Biomedical subjects

H Adachi

Publications and source records attributed to H Adachi.

At least 325 records · Page 18Linked to original sources

PubMed1993

[Replacement of ascending and transverse aorta using zero-porocity gelatin impregnated graft].

Gelatin impregnated Dacron graft was used without preclotting for the replacement of ascending and transverse aorta in 11 cases. The replacement of transverse aorta was performed in six patients with atherosclerotic aortic arch aneurysms and two patients with aortic dissections. The replacement of ascending aorta was performed in two patients with annlo-aortic ectasia and one patient with aortic dissection. Five of 11 patients (45%) needed emergency surgery due to the aortic rupture. Bleeding from the graft was not recognized clinically in all cases during the full heparinized cardiopulmonary bypass ranged from 153 min to 260 min. One patient (9%) with the rupture of transverse aorta died at the 7 th post operative day due to the multiple organ failure. No complication related to the graft was observed in all cases. Zero-porocity gelatin impregnated graft was useful for the replacement of aorta, especially for the replacement of ruptured ascending and transverse aorta in emergency situation.

Adult↗

PubMed1993

[A case report of the preoperative diagnosis of thoracoabdominal aortic aneurysm by three-dimensional CT angiography].

A sixty-year-old woman with the thoracoabdominal aortic aneurysm (7 cm in the diameter) was evaluated by the newly developed three-dimensional CT angiography. The thoracoabdominal aortic aneurysm was scanned by spiral CT and three-dimensional images were generated preoperatively. The three-dimensional structures of the thoracoabdominal aorta with the aneurysm, the celiac trunk and the superior mesenteric artery were clearly visualized by this method. The thoracoabdominal aorta was replaced by the graft with the reconstruction of celiac trunk. The post-operative course was uneventful. The preoperative diagnosis of thoracoabdominal aortic aneurysm by this method was very useful in the determination of operative procedure in this case. Three-dimensional CT angiography may be the useful method in the preoperative diagnosis of the aortic surgery.

Aorta, Abdominal↗

PubMed1993

[Selective cerebral perfusion with cold blood for the aortic arch surgery].

In seventeen patients with aortic arch aneurysms including seven emergency cases, the selective cerebral perfusion with cold blood (16 degrees C) was applied for the cerebral protection during the surgical procedure. Fifteen of them (88%) including the patient with the long cerebral perfusion (236 min) recovered perfectly and discharged. The selective cerebral perfusion with cold blood may be one of the safe and reliable methods for the repair of aortic arch aneurysm.

Adult↗

PubMed1993

[Cerebral protection with selective cold blood cerebral perfusion by gravity during aortic arch reconstruction].

Selective cold blood cerebral perfusion by gravity using specially designed reservoir with a built-in heat exchanger was applied to 30 consecutive patients who required aortic arch reconstruction. Rectal and brain temperature during cerebral perfusion were maintained at 22 degrees C and 16 degrees C respectively. Patients were divided into two groups according to postoperative condition of consciousness. Twenty three patients had uneventful recovery of consciousness (Group-1), and 7 patients showed delayed recovery or disturbance of consciousness (Group-2). Age, sex, causes of aneurysm, rectal temperature and conditions of cerebral perfusate were not statistically significant in both groups. Selective cerebral perfusion time in Group-1 was 68 +/- 36 min and 85 +/- 31 min in Group-2 (statistically not significant). Extracorporeal circulation time in Group-2 (243 +/- 61 min) was significantly longer than in Group-1 (187 +/- 56 min) (p < 0.05). Five of seven patients (71%) in Group-2 were in shock pre- or early post-operative period contrary to 0% in Group-1 (p < 0.001). These results suggest that selective cold blood cerebral perfusion protects effectively the brain during aortic arch reconstruction in the patients without hemodynamic deterioration.

Adult↗

PubMed1993

High-risk groups and screening strategies for early detection of hepatocellular carcinoma in patients with chronic liver disease.

Characteristics of high-risk groups for hepatocellular carcinoma (HCC) in Japan were studied to establish screening strategies for early detection of the tumor. Some 93% of patients with HCC were associated with chronic liver disease. On the other hand, 67% of patients with liver cirrhosis had HCC at autopsy. Most were related to current hepatitis virus infection. An analysis of risk factors among 120 patients with chronic hepatitis revealed that age and histological findings were independent risk factors, while HBsAg, anti-HCV, sex, history of heavy drinking, history of blood transfusion were not independent risk factors. Multivariate analysis of 239 patients with liver cirrhosis demonstrated that age, positivity for HBsAg and/or anti-HCV, family history of liver disease, hepatic reserve, and a history of radical resection were independent factors related to the development of HCC. A screening schedule for cirrhotic patients was established in accordance with these results; ultrasonography was done every three months, and tumor markers measured every two months. The screening strategy proved to be effective for the early detection of HCC and improvement of the prognosis.

