Biomedical subjects
C Perret
Publications and source records attributed to C Perret.
Evidence for pancreas injury in adult respiratory distress syndrome.
The purpose of this study was to investigate the relation between serum lipase (LP), serum immunoreactive trypsin (IRT), and its inhibitors in patients with adult respiratory distress syndrome (ARDS) of diverse origin and to compare their time course with other acute conditions. The IRT and LP levels were determined at regular intervals in 41 patients hospitalized in the intensive respiratory unit with ARDS (n = 9), acute pancreatitis (n = 5), shock (n = 9), bronchopneumonia (n = 10), or acute cardiogenic pulmonary edema (n = 8). Several trypsin inhibitors were measured simultaneously: serum trypsin inhibitory capacity (TIC), alpha 1-antitrypsin, alpha 2-macroglobulin, and antithrombin III. Concomitantly, angiotensin-converting enzyme (ACE) activity was determined as a potential marker of the endothelial injury. A respective 19- and 13-fold increase in IRT and LP values were observed in patients with ARDS after a mean evolution of 6 days; similar increases were seen in patients with pancreatitis. These values were significantly higher than those observed in the other conditions studied. In patients with ARDS and acute pancreatitis, the evolution of IRT and LP values were associated with a sixfold rise in TIC. A low TIC/IRT ratio in patients with ARDS appeared to be an index of poor prognosis. Conversely, ACE activity evolution was characterized by an early decrease in all the conditions studied. These observations indicate that there is an acute delayed pancreas injury in ARDS. Thus, the release of pancreatic enzymes are not reliable markers of the early evolution of the disease but they may represent secondary mediators for enhancement of the increased endothelial permeability.
Reduced pulmonary capillary blood volume as a long-term sequel of ARDS.
Lung function was evaluated in nine survivors of ARDS. All patients were asymptomatic at rest at the time of the study, ie, 5.5 to 19 months after extubation (mean 12.5). Six had mild to moderate exertional dyspnea. Chest x-ray films showed no gross parenchymal abnormalities. Spirometry and pulmonary mechanics were either normal or minimally altered, particularly in smokers. At submaximal exercise levels, effort was limited by tachycardia in eight patients; one subject showed ventilatory and cardiovascular limitations. It was concluded that spirometry and pulmonary mechanics are restored to normal within six months after extubation, and gas exchange abnormalities persist after ARDS and might be related to intrapulmonary shunts at rest, whereas during exercise a decreased pulmonary capillary blood volume might be the primary factor.
[Molecular approach to the action of vitamin D in man].
Some applications to man of specific markers of the molecular action of vitamin D (1.25(OH)2D3 receptors and antibodies to hormone-dependent proteins (CaBP and cDNA] are reported in this study. On case of type II vitamin-dependent rickets was characterized by 1.25(OH)2D3 plasma level greater than 250 pg/ml and a ten-fold decrease of the number of binding sites of the hormone in cultured skin fibroblasts. We propose that CaBP 28K and/or 9K-containing cells, such as Purkinje's cells and chondroblasts may be targets for vitamin D action. Detection in fetuses, from the 20th week of gestation, of CaBP 9K messenger RNA in the duodenum and sternum and presence of CaBP 28K and 9K in the chondroblasts of the upper extremity of tibia, suggest that vitamin D acts on the nucleus of its target-cells during fetal development. Finally, discovery of the gene of CaBP 9K in man opens the prospect of studies which will improve the understanding of the mechanism of action of vitamin D.
[Conservative treatment of melanomas of the choroid].
Explore the source record for details and available documents.
[Expectations in the vasodilator treatment of secondary pulmonary hypertension].
Explore the source record for details and available documents.
Discharges of forelimb spindle primary afferents during locomotor activity in the decorticate cat.
In the acute decorticate cat, the discharge patterns of single spindle primary afferents from various forelimb muscles during locomotion have been examined in relation to the extrafusal activity. In a given muscle under isometric conditions, the activation of spindle primary endings was closely related to that of extrafusal muscle fibers. Since this increase in spindle discharge could occur in the absence of detectable electromyographic activity in the parent muscle, it resulted, at least to some extent from an enhanced activity in gamma efferents. The data are discussed in relation to previous studies of forelimb efferent activity and hindlimb fusimotor control in the same preparation.
An extreme form of the hyperdynamic syndrome in septic shock.
