Densitometer type and impact on risk assessment for osteoporosis.

Studies have shown a high correlation between measurements of bone mineral density (BMD) obtained on differentdual-energy X-ray absorptiometry machines. Challenger osteodensitometers (Diagnostic Medical System [DMS],Montpellier, France) are becoming widely used but little is known about their clinical performance. The aim of this study was to compare BMD measurements and the resulting patient classification based on T-scores obtained on a DMS Challenger device to those obtained on Hologic 4500A (Bedford, MA) device. Fifty-three volunteers were studied.The BMD of the spine and of the hip were simultaneously measured on both densitometers. BMD values obtained on the Challenger were significantly higher than those obtained with the Hologic QDR4500 (p<0.001). The correlations coefficients between the Hologic QDR4500 and the DMS Challenger measured BMDs were r=0.70 at the femoral neck, r=0.70 at the trochanter, and r=0.83 at the spine (p<0.001). Among the 35 postmenopausal women, there was discordance in the WHO T-score-based classification in 28 subjects (80%) at the spine, 18 subjects (52%) at the femoral neck, and 14 subjects (42%) at the trochanter. The intermachine agreement was low: The kappa score was -0.10 at the spine, 0.2 at the femoral neck, and 0.3 at the trochanter. In conclusion, this study cautions against the use of non established densitometers that leads to underdiagnosis of patients and, subsequently, to inappropriate treatment strategies.     

Aberrant expression of tight junction-related proteins ZO-1, claudin-1 and occludin in synovial sarcoma: an immunohistochemical study with ultrastructural correlation.

Synovial sarcoma demonstrates epithelial differentiation, either by light microscopy (biphasic synovial sarcoma) or by immunohistochemical/ultrastructural methods only (monophasic) and poorly differentiated synovial sarcoma. Although the glands of synovial sarcoma are known to have tight junction-like structures, far less is known about junction formation in the spindled component of synovial sarcomas. Additionally, it is unknown whether the tight junctions of synovial sarcoma are normally constituted. The tight junction is a multiprotein complex consisting of numerous proteins that include ZO-1, claudin-1 and occludin. A total of 35 cases of synovial sarcoma (13 biphasic, 14 monophasic and eight poorly differentiated) were immunostained for ZO-1, claudin-1 and occludin using commercially available antibodies, heat-induced epitope retrieval and standard avidin-biotin technique. When available, corresponding electron micrographs were reviewed. For five cases, the presence of either an SYT-SSX1 (three cases) or SYT-SSX2 (two cases) gene fusion was known. Positive cases showed particulate membrane staining. The glands of biphasic synovial sarcomas expressed ZO-1 (13/13), claudin-1 (12/13) and occludin (11/13) in a manner identical to normal glandular epithelia, at the apical portion of the lateral membrane. The spindle cells of biphasic synovial sarcomas showed abnormal circumferential membranous expression of ZO-1 (12/13), claudin-1 (6/13) and occludin (3/13). Monophasic synovial sarcomas expressed ZO-1 in a circumferential pattern (13/14) but less often claudin-1 (4/14) or occludin (3/14). Poorly differentiated synovial sarcomas expressed ZO-1 (8/8) and claudin-1 (6/8) but only rarely occludin (2/8). By electron microscopy, recognizable tight junctions were seen only in glands. No correlation was seen between histologic subtype or fusion type and expression of tight junction proteins. We conclude that the glands of biphasic synovial sarcomas show well-organized, true epithelial tight junctions. In contrast, the spindled cells of all synovial sarcomas show significant abnormalities in the expression and localization of tight junction proteins, suggesting partial and/or aberrant epithelial differentiation.     

The development of lymphocytes with T- or B-membrane determinants in the human foetus

The development of T- or B-membrane determinants on human foetal lymphoid cells was studied by the direct immunofluorescence technique, using a tetramethyl rhodamine isothiocyanate (TRITC) labelled horse antihuman T-cell conjugate (ATC) for the detection of T lymphocytes and a fluorescein isothiocyanate (FITC) labelled goat antihuman Fab conjugate for the demonstration of Ig-bearing B lymphocytes. Human foetal lymphocytes were also tested for spontaneous rosette formation with sheep red blood cells (SRBC).

