123 research outputs found

    Reproducibility and day time bias correction of optoelectronic leg volumetry: a prospective cohort study

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    Background Leg edema is a common manifestation of various underlying pathologies. Reliable measurement tools are required to quantify edema and monitor therapeutic interventions. Aim of the present work was to investigate the reproducibility of optoelectronic leg volumetry over 3 weeks' time period and to eliminate daytime related within-individual variability. Methods Optoelectronic leg volumetry was performed in 63 hairdressers (mean age 45 ± 16 years, 85.7% female) in standing position twice within a minute for each leg and repeated after 3 weeks. Both lower leg (legBD) and whole limb (limbBF) volumetry were analysed. Reproducibility was expressed as analytical and within-individual coefficients of variance (CVA, CVW), and as intra-class correlation coefficients (ICC). Results A total of 492 leg volume measurements were analysed. Both legBD and limbBF volumetry were highly reproducible with CVA of 0.5% and 0.7%, respectively. Within-individual reproducibility of legBD and limbBF volumetry over a three weeks' period was high (CVW 1.3% for both; ICC 0.99 for both). At both visits, the second measurement revealed a significantly higher volume compared to the first measurement with a mean increase of 7.3 ml ± 14.1 (0.33% ± 0.58%) for legBD and 30.1 ml ± 48.5 ml (0.52% ± 0.79%) for limbBF volume. A significant linear correlation between absolute and relative leg volume differences and the difference of exact day time of measurement between the two study visits was found (P < .001). A therefore determined time-correction formula permitted further improvement of CVW. Conclusions Leg volume changes can be reliably assessed by optoelectronic leg volumetry at a single time point and over a 3 weeks' time period. However, volumetry results are biased by orthostatic and daytime-related volume changes. The bias for day-time related volume changes can be minimized by a time-correction formula

    Potential effects of warmer worms and vectors on onchocerciasis transmission in West Africa

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    Development times of eggs, larvae and pupae of vectors of onchocerciasis (Simulium spp.) and of Onchocerca volvulus larvae within the adult females of the vectors decrease with increasing temperature. At and above 25C,the parasite could reach its infective stage in less than 7 days when vectors could transmit after only two gonotrophic cycles. After incorporating exponential functions for vector development into a novel blackfly population model, it was predicted that fly numbers in Liberia and Ghana would peak at air temperatures of 29C and 34C, about 3C and 7C above current monthly averages, respectively; parous rates of forest flies (Liberia) would peak at 298C and of savannah flies (Ghana) at 308C. Small temperature increases (less than 28C) might lead to changes in geographical distributions of different vector taxa. When the new model was linked to an existing framework for the population dynamics of onchocerciasis in humans and vectors, transmission rates and worm loads were projected to increase with temperature to at least 338C. By contrast, analyses of field data on forest flies in Liberia and savannah flies in Ghana, in relation to regional climate change predictions, suggested, on the basis of simple regressions, that 13–41% decreases in fly numbers would be expected between the present and before 2040. Further research is needed to reconcile these conflicting conclusions

    The Fetal Hypothalamus Has the Potential to Generate Cells with a Gonadotropin Releasing Hormone (GnRH) Phenotype

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    Neurospheres (NS) are colonies of neural stem and precursor cells capable of differentiating into the central nervous system (CNS) cell lineages upon appropriate culture conditions: neurons, and glial cells. NS were originally derived from the embryonic and adult mouse striatum subventricular zone. More recently, experimental evidence substantiated the isolation of NS from almost any region of the CNS, including the hypothalamus. Here we report a protocol that enables to generate large quantities of NS from both fetal and adult rat hypothalami. We found that either FGF-2 or EGF were capable of inducing NS formation from fetal hypothalamic cultures, but that only FGF-2 is effective in the adult cultures. The hypothalamic-derived NS are capable of differentiating into neurons and glial cells and most notably, as demonstrated by immunocytochemical detection with a specific anti-GnRH antibody, the fetal cultures contain cells that exhibit a GnRH phenotype upon differentiation. This in vitro model should be useful to study the molecular mechanisms involved in GnRH neuronal differentiation

