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Biomedical subjects

P Collard

Publications and source records attributed to P Collard.

At least 37 records · Page 2Linked to original sources
PubMed1995

Normal pregnancy in primary alveolar hypoventilation treated with nocturnal nasal intermittent positive pressure ventilation.

Nocturnal nasal intermittent positive pressure ventilation (NIPPV) is increasingly used to treat chronic respiratory failure in a wide variety of conditions (myopathies, Ondine's curse, kyphoscoliosis, etc.) and allows a normal everyday life. Some of these diseases affect women of childbearing age. We report on a young woman suffering from primary alveolar hypoventilation, who presented with limitation of daytime activities, severe oxygen desaturation during sleep, polycythaemia and pulmonary hypertension. These abnormalities completely reversed after a few months of NIPPV applied through a nasal mask. Whilst under ventilatory assistance during sleep, she had an uneventful pregnancy and delivery of a normal baby. We suggest that in selected patients requiring NIPPV, pregnancy can be contemplated with a reasonable level of safety both for the mother and the child, provided that adequate mechanical ventilatory assistance during sleep is maintained throughout pregnancy.

Adult↗
PubMed1994

Single breath diffusing capacity for carbon monoxide in stable asthma.

BACKGROUND: Single breath diffusing capacity for carbon monoxide (Dco) is commonly used as a simple method of assessing overall pulmonary gas exchange properties. Studies of Dco in bronchial asthma have yielded conflicting results. OBJECTIVE: To study Dco and to determine the factors influencing Dco in patients with asthma. METHODS: Dco was prospectively measured in 80 consecutive never-smoker patients with uncomplicated stable asthma. The topographic distribution of lung perfusion was determined in 10 asthmatics and 10 controls, with a 133Xe radionuclide scan. RESULTS: The mean (SD) value of Dco was increased to 117 (17) percent of predicted values; individual values were either within or above normal limits; diffusion was also elevated at 116 (19) percent after correction for alveolar volume (transfer coefficient, D/VA). The Dco was not correlated with atopic status, duration of asthma, or results of spirometric tests; there was a weak negative correlation between D/VA and FEV1 or residual volume. There was a better perfusion of the upper zones of the lungs in asthmatics as compared with controls. Among the asthmatics, there was a strong positive correlation between Dco and the apex to base perfusion ratio (r = 0.975). CONCLUSIONS: Dco is normal or high among never smoker patients with uncomplicated asthma; elevated Dco may be attributed to a better perfusion of the apices of teh lungs; the latter could result from two mutually nonexclusive mechanisms: an increase in pulmonary arterial pressure and/or a more negative pleural pressure generated during inspiration as a consequence of bronchial narrowing. The unexpected finding of high Dco should raise the possibility of bronchial asthma in patients with otherwise undiagnosed conditions.

Adult↗
PubMed1993

Rib biopsy.

Explore the source record for details and available documents.

Biopsy↗
PubMed1993

Management of simple snoring in adults.

The management of simple snoring in adults is reviewed. Snoring is associated with oscillations of the soft palate and adjacent structures, as a consequence of a critically reduced pharyngeal cross-sectional area under conditions of sleep-induced flow limitation. Anatomical and physiological factors resulting in upper airway collapse and snoring are reviewed. The conservative treatment of snoring encompasses weight loss, alcohol and sedatives avoidance, as well as smoking cessation. Nasal obstruction should be relieved, either medically or surgically. If these measures fail, polysomnography should be performed. Patients with obstructive sleep apnoea should be offered nasal continuous positive airway pressure therapy. Uvulopalatopharyngoplasty can be proposed to nonapnoeic snorers, with a good chance of success, as far as reported snoring is concerned. Unfortunately, this has not been confirmed by objective recordings, and long-term results have not been adequately studied.

Humans↗
PubMed1992

Treatment of relapse of small cell lung cancer in selected patients with the initial combination chemotherapy carboplatin, etoposide, and epirubicin.

BACKGROUND: Relapse of small cell lung cancer is not usually treated with further chemotherapy as results are considered to be disappointing. METHODS AND RESULTS: Six patients with relapse of small cell lung cancer after a complete initial response and remission of more than one year responded to repeat treatment with the initial chemotherapy comprising carboplatin, etoposide, and epirubicin. The second remission ranged from six months to more than 15 months. CONCLUSION: In patients with a relapse of small cell lung cancer after a complete initial response and prolonged remission retreatment with the initial combination chemotherapy cannot be dismissed and requires further study.

