271 research outputs found
Volatile Urinary Signals of Two Nocturnal Primates, Microcebus murinus and M. lehilahytsara
Mouse lemurs are small, nocturnal, arboreal solitary foragers and are endemic primates of Madagascar. This lifestyle and their high predation risk can explain why mouse lemurs rely heavily on olfaction for intraspecific communication. As they often use urine for this purpose, we investigated dichloromethane extracts of the urine of two mouse lemur species, the gray mouse lemur (Microcebus murinus) and the Godman’s mouse lemur (M. lehilahytsara), using gas-chromatography-mass spectrometry. We detected 977 different volatile compounds of different compound classes in 22 urine extracts obtained from nine M. murinus (four males, five females) and nine M. lehilahytsara (three males, six females) individuals. We compared the volatile profiles of the sexes and species using principal component analyses and discriminant function analyses and detected a significant difference in the urinary profiles of males and females and in the profiles of M. murinus and M. lehilahytsara. These very complex sex- and species-specific signatures could be used for distance communication in the context of species recognition, for mate search and in male-male competition. Our study provides important mechanistic insights into complex chemical signaling pathways in primates that are mirrored, in the case of mouse lemurs, by their extraordinarily rich repertoire of olfactory receptors. The production of highly informative olfactory signals may be complementing the complex acoustic signaling system of these solitary foragers suggesting the existence of a multimodal communication network that should be highly beneficial for any species living in dispersed social networks
Evaluation of the appropriate time period between sampling and analyzing for automated urinalysis
Introduction: Preanalytical specifications for urinalysis must be strictly adhered to avoid false interpretations. Aim of the present study is to examine whether the preanalytical factor ‘time point of analysis’ significantly influences stability of urine samples for urine particle and dipstick analysis.
Materials and methods: In 321 pathological spontaneous urine samples, urine dipstick (Urisys™2400, Combur-10-Test™strips, Roche Diagnostics, Mannheim, Germany) and particle analysis (UF-1000 i™, Sysmex, Norderstedt, Germany) were performed within 90 min, 120 min and 240 min after urine collection.
Results: For urine particle analysis, a significant increase in conductivity (120 vs. 90 min: P < 0.001, 240 vs. 90 min: P < 0.001) and a significant decrease in WBC (120 vs. 90 min P < 0.001, 240 vs. 90 min P < 0.001), RBC (120 vs. 90 min P < 0.001, 240 vs. 90 min P < 0.001), casts (120 vs. 90 min P < 0.001, 240 vs. 90 min P < 0.001) and epithelial cells (120 vs. 90 min P = 0.610, 240 vs. 90 min P = 0.041) were found. There were no significant changes for bacteria. Regarding urine dipstick analysis, misclassification rates between measurements were significant for pH (120 vs. 90 min P < 0.001, 240 vs. 90 min P < 0.001), leukocytes (120 vs. 90 min P < 0.001, 240 vs. 90 min P < 0.001), nitrite (120 vs. 90 min P < 0.001, 240 vs. 90 min P < 0.001), protein (120 vs. 90 min P < 0.001, 240 vs. 90 min P<0.001), ketone (120 vs. 90 min P < 0.001, 240 vs. 90 min P < 0.001), blood (120 vs. 90 min P < 0.001, 240 vs. 90 min P < 0.001), specific gravity (120 vs. 90 min P < 0.001, 240 vs. 90 min P < 0.001) and urobilinogen (120 vs. 90 min, P = 0.031). Misclassification rates were not significant for glucose and bilirubin.
Conclusion: Most parameters critically depend on the time window between sampling and analysis. Our study stresses the importance of adherence to early time points in urinalysis (within 90 min)
Eutergesundheits- und Stoffwechselstatus von Milchkühen in der Frühlaktation - was gibt den Ausschlag: Rasse oder Management?
