Biomedical subjects

H Katoh

Publications and source records attributed to H Katoh.

At least 163 records · Page 9Linked to original sources

PubMed1999

Characterization of a surface membrane molecule expressed by natural killer cells in most inbred mouse strains: monoclonal antibody C9.1 identifies an allelic form of the 2B4 antigen.

A newly generated monoclonal antibody (mAb C9.1) described in this study identifies a surface membrane molecule that is involved in the lytic programme of activated natural killer (NK) cells. This conclusion is based on the facts that, first, this antigen was expressed on the vast majority of surface immunoglobulin (sIg)- CD3- CD4- CD8- spleen lymphocytes, albeit it was also present on minor subsets of sIg+ B (approximately 7%) and CD3+ T (approximately 2%) lymphocytes; second, that all splenic NK activity was contained within the C9.1+ cell population, and was almost totally abolished by treatment of spleen cells with mAb C9.1 and complement; third, that mAb C9.1 was capable of increasing interleukin-2-cultured and in vivo polyinosinic:polycytidylic acid-activated, NK cell-mediated, antibody-redirected lysis, but not freshly isolated NK cell-mediated killing. Furthermore, the strain distribution of the C9.1 antigen was shown to be antithetical to that of the 2B4 antigen already described as a molecule associated with major histocompatibility complex-unrestricted killing mediated by activated NK cells. The gene encoding C9.1 antigen was linked to the Akp1 isozyme locus on chromosome 1 close to the 2B4 gene. Although C9.1 and 2B4 were monomeric glycoproteins of 78 000 MW and 66 000 MW, respectively, removal of N-linked sugars from both antigens by endoglycosidase F yielded identical protein backbones of 38 000 MW. Thus, all of these results suggest that mAb C9.1 recognizes an allelic form of the 2B4 antigen. However, the detection of mAb C9.1-reactive antigen on a minor subset of B cells may suggest a possible reactivity of mAb C9. 1 with some product of other members of the 2B4 family genes.

Animals↗

PubMed1999

Clinical evaluation of the effect of percutaneous transluminal angioplasty and intra-arterial papaverine infusion for the treatment of vasospasm following aneurysmal subarachnoid hemorrhage.

The clinical efficacy of percutaneous transluminal angioplasty and intra-arterial papaverine infusion for treatment of vasospasm following subarachnoid hemorrhage was investigated. Between 1990 and 1993, 84 patients were treated for cerebral vasospasm in National Defense Medical College Hospital. Angioplasty was performed for asymptomatic vasospasm in 18 patients and for symptomatic vasospasm in 12 patients. Intra-arterial papaverine infusion was performed for asymptomatic vasospasm in 10 patients and for symptomatic vasospasm in four patients. The other 40 patients were treated with standard conservative therapy including hypervolemic and hypertensive hemodilution. The outcomes of these patients were analyzed using the Glasgow Outcome Scale. The outcome tended to be better for patients treated with angioplasty, but not for those treated with papaverine infusion, than for those treated conservatively. Recurrence of vasospasm was more frequent after papaverine infusion than after angioplasty. Undesirable complications such as abrupt development of unconsciousness were experienced during papaverine infusion but not during angioplasty. We conclude that percutaneous transluminal angioplasty is superior to intra-arterial papaverine infusion for prevention and treatment of vasospasm following aneurysmal subarachnoid hemorrhage.

Angioplasty, Balloon↗

PubMed1999

Improved techniques of applying fibrin glue in lung surgery.

