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Biomedical subjects

I Watanabe

Publications and source records attributed to I Watanabe.

At least 109 records · Page 6Linked to original sources
PubMed1999

[Influence of wearing complete dentures on body balance in edentulous elderly].

The influence of wearing complete dentures on body balance of edentulous elderly was examined in this study. Eight edentulous volunteers (5 females and 3 males) who were satisfied with their new dentures participated in the study. Static and dynamic balance were compared between subjects with and without dentures. To evaluate static balance, path length of spontaneous postural sway with eyes closed was measured for 60 seconds using a stabilometer. To evaluate dynamic balance, gait cycle, gait velocity, and stride length during 15 meters of free gait were measured using a newly-developed gait-cycle-analyzing device and gait-speedometer. The data analysis showed that path lengths of subjects when wearing complete dentures significantly decreased compared to subjects without dentures (p < 0.05). Subjects when wearing complete dentures performed significantly faster and more stable gait compared to subjects without dentures (p < 0.05). Significant increases were concurrently observed in frequency of gait cycle and stride length (p < 0.05). The results suggested that the presence of an established occlusal vertical dimension had an influence not only on static balance but also on dynamic balance of the subjects. It was concluded that for edentulous elderly, wearing complete dentures may enhance body balance rather than not wearing a complete denture.

Aged↗
PubMed1999

[Chromatic aberration in pseudophakic eyes].

PURPOSE: To evaluate the chromatic aberration of the eyes with a poly (methylmethacrylate) (PMMA) intraocular lens or a soft acrylic intraocular lens (AcrySof), by comparing them with normal eyes. SUBJECTS AND METHODS: The longitudinal chromatic aberration (LCA) of the eye was measured by a modified chromoretinoscopy of Bobier & Sivak, for 48 eyes with a PMMA intraocular lens, 49 eyes with an AcrySof, and 27 eyes with a normal lens. In addition, these LCAs were calculated theoretically by the paraxial ray-tracing technique with a personal computer. RESULTS: The average values of the LCA between the wavelengths of 500 nm and 640 nm were 0.75 +/- 0.18 D (mean +/- standard deviation) in PMMA eyes, 1.20 +/- 0.22 D in AcrySof eyes, and 0.82 +/- 0.16 D in normal eyes. The calculated LCA was 0.64 D in the PMMA eye, 0.98 D in the AcrySof eye, and 0.74 D in the normal eye (Gullstrand's thematic eye). CONCLUSION: The PMMA eyes had chromatic aberrations almost equal to those of the normal eyes, whereas the AcrySof eyes have significantly larger aberrations. Therefore, we conclude that quality of the retinal image is reduced in eyes with an AcrySof lens.

Acrylates↗
PubMed1999

Scanning electron microscopy of the rat tongue mucosa with special attention to the bacteria on epithelial cell membranes.

The authors examined the filiform and fungiform papillae surfaces of rat tongue by scanning electron microscopy showing the numerous groupings of bacteria on the epithelial cell membranes. The fungiform papillae were round in shape and present few bacteria. The epithelial cell of filiform papillae revealed numerous streptococci. The grouping of the bacteria are attached on the epithelial cell membrane, demonstrating three-dimensional SEM images.

Animals↗
PubMed1999

Masticatory ability in relation to oral status and general health on aging.

In recent years in the field of clinical dentistry, and particularly in gerodontics, there has been a growing awareness of the importance of nutrition. Because a lack of masticatory ability leads to an impaired nutritional status, the dentist must be abreast of current knowledge on masticatory ability. Although there are many approaches to the measurement of masticatory ability with natural or functional teeth, there is no ideal method for this measurement in the elderly. This is because the elderly are usually missing more than half of their teeth, and thus have various dentitions. For example, the dentition of 70-years old subjects varies from no missing teeth to no remaining teeth. Moreover, the prosthetic appliances used vary from partial dentures to complete dentures. The present study was performed to establish a method for the objective assessment of masticatory ability which could be applied to the elderly, with their various dentitions. We demonstrated a useful jelly of varying hardness (G-1 jelly) for this assessment. In addition, we examined the correlation between masticatory ability, oral status and general health of the elderly, using this new assessment method.

