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Biomedical subjects

E Sada

Publications and source records attributed to E Sada.

At least 37 records · Page 2Linked to original sources

Detection of human herpesvirus 6 and human herpesvirus 7 in the submandibular gland, parotid gland, and lip salivary gland by PCR.

In order to define the major sites of persistence of human herpesvirus 6 (HHV-6) and HHV-7, PCR with DNAs from more than 100 specimens of 3 different salivary glands was performed. HHV-6 DNA was detected in 52 (88.1%) of 59 submandibular gland, 17 (63.0%) of 27 parotid gland, and 9 (52.9%) of 17 lip salivary gland specimens. On the other hand, HHV-7 DNA was detected in 59 (100%) of 59 submandibular gland, 23 (85.2%) of 27 parotid gland, and 10 (58.8%) of 17 lip salivary gland specimens. These findings demonstrate that salivary glands are a site of persistent infection of both HHV-6 and HHV-7 and that among the three types of salivary gland examined, the submandibular gland is the primary one in which these herpesviruses, especially HHV-7, persist.

Herpesvirus 6, Human↗

A new cutaneous nerve fiber connection with the frontal nerve in the frog Rana esculenta: a morphological study.

The frontal nerve arises from the frontal organ, which represents the extracranial component of the pineal complex in some lower vertebrates, and interconnects the frontal organ with the epiphysis and the brain. The existence of a previously unreported nerve branch of the frontal nerve is described here in the frog Rana esculenta and called the lateral nerve. The course of the lateral nerve and its junction with the frontal nerve have been consistently detected by means of different techniques: toluidine blue staining in semithin sections, the Landau-Ignesti method for myelinated nerve fibers, the methylene blue intravital staining for peripheral nerves, and in vitro tracing with the carbocyanine Dil. A method to preserve intact the delicate lateral nerve during dissection is also described. The lateral nerve was consistently found to be unilateral, and to join the frontal nerve at one end (either on the left or the right side), whereas the other extremity was found to be dispersed in the dermis. Thus, the lateral nerve could represent a new pathway interconnecting the skin and the brain and/or the frontal organ in the frog.

Animals↗

CD4 down-modulation by ganglioside and phorbol ester inhibits human herpesvirus 7 infection.

Recently, data demonstrating that CD4 is an essential component of the receptor for human herpesvirus 7 (HHV-7) as well as for human immunodeficiency virus have been accumulating. Since gangliosides and phorbol esters are known to induce selective down-modulation of cell surface CD4 expression, it might be expected that treatment with these agents would interfere with HHV-7 infection of CD4+ T cells. The present study, undertaken to verify this possibility, demonstrated that addition of monosialoganglioside-GM1 or 12-O-tetradecanoylphorbol 13-acetate effectively induced disappearance of CD4 from the cell surface and also reduced HHV-7 infectivity, as judged by the CPE on virus-infected cells and studies of indirect immunofluorescence, TCID50 and semi-quantitative PCR of the HHV-7 genome. Taken together with previous studies, the present data strongly suggest that the CD4 molecule is a critical component of the receptor for HHV-7.

Antigens, Viral↗

Comparison of the immune response against Mycobacterium tuberculosis antigens between a group of patients with active pulmonary tuberculosis and healthy household contacts.

The mycobacterial antigens and the factors related to protection for the development of active tuberculosis are not known. In a natural model of tuberculosis, we studied 10 patients with active pulmonary tuberculosis (non-protective immune response) and 38 healthy household contacts (protective immune response). We tested the lymphocyte proliferative response by T cell Western blotting to eight different antigen fractions and to two purified mycobacterial antigens of 30 and 64 kD. Patients with active tuberculosis recognized fractions with molecular weights of 80-114, 60-80, 28-41 and 14-19 kD. Household contacts recognized the same fractions except the 14-19 kD. The response to the 64-kD antigen was not significantly different between groups. In contrast, 10% of the patients with active tuberculosis and 73% of the household contacts responded to the 30-kD antigen. The humoral response against the 30-kD antigen by ELISA showed a significantly higher production of antibodies in tuberculosis patients compared with household contacts. We conclude that patients with active pulmonary tuberculosis develop an immune response characterized by poor proliferative response to the 30-kD antigen with a strong humoral response, whereas the opposite occurs in healthy subjects infected by Mycobacterium tuberculosis.

Antibodies, Bacterial↗

Recognition of liposome-bound antigens by antipeptide antibody.

