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Biomedical subjects

T Akamatsu

Publications and source records attributed to T Akamatsu.

At least 127 records · Page 7Linked to original sources

[On the two types of voluntary admissions in Japan--including the issue of the competency to consent to admission].

Voluntary admissions are classified by four factors-limitation of discharge, limitation of actions, procedures of protection of human rights, prescription of the special law concerning with mental health. The voluntary admission prescribed in the Mental Health Law in Japan (NIN'I-NYUUIN) has all of these four factors. But we are using also the informal admission (JIYUU-NYUUIN), which is not prescribed in the Mental Health Law in Japan, and does not have limitation of discharge. The government has done several acts against the informal admission, and some disputants argued against it, but either logically or practically, it is beneficial to use the informal admission as the one that is distinguished from the voluntary admission, and the government should stop those acts immediately. Although one disputant argues that the informal admission should be prescribed in the Mental Health Law and should have procedures of protection of human rights, we should pursue complete voluntary admission, that is, the one that is similar to admission of medical or surgical patients, and that has neither of the four factors of voluntary admissions. And we should consider the competency to consent to admission. Some disputants argue with Zinermon v. Burch, the decision of the U.S. Supreme Court in 1990. But this decision necessarily did not argue that the patient should be tested whether competent or not before voluntary admission, and some argued that the decision should not be read expansively. On voluntary admission, the clinician should consider not only the competency of the patient, but also the therapeutic benefit of voluntary admission.

Commitment of Persons with Psychiatric Disorders↗

[Cardiac surgery using cardiopulmonary bypass in a patient with sickle-cell trait].

The sickle-cell gene is most concentrated in West Central Africa, the northeast corner of Saudi Arabia and East Central India. Sickle cell trait is the heterozygous condition for Hb S gene. Thirty to fifty per cent of their hemoglobin is Hb S and the remainder is Hb A. The sickle-cell crisis is induced by hypoxia, hypercarbia, acidosis, low flow condition, and hypothermia, which leads to vasoocclusion. A 39-year-old black man from Burkina Faso located in West Africa with left ventricular rupture was admitted for operation using cardiopulmonary bypass (CPB). He had been diagnosed as sickle-cell trait. The Hb S concentration was 36.2 per cent before operation with hemoglobin electrophoresis. During CPB, the minimum blood temperature was 31 degrees C and an aortic cross-clamp was not done. Total CPB time was 1 hour 31 minutes. Use of vasodilator and hyperventilation was effective. No neurological sequelae were observed.

Adult↗

[Aortic dissection after weaning from extracorporeal circulation].

Acute aortic dissection is a rare complication of cardiac surgery. But once it happens, its outcome is often miserable. We experienced this complication after discontinuing cardiopulmonary bypass (CPB). A 56-year old man with mitral regurgitation was referred for mitral valve replacement under CPB. After weaning from extracorporeal circulation (ECC), the right radial artery pressure decreased suddenly and its waveform became flat. After 5 minutes, dissection of the ascending aorta was diagnosed by transesophageal echocardiography (TEE). We started to prevent ischemic brain damage immediately, but a severe brain damage occurred. Its early diagnosis is necessary and the prevention of critical brain damage due to low perfusion of the blood is important for anesthetic management.

Aortic Dissection↗

Autoimmune chronic pancreatitis simulating pancreatic lymphoma.

A 51-yr-old man, who presented with diabetes mellitus, abdominal pain, inguinal lymphadenopathy, and diffuse enlargement of the whole pancreas on ultrasonography, was at first thought to have pancreatic lymphoma. Chemotherapy including steroid was carried out successfully, although the definitive diagnosis of lymphoma was not made. However, on follow-up, we realized that both laboratory findings, such as hyperglobulinemia and autoantibody-positive results, and radiographic features in this case were very similar to those of a case of autoimmune pancreatitis recently reported by Yoshida et al. (Dig Dis Sci 1995;40:1561-8). When the disease recurred, therefore, treatment with steroid alone was performed with an excellent result. We report a case of autoimmune pancreatitis simulating primary pancreatic lymphoma.

Autoimmune Diseases↗

+Gz acceleration affects the trace minerals zinc, copper, and chromium in serum and urine of humans.

