Change in spectrum of Brownian fluctuations of optically trapped red blood cells due to malarial infection

We study the properties of single red blood cells (RBCs) held in an optical-tweezers trap. We observe a change in the spectrum of Brownian fluctuations between RBCs from normal and malaria-infected samples. The change, caused by infection-induced structural changes in the cell, appears as a statistical increase in the mean (by 25%) and standard deviation (by 200%) of the corner frequency measured over similar to 100 cells. The increase is observed even though the ensemble of cells being measured consists mostly of cells that do not actually host the parasite, but are from an infected pool. This bystander effect appears to vindicate other observations that infected cells can affect the biomechanical properties of uninfected cells. The change is also observed to be independent of the stage of infection and its duration, highlighting its potential for disease detection. (C) 2010 Society of Photo-Optical Instrumentation Engineers. [DOI: 10.1117/1.3427142].

The ability of prolactin to change the sensitivity of the pituitary of the lactating rat to luteinising hormone releasing hormonein vitro

The ability of prolactin to influence the responsiveness of the lactating rat pituitary to luteinising hormone releasing hormone has been examinedin vitro. The pituitary responsivenessin vivo to luteinising hormone releasing hormone decreased as a function of increase in the lactational stimulus. Prolactin inhibited the spontaneousin vitro release of luteinising hormone and follicle stimulating hormone to a small extent, from the pituitary of lactating rats with the suckling stimulus. However, it significantly inhibited the release of these two hormones from luteinising hormone releasing hormone-stimulated pituitaries. The responsiveness of pituitaries of rats deprived of their litter 24 h earlier, to luteinising hormone releasing hormone was also inhibited by prolactin, although minimal. It was concluded that prolactin could be influencing the functioning of the pituitary of the lactating rat by (a) partially suppressing the spontaneous release of gonadotropin and (b) inhibiting the responsiveness of the pituitary to luteinising hormone releasing hormone.

Ring Resonators and Micro Fluidics: Novel Design for Drug/Disease Detection

MEMS systems are technologically developed from integrated circuit industry to create miniature sensors and actuators. Originally these semiconductor processes and materials were used to build electrical and mechanical systems, but expanded to include biological, optical fluidic magnetic and other systems 12]. Here a novel approach is suggested where in two different fields are integrated via moems, micro fluidics and ring resonators. It is well known at any preliminary stage of disease onset, many physiological changes occur in the body fluids like saliva, blood, urine etc. The drawback till now was that current calibrations are not sensitive enough to detect the minor physiological changes. This is overcome using optical detector techniques 1]. The basic concepts of ring resonators, with slight variations can be used for optical detection of these minute disease markers. A well known fact of ring resonators is that a change in refractive index will trigger a shift in the resonant wavelength 5]. The trigger for the wavelength shift in the case discussed will be the presence of disease agents. To trap the disease agents specific antibody has to be used (e. g. BSA).

Interaction of A beta peptide (1-40) with amino acid aluminium complexes: relevance to Alzheimer's disease

A beta (39-43 aminoacid residues) is the principal peptide component of amyloid deposits in Alzheimer's disease (AD). A beta peptide is derived from the amyloid precursor protein (APP) in which mutations give rise to many forms of familial AD. Aluminium is reported to play a key role in inducing conformational change in the synthetic beta-amyloid peptide (1-40)from alpha-helix to beta-pleated sheet, leading to aggregation and fibrillar formation. We have studied the interaction of amino acid-Al complexes such as D-Asp-Al and L-Glu-Al with A beta(1-40) in TFE/buffer (70% TFE and 30% H2O v/v pH 6.7) mixture using CD spectroscopy. The interaction of either of these amino acid complexes with A beta(1-40) results in loss of alpha-helical content and the peptide is more unstructured compared to free Al3+ in the solution. Our data strongly support the idea, that the Al3+ in the form of aminoacid-Al complexes is more effective in inducing random coil conformation in the A beta peptide than the free Al3+ present in the solution.

