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Biomedical subjects

B Guillot

Publications and source records attributed to B Guillot.

At least 127 records · Page 7Linked to original sources
PubMed1993

Mast cells' contribution to the fibrosing alveolitis of the scleroderma lung.

Fibrosing alveolitis is frequently seen in scleroderma. Although usually causing progressive symptomatology, it may be found in patients reporting no respiratory symptoms. Mast cells may play a role in the pathogenesis of skin fibrosis in scleroderma. We determined the mast cells and other cellular content, as well as measuring the inflammatory mediators in the bronchoalveolar lavage fluid (BALF) in 17 scleroderma patients and nine control subjects to correlate BALF features with fibrosing alveolitis as determined by lung function testing and high-resolution computed tomographic scans. Bronchoalveolar lavage cells were enumerated after May-Giemsa-Grünwald (MGG), alcian blue, and safranine blue staining. Histamine, tryptase, eosinophil cationic protein, hyaluronic acid, and neutrophil-specific myeloperoxidase were measured by radioimmunoassay. In comparison with normal subjects the BALF of scleroderma patients showed an increased percentage of mast cells (p < 0.002, Mann-Whitney U test), and increased levels of histamine (p < 0.005), tryptase (p < 0.02), and hyaluronic acid (p < 0.004). The BALF of the eight scleroderma patients with an abnormal chest X-ray had a significantly greater number of mast cells (p < 0.04, Mann-Whitney U test), and significantly higher levels of histamine (p < 0.03, Mann-Whitney U test) and tryptase (p = 0.02, Mann-Whitney U test) than the nine scleroderma patients with a normal chest X-ray. This study demonstrates the importance of mast cells and mast-cell activation in the pathogenesis of the fibrosing alveolitis of scleroderma.

Adult↗
PubMed1993

[Malignant tumors as complications of lymphedema].

Malignant tumour arising in chronic congenital or acquired lymphedema is a rare medical condition. However it must be well known because of the usual severity of these highly malignant neoplasms. Stewart-Treves angiosarcoma is the most frequent tumour: it is a vascular malignant tumour, which mostly occur in post-surgical or radiotherapeutic lymphedema for breast cancer. It differs from secondary metastasis arising in lymphedema although the clinical and histological appearance is often very close. Other tumours can grow on this ground: Kaposi's sarcoma, squamous cell carcinoma, malignant lymphoma, melanoma. On the pathogenic point of view, many factors converge to this tumoral occurrence: lymphatic stasis and the reorganization of the conjunctival tissue that it will entail, the local immunodeficiency, and also systemic factors as a general immunodeficiency or viral potentially oncogenic infections such as papillomavirus. In practice, the prevention of lymphedema, the regular monitoring of constituted lymphedemas, the hygienic and preventive behaviours of infections are the best arrangements to avoid this tumoral occurrence.

Carcinoma, Squamous Cell↗
PubMed1993

[Phakomatosis pigmento-vascularis. Report of 2 cases associated with angiodysplasia].

Phakomatosis pigmentovascularis is an uncommon disease, with a peculiar association of capillary hemangioma and pigmented lesions. Four entities have to date been described (I to IV), with localized (a) or systematical (b) involvement. In this latter subtype, the cutaneous lesions are associated with visceral (eye, central nervous system) and bony abnormalities. We describe two additional cases of phakomatosis pigmentovascularis type II (b) associated with a Klippel-Trenaunay syndrome. These reports emphasize the frequent occurrence of angiodysplasia of the Klippel-Trenaunay or Sturge-Weber-Krabbe type in the systemic subtype, especially II (b). Accordingly, complete investigations are warranted in all cases, with special attention for bones and some internal organs like eye and central nervous system. Pathophysiological hypothesis for phakomatosis pigmentovascularis are discussed.

Adult↗
PubMed1993

[Carcinomatous degeneration of chronic osteomyelitic fistulae. 4 cases].