Aged↗
PubMed1998

Molecular approaches for production of pravastatin, a HMG-CoA reductase inhibitor: transcriptional regulation of the cytochrome p450sca gene from Streptomyces carbophilus by ML-236B sodium salt and phenobarbital.

We have characterized the transcriptional regulation of ML-236B.Na and phenobarbital-inducible cytochrome P450sca-2 (CytP450sca-2) from Streptomyces carbophilus, an industrial pravastatin-producing strain. ML-236B.Na and phenobarbital enhanced the expression of the cytP450sca-2 gene in S. carbophilus. The cytP450sca-2 gene was also ML-236B.Na-inductive in S. lividans. Analysis of various deletion and mutation of the 5'-flanking region of the cytP450sca-2 gene revealed that the 1-kb region was required for ML-236B.Na-dependent CytP450sca-2 induction. We have found a putative ORF in the 5'-flanking region that encodes a protein of 174 amino acid residues containing a helix-turn-helix DNA-binding motif. A gel mobility shift assay showed that the protein was bound by an imperfect palindromic sequence between -46bp and -24bp in the 5'-flanking region, and ML-236B.Na was found to inhibit its binding. These findings suggest that induction of cytP450sca-2 is negatively regulated at the transcriptional level and that the protein encoded by the putative ORF is possibly functional as a repressor of the cytP450sca-2 gene.

Amino Acid Sequence↗
PubMed1998

Studies on inhibitors of mammalian DNA polymerase alpha and beta: sulfolipids from a pteridophyte, Athyrium niponicum.

Three sulfolipid compounds, 1, 2, and 3, have been isolated from a higher plant, a pteridophyte, Athyrium niponicum, as potent inhibitors of the activities of calf DNA polymerase alpha and rat DNA polymerase beta. The inhibition by the sulfolipids was concentration dependent, and almost complete inhibition of DNA polymerase alpha and DNA polymerase beta was achieved at 6 and 8 microg/mL, respectively. The compounds did not influence the activities of calf thymus terminal deoxynucleotidyl transferase, prokaryotic DNA polymerases such as the Klenow fragment of DNA polymerase I, T4 DNA polymerase and Taq polymerase, the DNA metabolic enzyme DNase I, and even a DNA polymerase from a higher plant, cauliflower. Similarly, the compounds did not inhibit the activity of the human immunodeficiency virus type 1 reverse transcriptase. The kinetic studies of the compounds showed that DNA polymerase alpha was inhibited non-competitively with respect to the DNA template and substrate, whereas DNA polymerase beta was inhibited competitively with both the DNA template and substrate. The binding to DNA polymerase beta could be stopped with non-ionic detergent, but the binding to DNA polymerase alpha could not.

Animals↗
PubMed1998

Age-dependent accumulation of heavy metals in baikal seal (Phoca sibirica) from the Lake Baikal.

Concentrations of Fe, Mn, Zn, Cu, Cd, and Hg were determined in the liver, kidney, and muscle of 60 Baikal seals collected from Lake Baikal in 1992 to investigate age-dependent accumulation. Among essential elements, Fe concentrations in the muscle, liver, and kidney increased with age, suggesting development of diving ability. The concentrations of Mn, Zn, and Cu decreased with age, especially at immature stages. Toxic elements such as Hg and Cd decreased in adult males and thus the male-female difference was clearly observed in their concentrations, which differed from patterns usually found in marine mammals. Such accumulation patterns were due to difference in the feeding rates between males and females under low exposure to Hg and Cd. In addition, a greater excretion of Hg than that of Cd through molting and parturition was estimated.

Aging↗
PubMed1998

Inhibition of the neuronal nicotinic receptor-mediated current by kappa opioid receptor agonists in PC12 cells.

