Factors associated with the orthopaedic surgeon's decision to recommend total joint replacement in hip and knee osteoarthritis: an international cross-sectional study of 1905 patients.

OBJECTIVE: To determine factors associated with orthopaedic surgeons' decision to recommend total joint replacement (TJR) in people with knee and hip osteoarthritis (OA). DESIGN: Cross-sectional study in eleven countries. For consecutive outpatients with definite hip or knee OA consulting an orthopaedic surgeon, the surgeon's indication of TJR was collected, as well as patients' characteristics including comorbidities and social situation, OA symptom duration, pain, stiffness and function (Western Ontario and McMaster Universities Osteoarthritis Index [WOMAC]), joint-specific quality of life, Osteoarthritis Research Society International (OARSI) joint space narrowing (JSN) radiographic grade (0-4), and surgeons' characteristics. Univariable and multivariable logistic regressions were performed to identify factors associated with the indication of TJR, adjusted by country. RESULTS: In total, 1905 patients were included: mean age was 66.5 (standard deviation [SD], 10.8) years, 1082 (58.0%) were women, mean OA symptom duration was 5.0 (SD 7.0) years. TJR was recommended in 561/1127 (49.8%) knee OA and 542/778 (69.7%) hip OA patients. In multivariable analysis on 516 patients with complete data, the variables associated with TJR indication were radiographic grade (Odds Ratio, OR for one grade increase, for knee and hip OA, respectively: 2.90, 95% confidence interval [1.69-4.97] and 3.30 [2.17-5.03]) and WOMAC total score (OR for 10 points increase: 1.65 [1.32-2.06] and 1.38 [1.15-1.66], respectively). After excluding radiographic grade from the analyses, on 1265 patients, greater WOMAC total score was the main predictor for knee and hip OA; older age was also significant for knee OA. CONCLUSION: Radiographic severity and patient-reported pain and function play a major role in surgeons' recommendation for TJR.

Reaching the theoretical resonance quality factor limit in coaxial plasmonic nanoresonators fabricated by helium ion lithography.

Optical antenna structures have revolutionized the field of nano-optics by confining light to deep subwavelength dimensions for spectroscopy and sensing. In this work, we fabricated coaxial optical antennae with sub-10-nanometer critical dimensions using helium ion lithography (HIL). Wavelength dependent transmission measurements were used to determine the wavelength-dependent optical response. The quality factor of 11 achieved with our HIL fabricated structures matched the theoretically predicted quality factor for the idealized flawless gold resonators calculated by finite-difference time-domain (FDTD). For comparison, coaxial antennae with 30 nm critical dimensions were fabricated using both HIL and the more common Ga focus ion beam lithography (Ga-FIB). The quality factor of the Ga-FIB resonators was 60% of the ideal HIL results for the same design geometry due to limitations in the Ga-FIB fabrication process.

A survey of expressed genes in Caenorhabditis elegans.

As an adjunct to the genomic sequencing of Caenorhabditis elegans, we have investigated a representative cDNA library of 1,517 clones. A single sequence read has been obtained from the 5' end of each clone, allowing its characterization with respect to the public databases, and the clones are being localized on the genome map. The result is the identification of about 1,200 of the estimated 15,000 genes of C. elegans. More than 30% of the inferred protein sequences have significant similarity to existing sequences in the databases, providing a route towards in vivo analysis of known genes in the nematode. These clones also provide material for assessing the accuracy of predicted exons and splicing patterns and will lead to a more accurate estimate of the total number of genes in the organism than has hitherto been available.

Helium ion microscopy for high-resolution visualization of the articular cartilage collagen network.

The articular cartilage collagen network is an important research focus because network disruption results in cartilage degeneration and patient disability. The recently introduced helium ion microscope (HIM), with its smaller probe size, longer depth of field and charge neutralization, has the potential to overcome the inherent limitations of electron microscopy for visualization of collagen network features, particularly at the nanoscale. In this study, we evaluated the capabilities of the helium ion microscope for high-resolution visualization of the articular cartilage collagen network. Images of rabbit knee cartilage were acquired with a helium ion microscope; comparison images were acquired with a field emission scanning electron microscope (FE-SEM) and a transmission electron microscope (TEM). Sharpness of example high-resolution helium ion microscope and field emission scanning electron microscope images was quantified using the 25-75% rise distance metric. The helium ion microscope was able to acquire high-resolution images with unprecedented clarity, with greater sharpness and three-dimensional-like detail of nanoscale fibril morphologies and fibril connections, in samples without conductive coatings. These nanoscale features could not be resolved by field emission scanning electron microscopy, and three-dimensional network structure could not be visualized with transmission electron microscopy. The nanoscale three-dimensional-like visualization capabilities of the helium ion microscope will enable new avenues of investigation in cartilage collagen network research.

