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Biomedical subjects

G Barneon

Publications and source records attributed to G Barneon.

At least 19 recordsLinked to original sources
PubMed1992

[Neuroblastoma, factor of early decompensation of tetralogy of Fallot].

The authors report the case of a tetralogy of Fallot associated with a neuroblastoma secreting large quantities of noradrenaline. Anoxic decompensation of the tetralogy of Fallot occurred early at the age of 4 months with cyanotic crises associated with an impression of abdominal pain. A systemic-pulmonary anastomosis was performed and the cyanosis regressed but the crises persisted and investigations showed the presence of a neuroblastoma. The tumour was treated by surgery and chemotherapy and has not recurred after 2 years' follow-up. Complete repair of the tetralogy of Fallot was performed secondarily at the age of 2. In this case, the high concentration of circulating catecholamines was probably a factor of early decompensation of the tetralogy of Fallot by infundibular spasm. A review of the literature revealed 26 cases of cardiac disease with a peripheral neurogenic tumour. Two pathogenic mechanisms are suggested: an embryological abnormality of cardiac cell migration from the neural crest and chronic stimulation of neuroblastic cells by chronic hypoxia.

Humans↗
PubMed1991

Skin test reactivity in patients suffering from lung and breast cancer.

Mast cells and histamine-mediated reactions may be altered in patients with cancer. In an attempt to characterize the possible skin defects in patients with cancer, we tested 22 patients suffering from lung cancers, 30 from breast cancers, and 30 age-matched normal individuals, using several compounds, in investigating the pathophysiology of the skin response. Histamine hydrochloride (10 and 100 mg/ml) and codeine phosphate (9%) were tested by prick test. Substance P (50 and 500 ng per injection site), phentolamine (20 micrograms per injection site), and carbachol (1 microgram per injection site) were tested by intradermal skin tests. Skin mast cells were also microscopically examined in 10 patients with lung cancer, five with breast cancer, and 10 normal subjects. The mean wheal sizes induced by all the tested substances were similar in patients with cancer and chronic bronchitis and in normal individuals. The flare to histamine, codeine phosphate, and substance P was completely abolished in 7/22 patients with lung cancer, but the lack of flare was not related to the age of the patients, nor to the staging of cancer, nor to metastasis. The mean numbers of alcian blue-stained or toluidine blue-stained positive mast cells were similar in normal subjects and in subjects with cancer. This study does not confirm the skin hyporeactivity of patients with cancer.

Adult↗
PubMed1991

Increased numbers of hypodense alveolar macrophages in patients with bronchial asthma.

Alveolar macrophages (AM) are among the cells involved in the bronchial inflammation of asthma. It has been shown that AM are a heterogeneous cell population in normal subjects. The heterogeneity of AM from 36 asthmatic patients and 23 normal subjects was studied using Percoll density fractionation. AM recovered from asthmatic patients are mainly in the lower density fractions (1.03 and 1.04 g/ml), whereas AM from normal subjects are in the higher density fractions (1.05 and 1.07 g/ml). Electron microscopic studies showed that low density AM of both asthmatic and normal subjects appear to have morphologic characteristics of activated cells by comparison with high density AM that present characteristics of quiescent cells in both asthmatic and normal subjects. The functional activity of AM fractions of asthmatic and control subjects was assessed using the release of the oxygen free radicals induced by opsonized zymosan and TxB2 generation by A23187. There was no difference between the five fractions of asthmatic or control subjects with regard to oxygen species release. The TxB2 generation was increased in the low density AM from asthmatics when compared with the same fractions of normal subjects. The hypodense cells produced less TxB2 than did cells of higher density in both asthmatic and normal subjects. The density of AM was correlated with the recent instability of the asthma but not with the severity of it. This study shows that AM from asthmatic subjects, when compared with those from control subjects, are heterogeneous, hypodense cells and that they predominate. Hypodense AM did not appear to be hyperresponsive in vitro and may have been already committed into the airways.

Adolescent↗
PubMed1991

[Effects of ultrasonic aspiration on the sciatic nerve of rats. Experimental study].

We report the effects of induced ultrasonic lesions on the sciatic nerve of the rat. Using different level of intensity (5 to 35%) and time exposure (5 to 60 seconds) for each application, we study the effects by action potential recording, microphotography and histological study. The nerve remains unaltered for low intensity (5 to 10%) until a time exposure of 20 seconds. Beyond that level, a progressive severity of the lesion is documented from oedema to contusion. A safe use of the surgical ultrasonic aspiration in the vicinity of nerves and roots must have a low intensity level, reducing the risks of direct contact between nerve and sonoprobe.

Action Potentials↗
PubMed1990

Intrahepatic bile duct cystadenocarcinoma: case report and imaging diagnosis.