BACKGROUND: Research investigating the relationship between physical training and trace mineral concentrations has primarily focused on athletes. Few investigations, however, have specifically examined the alterations of trace mineral concentrations occurring in humans exposed to +Gz acceleration. Exercise alters mineral content; G-exposure is a form of exercise; therefore, G-exposure may elicit changes in mineral content. HYPOTHESIS: Exposure to +Gz acceleration may affect the concentrations of the trace minerals zinc, copper, and chromium in human serum and urine. METHODS: Blood samples were obtained from 7 men and 3 women, before and immediately after +Gz acceleration. Urine samples were obtained before, 30 min after, and 2 h after +Gz acceleration. RESULTS: The serum zinc concentration was significantly different after +Gz acceleration, decreasing from 90.6 +/- 21.0 micrograms.dl-1 to 80.8 +/- 14.4 micrograms.dl-1. The serum copper concentration was also significantly altered immediately after +Gz acceleration, decreasing from 111.7 +/- 27.5 micrograms.dl-1 to 98.5 +/- 35.2 micrograms.dl-1. The urinary zinc and copper concentrations, and the serum chromium concentration were not significantly affected by +Gz acceleration. CONCLUSIONS: The circulating levels of these minerals presumably change as they are transported to the tissues requiring greater amounts due to the increased physiological work associated with +Gz acceleration.

Acceleration↗

Proliferative markers in gastric carcinoma and organoid differentiation.

The present study was undertaken to elucidate the relationship between the distribution of potentially proliferative tumor cells and the organoid differentiation of tumor cells in gastric carcinomas. One hundred four specimens of surgically removed human gastric carcinomas, including 68 and 36 specimens of early and advanced carcinomas, respectively, were studied by using a battery of histochemical techniques. Serial 3-microns thick paraffin sections were stained by galactose oxidase-cold thionine Schiff-paradoxical concanavalin A staining (GOCTS-PCS), or were immunostained for pepsinogen types I and II, lysozyme, and proliferating cell nuclear antigen (PCNA). In addition, to identify proliferative tumor cells parts of fresh carcinoma tissues were incubated in a solution containing bromodeoxyuridine (BrdU), embedded in paraffin, and immunostained for BrdU. The results indicated that in intramucosal carcinoma tissues showing organoid differentiation the proliferative tumor cells were located predominantly between the covering epithelial cell type tumor cells and the glandular mucous cell type tumor cells, and the disturbance in the distribution of proliferative cells coincided with the submucosal invasion.

Biomarkers, Tumor↗

Characterization of development-specific, cell type-specific mouse testicular antigens using testis-specific polyclonal antibodies.

Antisera were raised by immunizing rabbits with mouse testicular germ cells, and absorbed in vivo by injection into castrated male whole mice to obtain a specific antiserum which reacted with mouse germ cells. The expression of mouse testis-specific antigenic macromolecules was then studied immunochemically with the antiserum. Approximately 20 antigenic macromolecules with molecular weights ranging from 26 to 110 kD were detected in the normal adult testis. At least 12 of these were differentiation-specific antigens appearing during development of germ cells, while others were expressed in testicular germ and/or somatic cells or detected only in mature spermatozoa. This technique for raising testis-specific antisera could be useful for isolation of cDNA clones encoding their antigens, as well as for investigation of the physiological roles of these molecules in germ cell differentiation at the molecular level.

Animals↗

Recent studies of the centrifugal blood pump with a magnetically suspended impeller.

We have been developing a centrifugal blood pump with a magnetically suspended impeller. To improve pump efficiency, we investigated the pump performances of many kinds of impeller vanes and diffusers, as well as the flow in the gap between the impeller discs and the pump housing. We found the vanes and the diffusers with high pump efficiency; however, high efficiency does not mean low hemolysis. It seems important to prevent generation of small-sized eddies with high shear stress. Hemolysis tests are carried out to find the optimal vane profile and gap clearance. The index of hemolysis and temperature change of our pump is better than those of the Biopump. Short-term in vivo studies show that the layer of white thrombi adheres to the machined rough surface of polycarbonate, which composes the narrow gap (0.2 mm) between the impeller and the pump wall, but a smooth surface coated with silicon prevents adhesion of that layer.

Animals↗

Distribution of the Kexin family proteases in pancreatic islets: PACE4C is specifically expressed in B cells of pancreatic islets.

The distribution of Kexin family proteases in adult rat pancreatic islets was investigated by immunohistochemical means using a series of specific antibodies specific for PC1, PC2, PC6, Furin, PACE4A and a recently identified member of the Kexin family, PACE4C. PACE4C expression was limited to B cells of the pancreatic islets. PC2 was found in A and in some D cells more than in B cells and PC1 was evident only in B cells. Furin and PC6 were weakly and evenly expressed in the entire islet. PACE4A was hardly found in the islets. These findings indicated that individual Kexin family proteases are uniquely distributed in the islets and suggested that these proteases share roles in these cells as follows: PC2 is involved in the peptide hormone precursor processing in A cells and in D cells, and PACE4C, PC1 and PC2 (mainly PACE4C and PC1) are responsible for the processing event(s) specific to B cells.