Cell suspensions of liver, spleen, thymus, bone marrow and blood of twenty-five human foetuses of 5·5–26 weeks of gestational age have been investigated. ATC-positive lymphoid cells were first seen in the liver at 5·5 weeks; E rosette-forming cells (ERFC) and Ig-bearing lymphoid cells were first found at 9 weeks. ERFC were also present in the thymus at 9 weeks. By 12 weeks, fluorescent B and T lymphocytes were found in bone marrow and spleen. ERFC were also found in bone marrow at this age, but not in spleen. At 15 weeks, more than 80% of blood lymphoid cells had T or B determinants.

A difference in the reactivity of lymphoid cells with the ATC and their capacity to form E rosettes was observed. In liver and spleen, the ATC determinant was detectable before the SRBC receptor. In bone marrow, blood and thymus the ATC determinant was found on a higher percentage of lymphoid cells than was the SRBC receptor when those organs were first investigated. During the entire investigated period of gestation, the majority of lymphoid cells in liver and bone marrow did not react with either of the conjugates, nor did they form E rosettes. In all organs investigated, except in the thymus, lymphoid cells were occasionally seen which reacted with both conjugates. By the 16th week of foetal age, more than 90% of lymphoid cells in thymus, spleen and blood had acquired T- or B-membrane determinants.

     

Effects of montelukast and beclomethasone on airway function and asthma control

BACKGROUND: Maintaining asthma control is a major objective of therapy. Traditionally, the effectiveness of asthma therapy has been judged primarily by its effect on airway function rather than on multiaspect asthma control. OBJECTIVE: An inhaled corticosteroid and a leukotriene receptor antagonist were compared to determine whether they provided equivalent effects, as judged by days of asthma control. METHODS: In a randomized, multicenter, double-blind, placebo-controlled, parallel-group study, asthmatic patients (n = 782) with FEV(1) percent predicted values of between 50% and 85% and a weekly average beta-agonist use of more than 2 puffs per day were randomized to receive montelukast (10 mg daily), beclomethasone (200 microg twice daily), or placebo treatment for 6 weeks in a double-dummy fashion. We examined the distribution of the primary end point: percentage of days of asthma control. Secondary end points included FEV(1), albuterol use, occurrence of an asthma attack, asthma flare-up, rescue corticosteroid use, sustained asthma control, and adverse experiences. RESULTS: The percentage of days of asthma control was almost identical between the montelukast and beclomethasone groups (98% overlap in the distribution). Montelukast was at least equal to beclomethasone, and both were greater than placebo on the basis of frequency of asthma attacks, asthma flare-ups, and rescue corticosteroid use. Beclomethasone had a greater effect than montelukast and both treatments were better than placebo at improving FEV(1). CONCLUSIONS: Montelukast was as effective as beclomethasone, as judged by indices of clinical control other than FEV(1). When evaluating the outcome of montelukast therapy, FEV(1) might underestimate clinical effectiveness.     

Complete nucleotide sequence of mouse mammary tumor virus from jyg chinese wild mice: Absence of bacterial insertion sequences in the cloned viral gag gene

Mammary tumors of a newly isolated strain of Chinese wild mouse (JYG mouse) harbor exogenous mouse mammary tumor virus (MMTV). The complete nucleotide sequence of exogenous JYG-MMTV was determined on the proviral 5' long terminal repeat (LTR)(partial)-gag-pol-env-3' LTR (partial) fragment cloned into a plasmid vector and the cDNA sequence from JYG-MMTV producing cells. Similarly to the other MMTV species the LTR of JYG-MMTV contains an open reading frame (ORF). The amino acid sequence of the JYG-MMTV ORF resembles that of SW-MMTV (92% identity) and endogenous Mtv-7 (93% identity) especially at the C-terminal region. Thus, a functional similarity in T-cell receptor V beta recognition as a superantigen is implicated among these MMTV species. Analysis of the viral gag nucleotide sequence revealed that this gene is not disrupted by the bacterial insertion sequence IS1 or IS2, which have been reported to be present in the majority of the plasmids containing the gag region. Comparison of amino acid sequences of JYG-MMTV with those of BR6-MMTV showed that over 96% of the amino acids of gag, pol, protease and env products are identical. These results suggest the intact nature of the nucleotide sequence of the near full-length MMTV genome cloned in the plasmid.     

