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Biomedical subjects

Y Seki

Publications and source records attributed to Y Seki.

At least 73 records · Page 4Linked to original sources
PubMed1998

Benign fibroosseous lesions involving the skull base, paranasal sinuses, and nasal cavity. Report of two cases.

The authors report two patients with benign fibroosseous lesions involving the center of the skull base: a 15-year-old boy with repetitive meningitis and pneumocephalus and a 11-year-old boy with nasal obstruction and headache. The clinical diagnoses were ossifying fibroma and aneurysmal bone cyst, respectively. Lesions in both patients extended to the nasal cavity, the sphenoid and posterior ethmoid sinuses, and the skull base, where the planum sphenoidale, the sella turcica, the upper two-thirds of the clivus, and the medial portion of the middle cranial base were involved. The lesions were totally removed using an anterior craniofacial approach. Characteristics of these lesions and the surgical approach are discussed.

Adolescent↗
PubMed1998

[Hemostatic evaluation of a patient with haloperidol-induced neuroleptic malignant syndrome associated with disseminated intravascular coagulation].

A 94-year-old man who had been admitted to our hospital for the treatment of senile dementia and restless behavior exhibited consciousness disturbances, acute respiratory failure, high fever, and thrombocytopenia the day after receiving haloperidol as prescribed by a psychiatrist. On the fourth day following administration of haloperidol, acute renal failure with rhabdomyolysis and disseminated intravascular coagulation (DIC) developed in the patient, who was accordingly given a diagnosis of haloperidol-induced neuroleptic malignant syndrome (NMS) associated with DIC. He was then given heparin and antithrombin III, and his DIC symptoms improved soon thereafter. Elevated plasma levels of tissue factor and tumor necrosis factor-alpha (TNF-alpha) were sustained during this therapy course. Other cytokines, including interleukin IL-1 beta, IL-2 and IL-6, were not elevated. There are activation of extrinsic coagulation and an elevated level of TNF-alpha during acute renal failure and rhabdomyolysis associated with NMS, which is thought to trigger the onset of DIC.

Acute Kidney Injury↗
PubMed1997

New method for incorporating solvent influence into the evaluation of X-ray scattering intensity of proteins in solution.

A new method, the surface integration method, is presented for taking into account the influence of solvent on the intensity of X-ray scattered from proteins in solution. It requires no averaging numerically over the solute orientation. The solvent is modeled by a continuous medium with electrons of uniform density. This method is applied to amino acids, peptides and native proteins to confirm its effectiveness. The solvent influence on the normalized scattering intensity I(K) I(0) is more noticeable for larger solutes and at larger scattering angles, where I(K) is the intensity of scattered X-ray with the magnitude of scattering vector K.

Journal Article↗
PubMed1997

A multiparametric analysis of occlusal and periodontal jaw reflex characteristics in young adults with normal occlusion.

Periodontal jaw reflex, duration of percussion sounds, tooth mobility, and time-moment analysis of occlusal contacts by the T-scan system was recorded in nine periodontally healthy volunteers. The results showed that (i) reflex responses to the pressure applied to the uppercentageral incisors in the lingolabial direction varied, depending on the background jaw-clenching force (BCF) of the same-sided first molars. The BCF levels to elicit excitatory reflexes were 6-8 Kgf, and inhibitory reflexes were clearly elicited with a BCF of 10 Kgf and beyond. (ii) Duration of percussion sounds via an occlusal sound analyser (4.73-4.84 mS: upper first molars, 4.89-5.00 mS: uppercentageral incisors) and tooth mobility using a 'Periotest' (3.3-3.5: upper first molars, 5.5-5.6: uppercentageral incisors) showed a normal value. (iii) The time moments of occlusal contacts were symmetrical toward the midsagittal axis of the occlusal plane. The centre of the anteroposterior occlusal contacts was located in the first molar regions.

Adult↗
PubMed1997

Plasma levels of thrombomodulin and lipoprotein (a) in patients with cerebral thrombosis.

