Biomedical subjects

T Handa

Publications and source records attributed to T Handa.

At least 37 records · Page 2Linked to original sources

PubMed1999

[The Hungarian translation of the "Dental Fear Survey" based on the Hungarian population].

Authors translated the "Dental Fear Survey" (DFS) into Hungarian. 196 persons have been investigated and the DFS values have been compared to DAS, STAI-S, STAI-T values. Mean values were: DFS: 46.27; DAS: 12.24; STAI-S: 41.58; STAI-T: 42.68. Authors found all values higher in the case of women comparing to men. Positive correlation has been found between DAS and DFS, but STAI-S and STAI-T increased only moderately comparing to the DAS and DFS values.

Adolescent↗

PubMed1998

Surface composition regulates clearance from plasma and triolein lipolysis of lipid emulsions.

Sphingomyelin (SM) and cholesterol (Chol) are major surface lipid constituents of plasma lipoproteins. We investigated the effects of SM and Chol on the plasma clearance of lipid emulsions as a model for lipoprotein particles in rats. The presence of Chol facilitated the removal of emulsion particles from plasma, whereas SM delayed particle removal. Preinjection of lactoferrin, an inhibitor of the apolipoprotein E (apoE) receptor, revealed that the differences in clearance of emulsions were due to the differences in affinity for the apoE receptor. Measurement of apolipoprotein binding suggested that the balance of apoE and apoC (apoC-II and apoC-III) bound to emulsions caused the difference in plasma clearance of emulsion particles. That is to say, SM in the emulsion surface decreased binding of apoE, which led to a longer circulation of emulsion particles in plasma. Chol, on the other hand, decreased the ratio of apoC to apoE, which may have promoted emulsion uptake through the apoE receptor. We also examined in vitro lipolysis using immobilized lipoprotein lipase (LPL) in a heparin affinity column. Lipolysis rates were significantly reduced by the incorporation of SM into the emulsion surface, but not by the incorporation of Chol, indicating that SM in the lipoprotein surface is an important lipid component regulating LPL-mediated lipolysis. Our results suggest that the presence of SM and Chol in the lipoprotein surface plays an important role in the circulation behavior and LPL-mediated lipolysis of lipid emulsions through their effect on the selectivity of plasma protein binding.

Animals↗

PubMed1998

Sjögren-Larsson syndrome: postmortem brain abnormalities.

Brain abnormalities were described in a patient who had experienced Sjogren-Larsson syndrome (SLS) with typical clinical signs. Examination of the brain revealed (1) accumulation of peculiar lipoid substances stained lightly with periodic acid-Schiff (PAS) in the subpial, subependymal, and perivascular glial layers, the subpial and perivascular spaces, and the white matter of the cerebrum and brainstem; (2) proliferation of perivascular macrophages containing lipofuscin-like pigments; (3) dense distribution of round or ellipsoid small bodies stained strongly with PAS in the subpial, subependymal, and perivascular glial layers and the white matter; (4) appearance of spheroid bodies in the neuropil of relay nuclei (the lateral geniculate body, pontine nuclei, inferior olivary nucleus, posterior funicular nucleus, and dentate nucleus) and the white matter; and (5) reduction of myelinated nerve fibers in the cerebral and cerebellar white matter. Six-layered neuronal cytoarchitecture was preserved in the cerebral neocortex, except for the insula where pyramidal neurons were arranged at random. The exact mechanisms remain unclear, but it is suggested that peculiar lipoid substances may accumulate in the specific regions of the brain and that neuronal and astrocytic processes may be primarily affected in SLS.

Brain↗

PubMed1998

Gap junction change in supporting cells of the organ of Corti with ryanodine and caffeine.

