Biomedical subjects

H Kanazawa

Publications and source records attributed to H Kanazawa.

At least 127 records · Page 7Linked to original sources

PubMed1996

Mycotic aneurysm of the internal iliac artery caused by Klebsiella pneumoniae.

Mycotic aneurysms are rarely caused by Klebsiella species. We describe a male patient with diabetes mellitus and alcoholism who developed a mycotic aneurysm of the right internal iliac artery complicated by the formation of a false aneurysm. Klebsiella pneumoniae was cultured from arterial blood. An extra-anatomic bypass (left external iliac artery to right common femoral artery) was performed with a successful excision of the aneurysm.

Aneurysm, Infected↗

PubMed1996

[Multiple bronchial varices].

A 54-year-old man was referred to our hospital because of hemoptysis. Fiberoptic bronchoscopy revealed irregular mucosa of the right B1, B2, B3, B8, B9, and B10, and the left B1+2 and B3. Bronchoscopic and histological findings indicated bronchial varices.

Bronchi↗

PubMed1996

[Small-cell lung cancer and subacute sensory neuropathy in a patient positive for the anti-Hu antigen].

We encountered a case of small-cell lung cancer in a patient with subacute sensory neuropathy that began 5 months before the cancer was diagnosed. A 60-year-old man complained of abnormalities in the functioning of his peripheral sensory systems (senses of pain, touch, position, and vibration). A chest X-ray film obtained on admission showed an anterior mediastinal tumor. The anti-Hu antibody was found in his serum. The diagnosis was small-cell lung cancer. Combination chemotherapy (cisplatin and irinotecan, CPT-11) was begun and the response was a complete remission. The symptoms of neuropathy continued. The anti-Hu antibody was useful in the diagnosis in the case of small-cell lung cancer combined with subacute sensory neuropathy.

Acute Disease↗

PubMed1996

[Applicability of the dual interval echo train (DIET) method for female pelvic diseases].

Dual interval echo train fast SE (DIET-FSE) is a modified fast SE technique. It attenuates fat signals by applying a time interval between an excitation pulse and the first echo, which is the odd-number of the following echo interval, and by decreasing the number of high frequency refocusing pulses before collecting echoes in the center of the k space, which determines the contrast. Unlike many other fat-suppression methods, this technique is less affected by susceptibility effects. In this study, we compared DIET-FSE with FSE and conventional SE of the female pelvis. The results of DIET-FSE showed a stable, obvious fat suppression effect which resulted in the easy detection of pelvic organs such as the intestines and ovaries, as compared with FSE. The reductions in imaging time and motion artifacts also permitted more precise differentiation between the normal pelvic organs and lesions than conventional T2-weighted SE. These results imply that the DIET-FSE is useful for the diagnosis of female pelvic disorders.

Female↗

PubMed1996

Relationship between oral breathing and nasal obstruction in patients with obstructive sleep apnea.

In 30 normal subjects and 20 patients complaining of snoring or sleep apnea nasal percentage of total respiratory air volume (nasal fraction) was measured when nasal resistance was gradually increased. The switching point from nasal to oral breathing was also examined. Nasal respiratory resistance was measured by a rhinograph, and nasal fraction was measured with an inductive body-plethysmograph and with a CPAP nasal mask when the patients were at rest. Several sizes of cotton pledgets were inserted into the nasal vestibules as obturators, and nasal respiratory resistance and nasal fraction were measured repeatedly until subjects had to breathe through the mouth completely. Although the value of nasal respiratory resistance in patients with complaints of snoring or sleep apnea was higher than that of normal subjects, most of the patients did not complain of a sensation of nasal obstruction. However, the switching point from nasal to oro-nasal breathing in patients with complaints of snoring or sleep apnea was statistically higher than that in normal subjects. These results suggest that patients with complaints of snoring or sleep apnea can easily breathe through the mouth during sleep, and that chronic nasal obstruction may induce obstructive sleep apnea. Therefore, measurements of nasal respiratory resistance and nasal fraction are useful to evaluate obstructive sleep apnea.

Humans↗

PubMed1996

Changes in nasal and oral respiratory resistance before and after uvulopalatopharyngoplasty.

