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Biomedical subjects

T Yamashiro

Publications and source records attributed to T Yamashiro.

At least 91 records · Page 5Linked to original sources
PubMed1993

Pili of vibrio cholerae widely distributed in serogroup O1 strains.

The distribution of Vibrio cholerae O1 pili consisting of 16 kDa subunit protein (16K-pili) was examined by Western blotting, using 211 strains from various origins and specific anti-16K-pili sera. The 16 kDa protein was detected in all 211 strains. The pili were purified from 3 El Tor and 3 classical strains, and characterized by hemagglutination and inhibition tests. All purified pili were hemagglutinative. However, the hemagglutinating activity of classical pili disappeared after exposure to 5 M urea and the agglutination induced by the classical pili was inhibited by D-mannose, alpha-methylmannoside, D-glucose and N-acetylglucosamine. On the contrary, El Tor pili were resistant to these sugars and urea.

Amino Acid Sequence↗
PubMed1993

Purification and characterization of pili of a Vibrio cholerae non-O1 strain.

Pili of the Vibrio cholerae non-O1 strain V10 were purified and characterized. The V10 pili were physicochemically and immunologically different from those of the previously reported V. cholerae non-O1 strain S7, although the pili of the two strains had homologous N-terminal amino acid sequences. V10 plus antigen was detected only in V. cholerae non-O1 strains.

Amino Acid Sequence↗
PubMed1993

[Anesthetic management of a patient with HELLP syndrome with bronchial asthma].

We gave anesthesia for cesarean section to 30 year-old female with HELLP syndrome with bronchial asthma. HELLP syndrome is characterized by hemolysis, liver dysfunction and thrombocytopenia, besides syndrome of severe toxemia of pregnancy. After intubation with sevoflurane, diazepam and vecuronium, anesthesia was maintained with nitrous oxide, oxygen, sevoflurane and vecuronium, because she had an attack of bronchial asthma before operation. Though she had no eclampsia nor hypertension during operation, her babies were intubated and were cared in pediatric ward. Though she had improvements of liver dysfunction and thrombocytopenia after operation, it took 2 days to extubated, because she had frequent attacks of bronchial asthma. We conclude that we should perform cesarean section for a patient with HELLP syndrome as soon as possible.

Adult↗
PubMed1993

[A basic study on bradycardiac dysrhythmias following atrial surgery].

Various dysrhythmias often developing atrial surgery can be lethal, although the precise mechanism remains unknown. An experimental study was conducted to elucidate the influence of internodal tract injury and sinoatrial node (SAN) artery blockade on bradycardiac arrhythmias, using 40 adult mongrel dogs. Changes in rhythm, SAN tissue flow rate, SAN function and His bundle electrocardiogram were evaluated in those with complete division of the internodal tract (INT) and/or artery blockade under cardiopulmonary bypass. The results were as follows: 1) Junctional rhythm (JR) or ectopic atrial rhythm (ER) occurred in 87.5% of those subjected to anterior INT (AINT) division+SAN artery blockade, whereas such arrhythmias developed in none of those with division of any single INT alone, and appeared in only 18% of those with SAN artery blockade alone; 2) The SAN tissue flow rate was reduced to 29 +/- 17% of the control level by AINT division+SAN artery blockade, while it was reduced to only 91 +/- 16%, 84 +/- 12% and 90 +/- 18% by division of AINT, MINT and PINT, respectively, and 55 +/- 16% by SAN artery blockade (The former was significantly lower than the latter two (p < 0.01)); 3) None of those with the SAN tissue flow rate of less than 10 Laser Doppler Flowmeter unit (LDF unit) by laser Doppler flowmeter output were capable of maintaining sinus rhythm (SR) with its minimum requirement that was assumed to be more than 10 LDF unit; 4) Immediately before shifting to JR, corrected sinus recovery time (CSRT) was elongated, indicating a hypofunction of the SAN; 5) The A-H interval was more significantly prolonged by AINT division than by either of the other two divisions (p < 0.01). Division of the AINT brought about prolongation of the A-H interval, and AINT division+SAN artery blockade caused a marked SAN hypofunction. It was inferred that preservation of both the AINT and the SAN artery should be of vital importance in preventing surgical bradycardiac arrhythmias.

Animals↗
PubMed1992

Electrophysiologic study of dysrhythmias after atrial operations in dogs.