The authors studied effects of opioid receptor agonists on neuronal nicotinic-receptor-mediated current in PC12 cells using whole-cell current recording. At 1 microM, [d-Ala, N-Me, Phe, Gly-ol]- enkephalin (DAMGO), a selective micro receptor agonist, or 10 microM methionine-enkephalin, a micro and delta receptor agonist, did not inhibit the current elicited by 30 microM nicotine significantly. Dynorphin A (1-17) (0.1-1 microM), an endogenous kappa receptor agonist, and U50488 (0.1-10 microM), a non-peptide selective kappa receptor agonist, depressed the nicotine-induced current reversibly in a dose-dependent manner. They accelerated the current decay, resulting in greater effects on the non-desensitized current than the peak current. These effects were not affected by nor-binaltrophimine, a selective kappa receptor antagonist, or by inclusion of guanosine 5'-O-(2-thiobiphosphate) (GDP[beta-S]), a GTP binding protein blocker, into the pipette solution. These results demonstrate that two kappa opioid receptor agonists, dynorphin A (1-17) and U50488, inhibit neuronal nicotinic-receptor-mediated current without the involvement of opioid receptors or GTP binding proteins. The acceleration of the current decay suggests a direct action on nicotinic receptors such as open channel block, or augmentation of desensitization. Modulation of neuronal nicotinic receptors by dynorphins may play a role in some areas where dynorphin release sites and neuronal nicotinic receptors are colocalized.

3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cycloh↗
PubMed1998

Isolation and radiation hybrid mapping of dinucleotide repeat polymorphism at the human matrix Gla protein (MGP) locus.

Matrix Gla protein (MGP) is an 84-residue, vitamin K-dependent protein expressed by chondrocytes and vascular smooth muscle cells, and is a potent regulator of calcium deposition in cartilage and arterial wall. We isolated a polymorphic dinucleotide CA repeat marker from a genomic clone containing the human MGP gene. This polymorphism will be useful in genetic studies of arteriosclerosis and osteoporosis.

Alleles↗
PubMed1998

Isolation and radiation hybrid mapping of a dinucleotide repeat polymorphism at the human calcium-sensing receptor (CASR) locus.

Calcium-sensing receptor (CASR) in parathyroid gland regulates calcium homeostasis by sensing decreases in extracellular calcium levels and effecting an increase in secretion of parathyroid hormone. A polymorphic dinucleotide (CA) sequence was isolated from a genomic clone containing the human CASR gene and was mapped to 3q13.3-q21. This polymorphism will be useful in the genetic study of disorders affecting calcium metabolism, such as hypercalcemia, hypocalcemia, osteoporosis, hyperparathyroidism, and hypoparathyroidism.

Alleles↗
PubMed1998

Adhesiveness of AcrySof to a collagen film.

PURPOSE: To measure the adhesiveness of the AcrySof intraocular lens (IOL) to a collagen film to ascertain its capacity to adhere to the lens capsule. SETTING: Haibara General Hospital, Haibara, and Hamamatsu University School of Medicine, Hamamatsu, Shizuoka, Japan. METHODS: Each of five AcrySof IOLs was attached to a collagen film, slightly pressed in intraocular irrigating solution, and then pulled up and off the film with a DuNouy's surface balance. The force recorded by the surface balance at the moment it detached from the film was defined as the lens' adhesiveness. A control experiment was performed using five conventional poly(methyl methacrylate) (PMMA) IOLs. RESULTS: Mean adhesiveness was 2.76 gram-weight (gw) +/- 0.55 (SD) for AcrySof and 0.81 +/- 0.20 gw for PMMA. The difference was statistically significant (P < .0001, t-test). CONCLUSION: AcrySof may have a strong tendency to adhere to the lens capsule, contributing to posterior and anterior capsule clarity and preventing lens decentration in vivo.

Acrylates↗
PubMed1998

Effects of pre- and postnatal protein deprivation on rat's hard palatine mucosae: a scanning electron microscopic study of the connective tissue papillae.

The primary (connective tissue papillae) and secondary projections of the subepithelial connective tissue of the lamina propria were studied in the hard palate of normal (control group), and in protein-deficient pups (experimental group) obtained through maternal protein deprivation during pregnancy and lactation. At birth, the primary projections in the control group are more developed in width whereas in the experimental group they are thin with a crest-like shape. On day 7 of lactation, the primary projections are abundant, well developed and regularly arranged in the control group. They are few in number and are irregular in shape and disposition in the experimental group. The secondary projections are located posterior to the primary ones in the control group and are intercalated with them in the experimental group. On day 21 of lactation, the characteristic foliate aspect of the primary projections are noted in the control group. In the experimental group they remain thin with a crest-like aspect.

