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Biomedical subjects

P Bernard

Publications and source records attributed to P Bernard.

At least 55 records · Page 3Linked to original sources

Lichen sclerosus is frequently present in penile squamous cell carcinomas but is not always associated with oncogenic human papillomavirus.

BACKGROUND: Penile squamous cell carcinoma (SCC) may occur on pre-existing lesions of lichen sclerosus (LS). However, the prevalence of histological changes of LS in penile SCC is not well established. Moreover, mucosal oncogenic human papillomaviruses (HPVs) are sometimes detected in penile SCC, but have not been systematically sought in LS-associated penile SCC. OBJECTIVES: To establish the prevalence of LS histological changes and of mucosal oncogenic HPV in a series of patients with penile SCC. METHODS: Consecutive cases of histologically proven penile SCC from a single university hospital over a 14-year period were retrospectively selected and reviewed. Histological signs of LS were systematically sought. HPV was detected by polymerase chain reaction (PCR) amplification of DNA from paraffin-embedded skin samples using general primers GP5+/GP6+ (allowing detection of mucosal HPV) and oncogenic type 16-, 18-, 31- and 33-specific primers. RESULTS: Eighteen cases of penile SCC were found. The mean +/- SD age of patients at diagnosis was 67.3 (14.5 years). In eight of 18 (44%) cases, SCC was associated with histological features of LS. Seventeen skin biopsy specimens of SCC (nine without and eight with LS histology) were subjected to PCR amplification for HPV. Mucosal HPV was detected in six of them (35%). Five of nine SCCs without histological features of LS were positive for mucosal HPV: three with HPV type 16 and two with only general primers. In contrast, all eight SCCs associated with LS were negative for oncogenic HPV types, although one was positive with general primers. CONCLUSIONS: Penile SCC seems to be frequently associated with LS histological changes. As with vulval SCC, we found that non-LS-associated penile SCC tended to be frequently associated with oncogenic HPV infection, whereas LS-associated penile SCC was not. Larger series are needed to confirm this association.

Adult↗

[Haemorrhagic cellulitis: three cases].

BACKGROUND: Haemorrhagic erysipelas (cellulitis) is a recently described clinical condition. We report 3 new cases of this rare bacterial dermatosis requiring both antibiotics and systemic corticosteroids for complete resolution. CASE REPORTS: Case 1 was a 75 year-old male patient, with a past history of hypertension and diabetes mellitus. Case 2 was a 69 year-old female patient with a past history of hepatic cirrhosis. Case 3 was a 56 year-old female patient without medical past history, except for obesity. All patients presented with a haemorrhagic and bullous erysipelas of the leg without clinical improvement under parenteral antibiotics. In all cases, adjuvant systemic corticosteroids (prednisone: 0.5 mg/kg/d) for 5-8 days in addition to antibiotics provided dramatic and complete resolution of skin lesions and disappearance of pain and fever. DISCUSSION: Haemorrhagic cellulitis may be misdiagnosed as necrotizing fasciitis because of ecchymotic areas with frequent bullae resulting in haemorrhagic crusts and partial inefficacy of antibiotics given alone. Adjuvant anticoagulant therapy or coagulation abnormalities may have facilitated the clinical condition in 2 of our 3 cases. The efficacy of adjuvant systemic corticosteroids during 5-8 days, in addition to antibiotics is the hallmark of this syndrome.

Aged↗

[Non infectious skin conditions associated with diabetes mellitus: a prospective study of 308 cases].

INTRODUCTION: Non-infectious dermatoses during diabetes appear frequent if one refers to some of the studies in the literature that have attempted to assess its prevalence. PATIENTS AND METHODS: From November 2000 to November 2001, 308 randomly selected, hospitalized, diabetic patients were examined. The data were collected prospectively and systematically in a pre-established questionnaire. Statistical analysis included a descriptive and univariate analysis. RESULTS: 206/308 diabetics (67 p. 100) exhibited at least one non-infectious dermatitis, the most frequent of which was cutaneous xerosis (39 p. 100), diabetic dermopathy (24 p. 100), facial erythrosis (24 p. 100), purpural and pigmented capillaritis of the legs (20 p. 100), xanthochromia (12 p. 100) pseudo-scleroderma (8 p. 100) and acanthosis nigricans (7 p. 100). The non-infectious dermatoses were globally more frequent in type II diabetic patients exhibiting at least one microvascular complication. DISCUSSION: This study is the first French prospective work on the subject. We found a prevalence of non-infectious dermatoses during diabetes close to that of the major studies in the literature. Some of these dermatoses are markers of macrovascular (acanthosis nigricans, purpural and pigmented capillarity) or microvascular (xerosis, acanthosis nigricans, purpural and pigmented capillarity, Dupuytren's disease) complications for type II diabetes or are markers of auto-immunity (alopecia areata, vitiligo) for type I.