We classified 41 patients in septic shock on the basis of cardiac index (CI) after volume expansion with plasma protein solution, in order to obtain adequate filling pressures. Five had decreased CI (less than 3.5 1/min per m2), 31 had moderately increased CI (3.5 - 7.0 1/min per m2) and 5 had extreme hyperdynamic shock with CI superior to 7.0 1/min per m2. Among the patients with increased CI, those with extreme hyperdynamic state (EHS) had lower total systemic and pulmonary arteriolar resistances (370 vs 658 and 52 vs 119 dynes X s X cm-5, respectively) and a higher stroke index (67 vs 46 ml/m2), in spite of similar right atrial pressures. In this latter group, blood lactate was higher (6.5 vs 2.1 mmol/l), acidosis was more severe and coagulation disorders more pronounced; all five patients maintained an extremely high CI until death, which supervened after a brief episode of sinus bradycardia. A similar clinical course was rarely observed in the remaining moderately hyperdynamic group, in which mortality rate was significantly lower (35%). Three of five patients with EHS (compared to 2 of 31 in the moderately hyperdynamic group) had liver cirrhosis, the fourth died of fulminant meningococcemia and the fifth had prolonged polymicrobial bacteremia before adequate treatment was begun. Thus, underlying liver disease or particularly severe and uncontrolled infection seems to predispose to EHS. It is concluded that septic shock with extremely high cardiac output and excessively low peripheral resistances represents a distinct subset with more severe metabolic and coagulation disorders, an unusual hemodynamic evolution and a particularly poor prognosis.
Diagnostic approach to pulmonary embolism: our strategy.
The nonspecificity and variety of clinical features in acute pulmonary embolism account for a high suspicion rate, with a further exclusion of the diagnosis in up to 80% of cases. Arterial blood gas analysis and other laboratory tests are highly non-specific, and suggestive signs on the electrocardiogram are uncommon. The plain chest X-ray often yields valuable information. Lung scan, when normal, has the great advantage of excluding pulmonary embolism. At present, no procedure has superseded pulmonary angiography to attest the presence of emboli. Angiography will probably gain widespread acceptance with the larger use of thrombolysis.
Mechanical controlled hypoventilation in status asthmaticus.
This study reports the results obtained with mechanical ventilation in severe respiratory failure secondary to status asthmaticus. Of the 159 patients with status asthmaticus admitted to the Intensive Respiratory Unit over a 5-yr period, 26 required mechanical ventilation for a total of 34 episodes of acute respiratory acidosis. At the time of intubation, 10 patients were in coma and 5 were in respiratory arrest. Controlled mechanical ventilation was maintained for a mean of 2.5 days. Complications were few and reversible. All patients survived. These favorable results are attributed to a new strategy: mechanical ventilation is used to obtain a correction of hypoxemia with hyperoxic mixtures without attempting to restore an adequate alveolar ventilation. The respirator is adjusted to avoid high airway pressures, which appear to be more dangerous than persistent hypercapnia itself. Correction of hypercapnia is obtained later when bronchial obstruction relief provides better conditions of ventilation-perfusion distribution. So the risks of barotrauma and cardiocirculatory failure, which are frequently reported as fatal complications, appear to be significantly decreased.
Renin and the complications of acute myocardial infarction.
To determine whether plasma renin activity in addition to catecholamines could be used as risk indicators, these parameters were measured in 19 patients with acute myocardial infarction. During the course of hospitalization, five patients developed ventricular fibrillation and three, cardiogenic shock. On admission, heart rate, plasma norepinephrine, epinephrine, and renin levels of these eight patients were significantly higher than those of the other patients with uncomplicated course. Peak creatine kinase MB activity was positively related to initial plasma renin activity (r = 0.62, p less than 0.01). Thus, the patients with the highest sympathetic activity following an acute myocardial infarction also had the highest plasma renin levels. They seem particularly prone to develop large infarcts and life-threatening complications.
Immunohistochemical analysis of T-cell subsets in the peribulbar and intrabulbar infiltrates of alopecia areata.
In 11 patients with untreated alopecia areata in the progressive stage of the disease, an in situ analysis of the inflammatory infiltrate of the hair bulbs was performed by means of different monoclonal antibodies. Most of the peribulbar cells reacted with the pan T-cell antibodies OKT 3 and Lyt 3. Staining for T-cell subsets revealed that the proportion of OKT 4+ cells was about fourfold higher than that of OKT 8+ cells. Almost all of the T cells were OKIa1+, indicating that they were in an activated state. In four of the 11 cases, both subsets of T lymphocytes were also found to infiltrate the hair matrix itself. These results would appear to be consistent with the assumption that alopecia areata is caused by a T cell mediated autoimmune mechanism.
[Intracoronary thrombolysis as a treatment for evolving myocardial infarction].
