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Biomedical subjects

Masayuki Matsumoto

Publications and source records attributed to Masayuki Matsumoto.

At least 19 recordsLinked to original sources
PubMed2006

Heterozygous and homozygous mutations in PITX3 in a large Lebanese family with posterior polar cataracts and neurodevelopmental abnormalities.

PURPOSE: The PITX3 gene, which codes for a homeobox bicoidlike transcription factor is responsible for dominant cataract and anterior segment mesenchymal dysgenesis in humans. In the current study, a family with autosomal dominant posterior polar cataract (PPC) and a PITX3 mutation that cosegregates with the disease was examined. Also studied were two siblings who were homozygous for the PITX3 mutation who had microphthalmia and significant neurologic impairment. METHODS: A genome-wide screen, linkage analysis in the PITX3 chromosomal region 10q25, haplotype analysis, and sequencing of the PITX3 gene were performed on 28 affected and 14 unaffected member of a three-generation Lebanese family. RESULTS: Genome-wide linkage analysis showed a lod score of 3.56 at theta = 0.00 on chromosome 10 at area q25. Analysis of the haplotypes and phenotypes confined the disease locus to a region on 10q25 between the markers D10S1239 and D10S1268. A candidate gene, PITX3, maps to that region. Sequencing of the PITX3 gene revealed a heterozygous G deletion mutation in 25 of the 42 family members. In addition, two siblings from a consanguineous marriage were found to be homozygous for the deletion. CONCLUSIONS: This is the first report of homozygous PITX3 mutations in humans. The phenotype in these individuals highlights the role of PITX3 in ocular and central nervous system (CNS) development.

Cataract↗
PubMed2006

[A ninety-eight-year-old woman with ruptured pancreatic anaplastic mucinous cystadenocarcinoma].

A 98-year-old woman was admitted to our hospital complaining of anorexia, epigastralgia, and vomiting. An elastic hard tumor was palpable in her epigastric region. CT and US examination revealed a huge cystic lesion adjacent to the left lobe of the liver and the stomach. Her serum levels of CEA (13.6 ng/ml), CA19-9 (95 U/ml) and CA125 (99 U/ml) were high. She suffered from aspiration pneumonia on the 10th day of admission, which progressed to acute respiratory distress syndrome. On the 20th day of admission, the epigastric tumor suddenly disappeared. She passed away on the 31st day due to respiratory failure. Autopsy revealed that she had a ruptured pancreatic anaplastic mucinous cystadenocarcinoma. To the best of our knowledge, this is the oldest reported case of ruptured pancreatic cystadenocarcinoma in the world.

Aged, 80 and over↗
PubMed2005

Air-driven eye shutter system for vision experiments using awake behaving animals.

When conducting physiological and behavioral experiments for vision research, we often need to present stimuli monocularly. In this report, we describe a new eye shutter system that was developed to occlude individual eyes during experiments with awake behaving animals. The eye of choice is occluded by an air pressure-driven opaque mask, the opening and closing of which is controlled by computer. This new eye shutter system has several advantages over other systems: (1) it can completely shield the eye from light using a physically opaque eye mask; (2) contamination of electrophysiological recordings by electrical noise is avoided because the actuator is not electrical; (3) the left and right eyes can be randomly occluded in each trial; (4) space for apparatus in front of the animal's face is not required. We used this eye shutter system to record neural activity from the primary visual cortex of awake monkeys and confirmed that this system is suitable for the monocular presentation of visual stimuli during electrophysiological recordings from awake animals.

Air↗
PubMed2005

Neural responses in the macaque v1 to bar stimuli with various lengths presented on the blind spot.

Although there is no retinal input within the blind spot, it is filled with the same visual attributes as its surround. Earlier studies showed that neural responses are evoked at the retinotopic representation of the blind spot in the primary visual cortex (V1) when perceptual filling-in of a surface or completion of a bar occurs. To determine whether these neural responses correlate with perception, we recorded from V1 neurons whose receptive fields overlapped the blind spot. Bar stimuli of various lengths were presented at the blind spots of monkeys while they performed a fixation task. One end of the bar was fixed at a position outside the blind spot, and the position of the other end was varied. Perceived bar length was measured using a similar set of bar stimuli in human subjects. As long as one end of the bar was inside the blind spot, the perceived bar length remained constant, and when the bar exceeded the blind spot, perceptual completion occurred, and the perceived bar length increased substantially. Some V1 neurons of the monkey exhibited a significant increase in their activity when the bar exceeded the blind spot, even though the amount of the retinal stimulation increased only slightly. These response increases coincided with perceptual completion observed in human subjects and were much larger than would be expected from simple spatial summation and could not be explained by contextual modulation. We conclude that the completed bar appearing on the part of the receptive field embedded within the blind spot gave rise to the observed increase in neuronal activity.

Action Potentials↗
PubMed2005

Reduction of pneumonia risk by an angiotensin I-converting enzyme inhibitor in elderly Japanese inpatients according to insertion/deletion polymorphism of the angiotensin I-converting enzyme gene.