It has been demonstrated that the gap junctions of the supporting cells of the organ of Corti are controlled by H+ and Ca2+. Inside these cells there is a tubular structure. It is supposed that this network is endoplasmic reticulum. Calcium release from inside the cells, and the effect of calcium on the gap junctions of these cells, were investigated under whole cell clamping application of ryanodine and caffeine. Membrane capacitance and membrane resistance were calculated, with corrections for changes in whole cell parameters. Ryanodine-treated cells (1 microM-10 mM), caffeine-treated cells (5 mM 500 nM) and A23187-treated cells were uncoupled at their gap junctions. Therefore, Ca2+ plays a role in the uncoupling of the gap junctions in supporting cells of the organ of Corti from inside the cells.

Animals↗

PubMed1998

Study of rapidity and quality for the VITEK susceptibility cards with 45 wells.

VITEK 45 wells Card was evaluated. Recent clinical isolates of gram-positive cocci (107) and gram-negative bacilli (179) were antimicrobial susceptibility testing by VITEK system in comparison with MIC-2000 system. The antimicrobial susceptibility results were available within of 8 h for gram-positive cocci without a part of MRSA. Enterobac-teriaceae were available within of 8 h and Pseudomonas aeruginosa were from 8 to 11 h. The antimicrobial susceptibility data had disagreement of 60% with EM, 46% with CLDM for Enterococcus faecium, 50% with CMZ for Citrobacter freundii, and 71% with CTM for Morganella morganii, whereas it was satisfactory agreement of 97.5% for gram-positive cocci and 98.2% for gram-negative bacilli. In using this procedure it was possible to provide accurate and rapid results of anti-microbial susceptibility tests for all organisms.

Enterobacteriaceae↗

PubMed1998

Effects of sphingomyelin and cholesterol on lipoprotein lipase-mediated lipolysis in lipid emulsions.

Lipoprotein lipase (LPL) hydrolyzes triacylglycerol (TG) of TG-rich lipoproteins. We investigated the effects of sphingomyelin (SM) and cholesterol (Chol) on the lipolysis of lipid emulsions by LPL using human apolipoprotein C-II (apoC-II) or plasma as an activator. Kinetic studies of the lipolysis rates clearly demonstrated that the primary effect of the activator on the LPL reaction was not to increase the affinity of LPL for the emulsion surface, but to enhance LPL catalytic activity. Incorporation of SM into the emulsion surface caused increases in Km(app) and decreases in Vmax(app), indicating that SM inhibited lipolysis by decreasing both affinity for substrates and catalytic activity of LPL. SM was also found to affect possible factors related to the lipolysis rates; that is, SM increased TG solubility in surface layers and decreased apoC-II binding to the emulsion surface. Interestingly, Chol did not affect the lipolysis rates even though it decreased TG solubility and apoC-II binding. These results indicated that neither TG solubility nor amount of apoC-II binding were determinate factors in LPL-mediated lipolysis under physiological conditions. Our results suggest that the content of SM in the lipoprotein surface plays an important role by controlling lipoprotein lipase-mediated lipolysis, and that cholesterol enrichment in the lipoprotein surface has no influence on lipolysis, but may affect other metabolic processes such as uptake by the liver through the selectivity of apolipoprotein binding.

Apolipoprotein C-II↗

PubMed1998

[Two cases of subarachnoid hemorrhage associated with neurofibromatosis type I: a case of multiple cerebral aneurysms and arteriovenous malformation, and another case of an anterior communicating artery aneurysm].

Two cases of subarachnoid hemorrhage associated with neurofibromatosis type I (von Recklinghausen's disease) are reported. A 30-year-old male patient (case 1) had been diagnosed as having neurofibromatosis type I due to neurofibroma and café-au-lait spot. He suffered from subarachnoid hemorrhage and angiography showed multiple aneurysms in the right and left middle cerebral arteries and left internal carotid artery. He also had arteriovenous malformation in the left temporal lobe. Case 2 was that of a 62-year-old female patient with neurofibroma and café-au-lait spot. She suffered from subarachnoid hemorrhage and angiography showed an aneurysm in the anterior communicating artery. Both patients were discharged with no deficits after neck clipping, however they both suffered from large-sized hematoma in the punctured site of the femoral artery after angiography. The cerebral aneurysms associated with neurofibromatosis type I are often multiple and may coexist with arteriovenous malformation.