Experiments were conducted with 159 dogs to investigate the mechanism of persistent dysrhythmias clinically encountered after atrial-level operations. Those found after incisions to the internodal pathways (INPs) of the right atrium were analyzed using cardiac mapping in an anesthetized or extracorporeally perfused state. Longitudinal incisions of the posterior INP often allowed inducible sustained atrial flutter, with circus movement of excitation around the right atrium near the tricuspid orfice. Sustained atrial flutter thus produced was modified in cycle length by coexisting division of the middle INP but inhibited by that of the anterior INP. Its incidence increased at chronic stage, with marked cicatricial changes. The disrupted anterior INP markedly prolonged conduction time to the atrioventricular node and A-H interval compared with the other disruptions. Persistent atrioventricular junctional rhythm developed in about 50% of the animals after disruption of all three INPs or anterior and posterior INPs; division of the anterior INP was the common potent factor, although no single blocked INP produced persistent junctional rhythm. Our results support the "summation theory." The incidence of junctional rhythm and hypoxia of the sinoatrial node (flow rate of less than 10 mL.100 g-1.min-1) were markedly enhanced by coexisting blockade of atrial feeding arteries in addition to division of the anterior INP. In conclusion, massive posterior INP disruption is a potent anatomic substrate in producing sustained atrial flutter, middle INP division a modifier, and anterior INP division an inhibitor. Division of the anterior INP is a potent anatomic substrate in producing junctional rhythm, and hypoxia involving the sinoatrial node reacts as its synergic factor.

Animals↗
PubMed1992

The effect of local application of 1,25-dihydroxycholecalciferol on osteoclast numbers in orthodontically treated rats.

Orthodontic tooth movement requires remodeling of periodontal tissues, especially alveolar bone. 1,25-(OH)2D3, the active form of vitamin D3, is known to be a potent stimulator of osteoclastic bone resorption. The purpose of this study was to investigate the effect of local application of 1,25-(OH)2D3 on osteoclast numbers induced by experimental tooth movement. A piece of orthodontic elastic band was inserted between the first and second upper molars of male Wistar rats weighing about 200 g each. Twenty microL of 1,25-(OH)2D3 (10(-12)-10(-7) mol/L) was injected locally into the submucosal palatal area of the root bifurcation of the right first molar. The left side was injected with phosphate-buffered saline (PBS). The number of osteoclasts was counted in a 700 x 1050 microns 2 area of the interradicular septum. The local injection of 1,25-(OH)2D3 caused a dose-dependent increase in osteoclast number. The effect of 1,25-(OH)2D3 reached a response plateau at 10(-10) mol/L when greater than a three-fold rise in osteoclast number was attained compared with the PBS-treated controls. While the insertion of a piece of elastic band for three days induced a significant increase in osteoclasts in the alveolar bone, daily injections of 20 microL of 10(-10) mol/M 1,25-(OH)2D3 for three days markedly stimulated the numbers of osteoclasts induced by the insertion of an elastic band. 1,25-(OH)2D3 was apparently synergistic with mechanical stimuli, resulting in enhancement of the numbers of osteoclasts induced by mechanical stimuli alone.(ABSTRACT TRUNCATED AT 250 WORDS)

Alveolar Process↗
PubMed1992

Effect of age on the rate of tooth movement in combination with local use of 1,25(OH)2D3 and mechanical force in the rat.

The purpose of this study was to compare the amount and rate of tooth movement in young and mature rats administered 1,25(OH)2D3 simultaneous with application of mechanical force. In 30 seven-week-old and 30 28-week-old male Wistar rats, the right maxillary first molar was moved buccally with a fixed appliance. The appliances delivered forces ranging from 5 to 20 g. Twenty microL of 1,25(OH)2D3 (10(-10) and 10(-8) mol/L) was injected locally into the submucosal palatal area of the root bifurcation of the right first molar. The left side was injected with phosphate-buffered saline (PBS). In young rats receiving 10(-10) mol/L 1,25(OH)2D3 every three days, tooth movement significantly increased to 126% of that in PBS-injected control rats on day 20. In 1,25(OH)2D3-injected mature rats, tooth movement was stimulated markedly and increased with 10(-10) mol/L to 245% and with 10(-8) mol/L to 154% of the amount of tooth movement seen in the PBS-injected controls by the end of the experiment. PBS-injected rats had a plateau stage where tooth movement did not occur at all, while there was no such lag-time in the 1,25(OH)2D3-injected group which showed continuous tooth movement. The local injection of 1,25(OH)2D3 did not change serum calcium, phosphate, and alkaline phosphatase activity, and there were no apparent clinical or microscopic side-effects.