Animals↗

[Clinical and etiological studies of IgG antibodies to Helicobacter pylori detected by enzyme-linked immunosorbent assay].

Recently, Helicobacter pylori (H. pylori) has been reported that it is involved in the pathogenesis of duodenal ulcer and might be a risk factor for gastric cancer. To diagnose H. pylori infection, detection of serum antibody is much less stressful and more cost effective than gastric biopsy. Using a serological method, We have reported that the prevalence of serum anti-H. pylori IgG was elevated with age among healthy subjects and over 80% among elder people. Thus, it would be essential to investigate the specificity of the ELISA system (PirikaplateG Helicobacter) for the detection of serum anti-H. pylori IgG. Sera from healthy controls (n = 653) and patients (n = 116) with gastritis, gastric ulcer, and/or duodenal ulcer were studied for anti-H. pylori IgG. Cross reactivity of the anti-H. pylori IgG with closely related bacteria was less than 10% (with C. jejuni: 7.4%, C. laridis: 0.2%, E. coli: -2.4%) in the ELISA system. Anti-H. pylori IgG from both normal controls and the patients were equally neutralized with the extract of H. pylori. Of note was that the prevalence of anti-H. pylori IgG among patients was significantly higher than that among normal controls. Referring to the diagnoses by gastric biopsy, the sensitivity and specificity of this ELISA were 88.2% and 74.2%, respectively. We also demonstrated the clinical usefulness of this ELISA by receiver operating characteristic curve (ROC). Interestingly, several healthy subjects positive for serum anti-H. pylori IgG were voluntarily subjected to gastric biopsy, and proved positive for H. pylori infection.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

Identification of targeting proteinase for rat alpha 1-macroglobulin in vivo. Mast-cell tryptase is a major component of the alpha 1-macroglobulin-proteinase complex endocytosed into rat liver lysosomes.

The alpha 1-macroglobulin-proteinase complex endocytosed into rat liver lysosomes was purified by a series of column chromatographic steps on concanavalin A-Sepharose, Sephacryl S-300, DEAE-cellulose and TSK gel DEAE-5PW columns. The complex contained no detectable alpha 2-macroglobulin. Studies on the substrate specificity indicated that the complex had tryptase-like activities towards various synthetic substrates, but no elastase, chymotrypsin, cathepsin-B and cathepsin-L activities. The proteinase activity was completely inhibited by di-isopropyl fluorophosphate, leupeptin and antipain, indicating that the proteinase bound to alpha 1-macroglobulin is a serine proteinase. Two protein bands (62 and 59 kDa) of the complex were labelled with [3H]diisopropyl fluorophosphate and both bands cross-reacted with anti-(mast-cell tryptase)antibody. These results suggest that mast-cell tryptase is a major targeting proteinase for alpha 1-macroglobulin in vivo. The main alpha-macroglobulin-proteinase complex in the adjuvant-treated rats was also the alpha 1-macroglobulin-tryptase complex, even though the plasma level of alpha 2-macroglobulin was elevated.

Amino Acid Sequence↗

Inhibition of mitogen-induced response of human peripheral blood mononuclear cells by bucillamine, a new antirheumatic sulfhydryl drug.

The mechanism of action of bucillamine, [N-(2-mercapto-2-methylpropionyl)-L-cysteine] (BC), a novel antirheumatic drug that is used in patients with rheumatoid arthritis (RA), was compared with that of D-penicillamine (DP). BC inhibited phytohemagglutinin (PHA)-induced DNA synthesis of peripheral blood mononuclear cells (PBMCs) in a dose-dependent manner, and this inhibition occurred both in the presence and absence of copper, whereas DP-induced inhibition required the presence of cupric ions. Significant inhibition of DNA synthesis was observed at a BC concentration of 10 micrograms/ml. The disulfide form of BC, but not DP disulfide, suppressed the proliferation of PBMCs. After preincubation of human peripheral blood T lymphocytes or Møs with BC or DP, these cells were combined and the overall PHA response was estimated. Inhibition of the PHA response was observed following pretreatment of either T lymphocytes or Møs with BC, whereas inhibition was attained only when T lymphocytes were pretreated with DP and copper. As sulfhydryl agents produce hydrogen peroxide in the presence of cupric ions, the effect of catalase on DP- and BC-induced inhibition of PBMC DNA synthesis was examined. Catalase partially reversed the BC-induced inhibition of DNA synthesis of PBMCs, and it restored the inhibition by DP and copper almost to the control level. These results suggest that BC suppresses the function of both T lymphocytes and Møs in the mitogen response of PBMCs, whereas the action of DP is targeted at T lymphocytes.

Anti-Inflammatory Agents, Non-Steroidal↗

Ultrastructure of the ootype of the lung fluke Paragonimus ohirai (Digenea, Troglotrematidae) in mated and single-infection worms.