Climate change and crop yields in the Indian Cardamom Hills, 1978-2007 CE

In this study we analyzed climate and crop yields data from Indian cardamom hills for the period 1978-2007 to investigate whether there were significant changes in weather elements, and if such changes have had significant impact on the production of spices and plantation crops. Spatial and temporal variations in air temperatures (maximum and minimum), rainfall and relative humidity are evident across stations. The mean air temperature increased significantly during the last 30 years; the greatest increase and the largest significant upward trend was observed in the daily temperature. The highest increase in minimum temperature was registered for June (0.37A degrees C/18 years) at the Myladumpara station. December and January showed greater warming across the stations. Rainfall during the main monsoon months (June-September) showed a downward trend. Relative humidity showed increasing and decreasing trends, respectively, at the cardamom and tea growing tracts. The warming trend coupled with frequent wet and dry spells during the summer is likely to have a favorable effect on insect pests and disease causing organisms thereby pesticide consumption can go up both during excess rainfall and drought years. The incidence of many minor pest insects and disease pathogens has increased in the recent years of our study along with warming. Significant and slight increases in the yield of small cardamom (Elettaria cardamomum M.) and coffee (Coffea arabica), respectively, were noticed in the recent years.; however the improvement of yield in tea (Thea sinensis) and black pepper (Piper nigrum L.) has not been seen in our analysis.

A Generalist Predator Regulating Spread of a Wildlife Disease: Exploring Two Infection Transmission Scenarios

Ecoepidemiology is a well-developed branch of theoretical ecology, which explores interplay between the trophic interactions and the disease spread. In most ecoepidemiological models, however, the authors assume the predator to be a specialist, which consumes only a single prey species. In few existing papers, in which the predator was suggested to be a generalist, the alternative food supply was always considered to be constant. This is obviously a simplification of reality, since predators can often choose between a number of different prey. Consumption of these alternative prey can dramatically change their densities and strongly influence the model predictions. In this paper, we try to bridge the gap and explore a generic ecoepidemiological system with a generalist predator, where the densities of all prey are dynamical variables. The model consists of two prey species, one of which is subject to an infectious disease, and a predator, which consumes both prey species. We investigate two main scenarios of infection transmission mode: (i) the disease transmission rate is predator independent and (ii) the transmission rate is a function of predator density. For both scenarios we fulfil an extensive bifurcation analysis. We show that including a second dynamical prey in the system can drastically change the dynamics of the single prey case. In particular, the presence of a second prey impedes disease spread by decreasing the basic reproduction number and can result in a substantial drop of the disease prevalence. We demonstrate that with efficient consumption of the second prey species by the predator, the predator-dependent disease transmission can not destabilize interactions, as in the case with a specialist predator. Interestingly, even if the population of the second prey eventually vanishes and only one prey species finally remains, the system with two prey species may exhibit different properties to those of the single prey system.

A mobile robot with a two-degree-of-freedom suspension for traversing uneven terrain with minimal slip: Modeling, simulation and experiments

It is known in literature that a wheeled mobile robot (WMR) with fixed length axle will slip on an uneven terrain. One way to avoid wheel slip is to use a torus-shaped wheel with lateral tilt capability which allows the distance between the wheel-ground contact points to change even with a fixed length axle. Such an arrangement needs a two degree-of-freedom (DOF) suspension for the vertical and lateral tilting motion of the wheel. In this paper modeling, simulation, design and experimentation with a three-wheeled mobile robot, with torus-shaped wheels and a novel two DOF suspension allowing independent lateral tilt and vertical motion, is presented. The suspension is based on a four-bar mechanism and is called the double four-bar (D4Bar) suspension. Numerical simulations show that the three-wheeled mobile robot can traverse uneven terrain with low wheel slip. Experiments with a prototype three-wheeled mobile robot moving on a constructed uneven terrain along a straight line, a circular arc and a path representing a lane change, also illustrate the low slip capability of the three-wheeled mobile robot with the D4Bar suspension. (C) 2015 Elsevier Ltd. All rights reserved.

A novel form of human disease with a protease-sensitive prion protein and heterozygosity methionine/valine at codon 129: Case report

