Lack of effect of ranitidine on rat hepatic blood flow.
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Animals↗
Biomedical subjects
E Melzer
Publications and source records attributed to E Melzer.
Carbon isotope effects on the decarboxylation of carboxylic acids. Comparison of the lactate oxidase reaction and the degradation of pyruvate by H2O2.
The isotope effect at C-1 on the H2O2-catalysed decarboxylation of pyruvate (used as a model reaction for the enzymic reaction) increases between pH 3 and 10 from 1.0007 +/- 0.0004 to 1.0283 +/- 0.0014 (25 degrees C). This result indicates a change in the rate-determining step from formation of the tetrahedral intermediate to decarboxylation of this intermediate. Practically no isotope fractionation at C-1 (1.0011 +/- 0.0002, pH 6.0, 25 degrees C) is found in the lactate oxidase-catalysed decarboxylation of lactate, which is indicative for the existence of an irreversible O2-dependent step prior to the enzyme-catalysed decarboxylation. In addition, the result provides further evidence that dissociation of pyruvate and H2O2 from the enzyme can be excluded. The isotope effect at C-2 of lactate in the enzymic reaction (1.0048 +/- 0.0004) is attributed to the hydrogen transfer step from lactate to the coenzyme.
Carbon Isotopes↗
Carbon isotope effects on the pyruvate dehydrogenase reaction and their importance for relative carbon-13 depletion in lipids.
A method has been developed for the positional 13C isotope analysis of pyruvate and acetate by stepwise quantitative degradation. On its base, the kinetic isotope effects on the pyruvate dehydrogenase reaction (enzymes from Escherichia coli and Saccharomyces cerevisiae) for both of the carbon atoms involved in the bond scission (double isotope effect determination) and on C-3 of pyruvate have been determined. The experimental k12/k13 values with the enzyme from E. coli on C-1 and C-2 of pyruvate are 1.0093 +/- 0.0007 and 1.0213 +/- 0.0017, respectively, and, with the enzyme from S. cerevisiae, the values are 1.0238 +/- 0.0013 and 1.0254 +/- 0.0016, respectively. A secondary isotope effect of 1.0031 +/- 0.0009 on C-3 (CH3-group) was found with both enzymes. The size of the isotope on C-1 indicates that decarboxylation is more rate-determining with the yeast enzyme than with the enzyme from E. coli, although it is not the entirely rate-limiting step in the overall reaction sequence. Assuming appropriate values for the intrinsic isotope effect on the decarboxylation step (k3) and the equilibrium isotope effect on the reversible substrate binding (k1, k2), one can calculate values for the partitioning factor R (k3/k2: E. coli enzyme 4.67, S. cerevisiae enzyme 1.14) and the intrinsic isotope effects related to the carbonyl-C (k1/k'1 = 1.019; k3/k'3 = 1.033). The isotope fractionation at C-2 of pyruvate gives strong evidence that the well known relative carbon-13 depletion in lipids from biological material is mainly caused by the isotope effect on the pyruvate dehydrogenase reaction. In addition, our results indicate an alternating 13C abundance in fatty acids, that has already been verified in some cases.
Carbon Isotopes↗
Anapleurotic CO(2) Fixation by Phosphoenolpyruvate Carboxylase in C(3) Plants.
The role of phosphoenolpyruvate carboxylase in photosynthesis in the C(3) plant Nicotiana tabacum has been probed by measurement of the (13)C content of various materials. Whole leaf and purified ribulose bisphosphate carboxylase are within the range expected for C(3) plants. Aspartic acid purified following acid hydrolysis of this ribulose bisphosphate carboxylase is enriched in (13)C compared to whole protein. Carbons 1-3 of this aspartic acid are in the normal C(3) range, but carbon-4 (obtained by treatment of the aspartic acid with aspartate beta-decarboxylase) has an isotopic composition in the range expected for products of C(4) photosynthesis (-5 per thousand), and it appears that more than half of the aspartic acid is synthesized by phosphoenolpyruvate carboxylase using atmospheric CO(2)/HCO(3) (-). Thus, a primary role of phosphoenolpyruvate carboxylase in C(3) plants appears to be the anapleurotic synthesis of four-carbon acids.
Journal Article↗
Severe cholestatic jaundice due to sulpiride.
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Cholestasis, Intrahepatic↗
Pulmonary manifestations of temporal arteritis.