Adult↗

PubMed1997

Effects of hydrostatic pressure on matrix synthesis and matrix metalloproteinase production in the human lumbar intervertebral disc.

STUDY DESIGN: This study is a unique in vitro study on the effects of hydrostatic pressure on human intervertebral disc metabolism. OBJECTIVE: To investigate the effects of hydrostatic pressure on matrix synthesis and matrix metalloproteinase production in the human lumbar intervertebral disc. SUMMARY OF BACKGROUND DATA: Mechanical stress and hydrostatic pressures influence proteoglycan and protein synthesis rates in bovine articular cartilage and coccygeal discs. However, the mechanism of matrix synthesis regulation of the intervertebral disc under mechanical stress has not been elucidated. METHODS: Twenty-eight human lumbar intervertebral discs obtained from surgery and from cadavers at autopsy were used. Each tissue fraction was charged with medium in a plastic syringe and placed in a water-filled hydrostatic pressure-control vessel. The hydrostatic pressures applied were 1 (control), 3, and 30 atm (atm = atmospheres) for 2 hours. The proteoglycan and protein synthesis rates were determined by radioisotope incorporation. The production of matrix metalloproteinase-3 and tissue inhibitor of metalloproteinases-1 were measured by a one-step enzyme immunoassay method using monoclonal antibodies. RESULTS: Three atm pressure stimulated proteoglycan synthesis rates in the nucleus pulposus and inner anulus (n = 14 in each tissue). Compared with the control group, 30 atm pressure significantly inhibited proteoglycan synthesis in the inner anulus (P = 0.011). In the nucleus pulposus, matrix metalloproteinase-3 production was stimulated at a pressure of 30 atm relative to 3 atm (P = 0.014, n = 16 in each tissue). The highest tissue inhibitor of metalloproteinases-1 production showed highest values at 3 atm pressure in the inner anulus (n = 16 in each tissue). CONCLUSION: The results suggest that hydrostatic pressure influences intervertebral disc cell metabolism. A physiologic level of hydrostatic pressure (3 atm) may act as an anabolic factor for stimulation of proteoglycan synthesis and tissue inhibitor of metalloproteinases-1 production. This may be essential for maintaining the matrix of the disc. If the pressure was 30 atm or more or 1 atm or less, a catabolic effect will be predominant, with reduction of proteoglycan synthesis rate and increase of matrix metalloproteinase-3 production. Abnormal hydrostatic pressure, therefore, may accelerate disc degeneration.

Cadaver↗

PubMed1997

Suppressive effects of salts on droplet coalescence in a commercially available fat emulsion during freezing for storage.

To assess possible improvements in the practical use of long-term freezing storage for commercially available fat emulsions, the effects of salts on coalescence (fusion) of emulsions during freeze-thawing cycles were studied. For this purpose, apparent size changes were measured by dynamic light scattering, and the dispersed droplets were directly observed by freeze-fracture electron microscopy before and after the freeze-thawing processes. Intravenous high-calorie nutrient fluid, based on soybean oil in water (2.2 wt% glycerin) and emulsified by egg phosphatides, was selected as a representative commercially available fat emulsion. Possible mechanisms of the suppressive effects of various salts (Li, Na, K, Rb, and Cs chlorides) on coalescence during repeated freezing with liquid nitrogen and subsequent thawing were examined in terms of the zeta-potential of the emulsion droplets and differential scanning calorimetry heating curves of the water-salt-glycerin ternary solution. The suppressive effects of salts on the coalescence of the emulsion droplets during freeze-thaw cycles could be ascribed to the suppression of ice crystal formation and the condensation of the droplets in unfrozen aqueous channels between the ice crystals during the freezing cycle.