    Tissue specific characteristics of cells isolated from human and rat tendons and ligaments

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    <p>Abstract</p> <p>Background</p> <p>Tendon and ligament injuries are common and costly in terms of surgery and rehabilitation. This might be improved by using tissue engineered constructs to accelerate the repair process; a method used successfully for skin wound healing and cartilage repair. Progress in this field has however been limited; possibly due to an over-simplistic choice of donor cell. For tissue engineering purposes it is often assumed that all tendon and ligament cells are similar despite their differing roles and biomechanics. To clarify this, we have characterised cells from various tendons and ligaments of human and rat origin in terms of proliferation, response to dexamethasone and cell surface marker expression.</p> <p>Methods</p> <p>Cells isolated from tendons by collagenase digestion were plated out in DMEM containing 10% fetal calf serum, penicillin/streptomycin and ultraglutamine. Cell number and collagen accumulation were by determined methylene blue and Sirius red staining respectively. Expression of cell surface markers was established by flow cytometry.</p> <p>Results</p> <p>In the CFU-f assay, human PT-derived cells produced more and bigger colonies suggesting the presence of more progenitor cells with a higher proliferative capacity. Dexamethasone had no effect on colony number in ACL or PT cells but 10 nM dexamethasone increased colony size in ACL cultures whereas higher concentrations decreased colony size in both ACL and PT cultures. In secondary subcultures, dexamethasone had no significant effect on PT cultures whereas a stimulation was seen at low concentrations in the ACL cultures and an inhibition at higher concentrations. Collagen accumulation was inhibited with increasing doses in both ACL and PT cultures. This differential response was also seen in rat-derived cells with similar differences being seen between Achilles, Patellar and tail tendon cells. Cell surface marker expression was also source dependent; CD90 was expressed at higher levels by PT cells and in both humans and rats whereas D7fib was expressed at lower levels by PT cells in humans.</p> <p>Conclusion</p> <p>These data show that tendon & ligament cells from different sources possess intrinsic differences in terms of their growth, dexamethasone responsiveness and cell surface marker expression. This suggests that for tissue engineering purposes the cell source must be carefully considered to maximise their efficacy.</p

    Automated Detection of External Ventricular and Lumbar Drain-Related Meningitis Using Laboratory and Microbiology Results and Medication Data

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    OBJECTIVE: Monitoring of healthcare-associated infection rates is important for infection control and hospital benchmarking. However, manual surveillance is time-consuming and susceptible to error. The aim was, therefore, to develop a prediction model to retrospectively detect drain-related meningitis (DRM), a frequently occurring nosocomial infection, using routinely collected data from a clinical data warehouse. METHODS: As part of the hospital infection control program, all patients receiving an external ventricular (EVD) or lumbar drain (ELD) (2004 to 2009; n = 742) had been evaluated for the development of DRM through chart review and standardized diagnostic criteria by infection control staff; this was the reference standard. Children, patients dying <24 hours after drain insertion or with <1 day follow-up and patients with infection at the time of insertion or multiple simultaneous drains were excluded. Logistic regression was used to develop a model predicting the occurrence of DRM. Missing data were imputed using multiple imputation. Bootstrapping was applied to increase generalizability. RESULTS: 537 patients remained after application of exclusion criteria, of which 82 developed DRM (13.5/1000 days at risk). The automated model to detect DRM included the number of drains placed, drain type, blood leukocyte count, C-reactive protein, cerebrospinal fluid leukocyte count and culture result, number of antibiotics started during admission, and empiric antibiotic therapy. Discriminatory power of this model was excellent (area under the ROC curve 0.97). The model achieved 98.8% sensitivity (95% CI 88.0% to 99.9%) and specificity of 87.9% (84.6% to 90.8%). Positive and negative predictive values were 56.9% (50.8% to 67.9%) and 99.9% (98.6% to 99.9%), respectively. Predicted yearly infection rates concurred with observed infection rates. CONCLUSION: A prediction model based on multi-source data stored in a clinical data warehouse could accurately quantify rates of DRM. Automated detection using this statistical approach is feasible and could be applied to other nosocomial infections