Temporal arteritis is a well-recognized multi-systemic disease. Pulmonary manifestations, however, are extremely rare. In two patients with biopsy-proven temporal arteritis, lung involvement was observed. One patient presented with multinodular pulmonary lesions, while the second had a diffuse interstitial pattern. Both patients responded well to corticosteroid treatment. In a review of the literature, only four additional cases associating lung involvement with temporal arteritis were found. The possibility of primary pulmonary vasculitis should be considered in elderly patients with temporal arteritis.
Adrenal Cortex Hormones↗
Pneumococcal bacteremia--no change in mortality in 30 years: analysis of 104 cases and review of the literature.
We evaluated 104 cases of pneumococcal bacteremia retrospectively: 55 adults and 49 children. The overall mortality rate was 33% in adults, and 6% in children. Mortality was associated with old age, severe underlying disease, vague clinical presentation, multilobar pneumonia, leukopenia and metabolic acidosis. Both vigorous treatment with mechanical ventilation devices, vasopressors and steroids, and sophisticated monitoring in the Intensive Care Unit did not improve survival. In six cases (5.8%) the pneumococcus was resistant to penicillin G. In reviewing the literature of the last 30 years, no change in mortality rate was noted. Vaccination of population at risk is highly recommended.
Adolescent↗
Disseminated intravascular coagulation and hypopotassemia associated with blast lung injury.
Forty six people were injured by a large explosive charge detonated in a Jerusalem bus. Four were killed instantaneously and 22 needed hospital care. We describe our experience in five patients with blast lung injury (BLI), all of whom survived in spite of severe respiratory failure requiring mechanical ventilation. Disseminated intravascular clotting (DIC) developed in three of the five patients and significant hypopotassemia ranging from 2.2 to 2.9 mEq/L in four. These two complications have not been previously described in association with BLI. Both DIC and hypopotassemia responded to replacement therapy. Vigorous treatment of respiratory failure, early recognition, and prompt correction of hemostatic and electrolyte abnormalities may have contributed to the avoidance of fatalities among the five patients with severe blast injury.
Adult↗
Body positional effect on gas exchange in unilateral pleural effusion.
The positional effect on gas exchange was studied in eight patients who had unilateral pleural fluid without clinical or radiologic evidence of parenchymal lung disease. In all eight patients, PaO2 values were higher when the lung with the pleural fluid was uppermost. The mean PaO2 in this position was 71.9 +/- 9.3 mm Hg (mean +/- SE) compared with 66.7 +/- 8.7 mm Hg in the lateral decubitus position with the pleural fluid lowermost. The mean difference in PaO2 between the two positions was 5.1 +/- mm Hg (p less than 0.005). Larger positional differences were found in the patients with the smallest pleural effusions. These results are probably due to perfusion of areas of unventilated lung, accentuated by gravity with a consequent increase in shunting. A large effusion also causes a decrease in perfusion, so that ventilation-perfusion mismatching is decreased and the positional effect on gas exchange diminished.
Aged↗
[Chondrodystrophia calcificans congenita observed during six years (author's transl)].
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Alopecia↗
Some characteristics of the purinergic nervous system in normal and sensitized airway smooth muscle.
Supramaximal electrical field stimulation was employed to produce biphasic response in segments of cervical and thoracic tracheas and in first generation of bronchi isolated from guinea pigs. This response consists of contraction (as measured by maximal active tension, ATmax) followed by relaxation (as measured by maximal active relaxation, ARmax). First, the effect of electrical stimulation was studied in relation to frequency and duration of impulse. Highest degree of relaxation (ARmax) was achieved with a frequency of stimulus of 40 pulses per sec for segments of trachea, and 60 pulses per sec for first generation bronchi, and with duration of pulse of 1.0 msec for segments of trachea, and 2.0-2.5 msec for bronchi, and with duration of pulse of 1.0 msec for segments of trachea, and 2.0-2.5 msec for bronchi. Secondly, mean length-tension relationship was determined. It was found that maximal relaxation (ARmax) occurred at 160 +/- 5% of Lmax in case of tracheal segments and 160 +/- 2% of Lmax for bronchial preparations. Using propranolol pretreatment (10(-4) M), which inhibited participation of adrenergic receptors in relaxation, it was determined that approximately 50% relaxation of airway smooth muscle of the normal guinea pig is mediated through the purinergic nervous system. Both tracheas and bronchi isolated from sensitized guinea pigs, chronically exposed to antigen, showed a significant decrease in overall relaxation (P less than 0.01). However, the per cent decrease in relaxation after propranolol was not different in sensitized animals than that found in controls. The data suggest that relaxation of segments of airways isolated from animals chronically exposed to antigen is decreased in consequence of alterations in both purinergic and adrenergic nervous systems.
