Search PubMed⌕ Search

Biomedical subjects

B Guillot

Publications and source records attributed to B Guillot.

At least 19 recordsLinked to original sources
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↗
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

Studies of polymorphonuclear migration into psoriatic skin using a new in vivo method.

A new method, employing a skin-implanted cell trap already used to study chemotaxis in cancer patients, was applied to 35 healthy volunteers and 12 psoriatic patients. A dacron disk impregnated with 10 microliters of 4-6.10(6) live BCG suspension was implanted in the deep dermis. After 24 h the disk was removed, and five sections of each disk were counted for polymorphonuclear leukocytes (PMNs) and monocytes. Involved and uninvolved psoriatic skin showed a decrease of PMN migration into the disk as compared with controls. No difference could be demonstrated between involved and uninvolved skin. Mononuclear cell chemotaxis was the same in psoriasis as in controls. These results are in agreement with other in vivo data using mainly the skin chamber technique indicating a decrease of PMN chemotaxis in psoriatic skin at 24 h.

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

[Diabetic cheiroarthropathy].

Cheiroarthropathy is quite frequent in diabetics, but is only really specific at stage III, which is the most characteristic form. It is all the more frequent as the diabetes is old, but remains unrelated to sex, age and type of diabetes. The stiffening of the joint readily extends to other joints. The patients are moderately alerted in the absence of other associated pathologies: trigger finger, Dupuytren's disease, carpal tunnel syndrome. All these manifestations form the "diabetic hand", of which cheiroarthropathy is only one component. The need for an accurate analysis with the purpose of appropriate treatments, should be emphasized. The angiologic and histopathological study of patients with stage III cheiroarthropathy, enables us to demonstrate moderate abnormalities of the microcirculation, which are quite different from those encountered in sclerodermia. The etiopathogenesis of cheiroarthropathy remains mysterious and is probably related to an alteration of the collagen metabolism. One of the most interesting component is the association between cheiroarthropathy and the micro-angiopathic complications of diabetes mellitus: cheiroarthropathy being the indicator of such diabetes.

Adult↗