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Biomedical subjects

Y Hirota

Publications and source records attributed to Y Hirota.

At least 433 records · Page 24Linked to original sources
PubMed1984

[Immunohistochemical demonstration of carcinoembryonic antigen and ultrastructural features of endometrial adenocarcinoma].

Determination of carcinoembryonic antigen levels in plasma (45 cases) and the immunohistochemical demonstration of tumor CEA (37 cases) were carried out in patients with endometrial adenocarcinoma. Twenty four out of 37 were also studied with the electron microscope. The plasma CEA level prior to therapy was significantly elevated (greater than 5.0ng/ml) in only one case (1/45:2.2%) of endometrial adenocarcinoma. CEA levels were more consistently elevated (4/17:23.5%) in patients with cervical adenocarcinoma. Immunoperoxidase staining of CEA (PAP method) was carried out using formalin-fixed paraffin embedded sections of 37 tumors. Tissue CEA activities were found in 9 out of 37 endometrial adenocarcinomas (24.3%) and 19 of 23 cervical adenocarcinomas (82.6%). Immunoreactive CEA was present in a high concentration on the cell surface of endometrial glands and less dense in their cytoplasm. In 9 of CEA positive endometrial carcinoma tissues, squamous metaplastic lesions were found in 4 cases and mucinous metaplasia in one case which were all CEA positive. With regard to the histopathological grade, CEA positive specimens were categorized G1 (4) and G2 (5) and all of the G3 were CEA negative. Seven of 9 cases of CEA positive specimens were examined under the electron microscope. There was no definite tendency in their ultrastructural characteristics, but all of the specimens examined revealed abundant cytoplasmic organelles suggestive of intracytoplasmic differentiation analogous to those of endometrial cells in proliferative phase. Moreover, fine structures of squamous and mucinous metaplastic cells were also described in detail.

Adenocarcinoma↗
PubMed1984

Multicenter studies of 2% nitroglycerin ointment in patients with heart failure.

Nitroglycerin ointment (NTGO) was applied to the precordial area in 88 patients with heart failure arising from acute myocardial infarction (AMI) or other types of heart disease, and its effects on hemodynamic parameters were determined. After NTGO was applied, patients' systolic blood pressure (P less than 0.001), double product (heart rate X systolic pressure, P less than 0.001), pulmonary capillary wedge pressure (P less than 0.001), and systemic vascular resistance (P less than 0.001) decreased significantly. These changes began 30 to 60 minutes after NTGO was applied and lasted two to six hours. Based on these hemodynamic changes, we conclude that NTGO is beneficial for patients with heart failure due to AMI or other heart disease.

Administration, Topical↗
PubMed1983

N-acetylmuramoyl-L-alanine amidase of Escherichia coli K12. Possible physiological functions.

Various experiments were carried out in an attempt to determine the possible physiological function of the N-acetylmuramoyl-L-alanine amidase purified from Escherichia coli K12 on the basis of its activity on N-acetylmuramoyl-L-alanyl-D-gamma-glutamyl-meso-diaminopimelic acid [MurNAc-LAla-DGlu(msA2pm)]. A Km value of 0.04 mM was determined with this substrate. Specificity studies revealed that compounds with a MurNAc-LAla linkage are the most probable substrates of this enzyme in vivo. Purified amidase had no effect on purified peptidoglycan and only low levels (1-2.5%) of cleaved MurNAc-LAla linkages were detected in peptidoglycan isolated from normally growing cells. However, the action of the amidase in vivo on peptidoglycan was clearly detectable during autolysis. The amidase activity of cells treated by osmotic shock, ether or toluene, as well as that of mutants with altered outer membrane composition was investigated. Attempts to reveal a transfer reaction catalysed by amidase were unsuccessful. Furthermore, by its location and specificity, amidase was clearly not involved in the formation of UDP-MurNAc. The possibility that it might be functioning in vivo as a hydrolase degrading exogeneous peptidoglycan fragments in the periplasma was substantiated by the fact that MurNAc itself and MurNAc-peptides could sustain growth of E. coli as sole carbon and nitrogen sources. Finally, out of 200 thermosensitive mutants examined for altered amidase activity, only two strains had less than 50% of the normal level of activity, whereas ten strains were found to possess more than 50%. In fact, two of the overproducers encountered presented a 4-5-fold increase in activity.

Amidohydrolases↗
PubMed1983

The 245 base-pair oriC sequence of the E. coli chromosome directs bidirectional replication at an adjacent region.

The replication origin of the E. coli K-12 chromosome has been isolated as autonomously replicating molecules(oriC plasmid), and the DNA region essential for replicating function(oriC) has been localized to a sequence of 232-245 base-pairs(bp) by deletion analysis. In this report, the functional role of oriC was analysed by using an in vitro replication system and various OriC+ and OriC- plasmids previously constructed. The results obtained were summarized as follows: (1) The oriC sequence contained information enough to direct bidirectional replication. (2) The actual DNA replication began at a region near, but outside, oriC and progressed bidirectionally. (3) Initiation of DNA synthesis at the specific region required the dnaA-complementing fraction from cells harboring a dnaA-carrying plasmid.

Base Sequence↗
PubMed1983

Cardiovascular effects of a newly synthesized cardiotonic agent (TA-064) on normal and diseased hearts.