The occurrence of epidermoid carcinoma on fistulae of osteomyelitis has been known since the 19th century, and the four cases reported here show that this complication is still present. CASE-REPORTS. Four new cases developed on the tibia 33 to 54 years after the formation of fistulous osteomyelitis are presented here. The patients were three men and one woman, aged from 58 to 78 years. The lesions observed were ulcero-granuloma in three cases and common superficial ulceration in the fourth patient. In two out of four cases the diagnosis was difficult to ascertain and required deep surgical biopsy. The bone was invaded in three cases, but no regional or visceral metastases could be found. All patients were amputated, after failure of conservative radiotherapy in two of them. No recurrence was observed after a 2 to 3 1/2 years' follow-up. DISCUSSION. The frequency of this late complication cannot be measured precisely, but it has been estimated at 0.5 p. 100 of fistulous osteomyelitis. The warning signs are often not specific and delay the diagnosis; they consist of unusual pain, ulceration, granulation and discharge. The diagnosis rests on histology and requires a deep and wide surgical biopsy involving the entire sinus tract, but uncertainties sometimes persist concerning atypical pseudoepitheliomatous hyperplasia. The best treatment is amputation with removal and biopsy of regional lymph nodes when present, but it does not always avoid the occurrence of metastases which appear in 20 p. 100 of the cases, usually during the first three years following diagnosis. CONCLUSION. These four cases exemplify the need to consider this diagnosis in all patients showing changes in an old fistulous osteomyelitis and to confirm it by deep and wide biopsy.

Aged↗
PubMed1993

[Segmental neurofibromatosis].

Segmental neurofibromatosis is a rare form of the disease characterized by the unilateral location of cutaneous neurofibromas and café au lait spots along one or several dermatomes. It corresponds to the fifth type in Riccardi's classification. We report the 83rd case of segmental neurofibromatosis discovered by chance in an 83-year old woman presenting with isolated cutaneous neurofibromas situated on the right T10-L1 dermatomes. Type five neurofibromatosis is divided into four subgroups according to the uni- or bilateral site of the lesions, the presence or absence of a family history and the association, or lack of, with deep regional or systemic lesions. It is usually not hereditary, but due to a post-zygotic somatic mutation in the primary neural crest. The disease has a favourable prognosis: no case of evolution towards generalized neurofibromatosis has ever been reported.

Aged↗
PubMed1993

Comparative study of the efficacy and safety of loratadine syrup and terfenadine suspension in the treatment of chronic allergic skin diseases in a pediatric population.

The safety and efficacy of loratadine (Sch 29851, CAS 79794-75-5) syrup (5 or 10 mg QD) was compared to terfenadine (CAS 50679-08-8) suspension (30 mg b.i.d.) in a randomized, third party blind, parallel-group, multicenter trial. Two hundred thirty-six children ages 6-12 years, with chronic allergic skin disorders were treated for 14 days. The predominant skin condition was atrophic dermatitis (88% of the efficacy population). Evaluation of efficacy was based on investigator and patient assessment of symptoms, overall condition of the disease, and therapeutic response to treatment. After 7 and 14 days of treatment, and in the endpoint analysis (last valid study visit for all patients) the decreases from baseline in mean total sign/symptom scores, and all individual symptoms, did not differ significantly (p > 0.05) between treatments. Itching improved 54% in the loratadine group and 58% in the terfenadine group in the endpoint analysis. Forty-five percent of patients treated with loratadine and 46% of terfenadine-treated patients treated had complete or marked relief of their symptoms at endpoint. The efficacy of loratadine increased during the study, suggesting that patients did not develop tolerance to the medication over the 14-day course of therapy. Mild to moderate treatment-related adverse experiences were reported in 7/113 patients (6%) treated with loratadine and 11/119 patients (9%) treated with terfenadine. Single daily doses of 5 mg or 10 mg loratadine syrup were comparable to terfenadine suspension 30 mg twice daily for improving the symptoms of chronic allergic skin disorders in children. Loratadine was safe and well tolerated.

Child↗
PubMed1993

Controlled trial of azathioprine and plasma exchange in addition to prednisolone in the treatment of bullous pemphigoid.

BACKGROUND AND DESIGN: Bullous pemphigoid is usually treated with systemic corticosteroids. Side effects are common in elderly patients, justifying the search for adjuvant therapy. This randomized, multicentric unblind study was designed to assess the efficacy of azathioprine or plasma exchange when added to conventional doses of prednisolone. One hundred patients with active disease entered the study. They were randomly allocated to receive 28 days of treatment with oral prednisolone sodium metasulfobenzoate (1 mg/kg per day) either alone or in combination with oral azathioprine (100 to 150 mg/d) or four large-volume plasma exchanges. After 28 days, the prednisolone doses were progressively decreased according to the same strict regimen in the three groups (in combination with oral azathioprine in group 2). RESULTS: The clinical results were evaluable in 98 of the 100 patients included in the study. There was no appreciable difference in the percentages of complete remission of the disease in the three therapeutic groups at 28 days (71%, 80%, and 71%, respectively) or at 6 months (42%, 39%, and 29%, respectively). Severe complications were more often observed among patients receiving azathioprine. At 6 months, 14 of 98 patients had died, without any differences noted among the three study groups. CONCLUSIONS: We conclude that neither azathioprine nor plasma exchange is effective enough to be used routinely as an adjuvant to corticosteroids in the management of bullous pemphigoid.

