Resistive Index or color-Doppler semi-quantitative evaluation of renal perfusion by inexperienced physicians: results of a pilot study.

BACKGROUND: Doppler-based renal resistive index (RI) calculation may help in the early detection of acute kidney injury (AKI). Its feasibility and reproducibility by inexperienced operators remain unknown. The main objective of this study was to compare performances of junior and senior operators in assessing renal perfusion using both the semiquantitative color-Doppler scale and RI calculation. METHODS: Prospective cohort study performed in 3 ICUs. Inexperienced juniors physicians attended a half-day course on renal perfusion assessment using RI calculation and color-Doppler (from 0, absence of renal perfusion; to 3, renal vessels identifiable in the entire field of view). Junior and senior operators used both methods in 69 mechanically ventilated patients, in blind fashion. RESULTS: Failure to obtain RI occurred for a junior operator in a single patient. RI and color-Doppler semi-quantitative values obtained by operators were correlated (r²=0.64 and r²=0.61, respectively). Systematic bias across operators as assessed using Bland-Altman plots was negligible (-0.001 and -0.29, respectively), although precision was limited (95% confidence intervals, +0.105 to -0.107 and +0.98 to -1.04, respectively). RI calculation and semi-quantitative assessment performed well for diagnosing persistent AKI (area under the receiver-operating characteristic curve, 0.84 [95% confidence interval, 0.73-0.97] and 0.87 [0.77-0.97], respectively). CONCLUSION: A brief course on renal Doppler allowed inexperienced operators to assess effectively renal perfusion with a good reliability when compared to senior operators. In addition, our results suggest the good diagnostic performance of both Doppler-based RI and semi-quantitative renal perfusion assessment in predicting short-term renal dysfunction reversibility.

Tantalum oxide/carbon nanotubes composite coatings on titanium, and their functionalization with organophosphonic molecular films: a high quality scaffold for hydroxyapatite growth.

Nowadays, titanium is a very commonly used biomaterial for the preparation of orthopedic and dental implants. Its excellent mechanical and biochemical bulk properties are nevertheless counterbalanced by its propensity to long term degradation in physiological conditions and its weak osseointegrative capacities. In this context, surface modifications can significantly hinder titanium weaknesses. The approach considered in this work relies on the preparation of thin composite coatings based on tantalum oxide and carbon nanotubes by sol-gel process. Tantalum is particularly interesting for its high biocompatibility and bioactivity, as well as its strong resistance to bio-corrosion. Carbon nanotubes are exploited to reinforce the compactness and homogeneity of the coatings, and can act as a favorable factor to strengthen the interaction with bone components by biomimicry. The composite layers are further modified with specific organophosphonic acid molecular films, able to chemically bind the tantalum oxide surface and improve the hydroxyapatite formation process. The characteristics and the qualities of these hybrid inorganic/organic coatings are evaluated by XPS, SEM, TEM, peeling tests, contact angle measurements, and electrochemical characterizations (free potential, polarization curves).

Expression of the chemokine receptor CCR6 in the Lewis lung carcinoma (LLC) cell line reduces its metastatic potential in vivo.

Chemokines and their receptors play important roles in various aspects of tumoral processes, and evidence was provided for their critical involvement in determining the metastatic destination of tumor cells. Here, we analyzed in vitro and in vivo, how CCR6 expression could alter the behavior of Lewis lung carcinoma (LLC) cells, which were shown to express low levels of the CCR6 ligand, CCL20 (LARC), both in vitro and in vivo. The expression of CCR6 significantly decreased the number of metastases in immunocompetent C57BL/6 mice, without affecting the tumor-forming ability of LLC cells. This was correlated with a decrease in clonogenicity in soft and hard agar, and with increased adhesion to type-IV collagen. These two observations made in basal conditions were enhanced when CCL20 was added to the assay medium. Thus, expression of CCR6 in tumor cells, associated with the local production of CCL20, decreased the metastatic potential of the LLC line. We propose a model, in which the expression of a chemokine receptor in tumor cells can act as a metastasis-suppressor, or a metastasis-promoting factor, according to the expression, or the absence of expression of the cognate ligand(s) in the tumor.

[Newcastle disease in southern Chad: peak epidemic periods and the impact of vaccination]. / La maladie de Newcastle au sud du Tchad: périodes de pic épidémique et impact de la vaccination.