The authors report the 30th case in the literature of cystadenocarcinoma of the liver and the second case arising in the caudate lobe. This case illustrates the 2 main questions raised by this tumor: the importance of differentiating benign and malignant cystadenoma and bile duct cyst on sonographic and scanographic aspects and the surgical management of these tumors of the liver, especially in this malignant centrohepatic case.

Bile Duct Neoplasms↗
PubMed1990

[Cutaneous lesions in POEMS syndrome. Apropos of 3 case reports and a review of the literature].

We present three new cases of POEMS syndrome with the most common cutaneous signs of this entity. The syndrome is a multivisceral complex, mostly described in Japanese patients, which includes polyneuropathy, organomegaly, endocrine disorders, monoclonal gammopathy and skin changes. The latter are constant but sometimes reduced to one type of lesion. The most frequent are hyperpigmentation sparing the mucosae, hypertrichosis, scleroderma-like skin thickening and capillary angiomas. The other signs are much less common, as shown in table I. Histological findings are seldom reported and usually have little specificity. None of these abnormalities is pathognomonic, but their predominance at the extremities may be suggestive and leads to a search for other elements of the syndrome, notably gammopathy. The main differential diagnostic problem is with scleroderma, sometimes circumscribed and often systemic. Some cases are very ambiguous. The relationship between the two diseases would suggest the existence of one or several common pathogenic factors. The overall physiopathology of POEMS syndrome is obscure. The role of endocrine disorders in the genesis of the cutaneous signs is subject to discussion: hyperoestrogenism may explain some of these signs, but hypertrichosis is incompatible with the frequent finding of low androgen secretion. The role of one or several "toxic" substances secreted by plasmocytes is highly hypothetical. In some cases, the skin abnormalities have regressed after treatment of gammopathy, and in rare patients the recurrence of gammopathy was followed by that of skin lesions. In a few cases, a "paraneoplastic" character may be suspected.

Adult↗
PubMed1990

[Diabetic cheiroarthropathy. Microcirculatory aspects].

Diabetic cheiroarthropathy (DCA) or pseudosclerodermatous hand of the diabetic is characterized by nonpainful limited extension of the proximal metacarpophalangeal and/or interphalangeal joints with spontaneous flexum of the fingers. The mechanism of lesion formation is poorly known but apparently associates neurogenic, vascular and cutaneous phenomena. Fifteen patients with DCA (9 men, 6 women; range 20-74 years) were studied by capillaroscopy, photoplethysmography and skin biopsy. Eleven had type 1 diabetes and 4 type 2 over periods ranging from 1 to 42 years (mean 19.9 years). Diabetic retinopathy was noted 10/15 times, nephropathy 5/15 times and neuropathy of the lower limbs 13/15 times. All patients had at least one of these abnormalities. In capillaroscopy, "Shoal of fish" features of diabetic microangiopathy were found only 4 times, but minor dystrophy was noted in 12 cases. In digital photoplethysmography, a drop in digital systolic pressure or an increase in pulse time was noted in 5 cases. The Hillestad test was less than or equal to 2 in 8 patients. Histological study showed constant dermal collagenous fibrosis in diseased skin, which was also found in normal skin in 6/13 patients. PAS staining showed a thickening of vascular basal membrane 14/15 times in diseased skin and 11/13 times in normal skin. The relation between DCA and microangiopathy is discussed in terms of collagen metabolism abnormalities observed during diabetes.

Adult↗
PubMed1989

Pemphigus associated with Castelman's pseudolymphoma.

Several cases of association between pemphigus vulgaris and Castleman's pseudolymphoma have been reported. We describe a new case with mucocutaneous involvement and improvement after tumor removal. A review of the literature is presented.

Adolescent↗
PubMed1989

[Should the development of virological diagnostic methods influence our practical approach?].

Respiratory viral infections which occur in patients with spontaneous or therapeutic immunodepression are frequent and serious. Apart from these acute situations, viruses are responsible for some chronic respiratory pathologies which affect the functional prognosis, as illustrated by the relationship between the respiratory pathologies demands an accurate diagnosis. Two methods can be used routinely to demonstrate the presence of a virus in bronchoalveolar lavage fluid or in transbronchial biopsy: (1) direct immunofluorescence or immunoenzymatic technique; the concomitant finding of a cytopathogenic effect on the cells that constitute the sample makes this method more sensitive and confirms the pathogenic character of viruses demonstrated by immunological techniques; (2) isolation of the virus from cell cultures; the sensitivity of this method can be increased by an immunological search for the virus (fast culture). Hybridization in situ is a new and promising method where a DNA probe complementary to viral nucleic acids is used to evidence the viral genome in the infected cells. Serum IgM assays, which provide proof of an active infection, should be preferred to conventional serology, although seroconversion is inconstant in immunodepressed patients. Improvements in virological diagnostic methods should result in the future use of new antiviral treatments.

Biopsy↗