Cu(2+)-catalyzed vitreous liquefaction. The free radicals generated by the Cu(2+)-catalyzed oxidation system may cause vitreous liquefaction in vivo.

Animals↗
PubMed1997

Role of the vitreous and macular edema in branch retinal vein occlusion.

BACKGROUND AND OBJECTIVE: To determine the relationship between macular edema associated with branch retinal vein occlusion (BRVO) and the condition of the vitreous. PATIENTS AND METHODS: The authors retrospectively studied 58 patients (58 eyes) who underwent vitreous examination. The eyes were classified as having vitreomacular attachment (VMA) or vitreomacular separation (VMS), and were divided into two groups based on the mean age of the patients. RESULTS: Macular edema was found in 39 (67%) of the eyes. The prevalence of VMA was 81% (22 of 27 eyes) in group 1 (patients who were 64 years old or younger) and 45% (14 of 31 eyes) in group 2 (patients who were older than 64 years). Although no significant relationship was found, 77% (17 of 22) of the eyes with VMA in group 1 had macular edema. The incidence of macular edema was significantly higher in eyes with VMA (93%, 13 of 14) than in eyes with VMS (41%, 7 of 17, P = .009) in group 2. CONCLUSION: The authors' findings suggest that VMA may influence the presence of macular edema associated with BRVO.

Adult↗
PubMed1996

Imaging of epiretinal membranes in macular holes by scanning laser ophthalmoscopy.

PURPOSE: Because recognition and removal of an epiretinal membrane are important in macular hole surgery, we used the scanning laser ophthalmoscope preoperatively to study epiretinal membranes in patients with idiopathic macular holes. METHODS: We studied 67 eyes (60 consecutive patients) with idiopathic macular holes. We evaluated the thickness and the extent of the epiretinal membrane by using a scanning laser ophthalmoscope. We then compared the fundus images obtained with the scanning laser ophthalmoscope with red-free monochromatic fundus photographs. RESULTS: Confocal imaging of the fundus with either argon blue (488 nm) or argon green (514 nm) laser illumination clearly showed the epiretinal membranes. In all eyes, we observed lesions ranging from a patchy glinting light reflex to a dense epiretinal membrane. A well-demarcated dense epiretinal membrane around the macular hole was observed in seven (44%) of 16 eyes with stage 2 macular holes and in 12 (40%) of 30 eyes with stage 3 holes, but in only two (10%) of 21 eyes with stage 4 holes. The prevalence of the dense epiretinal membrane in stage 2 or 3 holes was significantly higher than in stage 4 holes (P = .025 and .024, respectively). CONCLUSIONS: Fundus imaging using the scanning laser ophthalmoscope with argon laser illumination is useful preoperatively to evaluate epiretinal membranes in eyes with idiopathic macular holes.

Aged↗
PubMed1996

Differential diagnosis of macular breaks by microperimetry using the scanning laser ophthalmoscope.

To improve the differential diagnosis of macular breaks by microperimetry using the scanning laser ophthalmoscope (SLO), we studied 50 consecutive breaks detected by biomicroscopy and indirect ophthalmoscopy. The full-thickness macular break was easily diagnosed using only biomicroscopy and indirect ophthalmoscopy because the macular break had a cuff in 22 of the eyes. SLO microperimetry also showed an absolute scotoma within the macular break and a relative scotoma on the cuff in these 22 eyes. However, in the other 28 eyes it was impossible to distinguish between the full-thickness macular breaks and pseudo-macular breaks or lamellar macular breaks using only biomicroscopy and indirect ophthalmoscopy because of the absence of a cuff. However, SLO microperimetry differentiated full-thickness macular breaks from pseudomacular breaks or lamellar macular breaks in these 28 eyes. SLO microperimetry is indispensable for determining the prognosis of and the surgical indication requirements for idiopathic macular breaks.

Diagnosis, Differential↗
PubMed1996

Clinical characteristics of traumatic macular holes.

