The effect of osteoarthritis definition on prevalence and incidence estimates: a systematic review

OBJECTIVE

To understand the differences in prevalence and incidence estimates of osteoarthritis (OA), according to case definition, in knee, hip and hand joints.

METHOD

A systematic review was carried out in PUBMED and SCOPUS databases comprising the date of publication period from January 1995 to February 2011. We attempted to summarise data on the incidence and prevalence of OA according to different methods of assessment: self-reported, radiographic and symptomatic OA (clinical plus radiographic). Prevalence estimates were combined through meta-analysis and between-study heterogeneity was quantified.

RESULTS

Seventy-two papers were reviewed (nine on incidence and 63 on prevalence). Higher OA prevalences are seen when radiographic OA definition was used for all age groups. Prevalence meta-analysis showed high heterogeneity between studies even in each specific joint and using the same OA definition. Although the knee is the most studied joint, the highest OA prevalence estimates were found in hand joints. OA of the knee tends to be more prevalent in women than in men independently of the OA definition used, but no gender differences were found in hip and hand OA. Insufficient data for incidence studies didn't allow us to make any comparison according to joint site or OA definition.

CONCLUSIONS

Radiographic case definition of OA presented the highest prevalences. Within each joint site, self-reported and symptomatic OA definitions appear to present similar estimates. The high heterogeneity found in the studies limited further conclusions.

Isolation and partial nucleotide sequence of a cDNA clone for human histocompatibility antigen HLA-B by use of an oligodeoxynucleotide primer

We have isolated a cDNA clone for one of the HLA-B locus alloantigens by hybridization with a 30-nucleotide-long DNA probe. The probe was isolated from a reverse transcriptase (RNA-dependent DNA nucleotidyltransferase)-catalyzed cDNA synthesis reaction on poly(A)-mRNA in which an oligonucleotide (5'-32P)dC-T-T-C-T-C-C-A-C-A-TOH served as a primer and in which dideoxynucleoside triphosphates were used to reduce the size and heterogeneity of the cDNA products. The desired cDNA clone was isolated from a library of recombinant cDNA clones in the plasmid pBR322. The partial nucleotide sequence of the cDNA clone corresponds to the amino acid sequence of HLA-B7 antigen. The approach described in this paper is extremely sensitive and may be useful in cloning other genes for which the corresponding mRNA is present at low levels. This cDNA clone is nearly full length and can be used to isolate and to study the genes within the HLA region and to obtain expression of HLA-B peptides in cells.

Three cDNA clones encoding mouse transplantation antigens: homology to immunoglobulin genes

We constructed cDNA libraries from poly(A)+ RNA isolated from cell lines of two different inbred strains of mice, and screened the libraries with a cDNA clone encoding a human transplantation antigen. Three cDNA clones were identified, sequenced and found to encode amino acid sequences highly homologous to portions of a known mouse transplantation antigen. Comparison of the cDNA sequences of mouse transplantation antigens with the constant region domains of the mouse immunoglobulin mu gene reveals a striking homology, which suggests that the two genes share a common ancestor. Antibody genes undergo DNA rearrangement during B cell differentiation that are correlated with their expression. In contrast, DNA blots with these cDNA probes suggest that the genes for the transplantation antigens are not rearranged in the genomes of liver or embryo cells, which express these antigens, as compared with sperm cells, which do not express these antigens. In Bam Hl-digested liver DNAs from different inbred strains of mice, 10-15 bands of hybridization were found. Accordingly, the genes encoding the transplantation antigens appear to constitute a multigene family with similar gene numbers in different mice.

Short-term effects of social exclusion at work and worries on sleep

The present study investigated short-term effects of daily social exclusion at work on various indicators of sleep quality and tested the mediating role of work-related worries using a time-based diary study with ambulatory assessments of sleep quality. Ninety full-time employees participated in a 2-week data collection. Multilevel analyses revealed that daily workplace social exclusion and work-related worries were positively related to sleep fragmentation in the following night. Daily social exclusion, however, was unrelated to sleep onset latency, sleep efficiency and self-reported sleep quality. Moreover, worries did not mediate the effect of social exclusion at work on sleep fragmentation. Theoretical and practical implications of the results are discussed.