Twelve patients with complaints of sleep apnea were examined with the all-night sleep test. They underwent uvulopalatopharyngoplasty (UPPP) and were studied with the all-night sleep test again 3 to 6 months after the operation. Nasal and oral respiratory resistance was measured in sitting and supine position before and after surgery using a microrhinograph. The physiological effect of UPPP was also compared with the results of an MRI anatomical study. Nasal and oral respiratory resistance was significantly decreased post-operatively (p <0.05). The decreased value of post-operative nasal respiratory resistance in a supine position was more marked than that of oral resistance, suggesting that UPPP eliminates the obstruction at the soft palate, especially in a supine position. Although our study was performed in awake patients enlargement of the airway in the middle pharyngeal region may improve the nasal and oral respiratory function during sleep.

Airway Obstruction↗

PubMed1995

Adrenomedullin inhibits the secretion of cytokine-induced neutrophil chemoattractant, a member of the interleukin-8 family, from rat alveolar macrophages.

This study was undertaken to determine the effects of adrenomedullin (AM) on the secretion of cytokine-induced neutrophil chemoattractant (CINC), a member of the interleukin-8 family, from lipopolysaccharide-stimulated rat alveolar macrophages in vitro. AM significantly increased cAMP levels in alveolar macrophages in a dose-dependent fashion. On the other hand, AM significantly inhibited CINC secretion from alveolar macrophages in a dose-dependent fashion, and 8-bromo-cyclic adenosine monophosphate (8-Br-cAMP) also significantly inhibited CINC secretion. These findings suggest that AM may play important roles in the regulation of airway inflammation via a cAMP-dependent mechanism.

8-Bromo Cyclic Adenosine Monophosphate↗

PubMed1995

Essential aspartic acid residues, Asp-133, Asp-163 and Asp-164, in the transmembrane helices of a Na+/H+ antiporter (NhaA) from Escherichia coli.

The importance of negatively charged residues in transmembrane helices of many cation-coupled transporters has been widely demonstrated. Four Asp residues were located in the putative transmembrane helices of the Escherichia coli Na+/H+ antiporter, NhaA. We replaced each of these Asp residues by Asn in plasmid encoded nhaA and expressed these constructs in an E. coli mutant defective in both nhA and nhaB. Substitution of Asp-65 or Asp-282 (in the extramembrane region) had no effect on supporting the host mutant growth in the high NaCl- or LiCl-containing medium, and these two mutants had normal Na+/H+ and Li+/H+ antiporter activities. In contrast, substitution of Asp-133, Asp-163 or Asp-164 was detrimental to survival of the host mutant and impaired both Na+/H+ and Li+/H+ antiporter activities. These three Asp residues, conserved in the nhaA homologs from different species and which are located closely in the 3rd and 4th putative transmembrane helices, appear to play important roles in cation binding and transport.

Amino Acid Sequence↗

PubMed1995

Angiotensin II stimulates production of nitric oxide in guinea pig airways via AT1 receptor activation.

Angiotensin II (Ang II) and nitric oxide (NO) regulate a variety of physiological functions. In this study, we suggest that inhaled Ang II produces an initial bronchodilation apparently by stimulating NO production via AT1 receptors. Also, we demonstrate that following the initial bronchodilation, Ang II causes bronchoconstriction in the guinea pig, also via AT1 receptors. Both of the findings are important for our understanding of airway functions induced by Ang II.

Angiotensin II↗

PubMed1995

Enhancement of Escherichia coli H(+)-ATPase caused by binding of monoclonal antibodies is attributed to structural changes of Leu-456 and Ser-440 in the alpha subunit.

Five monoclonal antibodies against the alpha subunit of F1-ATPase from Escherichia coli alpha 104, alpha 105, alpha 107, alpha 109, and alpha 110 were prepared. The monoclonal antibodies alpha 104 and alpha 110 enhanced the F1-ATPase activity maximally to 1.6- and 1.7-fold that of the wild-type, respectively, while alpha 105 did not. Both antibodies bound to a peptide corresponding to the region between residues 354 and 513. Mutations in this region which caused reduced binding of the alpha subunit to the antibodies were identified at residues Ser-440, Leu-456, Leu-471, Leu-482, Met-483, and Ser-506 for alpha 104 and residues Ser-440, Leu-456, Leu-471, Asp-476, Leu-482, Met-483, and Ser-506 for alpha 110. These residues are possibly involved in the epitopes for the antibodies and are located close together on the surface of the alpha subunit. Among the mutations, Leu-456 to Pro and Ser-440 to Pro mutations caused increase of the F1-ATPase activity up to 1.9 and 1.2 times that of the wild-type, respectively, while Leu-471 to Pro mutation caused a defect in assembly of the F1-ATPase on the membrane. The other mutations caused no significant change in ATPase activity. These results suggested that Ser-440 and Leu-456 have an important role in regulating catalysis by the F1-ATPase, but that the neighboring residue Leu-471 has an important role in assembly of the F1-ATPase complex. It was also suggested that binding of the monoclonal antibodies alpha 104 and alpha 110 to residues Ser-440 and Leu-456 caused local conformational changes, leading to enhancing effects on F1-ATPase activity similar to the Ser-440 to Pro and Leu-456 to Pro mutations.