A new inotropic agent, TA-064, (-)-alpha-(3,4-dimethoxyphenethylaminomethyl)-4-hydroxybenzylalcohol, was shown to have strong effects in experimental animals. Its effectiveness and associated adverse effects were tested in humans invasively (n = 6) and noninvasively (n = 17). Increasing doses of intravenous infusion (1, 2, and 4 micrograms/kg/min) increased plasma levels to 15, 35, and 82 ng/ml, respectively, resulting in marked increases in the peak rate of left ventricular pressure rise (dP/dt) (1,450 +/- 63 to 3,042 +/- 349 mm Hg/s) (mean +/- standard error of the mean [SEM], p less than 0.01) and the ratio of dP/dt to left ventricular pressure at a developed pressure of 40 mm Hg (25 +/- 3 to 39 +/- 2 s-1) (p less than 0.01), with a reduction in left ventricular end-diastolic pressure (12 +/- 2 to 4 +/- 1 mm Hg) (p less than 0.01). Minimal or no changes were seen in heart rate and left ventricular systolic pressure. After a single oral dose (10 mg), the plasma level reached its peak at 90 minutes (16 +/- 9 ng/ml, n = 17). A positive inotropic effect was confirmed echocardiographically in both healthy volunteers (n = 8) and patients with congestive heart failure (CHF) (n = 9) who were maximally treated with conventional regimens: increase in mean velocity of circumferential fiber shortening (healthy volunteers: 1.29 +/- 0.05 to 1.60 +/- 0.11 circ/s [p less than 0.05]; patients with CHF: 0.69 +/- 0.08 to 0.93 +/- 0.09 circ/s [p less than 0.01]), ejection fraction (healthy volunteers: 68 +/- 2 to 75 +/- 2% [p less than 0.05], patients with CHF: 37 +/- 4 to 45 +/- 5% [p less than 0.01]) without change in heart rate. The cardiac index was increased only in the CHF group (2.71 +/- 0.22 to 3.21 +/- 0.24 liters/min/m2) (p less than 0.05). No significant untoward effects were observed. Thus TA-064 is a potent inotropic agent and can be used either parenterally or orally. Salutary effects can be expected in patients with congestive heart failure who are treated with digitalis and diuretic agents.

Adult↗
PubMed1983

Mutants of Escherichia coli defective in penicillin-insensitive murein DD-endopeptidase.

Two mutants of Escherichia coli that are deficient in the penicillin-insensitive DD-endopeptidase have been isolated. The strain JE10874 (mepA) has about 10%-20% of the residual activity and another strain, JE10368 (mepB) has 40%-50% of the activity found in the wild-type, parental strain, PA3092. The penicillin-insensitive endopeptidase is a periplasmic enzyme. Genetic mapping studies show that the mutation mepA is located close to aroC (50 min) and the other mutation, mepB, is very close to malE (91 min) on the chromosome. These mutants grow normally under a wide range of growth conditions; other phenotypic properties of the mutants are very similar to those of the parent strain. A double mutant (mepA mepB), and a triple mutant (mepA mepB dacB), deficient in both penicillin-insensitive and penicillin-sensitive endopeptidases, were constructed. Again, these mutants grew normally. We conclude that either the very low level of residual enzyme activity in the mutants is enough for their survival or that the penicillin-insensitive endopeptidase is not essential for survival under laboratory conditions.

Chromosome Mapping↗
PubMed1983

Escherichia coli uvrD mutants with thermosensitive DNA-dependent adenosine triphosphatase I (helicase II).

Three mutants producing thermosensitive DNA-dependent Adenosine triphosphatase (ATPase) I were screened from a collection of temperature-sensitive mutants of Escherichia coli K12. ATPase I purified to near homogeneity from one of the mutants (JE11000) possesses both thermosensitive DNA-dependent ATPase and DNA helicase activities. We have shown that ATPase I is encoded by the uvrD gene as first suggested by Oeda et al. (1982): (i) the thermosensitive ATPase I mutation present in JE11040 lies in or very close to the uvrD gene, (ii) ATPase I activity is absent in uvrD210, uvrD156, and uvrD252 mutants. Thus the thermosensitive mutations correspond to new uvrD mutations. However, the mutation present in JE11040 confers neither UV sensitivity nor mutator phenotype at high temperature. Evidence is presented that the mutant ATPase I is stabilized in vivo at 42 degrees C.

Adenosine Triphosphatases↗
PubMed1983

Excess mortality and morbidity associated with right bundle branch and left anterior fascicular block.

Excess mortality and morbidity associated with right bundle branch and left anterior fascicular block were evaluated in 108 patients with block (age 74 +/- 10 years, 69% male) and 108 age- and sex-matched control patients with normal conduction. Clinical characteristics were similar initially except for more congestive heart failure in patients with block. Life table analysis revealed a higher 12 year mortality with block, even after omitting patients with moderate or severe congestive heart failure (risk ratio 1.47, p less than 0.05). Compared with control subjects, the group of patients with block had more sudden death and deaths of unknown cause, but a similar number of noncardiac and diagnosed cardiac deaths. More patients with block developed new second and third degree atrioventricular block or new overt coronary artery disease, but this finding did not support prophylactic pacing in asymptomatic patients. The importance of internal controls in assessing the natural history of clinical and electrocardiographic abnormalities is emphasized.

Adult↗