Acute life-threatening extrinsic allergic alveolitis in a paint controller.

BACKGROUND: Occupational diisocyanate-induced extrinsic allergic alveolitis (EAA) is a rare and probably underestimated diagnosis. Two acute occupational EAA cases have been described in this context, but neither of them concerned hexamethylene diisocyanate (HDI) exposure. AIMS: To investigate the cause of a life-threatening EAA arising at work in a healthy 30-year-old female paint quality controller. METHODS: Occupational medical assessment, workplace evaluation, airborne and biological monitoring and immunodermatological tests. RESULTS: Diagnosis of EAA relied on congruent clinical and radiological information, confirmed occupational HDI exposure and positive IgG antibodies and patch tests. The patient worked in a small laboratory for 7 years, only occasionally using HDI-containing hardeners. While working with HDI for 6 h, she developed breathlessness, rapidly progressing to severe respiratory failure. Workplace HDI airborne exposure values ranged from undetectable levels to 4.25 p.p.b. Biological monitoring of urinary hexamethylene diamine in co-workers ranged from <1.0 to 15.4 µg/g creatinine. Patch tests 8 months later showed delayed skin reaction to HDI at 48 h. Subsequent skin biopsy showed spongiotic dermatitis with infiltration of CD4(+) and CD8(+) T cells. CONCLUSIONS: We believe this is the first reported case of acute life-threatening EAA following exposure to HDI. Low concentrations of airborne HDI and relatively high urinary hexamethylene diamine suggest significant skin absorption of HDI could have significantly contributed to the development of this acute occupational EAA.

A genetic map and recombination parameters of the human malaria parasite Plasmodium falciparum.

Genetic investigations of malaria require a genome-wide, high-resolution linkage map of Plasmodium falciparum. A genetic cross was used to construct such a map from 901 markers that fall into 14 inferred linkage groups corresponding to the 14 nuclear chromosomes. Meiotic crossover activity in the genome proved high (17 kilobases per centimorgan) and notably uniform over chromosome length. Gene conversion events and spontaneous microsatellite length changes were evident in the inheritance data. The markers, map, and recombination parameters are facilitating genome sequence assembly, localization of determinants for such traits as virulence and drug resistance, and genetic studies of parasite field populations.

Cardiac adaptation in asphyxiated infants treated with therapeutic hypothermia.

BACKGROUND: Hypoxic ischemic encephalopathy (HIE) affects  one to two newborns per 1,000 live births and oftentimes involves multi-organ insult. The objectives were to assess the evolution of cardiac function in infants with HIE treated with therapeutic hypothermia using echocardiography (ECHO). METHODS: Archived data during the period 2010-2016 was assessed. Amongst the infants with baseline ECHO assessments, a sub-cohort which had assessments in all the three phases (baseline/pre-active cooling [T1], cooling [T2] and rewarming [T3]) was analyzed separately. RESULTS: Thirty three infants formed part of the overall cohort, the gestation and birthweight were 39.6 ± 1.6 weeks and 3306 ± 583 g, respectively. Baseline (T1) information noted impaired cardiac performance (right ventricle stroke volume 1.08 ± 0.04 ml/kg, fractional area change [FAC] 24 ± 0.5% and tricuspid annular peak systolic excursion [TAPSE] 7.46 ± 0.11mm). Serial information was available for 24 of 33 infants. Cardiac function improved significantly between the cooling and the re-warming kphases. This included changes in right ventricular output (127 ± 34 vs 164 ± 47 ml/kg/min, p <0.01) and FAC (20 ± 3 vs 28 ± 2%, p<0.01). Pairwise comparisons for fractional shortening did not show significant changes. From the cooling to the rewarming phase, maximum change was noted in FAC (26.3 ± 9.8%) while minimum change was noted in fractional shortening (median, interquartile range) of 4.6% (1.4, 9.1). Significant correlation between TAPSE and time to peak velocity as a proportion of right ventricular ejection time was noted (r2 = 0.68, p <0.001). CONCLUSIONS: In infants with moderate to severe HIE, cardiac function evolves during various phases of therapeutic hypothermia. Low output state during cooling may be due to a combination of the disease state (HIE) and cooling therapy.

