Comment on "Berry phase correction to electron density of states in solids".
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Biomedical subjects
Publications and source records attributed to C Duval.
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Young French children have 45,000,000 domestic pets, cats and dogs being widely prevalent (40%). Injuries due to domestic animals, especially bites, in particular from dogs, represent 1.9% of all children's injuries. On the quality of first aid in the field, i.e., whether the treatment is the first line in surgical specialized service or not, if it is a vital emergency, will depend the possibility of immediate complications, which include local superinfection (15%), functionals and further aesthetic sequelae. Some injuries due to large animals carry a polytraumatism, which should be treated like all polytraumatisms, whatever the aetiology. Learning to know and respect animals and their needs should remain the priority of families to avoid unexpected injury. Families also need to take charge of the responsible animal.
Peroxisome proliferator-activated receptors (PPARs) are lipid-activated transcription factors belonging to the nuclear receptor superfamily. Three PPAR isotypes have been characterised: alpha, beta/delta and gamma. Identification of selective ligands and gene targeting studies have allowed determination of subtype-specific functions and the therapeutic potential of these receptors. Thus, PPAR alpha plays a prominent role in several physiological processes including the control of lipid and lipoprotein metabolism, glucose homoeostasis and the inflammatory response. Here, we update the potential of PPAR alpha activation in the treatment of metabolic disorders and related cardiovascular complications.
BACKGROUND: Locally advanced and/or inflammatory breast cancer (LABC) is a heterogeneous disease. Molecular markers may help to understand this heterogeneity. This paper reports the results of a study assessing the potential prognostic or predictive value of HER-2, p53, cyclinD1, MIB1, ER and PgR expression by immunohistochemistry from patients included in an EORTC-NCIC-SAKK trial. PATIENTS AND METHODS: A total of 448 patients with a cytological or histological diagnosis of LABC were randomised into a trial comparing two anthracycline-based neoadjuvant regimens. Chemotherapy was followed by standard locoregional therapy. Survival was comparable in both arms. We collected and analysed centrally paraffin-embedded tumour specimens from 187 (72.5%) of 258 patients that had a histological diagnosis. RESULTS: Of the patients included in this molecular marker study 114 relapsed and 91 died. In the multivariate analysis p53 positivity was associated with a shorter progression-free survival [hazard ratio (HR) = 1.96; 95% CI 1.33-2.91; P = 0.0008) and a shorter overall survival (HR = 1.98; 95% CI 1.28-3.06; P = 0.002). PgR positivity predicted for a longer overall survival (HR = 0.54; 95% CI 0.35-0.83; P = 0.0045). CONCLUSIONS: p53 was an independent factor predicting for survival. In order to clarify whether p53 is a pure prognostic and/or a predictive factor, a phase III trial is being conducted (EORTC 10994/BIG 00-01 study) using functional assay in yeast from frozen tumour samples.
Translocations involving the BCL-6 gene are frequently observed in diffuse large B cell lymphoma, but have rarely been reported in follicular lymphoma (FL). We studied a distinct cohort of FLs with a 3q27/BCL-6 gene rearrangement, but lacking the t(14;18) translocation. In 13/15 cases, translocations involved the 3q27 and the 14q32 regions. All cases displayed a marked follicular growth pattern and, in some instances, a monocytoid component. Tumor cells were CD5(-) CD20(+) CD23(-) CD43(-) BCL-6(+), and in the main CD10 negative (n = 10, 71%) and BCL-2 negative (n = 11, 78%). When compared to 20 typical t(14;18)(+) FLs, the presence of large follicles (P = 0.01) and a CD10(-)/BCL-2(-) phenotype were more frequently observed (P = 0.001) in our cohort. Clonal mutations arising in the BCL-6 first intron were observed in 5/7 cases with evidence of intraclonal heterogeneity, consistent with a germinal center origin. No significant difference was found in comparison to t(14;18)(+) FL regarding age, sex, performance status, bone marrow involvement or overall survival. However, in the 3q27(+) FL group, a stage III/IV disease and a bulky mass were less frequently observed. This study indicates that 3q27(+) FL without t(14;18) translocation have peculiar clinico-pathologic features and may correspond to a rare and distinct subtype of lymphoma originating from the germinal center.