In spite of its universally acknowledged importance, backyard chicken production is still being hampered by Newcastle disease in some parts of the world. In Chad, the disease has been reported almost everywhere in the country and confirmed in several regions, but there are no control measures in place. A survey was conducted at three sites in south-eastern Chad in July and August 2001, based on face-to-face interviews with 20% of the peasant farmers keeping chickens at these sites. The aim was to collect information on peak epidemic periods and on ways in which the infection spreads. The survey revealed that the peak epidemic periods for Newcastle disease are April, during the mango harvesting and selling period, and December, when trade increases for the seasonal festivities. The survey also showed that peasant farmers attach great importance to chicken farming. The survey was followed by a vaccination trial in November 2001 and February 2002, using the La Sota strain administered ocularly. All of the birds vaccinated during the trial were successfully protected from the disease and both chicken production and the income of the villagers increased. The authors conclude that in order to sustain poultry farming and maximise production in the southern zone, vaccination programmes must be urgently introduced, campaigns to raise awareness of Newcastle disease should be carried out and financial support to pay for vaccines should be provided. Efforts to combat other causes of poultry mortality must also be undertaken.

CXCR4 expression in vitreoretinal membranes.

BACKGROUND/AIM: Proliferative vitreoretinopathy (PVR) and macular pucker (MP) vitreoretinal membranes are caused by abnormal cell migration. By their role in chemotactism, chemokine receptors represent good candidates to sustain this process. The authors thus investigated the expression of one of them, CXCR4, in these pathologies. METHODS: Three PVR and four MP membranes were surgically removed and processed for immunochemical studies with antibodies for CXCR4, cytokeratins or smooth muscle actin. RESULTS: CXCR4 expression was found in all membranes. There was no relation between severity of PVR or MP and presence of CXCR4. In addition, there was no difference in CXCR4 expression between MP and PVR. CONCLUSION: CXCR4 is expressed in PVR and MP. Further experiments are needed to test if CXCR4 and other chemokine receptors are implicated in vitreoretinal membrane formation.

Prolactin up-regulates cathepsin B and D expression in minor salivary glands of patients with Sjögren's syndrome.

Various proteases are expressed in the minor salivary glands (MSG) of patients with Sjögren's syndrome (SS), and as we have already shown, prolactin is neosynthesized in the acinar cells of patients with SS. The present study aims to characterize the influence of PRL on the expression of cathepsin B and D in the MSG of patients with SS. Cathepsin B and D expression was investigated immunohistochemically in MSG of 30 patients with SS and 15 healthy volunteers. The presence of cathepsin B and D mRNAs was checked in three SS patients and three control subjects by means of reverse transcription-polymerase chain reaction (RT-PCR). The specificity of the anti-cathepsin B and D antibodies used for the immunohistochemistry was checked by means of western blotting analysis. The influence of prolactin on the immunohistochemical expression of cathepsin B and D was quantitatively assayed by computer-assisted microscopy at three different doses (5, 50, and 500 ng/ml) on eight MSGs (four control subjects and four patients with SS) maintained ex vivo under organotypic cultures. This influence was also investigated at the mRNA level. Whereas cathepsin B immunopositivity was absent from glandular epithelial cells of healthy subjects and only slightly present in SS patients, cathepsin D immunoreactivity was considerably greater (p < 0.0001) in both the acini and the ducts of patients with SS as compared with control subjects. Cathepsin B, but not D, was also expressed in about 20% of infiltrating mononuclear cells of SS patients. Treatment of both healthy and SS minor salivary glands with PRL significantly (p < 0.05 top < 0.0001) enhanced cathepsin B and D expression in acinar and ductal cells at both protein and mRNA levels. PRL produced locally in MSGs of SS patients, but not those of healthy subjects, could play a role in the pathogenesis of Sjogren's syndrome, if only through the activation of proteolytic activity on the part of cathepsins B and D.

Big prolactin 60 kDa is overexpressed in salivary glandular epithelial cells from patients with Sjögren's syndrome.