Adult↗

[Techniques, indications and early results of splenic preservation during left pancreatectomy].

STUDY AIM: Splenic preservation is rarely performed during left pancreatectomy. We compared retrospectively the early results of left pancreatectomy with and without splenic preservation to define the place of this procedure. PATIENTS AND METHODS: From 1979 to 1997, among 54 left pancreatectomies for another indication than adenocarcinoma, 13 were performed with and 41 without splenic preservation. The technique used for splenic preservation was prograde dissection of the left pancreas with (n = 4) and without (n = 9) preservation of both splenic artery and vein. The preoperative characteristics of the patients, peroperative data, postoperative morbidity and length of stay were compared. RESULTS: Mean operative time was longer with splenic preservation (262 +/- 67 min versus 215.6 +/- 59 min, p < 0.05), particularly in case of splenic vessels preservation (295 +/- 38 min, p < 0.02) whereas no difference was noted with splenic vessels ligation (240 +/- 76 min, p > 0.05). No mortality occurred. Prevalence of preoperative or postoperative haemorrhage, morbidity, or length of stay (intensive care unit and whole hospitalisation) did not differ with or without splenic preservation. Five patients developed pancreatic fistula without influence of splenic preservation: 1/13 (7.7%) versus 4/41 (9.7%); conversely, surgery following acute pancreatitis was associated with an higher risk of pancreatic fistula: 3/5 versus 2/49 (p < 0.005). No splenic necrosis occurred after splenic preservation. CONCLUSION: During left pancreatectomy, splenic preservation increases the operative duration (only in case of preservation of splenic vessels) but does not increase morbidity. This technique should be used whenever possible to allow long term immunological benefits of splenic preservation.

Acute Disease↗

Preliminary screening of some tropical plants for anti-tyrosinase activity.

In our efforts to find new active tyrosinase inhibitors for skin-whitening or antibrowning preparations, we investigated 67 tropical plants belonging to 38 families, which were evaluated for their anti-tyrosinase activity. The results of our investigation show that extracts of 5 plants, Stryphnodendron barbatimao, Portulaca pilosa, Cariniana brasiliensis, Entada africana and Prosopis africana present interesting in vitro mushroom tyrosinase inhibition (over 90%), similar to a positive control: Morus alba. These 5 plants will be studied in order to isolate and identify phytochemical compounds, involved in this biological activity.

Agaricales↗

[Hospitalization criteria for erysipelas: prospective study in 145 cases].

INTRODUCTION: Two recent studies conducted in France among general practitioners have shown that they only hospitalized between 20 to 50 percent of patients with erysipelas seen in private practice. We therefore conducted a hospital-based, prospective study designed to determine the hospitalization criteria for erysipelas, since a number of patients are also hospitalized directly through the emergency department. PATIENTS AND METHODS: This prospective, hospital-based study, included patients hospitalized for clinical diagnosis of erysipelas in 9 centres in north-eastern France. Clinical data were recorded using a standard questionnaire filled-in during the first 72 hours of hospitalization. They included: demographic (name and first name initials, age, sex) and clinical (location of erysipelas) characteristics, as well as the origin of the patient (home, emergency department, other department), the reasons for hospitalization (severity of local or systemic signs, suspicion of deep vein thrombosis, location on the face, age over 60 years, associated diseases, absence of improvement after ambulatory treatment, socioeconomic reasons or on principle hospitalization). Patients hospitalized by (or without) a general practitioner were compared using Chi-2 and Student t tests. RESULTS: One hundred forty-five adults (80 women and 65 men; mean age 61 +/- 20 years) were included in the study: 89 patients (61 p. 100) were hospitalized by a general practitioner whereas 56 (39 percent) went directly to the emergency department. In 128/145 cases (88 p. 100), erysipelas was localized on the lower limbs. The mean number of reasons for hospitalization per patient was of 2.2 +/- 1.2. The most frequent reason for hospitalization was an associated disease (diabetes, obesity, alcoholism, immunodeficiency), present in 77 cases (53 p. 100). Patients hospitalized through a general practitioner were older than those hospitalized directly through the emergency department (68 vs 51 years; p<0.001). Patients hospitalized by a general practitioner more frequently had an erysipelas located on the lower limbs (94 p. 100 vs 79 p. 100; p<0.001) and the mean number of reasons for hospitalization was greater (2.4 vs 1.7; p<0.001), especially suspicion of deep vein thrombosis and elevated mean age. The treatment started during hospitalization was intravenous penicillin G in 67 cases (46 p. 100), oral pristinamycin in 28 cases (19 p. 100) and intravenous or oral amoxicillin in 9 cases (6 p. 100). COMMENTS: This study demonstrates the existence of two distinct courses of hospitalization for erysipelas. Patients hospitalized by a general practitioner were older and their erysipelas more frequently located on the lower limbs and deep vein thrombosis was suspected. Our study also shows the emergence of a population of patients younger and without medical supervision, for whom the general practitioner is replaced by the emergency department of the local hospital. Nevertheless, the most frequent reason for hospitalization in both groups is the existence of an associated disease, possibly responsible for further complications.