Divergent Approaches to Virulence in C. albicans and C. glabrata: Two Sides of the Same Coin

Candida albicans and Candida glabrata are the two most prevalent etiologic agents of candidiasis worldwide. Although both are recognized as pathogenic, their choice of virulence traits is highly divergent. Indeed, it appears that these different approaches to fungal virulence may be equally successful in causing human candidiasis. In this review, the virulence mechanisms employed by C. albicans and C. glabrata are analyzed, with emphasis on the differences between the two systems. Pathogenesis features considered in this paper include dimorphic growth, secreted enzymes and signaling molecules, and stress resistance mechanisms. The consequences of these traits in tissue invasion, biofilm formation, immune system evasion, and macrophage escape, in a species dependent manner, are discussed. This review highlights the observation that C. albicans and C. glabrata follow different paths leading to a similar outcome. It also highlights the lack of knowledge on some of the specific mechanisms underlying C. glabrata pathogenesis, which deserve future scrutiny.

Illegitimate tasks and sleep quality: an ambulatory study

The current study investigated the short-term effect of illegitimate tasks on sleep quality, assessed by actigraphy. Seventy-six employees of different service jobs participated in a 2-week data collection. Data were analysed by way of multilevel analyses. As predicted, illegitimate tasks were positively related to sleep fragmentation and sleep-onset latency, but not to sleep efficiency and not to sleep duration. Time pressure, social stressors at work and at home, and the value of the dependent variable from the previous day were controlled. Results confirm the predictive power of illegitimate tasks for a variable that can be considered crucial in the development of long-term outcomes of daily experiences.

Prognostic value of E-cadherin immunoexpression in patients with primary ovarian carcinomas

PURPOSE

To analyse the negative versus positive immunoexpression of E-cadherin in patients with primary ovarian carcinomas, and determine its significance in relation to clinicopathological features, overall and recurrence-free survival (RFS).

PATIENTS AND METHODS

The protein expression of E-cadherin was immunohistochemically evaluated in formalin-fixed, paraffin-embedded samples in 104 patients with primary ovarian carcinomas. The clinicopathological factors studied were age, FIGO staging, histological type, tumour differentiation, the appearance of the ovarian capsule, peritoneal implants and residual tumour after cytoreductive surgery. Overall survival and RFS were evaluated using the Kaplan-Meier method, and multivariate analysis was completed using the Cox regression model.

RESULTS

Of the 104 carcinomas, negative E-cadherin immunoexpression was observed in seven (7%) cases, and positive immunoexpression in 97 (93%). E-cadherin categorised into negative versus positive expression did not associate with any of the established clinicopathological parameters. However, negative E-cadherin expression significantly predicted a poorer overall survival when compared with positive expression (P=0.006). In the multivariate analyses, negative E-cadherin and the presence of residual tumour after cytoreductive surgery were independent prognostic factors for survival (P=0.014 and P=0.034, respectively).

CONCLUSIONS

The presence of residual tumour after primary cytoreductive surgery and negative E-cadherin expression seem to be useful markers in patients with ovarian carcinomas likely to have an unfavourable clinical outcome. The assessment of E-cadherin immunoreactivity may be a useful prognostic indicator in ovarian cancer, complementary to established prognostic factors.

Social stressors at work, sleep quality and psychosomatic health complaints--a longitudinal ambulatory field study

There is increasing evidence that occupational stress increases psychosomatic health complaints in the long run. However, the underlying mechanisms are still unclear. The present longitudinal actigraphy field study investigated the role of sleep quality--objectively assessed sleep-onset latency, sleep efficiency and sleep fragmentation, and subjectively assessed sleep quality--as a mediator in the relationship between stressful work conditions at time 1 and psychosomatic health complaints at time 2. A longitudinal hierarchical regression analysis revealed that social stressors at work were positively related to objectively assessed sleep fragmentation and to psychosomatic health complaints. Moreover, objectively assessed sleep fragmentation mediated the effect of social stressors at work on psychosomatic health complaints. Contrary to our expectations, social stressors at work were not related to other sleep quality parameters (i.e. sleep-onset latency, sleep efficiency and subjectively assessed sleep quality) during follow-up. Sleep fragmentation is discussed as an important consequence of social stressors at work that increase the risk of psychosomatic health complaints in the long run.