Until now, uncoupling protein 1 (UCP1) was considered as unique to brown adipocytes. It supports a highly regulated uncoupling of oxidative phosphorylation that is associated with diet as well as with non-shivering thermogenesis. Here we report that UCP1 is not specific to brown adipocytes and can be expressed in longitudinal smooth muscle layers. In the uterus, this conclusion was drawn from different convergent data. A specific antibody against mouse UCP1 revealed, in mitochondrial fractions, a protein with the same molecular weight as brown fat UCP1. Sensitive and specific reverse transcriptase-polymerase chain reaction detected a mRNA whose sequence was totally homologous to that of brown fat UCP1 mRNA. Antibody against UCP1 as well as a UCP1 antisense probe specifically stained uterine longitudinal smooth muscles. UCP1 was also expressed in longitudinal smooth muscle of digestive and male reproductive tracts but was never expressed in other types of smooth muscle, including those of arterial vessels. In uterine tract, UCP1 content was increased after cold exposure or beta-adrenergic agonist treatment. It was also up-regulated during the postovulatory period after sexual cycle synchronization. Its content transiently increased during gestation and decreased markedly after birth. These regulations strongly argue about a role for UCP1 in thermogenesis as well as in relaxation of longitudinal smooth muscle layers.
PURPOSE: In view of the increasing number of patients treated with breast-conserving treatment (BCT) for ductal carcinoma-in-situ (DCIS), risk factors for recurrence and metastasis should be identified. PATIENTS AND METHODS: Clinical and pathologic characteristics from patients with DCIS in the European Organization for Research and Treatment of Cancer trial 10853 (excision with or without radiotherapy) were related to the risk of recurrence. Pathologic features were derived from a central review of 863 of the 1,010 randomized cases (85%). The median follow-up was 5.4 years. RESULTS: Factors associated with an increased risk of local recurrence in the multivariate analysis were young age (< or = 40 years) (hazard ratio, 2.14; P =.02), symptomatic detection of DCIS (hazard ratio, 1.80; P =.008), growth pattern (solid and cribriform) (hazard ratios, 2.67 and 2.69, respectively; P =.012), involved margins (hazard ratio, 2.07; P =.0008), and treatment by local excision alone (hazard ratio, 1.74; P =.009). The risk of invasive recurrence was not related to the histologic type of DCIS (P =.63), but the risk of distant metastasis was significantly higher in poorly differentiated DCIS compared with well-differentiated DCIS (hazard ratio, 6.57; P =.01). CONCLUSION: Patients with poorly differentiated DCIS have a high risk of distant metastasis after invasive local recurrence. Margin status is the most important factor in the success of BCT for DCIS; additionally, young age and symptomatic detection of DCIS have negative prognostic value.
Size-exclusion chromatography (SEC) is a useful steric separation technique for the analysis of water-soluble polysaccharides in aqueous solution. However, in the case of amphiphilic derivatives, the usefulness is limited because of interactions between hydrophobic segments and the stationary phase. Alkyl-bearing pullulans differing from the extent and the length of alkyl groups were characterized using flow-field flow fractionation with on-line coupling multi-angle laser light scattering (F4/MALLS). Comparison of SEC and F4 is presented and the interest of F4 in the field of amphiphilic derivatives is demonstrated.
The power distribution in the frequency spectrum of tremor is known to vary among individuals and its median power frequency declines with ageing. The purpose of the present study was to determine whether a reduction of the central component of physiological tremor would correlate with a reduction of motor performance. Then, the power distribution in the frequency spectrum of tremor from limb extremities might serve as an index of neural drive in healthy elderly subjects. Rest tremor, postural tremor from the finger, and pronation-supination at the wrist were recorded in 102 healthy nuns living in a convent (mean of 72+/-12 years). Results reveal that several elderly subjects possessed a power distribution of tremor very similar to that of much younger subjects (mean 27 years+/-3 SD), showing a preponderance of power within the 7.6- to 12.5-Hz band. Duration of pronation-supination cycles of these elderly subjects was, however, similar to that of other elderly subjects who had a preponderance of power within the 3.6- to 7.5-Hz band. Consequently, healthy elderly subjects who possessed a predominance of power within higher frequencies were not at an advantage over other healthy elderly subjects when performing a pronation-supination task. The age of subjects was, however, a better predictor or motor performance. In conclusion, the present findings suggest that, under normal physiological conditions, a reduction of the central component of physiological tremor does not induce a reduction of motor performance. Consequently, tremor recorded at limb extremities cannot be used as an index of neural drive.