Aged↗

PubMed1993

[Preoperative diagnosis of the thoracic aortic aneurysm by three-dimensional CT angiography].

Serial eight patients with thoracic aortic aneurysms were evaluated by a newly developed three-dimensional CT angiography (3D-CT) from December 1992 to January 1993. The patients include 3 aortic dissections, 3 aortic arch aneurysms, one descending aortic aneurysm and one thoracoabdominal aortic aneurysm. The surgical treatment was performed after the evaluation of 3D-CT, and the operative findings were compared to the three-dimensional images reconstructed by 3D-CT in all patients. Three-dimensional displays were achieved using the unique method of data collection of the helical (spiral) scanner with continuous tube rotation and continuous table feed. A intravenous contrast material was used to image the thoracic aorta and major aortic branches with the single-breath-hold technique. Two and three-dimensional images reconstructed by 3D-CT were displayed within 10-20 minutes after the scanning. These three-dimensional images of the aortic lesions could be displayed in any angle we chose. Three-dimensional structures of the thoracic aorta and major aortic branches were clearly visualized and easily recognized by 3D-CT. These images were similar to the intraoperative findings and were quite useful to determine the operative procedure. The successful repair of thoracic aortic aneurysm was achieved in all cases. 3D-CT is a new and attractive modality to assess the vascular system. Although our experience is limited, 3D-CT may be a useful and powerful diagnostic method for the surgical treatment of thoracic aortic aneurysm.

Adult↗

PubMed1993

[Surgical treatment of aberrant right subclavian artery aneurysm].

A 77-year-old female was admitted with dysphagia and back pain. Angiography revealed an aberrant origin of the right subclavian artery from the posterior aspect of the proximal descending thoracic aorta just distal to the origin of the left subclavian artery. The origin of the right subclavian artery was aneurysmal (maximum transverse diameter was 8 cm), and this aneurysm was causing compression of the esophagus. The patient was treated by Teflon patch graft aortoplasty and right subclavian artery reconstruction with the aid of cardiopulmonary bypass and hypothermic selective cerebral perfusion. Postoperative course was uneventful and there were no major complications.

Aged↗

PubMed1992

Molecular structure of the acyl-enzyme intermediate in beta-lactam hydrolysis at 1.7 A resolution.

The X-ray crystal structure of the molecular complex of penicillin G with a deacylation-defective mutant of the RTEM-1 beta-lactamase from Escherichia coli shows how these antibiotics are recognized and destroyed. Penicillin G is covalently bound to Ser 70 0 gamma as an acyl-enzyme intermediate. The deduced catalytic mechanism uses Ser 70 0 gamma as the attacking nucleophile during acylation. Lys 73 N zeta acts as a general base in abstracting a proton from Ser 70 and transferring it to the thiazolidine ring nitrogen atom via Ser 130 0 gamma. Deacylation is accomplished by nucleophilic attack on the penicilloyl carbonyl carbon by a water molecule assisted by the general base, Glu 166.

Acylation↗

PubMed1992

Primary structure of rat renal dipeptidase and expression of its mRNA in rat tissues and COS-1 cells.

Three cDNA clones of rat renal dipeptidase (rrDP) were isolated from rat renal and pulmonary cDNA libraries using a DNA fragment of human renal DP cDNA clone, MDP4, as a probe. The complete amino acid sequence deduced from the cDNA contains 410 amino acid residues, beginning with a signal peptide of 16 amino acid residues. RNA blot hybridization analysis showed that 1.6 and 2.2 kb mRNAs were expressed in lung and kidney, however, only 1.6 kb mRNA was detected in small intestine. COS-1 cells transfected with the cDNA expressed enzymatically active rrDP.

Amino Acid Sequence↗

PubMed1992

Polyclonal antibody against an inducible form of nitric oxide synthase purified from the liver of rats treated with Propionibacterium acnes and lipopolysaccharide.

A polyclonal antibody was raised in the rabbit against an inducible form of nitric oxide (NO) synthase (EC 1.14.23) purified from the liver of rats with acute liver necrosis induced by i.v. administration of Propionibacterium acnes and lipopolysaccharide. The antibody immunoprecipitated NO synthase activities in the soluble extract of the liver from treated rats. Western blot analysis showed that the cytosols of the liver, lung and spleen from the treated rats but not from non-treated rats, and that of murine macrophages cultured in the presence of lipopolysaccharide and interferon-gamma, contained immunoreactive protein with a molecular weight of 125 kDa. The antibody, however, does not cross-react with a 150 kDa constitutive form of NO synthase present in the brain of rats, indicating that the inducible and constitutive enzymes are immunologically distinguishable.

