Effect of cysteine desulfhydrase gene disruption on L-cysteine overproduction in Escherichia coli.

In Escherichia coli, the enzyme called cysteine desulfhydrase (CD), which is responsible for L-cysteine degradation, was investigated by native-PAGE and CD activity staining of crude cell extracts. Analyses with gene-disrupted mutants showed that CD activity resulted from two enzymes: tryptophanase (TNase) encoded by tnaA and cystathionine beta-lyase (CBL) encoded by metC. It was also found that TNase synthesis was induced by the presence of L-cysteine. The tnaA and metC mutants transformed with the plasmid containing the gene for feedback-insensitive serine acetyltransferase exhibited higher L-cysteine productivity than the wild-type strain carrying the same plasmid. These results indicated that TNase and CBL did act on L-cysteine degradation in E. coli cells.

Overproduction of L-cysteine and L-cystine by expression of genes for feedback inhibition-insensitive serine acetyltransferase from Arabidopsis thaliana in Escherichia coli.

Two cDNAs encoding feedback inhibition-insensitive serine acetyltransferases of Arabidopsis thaliana were expressed in the chromosomal serine acetyltransferase-deficient and L-cysteine non-utilizing Escherichia coli strain JM39-8. The transformants produced 1600 to 1700 mg l(-1) of L-cysteine and L-cystine from glucose. The amount of these amino acids produced per cell was 30 to 60% higher than that of an E. coli strain carrying mutant serine acetyltransferase less sensitive to feedback inhibition.

Detection of abnormal high-frequency components in the QRS complex by the wavelet transform in patients with idiopathic dilated cardiomyopathy.

In order to investigate whether increased fine, fractionated signals within the QRS complex can detect arrhythmogenic substrates and how these fine signals link with ventricular mechanical dysfunction, wavelet analysis was performed on averaged QRS complexes obtained from the left precordial lead in 26 patients with idiopatic dilated cardiomyopathy (IDCM) and in 12 normal subjects. The number of local maxima and the duration of the wavelet transform were significantly greater in patients with IDCM than in normal subjects; the number at 100 Hz was 8.8+/-3.1 vs 6.0+/-1.1 (p<0.01), and the duration at 100Hz was 93+/-15 vs 75+/-7ms (p<0.01). Both of these indices were greater in the patients with than in those without late potentials, repetitive ventricular premature beats or cardiac death. In addition, significant inverse curvilinear relationships were observed between the left ventricular ejection fraction and both the number of local maxima and the duration of the wavelet transform. In conclusion, fine fragmented signals in the QRS complex detected by wavelet analysis would be an important marker for potentially arrhythmogenic substrates and seemed to progress in parallel with left ventricular mechanical dysfunction in IDCM.

[Two cases of CA19-9 producing pulmonary papillary adenocarcinoma].

Two cases of CA 19-9 producing pulmonary papillary adenocarcinoma were reported. Pathological examination showed a well differentiated papillary adenocarcinoma with partially bronchiolo-alveolar cell type. Immunohistochemical study showed a positive straining for CA 19-9 on tumor cells. The level of CA 19-9 decreased after lobectomy and anti-cancer chemotherapy using CDDP and VDS. The series of CA 19-9 level is very useful to evaluate the effect of surgery and chemotherapy. Also it is useful to find out the recurrence of carcinoma.

[Assessment of myocardial viability by resting 201Tl SPECT image].

The aim of this study was to assess whether resting 201Tl scintigraphy is superior in detecting viable myocardium than previous conventional methods. We performed not only stress 201Tl SPECT but also resting 201Tl SPECT within one month in 65 patients with coronary artery disease. Resting 201Tl images were quantitatively compared with 4 hour late images of stress study using a polar map. In stress study, redistribution was recognized on 83% (25/30) of non-MI SEGs with perfusion defect in the stress 201Tl image, and on 39% (18/46) of infarcted SEGs. The agreement of resting 201Tl study with 4 hour late images of stress study was shown on 93% (28/30) of non-MI SEGs and on 52% (24/46) of MI SEGs. The increased uptake of 201Tl in resting study, however, was found on 13 (46%) of 28 MI SEGs showing fixed defects in stress study. In stress delayed image with fixed defect, the %Tl uptake of improved SEGs was higher than that of unchanged SEGs (59 +/- 10% vs 48 +/- 11%; p greater than 0.05). There was no viable myocardium which had %Tl uptake less than 40% at stress delayed image. In conclusion, the resting 201Tl imaging will give an important information as for the myocardial viability showing fixed defects, if more than 40% Tl uptake is observed.

[Observation of magnetic fields from three directions, and the moving image of the heart in a normal subject].