Activator Appliances↗
PubMed1992

Differential effects of 1 alpha, 25-dihydroxycholecalciferol and 24R,25-dihydroxycholecalciferol on the proliferation and the differentiated phenotype of rabbit craniofacial chondrocytes in primary culture.

The response of chondrocytes from the craniofacial complex to vitamin D3 has been investigated in vitro. Chondrocytes were isolated from nasal septal cartilage (NSC), sphenooccipital synchondrosis (SOS) and mandibular condylar cartilage (MCC) of New Zealand rabbits weighing from 250-350 g. Treatment of NSC-chondrocytes with 1,25-(OH)2D3 or 24,25-(OH)2D3 for 6 days from days 4 to 10 in medium containing charcoal-treated FBS increased DNA synthesis dose-dependently at the concentrations of 10(-9) M to 10(-8) M, or 10(-11) M to 10(-9) M, respectively. 1,25-(OH)2D3 inhibited GAG synthesis dose dependently at the concentrations of 10(-11) M to 10(-8) M. 24,25-(OH)2D3 had no effect on GAG synthesis in NSC-chondrocytes. 1,25-(OH)2D3 increased DNA synthesis in SOS-chondrocytes at a concentration of 10(-10) M and inhibited GAG synthesis. 24,25-(OH)2D3 had no significant effect on DNA and GAG syntheses of SOS-chondrocytes. 1,25-(OH)2D3 slightly increased GAG synthesis at a concentration of 10(-10) M in MCC-chondrocytes but had no effect on DNA synthesis. 24,25-(OH)2D3 had no effect on DNA and GAG synthesis in MCC-chondrocytes at concentrations of 10(-11) M to 10(-9) M. These finding suggest that vitamin D3 metabolites, 1,25-(OH)2D3 and 24,25-(OH)2D3 play an important role in the growth of craniofacial cartilage by differently stimulating proliferation and expression of the differentiated phenotype of chondrocytes from NSC, SOS and MCC.

24,25-Dihydroxyvitamin D 3↗
PubMed1991

[Studies on clinical significance of "Streptococcus milleri group" in respiratory infections].

"Streptococcus milleri group" are the part of the indigenous oral flora, and they are proposed to contain three distinct species: Streptococcus anginosus, Streptococcus constellatus, and Streptococcus intermedius. Though not included in the approved lists of bacterial names, "S. milleri group" are regarded as the causative organisms of suppurative infections, such as oral abscess, brain abscess, lung abscess and empyema. I have studied the clinical significance of the "S. milleri group" in respiratory infections. An investigation was performed to confirm the incidence of "S. milleri group" colonization in healthy 120 volunteers' (20 y/o-80 y/o) throats, and it was found that 11.7% (14/120) were positive. On the other hand, attention should be paid to the fact that the "S. milleri group" was highly isolated, 24 (24.7%) in 97 purulent respiratory specimens (94 sputa and 3 throat swabs) from which no other significant microorganism was recovered. I have measured the serum antibody titers of the "S. milleri group", employing the IFA technique, in 10 patients from whose specimens "S. milleri group" was predominantly isolated, and compared with those of 18 healthy volunteers. Whereas all of the titers of healthy volunteers reveal less than 1:256, those of the patients reveal more than 1:512. And antibody titers to "S. milleri group" showed the highest in two weeks after "S. milleri group" isolation, and came down to healthy adult levels in six weeks or more. Thus far, about half of the causative organisms of acute pneumonia have been reported unknown. In this study I have suggested that the "S. milleri group" plays an important role as the causative organism in respiratory infections including pneumonia.

Adult↗
PubMed1990

[Methicillin-resistant Staphylococcus aureus (MRSA) infection--significance of MRSA in respiratory tract infection].

