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Biomedical subjects

D Lang

Publications and source records attributed to D Lang.

At least 181 records · Page 10Linked to original sources
PubMed1985

Cor triatriatum masked by primary pulmonary hypertension.

In a 17-month-old boy with clinical signs of right heart failure, the diagnosis of primary pulmonary hypertension was made, based on cardiac catheterization findings with high pulmonary arterial pressure and normal pulmonary wedge pressure although two-dimensional echocardiography demonstrated a left atrial membrane. Postmortem examination confirmed a left atrial membrane (cor triatriatum), and the microscopic examination revealed the histological pattern of primary pulmonary hypertension. Due to reduced pulmonary blood flow, pulmonary venous obstruction was masked and could not be assessed by measuring pulmonary wedge pressure.

Diagnosis, Differential↗
PubMed1985

Hypoplastic left heart with complete transposition of the great arteries.

A male newborn infant with hypoplastic left heart and transposition of the great arteries died on the second day of life. The haemodynamic consequences of this malformation are considerably different from those of ordinary hypoplastic left heart syndrome because of pulmonary rather than aortic atresia. In the absence of cross sectional echocardiographic equipment, cardiac catheterisation with angiography is necessary to delineate the anatomical picture. These two conditions have not apparently been reported before in association.

Echocardiography↗
PubMed1985

Tissue distribution and functional correlation of [3H]leukotriene C4 and [3H]leukotriene D4 binding sites in guinea-pig uterus and lung preparations.

To determine the distribution of leukotriene (LT) C4 and LTD4 receptors and functional significance of each receptor, we used [3H]LTC4 and [3H]LTD4 to measure the binding activity in various tissue homogenates and to correlate the relative ability of the LT agonists to inhibit binding with their contractile responses in guinea-pig uterine or lung parenchymal preparations. Guinea-pig brain contained the highest binding activity of 1 to 2 nM [3H] LTC4 followed by small intestine, heart, lung, kidney, uterus, etc., whereas guinea-pig lung had at least 2.7-fold greater [3H] LTD4 binding activity than any other tissues tested. In the brain and uterine homogenates, the rank order of potency for the compounds in competing with [3H]LTC4 for binding sites was LTC4 much greater than LTD4 greater than LTE4 greater than FPL-55712 = arachidonic acid. The in vitro functional study showed that the ability of the LT agonists to produce uterine contraction was in the order of LTC4 greater than LTD4 greater than LTE4, which is compatible with their relative effect for inhibition of uterine or brain [3H]LTC4 binding. In the lung homogenate, either LTC4, LTD4 or LTE4 inhibited effectively [3H]LTD4 binding and the potency order for the [3H]LTD4 competition study was LTD4 greater than LTE4 greater than LTC4 much greater than FPL-55712 greater than arachidonic acid. These LT agonists also produced lung contraction effectively and the difference among their contractile ability was not significant. We conclude that 1) there are distinct functional LTC4 and LTD4 receptors, 2) activation of the LTC4 receptor could account for the uterine contraction due to the LT agonists and 3) the lung contraction induced by LTC4, LTD4 and LTE4 is at least mediated partly by the LTD4 receptor.

Animals↗
PubMed1984

Cardiac hypertrophy secondary to ACTH treatment in children.

The usefulness of ACTH in the treatment of childhood epilepsy is assessed by improvement in the EEG and in the clinical condition. However, pronounced side effects, even serious ones, must be encountered. The most common complications are Cushing syndrome, infections, and arterial hypertension. We report on seven patients with infantile myoclonic seizures, who exhibited myocardial hypertrophy with increased left ventricular function during ACTH treatment. These changes were detected and followed by serial echocardiographic investigations. Within a period of 5 months after the termination of ACTH therapy the abnormal echocardiographic findings disappeared. We believe that the cardiac hypertrophy is ACTH-induced. Based on the various biological effects of ACTH different explanations are proposed: oedema or deposition of glycogen in the myocardial tissue, hyperinsulinism, arterial hypertension and increased inotropic stimulus. Because of our observations, we suggest careful monitoring of children treated with ACTH by performing serial echocardiographic investigations.

Adrenocorticotropic Hormone↗
PubMed1984

A thin quartz cell suitable for vacuum ultraviolet absorption and circular dichroism measurements.

The design of a thin quartz cell suitable for absorption and circular dichroism measurements in the vacuum ultraviolet is described. Important features of the cell are (1) that it can be disassembled for cleaning and reproducibly reassembled with path lengths up to 0.3 mm, and (2) that strain in the windows from the compressed sample can be relieved by a sample overflow port. The latter feature allows the cell to be used for circular dichroism as well as absorption measurements.

Circular Dichroism↗
PubMed1984

Evidence for sequence heterogeneity among the double-stranded RNA segments of Penicillium chrysogenum mycovirus.

We have examined the dsRNA segments of the multipartite virus from Penicillium chrysogenum (ATCC 9480). A fourth RNA segment has been detected recently and, in the present work, we separated the four RNA segments and looked for possible homologies among them by thermal denaturation and electron microscopical heteroduplex studies. Differences were found between the differential melting profiles of the separated RNA segments, and no extensive regions of homology were detected among the various RNA segments by heteroduplex analyses. The results suggest that each RNA segment contains unique sequences. A comparison of the lengths of the RNA segments determined by electron microscopy with those determined by gel electrophoresis suggests that one of the segments has a distinct tertiary structure.

Electrophoresis, Agar Gel↗
PubMed1984

Electron microscopy of bacteriophage phi 6 nucleocapsid: three-dimensional image analysis.

