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Biomedical subjects

S Harada

Publications and source records attributed to S Harada.

At least 595 records · Page 33Linked to original sources
PubMed1984

A new crystal form and preliminary crystallographic data for ferricytochrome c' from Rhodospirillum rubrum.

A new crystal form of ferricytochrome c' from the photosynthetic bacteria, Rhodospirillum rubrum, has been obtained by dialysing protein solution against polyethylene glycol 4000. The crystals belong to the space group P61 (or its enantiomorph P65) with unit cell dimensions: a = b = 51.63 A and c = 155.39 A. The asymmetric unit contains one dimer molecule of 28,000 molecular weight and the solvent content of the unit cell is approximately 38%.

Crystallization↗
PubMed1984

Genetic analysis of human lymphocyte proteins by two-dimensional gel electrophoresis: VI. Identification of esterase D in the two-dimensional gel electrophoresis pattern of cellular proteins.

C33k polypeptide, which is a cytosol polypeptide with molecular weight of 33 000 and approximate pI value of 7.5, has three common electrophoretic phenotypes and is an abundant polypeptide in peripheral blood lymphocytes, fibroblasts and red blood cells. Family and population studies indicate that the three phenotypes of C33k polypeptide are determined by two common alleles at a single autosomal locus. The gene frequencies of the two common alleles were 0.642 and 0.358, respectively, in a Japanese population. Since esterase D has a subunit size and gene frequencies similar to those of C33k polypeptide, the phenotypes of C33k polypeptide and esterase D were compared in 18 families totaling 72 members. Perfect concordance of the phenotypes between C33k polypeptide and esterase D was observed in all 72 members. In addition, a gene dosage effect on the expression of the phenotype of C33k polypeptide was observed in the red blood cell lysate from a patient with partial 13q trisomy who was reported to have two doses of EsD1 and one dose of EsD2. These data indicate that the polymorphic C33k polypeptide is esterase D, which is assigned to chromosome 13q14. This finding is useful for the detection of proteins coding for by chromosome 13q14-linked genes in the studies on human gene mapping using somatic hybrid cell lines and two-D gel electrophoresis.

Blood Proteins↗
PubMed1984

A rare case of early carcinoma of the gallbladder.

A 38-year-old woman was diagnosed preoperatively to have a benign polyp of the gallbladder with a delineated polypoid mass, as demonstrated with drip infusion cholangiography and ultrasonography. Cholecystectomy was performed. Postoperatively, however, this tumor proved to be an early stage carcinoma of the gallbladder. In the neck of the gallbladder, there was a protruded polypoid elastic tumor of 1.1 X 0.9 cm in width and 2.5 cm in height. The tumor was supported by a stem of 0.1 cm in diameter and 0.2 cm in height. Histopathological examination revealed a well differentiated papillotubular adenocarcinoma, which exhibited no invasion of the stem itself or its basal region. This is a rare case of early carcinoma of the gallbladder (Stage I) which grew only towards the lumen of the gallbladder cavity, and did not invade the wall. Postoperatively, cholecystectomy alone was thought to be sufficient for cure.

Adenocarcinoma↗
PubMed1984

Chronic mononucleosis syndrome.

We present data on 14 patients with chronic symptoms of disabling fatigue in association with serologic evidence of active Epstein-Barr virus (EBV) infection. Two thirds were women, and the average age at onset was 29.6 years. Forty-three percent were known to have had previous infectious mononucleosis, but the usual criteria for that diagnosis were not helpful with the present syndrome. Eighty-six percent had serologic evidence of cytomegalovirus (CMV) infection. Profound immunodeficiency was not present, but 71% had partial hypogammaglobulinemia, and minor abnormalities of T cell subsets were noted in six of seven patients studied. Fifty-seven percent achieved temporary serologic and symptomatic remission after an average duration of 33 months. Only one patient has a sustained remission. Comparison is made with other reported chronic, recurrent, and persistent EBV syndromes, and tentative diagnostic criteria for chronic mononucleosis syndrome are presented. Recently available EBV serologic techniques allow for identification of patients who have reactivated EBV infection, and this reactivation may be related to symptoms.

Adolescent↗
PubMed1984

Similar effects of various low-molecular-weight enzyme inhibitors on enzyme networks in dystrophic mice.