Striking differences are observed in the melanogenic response of normal human melanocytes to UVA and UVB irradiation depending on culture conditions and the presence of keratinocytes. Exposure of melanocytes co-cultured with keratinocytes to UVB irradiation triggered, already at low doses (5 mJ/cm2), an increase in melanin synthesis whereas in melanocyte mono-cultures, UVB doses up to 50 mJ/cm2 had no melanogenic effect. Unlike UVB, UVA exposure caused the same melanogenic response in both mono- and co-cultures. Removing certain keratinocyte growth factors from the co-culture medium abolished the melanogenic response to UVB, but not to UVA exposure. When integrated into the basal layer of a reconstructed human epidermis, human melanocytes similarly reacted to UVA and UVB irradiation as in vivo by increasing their production and transfer of melanin to the neighboring keratinocytes which resulted in a noticeable tanning of the reconstructed epidermis. The presence of a dense stratum corneum, known to scatter and absorb UV light, is responsible for higher minimal UVB and UVA doses required to trigger a melanogenic response in the reconstructed epidermis compared to keratinocyte-melanocyte co-cultures. Furthermore, an immediate tanning response was observed in the pigmented epidermis following UVA irradiation. From these results we conclude that: (i) keratinocytes play an important role in mediating UVB-induced pigmentation, (ii) UVA-induced pigmentation is the result of a rather direct effect on melanocytes and (iii) reconstructed pigmented epidermis is the most appropriate model to study UV-induced pigmentation in vitro.
We have investigated primary ductal carcinomas in situ (DCIS) of the breast and their local recurrences after breast-conserving therapy (BCT) for histological characteristics and marker expression. Patients who were randomized in the EORTC trial 10853 (wide local excision versus excision plus radiotherapy) and who developed a local recurrence were identified. Histology was reviewed for 116 cases; oestrogen and progesterone receptor status, and HER2/ neu and p53 overexpression were assessed for 71 cases. Comparing the primary DCIS and the invasive or non-invasive recurrence, concordant histology was found in 62%, and identical marker expression in 63%. Although 11% of the recurrences developed at a distance from the primary DCIS, nearly all these showed the same histological and immunohistochemical profile. 5 patients developed well-differentiated DCIS or grade I invasive carcinoma after poorly differentiated DCIS. Although these recurrences occurred in the same quadrant as the primary DCIS, they may be considered as second primary tumours. Only 4 patients developed poorly differentiated DCIS or grade III invasive carcinoma after well differentiated DCIS. We conclude that in most cases the primary DCIS and its local recurrence are related histologically or by marker expression, suggesting that local recurrence usually reflects outgrowth of residual DCIS; progression of well differentiated DCIS towards poorly differentiated DCIS or grade III invasive carcinoma is a non-frequent event.
Peroxisome proliferator-activated receptors (PPARs) are lipid-activated transcription factors that control energy homeostasis through genomic actions. Over the past few years significant advances have been made in unravelling the pathways that are modulated by PPARs. Gene targeting experiments in mice and genetic studies in humans have demonstrated a physiological role for these receptors in adipocyte function, glucose homeostasis, and lipid and lipoprotein metabolism. Recent data indicate that PPARs enhance the reverse cholesterol transport pathway by regulating genes that control macrophage cholesterol efflux, cholesterol transport in plasma and bile acid synthesis. Clinical and experimental evidence suggest that PPAR activation decreases the incidence of cardiovascular disease not only by correcting metabolic disorders, but also through direct actions at the level of the vascular wall. Thus, dysregulation of PPAR activity modulates the onset and evolution of metabolic disorders such as dyslipidaemia, obesity and insulin resistance, predisposing to atherosclerosis.
A 46-year-old patient was referred for a right mammary nodule associated with a chronic mastopathy. Cytological examination suggested an inflammatory process but frozen sections concluded to carcinoma with lymphoid stroma. Histological examination found characteristic features of MALT lymphoma: reactive lymphoid follicles, lymphoplasmocytoid lymphoid proliferation and lymphoepithelial lesions. Immunohistochemistry and in situ hybridation revealed a monotypic IgGk immunoglobulin. Molecular biology techniques found a rearrangement of IgH locus. Lymphocytic perigalactophoritis was found in the remaining breast tissue. After 33 months, no tumoral recurrence occurred. Primary MALT lymphoma of the breast is exceptional and its histogenesis is unclear. The role of pre-existent inflammatory lesions in the genesis of this tumour is not established. Our observation illustrates the diagnostic difficulty and the usefulness of complementary techniques in this diagnosis. The existence of inflammation close to tumour is interesting to emphasize.