Myocardial infarction is almost always the consequence of a thrombotic obstruction of one or more coronary arteries. We report our experience with the first 24 cases of intracoronary thrombolysis for recanalization of obstructed coronary arteries. 19 cases were successful, 1 case was partially successful and in 4 instances no reopening was observed. The amount of streptokinase used was 206 000 +/- 107 000 units, and reperfusion was achieved after 37 +/- 27.5 minutes. Recanalization of the vessel was accompanied by cessation of precordial pain and partial or complete normalization of the electrocardiogram. In one case bypass surgery was necessary because of reocclusion. Left ventricular function improvement after thrombolysis was dependent on the time-lag between occlusion and recanalization. These observations confirm others' experience that intracoronary thrombolysis appears to have favorable effects in patients with evolving myocardial infarction.
[Measuring bronchial obstruction in intensive care].
The nature and degree of bronchial obstruction is not easy to assess in the intensive care unit. The classic airway resistance measurement technique cannot be performed without heavy equipment and the patient's cooperation. On the basis of the forced oscillations technique, measurement of acoustical respiratory impedance is an extension, in a higher frequency range, of earlier dynamic compliance measurements, which are known to be sensitive to peripheral airway obstruction but unsuitable for critically ill patients. The main advantage of respiratory impedance measurement is simplicity, since the patient simply breathes freely for a minute in the apparatus. This method contributes an effective means of quantifying evolution and treatment during an asthmatic attack. It can also be used to monitor left heart failure.
[Reduction of pulmonary capillary volume following acute respiratory distress syndrome in adults].
Lung function after adult respiratory distress syndrome was evaluated in 8 survivors whose ages ranged from 20 to 54 years. At the time of the study, 5.5 to 19 months after extubation, all patients were asymptomatic at rest but 6 had mild to moderate exertional dyspnea. Physical examination was normal in 7 patients; lung volumes, flow rates and pulmonary mechanics were minimally altered, mainly in smokers. Chest X-rays showed no major abnormalities. On graded submaximal exercise test, performance was limited by tachycardia and not by ventilation. Resting arterial PO2 was low in 6 patients and increased only in one patient during submaximal exercise. The capillary blood volume was decreased in all patients. The mechanisms of hypoxia during exercise and decreased capillary blood volume, the latter apparently unrelated either to pulmonary microvascular obstruction or to fibrosis, remain unexplained. It is concluded that lung volumes and pulmonary mechanics are restored to normal within 6 months after ARDS, whereas gas exchanges persist after ARDS and are associated with a reduced pulmonary blood volume.
Pulmonary cytology in foundry workers.
The prevalence of cellular atypias has been determined in relation to smoking history, age and type of work of male foundry workers in different departments of a foundry. Participation of the workers was 95%. Out of 677 workers, 528 had results within normal limits, 36 showed mild atypical metaplasia while 4 persons got moderate atypias; 48 individuals showed unsatisfactory results and 61 did not complete the tests. Prevalence of abnormal findings ranged from 4.2% in non-smokers to 7.8% in smokers of more than 21 cigarettes. The prevalence also increased with age in smokers only. Variations in prevalence associated with employment in different departments of the foundry varied little and were not statistically significant.
Rat duodenal calcium-binding protein messenger RNA: induction by 1,25-dihydroxyvitamin D3.
To extend our previous observations on the regulation of CaBP biosynthesis by 1,25-dihydroxyvitamin D3, we have studied the specific mRNA encoding this protein in vitamin D-deficient and in vitamin D-repleted rats as well as the rate of its induction after a single injection of 1,25(OH)2D3 to vitamin D-deficient animals. The CaBP-mRNA was quantified by translation in a cell-free reticulocyte lysate system. CaBP-mRNA activity and cytoplasmic CaBP (measured by radioimmunoassay), dramatically decreased in rats previously fed a vitamin D-free diet for 5 weeks but neither parameter was zero. In vitamin D-deficient rats, a single injection of 1,25(OH)2D3 led to an increase in CaBP-mRNA activity within 2 h. This CaBP-mRNA activity peaked at about 4-6 h and thereafter declined to low value by 48 h, and the changes in mRNA activity always preceded the changes in cytosolic CaBP concentration. These results indicate that the induction of CaBP biosynthesis results from a 1,25(OH)2D3-induced increase in the levels of total cellular CaBP-mRNA activity and are, therefore, consistent with a transcriptional regulation of CaBP biosynthesis by 1,25(OH)2D3. This study also shows that the production of many other proteins seem to be under the control of vitamin D3.
Centrally generated pattern of motoneuron activity during locomotion in the cat.
Explore the source record for details and available documents.