Characterization of endogenous synthesis of prolactin (PRL) proteins and their cellular localization in labial salivary glands of patients with Sjogren's syndrome (SS) were achieved. PRL, PRL-receptors (PRL-R), and S100A6 protein were detected by immunohistochemistry. In situ prolactin synthesis was investigated in controls and SS patients by ex vivo incubation of minor salivary glands biopsies and immunoprecipitation assay. Increased PRL-immunoreactivity was found in cytoplasmic acinar epithelial cells in SS patients compared with normal subjects. PRL-R was distributed only in ductal epithelial cells in which S100A6 protein (a PRL-R-associated protein) was also present. PRL, PRL-R, or S100A6-immunoreactivity was not detected in infiltrating mononuclear cells. Immunoprecipitation demonstrated that PRL synthesis occurred in minor salivary glands with increased synthesis of two distinct PRL-like proteins (one major band at 60 kDa and a minor at 16 kDa) in SS glands compared with normal glands. Expression of PRL gene was demonstrated in SS salivary glands using RT-PCR. A positive correlation was found between the presence of PRL-like proteins in acinar epithelial cells of SS patients and clinical extraglandular manifestations. The presence of anti-Ro and anti-La antibodies also positively correlated with a higher percentage of PRL in acinar epithelial cells. In conclusion, PRL-like proteins are synthetized and overexpressed in glandular epithelial cells of labial salivary glands from SS patients and correlate with the aggressiveness of the disease.

Physical mapping of the CC-chemokine gene cluster on the human 17q11. 2 region.

Chemokines are a family of small secreted proteins that are involved in the trafficking of leukocytes by acting on G-protein-coupled receptors. Specific chemokines are also implicated in the regulation of angiogenesis and mobilization of hematopoietic cell precursors. Chemokines are subdivided into four groups on the basis of the relative positions of their conserved cysteines. For the CC-chemokine group, in which the first two (of four) conserved cysteines are adjacent, 22 members have been described so far. In this work, we have analyzed the genomic organization of these genes. We first assigned the genes encoding CC-chemokines to chromosomal regions and organized their relative positioning by using two radiation hybrid panels. Fifteen CC-chemokine genes were shown to be clustered within the 17q11.2 region of the human genome. These genes appeared to be segregated into two subclusters separated by about 2. 25 Mb (9 cR). Contigs of bacterial artificial chromosomes (BAC) covering these two subclusters were subsequently isolated and the localizations of the CC-chemokine genes within these contigs determined. The relative positioning of the BAC clones was determined with the help of fluorescence hybridization on combed genomic DNA. The cluster organization of the various CC-chemokine genes in the genome was found to be grossly consistent with their structural similarities. This map of the CC-chemokine gene cluster should facilitate the determination of the full sequence of the chromosomal region.

Mapping of the CCXCR1, CX3CR1, CCBP2 and CCR9 genes to the CCR cluster within the 3p21.3 region of the human genome.

Human CC-chemokine receptor genes are known to be clustered. The detailed structure of this cluster was established by radiation hybrid mapping, and organization of BAC contigs by fluorescence hybridization on combed genomic DNA. A main cluster of six genes (CCR1, CCR3, CCRL2, CCR5, CCR2 and CCXCR1), covered by four BACs, was mapped to the 3p21.3 region of the human genome. Five other genes (CCR9, CCBP2, CX3CR1, CCR8 and CCR4) were found to be spread over a relatively large region between this main cluster and the 3p telomere.

[Network for epidemiologic surveillance of animal diseases in Chad]. / Le réseau d'épidémiosurveillance des maladies animales au Tchad.

An epidemiosurveillance network for diseases of animals was introduced in Chad to ensure early reporting to animal husbandry organisations should the incidence of an existing disease increase, or should an exotic disease reappear. The network also serves for the collection of information on the principal diseases of livestock. A list of eight priority diseases was drawn up with specific surveillance objectives for each disease. Information (from surveys and sampling) from all new outbreaks of the diseases under surveillance is gathered by participants in the field (officials in public service and private veterinarians) and sent to the diagnostic laboratory, which examines the findings before disseminating them to the field. The first year of operation in the field has made it possible to evaluate the feasibility of the method and to collect fundamental epidemiological information on the diseases under surveillance. The advantage of the network is the provision of a means of communication between the field and the laboratory. The network enables collection of information in a standard form, the training of field agents and the organisation of the structure of the laboratory. Persistent problems are the motivation of some participants in the field and difficulties in communication which have to be overcome in order to obtain reliable data rapidly.