Animals↗

PubMed1995

Comparison of bronchodilator responses to adrenomedullin and proadrenomedullin N-terminal 20 peptide.

This study was designed to determine and compare airway responses to synthetic human adrenomedullin(AM) and proadrenomedullin N-terminal 20 peptide (PAMP) in anesthetized guinea pigs in vivo. 10(-7) M AM and PAMP significantly inhibited acetylcholine-and histamine-induced bronchoconstriction. However, this significant bronchodilator effect of PAMP lasted about five minutes, which was much shorter than that of AM. In addition, the bronchodilator effect of AM is approximately 100-fold more potent than PAMP. We demonstrated that PAMP had a potent bronchodilator activity, and induced a rapid and short-lasting bronchodilation. These findings suggest that AM and PAMP may play important roles in airway functions.

Acetylcholine↗

PubMed1995

Angiotensin II stimulates peptide leukotriene production by guinea pig airway via the AT1 receptor pathway.

Angiotensin II (Ang II) regulates a variety of physiological functions, including contraction of smooth muscle. Peptide leukotrienes (LTs) have recently been reported to be potent bronchoconstrictors and may play a role in the pathogenesis of airway inflammation. However, the possibility that Ang II and peptide LTs interact in the control of airway function has not been studied. In this study, we showed that Ang II receptors are present on guinea pig airway, and that they are of the AT1 subtype. We showed the possibility that Ang II induced the release of peptide LTs from guinea pig airway by activation of the AT1 receptor pathway. Our findings thus suggest that interaction between Ang II and peptide LTs might increase airway inflammation in the guinea pig.

Airway Resistance↗

PubMed1995

Inactivation of cholinesterase by ascorbic acid in the presence of cupric ions: a possible mechanism for the inactivation of an enzyme by the metal-catalyzed oxidation system.

The mechanism of inactivation of cholinesterase (EC 3.1.1.8) by the Cu2+ -ascorbic acid (AsA) system was investigated. Incubation of the enzyme with the Cu2+ -AsA system under aerobic conditions resulted in an irreversible loss of enzyme activity. At low concentrations of Cu2+, the extent of inactivation showed the same dependence in accordance with the extent of oxidation of AsA. Saturation kinetics were observed with respect to the concentration of AsA. No change in the dissociation constant of the enzyme-AsA complex was observed at various concentrations of Cu2+. Catalase at a low concentration partially protected the enzyme from the inactivation, but did not affect the oxidation of AsA. In addition, catalase at a high concentration completely protected both the enzyme from inactivation and the AsA from oxidation. Both thiourea and thiocyanate completely protected the enzyme from the inactivation, while AsA was partially oxidized only in the initial phase. Our proposed mechanism for the inactivation of an enzyme by the Cu2+ -AsA system is as follows. A ternary complex involving the enzyme, Cu2+ and AsA is formed. This is followed by a redox reaction within the complex which generates a superoxide (.O2-) and hydrogen peroxide (H2O2). The H2O2 then reacts with .O2- in a Haber-Weiss reaction producing the hydroxyl radical (.OH). Another role of H2O2 is the conversion of the reduced Cu+ within the complex to Cu2+. Thus, repeated cycles of the redox reaction between the Cu2+ and AsA take place at the same locus, producing multiple .OH, which causes its complete inactivation.

Animals↗

PubMed1995

Portal hypertensive colopathy: endoscopic findings and the relation to portal pressure.