    Autophagy Gene Variant IRGM −261T Contributes to Protection from Tuberculosis Caused by Mycobacterium tuberculosis but Not by M. africanum Strains

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    The human immunity-related GTPase M (IRGM) has been shown to be critically involved in regulating autophagy as a means of disposing cytosolic cellular structures and of reducing the growth of intracellular pathogens in vitro. This includes Mycobacterium tuberculosis, which is in agreement with findings indicating that M. tuberculosis translocates from the phagolysosome into the cytosol of infected cells, where it becomes exposed to autophagy. To test whether IRGM plays a role in human infection, we studied IRGM gene variants in 2010 patients with pulmonary tuberculosis (TB) and 2346 unaffected controls. Mycobacterial clades were classified by spoligotyping, IS6110 fingerprinting and genotyping of the pks1/15 deletion. The IRGM genotype −261TT was negatively associated with TB caused by M. tuberculosis (OR 0.66, CI 0.52–0.84, Pnominal 0.0009, Pcorrected 0.0045) and not with TB caused by M. africanum or M. bovis (OR 0.95, CI 0.70–1.30. P 0.8). Further stratification for mycobacterial clades revealed that the protective effect applied only to M. tuberculosis strains with a damaged pks1/15 gene which is characteristic for the Euro-American (EUAM) subgroup of M. tuberculosis (OR 0.63, CI 0.49–0.81, Pnominal 0.0004, Pcorrected 0.0019). Our results, including those of luciferase reporter gene assays with the IRGM variants −261C and −261T, suggest a role for IRGM and autophagy in protection of humans against natural infection with M. tuberculosis EUAM clades. Moreover, they support in vitro findings indicating that TB lineages capable of producing a distinct mycobacterial phenolic glycolipid that occurs exclusively in strains with an intact pks1/15 gene inhibit innate immune responses in which IRGM contributes to the control of autophagy. Finally, they raise the possibility that the increased frequency of the IRGM −261TT genotype may have contributed to the establishment of M. africanum as a pathogen in the West African population

    Prospective assessment of Y-chromosome microdeletions and reproductive outcomes among infertile couples of Japanese and African origin

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    BACKGROUND: To compare the frequency of Y-chromosome microdeletions in Japanese and African azoospermic and oligozoospermic men and describe embryo characteristics and reproductive outcome following in vitro fertilization (IVF) with intracytoplasmic sperm injection (ICSI). METHODS: Our study was performed prospectively at two centers, a private IVF clinic and a university hospital. Japanese and African (Tanzanian) men with nonobstructive azoospermia (NOA) and oligozoospermia (concentration < 5 × 10(6 )/ml) were evaluated for Y-chromosome microdeletions (n = 162). Of the 47 men with NOA, 26 were Japanese and 21 were Africans. Of the 115 men with oligozoospermia, 87 were Japanese and 28 were Africans. Reproductive outcomes of patients with Y-chromosome microdeletions were then compared with those of 19 IVF+ICSI cycles performed on couples with Y-chromosome intact males/tubal factor infertility which served as a control group. RESULTS: Seven azoospermic and oligozoospermic patients had Y-chromosome deletions; the total number of deletions in the AZFc region was five. There was only one deletion in the AZFa region and one complete deletion involving all three regions (AZFa, b, and c) within AZF. In our study population, microdeletion frequency among Japanese men was 6.2% (95% CI, 4.25% – 14.45%), whereas no deletions were identified in the African group (95% CI, 0.0% – 7.27%). The difference between the two groups was not statistically significant, however. Embryos derived from ICSI utilizing sperm with Y-chromosome microdeletion showed reduced rates of fertilization, blastocyst development, implantation, and pregnancy compared to the Y-chromosome intact group, although these observed differences were not statistically significant. CONCLUSION: The observed frequency of Y-chromosome microdeletion was 6.2% among Japanese azoospermic and oligozoospermic males; no microdeletions were identified among our African study patients. In this population of couples undergoing IVF+ICSI, there was no statistically significant difference in embryo characteristics or pregnancy outcome between patients with Y-chromosome microdeletion and those with an intact Y-chromosome