Electron micrographs of bacteriophage phi 6 nucleocapsids, negatively stained by neutralized phosphotungstate and tilted in a goniometer specimen cartridge, proved that the three distinct morphologies seen in the electron microscope are merely three different aspects of a single nucleocapsid structure and strongly suggested that this structure is dodecahedral.

Bacteriophages↗
PubMed1984

[Dilated cardiomyopathy in childhood: intravital differentiation of endocardial fibroelastosis using transvascular endomyocardial biopsy].

Possibly due to the lack of clinical reports concerned with dilated cardiomyopathy in childhood, pediatric cardiologists may inadvertently designate the angiographic finding of a dilated left ventricle as endocardial fibroelastosis. We report historical and noninvasively-obtained data from twelve children, aged seven months to 17 years, with poorly-functioning dilated left ventricles, in whom no differentiation between the two diseases was enabled. Only by means of transvascular endomyocardial biopsies, performed during cardiac catheterization with a 6-F guide-catheter and a Machida bioptome for light and electron microscopal examination, was differentiation achieved among six patients with endocardial fibroelastosis and six with the nonspecific histological findings of muscular hypertrophy, interstitial fibrosis and marked degenerative changes. After exclusion of noxious and inflammatory etiologies, even in childhood, the diagnosis of primary dilated cardiomyopathy must be regarded as established. Since experience previously reported with endocardial fibroelastosis has not been based on histologic documentation of the diagnosis, questions with respect to natural history and prognosis remain unanswered.

Adolescent↗
PubMed1983

The valve of the foramen ovale in interatrial right-to-left shunt: echocardiographic cineangiocardiographic and hemodynamic observations.

In postpartum persistent right-to-left shunt at the atrial level, the valve of the foramen ovale fails to close. As a thin valve-flap the septum primum is pushed to the left during the phases of right atrial pressure predominance and closes to the septum secundum, when left atrial pressure exceeds right atrial pressure. Thus, it performs a marked movement during the cardiac cycle, reflecting the interatrial pressure-flow dynamics. With use of M-mode echocardiography, this movement pattern was studied in 24 patients: 13 with cyanotic heart disease (age 2 days to 21 years) and 11 newborns with persistent transatrial right-to-left shunt due to noncardiac disease. Cardiac defects were confirmed by cardiac catheterization and cineangiocardiography. Interatrial right-to-left shunts were proved by M-mode and 2-dimensional contrast echocardiography. The comparison of the M-mode echocardiographic findings in our patient groups with normal atrial septal movement studied in 20 healthy infants and children revealed considerable differences. The characteristic movement of the valve of the foramen ovale also was compared with results obtained by cineangiography and 2-dimensional echocardiography. Analysis of interatrial blood pressure difference provided a pathophysiologic explanation of the septum primum movement in transatrial right-to-left shunt.

Blood Pressure↗
PubMed1983

[Value of 2-dimensional echocardiography in symptomatic heart diseases in the newborn infant and in early infancy].

From January 1980 to March 1983, 73 distressed newborns and young infants, in whom congenital cardiac defects were suspected, were investigated by two-dimensional echocardiography. The diagnosis in these infants could be re-established later by cardiac catheterization and cineangiocardiography, operation or autopsy. Correct diagnoses were set in 97% of the patients (71 out of 73). Specific echocardiographic criteria for the diagnosis of the individual defects are discussed.

Cardiac Catheterization↗
PubMed1983

[Hypertrophic cardiomyopathy during ACTH treatment].

We report on two infants (two and six month old) with infantile myoclonic seizures, who developed signs of hypertrophic cardiomyopathy (HCM), while receiving ACTH treatment (Tetracosactid=Synacthen Depot). The diagnosis of HCM was established by echocardiography. The first patient (R.M. female). showed signs of cardiac insufficiency and was treated with a beta-blocking agent (Propranolol=Dociton). This led to resolution of the clinical symptoms and reversal of myocardial muscle thickness as determined by echocardiography. The second patient (R.S. female) did not develop cardiac symptoms. A correlation between cardiomyopathy and ACTH treatment is discussed. Based on the various biological effects of ACTH different hypothetical explanations for this correlation are proposed: increased deposition of glycogen, enhanced protein synthesis, oedema of the myocardial tissue and systemic hypertension. Because of the correlation observed between ACTH treatment and the development of cardiomyopathy we recommend regular physical and echocardiographic examinations to detect cardiac involvement during treatment with ACTH.

Adrenocorticotropic Hormone↗
PubMed1983

Construction and properties of an integrable plasmid for Bacillus subtilis.

A plasmid useful for locating the chromosomal site of cloned DNA fragments that lack intrinsic genetic activity, for insertional mutagenesis, for single-copy complementation, and for dominance studies was constructed. Some plasmids containing Bacillus subtilis DNA were only active in transformation when the tetracycline resistance determinant of the plasmid was inactivated. The results suggest that production of the tetracycline gene product is lethal to B. subtilis.

Bacillus subtilis↗
PubMed1983

Enzyme-linked immunosorbent assay (ELISA) and colorimetric determination of cow gamma-glutamyltransferase.

Using specific antibodies of anti-heavy and light forms of bovine kidney gamma-glutamyltransferase, both enzyme forms were determined in some cow body fluids and tissue preparations by enzyme linked immunosorbent assay (ELISA). The mean activity of the light form of gamma-glutamyltransferase in cow sera, new-born calf sera and in cow colostra was 29.2, 612 and 2630 mU/ml respectively. Good correlation was noted between the results obtained by ELISA and by colorimetric method. In supernatants from cow kidney and liver homogenate after incubation at 37 degrees C, a marked increase of the heavy form assayed by ELISA was noted.

Animals↗