Enzymatic hydrolysis of low temperature alkali pretreated wheat straw using immobilized β-xylanase nanoparticles

A low temperature alkali (LTA) pretreatment method was used to treat wheat straw. In order to obtain good results, different factors like temperature, incubation time, NaOH concentration and solid to liquid ratio for the pretreatment process were optimized. Wheat straw is a potential biomass for the production of monomeric sugars. The objective of the current study was to observe the saccharification (%) of wheat straw with immobilized magnetic nanoparticles (MNPs). For this purpose, immobilized MNPs of purified β-xylanase enzyme was used for hydrolysis of pretreated wheat straw. Wheat straw was pretreated using the LTA method and analyzed by SEM analysis. After completion of the saccharification process, saccharification% was calculated by using a DNS method. Scanning electron micrographs revealed that the hemicellulose, cellulose and lignin were partially removed and changes in the cell wall structure of the wheat straw had caused it to become deformed, increasing the specific surface area, so more fibers of the wheat straw were exposed to the immobilized β-xylanase enzyme after alkali pretreatment. The maximum saccharification potential of wheat straw was about 20.61% obtained after pretreatment with optimized conditions of 6% NaOH, 1/10 S/L, 30 °C and 72 hours. Our results indicate the reusability of the β-xylanase enzyme immobilized magnetic nanoparticles and showed a 15% residual activity after the 11th cycle. HPLC analysis of the enzyme-hydrolyzed filtrate also revealed the presence of sugars like xylose, arabinose, xylobiose, xylotriose and xylotetrose. The time duration of the pretreatment has an important effect on thermal energy consumption for the low-temperature alkali method.

A low temperature alkali (LTA) pretreatment method was used to treat wheat straw.     

EPIDEMIOLOGIE DE L’HYPERTENSION ARTERIELLE EN TUNISIE.Etude Hammam Sousse/Sahloul Heart Study (HSHS)

Introduction: Tunisia is experiencing a double burden of morbidity, characterized by the explosion of cardiovascular diseases and their risk factors including arterial Hypertension. The objective of this study, based on the HSHS cohort (Hammam Sousse Sahloul Heart Study), was to determine the prevalence of hypertension in the general population and to identify its predisposing factors. Methods: HSHS is a cardiovascular health promotion initiative in the city of Hammam Sousse (Tunisia). The study was conducted via a random sample of households, using the WHO PEV technique, made up of 33 clusters, of 33 households each. All people aged 20 and over, included, benefited from a questionnaire, a physical examination and a biological assessment. The Systolic Blood Pressure (SBP) and the Diastolic Blood Pressure (DBP) were measured from the average of the last two measurements, by an OMRON type tensiometer, of suitable width. These prevalences were adjusted according to sex and age group, by their weighting coefficients in the general population, and they were accompanied by their 95% CIs. Binary logistic regression was conducted to identify independent factors associated with hypertension. Results: The study population was composed of 481 men (33.4%) and 960 women (66.6%), with an average age of 49.6±16.35 years in males (M) and 46.6±16.18 in females (F). In addition to the family history of hypertension, the sufficient weekly consumption of vegetables and fruits was low (M: 32.4%, F: 24.9%). The adjusted rate of hypertension in the adult study population was 32.5%, 95%CI[31.9-33.1] (M: 36.4%, 95%CI[35, 5-37.3]; F: 28.4%; 95% CI[27.6-29.2]), reaching in the age group of 60 years and above: M: 74.6% (95%CI[66.9-82.3], F: 82.7% (95%CI[73.8-83.6]) Multivariate analysis identified five independent factors significantly associated with hypertension: male sex (ORa=1.55 [1.18-2.03]), age over 40 years (ORa=6.54[4.70-9.11]), low level of schooling (ORa=1.80 [1.36-2.38]), low physical activity (ORa=1.42[1.07-1.88]) and high socio-economic level (ORa=1 .84 [1.30-2.63]). Conclusion: The HSHS study confirmed the high prevalence of hypertension, and the extent of its low detection and control. Hence the need for a universal approach to health promotion, oriented towards the general population, piloted by its local organizations, based on the adoption of a healthy lifestyle, and centered on physical activity.     