To evaluate the clinical implications of soluble thrombomodulin and lipoprotein (a) [Lp(a)] in patients with cerebral thrombosis, these parameters were measured in the plasma of 28 patients with cerebral thrombosis within 3 days of onset, 36 with cerebral thrombosis more than 1 month after onset, six with cerebral hemorrhage more than 3 months after onset and 37 healthy volunteers. In the patients with chronic-phase cerebral thrombosis, the thrombomodulin and Lp(a) levels were significantly higher and the total cholesterol level was significantly lower than in the normal group, while the patients with acute-phase cerebral thrombosis had significantly lower total cholesterol levels. The plasma level of Lp(a) in acute-phase cerebral thrombosis, but not that of thrombomodulin, was significantly higher in thromboses located in the cortex area and in patients with recurrent attacks than in the normal controls. There were no significant differences in thrombomodulin, Lp(a) or total cholesterol levels between the chronic-phase cerebral hemorrhage and normal groups. These findings support the hypothesis that Lp(a) plays a part as a risk factor in cerebral thrombosis, especially in patients with a cortex area thrombosis and in patients with a recurrent attack. The high levels of thrombomodulin in the chronic-phase cerebral thrombosis group suggests the presence of continuous endothelial cell damage.

Adult↗
PubMed1997

Fitness of a gas mask for the face of a worker handling organic solvents.

The fitness of the half facepiece of a gas mask to the face of a worker handling organic solvents was evaluated through the quantitative determination of the concentrations of both organic solvent vapors and airborne dust inside and outside the facepiece. Leakage rates for dust were measured using a mask-fitting tester on a facepiece with a dust filter-covered respirator cartridge of organic solvents. The same facepiece was evaluated for the leakage rate for organic solvent vapors through the determination of the concentrations of the air inside and outside the facepiece. Highly significant correlations were found between the leakage rates obtained for dust and those for organic solvent vapors. The leakage rates for organic solvents were found to be slightly higher than those for dust. The present finding suggested that the leakage of organic solvent vapors from the interstice between the facepiece of gas masks and workers' faces can be evaluated using the leakage rate for dust for the same facepiece of the gas mask attached with the cartridge covered with a high efficiency particulate air (HEPA) filter.

Dust↗
PubMed1997

A simple method for carbon disulfide monitoring using a diffusive sampler, thermal desorption and a stain tube.

A simple sampling and analytical method for monitoring carbon disulfide (CS2) vapor was investigated to assess exposure to low levels of CS2 in a viscose rayon factory. CS2 vapor was adsorbed on polymer beads (poly (2,6-diphenyl-p-phenylene oxide)) packed in a diffusive sampling tube. The sampling tube was heated at 180 degrees C for 7 min using a Daily Exposure Limit Test Apparatus, and thermally desorbed CS2 was measured by a stain tube for CS2. In laboratory experiments, the indicated CS2 levels measured by this method were highly correlated with calibrated CS2 concentrations (1-40 ppm), exposure duration (1-8 hr) and cumulative exposure levels. The CS2 values were stable up to 7 days after sampling when the diffusive tubes were stored at 4 degrees C and 20 degrees C. The effects of relative humidity, wind velocity and hydrogen sulfide on the measured values were negligible. In a field survey, 65 workers in a viscose rayon factory wore both the diffusive sampling tube and a commercially available 3M 3500 organic vapor monitor on their collar during their 8-hr work period. CS2 concentrations obtained by the two methods were comparable and the correlation coefficient was 0.931. This method proved to be useful in determining the concentrations of CS2 to which workers were exposed.

Carbon Disulfide↗
PubMed1997

Induction of metallothionein-like cadmium-binding protein in the testis by oral cadmium administration in rats.

