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Biomedical subjects

P Grenier

Publications and source records attributed to P Grenier.

At least 19 recordsLinked to original sources
PubMed1992

High-resolution CT of parenchymal lung disease: precise correlation with histologic findings.

To provide a precise correlation between high-resolution computed tomographic (CT) findings and histologic studies of various parenchymal lung diseases, 20 fixed and inflated lungs were studied as follows: (a) Every lung was cut at the corresponding CT level into 1.5-mm-thick sections, (b) selected slices were cut into small blocks to prepare histologic slides, (c) each slide was photographed, and (d) the image of the entire lung section was reconstituted with the enlarged photographs (assembled as in a jigsaw puzzle). Results obtained in cases of normal lungs, pulmonary edema, alveolitis, hypersensitivity pneumonitis, emphysema, Pneumocystis carinii pneumonia, silicosis-asbestosis, and idiopathic pulmonary fibrosis demonstrated the method to be accurate in correlating high-resolution CT findings and the corresponding histologic data.

Alveolitis, Extrinsic Allergic↗
PubMed1992

Pulmonary sarcoidosis: CT assessment of lesion reversibility.

By comparing serial computed tomographic (CT) scans obtained when sarcoidosis was clinically active and after the onset of remission, an attempt was made to differentiate inflammatory from fibrotic lesions in the lungs of patients with sarcoidosis. Twenty patients with pulmonary infiltration seen on their chest radiographs were studied. For each patient, lesions found on the first CT scan were assessed by two observers as being decreased or increased on the second CT scan. Nodules (n = 8), irregularly marginated nodules (n = 5), and alveolar or pseudoalveolar consolidation (n = 5) always disappeared or clearly decreased. Septal lines (n = 10), nonseptal lines (n = 9), and lung distortion (n = 7) remained unchanged or increased. Some findings varied among patients: Micronodules (n = 9) and subpleural thickening (n = 5) disappeared or decreased in sarcoidosis of recent origin. Many findings of pulmonary infiltration seen on the first CT scan can be considered expressions of either inflammatory (reversible CT findings) or fibrotic (irreversible CT findings) lesions.

Adolescent↗
PubMed1991

[Contribution of imaging in the diagnosis of interstitial fibrosing lung diseases].

Standard radiography of the chest shows pulmonary infiltration and is determinant for the diagnosis of chronic diffuse infiltrative lung diseases. Since lung biopsy is an invasive exploratory technique, using computed tomography (CT) in the diagnostic approach is perfectly justified as a direct prolongation of plain radiography. CT identifies patients who, in spite of normal chest X-ray films, do have pulmonary infiltration. It is superior to radiography in suggesting the correct aetiological diagnosis, as it provides signs that are more discriminant than the radiographic signs. It also gives a better approach to the localization of lesions, thereby helping in guiding lung biopsies. Finally, once the diagnosis has been made CT remains useful in evaluating the effects of treatment of pulmonary lesions and in detecting possible complications.

Humans↗
PubMed1991

Ventilatory effects of medical antishock trousers in healthy volunteers.

The ventilatory effects of medical antishock trousers (MAST) were investigated using 10 healthy volunteers. Use of the MAST (60-80 mm Hg) decreased forced expiratory volume (-8% +/- 4%, p less than 0.01), vital capacity (-8% +/- 5%, p less than 0.01), and functional residual capacity (-12% +/- 6%, p less than 0.01) and induced a significant decrease in tidal volume (-30% +/- 17%, p less than 0.05), but minute ventilation was unmodified because of a concomitant increase in respiratory rate (+17% +/- 8%, p less than 0.001). The MAST modified the breathing pattern: the abdominal contribution to ventilation was markedly decreased (-57% +/- 22%, p less than 0.001), suggesting a decrease in the diaphragmatic contribution to ventilation. The MAST increased both the end-expiratory (+131% +/- 115%, p less than 0.01) and inspiratory variation (delta Pgas: +42% +/- 40%, p less than 0.05) of gastric pressure, whereas the end-expiratory and inspiratory variation of esophageal pressure remained unchanged. Because of a higher delta Pgas, the dynamic compliance of the abdominal compartment markedly fell (-77% +/- 10%, p less than 0.001). Transdiaphragmatic pressure (Pdi: +28% +/- 30%, p less than 0.05) significantly increased and the pressure-time index of the diaphragm significantly increased (+32% +/- 32%, p less than 0.05) after inflation of the MAST, suggesting an increase in the diaphragmatic cost of breathing. Inspiratory activity of the parasternal intercostal muscles significantly increased after the MAST was inflated. Computerized tomography showed that the MAST induced a cephalad shift of the diaphragm, which reduced pulmonary height.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Chronic diffuse interstitial lung disease: diagnostic value of chest radiography and high-resolution CT.