We compared the therapeutic effects of various low-molecular-weight enzyme inhibitors on dystrophic mice. Leupeptin, bestatin, forphenicinol and forphenicine significantly affected the enzymatic activities in the dystrophic muscles. The pattern of enzymatic changes in the muscles of forelimb and hindlimb caused by these inhibitors were similar in spite of the variety of their inhibitory spectra in vitro. However, comparing the pattern of enzymatic changes in spleen, forphenicinol differed from the other inhibitors tested. This may be related to the peculiar effects of this inhibitor on immunologically responsive cells.

Alkaline Phosphatase↗
PubMed1984

Cephabacins, new cephem antibiotics of bacterial origin. II. Isolation and characterization.

Fifteen components of new antibiotics, cephabacins, were isolated from the culture filtrates of Lysobacter lactamgenus YK-90, Xanthomonas lactamgena YK-280 and X. lactamgena YK-278. They were purified by column chromatography using cation-exchange resins, activated carbon, high porous resins and cation-exchange Sephadex and by preparative reverse-phase HPLC. The basic, water-soluble antibiotics were characterized as having a cephem skeleton and oligopeptide(s) as a side chain constituent from their spectroscopic analyses and amino acid analyses.

Cephalosporins↗
PubMed1984

Cephabacins, new cephem antibiotics of bacterial origin. III. Structural determination.

The structures of 15 new cephem antibiotics, cephabacin F1-9 and H1-6, were determined by their spectroscopic analyses and decomposition studies. They are consisted of a cephalosporin nucleus and a di, tri or tetrapeptide including a new amino acid which is bound at the position 3 with an ester bond. The components, F1-9, showed unique biological activities by the presence of a formylamino group at the position 7.

Cephalosporins↗
PubMed1984

Cephabacins, new cephem antibiotics of bacterial origin. IV. Antibacterial activities, stability to beta-lactamases and mode of action.

Cephabacin F group antibiotics with a 7-formylamino substituent showed antibacterial activity against a wide variety of bacteria including beta-lactamase-producing clinical isolates and anaerobic bacteria. Cephabacin H group antibiotics without the substituent showed more potent activity against Gram-positive bacteria than cephabacin F group antibiotics, but were not active against Gram-negative bacteria producing beta-lactamases. Cephabacin F group antibiotics were highly resistant to hydrolysis by various types of beta-lactamases and showed strong inhibitory activity against a cephalosporinase of Proteus vulgalis GN 4413 due to the 7-formylamino substituent. Mode of action of cephabacin F1 and H1 was examined using Escherichia coli and Bacillus subtilis as the test organisms. They showed strong lytic activity against these organisms and inhibited their peptidoglycan synthesis. Cephabacin F1 had the highest affinity for penicillin-binding protein (PBP) 1 in E. coli and PBP 4 in B. subtilis. Cephabacins showed a protective effect in experimentally infected mice.

Bacteria↗
PubMed1984

Structure-activity relations of 5,6-cis carbapenem antibiotics and role of factors determining susceptibility of Escherichia coli to beta-lactam antibiotics.

The antibacterial activities of twelve 5,6-cis carbapenem antibiotics, including four semisynthetic derivatives of C-19393 H2 and S2, against 15 microorganisms were examined, and their structure-activity relations are discussed in relation to minimum inhibitory concentrations against Staphylococcus aureus and Escherichia coli as a Gram-positive and a Gram-negative standard strain, respectively. The contribution of chromosomal beta-lactamase (amp C), permeability barrier, and penicillin-binding protein (PBP) 1B to the resistance of E. coli to these carbapenem antibiotics was examined using mutants lacking each of these cellular components. The beta-lactamase was not involved in the resistance. These antibiotics easily permeated the outer membrane. A PBP 1B-defective mutant was supersensitive to these carbapenem antibiotics and to other types of beta-lactam antibiotics.

Anti-Bacterial Agents↗
PubMed1984

Delayed onset of infectious mononucleosis associated with acquired agammaglobulinemia and red cell aplasia.