Aged↗
PubMed1992

A rare case of bronchial stenosis in Wegener's granulomatosis. Dramatic response to intravenous cyclophosphamide and oral cotrimoxazole.

We describe a patient with Wegener's granulomatosis (WG) who developed as the only pulmonary manifestation a severe proximal bronchial stenosis despite conventional treatment with steroids and oral cyclophosphamide. The patient subsequently responded to a combined therapy with intravenous (IV) cyclophosphamide and oral cotrimoxazole. We stress the rarity of bronchial involvement in WG and discuss the role of IV cyclophosphamide and cotrimoxazole in the management of this disease.

Administration, Oral↗
PubMed1991

Cultured peripheral blood mononuclear cells derived from patients with acute severe asthma ("status asthmaticus") spontaneously elaborate a neutrophil chemotactic activity distinct from interleukin-8.

Peripheral blood mononuclear cells (PBMC) isolated from patients with acute severe asthma on the day of admission to hospital were cultured in vitro in serum-free medium in the absence of mitogenic stimulants for as long as 72 h. PBMC isolated from control groups (mild asthma, chronic obstructive airway disease, normal subjects) were cultured in a similar fashion. After incubation, the culture supernatants were tested for neutrophil chemotactic activity (NCA) using a modified Boyden chamber technique. PBMC from patients with acute severe asthma elaborated significantly greater amounts of NCA into the culture supernatants as compared with all three control groups (p less than 0.01). The amounts of PBMC-derived NCA from the same patients after 7 days of hospital therapy and clinical improvement were reduced (p less than 0.01). A correlation was observed between the extent of reduction in spontaneous release of NCA by PBMC derived from patients with acute severe asthma and the degree of clinical improvement of their asthma (p less than 0.02). Both monocytes and lymphocytes, when cultured separately, released NCA in amounts sufficient to account for the total activity released by unfractionated PBMC. NCA in PBMC culture supernatants accumulated progressively with time, a process inhibited in a dose-dependent fashion by cycloheximide. The amounts of NCA in culture supernatants did not correlate with the concentrations of histamine in lysates of the PBMC prepared just prior to culture.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1989

[Local tumefaction of the gallbladder wall due to pancreatic heterotopia].

A 38-year-old woman was examined because of vague abdominal symptoms. Cholecystography and US studies demonstrated a lobulated tumor, 14 mm in length, with a homogeneous structure, sharp limits, adjacent to the posterior wall of the gallbladder and producing no acoustic shadow. Pathological examination demonstrated subserosal pancreatic heteropia. More than 22 different kinds of focal lesions affecting the gallbladder wall have been described. Unfortunately, no clinical or US criteria allow a definite diagnosis. Only the size makes a difference: more than 94% of the adenomas measuring less than 10 mm are benign whereas 88% of the malignant lesions are over 10 mm. Considering the absence of specific criteria, surgical removal is therefore indicated for lesions over 10 mm.

Adult↗
PubMed1989

Improvement of oxygen delivery in severe hypoxaemia by a reservoir cannula.

In 36 severely hypoxaemic patients (arterial oxygen tension (PaO2) less than 7.3 kPa or 55 mmHg), candidates for long-term oxygen therapy, we compared the effectiveness of three oxygen-delivery systems, the standard nasal prongs, a so-called oxygen-conserving reservoir device ("Oxymizer Pendant") and the reference pharyngeal catheter, at a preset flow rate of 2 l.min-1. After 30 min, the conserving device (OX) was at least as efficient as the pharyngeal catheter (PC) and did significantly better than the nasal prongs (NP), the mean increments in PaO2 and arterial oxygen saturation (SaO2) being, respectively, 1.1 kPa (8.1 mmHg) and 1.3% higher with OX than with NP. Twenty patients did not reach the target level of 8.6 kPa (65 mmHg) PaO2 with the nasal prongs, but the reservoir cannula allowed nine of these "refractory" patients to hit this therapeutic goal, a result indicating a clear trend towards improved immediate oxygen response. Although initially designed to spare gas, we suggest that a reservoir cannula could serve another purpose, namely to optimize oxygenation in patients treated by an oxygen concentrator. Indeed, since the oxygen flow rate cannot be reliably increased over 3 l.min-1 with the available oxygen concentrators, the reservoir device could be more effective in some selected patients whose hypoxaemia cannot be adequately corrected by standard nasal prongs.