Action Potentials↗
Decrease of respiratory muscle strength and static lung volumes in obese asthmatics.
Ten obese patients with steroid-dependent bronchial asthma were studied. All were female nonsmokers and all had normal chest roentgenograms. The patients were divided into 2 groups according to their total lung capacity (TLC), i.e., those with decreased TLC (N = 4) and those with normal TLC (n = 6). It was found that patients with low TLC had decreased respiratory muscle strength, as measured by maximal inspiratory esophageal pressure, and that the pressure-volume (P-V) curve of the lung was shifted downward and to the right. There were no differences between the 2 groups in degree of airflow limitation, in per cent increase in body weight, and in duration and dose of steroid therapy. All had normal values of diffusion, corrected for alveolar volume. It is concluded that respiratory muscle strength is an important factor in maintaining normal static lung volumes. The data suggest that the combination of obesity and steroid therapy can cause a decrease in respiratory muscle strength in certain obese patients with bronchial asthma. The change in P-V curve seen in the patients with decreased TLC may be secondary to the decrease in static lung volumes.
17-Hydroxycorticosteroids↗
A dose-response-like relationship between minute ventilation and exercise-induced bronchoconstriction in young asthmatic patients.
Seven adolescent patients with bronchial asthma performed bicycle exercise tests on several occasions, within 1 week. After the determination of baseline pulmonary function (using spirometry, maximal expiratory flow-volume curves and body plethysmography), all subjects were exercised on the bicycle ergometer for 10 min. On each occasion a different level of minute ventilation (VE, 1/min) was achieved, because of different work performed. Following each exercise test, the degree of exercise-induced bronchoconstriction was assessed. It was found that the degree of bronchoconstriction, as measured by pulmonary function tests, is function of VE measured during exercise. A dose-response-like relationship, i.e., level of VE vs. bronchoconstrictive response, seems to be an important individual characteristic of the airway reactivity of young patients with bronchial asthma.
Adolescent↗
[Is congenital hour-glass bladder always a malformation? (author's transl)].
Hour-glass bladder was detected by X-ray investigation in a newborn female infant with delayed postpartum micturition. No signs of difficulty in micturition or urinary tract infection were subsequently detected. Control X-ray investigation at the age of 5 1/2 months showed a completely normal-shaped urinary bladder. This finding contrasts with the general opinion that hour-glass bladder is caused by a congenital malformation.
Citrobacter↗
[Polycythaemia as sole symptom of renal adenoma (author's transl)].
In two children, a 9 year-old boy and a 10 1/2 year-old girl, who presented with polycythaemia as the only symptom, the expected renal tumour was only found after exclusion of all other causes of polycythaemia. The delay in diagnosis was caused by technically inadequate intravenous urograms, which were erroneously passed as normal. In one child low kv X-ray exposition of the kidneys led to the diagnosis of a renal tumour. In the other child high-dose urography and tomography gave the indication for selective angiography. Normalization of the red blood count postoperatively verifies the connection between preoperative erythrocytosis and the renal tumour. Histologically both cases proved to be renal adenomas, which are extremely rare in childhood.
Adenoma↗
[Calcification of the urinary bladder, a rare finding in the newborn (author's transl)].
The rare X-ray finding of urinary bladder wall calcifications in a newborn is reported. The newborn suffered from micturition disturbance caused by urethral valves, bilateral hydroureter and bilateral hydronephrosis. No possible definite cause for the calcification of the bladder wall could be found. The calcifications could never be detected by X-ray after the age of 5 months.
Calcinosis↗
[Wilson-Mikity-syndrome in twins (author's transl)].
The course of a Wilson-Mikity-syndrome in biovular twins born 19 weeks prematurely is reported. The disease started in the second week of life, reached its peak in the ninth week and it was complicated by a bronchopneumonia as well as a spastic bronchitis resulting in cardiac failure in both infants. On infant suffered spontaneous fracture of the ribs. Both patients were stationary for 26 weeks and 31 weeks respectively. A routine-examination at the age of 1 year revealed still distinct lung abnormalities, but nevertheless showing a tendency of improvement. Signs of right ventricular hypertrophy were found in the ECG of both children but more distinctly in the girl. The neurological development of the infants were found to be normal.
Bronchitis↗