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Biomedical subjects

Y Mashima

Publications and source records attributed to Y Mashima.

At least 91 records · Page 5Linked to original sources
PubMed1997

[Evaluation of clinical utility of 111In-DTPA-IgG scintigraphy in the detection of inflammation/infection--a report of multicenter phase III clinical trials].

This is the report of phase III study to evaluate the safety and utility of 111In-DTPA-IgG in patients with strongly suspected inflammation/infection. One hundred and forty five patients with suspected sites of inflammation/infection were enrolled in the study. Only a few adverse experiences in one patient were reported, which were interpreted as having a possible relationship to the agent. A total of 171 suspected sites (12 in head and neck, 39 in thorax, 44 in abdomen and pelvis, 62 in musculoskeletal system, and 14 in other regions) were evaluated by investigators at each institute. Out of 171 sites, 18 were determined to be unevaluable, and 12 false negative and 5 false positive cases were observed. Overall sensitivity and specificity was 89.8% and 85.7%, respectively, and the agent proved to be effective in detecting lesions anywhere throughout the body. The analysis of data from this Phase III study indicates that 111In-DTPA-IgG is well-tolerated in patients and effective in determining focal sites of inflammation/infection although the physiological accumulation in some tissues such as the sinus or liver and possible excretion into the gastrointestinal tract may make it difficult to localize lesions.

Aged↗
PubMed1997

Granular-lattice (Avellino) corneal dystrophy in Japanese patients.

PURPOSE: To determine amyloid deposition in the corneas of granular corneal dystrophy in Japanese patients. METHODS: Eight Japanese patients (10 eyes) with a clinical diagnosis of granular corneal dystrophy were investigated clinically and histologically. Each specimen obtained at surgery was stained with hematoxylin-eosin, Masson trichrome or Mallory, and Congo red stain. Amyloid deposit was identified by birefringence and dichroism under cross-polarized light after staining with Congo red. RESULTS: Seven (70%) of the 10 corneal buttons (six of eight patients) had amyloid deposits, as shown by Congo red staining with birefringence and dichroism. Of the six amyloid-positive patients, two patients (who were siblings) showed discrete gray-white corneal deposits with additional linear deposits. This finding is typical of Avellino corneal dystrophy. The corneas of the remaining four patients showed the discrete deposits typical of granular dystrophy. Some of them showed a few whitish fusiform and stellate opacities in the mid stroma, suggestive of Avellino corneal dystrophy. CONCLUSION: The high frequency of amyloid deposits in Japanese patients with granular corneal dystrophy may be caused by an allelic heterogeneity of the gene.

Aged↗
PubMed1996

High-resolution magnetic resonance imaging of the intraorbital optic nerve and subarachnoid space in patients with papilledema and optic atrophy.

OBJECTIVE: To evaluate the orbital portion of the optic nerve and the subarachnoid space using fast spin-echo magnetic resonance imaging in normal subjects and in patients with papilledema or optic atrophy. DESIGN: Measurements of the optic nerve complex on coronal images were made using high-resolution magnetic resonance imaging with fast spin-echo sequences. PATIENTS: Twenty-one patients, including 5 patients with papilledema due to congenital hydrocephalus, intracranial tumors, or meningitis, as well as 16 patients with optic atrophy, were studied. Sixteen healthy volunteers served as controls. MAIN OUTCOME MEASURES: The longitudinal diameter of the optic nerve, the longitudinal outer diameter of the subarachnoid space, the diameter ratio, and the area of the subarachnoid space were determined. RESULTS: In normal subjects, the ring-shaped area of high signal intensity that represented the subarachnoid space was widest behind the globe, then narrowed toward the orbital apex. In patients with papilledema, the area of the subarachnoid space was markedly dilated, the optic nerve was compressed, and the nerve sheath was widened, resulting in a small diameter ratio compared with that of controls. Patients with pallor of the temporal aspect of the optic disc appeared to exhibit dilation of the subarachnoid space; the size of the optic nerve was decreased more than that of the nerve sheath, resulting in a small diameter ratio compared with controls. Patients with complete pallor of the disc, however, exhibited hyperintense optic nerve complexes without a ring-shaped appearance toward the orbital apex. CONCLUSION: Fast spin-echo magnetic resonance imaging appears useful for objectively evaluating the optic nerve and surrounding subarachnoid space in patients with papilledema and optic atrophy.