The possible induction of a metallothionein (MT)-like Cadmium (Cd) binding protein (MT-like Cd-BP) was investigated in rat testis after oral Cd administration. Male Wistar rats were given Cd by oral administration (20 mgCd/kg, for 10 weeks), while the experimental controls were given Cd by intraperitoneal (i.p.) injection (2 mgCd/kg). Cd concentration increased in the testes after both administrations. However, much more Cd (about 4 times) accumulated in the tests of rats receiving oral Cd administration than in rats receiving Cd ip injection (experimental control). Meanwhile, MT-like Cd-BP decreased dramatically in the testes after Cd i.p. injection compared to that in the testes of untreated control rats. However, this testicular MT-like Cd-BP after oral Cd administration increased significantly up to about 1.4 times of the amount found in the testes of untreated control rats. Inhibition of glutathione S-transferase (GST) activity and decreased glutathione (GSH) in the testes was not observed in rats after oral Cd administration. However, enzyme activity and GSH concentration were inhibited and decreased significantly in the testis by Cd toxicity after Cd i.p. injection. These results indicate that testicular MT-like Cd-BP, assumed to be MT and to be hardly inducible by Cd, is an inducible protein corresponding to increased Cd accumulation in the testis without damage by Cd toxicity after oral Cd administration.

Administration, Oral↗
PubMed1996

A 460-kb DNA sequence of the Escherichia coli K-12 genome corresponding to the 40.1-50.0 min region on the linkage map.

The 465,813 base pair sequence corresponding to the 40.1-50.0 min region on the genetic map of Escherichia coli K-12 (W3110) was determined. Analysis of the sequence revealed that this region contained at least 466 potential open reading frames, of which 187 (40%) were previously reported, 105 (23%) were homologous to other known genes, 103 (22%) were identical or similar to hypothetical genes registered in databases, and the remaining 71 (15%) did not show a significant similarity to any other gene. At the 45.2-46.0 min region, we found a very large cluster of about 30 genes, whose functions are involved in the biosynthesis of polysaccharides as the components of outer membranes. In addition, we identified a new asn-tRNA gene, designated asnW, between the asnT and asnU genes and a new lysogenic phage attachment site as the cis-element.

Attachment Sites, Microbiological↗
PubMed1996

Adenomatoid serous hyperplasia of sublingual gland: a case report.

We present an example of adenomatoid serous lobular hyperplasia of the sublingual gland. Pathologic examination revealed the lesion was composed of multiple aggregates of normal-appearing serous and mucous acini that varied in size. The ratio of serous gland to mucous glands was 7 to 1. We cannot identify the cause of this condition, however, calcium channel blocking agents prescribed for the treatment of this patient's essential hypertension cannot be ruled out as a pathogenetic factor in the development of the lesion.

Adenomatoid Tumor↗
PubMed1996

Early and late postoperative hearing preservation in patients with acoustic neuromas.

OBJECTIVE: To examine the incidence of postoperative hearing preservation and the factors that influence early and late postoperative hearing in patients with acoustic neuromas. METHODS: We reviewed the results of surgery and follow-up in 73 consecutive patients. RESULTS: Of 73 patients, 51 demonstrated preoperative hearing levels equal to or better than Class 3, according to the classification system of Gardner and Robertson (8). After surgery, 21 (41.2%) of the 51 patients retained Class 1, 2, or 3 hearing. Hearing was more likely to be preserved after surgery if the tumor was small and if the preoperative hearing was good. The early postoperative hearing grade declined in 7 (33.3%) of the 21 patients, compared with the preoperative hearing level. The long-term follow-up of 17 patients in whom measurable hearing was retained after surgery indicated that 3 (17.6%) experienced delayed worsening of hearing, without evidence of tumor recurrence. The extent of hearing loss in patients with successful hearing preservation was not correlated with tumor size, preoperative hearing, patient age, or the shape of the cochlear nerve on the tumor surface. Hearing at long-term follow-up was significantly better in patients with excellent preoperative hearing. CONCLUSION: Postoperative long-term preservation of hearing is more likely if surgery is performed while the tumor is still small and hearing is still excellent. Under these circumstances, it is more likely that the early and late hearing loss will be compensated.

Adult↗
PubMed1996

Breakthrough times for vapors of organic solvents with low boiling points in steady-state and pulsating flows on respirator cartridges.