Background: Sporadic Creutzfeldt-Jakob disease (sCJD) is a rare neurodegenerative disorder in humans included in the group of Transmissible Spongiform Encephalopathies or prion diseases. The vast majority of sCJD cases are molecularly classified according to the abnormal prion protein (PrPSc) conformations along with polymorphism of codon 129 of the PRNP gene. Recently, a novel human disease, termed "protease-sensitive prionopathy", has been described. This disease shows a distinct clinical and neuropathological phenotype and it is associated to an abnormal prion protein more sensitive to protease digestion. Case presentation: We report the case of a 75-year-old-man who developed a clinical course and presented pathologic lesions compatible with sporadic Creutzfeldt-Jakob disease, and biochemical findings reminiscent of "protease-sensitive prionopathy". Neuropathological examinations revealed spongiform change mainly affecting the cerebral cortex, putamen/globus pallidus and thalamus, accompanied by mild astrocytosis and microgliosis, with slight involvement of the cerebellum. Confluent vacuoles were absent. Diffuse synaptic PrP deposits in these regions were largely removed following proteinase treatment. PrP deposition, as revealed with 3F4 and 1E4 antibodies, was markedly sensitive to pre-treatment with proteinase K. Molecular analysis of PrPSc showed an abnormal prion protein more sensitive to proteinase K digestion, with a five-band pattern of 28, 24, 21, 19, and 16 kDa, and three aglycosylated isoforms of 19, 16 and 6 kDa. This PrPSc was estimated to be 80% susceptible to digestion while the pathogenic prion protein associated with classical forms of sporadic Creutzfeldt-Jakob disease were only 2% (type VV2) and 23% (type MM1) susceptible. No mutations in the PRNP gene were found and genotype for codon 129 was heterozygous methionine/valine. Conclusions: A novel form of human disease with abnormal prion protein sensitive to protease and MV at codon 129 was described. Although clinical signs were compatible with sporadic Creutzfeldt-Jakob disease, the molecular subtype with the abnormal prion protein isoforms showing enhanced protease sensitivity was reminiscent of the "protease-sensitive prionopathy". It remains to be established whether the differences found between the latter and this case are due to the polymorphism at codon 129. Different degrees of proteinase K susceptibility were easily determined with the chemical polymer detection system which could help to detect proteinase-susceptible pathologic prion protein in diseases other than the classical ones.

The Health Impacts of Climate Change: A Study of Cholera in Tanzania

27 p.

Epidemiologia das infecções causadas por Staphylococcus aureus resistente a meticilina com perfil comunitário (CA-MRSA) em pacientes atendidos em um hospital terciário no Rio de Janeiro

O Staphylococcus aureus resistente a meticilina (MRSA) foi inicialmente descrito como um patógeno associado a infecções relacionadas à assistência em saúde; porém, um clone de MRSA, o CA-MRSA emergiu na comunidade e está atualmente incrementando nos hospitais. O objetivo desta tese foi descrever aspectos relacionados com a epidemiologia das infecções por cepas CA-MRSA no Hospital Universitário Pedro Ernesto da Universidade do Estado do Rio de Janeiro (HUPE/UERJ), avaliando especificamente fatores de risco relacionado com as infecções por CA-MRSA. Usando informações das bases de dados do laboratório de microbiologia, da farmácia e da Comissão para Controle da Infecção Hospitalar do HUPE/UERJ foi realizado um estudo retrospectivo de infecções/colonizações por cepas de S. aureus (fevereiro 2005 a Julho 2011). Foi realizado um estudo caso e controle, utilizando como casos os pacientes com infecções por cepas CA-MRSA. Na avaliação da susceptibilidade aos antimicrobianos usados em infecções graves por MRSA (vancomicina, teicoplanina, daptomicina e linezolida), foram determinadas as concentrações inibitórias mínimas (CIM) das amostras por diferentes metodologias (testes de difusão em agar, microdiluição em caldo e E-test). Nas analises das tendências temporais da apresentação dos subtipos de MRSA, usando um critério fenotípico para classificação das cepas MRSA, foi observada uma diminuição do número de cepas de MRSA multirresistente (HA-MRSA) (p<0.05). Também foi observada uma tendência ao aumento de cepas não-multirresistentes (CA-MRSA), mas sem alcançar a significância estatística (p = 0.06) igual que os S. aureus sensíveis a meticilina (MSSA) (p = 0.48). Não houve associação entre o subtipo de MRSA e a mortalidade devida à infecção por cepas MRSA. Uma idade acima de 70 anos (OR: 2.46, IC95%: 0.99 - 6.11), a presença de pneumonia adquirida no hospital (OR: 4.94, IC95%: 1.65 -14.8), a doença pulmonar obstrutiva crônica (OR: 6.09, IC95% 1.16 31.98) e a leucemia (OR: 8.2, IC95%: 1.25 54.7) foram fatores de risco associadas à mortalidade nas infecções por cepas de S. aureus. Usando curvas de Kaplan-Meier, foi observada uma tendência ao aumento da mortalidade em infecções causadas por MSSA na primeira semana, porém sem alcançar significância estatística (p = 0.07). Não foram observadas amostras MRSA com susceptibilidade intermediaria a vancomicina, linezolida, daptomicina ou teicoplanina. A dinâmica das infecções por S. aureus no HUPE/UERJ mudou durante o período de estudo, com menor número de episódios infecciosos causados por cepas de MRSA multirresistentes. Existe uma tendência ao aumento das cepas não-multirresistentes de MRSA entanto que a taxa de infecções por MSSA permaneceu estável no período do estudo. O perfil de resistência dos estafilococos não teve associação com a mortalidade