Influence of Gypsum Waste Utilization on Properties and Leachability of Fired Clay Brick

Wastewater treatment activities in the chemical industry have generated abundant gypsum waste, classified as scheduled waste (SW205) under the Environmental Quality Regulations 2005. The waste needs to be disposed into a secure landfill due to the high heavy metals content which is becoming a threat to the environment. Hence, an alternative disposal method was evaluated by recycling the waste into fired clay brick. The brick samples were incorporated with different percentages of gypsum waste (0% as control, 10, 20, 30, 40 and 50%) and were fired at 1050 °C using 1 °C per minute heating rate. Shrinkage, dry density, initial rate of suction (IRS) and compressive strength tests were conducted to determine the physical and mechanical properties of the brick, while the synthetic precipitation leaching procedure (SPLP) was performed to scrutinize the leachability of heavy metals from the crushed brick samples. The results showed that the properties would decrease through the incorporation of gypsum waste and indicated the best result at 10% of waste utilization with 47.5% of shrinkage, 1.37% of dry density, 22.87% of IRS and 28.3% of compressive strength. In addition, the leachability test highlighted that the concentrations of Fe and Al was significantly reduced up to 100% from 4884 to 3.13 ppm (Fe) and from 16,134 to 0.81 ppm (Al), respectively. The heavy metals content in the bricks were oxidized during the firing process, which signified the successful remediation of heavy metals in the samples. Based on the permissible incorporation of gypsum waste into fired clay brick, this study promised a more green disposing method for gypsum waste, and insight as a potential towards achieving a sustainable end product.     

A key claudin extracellular loop domain is critical for epithelial barrier integrity

Intercellular tight junctions (TJs) regulate epithelial barrier properties. Claudins are major structural constituents of TJs and belong to a large family of tetra-spanning membrane proteins that have two predicted extracellular loops (ELs). Given that claudin-1 is widely expressed in epithelia, we further defined the role of its EL domains in determining TJ function. The effects of several claudin-1 EL mimetic peptides on epithelial barrier structure and function were examined. Incubation of model human intestinal epithelial cells with a 27-amino acid peptide corresponding to a portion of the first EL domain (Cldn-1(53-80)) reversibly interfered with epithelial barrier function by inducing the rearrangement of key TJ proteins: occludin, claudin-1, junctional adhesion molecule-A, and zonula occludens-1. Cldn-1(53-80) associated with both claudin-1 and occludin, suggesting both the direct interference with the ability of these proteins to assemble into functional TJs and their close interaction under physiological conditions. These effects were specific for Cldn-1(53-80), because peptides corresponding to other claudin-1 EL domains failed to influence TJ function. Furthermore, the oral administration of Cldn-1(53-80) to rats increased paracellular gastric permeability. Thus, the identification of a critical claudin-1 EL motif, Cldn-1(53-80), capable of regulating TJ structure and function, offers a useful adjunct to treatments that require drug delivery across an epithelial barrier.     

Detection of Vi-negative Salmonella enterica serovar typhi in the peripheral blood of patients with typhoid fever in the Faisalabad region of Pakistan

The synthesis and transportation proteins of the Vi capsular polysaccharide of Salmonella enterica serovar Typhi (serovar Typhi) are encoded by the viaB operon, which resides on a 134-kb pathogenicity island known as SPI-7. In recent years, Vi-negative strains of serovar Typhi have been reported in regions where typhoid fever is endemic. However, because Vi negativity can arise during in vitro passage, the clinical significance of Vi-negative serovar Typhi is not clear. To investigate the loss of Vi expression at the genetic level, 60 stored strains of serovar Typhi from the Faisalabad region of Pakistan were analyzed by PCR for the presence of SPI-7 and two genes essential for Vi production: tviA and tviB. Nine of the sixty strains analyzed (15%) tested negative for both tviA and tviB; only two of these strains lacked SPI-7. In order to investigate whether this phenomenon occurred in vivo, blood samples from patients with the clinical symptoms of typhoid fever were also investigated. Of 48 blood samples tested, 42 tested positive by fliC PCR for serovar Typhi; 4 of these were negative for tviA and tviB. Three of these samples tested positive for SPI-7. These results demonstrate that viaB-negative, SPI-7-positive serovar Typhi is naturally occurring and can be detected by PCR in the peripheral blood of typhoid patients in this region. The method described here can be used to monitor the incidence of Vi-negative serovar Typhi in regions where the Vi vaccine is used.