Calorimetry, Differential Scanning↗

PubMed1997

A double-muscle transfer using a divided rectus femoris muscle for facial-paralysis reconstruction.

There are two types of smiling: without exposure of the teeth (usual smile), and with their exposure (square smile). Performance of the former involves use of the major zygomatic muscle, while the latter is created by the major zygomatic and the depressor labii inferior muscles. The function of the depressor labii inferioris muscle cannot be ignored in facial paralysis reconstruction. A double-muscle transfer using a divided rectus femoris muscle for one-stage reconstruction of both the major zygomatic muscle and the depressor labii inferior muscle is described. The patient suffered facial paralysis caused by an extracranial schwannoma originating from the facial nerve. After the tumor was removed, divided rectus femoris muscle segments were transferred to reconstruct the major zygomatic muscle and the depressor labii inferior muscle. After the pedicle vessel of the muscles was anastomosed to the recipient facial vessel, the long motor nerve of the proximal divided muscle was cross-faced and coapted directly to the prepared contralateral buccal branch. The short motor nerve of the distal muscle segment was sutured to the ipsilateral masseteric nerve. The advantages of divided rectus femoris muscle transfers are that (1) independent muscle contraction can be reconstructed; (2) no tongue or trapezius muscle atrophy occurs because the masseteric nerve is used as the motor source of the labial depressor; (3) only one muscle is sacrificed for muscle grafts; and (4) it is a one-stage reconstruction.

Adult↗

PubMed1997

A full-thickness chondrocutaneous flap from the auricular concha for repair of tracheal defects.

A free full-thickness chondrocutaneous flap from the auricular concha for the repair of large tracheal defects was transferred successfully. The flap is based on the superficial temporal vessels (reversed flow) and the posterior auricular vessels. The advantages of this flap for the repair of tracheal defects are (1) its dissection is easy, (2) thin components of the flap provide a wide postoperative airway, (3) the structure of the reconstructed trachea is made firm by the conchal cartilage with vascularization, (4) the highly vascularized cartilage results in less resorption than a free cartilage graft, (5) the donor site can be repaired easily and is concealed by the remnant auricle, and (6) a long arterial pedicle (reversed flow) can be obtained. The disadvantages are (1) there may be temporary postoperative congestion of the flap, (2) postoperative narrowing of the auriculocephalic sulcus may occur, and (3) a short venous pedicle often requires a vein graft.

Adult↗

PubMed1997

Evaluation of particulate embolic materials with MR imaging, scanning electron microscopy, and phase-contrast microscopy.

PURPOSE: To analyze the properties and embolic effect of microfibrillar collagen (MFC), Gelfoam powder, and polyvinyl alcohol (PVA) materials that are used in embolization procedures in the head and neck. METHODS: The shape and surface of these embolic agents were examined with scanning electron microscopy and phase-contrast microscopy. The mean number of areas of T2-weighted high signal intensity was measured on MR images in a rat embolization model to estimate the embolic effect. RESULTS: By scanning electron microscopy and phase-contrast microscopy, MFC appears fibriform and has various sizes and an irregular surface. Gelfoam is of uniform size and has a smooth surface. PVA materials are granulated and have a rough surface. MFC is somewhat suspendable and its shape changes moderately after suspension. Gelfoam is very suspendable and its shape changes rapidly. PVA showed only mild swelling. The embolic effect of MFC was the lowest of the materials examined. Large PVA particles (250 to 500 microns) showed a lesser embolic effect than Gelfoam or small PVA particles (50 to 150 microns) or medium-sized PVA particles (150 to 250 microns). No significant differences were observed among the embolic effects of Gelfoam, small PVA particles (50 to 150 microns), and medium PVA particles (150 to 250 microns). CONCLUSIONS: MFC and large PVA particles (250 to 500 microns) should be used for embolization of vascular anatomy involving potentially dangerous anastomoses. Gelfoam, PVA particles of 150- to 250-micron diameter, and PVA particles of 50- to 150-micron diameter are adequate for embolization involving homogeneous and peripheral anatomy.