Amino Acid Oxidoreductases↗

PubMed1992

Induction of Ca2+/calmodulin-dependent NO synthase in various organs of rats by Propionibacterium acnes and lipopolysaccharide treatment.

Ca2+/calmodulin-dependent nitric oxide synthase was found to be induced during rat liver necrosis caused by administration of Propionibacterium acnes and E. coli lipopolysaccharide to rats. Examination of the specific induction of Ca2+/calmodulin-dependent NO synthase showed that the enzyme was induced in the lung, spleen and colon as well as the liver. Northern blot analysis revealed that the induction occurred at the transcriptional level.

Amino Acid Oxidoreductases↗

PubMed1992

CD4 and CD8 regulate interleukin 2 responses of T cells.

To characterize the T-cell surface molecules involved in regulation of T-cell interleukin 2 (IL-2) responses, we established several monoclonal antibodies (mAbs) that inhibit IL-2 responses of freshly isolated CD8+ T cells and the IL-2-dependent cell line CTLL-2. Here we show that two inhibitory mAbs are directed against Lyt-2 (CD8 alpha). In fact, all anti-Lyt-2 mAbs tested were able to inhibit the IL-2 response of the Lyt-2- and L3T4-deficient cell line HT-2 after transfection with a Lyt-2 cDNA clone. Similarly, anti-L3T4 mAbs inhibited the IL-2 response of CD4-transfected HT-2 cells. These inhibitory effects of anti-CD4 and anti-CD8 mAbs occur on normal T lymphocytes, since they also were observed with CD4+ and CD8+ T-cell blasts, and are specific for IL-2 responses, since IL-4 responses of CD4- and CD8-transfected HT-2 cells were not affected by the anti-CD4 and anti-CD8 mAbs. The inhibitory effects of anti-CD4 or anti-CD8 mAbs could not be explained by interference with IL-2 binding and depended on CD4 and CD8 crosslinking, because F(ab')2 or Fab plus crosslinking second antibody, but not Fab alone, were effective. A mutant Lyt-2 molecule lacking the cytoplasmic region that mediates p56lck binding could not mediate the inhibitory effect upon crosslinking. These results suggest that CD4 and CD8 mediate negative regulation of T-cell IL-2 responses via cytoplasmically associated p56lck.

Animals↗

PubMed1992

Purification of nitric oxide synthase from bovine brain: immunological characterization and tissue distribution.

Nitric oxide (NO) synthase (EC 1.14.23) was purified to homogeneity from bovine cerebrum. The molecular weight of NO synthase was estimated to be 150 kDa by both SDS/PAGE and gel filtration at high salt concentration. For activity, the enzyme required NADPH, Ca2+, calmodulin and tetrahydrobiopterin as cofactors. Rabbit polyclonal antibody to bovine brain NO synthase reacted with 150 kDa NO synthase in various bovine and rat organs, including the brain, pituitary and adrenal glands, but not with that in stimulated macrophages, indicating that there are at least two immunologically distinct NO synthases.

Amino Acid Oxidoreductases↗

PubMed1992

Identification of human placental leucine aminopeptidase as oxytocinase.

Human placental leucine aminopeptidase (P-LAP) was purified from retroplacental serum for the first time by serial chromatography on columns of Matrex Blue A, DEAE-Sepharose CL-6B, phenyl-Sepharose 4B, chelating-Sepharose, and Sepharose CL-6B. The purified P-LAP was apparently homogeneous on sodium dodecyl sulfate-polyacrylamide gel electrophoresis and the apparent molecular weight (Mr) was estimated to be 210,000. By comparing P-LAP activity with cystine aminopeptidase activity, we concluded that both activities were shared by the same molecule. We also examined the hydrolytic activity of P-LAP using naturally occurring peptide hormones and found that the enzyme hydrolyzed oxytocin, vasopressin, and angiotensin III. These results suggest that P-LAP shows oxytocinase activity and plays an important role in the regulation of the plasma level of these hormones during pregnancy.

Chromatography, Gel↗

PubMed1992

Active-site residues of the transpeptidase domain of penicillin-binding protein 2 from Escherichia coli: similarity in catalytic mechanism to class A beta-lactamases.

By means of amino acid sequence alignment with class A beta-lactamases, the residues essential for the catalytic activity of the peptidoglycan transpeptidase of penicillin-binding protein 2 (PBP2) have been predicted to be Lys333, Asp447, and Lys544, in addition to the acylation site residue for the acyl-enzyme mechanism, Ser330. Accordingly, these residues were replaced by site-directed mutagenesis, and the resultant mutants were examined as to penicillin-binding activity and genetic complementation, which represent only the acylation step and the total reaction during transpeptidation, respectively. All the mutants at position 333 showed the complete loss of both the binding and complementation activities. Most of the mutants at position 447 retained the binding activity but lost the complementation activity, the exception being the D447E mutant, which retained both. The binding rates for various penicillins of the D447N mutant, which had lost the complementation activity, were almost identical to those of the wild type. The binding of the mutants at position 544 tended to require a higher penicillin concentration, and that of the K544H mutant required a lower pH. When the roles of the counterpart residues, Lys73, Glu166, and Lys234, in class A beta-lactamases were considered, the results suggested that Lys333 and Asp447 are essential for the acylation and acyl-transfer steps, respectively, and that Lys544 stabilizes the Michaelis complex through its side-chain positive charge.