In order to clarify the effects of the differences in physical states of antigens on recognition by antibodies in immunoassays, the binding characteristics of an antipeptide polyclonal antibody to the peptide and the corresponding protein were studied. The reactivity in the immunoliposome assay (ILA), as well as in the double-antibody sandwich ELISA, was identical to that in the solution. These results indicate that the conformation of liposome-bound antigen is changed little by coupling to liposomes and is almost the same as that of the native antigen in the liquid phase. It is desirable to assay by double-antibody sandwich ELISA or ILA to detect native proteins, and the latter is very easily performed.

Animals↗

Pulmonary perfusion during lung transplant rejection and experimental pneumonia.

Six left lung allotransplants were performed in healthy mongrel dogs. Immunosuppression was established with cyclosporine (15 mg/kg/day p.o.) from the day of transplantation for 30 days. Another group of animals (n = 3) was used to produce acute experimental pneumonia by instilling 4-6 ml of a 10(8) CFU suspension of Pseudomonas aeruginosa into the right lower lobe. Dynamic perfusory lung scintigraphy (DPLS) was performed before transplant/pneumonia (control), during acute rejection/pneumonia as detected radiologically, and after treatment with methylprednisolone (1 g/day for 3 days i.v.) (transplant group) or antibiotics (pneumonia group). Seroalbumin macroaggregates (5-8 McI) marked with 99-mTc were injected into the cephalic vein and the percentage of perfusion to each lung was determined. Eight acute rejection episodes were detected. DPLS showed similar perfusion to each lung, whereas during acute rejection perfusion was significantly reduced by almost 30%. Perfusion was reestablished to control levels after treatment with methylprednisolone. Reduction in perfusion correlated with radiological rejection grading. No reduction in left lung perfusion was detected in pneumonia animals. In conclusion, acute rejection reduces perfusion to the transplanted lung as measured by DPLS. Treatment restores normal perfusion.

Animals↗

Detection of lipoarabinomannan as a diagnostic test for tuberculosis.

A coagglutination technique was established for the detection of lipoarabinomannan of Mycobacterium tuberculosis in human serum samples and evaluated for its utility in the diagnosis of tuberculosis at the Instituto Nacional de Enfermedades Respiratorias in Mexico City. The test had a sensitivity of 88% in patients with sputum-smear-positive active pulmonary tuberculosis. The sensitivity in patients with active pulmonary tuberculosis negative for acid-fast bacilli in sputum was 67%. Less favorable results were obtained for patients with AIDS and tuberculosis, with a sensitivity of 57%. The specificity in control patients with lung diseases different from tuberculosis and in healthy subjects was 100%. The positive predictive value was 100%, and the negative predictive value for patients with sputum-positive active pulmonary tuberculosis was 97%. The results of this study suggest that the detection of lipoarabinomannan is an accurate test for the diagnosis of pulmonary tuberculosis.

Acquired Immunodeficiency Syndrome↗

Characterization of Leptospira strains HY-1, HY-2, and HY-10 isolated in Korea by means of monoclonal antibodies and restriction endonuclease DNA analysis.

To analyze the characteristics of Leptospira strains HY-1, HY-2, and HY-10, which were isolated from patients with leptospirosis in Korea in 1985, 12 monoclonal antibodies (MAbs) against strain HY-1 and six MAbs against serovar lai strain 017 were produced, and their properties were determined by the microscopic agglutination test. Genetic relationships among the leptospires were determined by restriction endonuclease DNA analysis. Three MAbs reacted with all strains of serogroup Icterohaemorrhagiae, but did not react with any strains of the other 10 serogroups. All MAbs reacted with strains 017, HY-1, HY-2, and HY-10 at nearly identical titers. Two MAbs reacted only with these four strains. These four strains also had the same restriction endonuclease cleavage patterns. Based on these results, strains HY-1, HY-2, and HY-10 were identified as serovar lai, which is one of the common serovars in China. It is suggested that serovar lai is one of the prevalent serovars in Korea, and that the Mabs produced in this study are useful for the accurate and rapid identification of this serovar.

Agglutination Tests↗

[Eosinophilic leukemia with cyclic eosinophilic leukocytosis].