Adolescent↗
PubMed1996

Comparative study of bone mineral density estimated by various methods of single- and dual-energy quantitative computed tomography: the capability of the four-equation four-unknown method.

A dual-energy (DE) quantitative computed tomography (QCT) method, the four-equation four-unknown method (DEQCT 4E-4U), was assessed and compared to single-energy (SE) QCT and standard DEQCT (two-line method). The results of this study indicate that bone mineral density (BMD) was more accurately estimated by the present method than by the SEQCT or standard DEQCT techniques on the basis of a phantom study when a large fat content was present. The results of both the phantom study and a human study also showed that the present method corrected for fat in estimating BMD in the presence of high-fat content. These findings suggest that use of this method for estimating BMD can provide useful information in studies assessing the metabolic state of bone. We propose that CT numbers estimated from excised vertebral bone marrow can serve as a soft-tissue correction for the present method.

Adult↗
PubMed1996

Scanning electron microscopic observation of basal cells following corneal epithelial abrasion.

By desquamating single layers of corneal epithelial cells by digitonin, we attempted to observe the basal cell layer of corneal epithelium during wound healing by scanning electron microscopy. Central corneal deepithelisation (diameter 7.0 mm) was performed on rabbit eyes. Animals were killed following healing periods of up to 14 days. Half the eyes were treated with digitonin to expose the basal cell layer, and the other half were left untreated to preserve the superficial layer. In non-wounded controls, basal cells were observed as small and columnar-shaped cells. In experimental animals, on day 3 the superficial cells as well as the underlying basal cells were elongated and enlarged. On day 7, the basal cells became columnar in shape, but remained large. Both superficial cells and basal cells returned to normal on day 14. This technique allowed us to observe the morphological reconstruction process of basal cells by scanning electron microscopy.

Animals↗
PubMed1996

High incidence of pre-excitation syndrome in Japanese families with Leber's hereditary optic neuropathy.

Cardiac conduction abnormalities have been reported in families with Leber's hereditary optic neuropathy (LHON). The pre-excitation syndrome Wolff-Parkinson-White syndrome or Lown-Ganong-Levine syndrome, is reportedly common in Finns with LHON, being seen in 14 (9%) of the 163 individuals with mitochondrial DNA (mtDNA) mutations. While this syndrome is thought to be rare in other ethnic groups with LHON, the present study of 35 Japanese LHON families confirmed that it is also relatively common among Japanese families, being seen in 5 (8%) of the 63 individuals with mtDNA mutations. It remains to be determined whether the high incidence of the pre-excitation syndrome in Finnish and Japanese LHON families is due to a particular genetic composition of ethnic groups such as in Finland and in Japan, or only to a reporting bias.

Comorbidity↗
PubMed1996

Heterogeneity and uniqueness of ornithine aminotransferase mutations found in Japanese gyrate atrophy patients.

PURPOSE: To identify mutations in ornithine aminotransferase (OAT) in seven Japanese families with gyrate atrophy (GA), an autosomal recessive chorioretinal degeneration of the eye caused by a generalized biochemical deficiency in OAT; mutations in the OAT gene have shown a high degree of molecular heterogeneity. METHODS: DNA was prepared from patients' fibroblasts and analyzed by polymerase-chain-reaction amplification of the OAT gene sequence, denaturing gradient gel electrophoresis, and direct sequencing for identification of the mutations. RESULTS: Eight different mutations were identified in seven unrelated Japanese GA patients with hyperornithinemia, confirming the high genetic heterogeneity of this disease. Five of these mutations were new, including one causing a pyridoxine-responsive disease, and all eight mutations have been found only in Japanese GA patients. Consistent with some similarity between the Japanese and Finnish populations in genetic isolation and homogeneity, there was a preponderance of homozygous mutations (five out of seven patients) as was previously reported for 16 Finnish GA pedigrees. CONCLUSION: The eight Japanese OAT mutations represent a group of heterogenous mutations unique to a specific population pool.