Building bioinformatics capacity in West Africa.

African scientists need more bioinformatics training in order to make innovative contributions to global biotechnology. To address the bioinformatics skills gap in West Africa, various training initiatives have been established in the sub-region. We present the activities of the West African Biotechnology Workshops (http://www.wabw.org/) in the past three years, and report on a symposium on bioinformatics and applied genomics in West Africa. To establish and sustain regional and national networks, stronger and increased government commitment by way of financial and infrastructural support for bioinformatics capacity building in West Africa is required.

Construction of modular and versatile plasmid vectors for the high-level expression of single or multiple genes in insects and insect cell lines.

We have constructed a series of plasmid vectors for the expression of foreign genes in insects or insect cell lines. We incorporated the Drosophila hsp70 and actin 5C promoters, as well as the hr5 enhancer-driven baculovirus ie1 promoter, into plasmids that allow convenient cloning of heterologous genes into multiple cloning sites. We combined these promoters with either a short, double poly-adenylation site derived from the Heliothis virescens p63 chaperonin gene, or with a fusion of the small t intron with the early 3' untranslated region and poly-adenylation sites of SV40. Unique eight base cutter restriction sites flanking the promoters and poly-adenylation sequences make it possible to transfer the entire transcription units into other sequence contexts, for example, into transposable elements or into other plasmids bearing selectable marker genes. It is also convenient to combine two of our transcription units on the same plasmid in order to express multiple genes simultaneously. To test the ability of our vectors to drive expression of reporter genes, luciferase derivatives were made of the expression plasmids and introduced into Aedes albopictus C6/36 cells by electroporation or into Anopheles gambiae embryos by biolistic particle bombardment. All three promoters directed high levels of luciferase expression. However, there were differences in their relative activities in the two experimental systems. In C6/36 cells, the actin 5C and hr5-ie1 promoters were significantly more active than the hsp70 promoter. In Anopheles embryos, hsp70 and actin 5C had maximal activities, while hr5-ie1 was weaker. We also found that the constructs containing the SV40 small t intron and early 3' untranslated region sequences had higher expression levels than their counterparts containing the Heliothis poly-adenylation sequence. Our most active construct combines the actin 5C promoter with the SV40 intron and 3' untranslated region sequences. This vector was also used to drive expression of a visible marker, the enhanced green fluorescent protein gene, resulting in readily visible green fluorescent protein expression in C6/36 cells.

Identification and characterization of an essential family of inositol polyphosphate 5-phosphatases (INP51, INP52 and INP53 gene products) in the yeast Saccharomyces cerevisiae.

We recently demonstrated that the S. cerevisiae INP51 locus (YIL002c) encodes an inositol polyphosphate 5-phosphatase. Here we describe two related yeast loci, INP52 (YNL106c) and INP53 (YOR109w). Like Inp51p, the primary structures of Inp52p and Inp53p resemble the mammalian synaptic vesicle-associated protein, synaptojanin, and contain a carboxy-terminal catalytic domain and an amino-terminal SAC1-like segment. Inp51p (108 kD), Inp52p (136 kD) and Inp53p (124 kD) are membrane-associated. Single null mutants (inp51, inp52, or inp53) are viable. Both inp51 inp52 and inp52 inp53 double mutants display compromised cell growth, whereas an inp51 inp53 double mutant does not. An inp51 inp52 inp53 triple mutant is inviable on standard medium, but can grow weakly on media supplemented with an osmotic stabilizer (1 M sorbitol). An inp51 mutation, and to a lesser degree an inp52 mutation, confers cold-resistant growth in a strain background that cannot grow at temperatures below 15 degrees. Analysis of inositol metabolites in vivo showed measurable accumulation of phosphatidylinositol 4,5-bisphosphate in the inp51 mutant. Electron microscopy revealed plasma membrane invaginations and cell wall thickening in double mutants and the triple mutant grown in sorbitol-containing medium. A fluorescent dye that detects endocytic and vacuolar membranes suggests that the vacuole is highly fragmented in inp51 inp52 double mutants. Our observations indicate that Inp51p, Inp52p, and Inp53p have distinct functions and that substrates and/or products of inositol polyphosphate 5-phosphatases may have roles in vesicle trafficking, membrane structure, and/or cell wall formation.