Portal hypertensive colopathy (PHC) is a new clinical entity in patients with liver cirrhosis. In this study, colonoscopic findings and clinical features including upper gastrointestinal endoscopy and hepatic hemodynamics were prospectively investigated among 35 PH patients with a hepatic venous pressure gradient (HVPG) of greater than 12 mmHg due to chronic liver diseases. Colonoscopy was also performed in 100 patients without liver disease as non-PH controls. The colonoscopy revealed vascular ectasias, vascular irregularity, vascular dilatation, solitary red spots, diffuse red spots, and hemorrhoids in 26, 32, 30, 25, 10 and 25, respectively, of 35 PH patients compared to 3, 7, 3, 11, 0 and 19, respectively, in controls. PHC was endoscopically diagnosed in 27 of 35 PH patients according to our criteria. These patients with PHC were more frequently associated with esophageal varices and portal hypertensive gastropathy, and had higher HVPG than PH patients without PHC. Portal hypertension is an important factor in the etiology of PHC.

Adult↗

PubMed1995

Thrombomodulin in exercise-induced asthma.

Thrombomodulin (TM) is a membrane protein present in the vascular endothelium. It has also been found in human plasma, within which, however, its pathological functions have not been clearly described. In this study, the plasma TM concentrations in 19 asthmatic patients were determined by sandwich enzyme immunoassay using two monoclonal antibodies for human TM. The concentration of plasma TM in exercise-induced asthma (EIA)-positive asthmatic patients was significantly increased by exercise challenge. In addition, for these patients a positive correlation was found between the severity of EIA and the degree of change in plasma TM induced by exercise challenge. These findings suggest that the increase in influx of TM into the plasma in EIA-positive asthmatics may be due to generalized pulmonary endothelial damage following exercise challenge.

Adolescent↗

PubMed1995

[Transjugular intrahepatic portosystemic shunt for upper gastrointestinal bleeding due to portal hypertension: 2-year results].

We performed transjugular intrahepatic portosystemic shunt (TIPS) in 25 patients with liver cirrhosis who developed upper gastrointestinal bleeding due to portal hypertension. The procedure was successful in 23 patients, in whom portal pressure decreased by 51%. Bleeding was stopped in all 5 emergency for whom other treatments, including sclerotherapy, had failed. During the follow-up period (mean: 367 days), shunt dysfunction due to stenosis was observed in 75% of the patients. However, by percutaneous transluminal angioplasty, the patency could be maintained in 85% of the cases after 1 year and 73% of the cases after 2 years. Re-bleeding was observed in 13% of the cases after both 1 and 2 years. Color Doppler ultrasonography was useful for detecting shunt dysfunction. TIPS seems to be an effective treatment of upper gastrointestinal bleeding due to portal hypertension.

Adult↗

PubMed1995

[Syphilitic thoracic aortic aneurysm with destruction of vertebral body, producing numbness of lower extremities and paraplegia].

Numbness and paraplegia are uncommon complaints in patient with thoracic aortic aneurysm (TAA). The patient was a 64-year-old man. He suffered numbness and gait disturbance (paraplegia). The blood examination showed no positive findings except a Wassermann was positive. Roentgen examination of the chest showed two abnormal shadows like tumors. The CT and MRI revealed destruction of the vertebral bodies and TAAs adjacent to the spinal cord. After the graft replacement was performed, numbness and paraplegia disappeared. This suggests that in our patient the TAAs destruct the vertebral body and produce pressure on the spinal cord, causing numbness and paraplegia. We experienced a rare case of the syphilitic TAA producing bone destruction, numbness and paraplegia.

Aortic Aneurysm, Thoracic↗

PubMed1995

[Thoracoscopic treatment of a giant bulla: a case report].

A 38-year-old man was admitted to our hospital because of left giant bulla and pneumothorax. His chest X-rays and CT scan showed giant bulla of the left upper lobe and left pneumothorax. We performed bullectomy using the ENDOPATH ENDO LINEAR CUTTER 60 mm and 35 mm disporsable surgical stapler under thoracoscopic guidance. Clipping with end-clips and fibrin glue were effective for miner air leakage. There were no complications such as prolonged air leakage or incomplete lung re-expansion. His post operative couse was uneventful and he was discharged from the hospital on the 11th post operative day. When performed along with mini-thoracotomy, thoracoscopic operation is useful in treating patients with giant bulla.

Adult↗