Animals↗
PubMed1998

Successful prenatal exclusion of an unspecified subtype of severe epidermolysis bullosa.

BACKGROUND: In most cases of prenatal diagnosis of epidermolysis bullosa (EB), the subtype of severe EB from which the fetus is at risk is identified by studying the specimens of the proband. In this study, the parents of a child with an unspecified subtype of severe EB sought prenatal diagnosis for their second and third pregnancies. METHODS: The firstborn of a couple (the proband) suffered generalized blistering and erosions of the skin present from delivery, and died on the 11th postnatal day of severe EB of an unspecified type. The only diagnostic specimen available from the first infant was a conventionally stained skin section for light microscopy that showed the dermo-epidermal separation. For prenatal diagnosis in the second and third pregnancies, fetal skin biopsies were performed at 19 weeks of gestation. RESULTS: In both cases, fetal skin showed no ultrastructural abnormalities and no evidence of dermo-epidermal separation. Indirect immunofluorescence was positive for monoclonal antibodies against type VII collagen, laminin 5, uncein, alpha6 and beta4 integrins, BPAG2, and HD1/plectin, which are known to be reduced or absent in specific subsets of severe EB. The pregnancies were therefore continued, and normal healthy second and third children were delivered. CONCLUSIONS: Fetal skin biopsy, together with a panel of newly developed monoclonal antibodies, provided reliable prenatal diagnosis in the present family in which preliminary information of the EB proband was limited.

Biopsy↗
PubMed1998

Apoptosis in cellular compartments of rat spinal cord after severe contusion injury.

Following a controlled, severe contusion lesion to the lower thoracic spinal cord in adult rats, we found that apoptosis occurred in cells located in both gray and white matter. This suggested that both nonneuronal cells, including astrocytes, oligodendroglia and microglia, as well as neurons, might participate in programmed cell death (PCD) following spinal cord injury (SCI). Determination of which cell populations participate, and the kinetics and extent of their involvement might reveal new paradigms for approaches to therapy. Consequently, we assessed the functional deficit, comparing a comprehensive locomotor rating scale (LRS) with the inclined plane test at various times after injury. Using standard histology, along with cell-specific markers, we assessed PCD in different spinal cord segments using several parameters of apoptosis. Our results indicate that hind limb motor function was lost at day 1, and then only gradually and ineffectively (about 10-15%) recovered over the next month. Evidence for increased cell number was present for astrocytes and microglia beginning at day 1 after injury. Over the postinjury time period, apoptotic cells appeared (from day 1 to 14), and peaked (in terms of apoptotic index) on day 3. About one-third were microglia, whereas neurons, both large and small, also underwent apoptosis, again peaking at day 3. However, neurons continued to die and were not replaced by proliferation, so that at day 7, three times as many neurons (as a percentage) underwent PCD compared with the glial compartment. Oligodendrocytes also underwent apoptosis, with a biphasic curve, both at days 3 and 14 following injury. Thus, in addition to immediate, passive necrosis, delayed and apoptotic PCD also occurred in all cell populations in severely injured spinal cord.

Animals↗
PubMed1998

Analysis of neurofibromatosis type 1 gene mutation in juvenile chronic myelogenous leukemia.

The neurofibromatosis type 1 (NF1) gene has been considered to be a tumor suppressor gene, since the NF1 gene product downregulates the ras oncogene product (p21(ras)). In addition, children with NF1 show an increased incidence of myelogenous leukemia, including juvenile chronic myelogenous leukemia (JCML). We studied 8 Japanese JCML patients without NF1 for mutations in exons 21-36 of the NF1 gene by using polymerase chain reaction/single-strand conformation polymorphism analysis. This region was chosen because it includes two main hotspots in the NF1 gene as well as the functionally important domain, GTPase-activating protein-related domain, which mediates the downregulation of ras activity. One of the 8 JCML patients exhibited a G to T transversion at the third nucleotide of the codon GAG for Glu at amino acid residue 1699, which results in the heterozygous conversion to Asp (E1699D). This variation was detected neither in 65 healthy volunteers nor 50 NF1 patients. No other variations were detected in our JCML patients. We suggest that NF1 gene mutation does not occur frequently in JCML without NF1.

Female↗