Three components of the magnetic field generated by the heart over the anterior aspect of the chest in a normal subject were detected using a Superconducting Quantum Interference Device (SQUID) magnetometer with a single detecting coil in a magnetically shielded room. Contour maps and color density maps of the field were prepared by computer. Movies of sequential magnetic fields of the vertical component on the anterior aspect of the chest were made from these maps. In the movies, the maximum moved from the upper central portion to right lower portion in the early stage of ventricular excitation. It moved to the central portion in the middle stage, then returned to the upper central portion in the late stage. Three-dimensional maps of instantaneous magnetic fields over the anterior portion of the chest were derived from maps of three components of the field, and from presumed heart vectors and were drawn as arrows, based on the Viot-Savart theorem. Heart vectors from these field maps corresponded well with septal forces in the early stage, left ventricular free wall force in the middle stage and the basal force in the late stage, respectively. However, large circulating vectors in the form of clockwise rotation in the central portion were also presumed. These circulating heart vectors did not correspond with the sequence of cardiac excitation as reported by Durrer et al. This discrepancy may have been caused by the fact that the vertical electric current could not be expressed from our display for presuming an electric force. Therefore, new displays and interpretations may be required for the expression of heart vectors.

[Hypereosinophilic syndrome associated with extensive asynergy of the left ventricular wall: a case report].

This is a report of a case of the hypereosinophilic syndrome associated with extensive asynergy of the left ventricular wall. This 41-year-old man's hospital admission in March, 1982 was for congestive heart failure, with marked eosinophilia (34%). Slight depression of the ST segments and flatness of the T waves were observed in electrocardiographic leads I, II, III, a VF, and V 5-6. Digitalis and diuretics were ineffective, but supplementary prednisone therapy resulted in a decrease in eosinophilia and improvement of congestive heart failure. He was transferred to our hospital for further examination in May, 1982. There were no signs of congestive heart failure, but a third heart sound was detected on admission. Marked ST segment depression and inverted T waves were observed in the left precordial leads. Echocardiography cardiography showed extensive asynergy of the left ventricular wall, and progressive enlargement of the left atrium and left ventricle. High density area near the apex of the left ventricle suggested the presence of mural thrombi. A left endocardial biopsy showed organized thrombi sparsely invaded by eosinophils. There were no signs nor symptoms of peripheral emboli. Tapering of the dose of prednisone was attempted twice, but each time eosinophilia resulted. The patient is now free of symptoms, and is being maintained on 25 mg of prednisone daily.

An approach to clinical magnetocardiology.

Magnetocardiograms (MCGs) of normal human subjects and patients with various heart diseases and of fetuses (fetal magnetocardiogram, FMCG) were recorded using a SQUID magnetometer with a built-in second derivative gradiometer in a magnetically unshielded environment. MCGs and ECGs in this study were taken simultaneously at the same precordial chest positions (V1 approximately V6). The following results were obtained: (1) The waves of MCG showed a variety of changes which can never be detected in ECGs. (2) Clear FMCGs could be recorded without being overlapped by MCG of the mother. (3) In MCGs from a patient with complete A-V block, there was a secondary pacemaker spike which was presumably related to ventricular depolarization. (4) There were two kinds of characteristic changes with time in MCGs after onset of anterior myocardial infarction, which could be confirmed in experiments with dogs. Thus, the results obtained so far indicate a bright future of magnetocardiology in clinical medicine.

Quantitative estimation of the right ventricular overloading by thallium-201 myocardial scintigraphy.

Thallium-201 myocardial scintigraphy was performed on 55 patients with various types of right ventricular overloading. The right ventricular (RV) free wall was visualized in 39 out of the 55 patients (71%). The mean values of right ventricular systolic pressure (RVSP) and pulmonary artery mean pressure (PAMP) in the visualized cases (uptakers) were 54.6 +/- 24.1 and 30.5 +/- 15.3 mmHg, respectively. These values were significantly higher than those of the non-visualized cases (non-uptakers). There were 12 RVSP-"normotensive" uptakers and 15 PAMP-"normotensive" uptakers. The RV free wall images were classified into three types according to their morphological features. Type I was predominantly seen in cases of RV pressure overloading, type II in RV volume overloading and type III in combined ventricular overloading. RVSP in the type III group was significantly higher than that in other two groups. The radioactivity ratio in RV free well and interventricular septum (IVS), the RV/IVS uptake ratio was calculated using left anterior oblique (LAO) view images. The RV/IVS uptake ratio closely correlated with RVSP and PAMP (r = 0.88 and 0.82, respectively). In each group of RV free wall image, there were also close correlations between the RV/IVS uptake ratio and both RVSP and PAMP. Our results indicate that the RV/IVS uptake ratio can be used as a parameter for the semi-quantitative estimation of right ventricular overloading.