The clinical characteristics of 20 eyes of 20 consecutive patients with traumatic macular hole were studied retrospectively. The macular holes were elliptical with irregular edges in 19 eyes (95%) and ranged in size from 0.2 to 0.5 DD (disc diameter). Posterior vitreous detachment (PVD) was found in only 3 eyes (15%); the vitreous was detached from the macula in only one of these 3. Other conditions found in the 20 patients included commotio retinae, vitreous hemorrhage, hyphema, and choroidal rupture. These findings strongly suggest that most traumatic macular holes develop in the absence of PVD and that the pathogenesis is independent of the occurrence of PVD. We believe that the macular rupture (hole) is caused mechanically by the force of the impact on the posterior pole and the ocular deformity which result from blunt trauma.

Accidents↗
PubMed1995

Serum-induced collagen gel contraction.

PURPOSE: To understand the molecular events underlying disease-related vitreous gel contraction, the effect of serum components on collagen was investigated. METHODS: Bovine vitreous or dermal collagen was incubated with a mixture of transglutaminase (TG; factor XIIIa) and fibronectin (FN), and the biochemical changes of collagen were monitored by gel electrophoresis. In addition, serum-induced changes in the volume of the collagen gel were monitored. RESULTS: Gel electrophoresis revealed a new high-molecular-weight band (M(r) 240,000) presumably due to intermolecular cross-links of collagen peptides and FN. The serum components also were shown to cause a significant decrease in the volume of the collagen gel. CONCLUSION. Collagen gel contraction could be attributed to the collagen-FN-collagen cross-links catalyzed by TG.

Animals↗
PubMed1995

Prognosis of stage 2 macular holes.

PURPOSE: We ascertained the natural course of stage 2 idiopathic macular holes to determine better treatment possibilities. METHODS: We reviewed 48 eyes with stage 2 idiopathic macular holes and followed them up for more than two years. At each examination, best-corrected Snellen visual acuity was measured by a physician masked to the hypothesis of the study. RESULTS: Stage 2 lesions progressed to stage 3 or 4 during the follow-up period in 32 (67%) and 14 (29%) of 48 eyes, respectively; two eyes (4%) remained in stage 2. In 41 (85%) of 48 eyes, the hole size enlarged during the follow-up: 32 (94%) of 34 eyes had vitreomacular attachment and nine (64%) of 14 eyes had vitreomacular separation at the final examination, for a statistically significant difference in prevalence (P = .03). Visual acuity decreased two or more Snellen lines during the follow-up period in 34 (71%) of 48 eyes, the prevalence of which was significantly higher in eyes with vitreomacular attachment at the final examination (28 of 34, 82%) than in eyes with vitreomacular separation at the final examination (six of 14, 43%) (P = .01). CONCLUSION: Even though vitreomacular separation may improve the prognosis of a macular hole, stage 2 lesions usually will develop an enlarged hole and decreased visual acuity.

Aged↗
PubMed1995

Spontaneous resolution of foveal detachments and macular breaks.

PURPOSE: To evaluate the mechanism of spontaneous resolution of foveal detachments and idiopathic macular breaks. METHODS: We reviewed the records of 139 consecutive eyes (94 patients) with either a foveal detachment or a macular break in patients who were examined between 1989 and 1992. There were 26 men and 68 women (mean age, 66.9 +/- 6.9 years). They were either unoperated on or observed during the period that preceded surgery. Each patient underwent complete ophthalmic examination in addition to slit-lamp photography of the vitreomacular interface and microperimetry with the scanning laser ophthalmoscope. RESULTS: Eight eyes demonstrated spontaneous resolution. A foveal detachment was noted in five eyes (five patients) and a stage 2 macular break in three eyes (three patients). The mean duration of observation was 33 months (range, one to 144 months). Resolution of the foveal detachments occurred without the development of posterior vitreous detachment. In each eye, the presence of a pseudo-operculum, indicating vitreofoveal separation, was accompanied by flattening of the foveal detachment without detectable posterior vitreous detachment. The three eyes with stage 2 macular break resolved after premature development of a posterior vitreous detachment. CONCLUSIONS: Foveal detachment and macular break resolution seem to result from the release or weakening of vitreous traction on the fovea. Reattachment of the foveal retina preserves fair to good visual acuity. Surgical intervention is contraindicated (1) in eyes in which foveal detachment flattens and develops a pseudo-operculum and (2) when a posterior vitreous detachment develops in an eye with a stage 2 macular break. Careful biomicroscopic vitreous examination and microperimetry with the scanning laser ophthalmoscope are extremely useful methods for adequate examination of these patients.

Aged↗