    Patient-provider interaction from the perspectives of type 2 diabetes patients in Muscat, Oman: a qualitative study

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    <p>Abstract</p> <p>Background</p> <p>Patients' expectations and perceptions of the medical encounter and interactions are important tools in diabetes management. Some problems regarding the interaction during encounters may be related to a lack of communication skills on the part of either the physician or the patient.</p> <p>This study aimed at exploring the perceptions of type 2 diabetes patients regarding the medical encounters and quality of interactions with their primary health-care providers.</p> <p>Methods</p> <p>Four focus group discussions (two women and two men groups) were conducted among 27 purposively selected patients (13 men and 14 women) from six primary health-care centres in Muscat, Oman. Qualitative content analysis was applied.</p> <p>Results</p> <p>The patients identified some weaknesses regarding the patient-provider communication like: unfriendly welcoming; interrupted consultation privacy; poor attention and eye contact; lack of encouraging the patients to ask questions on the providers' side; and inability to participate in medical dialogue or express concerns on the patients' side. Other barriers and difficulties related to issues of patient-centeredness, organization of diabetes clinics, health education and professional competency regarding diabetes care were also identified.</p> <p>Conclusion</p> <p>The diabetes patients' experiences with the primary health-care providers showed dissatisfaction with the services. We suggest appropriate training for health-care providers with regard to diabetes care and developing of communication skills with emphasis on a patient-centred approach. An efficient use of available resources in diabetes clinics and distributing responsibilities between team members in close collaboration with patients and their families seems necessary. Further exploration of the providers' work situation and barriers to good interaction is needed. Our findings can help the policy makers in Oman, and countries with similar health systems, to improve the quality and organizational efficiency of diabetes care services.</p

    Hyperoxia increases the uptake of 5-fluorouracil in mammary tumors independently of changes in interstitial fluid pressure and tumor stroma

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    <p>Abstract</p> <p>Background</p> <p>Hypoxia is associated with increased resistance to chemo- and radiation-therapy. Hyperoxic treatment (hyperbaric oxygen) has previously been shown to potentiate the effect of some forms of chemotherapy, and this has been ascribed to enhanced cytotoxicity or neovascularisation. The aim of this study was to elucidate whether hyperoxia also enhances any actual uptake of 5FU (5-fluorouracil) into the tumor tissue and if this can be explained by changes in the interstitium and extracellular matrix.</p> <p>Methods</p> <p>One group of tumor bearing rats was exposed to repeated hyperbaric oxygen (HBO) treatment (2 bar, pO<sub>2 </sub>= 2 bar, 4 exposures à 90 min), whereas one group was exposed to one single identical HBO treatment. Animals housed under normal atmosphere (1 bar, pO<sub>2 </sub>= 0.2 bar) served as controls. Three doses of 5FU were tested for dose response. Uptake of [<sup>3</sup>H]-5FU in the tumor was assessed, with special reference to factors that might have contributed, such as interstitial fluid pressure (P<sub>if</sub>), collagen content, oxygen stress (measured as malondialdehyd levels), lymphatics and transcapillary transport in the tumors.</p> <p>Results</p> <p>The uptake of the cytostatic agent increases immediately after a single HBO treatment (more than 50%), but not 24 hours after the last repeated HBO treatment. Thus, the uptake is most likely related to the transient increase in oxygenation in the tumor tissue. Factors like tumor P<sub>if </sub>and collagen content, which decreased significantly in the tumor interstitium after repeated HBO treatment, was without effect on the drug uptake.</p> <p>Conclusion</p> <p>We showed that hyperoxia increases the uptake of [<sup>3</sup>H]-5FU in DMBA-induced mammary tumors <it>per se</it>, independently of changes in P<sub>if</sub>, oxygen stress, collagen fibril density, or transendothelial transport alone. The mechanism by which such an uptake occur is still not elucidated, but it is clearly stimulated by elevated pO<sub>2</sub>.</p
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