A genetic mapping system in Caenorhabditis elegans based on polymorphic sequence-tagged sites.

We devised an efficient genetic mapping system in the nematode Caenorhabditis elegans which is based upon the differences in number and location of the transposable element Tc1 between the Bristol and Bergerac strains. Using the nearly completed physical map of the C. elegans genome, we selected 40 widely distributed sites which contain a Tc1 element in the Bergerac strain, but not in the Bristol strain. For each site a polymerase chain reaction assay was designed that can distinguish between the Bergerac Tc1-containing site and the Bristol "empty" site. By combining appropriate assays in a single reaction, one can score multiple sites within single worms. This permits a mutation to be rapidly mapped, first to a linkage group and then to a chromosomal subregion, through analysis of only a small number of progeny from a single interstrain cross.

Transforming growth factor beta 1 dysregulation in a human oral carcinoma tumour progression model.

A human oral tumour progression model was established that consists of normal epithelial cells and three cell lines representing stages from dysplastic to metastatic cells. To investigate the impact of exogenous transforming growth factor-beta 1 on this model system, we analysed the responsiveness of those cells to transforming growth factor-beta 1 and explored the potential mechanism underlying the transforming growth factor-beta 1 activity. We found that the growth of all cell types, regardless of their stage of tumour progression, is inhibited by transforming growth factor-beta 1, although to different degrees. Transforming growth factor-beta 1 induced the expression of cyclin-dependent kinase inhibitors p15(INK4B), p21WAF1/(CIP1) and p27(KIP1). In contrast, transforming growth factor-beta 1 was found to stimulate the invasive potential of one cell type that represents the most advanced stage of tumour phenotype, suggesting that the impact of transforming growth factor-beta 1 on functional features of tumour cells other than cellular proliferation may play a significant role in the process of oral tumour progression.

[Study of the degradation reaction of paranitrosodimethylaniline by a C-nitrosoreductase of yeast]. / Etude de la réaction de dégradation de la paranitrosodiméthylanile par une C-nitrosoréductase de levure

We have purified, by a three step procedure, a yeast C-nitrosoreductase and studied its action on p-nitroso-N,N-dimethylaniline. Microcalorimetric measurements performed on the microcalorimeter LKB "batch", have been given the number of protons exchanged during the reaction : four protons are involved. Two are given by NADH and the others are supplied by the buffer. We could observe two steps in the catalytic mechanism. The enthalpy change of the first one is greater than that of the second. Spectrophotometric and polarographic experiments corroborate this results : two enzymatic steps could be demonstrated. The reduction of p-nitroso-N,N-dimethylaniline is characterized by a peak with a half wave potential at -0,31 V (in M Tris-HCl, pH 8,30). While the amplitude of this one decreases, a second wave appears at -1,03 V.

Acute effects of nifedipine on systolic and diastolic ventricular function in patients with chronic obstructive pulmonary disease.

To evaluate how nifedipine influences systolic and diastolic ventricular function, the effects of 20 mg sublingual nifedipine were studied in 13 stable COPD patients. Nifedipine induced no change in mean pulmonary arterial pressure, decreased mean arterial pressure, pulmonary and systemic vascular resistance index, and increased heart rate and cardiac index. It also caused an increase in right and left ventricular ejection fractions. The end-diastolic volume index of both ventricles remained unchanged, whereas the end-systolic volume index tended to decrease without reaching a significant level, and the right ventricular contractility increased. After nifedipine administration, right and left ventricular compliance increased. This study suggests that short-term administration of nifedipine improves the systolic function by a decrease in ventricular afterload and an increase in ventricular contractility and increases the ventricular compliance by a reflex sympathetic stimulation and an afterload reduction.

Dose dependency of aminophylline effects on hemodynamic and ventricular function in patients with chronic obstructive pulmonary disease.