Determinação do perfil fenotípico e genotípico de amostras de Staphylococus aureus resistentes à meticilina (MRSA) e sensíveis a antibióticos não ß-lactâmicos em cinco hospitais no município do Rio de Janeiro

Staphylococcus aureus resistente à meticilina (MRSA) é um dos principais microrganismos envolvidos nas Infecções relacionadas à Assistência à Saúde (IrAS). Porém, um clone de MRSA, o CA-MRSA, emergiu na comunidade e atualmente vem sendo agente de IrAS. O objetivo desta dissertação é avaliar fenotípica e genotipicamente 111 amostras de Staphylococcus aureus resistentes à meticilina e sensíveis a antibióticos não ß-lactâmicos de pacientes atendidos em cinco hospitais no município do Rio de Janeiro. Utilizando os critérios padronizados pelo CLSI 2012, foram determinadas as susceptibilidades a 11 antimicrobianos pelo método de disco difusão em ágar e concentração inibitória mínima para vancomicina e oxacilina pelo método da microdiluição em caldo. A multirresistência (resistência a 3 ou mais antimicrobianos não ß-lactâmicos) foi observada em 31,5% das amostras, sendo que 53,2% apresentaram resistência ao antimicrobiano clindamicina, uma das opções para o tratamento empírico das infecções de pele/tecidos moles. 86,4% apresentaram concentração inibitória mínima (CIM) para vancomicina ≥ 1,0 g/mL ou seja, elevado percentual de amostras associadas ao fenômeno MIC creep, o qual está associado ao insucesso na terapia antimicrobiana anti-MRSA. Não foi observado até o momento nenhuma amostra com CIM ≥ 4cg/mL para vancomicina, entretanto, já há resistência à linezolida em quatro hospitais do estudo. A tipificação do SCCmec nos permitiu classificar 4,5% das amostras em HA-MRSA e 86,5% em CA-MRSA, nas quais a resistência heterogênea típica à oxacilina foi observada em 57,2%. A toxina de Panton-Valentine (PVL) foi identificada pela metodologia de PCR em 28% das amostras com genótipo CA-MRSA. Os fatores de riscos clássicos, da literatura, relacionados à infecção por HA-MRSA foram também observados nos pacientes com infecção por CA-MRSA portadoras de SCCmec IV e V. No intuito de verificar a existência de similaridades genéticas ou a presença de clone predominante entre as amostras dos cinco hospitais, foi realizada a técnica de eletroforese em gel sob campo pulsado (PFGE) e observou-se diversidade genética assim como a presença de amostras com padrões similares aos clones OSPC (18,5%) e USA400. Não foram encontradas amostras com padrões de eletroforese similares aos clones USA300, USA800 e CEB. É essencial a vigilância da resistência aos antimicrobianos não ß-lactâmicos no CA-MRSA, em especial à vancomicina. A mudança na epidemiologia deste microrganismo vem impactando os padrões característicos dos genótipos limitando os critérios de diferenciação entre eles. Neste contexto, as técnicas moleculares atuam como excelentes ferramentas de caracterização. O conhecimento do patógeno auxilia na elaboração e implementação de medidas preventivas, contribuindo para o controle da doença tanto no ambiente hospitalar quanto na comunidade.