We have examined background factors in MRSA infection in cases in which S. aureus had been isolated from sputa. The incidence of isolation of S. aureus was high and still increasing in expectorated sputa, and causative organisms in the cases of pneumonia and autopsied lungs. A significant correlation was observed between high incidence of isolation of S. aureus and abuse of third-generation cephems. MRSA isolation rates of inpatients was higher than that of outpatients. Among the inpatients such cases with severe underlying diseases and prolonged admission showed the highest incidence of isolation of MRSA. There seemed to be a correlation between distribution of patients with S. aureus and that of rooms with S. aureus in the air. This suggests nosocomial infection. Although MRSA was frequently isolated from sputa, most cases showed no signs of infection, and this suggested that they had been transient colonization. Such antimicrobial agents as rifampicin, teicoplanin, vancomycin reveal excellent antibacterial activity against MRSA and minocycline, ofloxacin were moderately effective. The physician must be informed of the significance of MRSA, because their understanding of MRSA still remains insufficient.

Anti-Bacterial Agents↗
PubMed1990

[A study of valve replacement in the elderly].

From March 1982 to June 1989, 42 valve replacements were performed in 41 consecutive elderly patients (age 60 years and older, mean age 76.0 years). Main etiology of their diseases is calcific AS 7 (4: bicuspid valve), degenerative AR 4, rheumatic AS/AR 5, AAE 2, MR due to MVP or chordal rupture 13, rheumatic MS/MR 13. Operative methods are AVR 14, MVR 22, DVR 6. Cumulative follow-up was 99.2 patient-years (mean 30.5 months). Operative deaths were 2 cases (4.8%) due to left ventricular ruptures after MVR. There were 4 late deaths (9.5%). Actuarial survival rate at 7 years was an overall of 70 +/- 12%. Most common early postoperative complication was AV conduction disturbances. Continuous III degrees AV Block 1, transient III degrees AVB 3 and transient II degrees AVB 1 occurred in 7 calcified AS cases with calcific deposition to the attachment of anterior half of the noncoronary cusp. Valve related late complications were thromboembolism (7%/patient-year) and prosthetic valve endocarditis (3%/patient-year). Actuarial incidence of event free survival among hospital survivors at 7 years was 55 +/- 11%. It is our belief that surgical treatment for elders should be rather positively done when medical therapy has not met desired effects, under well evaluation of senile weakness for each case.

Age Factors↗
PubMed1989

[Clinical study of the vulvar Paget's disease: report of 8 cases].

Between 1949 and 1987, 8 cases of the vulvar Paget's disease were treated at the Cancer Institute Hospital. These cases constituted 9.5% of the total number of the vulvar malignancies at our hospital during the same period. The clinicopathological findings were described. The average age was 73.3 years. The most frequent symptom was vulvar eczematous change with itching, which was seen in 7 cases (87.5%). About 5 years was required from onset of the disease until diagnosis. Vulvar cytologic examination revealed positive for cancer in 5 out of 8 cases (62.5%). One patient developed squamous cell carcinoma of the face. All patients underwent operation. Two patients had preoperative adjuvant chemotherapy by Bleomycin which was not effective histologically. Five patients had a underlying invasive tumor (62.5%) at initial therapy. The 5-year survival rate was 50.0%. Prognosis of the vulvar Paget's disease appears to be poor.

Aged↗
PubMed1989

[A case report of giant cell granuloma of the jaw].

A giant cell granuloma of the mandible seen in a 16 month-old boy was reported. Histopathology showed that the lesion consisted basically of granulation tissue with multinucleated giant cells, spindle-shaped and polygonal stromal cells. No atypia was seen in giant cells or stromal cells. Electron microscopic examination revealed that multinucleated giant cells possessed microvillous structure on their cytoplasm and were rich in organelles such as endoplasmic reticulum, mitochondria and dense bodies. Stromal cells consisted of macrophage-like and fibroblastic cells. Immunohistochemical examination demonstrated a large number of giant cells and stromal cells that were strongly positive for the antibodies of alpha-1-antitrypsin and alpha-1-antichymotrypsin. These morphological findings suggest that macrophage-like stromal cells are the precursors to giant cells.

Giant Cells↗
PubMed1989

[Comparison of ultrasound and computed tomography (CT) for the diagnosis of paraaortic lymphnode metastasis in patients with gynecologic malignancies].

Fifty-one patients with gynecologic malignancies were tested for paraaortic lymphnode metastasis by ultrasound and computed tomography (CT). Eleven patients were found to have paraaortic lymphnode metastasis by ultrasound, and CT also showed the same metastatic image in the same patients. The site and size of the positive image found by both means were identical. The other forty patients diagnosed by ultrasound as free of metastasis were also proved to have no metastasis by CT. Ultrasound is as useful as CT in the evaluation of paraaortic nodes. However, ultrasound is more convenient and easier to use than CT.