Animals↗

PubMed1997

Effect of cholesterol on apolipoprotein A-I binding to lipid bilayers and emulsions.

The effects of cholesterol (Chol) on the interaction of apolipoprotein A-I (apoA-I) with phospholipid bilayer vesicles and lipid emulsions were investigated. ApoA-I bound to phosphatidylcholine (PC) vesicles with higher affinity and lower capacity compared to triglyceride-PC emulsions. An increase in surface Chol in triglyceride-PC emulsions decreased the binding capacity without changing the binding affinity. In contrast, addition of Chol to PC vesicles caused a marked increase in capacity and decrease in affinity for apoA-I binding. ApoA-I caused a large release of entrapped aqueous dye, calcein, from PC vesicles, whereas this apoA-I-induced leakage was relatively small in the vesicles containing Chol. The incorporation of phosphatidylethanolamine into the vesicles also exerted effects similar to those of Chol on apoA-I binding and calcein leakage. The shifts of fluorescence emission maximum of dansyl lysine, probing the surface region of membranes, indicated that Chol as well as phosphatidylethanolamine increased the headgroup space of the vesicles. The binding maximum of apoA-I was closely correlated with the emission maximum of dansyl lysine, not with the fluorescence anisotropy of I-[4-(trimethylamino)phenyl]phenylhexatriene, suggesting that the binding capacity of apoA-I to the bilayer surface was modulated by the headgroup space rather than the acyl chain fluidity. These results show that Chol affects the bilayer surface so as to allow more apoA-I to bind to bilayers and may suggest the possibility of the interaction of apoA-I with Chol-enriched membrane domains.

Animals↗

PubMed1996

Physical states of surface and core lipids in lipid emulsions and apolipoprotein binding to the emulsion surface.

Plasma triglyceride-rich lipoproteins vary in lipid composition during their metabolism. We investigated the effects of the lipid composition of emulsion particles, specifically those of cholesterol enrichment and core replacement (replacing core triglyceride with cholesteryl oleate), on the physical states of surface and core lipids. Steady-state and time-resolved fluorescence anisotropies were measured in lipid emulsions using 1,6-diphenylhexatriene to probe the core and 1,6-diphenylhexatriene analogues for the outer and inner hydrophobic portions of surface phospholipids. In the absence of cholesterol, core replacement had little effect on the surface rigidity, despite the large difference in core mobility. However, core replacement caused a marked increase in surface rigidity in the presence of cholesterol. Quenching experiments using the fluorescent cholesterol analogue, dehydroergosterol, indicated that core replacement allowed surface dehydroergosterol to redistribute from the inner to the outer regions in the emulsion surface. These results indicated that core replacement modulates the surface properties of the emulsion particles through the redistribution of cholesterol in the surface layers. Furthermore, core replacement significantly decreased the binding of apolipoprotein E to the emulsion surface, whereas the binding of apolipoprotein CII responded to the cholesterol enrichment. This binding behavior of exchangeable apolipoproteins may closely correlate with the location of surface cholesterol and the mobility of core lipids.

Apolipoproteins↗

PubMed1996

Brain dysplasia associated with Larsen-like syndrome.