In 1974, an 11-year-old white boy with the X-linked lymphoproliferative syndrome developed hyper-IgM after becoming infected with Epstein-Barr virus. However, he failed to develop normal immune responses against the virus. In December 1981, when red cell aplasia occurred, he was given packed erythrocytes and gammaglobulin. Nine weeks later, acute infectious mononucleosis developed. Concurrently, his T4/T8 helper/suppressor ratio decreased from 2.7 to 0.2, and IgM antibodies to Epstein-Barr virus appeared. Subsequently, circulating B cells became undetectable in his blood, and agammaglobulinemia appeared. Red cell aplasia abated transiently. This patient's course was complicated by Haemophilus influenzae and Mycobacterium tuberculosis pneumonias, and red cell aplasia and agammaglobulinemia have persisted. Epstein-Barr virus acting as a slow virus probably induced the red cell aplasia and agammaglobulinemia because of the aberrant immune responses to Epstein-Barr virus. Immunodeficient responses to Epstein-Barr virus should be sought in other patients with the diseases documented in our patient.

Agammaglobulinemia↗
PubMed1984

[Penetration of cefmenoxime into pleural fluid].

Single doses of cefmenoxime (CMX), 1 g intravenous drip infusion, were administrated to 5 patients with pleural effusion. The study group consisted of 3 men and 2 women, aged 38 to 69 years (mean 54.8 years); 4 had carcinoma with pleural effusion and 1 had SLE. Pleural fluid and serum samples were taken at intervals 1 to 24 hours for determination of CMX levels. The following results were obtained: Intravenous drip infusion of 1 g CMX yielded a peak pleural concentration of 4.5 micrograms/ml after 2 hours and pleural levels over 3 micrograms/ml were maintained for 5.5 hours after intravenous drip administration. Ratio maximum pleural concentration to peak serum level reached 15.0 +/- 8.3% at 2 hours after intravenous drip administration.

Adult↗
PubMed1984

Squamous-cell carcinoma, Kaposi's sarcoma and Burkitt's lymphoma are consequences of impaired immune surveillance of ubiquitous viruses in acquired immune deficiency syndrome, allograft recipients and tropical African patients.

The immune system has evolved under Darwinian pressures as a defence against ubiquitous viruses. Immune surveillance against viral antigens protects the normal host. Individuals with inherited or acquired immune-deficiency disorders can become vulnerable to ubiquitous viruses and neoplasms can ensue, such as B-cell lymphoma, hepatocellular carcinoma, squamous-cell carcinoma, Kaposi's sarcoma, and carcinoma of the penis and uterine cervix. Immunodeficiency permits Epstein-Barr virus, hepatitis B virus, papillomavirus, herpes simplex virus, and cytomegalovirus to induce sustained target-cell proliferation. Each virus selects specific cellular targets bearing viral receptors and the infection leads to proliferation of the target cells rather than lysis. Various co-factors, including nutrition, exposure to tumour-promoting agents, parasitic infection, and ultraviolet light, may promote carcinogenesis. Depending on the type and severity of the immune deficiency, gradual proliferation may lead to evolution of a malignant clone. Conversion of polyclonal virally infected proliferating cells to give monoclonal malignancy is probably due to specific cytogenetic rearrangements which allow oncogene activation and endow an altered tumour cell with selective growth advantages over normal diploid cells. Prevention of viral oncogenesis may be possible by treatment of immune-deficient individuals with premalignant disorders. Immunotherapy and antiviral therapy may prevent progression of viral-induced proliferation to malignancy. The purpose of this paper is to discuss and evaluate the role of immune deficiency and viruses in the induction of malignancies commonly occurring in Africans residing in sub-Saharan Africa (Purtilo, 1976). The types of malignancies commonly occurring in this region are believed to be due to ubiquitous viruses. A failure of immune surveillance mechanisms to recognize viral antigens and abrogate proliferation of infected target cells predisposes to malignancy by increasing the chance of a proliferating cell undergoing a cytogenetic or molecular alteration which endows it with malignant characteristics. The immunological surveillance hypothesis has been elaborated during this century by Ehrlich, Thomas, Burnet, and Schwartz (reviewed by Purtilo & Linder, 1983). This hypothesis rests on several assumptions: that neoplastic cells possess unique tumour antigens: tumour antigens provoke an immune response in the host; and the immune response is protective and eliminates the tumour.(ABSTRACT TRUNCATED AT 400 WORDS)

Acquired Immunodeficiency Syndrome↗