The ootype of Paragonimus ohirai was studied by both scanning and transmission electron microscopy. The ootype wall in 20-week-old worms from single infections was similar in its epithelial cell architecture and components to that of mated worms at 10 weeks postinfection. The lining epithelium consisted of a single layer of nucleated cells. The cytoplasm displayed a variety of organelles such as occasional Golgi complexes, well-developed annulate lamellae, frequent lysosomes, abundant mitochondria, and numerous ribosomes, suggesting high activities of intracellular synthesis and digestion. The former three organelles were generally located in the apical cytoplasm protruding into the lumen and may be significant in participating in regulation of egg formation. The present comparative studies suggest that the ootype epithelium can mature even by single infections and that the organized intracellular activities remain developed in single worms even after prolonged infection.

Animals↗

Pigmentary retinopathy with nephrotic syndrome, Ménétrier's disease, and diabetes mellitus.

A patient with pigmentary retinopathy, nephrotic syndrome, Ménétrier's disease, and diabetes mellitus is presented. Other complications were congestive heart failure, hypothyroidism, hypertension, and hypertriglyceridemia. Hypogenitalism was also suspected. Pigmentary retinopathy is known to associate with many systemic diseases, which are classified into several syndromes. This case superficially resembles Alström's disease due to the common characteristics of pigmentary retinopathy, diabetes mellitus, renal disease, and hypogenitalism. But clinically and histologically, there are distinct differences. To our knowledge, this association has never been reported.

Consanguinity↗

Localization of peroxidase activity in tegumental, muscle, and parenchymal cells of the lung fluke Paragonimus miyazakii (Digenea: Troglotrematidae).

The distribution and localization of peroxidase activity were examined in adults of Paragonimus miyazakii in sections stained with 3,3'-diaminobenzidine in the presence of hydrogen peroxide. Peroxidase activity was detected in tegumental cell mitochondria. With cell development, the reaction intensity became greater. Activity extended from the inner membrane (undifferentiated stage) to the intermembrane space (differentiating stage) and then to the matrix (differentiated stage). Mitochondria with the most intense reaction were densely distributed in the outer syncytial region. Strong activity was also present in mitochondria of muscle cells and in those of Type II parenchymal cells. Intermembrane spaces were the predominant site of this activity. Characteristically, both 10 mM azide and 1 mM cyanide were mildly effective in the inhibition of mitochondrial peroxidase activity in each cell type.

3,3'-Diaminobenzidine↗

Serious arrhythmias coinciding with alteration of consciousness in aircrew during +Gz stress.

The Japanese Air Self Defense Force has been conducting high-G training to enhance the +Gz tolerance of F-15 and F-4 fighter pilots since 1981. All the trainees have received ECG monitoring during the +Gz stress, both for safety and for medical evaluation. Various arrhythmias have been found previously, but most of the pilots who developed them were qualified for fighter aircraft because these arrhythmias were considered as non-hazardous for flight safety. Rarely, cases of aeromedically "serious" arrhythmias were observed with alteration of consciousness during the centrifuge ride. Three cases of sinoatrial block and one case of ventricular tachycardia were reviewed with their aeromedical dispositions. Imbalance of autonomic nerves induced by high +Gz is discussed as a possible etiology. The importance of ECG monitoring during centrifuge training is reemphasized as a means of medical evaluation of fighter pilots.

Adult↗

Establishment of Epstein-Barr virus-associated lymphoma cell line SUBL with t(2;3)(p11;q27) from a liver transplant patient.

A new lymphoma cell line, designated SUBL, was established from a Japanese patient with Epstein-Barr virus (EBV)-associated lymphoma, which developed during FK 506 therapy after liver transplantation. This cell line has undergone 80 passages over a period of 22 months. The cultured cells were positive for CD19, CD20, CD21, CD22, CD23, and HLA-DR, and negative for CD10 and surface immunoglobulins. Immunoglobulin gene analysis revealed rearrangements of JH and JK. T-cell antigens or T-cell receptor gene rearrangements were not observed on the cell line. The SUBL cells were positive for Epstein-Barr virus nuclear antigen (EBNA). The EBV genome was detected in the original tissue and the cell line by the in situ hybridization method. These data indicate that this cell line represents the B-cell lineage at a pre-B-cell stage. SUBL cells showed successful heterotransplantation to mice with severe combined immunodeficiency (SCID). Chromosomal analysis revealed the karyotype 46,XY,t(2;3)(p11;q27). Molecular studies showed that c-myc, N-myc, and bcl-2 were not rearranged. This cell line will provide a useful in vitro system to study the relationship between chromosomal abnormalities and the activation of cellular oncogenes.

Animals↗