The diagnostic value of chest radiography and high-resolution computed tomography (CT) in chronic diffuse interstitial lung disease (CDILD) was assessed in 140 consecutive patients with diffuse infiltration of the lung visible at radiography. Radiographs and CT scans were separately read by three independent observers without knowledge of clinical and pathologic data. The observers listed the three most likely diagnoses and recorded the degree of confidence they had in their choice on a 0%-100% probability scale. Findings at radiography and high-resolution CT were recorded by each observer and were used for a stepwise discriminant analysis between diagnoses. First-choice diagnoses of all three observers that were made with a high level of confidence (probability, greater than or equal to 75%) were more accurate with CT than with radiography (P less than .001). The superiority of high-resolution CT over radiography was most obvious for histiocytosis X and sarcoidosis; in cases of pulmonary fibrosis, CT was not significantly different from radiography. The interobserver agreement for the proposed diagnosis was significantly better with high-resolution CT (P less than .001). Twenty-one of 26 radiographic findings and 21 of 25 CT findings were discriminant. Stepwise discriminant analysis revealed the superiority of CT over radiography, since the ranking of all findings showed that the four most discriminant findings, and eight of the first 12 findings, were revealed with CT.

Adolescent↗
PubMed1990

Pulmonary lymphangiomyomatosis and tuberous sclerosis: comparison of radiographic and thin-section CT findings.

Chest radiographs, thin-section computed tomographic (CT) scans, and results of pulmonary function tests in nine women with pulmonary lymphangiomyomatosis and two women with pulmonary tuberous sclerosis were retrospectively evaluated. In all patients, CT demonstrated thin-walled cysts less than 20 mm in diameter scattered at random in all parts of the lungs. In eight patients, cysts larger than 20 mm in diameter were also present. Lung tissue between cysts appeared normal in all 11 patients, except one with septal lines and dependent alveolar areas of attenuation. CT showed cysts in three patients whose radiographs were normal, and it demonstrated that many lesions that appeared reticular on plain radiographs were actually cysts. CT findings correlated better with the diffusion capacity of the lungs for carbon monoxide than did the plain radiographic findings. CT was more sensitive and more precise than radiography at showing the presence and morphology of lung abnormalities.

Adult↗
PubMed1989

[Diagnosis of diseases of the lung, the mediastinum and the pleura].

Computed tomography of the thorax seems to have proceeded in a straight line from standard radiography of the chest. With its transverse axial sections, it provides a better understanding of spatial displacements and a better localization of thoracic lesions. In most cases, the lesional diagnosis can be approached more directly, so that tomography is no longer used while the number of bronchographies and pulmonary angiographies has been drastically reduced. Finally, computed tomography offers an excellent guidance to the percutaneous or endoscopic collection of samples for cytological and histological examinations. Ultrasounds are particularly used in the diagnosis and drainage of pleural effusions. Magnetic resonance imaging has not yet replaced all other techniques, but it is one of the most helpful examinations for the diagnosis and assessment of mediastinal vascular diseases.

Humans↗
PubMed1989

In-vitro activity of lomefloxacin in comparison with pefloxacin and ofloxacin.

The in-vitro activity of lomefloxacin (SC 47111, NY-198) was investigated by the determination of MICs in agar and in broth, of MBCs in broth, of killing curves and of the duration of the post-antibiotic effect. MICs measured in broth and in agar were almost identical. Lomefloxacin was two- to eight-fold less active against Gram-positive bacteria than ofloxacin. Its activity against Staphylococcus aureus was independent of resistance to penicillin and oxacillin. The activity of lomefloxacin, ofloxacin and pefloxacin was poor against JK corynebacteria. Enterobacteriaceae, Aeromonas spp., Haemophilus, influenzae, Neisseriaceae and Campylobacter jejuni were highly susceptible to the three quinolones investigated. Non-fermenting Gram-negative bacilli were less susceptible. MBCs were within one dilution of the corresponding MICs. The killing rate was very high against Gram-negative bacilli (2.5-4.0 log cfu/ml reduction in 2 h) whereas it was low against Gram-positive bacteria (0.5-1.0 log cfu/ml reduction in 2 h). Emergence of resistance was not observed. The duration of the post-antibiotic effect with Gram-negative bacilli depended on the strain and species (median: 0.9-1.5 h). The post-antibiotic effect was insignificant with Staph. aureus.

Aeromonas↗
PubMed1989

Pulmonary histiocytosis X: evaluation with high-resolution CT.

Eighteen patients with pulmonary lesions of histiocytosis X were studied with high-resolution computed tomography (CT). Thin-walled cysts were found in all but one patient. The other abnormalities included nodules (n = 14), cavitated nodules (n = 3), thick-walled cysts (n = 7), reticulation (n = 4), ground-glass opacities (n = 4), and irregular interfaces (n = 4). The lesions were most often diffuse (n = 16), with a topographic predominance in the upper or middle lung zones in nine patients. Comparison of CT scans and chest radiographs shows that small and large cysts and micronodules are better detected with CT. Comparison of abnormalities found in patients in the early and late stages of the disease, as well as the evolution observed in one case, suggests that CT patterns progress from nodules to cavitated nodules and thick-walled cysts to cysts to confluent cysts.