HER2 polymorphism and breast cancer risk in Portugal

Breast cancer is a major public health problem around the world, and its carcinogenesis is not yet well understood. The human epidermal growth factor Receptor 2 (HER2) seems to play an important role in the development of this neoplasia, and genetic alterations in this gene, such as point mutations and polymorphisms have been detected in breast cancer patients. We analysed the frequency of a single nucleotide polymorphism in the HER2 gene in blood samples from 152 breast cancer patients and 146 healthy controls using the polymerase chain reaction methodology, followed by restriction fragment length polymorphism (PCR-RFLP). We found a twofold increase in risk of breast cancer in women who are carriers of a Val allele genotype-Ile/Val and Val/Val genotypes [odds ratio (OR)=2.00; 95% confidence interval (CI) 1.23-3.25; P=0.005]. Our results indicate an association between the presence of the Val allele in the HER2 polymorphism and the risk of breast cancer. Further studies are needed to evaluate the role of this polymorphism in the behaviour of breast cancer.

Autotransplant conditioning regimens for aggressive lymphoma: are we on the right road?

High-dose chemotherapy and autologous stem cell transplant (ASCT) is the standard approach for chemosensitive, relapsed aggressive non-Hodgkin's lymphoma (NHL). Various conditioning regimens have been used as treatment before ASCT and disease-free (DFS) and overall survival (OS) rates range from 34 to 60% and 26 to 46%, respectively. To date, few comparative randomized trials have been performed and no regimen has demonstrated superiority to another. Reduction of disease relapse remains the major hurdle for improving patient outcome and in vitro and in vivo purging of lymphoma cells has not necessarily enhanced results. Rituximab pre-mobilization and post-transplant appear to provide better response rates with OS approaching 87-91% at 2-3 years. Newer approaches with radioimmunotherapy may raise DFS to 78% and OS to 93%, albeit with short follow-up. Advances in the conditioning regimens and supportive care have reduced transplant-related mortality to less than 10%. In this review we discuss commonly utilized conditioning regimens, describe their pros and cons and address purging and present conditioning strategies. Owing to the poor outcome with conventional chemotherapy in mantle cell, Burkitt's and T-cell lymphoma, we propose the standard approach of front-line ASCT for these high-risk lymphoma patients. Finally, we will present novel strategies, which can enhance the anti-lymphoma effect, at the same time reducing toxicity, to improve the outcome of ASCT in NHL patients.

Multi-channel attention-fusion neural network for brain age estimation: Accuracy, generality, and interpretation with 16,705 healthy MRIs across lifespan

Brain age estimated by machine learning from T1-weighted magnetic resonance images (T1w MRIs) can reveal how brain disorders alter brain aging and can help in the early detection of such disorders. A fundamental step is to build an accurate age estimator from healthy brain MRIs. We focus on this step, and propose a framework to improve the accuracy, generality, and interpretation of age estimation in healthy brain MRIs. For accuracy, we used one of the largest sample sizes (N = 16,705). For each subject, our proposed algorithm first explicitly splits the T1w image, which has been commonly treated as a single-channel 3D image in other studies, into two 3D image channels representing contrast and morphometry information. We further proposed a "fusion-with-attention" deep learning convolutional neural network (FiA-Net) to learn how to best fuse the contrast and morphometry image channels. FiA-Net recognizes varying contributions across image channels at different brain anatomy and different feature layers. In contrast, multi-channel fusion does not exist for brain age estimation, and is mostly attention-free in other medical image analysis tasks (e.g., image synthesis, or segmentation), where treating channels equally may not be optimal. For generality, we used lifespan data 0-97 years of age for real-world utility; and we thoroughly tested FiA-Net for multi-site and multi-scanner generality by two phases of cross-validations in discovery and replication data, compared to most other studies with only one phase of cross-validation. For interpretation, we directly measured each artificial neuron's correlation with the chronological age, compared to other studies looking at the saliency of features where salient features may or may not predict age. Overall, FiA-Net achieved a mean absolute error (MAE) of 3.00 years and Pearson correlation r=0.9840 with known chronological ages in healthy brain MRIs 0-97 years of age, comparing favorably with state-of-the-art algorithms and studies for accuracy and generality across sites and datasets. We also provided interpretations on how different artificial neurons and real neuroanatomy contribute to the age estimation.