Aged↗
PubMed1993

p53 gene mutations in human epithelial skin cancers.

In the present study we analysed 38 epithelial skin cancers, 19 basal cell carcinomas (BCCs), 13 squamous cell carcinomas (SCCs) and six Bowen diseases (BwDs), using a combination of polymerase chain reaction (PCR) and single-stranded conformation polymorphism (SSCP) techniques for the presence of p53 and RAS gene mutations. Whereas 48% (9/19) of the BCCs tested presented a mutated p53 gene, the frequency was lower (15%, 2/13) in our series of SCCs and negative in the BwDs. Nine of the 11 characterized mutations were single-nucleotide substitutions and, interestingly, seven of these involved CC dimers, where a C was changed into a T or a G (three C-->T transitions and four C-->G transversions). This mutational pattern, added to the fact that all the mutated tumors occurred at sun-exposed body sites, implicates UV light in their genesis. Furthermore, we observed two internal deletions of 6 and 24 bp whose flanking sequences contained two or three Cs on either strand. In addition to molecular detection, we searched for p53 protein accumulation, by immunocytochemical staining, in a subset of 23 epithelial skin tumors (nine bearing a mutation, 14 which scored negative in our assay). Three commercially available anti-p53 antibodies (PAb CM1, mAbs DO7 and 1801) were used, and 3/23 (all showing a mutated p53 gene) presented specific nuclear staining. In contrast to other reported data we could not detect any activating RAS gene mutation in our series of human skin cancers.

Base Sequence↗
PubMed1992

[Carcinoma of the tongue in xeroderma pigmentosum].

Xeroderma pigmentosum (XP) is a rare genodermatosis characterized by a defect in the repair of DNA damage induced by ultraviolet rays. The cutaneous tumours are frequent and occur at an early age, but neoplasias of the mucosae are seldom observed. Among the mucosae, the lipids and the conjunctiva clearly predominate. Tumours of the buccal cavity are much less frequent, and this is why we report a case of epidermoid carcinoma of the tip of the tongue in a Moroccan boy. Only 25 cases of intrabuccal tumour have been reported in patients with XP, and 22 were epidermoid carcinomas of the tip of the tongue. These carcinomas may be preceded by precancerous lesions such as leucoplasia. The early occurrence and elective location at the tip of the tongue clearly differentiate lingual carcinomas associated with XP from their homologues in adults. The aggressiveness of these lesions is difficult to determine due to a usually short follow-up and to the lack of details in reports. Treatment is surgical and non-specific. Concerning epidemiology, the predominance of African and Near-Eastern patients among those suffering from lingual carcinoma is striking. Moreover, when the complementation group is known it is always group C; our patients presented with characteristics of this group. Some authors believe that the lingual tumours are due to ultraviolet light (overexposure in case of natural pigmentation, with exposure of the tip of the tongue) and to certain toxic substances in food.(ABSTRACT TRUNCATED AT 250 WORDS)

Basal Cell Carcinoma↗
PubMed1992

[Role of oncogenes and anti-oncogenes in dermatology].

Cell growth is controlled by two types of genes, i.e., activating genes (oncogenes) and negative regulator genes (antioncogenes). Studies have shown that malignant transformation of a cell can result from either increased oncogene activity or decreased antioncogene activity. Current knowledge of genes relevant to dermatology is discussed.

Animals↗
PubMed1990

Vitamin D metabolism in psoriasis before and after phototherapy.

Epidermis plays a major role in vitamin D synthesis and is a target tissue for 1,25 (OH)2 vitamin D, which could be involved in abnormal proliferation and differentiation of psoriatic keratinocytes. We investigated plasma calcium, phosphorus, alkaline phosphatases, parathyroid hormone, 25 (OH) D, 24,25 (OH)2 D and 1,25 (OH)2 D in 15 control subjects and 20 psoriatic patients before and after 3 weeks of phototherapy (UVB or PUVA). Before irradiation, all parameters were similar in psoriatics and controls, except for serum phosphorus (lower in psoriasis p less than 0.01). After phototherapy, P rose to normal values in psoriatic patients; 25 (OH) D and 24,25 (OH)2 D were dramatically increased by UVB (but not by PUVA) in psoriatic patients as well as in controls; 1,25 (OH)2 D was unmodified in controls but was significantly increased in psoriasis. Since 1,25 (OH)2 D has been reported to be an effective treatment for psoriasis, the UV-induced increase in 1,25 (OH)2 D could account for the beneficial effect of phototherapy in psoriasis.

24,25-Dihydroxyvitamin D 3↗