Adult↗
PubMed1989

Pulmonary sarcoidosis: evaluation with high-resolution CT.

Forty-four patients with histologically confirmed sarcoidosis were prospectively studied with high-resolution computed tomography (CT). Nodules were seen in all cases. They were isolated in 19 cases and associated with other lesions in 25 cases. Other abnormalities were irregular interfaces (n = 18, 41%), linear network (n = 14, 32%), thickening of the pleural surface (n = 9, 20%), ground-glass opacities (n = 7, 16%), lung distortion (n = 11, 25%), traction bronchiectasis (n = 3, 7%), and network of air-filled cavities (n = 3, 7%). Predominant sites of lesions were the upper and middle zones (n = 30, 68%) and posterior zones (n = 13, 30%). Nodular abnormalities were noted at CT in six cases in which the pulmonary parenchyma appeared normal on radiographs. Lung distortion was noted at CT in eight cases without visible fibrosis on chest radiographs. The majority of patients with lung distortion (nine of 11, 82%) had disease of greater than a years duration. CT improved sensitivity for the detection of all types of lesions, mainly lung distortion. Low but significant correlations were found between visual score at CT and total lung capacity, vital capacity, forced expiratory volume in 1 second, and diffusing capacity.

Adult↗
PubMed1988

[Thoracic x-ray computed tomography in pneumology].

Computerized tomography (CT) of the chest is now widely used in pneumological practice. It has completely superseded conventional tomography and reduced the number of bronchographies and pulmonary angiographies. CT is superior to conventional examinations in detecting lymph node enlargements, solid tumours, granulomas, fat deposits, calcifications, pulmonary necrosis and pleural plaques and in demonstrating tumoral limits. In the lung itself, the information provided by CT is of subsegmental accuracy. The new method is capable of diagnosing bronchiectasis and emphysema and evaluating their extension; it also gives a good visualization of chronic interstitial lung lesions.

Humans↗
PubMed1988

Ceftazidime combined with mecillinam: serum bactericidal titres compared with in-vitro synergy against gram-negative bacilli.

In a study of the possible interaction between mecillinam and ceftazidime against Gram-negative bacilli, ten volunteers received on separate days: ceftazidime 20 mg/kg iv in 15 min, mecillinam 10 mg/kg iv in 15 min, or the combination. Blood samples were obtained before and 1 and 6 h after the end of the infusion. Ten strains each of Klebsiella pneumoniae, Serratia marcescens, Citrobacter freundii, Salmonella spp. and Yersinia spp. and nine strains each of Acinetobacter spp., and Pseudomonas aeruginosa were selected. Most of the strains were resistant to ampicillin and cefazolin. Serum levels of ceftazidime and mecillinam were measured by bioassay. Serum bacteriostatic (SBS) and bactericidal (SBA) titration was done in microtitre plates in cation supplemented Mueller-Hinton broth and 50% human serum. Chequerboard titration was also studied to assess in-vitro synergy between ceftazidime and mecillinam in Mueller-Hinton broth with or without 50% serum. The mean serum concentrations (SD) were for mecillinam: 6.1 (1.7) at 1 h, and less than 0.3 at 6 h and for ceftazidime: 36.3 (5.5) at 1 h and less than 5 at 6 h. Identical concentrations were measured for the combination. By chequerboard titration, no synergy occurred for Acinetobacter spp. and Ps. aeruginosa, whereas it was observed in 37/60 (FIC) and 33/60 (FBC) of the strains of other species in Mueller-Hinton; from the strains showing synergy, 28/37 (FIC) and 30/33 (FBC) showed also synergy in Mueller-Hinton with 50% human serum. In SBS and SBA, on the other hand, the combination of mecillinam with ceftazidime showed an additive effect against most Enterobacteriaceae tested, synergy being shown for only 10-35% of tests.(ABSTRACT TRUNCATED AT 250 WORDS)

Amdinocillin↗
PubMed1988

Chest radiography with a shaped filter at 140 kVp: its diagnostic accuracy compared with that of standard radiographs.

The effectiveness of a shaped filter in the detection of mediastinal and retrocardiac abnormalities on 140-kVp posteroanterior chest radiographs was measured by observer-performance testing. A set of 100 radiographs (the filtered and nonfiltered radiographs of 50 patients) were randomly selected from 1000 radiographs obtained from 500 outpatients or hospitalized patients. Five observers independently interpreted the set of radiographs, with one observer interpreting the set twice. Observer performance in detecting abnormalities in the mediastinum and the retrocardiac lung were analyzed by using receiver-operating characteristic techniques. The results indicate that the use of a filter has no significant overall diagnostic advantage (areas under the receiver-operating characteristic curves were 0.90 for the filtered radiographs and 0.89 for the unfiltered radiographs). No significant differences were found in the analysis of the various types or locations of lesions in the mediastinum.

Filtration↗