Mice with disrupted midsized and heavy neurofilament genes lack axonal neurofilaments but have unaltered numbers of axonal microtubules

Mammalian neurofilaments are assembled from the light (NF-L), midsized (NF-M), and heavy (NF-H) neurofilament proteins. While NF-M and NF-H cannot self-assemble into homopolymers, the data concerning NF-L has been more contradictory. In vitro bovine, porcine, and murine NF-L can homopolymerize in the absence of other subunits. However, in vivo studies suggest that neither rat nor mouse NF-L can form filaments when transfected alone into cells lacking endogenous intermediate filaments. By contrast, human NF-L forms homopolymers in similar cell lines. Recently we generated mice with null mutations in the NF-M and NF-H genes. To determine if mouse NF-L can homopolymerize in mouse axons, NF-M and NF-H null mutants were bred to create a line of double mutant animals. Here we show that axons in NF-M/H double mutant animals are largely devoid of 10-nm filaments. Instead, the axoplasm is transformed to a microtubule-based cytoskeleton-although the lack of any increase in tubulin levels per unit length of nerve or of increases in microtubule numbers relative to myelin sheath thickness argues that microtubules are not increased in response to the loss of neurofilaments. Thus in vivo rodent neurofilaments are obligate heteropolymers requiring NF-L plus either NF-M or NF-H to form a filamentous network.

Microevolution of the pathogenic yeasts Candida albicans and Candida glabrata during antifungal therapy and host infection

Infections by the pathogenic yeasts Candida albicans and Candida glabrata are among the most common fungal diseases. The success of these species as human pathogens is contingent on their ability to resist antifungal therapy and thrive within the human host. C. glabrata is especially resilient to azole antifungal treatment, while C. albicans is best known for its wide array of virulence features. The core mechanisms that underlie antifungal resistance and virulence in these pathogens has been continuously addressed, but the investigation on how such mechanisms evolve according to each environment is scarcer. This review aims to explore current knowledge on micro-evolution experiments to several treatment and host-associated conditions in C. albicans and C. glabrata. The analysis of adaptation strategies that evolve over time will allow to better understand the mechanisms by which Candida species are able to achieve stable phenotypes in real-life scenarios, which are the ones that should constitute the most interesting drug targets.

Potential of synthetic chalcone derivatives to prevent marine biofouling

Biofouling represents a major economic, environmental and health concern for which new eco-friendly solutions are needed. International legislation has restricted the use of biocidal-based antifouling coatings, and increasing efforts have been applied in the search for environmentally friendly antifouling agents. This research work deals with the assessment of the interest of a series of synthetic chalcone derivatives for antifouling applications. Sixteen chalcone derivatives were synthesized with moderate yields (38-85%). Antifouling bioactivity of these compounds was assessed at different levels of biological organization using both anti-macrofouling and anti-microfouling bioassays, namely an anti-settlement assay using mussel (Mytilus galloprovincialis) larvae, as well as marine bacteria and microalgal biofilms growth inhibition bioassays. Results showed that three compounds (11, 12, and 16) were particularly active against the settlement of mussel larvae (EC₅₀ 7.24-34.63 μM), being compounds 12 and 16 also able to inhibit the growth of microfouling species (EC₅₀ 4.09-20.31 μM). Moreover, the most potent compounds 12 and 16 were found to be non-toxic to the non-target species Artemia salina (<10% mortality at 25 μM). A quantitative structure-activity relationship model predicted that descriptors describing the ability of molecules to form hydrogen bonds and encoding the shape, branching ratio and constitutional diversity of the molecule were implied in the antifouling activity against the settlement of mussel larvae. This work elucidates for the first time the relevance of synthesizing chalcone derivatives to generate new non-toxic products to prevent marine biofouling.

Characterization of a new cell line (ESKOL) resembling hairy-cell leukemia: a model for oncogene regulation and late B-cell differentiation

A B-lymphoblastoid cell line ESKOL, composed of differentiated cells resembling hairy-cell leukemia (HCL) has been established from the peripheral blood (PB) of a HCL patient. Morphologically, ESKOL cells share several features with HCL B cells. Flow cytometric analysis revealed that ESKOL cells express HC2, CD21, PCA-1, CD24, FMC7, and CD25. Analysis by Northern-blot hybridization indicated that cultured cells expressed the oncogenes c-myc, H-ras and c-fos. RNA from 3T3 cells transfected with ESKOL DNA hybridized with H-ras and c-fos DNA probes. The ESKOL cells cultured in the presence of increasing concentrations, of alpha interferon demonstrated a decrease in the rate of cellular growth and an increase in the expression of CD21, CD25, FMC7 and PCA-1. Scanning electron microscopy revealed that cells incubated in the presence of alpha interferon underwent membranous changes with a loss of villosity. These observations suggest that IFN tends to drive HC out of their developmental arrest towards maturation.