Amino Acid Sequence↗

PubMed1992

Clearance of HBsAg in seven patients with chronic hepatitis B.

The natural history of chronic hepatitis B patients who spontaneously cleared serum HBsAg was investigated. A total of 351 patients with chronic hepatitis B were observed in our hospital for at least 3 yr. Seven of these patients became HBsAg negative during the follow-up period. HBsAg disappeared within 6 mo (range = 11 to 169 days, mean = 70 days) after acute elevation of ALT. ALT levels as high as 500 IU were found in three patients, whereas such elevation was not demonstrated in the other four patients. After the disappearance of HBsAg, ALT levels returned to normal in all patients. With one exception, all patients seroconverted to antibody to HBsAg; however, hepatitis B virus DNA remained detectable in serum using the polymerase chain reaction in five patients. The titer of percent inhibition of antibody to HBcAg gradually decreased to less than 70% when a 1:200 dilution of the serum of six patients was used. Four of the patients had active liver disease develop: two had chronic active hepatitis and two had cirrhosis. Three of these four patients subsequently had hepatocellular carcinoma develop. These findings suggest that patients may suffer complications of chronic hepatitis even after normalization of transaminase activities and after the clearance of HBsAg. Thus hepatitis B virus should be considered as a possible factor associated with hepatocellular carcinoma even in the absence of HBsAg, particularly if serum hepatitis B virus DNA persists.

Base Sequence↗

PubMed1992

Anaerobic metabolism as an indicator of aerobic function during exercise in cardiac patients.

To determine whether patients with heart disease depend more than normal subjects on anaerobic metabolism to perform the same level of exercise, the anaerobic threshold, slope of the increase in carbon dioxide output with respect to oxygen uptake (delta VCO2/delta VO2) and the slope of the increase in oxygen uptake with respect to the increase in work rate (delta VO2/delta WR) both below and above the anaerobic threshold during exercise were evaluated. A total of 106 patients with chronic heart disease and 42 healthy subjects performed a symptom-limited incremental exercise test in a ramp pattern on a cycle ergometer. Peak oxygen uptake was significantly lower in the patients with heart disease than in the normal subjects. The anaerobic threshold, which was 20 +/- 4.6 ml/min per kg in normal subjects, decreased significantly with progressing severity of functional class: 16 +/- 2.4, 14.1 +/- 2.5 and 11.3 +/- 1.5 ml/min per kg, respectively, in patients in class I, class II and class III. The slope of delta VO2/delta WR, which represents the degree of aerobic metabolism, was also decreased both below and above the anaerobic threshold with increasing severity of heart disease. delta VCO2/delta VO2 below the anaerobic threshold was approximately 0.9 (p = NS between normal subjects and patients). However, delta VCO2/delta VO2 above the anaerobic threshold became steeper with increasing severity of heart disease: 1.37 +/- 0.17 in normal subjects versus 1.55 +/- 0.24, 1.67 +/- 0.3 and 1.8 +/- 0.35 respectively, in patients in functional class I, class II and class III.(ABSTRACT TRUNCATED AT 250 WORDS)

Aerobiosis↗

PubMed1992

True pulmonary carcinosarcoma (squamous cell carcinoma and chondrosarcoma). A case report.

True pulmonary carcinosarcoma (squamous cell carcinoma and chondrosarcoma) originating in the right lower lobe in a 62-year-old Japanese male is reported. The tumor, measuring 5.5 x 3.5 x 3.5 cm, was markedly necrotic and its apex protruded into the bronchial lumen. Light microscopy showed that the tumor was composed of squamous cell carcinoma with sarcomatous spindle or polygonal cell proliferation and true chondrosarcoma. Immunohistochemically, the cytoplasm of numerous cells of the squamous cell carcinoma component was stained with anti-cytokeratin (PKK 1) and the cytoplasmic membrane with anti-epithelial membrane antigen (EMA). Although sarcomatous regions were stained with anti-vimentin (vimentin) and no tumor cells were reactive for EMA, a few tumor cells were positive for PKK 1. The cytoplasm of numerous chondrosarcoma cells was positively stained for vimentin and S-100 protein. Based on these findings, we concluded that the present tumor was a true carcinosarcoma composed of squamous cell carcinoma with sarcomatous regions and true chondrosarcoma.

Aged↗