To enhance the adhesive property of fibrin glue, two techniques were developed. The first is an improvement of the conventional layer method, and the second is a further improvement of the first technique. Their adhesive properties were tested in canine lungs in two phases. In phase 1 of the experiment, two new techniques were compared with the conventional methods in the retrieved lung. In phase 2 of the experiment, the second technique examined how its adhesive properties changed after treatment comparing them with gelatin-resorcinol-formaldehyde-glutaraldehyde (GRFG) glue. In phase 1, the first technique showed a 3-fold enhancement of the adhesive properties as compared with the conventional methods, and with the second technique the adhesive properties were further improved by more than 2-fold in the retrieved canine lung. In phase 2, it was revealed that the bursting pressure of both the second new technique and GRFG glue was eventually equal, and enough to close the cut surface of the lung. In the clinical setting, two techniques showed a safe and satisfactory performance in closing the cut surface of the lung. Due to the low toxicity of fibrin glue and absorbable material, these two techniques, especially the second technique, provide better circumstances for the healing of lung injury.

Animals↗

PubMed1999

Bcl-2 expression in non-small cell lung cancers: higher frequency of expression in squamous cell carcinomas with earlier pT status.

Abnormal expression of the bcl-2 gene product (Bcl-2) has been found in a wide variety of tumors, including lung cancer. In the present study, a total of 116 tumor specimens from surgically resected non-small cell lung cancer (NSCLC) patients, that were previously studied for p53 protein expression, were analyzed with immunohistochemistry for Bcl-2 expression. Forty (34%) of 116 tumor specimens showed Bcl-2 expression, which was found to occur more frequently in males than females (p = 0.049) and to be associated with smoking (p = 0.047). Bcl-2 expression was more frequently observed in squamous cell carcinomas (27 of 51, 53%) than in adenocarcinomas (12 of 55, 22%; p = 0.002), and in pT1 tumors (11 of 13, 85%) than in pT2 and pT3 tumors (16 of 38, 42%) in squamous cell carcinomas (p = 0.01). Bcl-2 expression did not correlate either with p53 protein status. We compared Bcl-2 expression in primary tumors and metastatic tumors of regional lymph nodes. Of 11 cases with Bcl-2-negative primary tumors, 10 were Bcl-2-negative in metastatic tumors except 1 case. In contrast, of 10 cases with Bcl-2-positive primary tumors, 6 lost Bcl-2 expression in metastatic tumors, while the remaining 4 cases still showed Bcl-2 expression in metastatic tumors. In the 89 potentially curatively treated patients, those with Bcl-2-positive and Bcl-2-negative tumors did not show a significant difference in survival (5-year survival rates, 56 and 42%, respectively, p = 0.2 by the generalized Wilcoxon test). These data indicate that Bcl-2 expression is frequently observed in squamous cell carcinomas with early pT status, and that it does not predict prognosis of patients with NSCLC.

Carcinoma, Non-Small-Cell Lung↗

PubMed1999

Differences in the sensitivity to UVB radiation of two cultivars of rice (Oryza sativa L.) based on observation of long-lived radicals.

Free radicals with a long lifetime were observed in the leaves of two rice cultivars (Oryza sativa L.), Sasanishiki (UVB resistant) and Norin-1 (UVB sensitive), by electron spin resonance spectroscopy. The leaves of both cultivars grown with visible light show very similar ESR spectra composed of radical 1 (R1) and radical 2 (R2), which may be attributable to P700 cation radicals in the reaction center of photosystem I, and tyrosine cation radicals in the reaction center of photosystem II, respectively. The ESR spectrum composed of R1 and R2 radicals in the leaves of Sasanishiki grown under visible light with supplemental UVB was similar to that in the plant grown without supplemental UVB. On the other hand, the amount of R2 radicals in the leaves of Norin-1 grown under visible light with supplemental UVB was significantly smaller than that in the plant grown without supplemental UVB. It is suggested that the loss of R2 radicals in Norin-1 upon UVB irradiation is related to the instability of the plant.

Electron Spin Resonance Spectroscopy↗

PubMed1999

Biochemical diagnosis of aortic dissection: from bench to bedside.