BACKGROUND: We have reported that use of angiotensin I-converting enzyme (ACE) inhibitor, which is a class of antihypertensive agent that induces cough, is an independent factor in reducing risk of pneumonia among elderly inpatients. Insertion/deletion (I/D) polymorphism of the ACE gene (ACE) has been associated with the risk of pneumonia in elderly individuals. However, the ability of ACE inhibitors to reduce pneumonia-related morbidity in individuals with the ACE polymorphism is unclear. Therefore we determined the association of ACE inhibitor use and ACE genotypes with reduction of pneumonia risk in the Japanese elderly population. METHODS: We conducted a hospital-based, retrospective, case-control study to evaluate the effect of an ACE inhibitor and ACE polymorphism on incidence of pneumonia. Case subjects were pneumonia patients (N = 105) >or=65 years of age, during an 8-month period of a nonwinter season. Control subjects (n = 420) were elderly patients who were frequency matched to the case subjects by age (within +/- 2 years) and gender. Data were collected on medication with the ACE inhibitor temocapril and on known risk factors for pneumonia. The significances of differences for the risk factors were analyzed using univariate and multivariate comparisons of the case and control subjects. RESULTS: After adjustment for potential confounders by multiple logistic regression analysis, the odds ratio (OR) estimates for pneumonia were 0.458 (95% confidential interval [CI]: 0.230 to 0.909, P = .026) for ACE inhibitor use. Conditional logistic regression analysis according to ACE genotypes revealed significant reduction of pneumonia risk by use of temocapril compared with that in nonhypertensive individuals (ie, the reference group) in those with ACE ID + II (OR: 0. 416, 95% CI: 0.177 to 0.976, P = .044), but not in those with ACE DD (OR: 0.706, 95% CI: 0.198 to 2.518, P = .592). CONCLUSION: These results suggest that use of an ACE inhibitor is beneficial for reducing risk of pneumonia, particularly in individuals with the ACE genotypes ID + II.

Aged↗
PubMed2005

[Guidelines for antihypertensive treatment of elderly hypertensive patients without complications based on EBM].

Hypertension is one of the most significant risk factors for cerebrovascular and heart diseases, which rank as the second and third most frequent causes of death in Japan, respectively. The prevalence of hypertension rises as the population grows older, affecting approximately 60% of the Japanese aged 65 yr or older, and there are currently more patients receiving treatment for hypertension than for any other disease in Japan. As the size of the elderly populations in our country continuously increases rapidly, hypertension has become one of the most important diseases to be treated. Based on the results of numerous clinical intervention trials, treatment of hypertension in the elderly, including treatment of systolic hypertension, has generally been of great benefit. However, the efficacy of treatment of so-called very old hypertensive patients aged 85 yr or older is still controversial. Recently, Guidelines for the Management of Hypertension of Japanese Society of Hypertension (JSH 2004) has been reported, which are based on evidence-based medicine(EBM), adopting the results of mega-trials in Japan and in Western countries, but also considering the lifestyle of Japanese. This paper explaines the part of "Antihypertensive Treatment of Elderly Hypertensive Patients without Complications" in the Guidelines.

Aged↗
PubMed2005

[Treatment of hypertension in elderly patients with coronary heart disease].

Many clinical trials have been conducted to prevent cardiovascular complications and reduce mortality in hypertensive patients. Undoubted, but limited effects of beta-blocker and diuretic antihypertensive drugs had been established. Although angiotensin-converting enzyme inhibitor and angiotensin II receptor antagonist lowered the incidence of events and mortality less than classical antihypertensive drugs, recent studies revealed that prompt and enough lowering the blood pressure is more important than choosing the types of drugs.

Adrenergic beta-Antagonists↗
PubMed2004

Matrix extracellular phosphoglycoprotein (MEPE) is highly expressed in osteocytes in human bone.

The matrix extracellular phosphoglycoprotein (MEPE) gene is highly expressed in tumors that cause oncogenic hypophosphatemic osteomalacia (OHO). MEPE is also known as one of the bone-tooth matrix proteins and is associated with bone mineralization. We developed a rabbit polyclonal antibody directed against recombinant human MEPE (rhMEPE) after cloning its cDNA from the cDNA library of a nasal tumor tissue causing OHO. Using this antibody, we analyzed the distribution of MEPE in human bones by immunohistochemistry. In bone specimens from normal subjects, MEPE was predominantly expressed by osteocytes and not by osteoblasts. In bone specimens from patients with osteomalacia, however, MEPE was focally expressed by deeply located osteocytes. We also compared the MEPE positivity of osteocytes in mineralized bone and non-mineralized osteoid obtained from patients with osteomalacia and osteoporosis. Among osteomalacia patients, MEPE positivity was seen in 87.5 +/- 8.6% of the osteocytes from mineralized bone compared with 7.8 +/- 6.4% of those from osteoid. Among osteoporosis patients, MEPE positivity was found in 95.3 +/- 0.5% of the osteocytes from mineralized bone compared with 4.9 +/- 5.7% of those from osteoid. MEPE was mainly expressed by osteocytes embedded in the matrix of mineralized bone from patients with osteomalacia or osteoporosis. Our data provide the first histological evidence that MEPE is predominantly expressed by osteocytes in human bone, with significant expression by osteocytes within mineralized bone.

