Prvi izveštaj o rasprostranjenosti i kliničkoj slici infekcije mačaka sa Bartonella henselae na području Novog Sada

Cat Scratch Disease (CSD) is an infective disease of animals and humans caused with Bartonella henselae. Prevalence of infection varies between 0 and 68% depending on different population of cats and geographical region. Naturally infected cats are often clinically healthy and are inapparent germ carriers. In this investigation 40 cats from the area of Novi Sad were analyzed. After the epidemiological questionnaire was made, all cats were clinically investigated. To determine the presence of specific antibodies of class G on Bartonella henselae the method of indirect immunofluorescence was used. For the first time in Serbia, in the area of Novi Sad municipality the infection caused by Bartonella henselae in the population of cats was detected. Prevalence of specific antibodies of class IgG on Bartonella henselae antigen in the population of cats was 57%. The most common clinical manifestations in seropositive cats were gingivitis and lymphoadenopathy.Bolest mačijeg ogreba (BMO) je infektivno oboljenje životinja i ljudi izazvano sa Bartonella henselae. Prevalencija infekcije varira u zavisnosti od populacije mačaka i geografskog regiona i kreće se od 0 do 68%. Prirodno inficirane mačke su često klinički zdrave, inaparentne kliconoše. U istraživanje je bilo uključeno 40 mačaka sa područja Novog Sada. Nakon uzimanja epidemiološke ankete, sve mačke su klinički pregledane. Za utvrđivanje prisustva specifičnih antitela klase G na antigene Bartonella henselae korišćen je test indirektne imunofluorescencije. Na geografskom području grada Novog Sada i okoline, po prvi put je u Republici Srbiji, utvrđeno prisustvo infekcije izazvane uzročnikom Bartonella henselae u populaciji mačaka. Prevalencija specifičnih antitela klase IgG na antigen Bartonella henselae u populaciji mačaka iznosila je 57%. Najčešće kliničke manifestacije kod seropozitivnih mačaka bile su gingivitis i limfadenopatija

Seeding hESCs to achieve optimal colony clonality

Human embryonic stem cells (hESCs) and induced pluripotent stem cells (iPSCs) have promising clinical applications which often rely on clonally-homogeneous cell populations. To achieve this, it is important to ensure that each colony originates from a single founding cell and to avoid subsequent merging of colonies during their growth. Clonal homogeneity can be obtained with low seeding densities; however, this leads to low yield and viability. It is therefore important to quantitatively assess how seeding density affects clonality loss so that experimental protocols can be optimised to meet the required standards. Here we develop a quantitative framework for modelling the growth of hESC colonies from a given seeding density based on stochastic exponential growth. This allows us to identify the timescales for colony merges and over which colony size no longer predicts the number of founding cells. We demonstrate the success of our model by applying it to our own experiments of hESC colony growth; while this is based on a particular experimental set-up, the model can be applied more generally to other cell lines and experimental conditions to predict these important timescales

Correlated random walks of human embryonic stem cells in vitro

We perform a detailed analysis of the migratory motion of human embryonic stem cells in two-dimensions, both when isolated and in close proximity to another cell, recorded with time-lapse microscopic imaging. We show that isolated cells tend to perform an unusual locally anisotropic walk, moving backwards and forwards along a preferred local direction correlated over a timescale of around 50 min and aligned with the axis of the cell elongation. Increasing elongation of the cell shape is associated with increased instantaneous migration speed. We also show that two cells in close proximity tend to move in the same direction, with the average separation of m or less and the correlation length of around 25 μm, a typical cell diameter. These results can be used as a basis for the mathematical modelling of the formation of clonal hESC colonies

Human Stem Cells for Ophthalmology: Recent Advances in Diagnostic Image Analysis and Computational Modelling

\ua9 2023, The Author(s).Purpose of Review: To explore the advances and future research directions in image analysis and computational modelling of human stem cells (hSCs) for ophthalmological applications. Recent Findings: hSCs hold great potential in ocular regenerative medicine due to their application in cell-based therapies and in disease modelling and drug discovery using state-of-the-art 2D and 3D organoid models. However, a deeper characterisation of their complex, multi-scale properties is required to optimise their translation to clinical practice. Image analysis combined with computational modelling is a powerful tool to explore mechanisms of hSC behaviour and aid clinical diagnosis and therapy. Summary: Many computational models draw on a variety of techniques, often blending continuum and discrete approaches, and have been used to describe cell differentiation and self-organisation. Machine learning tools are having a significant impact in model development and improving image classification processes for clinical diagnosis and treatment and will be the focus of much future research