Adenocarcinoma↗
PubMed1989

[Clinical study of 84 primary vulvar carcinomas].

Between 1949 and 1987, 84 cases of primary vulvar malignancy were treated at the Cancer Institute Hospital. These cases accounted for 0.8% of the total number of gynecologic malignancies at our hospital during the same period. The clinicopathological findings were described. The mean age of the 84 cases was 61.7 years. The most frequent symptom was a vulvar mass, seen in 35 cases (41.7%). In preoperative cytologic examination of vulvar smears, 44/78 cases (56.4%) had suspected malignancy. Histopathologically, 57 cases (67.9%) were found to be squamous cell carcinoma. According to FIG0 staging system, there were 4 (4.8%) stage 0 tumors, 11 (13.0%) stage I tumors, 25 (29.8%) stage II tumors, 41 (48.8%) stage III tumors, and 3 (3.6%) stage IV tumors. The patients were treated by operation and/or irradiation. The five-year survival rate was 51.4% (36/70) in all stages. The five-year survival rate was 66.7% (2/3) in stage 0 cases, 87.5% (7/8) in stage I, 78.9% (15/19) in stage II, 28.9% (11/38) in stage III, and 50.0% (1/2) in stage IV, respectively. In patients treated by radical vulvectomy, the five-year survival rate was 26.7% (4/15) when there was inguinal nodal metastasis, and 73.7% (14/19) when there was no inguinal nodal metastasis. The five-year survival rate was 59.5% (25/42) in cases treated by operation and was 39.3% (11/28) in cases treated by irradiation. In preoperative adjuvant chemotherapy, the histopathological effect was 44.4% (4/9). In conclusion, the first choice for treatment of vulvar malignancy was considered the operative method.

Carcinoma, Squamous Cell↗
PubMed1989

[The usefulness of immunologic methods for diagnosis and follow-up study of a case of pulmonary dirofilariasis].

Nearly 70 cases of dirofilariasis have been reported in Japan. A case operated for pulmonary dirofilariasis is reported, together with useful immunologic diagnostic and follow-up study. A 62-year-old woman was admitted to our hospital with complaints of cough and right chest pain. A chest X-ray film revealed a mass approximately 4 cm in diameter in the right S9 region. Histological examination of the mass by TBLB revealed necrotic tissue containing eosinophils and Charcot-Leyden crystals. Around the area of necrosis there was granuloma with infiltrating neutrophils, eosinophils and lymphocytes. Therefore, immunologic examinations were performed on the suspicion of a parasitic disease. Ouchterlony's test was done with positive reaction against Dirofilaria immitis antigen. Results of the ELISA indicated a high antibody titer (1:12800) to Dirofilaria immitis antigen. Histological examination of a surgically removed mass gave the final pathologic diagnosis of pulmonary dirofilariasis caused by Dirofilaria immitis. A follow-up study by ELISA revealed a remarkable decrease of the antibody titer to 1:3200 at 1 month after surgery, to 1:200 at 6 months and to negative after 9 months. These results suggest that the ELISA could be used to judge the healing of the disease by drug therapy. Thus immunologic studies by Ouchterlony's test and the ELISA were considered to be useful for the diagnosis and follow-up study of dirofilariasis.

Animals↗
PubMed1989

[Surgical landmarks of course of atrioventricular conduction system].

There is a certain tendency in the relationship between the distribution of the conduction system and the type of VSD as classified by Soto and coworkers. The course of the conduction system and its surgical landmarks were investigated histologically in various cardiac anomalies. In perimembranous inlet VSD, the His bundle ran superficially on the crest of the ventricular septum. It ran on the left ventricular aspect and somewhat deeply in trabecular VSD and far deeply in infundibular VSD. In perimembranous inlet or trabecular VSD, the RBB laid beneath or just anterior to a series of upper-uppermost accessory papillary muscle when these were present and descended posteroinferior to the MPM, basically as in the normal heart. The upper-uppermost AcPM are reliable landmarks for the RBB. The RBB descended just anterior to the so called MPM (embryologically the uppermost AcPM--Van Mierop) in infundibular VSD and TOF. These findings have provided us useful bases for suture placement to avoid conduction disturbance.

Bundle of His↗