Animals↗
PubMed2004

Relationship between NMF (lactate and potassium) content and the physical properties of the stratum corneum in healthy subjects.

Natural moisturizing factor (NMF) of the stratum corneum (SC) has been established to play important roles in the physical properties of the SC. Few studies, however, have investigated the specific influences of NMF components other than the amino acids. In this study, therefore, we focus on the relationship between the ion content and physical properties of the SC in 40 healthy subjects. Changes in the physical properties of the SC induced by the extraction of NMF were equivalent to the changes that took place from summer to winter, demonstrating the important role of NMF in the physical properties of the SC in healthy subjects. The seasonal changes in the physical properties of the SC from summer to winter were accompanied by significant decreases in the levels of lactate, potassium, sodium, and chloride in the SC. Lactate and potassium were the only components found to correlate significantly with the state of hydration, stiffness, and pH in the SC. Interestingly, the levels of lactate and potassium in the SC were also significantly correlated. Moreover, potassium lactate restored the SC hydration state decreased by extraction of NMF. These results suggest that lactate and potassium may play roles in maintaining the physical properties of the SC in healthy subjects.

Adult↗
PubMed2003

Effects of baicalin, baicalein, and wogonin on interleukin-6 and interleukin-8 expression, and nuclear factor-kappab binding activities induced by interleukin-1beta in human retinal pigment epithelial cell line.

The objective of the study was to investigate the effects of baicalin, baicalein, and wogonin (plant flavonoids) on interleukin-6 (IL-6) and interleukin-8 (IL-8) protein production, mRNA expression, and nuclear factor-kappaB (NF-kappaB) binding activities induced by interleukin-1beta (IL-1beta) in human retinal pigment epithelial cell line (ARPE-19) cells. To induce IL-6 and IL-8 mRNA expression and protein levels, IL-1beta was added to serum-free medium of ARPE-19 cells and incubated. The flavonoids were added to the medium. IL-6 and IL-8 in the media were measured using enzyme-linked immunosorbent assay. Both IL-6 and IL-8 mRNA were measured by semiquantitative reverse transcription polymerase chain reaction. The binding activities of the transcription factor NF-kappaB complexes to IL-6 and IL-8 were measured by electrophoretic mobility shift assay. IL-6 and IL-8 in the culture media of ARPE-19 cells were increased by IL-1beta in a dose-dependent manner. Baicalin did not suppress IL-1beta-induced IL-6 and IL-8 production, but dexamethasone, baicalein, and wogonin, significantly suppressed IL-6 and IL-8 production. Elevation of IL-6 and IL-8 mRNA was not suppressed by baicalin but was significantly suppressed by dexamethasone, baicalein, and wogonin. NF-kappaB binding activities were not suppressed by baicalin and baicalein, but was suppressed by wogonin. Wogonin and baicalein inhibited IL-1beta-induced IL-6 and IL-8 mRNA and protein production in ARPE-19 cells. The data suggest that wogonin may inhibit IL-6 and IL-8 mRNA expression via the suppression of NF-kappaB binding activities.

Anti-Inflammatory Agents↗
PubMed2003

Bacterial endophthalmitis after small-incision cataract surgery. effect of incision placement and intraocular lens type.

PURPOSE: To determine whether endophthalmitis after small-incision cataract surgery is affected by the incision site (superior sclerocorneal versus temporal cornea) or the foldable intraocular lens (IOL) material (silicone versus acrylic). SETTING: Multicenter study. METHODS: Patients who had small-incision cataract surgery at Toyama Medical and Pharmaceutical University Hospital and affiliated hospitals from March 1998 to March 2001 were examined prospectively. The patients were randomized into 3 groups. In Group A, an acrylic IOL (MA60BM, Alcon) was implanted through a temporal corneal incision. In Group B, an acrylic IOL (MA60BM) was implanted via a superior sclerocorneal incision. In Group C, a silicone poly(methyl methacrylate) IOL (SI-40NB, Allergan) was implanted via a superior sclerocorneal incision. Each patient was followed for more than 6 months. RESULTS: Initially, 7622 patients (12 317 eyes) agreed to participate in the study. The final study included 3831 eyes in Group A, 3901 eyes in Group B, and 3863 eyes in Group C. Postoperative endophthalmitis was diagnosed clinically in 11 eyes (0.29%) in Group A, 2 (0.05%) in Group B, and 2 (0.05%) in Group C. Endophthalmitis proven by culture was found in 9 eyes in Group A, 2 in Group B, and 2 in Group C. The incidence of endophthalmitis in Group A was higher than in the other groups. The incidence of endophthalmitis in Group B was similar to that in Group C. The relative risk of postoperative endophthalmitis proven by culture in Groups B and C was 4.6 times (P =.037) lower than in Group A. CONCLUSION: The findings suggest that a temporal corneal incision may lead to an increased risk of postoperative endophthalmitis and that the IOL material does not affect the incidence of this complication.

Acrylates↗