Aortic dissection is an acute cardiovascular disease associated with high mortality and morbidity. Although uncommon, recent studies have shown that the incidence of this catastrophic disease is steadily increasing. Unfortunately, the disease is still not well recognized on clinical presentation due to lack of specific signs and symptoms. As early diagnosis and initial management are critical for survival, we focused on developing a biochemical diagnostic approach for this disease given its meritorious properties in use in the acute clinical situation and additional projected combined use with established imaging modalities. Studies using an assay developed against smooth muscle myosin heavy chain, a protein which is released from the aortic medial smooth muscle cells on insult to the aortic wall, showed promising results for use of this assay in the diagnosis of aortic dissection. The background of this pioneering assay in addition to its clinical use are discussed in this review.

Acute Disease↗

PubMed1999

[Optimal length of nasopharyngeal airway and its correlation with height and body weight].

We studied 26 patients (11 males and 15 females) undergoing elective surgery under general anesthesia. The purpose of this study was to decide how long the length of nasopharyngeal airway should be by measuring distance A (permitting airway obstruction to be released), distance B (giving the most effective ventilation), and distance C (between nostril and arytenoid). The values of distance A in male group and female group were 12.73 +/- 0.85 cm and 11.70 +/- 0.75 cm, respectively. The values of distance B were 14.55 +/- 0.96 cm in male group and 13.93 +/- 1.12 cm in female group. The values of distance C were 18.84 +/- 0.90 cm in male group and 17.40 +/- 0.97 cm in female group. This showed that it is necessary to advance the nasopharyngeal airway about 2 cm from the distance A to give the most effective ventilation to the patients with airway obstruction. Therefore, most of standard nasopharyngeal airways commercially available are too short. In addition, the distance B has no correlation with height and body weight and it is difficult to predict the optimal length of the airway.

Anesthesia, General↗

PubMed1999

[Anesthesia in a patient with epidermolysis bullosa].

Epidermolysis bullosa hereditaria, a rare inherited disorder presents clinically with recurrent cutaneous blister formation with possible involvement of mucous membrane and organs following minimal trauma. The sequelae of this disease pose significant anesthetic problems to operating room staffs. We describe the anesthetic management of a 32-year old woman with epidermolysis bullosa hereditaria who underwent palmar skin graft using regional anesthesia, and discuss the problems associated with this disease.

Adult↗

PubMed1999

Selective distal splenorenal shunt without requiring splenopancreatic disconnection with the use of the external iliac vein graft: a preliminary report.

BACKGROUND: Distal splenorenal shunt (DSRS) with splenopancreatic disconnection (SPD) is an ideal operation for permanent control of variceal bleeding. However, it is a very complicated procedure, and DSRS without SPD has a functional disadvantage: It gradually loses its selectivity and portal blood flow. To overcome these conditions, we designed a new technique--modified DSRS, which is easy to perform and maintains long-term selectivity of the shunt. METHODS: Modified DSRS was performed by using an external iliac vein graft without treating small pancreatic tributaries of the splenic vein. It was applied in 4 cases, and shunt patency and selectivity were examined by angiography during follow-up periods (6-76 months). RESULTS: Modified DSRS was technically more feasible and less complicated than DSRS with SPD. Every attempt was successful. There was no operative mortality, and all the patients were discharged from the hospital in good condition. The shunts were patent in all of them, and the selectivity of the shunt was maintained better in comparison to standard DSRS. CONCLUSIONS: Modified DSRS is a much easier and safer technique than standard DSRS. We consider this procedure to be the best method for surgical management of portal hypertension causing esophageal and gastric varices.

Esophageal and Gastric Varices↗

PubMed1999

[Left ventricular relaxation in lone atrial fibrillation and atrial fibrillation with heart disease].