Adult↗

[Malignant blue nevus: clinicopathologic study with AgNOR measurement. Seven cases].

BACKGROUND: Malignant blue nevus is a very rare tumor. Argyrophilic nucleolar organizer regions (AgNORs) have been reported to be both a diagnostic and prognostic clue in various tumors, especially if standardized using an image analysis systems. PATIENTS AND METHODS: Seven cases of malignant blue nevus were retrospectively recorded between 1974 and 1999, and their clinical and pathological features described. Using an image analysis system, AgNOR measurements were studied in all cases. These results were compared with those obtained in 10 cases of commun blue nevus, 10 cases of cellular blue nevus and 10 cases of malignant melanoma. RESULTS: The most frequent location of malignant blue nevus was the scalp. Clinically, the tumor generally consisted of a blue nodule, 2.5 cm in diameter. There was no single histopathological criterion for the diagnosis of malignant blue nevus. AgNOR measurement was significantly higher in malignant blue nevus in comparison with commun blue nevus (p<0.0004) or cellular blue nevus (p<0.012), whereas there was no difference between malignant blue naevus and malignant melanoma (p > 0.50). DISCUSSION: Our results confirm the severe prognosis of malignant blue nevus and highlight the necessity of removing all blue tumours located on the scalp. AgNOR measurement using an image analysis system appears to be a useful tool for the diagnosis of malignant blue nevus, but further studies remain necessary.

Adolescent↗

[Positive photobiological investigation in Jessner's lymphocytic infiltration of the skin].

BACKGROUND: Jessner's lymphocytic infiltration of the skin is a rare and benign disorder. Its clinical course is cyclic with remissions and exacerbations. In this disease, photosensitivity was previously noticed by authors and recently demonstrated. We report four new cases with positive photobiological investigation. CASE REPORTS: Four patients (2 males, 2 females), with a mean age 36 years were seen with erythematous papules or discoid plaques on face, arms and upper trunk. The onset of disease occurred after sun exposure in summer. Skin biopsies showed perivascular lymphocytic infiltration in the dermis. All patients relapsed cyclically with incomplete healing during winter. Photobiological investigation elicited skin lesions in a broad spectrum of UV: UVB (2 cases), UVA (1 case), UVA and UVB (1 case). In all patients treatment with oral antimalarials and external photoprotection was effective. DISCUSSION: Our data suggest that photosensitivity history in patients with Jessner's lymphocytic infiltration of the skin should be searched for, and confirmed by provocative phototesting. This relevant event could guide the therapeutic strategy because antimalarials were effective for the Jessner's lymphocytic infiltration cases with photosensitivity.

Adult↗

Cumulative influence of matrix metalloproteinase-1 and -2 in the migration of melanoma cells within three-dimensional type I collagen lattices.