Histopathology of interscapular brown adipose tissue, thyroid, and pancreas in 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-treated rats

The time course of histological changes was studied in rats lethally intoxicated (150 micrograms/kg) with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). In addition to TCDD-caused tissue damage described by others, the thyroid, pancreas, and interscapular brown adipose tissue (IBAT) were identified as tissues affected by TCDD. Because histological changes in the thyroid and pancreas occurred late (7 days after dosing), these effects are viewed as secondary due to altered hormonal homeostases. Both light and electron microscopic examination of IBAT identified this tissue as a target in TCDD toxicity. Histological changes in IBAT are characterized by three phases: (1) "fatty" IBAT (Days 1 to 3 after dosing); (2) fat depletion accompanied by glycogen accumulation (Days 4 to 7 after dosing); and (3) complete fat and glycogen depletion together with massive cellular damage (Days 8 to 14), particularly affecting the mitochondria. It is concluded that brown adipose tissue is a primary target in TCDD toxicity. It seems that destruction of brown adipose tissue by TCDD leads to an energy imbalance resulting in reduced oxygen consumption which forces animals to contribute a greater proportion of energy to the maintenance of their body temperature by anaerobic pathways. It is suggested that this less efficient energy utilization is the cause of a wasting syndrome.

Cyclophosphamide, etoposide and G-CSF to mobilize peripheral blood stem cells for autologous stem cell transplantation in patients with lymphoma

We aimed to assess the effectiveness of cyclophosphamide, etoposide and G-CSF (C+E) to mobilize peripheral blood stem cells for autologous stem cell transplantation in patients with lymphoma. A matched cohort study was performed comparing patients mobilized with C+E to patients mobilized with cyclophosphamide and G-CSF (C alone). Patients were matched for disease, prior radiotherapy and a chemotherapy score reflecting the amount and type of prior chemotherapy. Thirty-eight consecutive patients mobilized with C+E were compared with 38 matched controls. C+E was equivalent to C alone in terms of numbers of patients achieving a minimum threshold of > or =2 x 10(6)/kg CD34(+)cells (82% vs 79%, P = 0.74). C+E was superior, however, in terms of total CD34(+) yield (6.35 vs 3.3 x 10(6)/kg, P < 0.01), achieving a target graft of > or =5 x 10(6)/kg (55% vs 34%, P = 0.04) and obtaining both a minimum (61% vs 32%, P < 0.01) and target (45% vs 13%, P < 0.01) graft in one apheresis. This superiority was largely confined to patients with lower chemotherapy scores. There was no difference in neutrophil and platelet recovery or transfusion requirements for those who subsequently received high-dose therapy and stem cell transplantation. Thus, C+E improves the efficiency of peripheral blood stem cell collection, but does not increase the number of patients who can proceed to transplantation. Most of the benefit of the regimen was confined to patients who had not received extensive prior therapy. Novel strategies are required to increase the collection efficiency of 'hard to mobilize' patients.

Portuguese higher education students' adaptation to online teaching and learning in times of the COVID-19 pandemic: personal and contextual factors

The COVID-19 pandemic brought about a global crisis affecting all sectors of society. Higher education is no exception. The closure of higher education institutions has dictated a sudden and unexpected transition from face-to-face to remote teaching to mitigate the spread of the SARS-CoV-2. This paper draws upon a wider piece of research which aimed to understand how higher education students adapted to the closure of their institution and how they looked at their experience of online teaching and learning. In total, 2718 students from different Portuguese higher education institutions participated in the study. Findings showed that both personal and contextual factors explained students' positive or negative adaptation to online teaching and learning as a result of the closure of higher education institutions. Institutional and pedagogical responses, individual self-regulatory and socio-emotional competencies and adequate resources were factors that led to either a more positive or negative student experience of online teaching and learning in times of COVID-19.

Is mitral valve prolapse a congenital or acquired disease?

The prevalence of mitral valve prolapse (MVP) at birth was studied in 1,734 consecutive newborns without congenital structural heart disease. We have not identified any case of an unequivocal pattern of MVP using auscultatory and echocardiographic diagnostic criteria. Our data argue for the concept that MVP is an acquired disease.