Atrial fibrillation with organic heart disease shows a steady value for the time constant of left ventricular isovolumetric relaxation (TC), whereas left ventricular contractility varies from beat to beat. However, there is no report on left ventricular relaxation in lone atrial fibrillation. This study assessed left ventricular relaxation in 5 patients with lone atrial fibrillation, 3 with ischemic heart disease and one with hypertrophic cardiomyopathy. Left ventricular pressure was recorded at 3 msec intervals, with a high fidelity micromanometer-tipped catheter. Maximal positive dP/dt (dP/dtmax) and TC of isovolumetric left ventricular relaxation period [P(t) = (P0-P infinity) exp (-t/TC) + P infinity] were measured as indices of left ventricular contractility and left ventricular relaxation, respectively. Correlation coefficients of dP/dtmax and TC versus the ratio of the preceding to the pre-preceding RR-interval (RR2/RR1) were calculated. A good correlation was found between dP/dtmax and RR2/RR1 in all patients (r = 0.71-0.84, p < 0.0001). No correlation between TC and RR2/RR1 was found in patients with atrial fibrillation with organic heart disease, but a good correlation was found between TC and RR2/RR1 in patients with lone atrial fibrillation (r = 0.74-0.95, p < 0.0001). The correlation between TC and RR2/RR1 is well preserved in lone atrial fibrillation. The mechanism of the variation of TC with the RR2/RR1 interval in lone atrial fibrillation may be similar to the change of TC in postextrasystolic potentiation, which is attributed to the change of intracellular Ca2+ concentration. Absence of correlation between TC and RR2/RR1 interval may indicate that left ventricular relaxation is disturbed in patients with atrial fibrillation with organic heart disease.

Aged↗

PubMed1999

Leprosy in hypertensive nude rats (SHR/NCrj-rnu).

Since more than a decade ago, we have attempted to develop spontaneously hypertensive rats carrying the nude gene that permits high multiplication of Mycobacterium leprae. A congenic strain carrying nude (rnu) and hypertensive genes was produced using SHR/NCrj females and F344/NJcl-rnu males. Cross-intercross was carried out 12 times to establish the hypertensive nude rat congenic strain. As a result of the genetic monitoring test with NE12F2 generation rats, the genetic profile of the SHR/NCrj-rnu rats was the same as that of the SHR/NCrj rats except for the rnu gene. We have successfully developed a hypertensive congenic nude rat strain (SHR.F344Hfh11; SHR/NCrj-rnu). An increase in the blood pressure in nude rats was found to begin at a slightly delayed age when compared with their hairy litter mates. Both female and male rats showed the highest blood pressure at approximately 20 weeks of age--166 +/- 1.4 and 197 +/- 11 mm Hg in nude rats and 175 +/- 11 and 193 +/- 3.2 mm Hg in their hairy litter mates in female and male rats, respectively. In the present study, comparisons were made on the susceptibility to M. leprae in hypertensive SHR/NCrj-rnu and normotensive F344/NJcl-rnu rats. We have reconfirmed that hypertensive SHR/NCrj-rnu rats of the NE12F3 generation were highly susceptible to M. leprae. In the SHR/NCrj-rnu rats of both sexes excellent massive swelling due to multiplication of M. leprae was observed and, also, nodular lesions were produced in uninoculated fore feet and lips while those sites in the F344/NJcl-rnu rats showed only a slight swelling of the inoculated feet with mild nodular lesions. Although mild lymphocyte proliferation was seen only in the M. leprae-inoculated site with numerous bacilli and partial necrosis in the SHR/NCrj-rnu rats, at noninoculated sites, multiplication of M. leprae was only observed in the cells of the mononuclear phagocyte system. However, in F344/NJcl-rnu rats, lymphocyte proliferation with a few neutrophils was seen at the site of inoculated hind foot pads and everywhere at the site of multiplication of M. leprae. There was a wide difference in the susceptibility to M. leprae between the SHR/NCrj-rnu and the F344/NJcl-rnu rats.

Age Factors↗

PubMed1999

Laparoscopic treatment of cholecystocolonic fistula: report of a case preoperatively diagnosed by barium enema.