During melanoma progression, migrating cells must cross human dermis, a type I collagen-rich tissue. We have show that MMP-1 and MMP-2 act in a cumulative manner in the in vitro invasion of a three-dimensional type I collagen matrix by melanoma cells. Two melanoma cell lines (M1Dor and M3Da) previously reported to secrete proMMP-2 in a direct relationship with their tumorigenic potential into nude mice were used (F. Capon et al., 1999, Clin. Exp. Metastasis 17, 463-469). The highly tumorigenic cell line (M3Da) displayed a five-fold faster migration rate in type I collagen matrix, compared to its lower tumorigenic counterpart (M1Dor). In parallel, activation of proMMP-2 was evidenced in M3Da- but not M1Dor-populated collagen lattices. Such enzyme activation was associated with a significant decrease in TIMP-2 and TIMP-1 production. Agents known to interfere with proMMP-2 activation, i.e., excess TIMP-2, furin convertase inhibitor, and alphavbeta3 blocking antibody, reduced by 30-40% the type I collagen invasive capacity of M3Da cells. By comparison, batimastat, a wide-spectrum MMP inhibitor, exhibited a more pronounced inhibitory effect (>70%). It suggested that other collagenases than MMP-2 could participate in type I collagen invasion. Collagenase-3 (MMP-13) was produced at low levels by melanoma cells whatever the cell culture conditions. In contrast, M3Da and M1Dor cells secreted collagenase-1 (MMP-1) following 48 h of culture on plastic dishes. Growing melanoma cells in type I collagen gel did not modify enzyme production, but induced proMMP-1 activation in M3Da but not M1Dor cell-populated lattices. Blocking the plasmin-mediated proMMP-1 activation by aprotinin inhibited type I collagen gel invasion by 30%. Since the combination of aprotinin and furin convertase inhibitor reduced collagen invasiveness by melanoma cells to a level comparable to that attained with batimastat, we conclude that both MMP-2 and MMP-1 are involved in such tissue invasion.

Animals↗

Requirement of heterochromatin for cohesion at centromeres.

Centromeres are heterochromatic in many organisms, but the mitotic function of this silent chromatin remains unknown. During cell division, newly replicated sister chromatids must cohere until anaphase when Scc1/Rad21-mediated cohesion is destroyed. In metazoans, chromosome arm cohesins dissociate during prophase, leaving centromeres as the only linkage before anaphase. It is not known what distinguishes centromere cohesion from arm cohesion. Fission yeast Swi6 (a Heterochromatin protein 1 counterpart) is a component of silent heterochromatin. Here we show that this heterochromatin is specifically required for cohesion between sister centromeres. Swi6 is required for association of Rad21-cohesin with centromeres but not along chromosome arms and, thus, acts to distinguish centromere from arm cohesion. Therefore, one function of centromeric heterochromatin is to attract cohesin, thereby ensuring sister centromere cohesion and proper chromosome segregation.

Cell Cycle Proteins↗

Rat olfactory bulb and epithelium UDP-glucuronosyltransferase 2A1 (UGT2A1) expression: in situ mRNA localization and quantitative analysis.

UDP-glucuronosyltransferases (UGTs) form a multigenic family of enzymes involved in the biotransformation and elimination of numerous endo- and xenobiotic compounds. Beside the diverse UGT isoforms present in the liver as well as in other tissues, the UGT2A1 isoform, also called olfactory UGT, was initially thought to be expressed in the nasal epithelium only. In this work, we demonstrate the UGT2A1 mRNA expression in the olfactory bulb, using in situ hybridization and quantitative reverse transcription-polymerase chain reaction (RT-PCR) techniques. Within the epithelium, UGT2A1 mRNA is mainly found in the sustentacular cells and to a lesser extent in Bowman's gland cells. Moreover, in situ hybrization staining reveals UGT2A1 mRNA expression in the olfactory sensory neuron nuclei. Neuronal localization of UGT2A1 mRNA within the olfactory bulb is mainly found in the deeper granular cells. The development of the quantitative multistandard RT-PCR method firstly required characterization of the mouse Ugt2A1 cDNA by rapid amplification of cDNA ends (RACE)-PCR. UGT2A1 mRNA levels appear quantitatively six-fold lower in the olfactory bulb than in the epithelium, in both the rat and mouse. The expression of UGT2A1 in the olfactory bulb, which directly connects the nasal epithelium to the brain, emphasizes the potential role of this enzyme in the protection of the brain against airborne hazardous chemicals.

Air Pollutants↗

Molecular modeling of the GABA/GABA(B) receptor complex.

A three-dimensional model of the extracellular domain of the GABA(B) receptor has been built by homology with the leucine/isoleucine/valine-binding protein. The complete putative GABA-binding site in the extracellular domain is described in both the open and closed states. The dynamics of the "Venus flytrap" mechanism has been studied, suggesting that the molecular dipole moments play a key role in GABA binding and receptor activation. Important residues putatively implicated either in ligand binding or in the dynamics of the receptor are pinpointed, thus highlighting target residues for mutagenesis experiments and model validation.

Amino Acid Sequence↗