Amino Acid Sequence↗
PubMed1996

[The presence of IgE on limbal Langerhans cells in patients with atopicdermatitis].

Limbal conjunctival biopsies from 8 patients with atopic dermatitis and from 5 age-matched healthy individuals undergoing cataract or retinal detachment surgery were analyzed by light microscopy and immunological techniques. They were immuno-double labelled with anti-CD1a and anti-IgE or anti-CD23 (IgE receptor). In the specimens from atopic dermatitis 24 approximately 75% of positive anti-CD1a staining cells were double-stained by anti-IgE. Weak positive immuno-double stained cells with anti-CD23 were also observed, but less than with anti-IgE. The ratio of positive anti-IgE double-stained cells to positive anti-CD1a stained cells seemed to be parallel to serum IgE level, but not significant. The presence of IgE and CD23 (IgE receptor) on conjunctival Langerhans cells seems to have a positive effect on IgE-dependent antigen presentation.

Adult↗
PubMed1996

[A histopathological study of corneal amyloidosis secondary to trichiasis].

We present a case of secondary corneal amyloidosis whose etiological mechanism was investigated by immunohistochemistry and electron microscopy. A 48-year-old woman had suffered from trichiasis in the right eye for 35 years, and developed secondary corneal amyloidosis, a phenomenon previously described but whose etiological mechanism has not been explained. Slitlamp examination of the cornea revealed a white excrescence with a diameter of 2 mm. The lesion was excised and examined by light and electron microscopy. Large deposits of an amorphous eosinophilic material were observed beneath the atrophic epithelium. Amyloid was detected in these deposits using Congo red stain, polarized light, and electron microscopy. Neither vascularization nor infiltration of inflammatory cells was observed. Immunohistochemical tests for protein AL, protein AA, prealbumin, beta 2-microglobulin and cytokeratin in paraffin sections were all negative. Characteristic findings were observed in the border zone between the basal cells and the deposits. Numerous digitiform cell processes and membrane-bound globular fragments of basal cells were seen in the superficial region of the deposits. The cell membrane of some globules was interrupted and the contents appeared to have been discharged into the stroma. These findings suggest that basal cells of the corneal epithelium provide an amyloid precursor on the stroma.

Amyloidosis↗
PubMed1996

[Accurate placement of central venous catheters using right atrial electrocardiography].

We have evaluated the effectiveness of central venous catheter placement using right atrial electrocardiography (RAECG). Consecutive patients under general anesthesia (n = 42) who required a central venous catheter underwent RAECG-guided catheter insertion procedure via right internal jugular vein. Catheter tip position was verified by post procedure portable chest radiography. Forty of 42 catheter tips were placed above the superior vena cava-right atrial junction, and none of them had its associated complications. The average insertion depth of catheters was 16.4 cm. We also attempted to predict the optimal catheter insertion depth for each patient from the previous measurements of external landmarks, but it was found to be difficult to predict reliably. In this point of view, we should use RAECG technique to make sure the proper positioning of the catheter tip.

Aged↗
PubMed1996

[Assessment of clinical utility of 111In-DTPA-IgG scintigraphy in the detection of inflammation/infection--a report of multicenter phase II clinical trials].