Blood Gas Analysis↗
PubMed1987

Comparative effects on hemodynamics of enoximone (MDL 17,043), dobutamine and nitroprusside in severe congestive heart failure.

To assess their comparative effects on hemodynamics, nitroprusside, dobutamine and enoximone were sequentially administered to 10 patients with severe congestive heart failure. Nitroprusside, dobutamine (at 10 micrograms/kg/min) and enoximone (at 2 mg/kg) increased stroke volume index to a similar extent (31%, 34% and 36%, respectively). Enoximone produced less tachycardia than dobutamine and, consequently, a smaller improvement in cardiac index. Mean arterial pressure was not altered by dobutamine but was reduced 9% by enoximone, 2 mg/kg. This finding accounts for the larger (although not significant) increase in left ventricular stroke work index observed with dobutamine compared with enoximone. Ventricular filling pressures and vascular resistances were significantly decreased by all 3 drugs (p = 0.001). All 3 drugs improved cardiac pump function when assessed by the increase in stroke index to a similar extent; however, enoximone (2 mg/kg) resulted in less hypotension than nitroprusside (mean arterial pressure -9% vs -22%, p = 0.0001) and in less tachycardia than dobutamine 10 micrograms/kg/min. Those differences in mode of action account for the variations observed in the heart rate-blood pressure product (dobutamine 10 micrograms/kg/min, +18%, enoximone 2 mg/kg, -5%, p = 0.003). Enoximone thus appears to be of great value in the management of severe congestive heart failure by its combination of vasodilatory and inotropic properties. Enoximone (2 mg/kg) provides a clinically significant increase in cardiac index, a clear reduction of ventricular filling pressures, a moderate reduction of mean arterial pressure and only minor changes of heart rate and of rate pressure product.

Aged↗
PubMed1985

The 15O continuous-inhalation method: correction for intravascular signal using C15O.

Cerebral oxygen metabolism (CMRO2) and fractional extraction (OEF) regional values obtained using the 15O steady-state method and positron-emission tomography (PET) were corrected for the activity remaining in blood vessels (a source of overestimation of the OEF neglected in the simple steady-state model) using an additional scan during continuous inhalation of nontoxic amounts of carbon monoxide labeled with 15O (C15O). The method was applied to ten serial PET studies. In normal tissue, OEF overestimation was 11% +/- 2.6% and 9% +/- 2.0% in gray and white matter, respectively. In pathological tissue, the OEF overestimation was, on average, higher than in normal tissue (28% +/- 17% in the core of lesions), but more variable. In both normal and abnormal tissue, however, it was found that (1) the lower the real OEF, the larger the correction applied, and (2) the correction appears to be particularly necessary in situations of abnormally low OEF. The use of C15O continuous inhalation is a simple, direct, and accurate method for blood-activity correction when the 15O steady-state technique is employed to study pathophysiology.

Aged↗
PubMed1985

Growth kinetics of mixed culture in salmonella enrichment media.

A technique for investigating the kinetics of salmonella enrichment is reported. Its use with four enrichment media (Rappaport's medium, Muller-Kauffmann tetrathionate broth (MKT) tetrathionate broth and selenite F) is described and the effect of elevated temperature on the growth kinetics shown. Rappaport's medium at 37 degrees C and MKT at either 37 degrees C or 42 degrees C were far superior to selenite F and tetrathionate broth in their selective properties and, with the exception of Rappaport's medium, the use of elevated temperature increased the selectivity of the media.

Culture Media↗
PubMed1984

Local cerebral glucose utilisation in treated and untreated patients with Parkinson's disease.

Using the 18f-fluoro-2-deoxy-d-glucose technique and positron emission tomography (PET), the local cerebral glucose utilisation (1CMRGlc) was measured in four non-demented patients with early-onset, bilateral Parkinson's disease characterised by the predominance of akinesia. The study was done twice, first in the untreated condition, and then after levodopa had been resumed. Despite a marked clinical improvement, we found no alteration in 1CMRGlc between the first and second studies in any of the brain structure analysed. Compared to control values, 1CMRGlc in the basal ganglia was moderately increased in both studies. These essentially negative findings agree with most previous human or animal studies, and indicate that the functional alterations in the central dopaminergic systems of patients with Parkinson's disease have metabolic correlates that are too small to be demonstrated by current PET devices.

Antiparkinson Agents↗