The breakthrough times of five organic solvents at various vapor concentrations were measured in steady-state and pulsating flows on commercially available respirator cartridges. The relationship between the logarithmic vapor concentration and the logarithmic breakthrough time of each organic solvent showed an inverse correlation in both of the flow patterns. The organic solvents with lower boiling points exhibited the shorter breakthrough times in both of the flow patterns. The ratios of the breakthrough times in the pulsating flow to those in the steady-state flow were lower than 0.9 when the vapor concentrations were higher than 600 ppm for ethyl acetate, methyl acetate, acetone and dichloromethane. From the present study, the breakthrough in the pulsating flow tends to occur earlier than in the steady-state flow when using a highly concentrated vapor of an organic solvent with a low boiling point.

Equipment Safety↗
PubMed1996

Breakthrough time of a respirator cartridge for carbon tetrachloride vapor flow of workers' respiratory patterns.

Breakthrough times of a commercially-available respirator cartridge packed with a small amount of activated carbon were determined by three different flow patterns: workers' respiratory patterns, conventional steady-state flows, and three standard patterns consisting of rectangle, sine, and triangle waves. A mechanical breathing simulator was used to reproduce the three standard wave patterns as well as the workers' respiratory patterns, which had been recorded from three workers of a paint manufacturing plant wearing a gas mask equipped with a respirator cartridge. The breakthrough test was carried out with 300 ppm carbon tetrachloride vapor at average flow rates of the respiratory and standard patterns equivalent to the steady-state flow rates. The breakthrough times determined by the workers' respiratory patterns were found to be shorter than those by a steady-state flow of the equivalent flow rate, and to be as short as those by sine and triangle wave patterns. It was considered that shorter breakthrough times in the workers' respiratory patterns could be attributed to a faster maximum inspiratory flow rate than that in the case of steady-state flow. The present results suggest that the passing time of CCl4 molecules through the thin activated carbon layer of respirator cartridge may be too short to attain an adsorption equilibrium.

Adolescent↗
PubMed1996

Induction of DNA breaks in cardiac myoblast cells by norepinephrine.

We measured DNA single strand breaks (SSB) in cardiac myoblast cells in response to norepinephrine (NE) stimulation. Rat cardiac myoblast cells (H9c2) were stimulated with concentrations of 100 microMs to 1 mM NE for 2, 3, 4, and 12 hours after prior incubation with control solution, bunazosin, propranolol, verapamil, or captopril for 30 min. The DNA damage was measured by fluorometric alkaline elution. The strand scission factor, an index of the severity of SSB, increased slightly after stimulation with 200 microMs NE for 12 hours and with 1 mM NE for 4 hours. This increase was prevented by catalase or superoxide dismutase, which prevent production or accumulation of active oxygen radicals, during the stimulation, but not by pretreatment with a alpha-receptor antagonist, a beta-adrenergic receptor antagonist, a Ca2+ antagonist, or an angiotensin converting enzyme inhibitor. Thus, DNA SSB were induced by NE in cardiac myoblast cells. Certain active oxygen species may contribute to the DNA damage induced by NE.

Adrenergic alpha-Agonists↗
PubMed1996

Coxsackievirus B3 genomes detected by polymerase chain reaction: evidence of latent persistency in the myocardium in experimental murine myocarditis.

We have investigated the time course after infection in coxsackievirus B3 murine myocarditis to determine the extent (if any) of persistent or latent infection that might be responsible for recurrence. We employed a polymerase chain reaction (PCR) method that can detect an extremely small amount of genome by amplification techniques in four-week-old BALD/c mice (n = 140) infected with coxsackievirus B3 by a single intraperitoneal injection of 1 x 10(4) plaque-forming units (PFU)/mouse (Group 1) and 1 x 10(2) PFU/mouse (Group 2). Mice were sacrificed on days 3, 5, 7, 10, 14, 21 and 28, and their hearts were resected for RNA extraction. Single chain DNA was synthesized from 1 microgram of RNA and the viral genome was amplified by PCR. The virus genome was strongly amplified in Group 1 from days 3 to 10, and in Group 2 from days 5 to 7, but afterwards both amplifications rapidly diminished. However, a positive signal, though very faint, persisted in both groups until day 28, by which time all histological evidence of myocarditis had disappeared in Group 2. Our results demonstrated that there was persistent or latent virus infection in the myocardium throughout the entire study period of 28 days. Such persistence might provide a pathomechanism for the exacerbation and recurrence of myocarditis.

Animals↗