Coral health and disease in the Pacific: vision for action

Shallow coral reefs in the IndoPacific contain the highest diversity of marine organisms in the world, with approximately 1500 described species of fish, over 500 species of scleractinian corals, and an estimated 1-10 million organisms yet to be characterized (Reaka-Kudla et al. 1994). These centers of marine biodiversity are facing significant, multiple threats to reef community and habitat structure and function, resulting in local to wide-scale regional damage. Wilkinson (2004) characterized the major pressures as including (1) global climate change, (2) diseases, plagues and invasive species, (3) direct human pressures, (4) poor governance and lack of political will, and (5) international action or inaction. Signs that the natural plasticity of reef ecosystems has been exceeded in many areas from the effects of environmental (e.g., global climate change) and anthropogenic (e.g., land use, pollution) stressors is evidenced by the loss of 20% of the world’s coral reefs (Wilkinson 2004). Predictions are that another 24% (Wilkinson 2006) are under imminent risk of collapse and an additional 26% are under a longer term threat from reduced fitness, disease outbreaks, and increased mortality. These predictions indicate that the current list of approximately 30-40 fatal diseases impacting corals will expand as will the frequency and extent of “coral bleaching” (Waddell 2005; Wilkinson 2004). Disease and corallivore outbreaks, in combination with multiple, concomitant human disturbances are compromising corals and coral reef communities to the point where their ability to rebound from natural disturbances is being lost.

Field manual for investigating coral disease outbreaks

Coral reefs throughout their circumtropical range are declining at an accelerating rate. Recent predictions indicate that 20% of the world’s reefs have been degraded, another 24% are under imminent risk of collapse, and if current estimates hold, by 2030, 26% of the world’s reefs will be lost (Wilkinson 2004). Recent changes to these ecosystems have included losses of apex predators, reductions of important herbivorous fishes and invertebrates, and precipitous declines in living coral cover, with many reefs now dominated by macroalgae. Causes have been described in broad sweeping terms: global climate change, over-fishing and destructive fishing, land-based sources of pollution, sedimentation, hurricanes, mass bleaching events and disease. Recognition that corals can succumb to disease was first reported in the early 1970’s. Then it was a unique observation, with relatively few isolated reports until the mid 1990’s. Today disease has spread to over 150 species of coral, reported from 65 countries throughout all of the world’s tropical oceans (WCMC Global Coral Disease Database). While disease continues to increase in frequency and distribution throughout the world, definitive causes of coral diseases have remained elusive for the most part, with reef managers not sufficiently armed to combat it.

Diet of the minimal armhook squid (Berryteuthis anonychus) (Cephalopoda: Gonatidae) in the northeast Pacific during spring

The stomach contents of the minimal armhook squid (Berryteuthis anonychus) were examined for 338 specimens captured in the northeast Pacific during May 1999. The specimens were collected at seven stations between 145−165°W and 39−49°N and ranged in mantle length from 10.3 to 102.2 mm. Their diet comprised seven major prey groups (copepods, chaetognaths, amphipods, euphausiids, ostracods, unidentified fish, and unidentified gelatinous prey) and was dominated by copepods and chaetognaths. Copepod prey comprised four genera, and 86% by number of the copepods were from the genus Neocalanus. Neocalanus cristatus was the most abundant prey taxa, composing 50% by mass and 35% by number of the total diet. Parasagitta elegans (Chaetognatha) occurred in more stomachs (47%) than any other prey taxon. Amphipods occurred in 19% of the stomachs but composed only 5% by number and 3% by mass of the total prey consumed. The four remaining prey groups (euphausiids, ostracods, unidentified fish, and unidentified gelatinous prey) together composed <2% by mass and <1% by number of the diet. There was no major change in the diet through the size range of squid examined and no evidence of cannibalism or predation on other cephalopod species.

Disease problems in shrimp sector in Khulna district of Bangladesh: a question of sustainability

Disease is the main restraining factor for the development of shrimp sector in Bangladesh. Both brackish water shrimp bagda (Penaeus monodon) and freshwater prawn golda, (Macrobrachium rosenbergii) farming in Bangladesh have been facing disease problem. A study on disease outbreak in both brackish water and freshwater small-scale shrimp farms (gher) in Khulna district was carried out through interviewing randomly selected 3-5% of shrimp farmers with a structured questionnaire during March to December, 2002. The study showed that 97% bagda farming ghers and 80% golda farming ghers were affected by disease. White spot disease was the severe disease for bagda, whereas, antenna rot was the main disease for freshwater prawn. Change of water and liming were carried out as control measures of disease for bagda shrimp farming, while it was only liming for golda farming. A small number of shrimp farmers (15%) used chemicals for treatment of shrimp diseases. Development of suitable farming technology to prevent disease contamination and innovation of proper treatments for diseases are required to overcome the disease problems for sustainable shrimp farming in Bangladesh.