Hair follicle dermal cells repopulate the mouse haematopoietic system

Skin and hair follicle stem cell biology is the focus of increasing interest, not least because the adult hair follicle has well defined dermal and epithelial populations that display distinct developmental properties. Recent evidence suggests that a number of adult cell populations have much broader stem cell capabilities than previously thought. To examine whether this applied to the hair follicle, and with a view to developing the follicle as a stem cell model system we investigated whether adult hair follicles were capable of demonstrating haematopoietic stem cell activity. To investigate haematopoietic activity in hair follicles we first used in vitro haematopoietic colony assays. This demonstrated that rodent hair follicle end bulbs as well as micro-dissected dermal papilla and dermal sheath cells actively produced cells of erythroid and myeloid lineages but that follicle epithelial cells did not. As a more stringent test, we then transplanted cultured dermal papilla or dermal sheath cells from transgenically marked donor mice into lethally irradiated recipient mice and observed multi-lineage haematopoietic reconstitution when assayed at intervals of up to one year. Colony assays from bone marrow of primary recipients revealed that over 70% of clonogenic precursors were derived from donor hair follicle cells. When bone marrow from primary mice was harvested and used to repopulate secondary myeloablated recipients, multi-lineage haematopoietic engraftment was observed. Our data show that dermal but not epidermal compartments of the adult hair follicle have much broader stem cell activities than previously described. Although the treatment for many forms of blood disorder, such as leukemia, often requires transplantation of haematopoietic stem cells (HSC), their availability can be rate limiting. Given its easy accessibility, our identification of the hair follicle as a source of extramedullary haematopoietic stem cell activity makes it an attractive potential source for blood stem cell therapeutics and highlights its value as a model system in adult stem cell biology

Urine diverting dry toilets as appropriate adaptation to flood prone areas in cities of developing countries

Living in flood prone areas is a serious challenge for citizen in developing countries, especially in Cameroon. MAFADY Project has been working through identifying best low cost sanitation technologies so as to propose a technology suited to flooded areas of Wouri estuary in Douala. From a defined set of social, financial and technical criteria, analysis of existing sanitation technologies developed in flooded ecosystems was made, and it was found that elevated Urine diverting dry toilets were the one suitable for flood pone areas. A plastic Drum twin pit Urine Diverting Dry Toilet (DUDDT) model was designed and constructed. This paper presents: socio-economic and environmental context of the Wouri estuary, the selected criteria and design parameters, the DUDDT, and finally discuss the construction costs. From analysis, this toilet seems to feet flood prone areas, specifically in urban wetlands of developing countries

Metabolic acclimation to heat stress in farm housed Holstein cows with different body condition scores

The aim of this study was to determine the effects of body condition score to metabolic acclimation in heat stressed Holstein cows. Body condition of cows had no effect on any of the tested parameters during the thermal neutral period, except for the percentage of protein in milk. Heat stress has been demonstrated to have an impact on all the selected parameters, and has been found to be the cause of decreased milk production and quality, increased rectal temperature and respiration rate, decreased glucose, non esterified fatty acids (NEFA) and cholesterol concentration, increased urea and bilirubin concentration, and loss of subcutaneous fat. Obese cows (BCS>4) had less ability of acclimation to heat stress as compared to normal and thin cows (significantly lower production and milk quality, and significantly higher rectal temperature and respiration level in relation to the other groups of cows). Obese cows showed a significantly higher concentration of NEFA and significantly lower glucose during exposure to heat stress. The steady increase in NEFA concentrations and decrease of backfat thickness suggested that fat was used for energy purposes, which significantly increased the heat balance and led to poor acclimation to heat stress in obese cows. Cows with high body condition were at higher risk of developing liver failure and lipidosis (reduced cholesterol and elevated bilirubin concentration) during heat stress, which could be linked with increased concentrations of fatty acids in the blood. This was found with an increased concentration of urea during exposure to heat stress, with significantly higher concentration in obese cows. Using the fat for energy purposes depends on the sensitivity to insulin, which increases during heat stress. Obese cows are naturally less sensitive to insulin and more prone to lipolysis. However, these signs should be the focus of future research.Key words: Body condition score, heat stress, metabolic status, cow

Animal Models for Limbal Stem Cell Deficiency: A Critical Narrative Literature Review

\ua9 2024, The Author(s). This literature review will provide a critical narrative overview of the highlights and potential pitfalls of the reported animal models for limbal stem cell deficiency (LSCD) and will identify the neglected aspects of this research area. There exists significant heterogeneity in the literature regarding the methodology used to create the model and the predefined duration after the insult when the model is supposedly fully fit for evaluations and/or for testing various therapeutic interventions. The literature is also replete with examples wherein the implementation of a specific model varies significantly across different studies. For example, the concentration of the chemical, as well as its duration and technique of exposure in a chemically induced LSCD model, has a great impact not only on the validity of the model but also on the severity of the complications. Furthermore, while some models induce a full-blown clinical picture of total LSCD, some are hindered by their ability to yield only partial LSCD. Another aspect to consider is the nature of the damage induced by a specific method. As thermal methods cause more stromal scarring, they may be better suited for assessing the anti-fibrotic properties of a particular treatment. On the other hand, since chemical burns cause more neovascularisation, they provide the opportunity to tap into the potential treatments for anti-neovascularisation. The animal species (i.e., rats, mice, rabbits, etc.) is also a crucial factor in the validity of the model and its potential for clinical translation, with each animal having its unique set of advantages and disadvantages. This review will also elaborate on other overlooked aspects, such as the anaesthetic(s) used during experiments, the gender of the animals, care after LSCD induction, and model validation. The review will conclude by providing future perspectives and suggestions for further developments in this rather important area of research