The effects of aminophylline on pulmonary vascular tone, systemic hemodynamics, and ventricular ejection fractions reported in the literature show some discrepancies. We therefore studied in COPD patients the effects of aminophylline on hemodynamics, on ventricular ejection fractions, and on systolic and diastolic functions of each ventricle, and we measured simultaneously the blood level of the drug. The analysis of the data revealed a relationship between the blood level of aminophylline and the variations of right ventricular ejection fraction (RVEF) (r = 0.83, p = 0.005), left ventricular ejection fraction (LVEF) (r = 0.76, p = 0.017), pulmonary vascular resistance index (PVRI) (r = -0.58, p = 0.096), systemic vascular resistance index (SVRI) (r = -0.60, p = 0.08), and right ventricular peak systolic pressure/end-systolic volume index (RVPSP/ESVI) (r = -0.75, p = 0.02). Modifications of ejection fractions and vascular resistance indices were correlated for both ventricles (RVEF vs PVRI, r = -0.77, p = 0.01; LVEF vs SVRI, r = -0.76, p = 0.02). Finally, RVEF modifications was also correlated to RVPSP/ESVI variation (r = 0.78, p = 0.01). These results suggest that even within the therapeutic range (10 to 20 mg/L), the effects of aminophylline seemed to depend on its blood level. This dose dependency could explain the contradictory data reported in the literature concerning the effects of aminophylline on pulmonary and systemic hemodynamics and on ventricular function.

Prediction of pulmonary arterial pressure in chronic obstructive pulmonary disease by radionuclide ventriculography.

Pulmonary arterial hypertension represents an important parameter for the assessment of the severity of chronic bronchitis. The measurement of the pulmonary arterial pressure, however, requires invasive techniques of limited routine use because of costs and associated risks. The aim of this study is to evaluate whether the 81mKr right ventricular ejection fraction and parameters derived from equilibrium 99mTc red blood cells' right ventricular curve allow a better estimation of PAP than the 99mTc RVEF. In 41 patients with severe chronic bronchitis, the linear correlation between PAP and 99mTc RVEF was -0.61 (p less than 0.001). None of the parameters derived from the right ventricular curve was better correlated to PAP than the 99mTc RVEF. In 16 other chronic bronchitis patients, the 81mKr RVEF correlated moderately to PAP. In conclusion, the alternative isotopic methods proposed in this work do not provide a reliable estimation of pulmonary arterial pressure in patients with chronic bronchitis.

Does steroid pretreatment increase endotoxin release during clinical cardiopulmonary bypass?

OBJECTIVE: The mechanism involved in the endotoxemia frequently recognized during cardiopulmonary bypass remains unclear. It has also been suggested that endotoxin levels were higher in steroid-pretreated patients undergoing cardiopulmonary bypass. METHODS: Twenty patients undergoing cardiopulmonary bypass were randomly pretreated with steroids (methylprednisolone, 30 mg/kg) or placebo. Blood samples for endotoxin measurement were drawn simultaneously from the superior and inferior venae cavae before heparin administration, 5 and 50 minutes after the onset of bypass, 5 minutes after aortic declamping, at the end of bypass, and 1, 2, and 20 hours after the end of cardiopulmonary bypass. RESULTS: The perioperative variables in the two groups were similar. Blood endotoxin levels were higher in the inferior vena cava than in the superior vena cava immediately after the onset of bypass. Endotoxin levels in inferior vena cava blood were significantly lower in steroid-pretreated patients than those in patients not receiving steroids. CONCLUSIONS: Endotoxin is released during cardiopulmonary bypass from the region drained by the inferior vena cava. Steroid pretreatment may actually reduce endotoxin release during bypass.

An animal model for the assessment of gingival lesions.

A model of gingival inflammation was performed in Sprague-Dawley rats weighing 180-200 g. Mechanical bamboo stick-induced injury was inflammatory when bacteria contaminated the sticks. Bacteria were first obtained from gingival fluid collected from a patient with adult periodontitis. Another strain from Institut Pasteur (IP 6444) induced similar inflammation. Inflammation was then quantified 10 days later by means of elastase assays performed in gingival extracts. In parallel, elastic structures were observed and elastic fibers were quantified by automated image analysis. This technique of "impaction" was able to induce a gingival inflammatory reaction characterized by a significant increase of gingival elastase content, infiltration of gingival tissues by elicited cells, and gingival elastic fiber breakdown. These parameters were correlated, and measurement of one of them might be useful for pharmacological studies applied to the treatment of periodontal lesions. An example of results obtained from animals treated by heparine was shown.