A 36-year-old male was admitted to the Ehime University Hospital with anemia, eosinophilia and hepatosplenomegaly. Peripheral blood examination demonstrated severe anemia (Hb 7.1g/dl), thrombocytopenia (Plt 6.8 x 10(4)/microliters) and increase of peripheral leukocyte counts (53,000/microliters) with 32.0% of eosinophils which had lobulated nuclei, abnormal distribution of eosinophilic granules and a few vacuoles. The level of serum IgE was low (< 5IU/ml), while that of serum vitamin B12 was elevated. A diagnosis of eosinophilic leukemia was made. He was noted to have spontaneous fluctuations in his eosinophil and total leukocyte counts. To analyze the mechanism of cyclic eosinophilic leukocytosis, we examined eosinophil colony stimulating activity of the serum and plasma of the patient. These examination showed that eosinophil colony-stimulating activity was not found in his serum and plasma, and cyclic eosinophilic leukocytosis was due to the hemopoietic stem cell disorder.

Adult↗

Incorporation and activation of a membrane-bound enzyme in bilayers of liposomes.

The effects of lipid composition and fluidity of lipid bilayers on incorporation and activation of membrane-bound D-fructose dehydrogenase are described in this study. The incorporation of the enzyme into bilayers of small unilamellar vesicles (SUV) made of several phospholipids resulted in enzyme activation with magnitudes higher than that observed in the presence of Triton X-100, indicating that this higher activation is due to lipid-protein interaction. The activity was highest in the presence of SUV formed by the addition of 10% DL-alpha-dipalmitoylphosphatidylethanolamine to L-alpha-dimyristoylphosphatidylcholine, which resulted in eightfold higher activation compared with that of the enzyme in its free state. This activation did not appear to be due to the degree of incorporation of the enzyme, indicating that incorporation is distinct from the activation event. Thus, it is probably the lipid environment that leads to higher activation of the enzyme. A break in the Arrhenius plot of the activity of the membrane-bound enzyme at temperatures close to the phase transition of the phospholipid implies that changes in the physical state of the lipid bilayer influence the enzyme activity. Furthermore, immobilization of D-fructose dehydrogenase, previously adsorbed to SUV, on urethane prepolymer also resulted in about eightfold higher activation than that of the free enzyme.

Carbohydrate Dehydrogenases↗

The significance of serum mitochondrial aspartate aminotransferase activity in the surgical field.

A study was carried out on the clinical significance of changes in the serum level of mitochondrial aspartate aminotransferase before and after surgery on patients suffering from various hepato-biliary diseases. The patients included those whose livers were impaired with cirrhosis, jaundice, or direct surgical intervention such as hepatectomy. It was found that the postoperative liver function of patients whose preoperative values of serum mitochondrial aspartate aminotransferase had been less than 10 Karmen units recovered with a favorable course, whereas that of patients whose values had exceeded 20 units deteriorated with persistent jaundice, ascites or hepatic insufficiency. Both the sensitivity and specificity of respective liver function tests were examined by the preoperative values of routine liver function tests and the postoperative liver functions. The results revealed the serum value of mitochondrial aspartate aminotransferase to be more sensitive than the other tests, while specificity was not significantly different. A safety limit for a favorable postoperative course in terms of liver function was observed in patients showing a preoperative serum mitochondrial aspartate aminotransferase activity of below 10 units. Thus, serum mitochondrial aspartate aminotransferase activity could be applied as a useful marker for hepato-biliary surgery.

Adolescent↗

Serological studies on Leptospira strain Ictero No. I using monoclonal antibodies.

In order to elucidate the full serological characteristics of strain Ictero No. I, the first strain of Leptospira isolated by Inada and Ido in 1914, 17 monoclonal antibodies against the strain were produced by cell fusion technology. The antibody-producing hybridomas were designated IMAs 1 to 17. The reactivities of the monoclonal antibodies produced by the hybridomas were determined by the microscopic agglutination test. One of the 17 monoclonal antibodies, IMA 1, reacted with strains Ictero No. I, LT 1131 and Naam, but not with other strains of the serogroup Icterohaemorrhagiae including strain RGA used in the present study. Moreover, the reactivity of the antigenic determinant of IMA 1 was inactivated by treatment at 56 C for 30 min. The 16 other monoclonal antibodies, IMAs 2 to 17, showed different reaction patterns against Leptospira strains of the serogroup Icterohaemorrhagiae. All of the 16 antibodies reacted with both Ictero No. I and RGA strains. The antigens against antibodies IMAs 2 to 17 were thermostable. The present study thus clarified the presence of a thermolabile antigen in strain Ictero No. I, and allowed correct distinction between the serotype of strain Ictero No. I and that of strain RGA using IMA 1. Therefore, we propose that strain Ictero No. I represents serovar icterohaemorrhagiae, as originally designated by Inada and Ido. Moreover, strain Ictero No. I should be designated as the type strain of Leptospira interrogans.