Der Zeitraum der ansteigenden Milchleistung nach dem Kalben birgt ein höheres Risiko, dass die Tiere an Stoffwechselstörungen oder Mastitis erkranken. Die rechtlichen Regelungen für den ökologischen Landbau verschärfen dieses Risiko durch die Limitierung des Kraftfuttereinsatzes, fordern aber auch von den Landwirten mit Hilfe angepasster Rassen, dieses Problem anzugehen. Die vorliegende Studie zielte auf den Vergleich von zwei verschiedenen Rassen, die unter den gleichen Managementbedingungen gehalten wurden und einem Vergleich von zwei Betrieben, die zwar die gleiche Rasse hielten, sich aber im Management unterschieden. Es sollte geprüft werden ob die Rasse oder das Management entscheidender für den Eutergesundheits- und Stoffwechselstatus der Kühe in den ersten fünf Laktationswochen ist. Die Ergebnisse zeigten einen signifikanten Effekt der Energiebilanz und der Woche der Probenahme auf die getesteten Kriterien zur Einschätzung der Stoffwechselsituation (Fett-Eiweiß-Quotient FEQ, BHB-Konzentration der Milch, Glutamatdehydrogenase, nichtveresterte Fettsäuren). Hinsichtlich des FEQ und der BHB-Konzentration ergaben sich deutliche Effekte des Managements und der Rasse, wobei der managementeffekt deutlicher wurde. Der Zellgehalt des Gesamtgemelks zeigte Unterschiede zwischen den Herden, aber nicht zwischen den Rassen, die unter gleichen Bedingungen gehalten wurden
Real-time PCR detection of the HhaI tandem DNA repeat in pre- and post-patent Brugia malayi infections: a study in Indonesian transmigrants
Background:
Lymphatic filariasis caused by Wuchereria bancrofti or Brugia spp. is a public health problem in developing countries. To monitor bancroftian filariasis infections, Circulating Filarial Antigen (CFA) test is commonly used, but for brugian infections only microfilariae (Mf) microscopy and indirect IgG4 antibody analyses are available. Improved diagnostics for detecting latent infections are required.
Methods:
An optimized real-time PCR targeting the brugian HhaI repeat was validated with plasma from microfilariae negative Mongolian gerbils (jirds) infected with B. malayi. Plasma samples from microfilaremic patients infected with B. malayi or W. bancrofti were used as positive and negative controls, respectively. PCR results of plasma samples from a transmigrant population in a B. malayi endemic area were compared to those of life-long residents in the same endemic area; and to IgG4 serology results from the same population. To discriminate between active infections and larval exposure a threshold was determined by correlation and Receiver-Operating Characteristics (ROC) curve analyses.
Results:
The PCR detected HhaI in pre-patent (56 dpi) B. malayi infected jirds and B. malayi Mf-positive patients from Central Sulawesi, Indonesia. HhaI was also detected in 9/9 elephantiasis patients. In South Sulawesi 87.4% of the transmigrants and life-long residents (94% Mf-negative) were HhaI PCR positive. Based on ROC-curve analysis a threshold for active infections was set to >53 HhaI copies/μl (AUC: 0.854).
Conclusions:
The results demonstrate that the HhaI PCR detects brugian infections with greater sensitivity than the IgG4 test, most notably in Mf-negative patients (i.e. pre-patent or latent infections)
Reductions in microfilaridermia by repeated ivermectin treatment are associated with lower Plasmodium-specific Th17 immune responses in Onchocerca volvulus-infected individuals
Background: 37 million individuals are currently infected with Onchocerca volvulus (O. volvulus), a parasitic nematode that elicits various dermal manifestations and eye damage in man. Disease control is primarily based on distributing ivermectin in mass drug administration (MDA) programmes which aim at breaking transmission by eliminating microfilariae (MF), the worm's offspring. The majority of infected individuals present generalized onchocerciasis, which is characterized by hyporesponsive immune responses and high parasite burden including MF. Recently, in areas that have been part of MDA programmes, individuals have been identified that present nodules but are amicrofilaridermic (a-MF) and our previous study showed that this group has a distinct immune profile. Expanding on those findings we determined the immune responses of O. volvulus-infected individuals to a Plasmodium-derived antigen MSP-1 (merozoite surface protein-1), which is required by the parasite to enter erythrocytes. Methods: Isolated PBMCs from O. volvulus-infected individuals (164 MF+ and 46 a-MF) and non-infected volunteers from the same region (NEN), were stimulated with MSP-1 and the resulting supernatant screened for the presence of IL-5, IL-13, IFN-γ, TNF-α, IL-6, IL-17A and IL-10. These findings were then further analyzed following regression analysis using the covariates MF, ivermectin (IVM) and region. The latter referred to the Central or Ashanti regions of Ghana, which, at the time sampling, had received 8 or 1 round of MDA respectively. Results: IL-5, IL-13 and IFN-γ responses to MSP-1 were not altered between NEN and O. volvulus-infected individuals nor were any associations revealed in the regression analysis. IL-10, IL-6 and TNF-α MSP-1 responses were, however, significantly elevated in cultures from infected individuals. Interestingly, when compared to a-MF individuals, MSP-induced IL-17A responses were significantly higher in MF+ patients. Following multivariable regression analysis these IL-10, IL-6, TNF-α and IL-17A responses were all dominantly associated with the regional covariate. Conclusions: Consequently, areas with a lowered infection pressure due to IVM MDA appear to influence bystander responses to Plasmodium-derived antigens in community members even if they have not regularly participated in the therapy
Histopathological evaluation of Onchocerca volvulus nodules by microscopy and by digital image analysis for the study of macrofilaricidal drug efficacy
BACKGROUND: Novel drugs or drug combinations that kill or permanently sterilize adult
MATERIAL AND METHODS: Two expert microscopists independently assessed 605 nodules by direct microscopy. At least two sections with two different stains hematoxylin & eosin (H&E, APR immunostain) of paraffin-embedded, ethanol-fixed whole-nodule cross-sections were analyzed. After variables were identified prone to observer discrepancies, we performed a second study to compare consolidated results for 100 nodules obtained by the two readers by microscopy and by analysis of scanned, high resolution digital images (20x magnification). The last data set analyzed was a quality panel of 100 nodules that has been previously examined by microscopy, and included additional immunostains for
RESULTS: The degree of agreement between assessors varied for different parameters. Agreement for female worm counts in nodules was approximately 80%, while agreement regarding female worm viability was 98%. There were no major differences observed between results obtained by microscopy or digital images. Good agreement for important parameters was also observed for the nodules of the quality panel.