We present an autopsy case of Larsen-like syndrome with unusually severe neurologic complications. The patient, a 3-year-old girl, manifested severe psychomotor retardation, tetraplegia, and intractable partial seizures as well as multiple joint dislocations with other skeletal deformities, minor external anomalies, and laryngotracheomalacia. Neuropathological examination of the brain revealed (1) cortical dysgenesis in the bilateral perisylvian region; (2) protrusions of the brain parenchyma into the subarachnoid space, (3) abnormal arrangement of olivary neurons, (4) dilation of the lateral ventricles with subventricular gliosis and multiple glial nodules, (5) hypoplasia of the cerebral white matter with subcortical astrocytosis, and (6) necrotic change in Sommer sector of the hippocampus. There were no microscopic abnormalities in the mesenchymal tissue of the brain (i.e., vascular walls and the meninges). Cortical dysgenesis in the perisylvian region was characterized by a zonal heterotopia of pyramidal and granule neurons in the molecular layer, which clinically may be closely related to intractable partial seizures in the orofacial area. Findings 1, 2, and 3 may represent a disturbance of neuroblast migration, speculated to have occurred during the latest stage of migration (around 20-25 weeks gestation). There are few published reports describing the combination of Larsen-like syndrome and brain dysplasia. Correlation of brain dysplasia with congenital skeletal abnormalities is unclear in our patient. We speculate that systemic hypoxic-ischemic insults during the second half of gestation and/or some genetic factors might be possible causes of brain dysplasia.

Abnormalities, Multiple↗

PubMed1996

No effect of high-protein food on the stereoselective bioavailability and pharmacokinetics of verapamil.

The effects of high-protein food on the bioavailability of both the racemate and individual enantiomers of verapamil were investigated in 12 healthy volunteers using a randomized crossover design. Food had no effect on any parameter of bioavailability for both the racemate and the individual enantiomers of verapamil except time to maximum concentration (tmax), which was significantly prolonged after food intake. The pharmacokinetics of the enantiomers of norverapamil were not significantly changed by food intake. These results suggest that high-protein food does not alter the pharmacokinetics and bioavailability of either the racemate or the individual enantiomers of verapamil. Therefore, the clinical efficacy of verapamil is not related to food intake, except for a slight prolongation in the time to onset of the pharmacologic effects. The present data can be applied to the high-protein content meal intake.

Administration, Oral↗

PubMed1996

[Pathological evaluation of superselective one-shot intra-arterial infusion chemotherapy for head and neck tumors].

Since 1992, we have treated 43 patients with head and neck tumors by superselective intra-arterial infusion chemotherapy (SIIC) via femoral artery. In 8 patients among then, operation was performed thereafter with/without radiation therapy (RT). CDDP and/or CBDCA were utilized as the chemotherapeutic modality. Only SIIC or RT showed Grade (Gr.) 0-2b pathological effects on Oboshi-Shimosato classification scheme, while a combination of SIIC and RT exhibited Gr. 2b-4 pathological effects. We conclude that a combination of SIIC and RT was most effective and had induced degeneration or necrotic changes in the tumor tissue.

Adult↗

PubMed1995

Superselective cisplatin (CDDP)-carboplatin (CBDCA) combined infusion for head and neck cancers.

A group of 26 patients with carcinoma of the head and neck region was treated by superselective intra-arterial infusion of cisplatin (CDDP)-carboplatin (CBDCA). The tumor locations included the tongue (n = 4), oral base (n = 2), nasopharynx (n = 2), oropharynx (n = 8), hypopharynx (n = 4) and larynx (n = 4). Using the coaxial technique, a microcatheter was placed in the lingual, ascending pharyngeal, facial and superior thyroidal arteries according to the location of the tumor. Under imaging studies, CDDP (50 mg/m2)-CBDCA (300 mg/m2) was infused into the vessel, via injectors at the rate of 12.5 ml/min. One to five injections were given every 4 weeks. During and following the chemotherapy the patients received radiotherapy (n = 22), surgery (n = 4) or both (n = 3). Sixty-six sessions of intra-arterial chemotherapy were given with no major complications. Drug-related systemic side effects were mild. The overall response rate was 96% (complete response (CR) 50% and partial response (PR) 46%). Superselective CDDP-CBDCA combined infusion is feasible, relatively non-toxic, and important as multimodality therapy.

Adult↗