Agglutination↗

Effects of histidine residues on adsorption equilibrium of peptide antibodies.

Histidine and arginine residues in a peptide, which represent residues 112-121 of myoglobin, were replaced by alanine, and antibodies for these peptides were raised in rabbits. Adsorption equilibria between these peptides and antibodies were measured to identify the essential amino acid residues for specific binding and their effects on adsorption behavior. Protonation of one histidine residue affected strongly the dependence of adsorption equilibrium on pH, and the adsorption capacities of the antibodies against the peptides containing this essential histidine residue rapidly decreased at around pH 5-6, which corresponds to the pKa value of histidine. Immunization with peptide sequences containing such histidine residues is one method to obtain suitable antibodies for immunoaffinity chromatography, which have a weak affinity for the elution step under mild conditions.

Adsorption↗

Effects of surface charges and cholesterol content on amino acid permeabilities of small unilamellar vesicles.

The permeabilities of amino acids through bilayer lipid membranes were determined using small unilamellar vesicles (SUV). Alanine, lysine, arginine, and glutamate show permeabilities on the order of 10(-10)-10(-11) cm/s in the case of SUV prepared from dimyristoylphosphatidylcholine and dicetylphosphate. An increase in the amount of negative charges introduced by dicetylphosphate enhanced the permeability of the positively charged amino acid (i.e., lysine). The permeabilities of net charged amino acids decreased with an increase in cholesterol content, and became less than 10(-12) cm/s with the membrane which consists of equimolar amounts of dimyristoylphosphatidylcholine and cholesterol.

Alanine↗

The significance of serum mitochondrial aspartate aminotransferase activity in obstructive jaundice: experimental and clinical studies.

The serum level of mitochondrial aspartate aminotransferase was determined in experimental and clinical obstructive jaundice, using an immunoabsorbance method which allowed the differential determination of cytosolic and mitochondrial isozymes in the serum. In experimental obstructive jaundice using dogs, the serum mitochondrial aspartate aminotransferase value rapidly decreased to normal after biliary decompression following a period of biliary obstruction of within 3 weeks. On the other hand, when the period of jaundice was prolonged for 5 weeks, the activity of the enzyme after biliary drainage still continued to show high values, being 14.2 +/- 1.8 Karmen units at 4 weeks following biliary decompression. Determination of aspartate aminotransferase activity in tissue from such organs as the liver, heart, kidney, skeletal muscle and brain, as well as serum samples withdrawn from local veins, confirmed that high serum values of the enzyme in experimental obstructive jaundice were mostly attributable to hepatic impairment induced by biliary obstruction not by secondarily damaged tissues of other organs. Mitochondrial aspartate aminotransferase proved to be a more useful marker than other routine tests in icteric dogs. In 13 clinical patients with obstructive jaundice, decreasing rates of serum mitochondrial aspartate aminotransferase on the 7th and 14th postoperative days could be applied to evaluate the viability of the icteric liver. The decreasing rates were more advantageous than the preoperative activity itself in predicting the postoperative function of the liver. Thus, mitochondrial aspartate aminotransferase appears to serve as a useful marker for assessing the liver function in obstructive jaundice.

Adolescent↗

An ELISA for the serodiagnosis of tuberculosis using a 30,000-Da native antigen of Mycobacterium tuberculosis.

An ELISA was established for the measurement of IgG antibody in human serum to the 30,000-Da native antigen of Mycobacterium tuberculosis and evaluated for its utility in the diagnosis of tuberculosis at the Instituto Nacional de Enfermedades Respiratorias in Mexico City. The test had a sensitivity of 70% in patients with sputum-positive active pulmonary tuberculosis and a specificity in control subjects of 100%. The accuracy of positive prediction was 100% and of negative prediction 93% for patients with pulmonary tuberculosis at this institute. Less favorable test characteristics were obtained for patients with miliary and pleural tuberculosis, in which the test had sensitivities of 22% and 14%. These results offer the promise of an accurate serodiagnostic test for pulmonary tuberculosis using readily obtained reagents.

Antibodies, Bacterial↗