A Phase II clinical study was performed in patients with strongly suspected focal sites of inflammation/infection to investigate clinical utility of 111In-DTPA-IgG. Neither adverse effects nor abnormal laboratory changes were noted in the all cases. Out of 59 patients, the clinical utility was evaluated in 56 patients with a total of 67 suspicious sites (19 in thorax, 13 in abdomen and pelvis, 30 in musculoskeletal system, and 5 in other regions). True positive results were obtained in 100% of lesions in the thorax (13/13) and the musculoskeletal system (26/26). There were three false negative and five false positive results. Overall sensitivity and specificity was 94.0% and 70.6%, respectively. Most of the true positive scintigram with the best image quality was acquired at Day 1 or Day 2 post-injection. A dose of 80 MBq was considered to be a practical dose for imaging. Our study indicates that 111In-DTPA-IgG is a safe and promising imaging agent for the detection of inflammation/infection, and that it is reasonable to proceed with Phase III studies to further evaluate clinical utility of the agent.

Adult↗
PubMed1995

Risk of false-positive molecular genetic diagnosis of Leber's hereditary optic neuropathy.

PURPOSE/METHODS: The most common pathogenic mitochondrial mutation at nucleotide 11778 in Leber's hereditary optic neuropathy is usually detected by the loss of an SfaNI restriction site. To evaluate a false-positive diagnostic error in this molecular genetic assay, we investigated SfaNI polymorphism in 120 patients with bilateral optic atrophy. RESULTS/CONCLUSIONS: The ratio of false-positive to true-positive results was 1:36. Mitochondrial DNA polymorphism at nucleotide 11779 reflects a false-positive genetic error.

DNA↗
PubMed1995

Sodium hyaluronate eyedrops in the treatment of dry eyes.

BACKGROUND: Several studies in the past have attempted to demonstrate the efficacy of sodium hyaluronate in the treatment of dry eyes. However, results have been conflicting and a definite conclusion has not yet been reached. This study recruited a larger group of patients and has incorporated for the first time both fluorescein and rose bengal staining in the evaluation of the epithelium. METHODS: Eighteen albino rabbit corneas were used in a basic animal study to demonstrate the efficacy of sodium hyaluronate by comparing the effects on the rate of epithelial healing. The optimal concentration to be used in the clinical trial was determined from the results of the basic study. In the clinical study 104 patients with dry eye syndrome were enrolled in a double masked controlled clinical trial. Patients received sodium hyaluronate drops in one eye and control medication in the other eye for 4 weeks. Grading of subjective symptoms and clinical examinations were performed at 2 and 4 weeks. RESULTS: In the animal study sodium hyaluronate at concentrations of 0.1% and 0.5% significantly accelerated the recovery time of iodine vapour induced corneal erosions (p < 0.01). In the clinical study no statistical significance was observed in the improvement of subjective symptoms or rose bengal staining, while fluorescein scores significantly improved in eyes receiving sodium hyaluronate (p = 0.0001) at 4 weeks. CONCLUSION: Sodium hyaluronate drops applied in six daily doses could not be demonstrated to offer advantages over conventional tear supplies in the improvement of subjective symptoms, but may play a role in maintaining a healthy corneal epithelium.

Animals↗
PubMed1995

Corneal epithelium following penetrating keratoplasty.

AIMS: This study was designed to observe any changes to the corneal epithelium after penetrating keratoplasty. METHODS: The corneal epithelia of 26 patients were observed by specular microscopy 1 week, 1 month, 3 months, and 6 months following penetrating keratoplasty. RESULTS: After re-epithelialisation was confirmed by biomicroscopy 1 week after surgery, specular microscopy revealed many abnormal cells, including spindle shaped cells, nucleated cells, large cells, as well as irregular cell configurations. Although these abnormal findings tended to decrease with time, they were still present in some cases as much as 6 months postoperatively. Computerised morphometric analysis yielded mean cell areas of 1121 (SD 168) microns 2, 1139 (675) microns 2, 1712 (496) microns 2, and 1400 (377) microns 2 at 1 week, 1 month, 3 months, and 6 months respectively, all significantly greater than that of age matched controls (710 (151) microns 2). The shape factor decreased with time, but was still greater than the control level at 6 months. CONCLUSIONS: This study demonstrates that epithelial abnormalities persist longer than expected after penetrating keratoplasty, and that these subtle changes can be detected by specular microscopic observation, potentially allowing for modification and enhancement of the wound healing process.

Adolescent↗