The authors present a case of cholecystocolonic fistula with no specific symptoms, such as severe diarrhea or pneumobilia, preoperatively diagnosed and treated by the laparoscopic approach. A preoperative barium enema demonstrated a cholecystocolonic fistula. The fistula was divided by the laparoscopic stapling technique. Important features in the management of this case are (1) preoperative diagnosis of the fistula by barium enema carried out for screening colorectal cancer, (2) dissection of the gallbladder from its bed before division of the fistula, and (3) use of the laparoscopic stapling technique to divide the fistula while preventing fecal soilage.

Barium Sulfate↗

PubMed1999

Long-term benefits for the quality of life after video-assisted thoracoscopic lobectomy in patients with lung cancer.

Quality of life (QOL) after video-assisted thoracic surgical (VATS) lobectomy remains to be defined. Forty-four consecutive patients with clinical stage I lung cancer underwent lobectomy by the VATS approach (n = 22 patients) or thoracotomy approach (n = 22 patients). Acute pain was quantitated by postoperative narcotic requirements and the need for epidural anesthesia. Long-term QOL was assessed by questioning patients about the presence of chronic chest pain, ongoing limitations in arm or shoulder function, time until return to preoperative activity, and satisfaction with the operation. Patients who underwent VATS lobectomy had significant decreases in both acute and chronic chest pain and time until return to preoperative activity. Patients also had more confidence regarding wound size and their overall impression of the operation. In this series, VATS lobectomy was associated with long-term benefits for the QOL in patients with lung cancer. However, the exact role of this approach should be defined by carefully-designed controlled trials studying long-term survival.

Adult↗

PubMed1998

Constitutively active Galpha12, Galpha13, and Galphaq induce Rho-dependent neurite retraction through different signaling pathways.

In neuronal cells, activation of a certain heterotrimeric G protein-coupled receptor causes neurite retraction and cell rounding via the small GTPase Rho. However, the specific heterotrimeric G proteins that mediate Rho-dependent neurite retraction and cell rounding have not yet been identified. Here we investigated the effects of expression of constitutively active Galpha subunits on the morphology of differentiated PC12 cells. Expression of GTPase-deficient Galpha12, Galpha13, and Galphaq, but not Galphai2, caused neurite retraction and cell rounding in differentiated PC12 cells. These morphological changes induced by Galpha12, Galpha13, and Galphaq were completely inhibited by C3 exoenzyme, which specifically ADP-ribosylates and inactivates Rho. The tyrosine kinase inhibitor tyrphostin A25 blocked the neurite retraction and cell rounding induced by Galpha13 and Galphaq. However, tyrphostin A25 failed to inhibit the Galpha12-induced neuronal morphological changes. On the other hand, inhibition of protein kinase C or elimination of extracellular Ca2+ blocked the neurite retraction and cell rounding induced by Galphaq, whereas the morphological effects of Galpha12 and Galpha13 did not require activation of protein kinase C and extracellular Ca2+. These results demonstrate that activation of Galpha12, Galpha13, and Galphaq induces Rho-dependent morphological changes in PC12 cells through different signaling pathways.

ADP Ribose Transferases↗

PubMed1998

Automatic and simultaneous analysis of Lens culinaris agglutinin-reactive alpha-fetoprotein ratio and total alpha-fetoprotein concentration.

An automated analytical method for analyzing alpha-fetoprotein (AFP) carbohydrate chain microheterogeneity based on competitive reaction between lectin and anti-AFP monoclonal antibody in liquid phase is described. The antibody used binds to all species of AFP molecule without Lens culinaris agglutinin (LCA); however, its binding reaction to LCA-reactive AFP was inhibited by LCA. Sulfated tyrosine octamer was conjugated to the antibody, and sulfated tyrosine pentamer and peroxidase were conjugated to other monoclonal antibodies, respectively. Serum reacted with three anti-AFP monoclonal antibodies and LCA in liquid phases, and two types of immune complex were observed. The two types were separated directly by the liquid-phase binding assay system equipped with an anion-exchange column. Peroxidase activity of immune complex was determined fluorophotometrically. Total AFP concentration and the ratio of LCA-reactive AFP in samples were calculated simultaneously, using the sum of the two peaks and the ratio of peaks obtained by LCA inhibition to sum of two peaks. The results correlated well with conventional methods. The method is simple and convenient for routine clinical assays.