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Ventrolateral (VL) thalamotomy produced a marked reduction of oscillations related to the supraspinal components of Parkinson's disease tremor (4-7 Hz) and physiological tremor (8-12 Hz). Finger tremor was examined in nine patients undergoing unilateral VL thalamotomy and in nine age-matched controls. In comparison to the preoperative state, the relative percentage of power within the 7.6-12.5 Hz band did not increase after the surgical procedure. Furthermore, the amount of absolute power within the 7.6-12.5 Hz band was much lower for post-surgical patients in comparison to matched controls when periods of tremor having equal amplitudes were compared. These results suggest that VL thalamotomy interrupts a common circuit involved in the supraspinal component of both physiological and pathological tremors. We provide evidence that the thalamus may be involved in circuits generating physiological tremor in humans.
Data on chromosomal abnormalities in T-cell lymphomas are very rare as compared with those reported in B-cell lymphomas. We performed a cytogenetic study in 71 untreated patients with peripheral T-cell lymphoma, classified according to the criteria of the REAL classification. Fifty-seven patients (80.3%) had abnormal clones, whereas 9 karyotypes (12.7%) showed only normal metaphases; 5 karyotypes (7%) could not be analyzed. Recurrent numerical chromosomal abnormalities comprised +3 (21%), +5 (15.7%), +7 (15.5%), +21 (14%), -13 (14%), +8 (12.2%), +19 (12.2%), -10 (10.5%), and -Y (9% of male patients). Chromosomes involved in structural rearrangements were chromosome 6 (31.5%), mainly due to 6q deletions (19.2%), 1q (22.8%), 7q (22.8%), 9p (19.4%), 9q (19.2%), 4q (19.2%), 3q (19.2%), 2p (17.5%), 1p (17.5%), and 14q (17%). Trisomies 3 and 5 mainly correlated with angioimmunoblastic T-cell lymphoma. Isochromosome 7q, associated with trisomy 8, was present in two cases of hepatosplenic gamma/delta T-cell lymphoma. Rearrangements involving the location of T-cell receptor genes were rarely observed (chromosome band 7q35 was rearranged only in three cases, 14q11 in two cases, and 7p15 in none). No correlation could be found between the cytogenetic findings and histologic subgroup or clinical outcome in these patients. Further studies are needed to understand the significance of these abnormalities in peripheral T-cell lymphoma, and to reach a better evaluation of histologic correlations, as many differences persist between the two major classification systems, KIEL and REAL.
Follicular lymphomas (FL) are closely associated with a t(14;18)(q32;q21) translocation, leading to a bcl2 protein over-production. This translocation probably constitutes a very early step in the development of the disease. Besides the cytogenetic assay, t(14;18) detection can be achieved using either Southern blot or polymerase chain reaction (PCR). Since 1990, several publications have reported discrepancies between the results of cytogenetic and molecular analysis of t(14;18). Using methods able to explore long DNA fragments, several authors reported breakpoints located outside the usual breakpoint regions. However, these techniques cannot be easily used in routine. The aim of this study was to develop a simple PCR assay to amplify rearrangements usually not detected in FL. We selected a group of 83 patients with a t(14;18) on cytogenetic analysis: using usual probes and primers, 54/83 (65.1%) showed a MBR rearrangement, 7/83 (8.4%) were mcr positive and 22/83 (26.5%) remained negative. Among these 22 rearrangements, nine could be detected using this new PCR assay. Four breakpoints were located in a 20 bp area suggesting a recurrent breakpoint cluster close to an Alu repetitive sequence. Finally, remaining negative cases (13/83, 15.6%) suggest that other breakpoints are located between the MBR and mcr regions.
The t(14;18)(q32;q21) translocation is the most common translocation in B cell malignancies being found in 80% of follicular lymphomas and about 20% of diffuse large B cell lymphomas. Only rare cases of de novo acute B cell lymphoblastic leukemia with t(14;18) have been described. We describe five cases of this entity which appears to have very homogeneous clinical, phenotypic and genotypic features. None of these patients had prior history of follicular lymphoma. The disease was characterized by acute clinical features with nodal and/or extranodal disease, massive bone marrow infiltration and rapid increase of circulating blast cells of mature B cell phenotype. All patients disclosed complex chromosomal and molecular abnormalities involving at least the BCL-2 and c-MYC genes. Furthermore, three patients had evidence of BCL-6 involvement and one patient had a p53 mutation. Despite intensive chemotherapy, including for two patients allogeneic bone marrow transplantation in first complete remission, all patients died within a few months. Neuro-meningeal relapse occurred in three of the five patients in spite of neuro-meningeal prophylaxis. De novo leukemia/lymphoma with t(14;18) is a rare entity with a very poor prognosis. Whether early bone marrow transplant could modify the natural history of the disease remains to be determined. An intensive neuro-meningeal prophylaxis appears to be mandatory in these patients.