CONCLUSION: Nodule analysis by experienced microscopists was reproducible with regard to important parameters such as identification of living female worms or detection of normal embryogenesis. Assessments varied more for other parameters, and we recommend continued use of two independent readers for detailed analyzes. Analysis of scanned images provided similar results to direct microscopy. This facilitates training and comparison of nodule findings by readers in different locations. Analysis of high quality digital images that can be viewed remotely should improve the quality and availability of nodule assessments that are primary endpoints for onchocerciasis clinical trials
Dynamical structure factor of the anisotropic Heisenberg chain in a transverse field
We consider the anisotropic Heisenberg spin-1/2 chain in a transverse
magnetic field at zero temperature. We first determine all components of the
dynamical structure factor by combining exact results with a mean-field
approximation recently proposed by Dmitriev {\it et al}., JETP 95, 538 (2002).
We then turn to the small anisotropy limit, in which we use field theory
methods to obtain exact results. We discuss the relevance of our results to
Neutron scattering experiments on the 1D Heisenberg chain compound .Comment: 13 pages, 14 figure
Исследование теплопереноса при воспламенении типичного лесного горючего материала (ветвь хвойного дерева) при воздействии высокотемпературной среды
Объект исследования – ветвь хвойного дерева. Предмет исследования – моделирование теплопереноса в слоистой структуре ветви хвойного дерева при тепловом воздействии от фронта лесного пожара. Исходные данные – теплофизические характеристики хвойного дерева.The object of study is a branch of a coniferous tree. The subject of the study is the modeling of heat transfer in a layered structure of a branch of a coniferous tree under thermal effects from the front of a forest fire. Baseline data - thermophysical characteristics of coniferous wood
Vascular CXCR4 Expression – a Novel Antiangiogenic Target in Gastric Cancer?
BACKGROUND:
G-protein-coupled receptors (GPCRs) are prime candidates for novel cancer prevention and treatment strategies. We searched for differentially expressed GPCRs in node positive gastric carcinomas.
METHODOLOGY/PRINCIPAL FINDINGS:
Differential expression of GPCRs in three node positive vs. three node negative intestinal type gastric carcinomas was analyzed by gene array technology. The candidate genes CXCL12 and its receptor CXCR4 were validated by real-time reverse-transcription polymerase chain reaction in an independent set of 37 gastric carcinomas. Translation was studied by immunohistochemistry in 347 gastric carcinomas using tissue microarrays as well as in 61 matching lymph node metastases. Protein expression was correlated with clinicopathological patient characteristics and survival. 52 GPCRs and GPCR-related genes were up- or down-regulated in node positive gastric cancer, including CXCL12. Differential expression of CXCL12 was confirmed by RT-PCR and correlated with local tumour growth. CXCL12 immunopositivity was negatively associated with distant metastases and tumour grade. Only 17% of gastric carcinomas showed CXCR4 immunopositive tumour cells, which was associated with higher local tumour extent. 29% of gastric carcinomas showed CXCR4 positive tumour microvessels. Vascular CXCR4 expression was significantly associated with higher local tumour extent as well as higher UICC-stages. When expressing both, CXCL12 in tumour cells and CXCR4 in tumour microvessels, these tumours also were highly significantly associated with higher T- and UICC-stages. Three lymph node metastases revealed vascular CXCR4 expression while tumour cells completely lacked CXCR4 in all cases. The expression of CXCL12 and CXCR4 had no impact on patient survival.
CONCLUSIONS/SIGNIFICANCE:
Our results substantiate the significance of GPCRs on the biology of gastric carcinomas and provide evidence that the CXCL12-CXCR4 pathway might be a novel promising antiangiogenic target for the treatment of gastric carcinomas
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