Antibodies, Monoclonal↗

PubMed1998

Determination of alpha-fetoprotein concentration based on liquid-phase binding assay using anion exchange chromatography and sulfated peptide introduced antibody.

A new immunoassay for alpha-fetoprotein based upon liquid-phase binding reactions is described. In this procedure, a sample that contains alpha-fetoprotein is mixed with a solution of two anti-alpha-fetoprotein monoclonal antibodies complexed with peroxidase and sulfated peptide, respectively. After incubation, immune complex is separated from other components by anion exchange column chromatography. Immune complex is quantified using fluorometric detection by peroxidase enzymatic activity. Peroxidase activity correlated with a alpha-fetoprotein with a 1:1 relationship. The stoichiometric immunoreaction allowed a large analytical range (0.4-7500 ng/ml) with a linear dose-response relationship, high sensitivity and good precision. Endogenous substances did not interfere with assay performance. Assay results showed good correlation with other established methods. These results indicate that the method is useful for clinical alpha-fetoprotein determinations.

Anions↗

PubMed1998

Liquid-phase binding assay of alpha-fetoprotein using a sulfated antibody for bound/free separation.

A rapid immunoassay using a sulfated antibody for bound/free separation in a liquid-phase binding assay is described. A first anti-alpha-fetoprotein monoclonal antibody was labeled with peroxidase (Fab'-POD) and a second monoclonal antibody was conjugated with polysulfated tyrosine peptide (Fab'-YS). The monoclonal antibodies and alpha-fetoprotein (AFP) were mixed, incubated, and analyzed directly by anion-exchange column chromatography. The amount of POD activity in the column effluent was determined fluorophotometrically. The bound (Fab'-POD + AFP + Fab'-YS) and free (Fab'-POD) forms of the conjugate were clearly and easily separated by ionic charge, and the free sulfated antibody (Fab'-YS) was not detectable fluorophotometrically. The elution position of the bound conjugate was adjusted by varying the length of the polysulfated tyrosine peptide. This method is convenient for antigen measurement because (1) only two modified antibodies are used in a buffer solution, (2) the concentration of antibodies and other assay conditions are easily set, (3) no solid phase is required, and (4) no washing is necessary.

Antibodies, Monoclonal↗

PubMed1998

p160 RhoA-binding kinase ROKalpha induces neurite retraction.

We previously reported that the activation of prostaglandin E receptor EP3 subtype caused neurite retraction via small GTPase Rho in the EP3B receptor-expressing PC12 cells (Katoh, H., Negishi, M., and Ichikawa, A. (1996) J. Biol. Chem. 271, 29780-29784). However, a potential downstream effector of Rho that induces neurite retraction was not identified. Here we examined the morphological effect of p160 RhoA-binding kinase ROKalpha, a target for RhoA recently identified, on the nerve growth factor-differentiated PC12 cells. Microinjection of the catalytic domain of ROKalpha rapidly induced neurite retraction similar to that induced by microinjection of a constitutively active Rho, RhoV14, whereas microinjection of the kinase-deficient catalytic domain of ROKalpha did not induce neurite retraction. This morphological change was observed even though C3 exoenzyme, which was known to inactivate Rho, had been preinjected. On the other hand, microinjection of the Rho-binding domain or the pleckstrin homology domain of ROKalpha inhibited the EP3 receptor-induced neurite retraction. These results demonstrate that ROKalpha induces neurite retraction acting downstream of Rho in neuronal cells.

Animals↗