Raman spectrometry appears to be an opportunity to perform rapid tests in microbiological diagnostics as it provides phenotype-related information from single bacterial cells thus holding the promise ...of direct analysis of clinical specimens without any time-consuming growth phase. Here, we demonstrate the feasibility of a rapid antibiotic-susceptibility determination based on the use of Raman spectra acquired on single bacterial cells. After a two-hour preculture step, one susceptible and two resistant E. coli strains were incubated, for only two hours, in the presence of different bactericidal antibiotics (gentamicin, ciprofloxacin, amoxicillin) in a range of concentrations that included the clinical breakpoints used as references in microbial diagnostic. Spectra were acquired and processed to isolate spectral modifications associated with the antibiotic effect. We evidenced an "antibiotic effect signature" which is expressed with specific Raman peaks and the coexistence of three spectral populations in the presence of antibiotic. We devised an algorithm and a test procedure that overcome single-cell heterogeneities to estimate the MIC and determinate the susceptibility phenotype of the tested bacteria using only a few single-cell spectra in four hours only if including the preculture step.
The aim of this study was to evaluate the impact of carbapenem-resistant K. pneumoniae bloodstream infections on mortality. During the study period 42, 68 and 120 patients were identified with ...carbapenem-resistant, extended-spectrum b-lactamase producers (ESBL) and susceptible K. pneumoniae bloodstream infections, respectively. Patients with carbapenem-resistant K. pneumoniae had higher rates of prior antimicrobial exposure, other nosocomial infections, and use of invasive devices. Infection-related mortality was 48% for carbapenem-resistant, 22% for ESBL producers and 17% for susceptible K. pneumoniae. Independent risk factors for infection-related mortality were Pitt bacteraemia score, Charlson score and carbapenem resistance.
Solitary trajectories of analytic vector fields Le Gal, O.
Revista de la Real Academia de Ciencias Exactas, Físicas y Naturales. Serie A, Matemáticas,
10/2019, Volume:
113, Issue:
4
Journal Article
Peer reviewed
A trajectory
γ
of an analytic vector fields
ξ
is said to be solitary, if
γ
is asymptotic to a formal curve and can be isolated from any other trajectory of
ξ
by a finite sequence of point centered ...blow ups. We prove that the collection of all solitary trajectories generates a polynomially bounded o-minimal structure.
The American cockroach, Periplaneta americana, provides a successful model for the study of legged locomotion. Sensory regulation and the relative importance of sensory feedback vs. central control ...in animal locomotion are key aspects in our understanding of locomotive behavior. Here we introduce the cockroach model and describe the basic characteristics of the neural generation and control of walking and running in this insect. We further provide a brief overview of some recent studies, including mathematical modeling, which have contributed to our knowledge of sensory control in cockroach locomotion. We focus on two sensory mechanisms and sense organs, those providing information related to loading and unloading of the body and the legs, and leg-movement-related sensory receptors, and present evidence for the instrumental role of these sensory signals in inter-leg locomotion control. We conclude by identifying important open questions and indicate future perspectives.
Reproductive failure associated with heat stress is a well-known phenomenon. The mechanism involved in this failure is not clearly understood. In order to test a possible direct effect of heat stress ...on ovarian function, 36 White Leghorn laying hens were housed in individual cages in 2 temperature- and light-controlled rooms (n = 18). At 31 wk of age, one group was exposed daily for 12 h to high temperature (42 ± 3°C), and the second group was maintained under thermoneutral conditions (24 to 26°C) and served as control. Body temperature, feed intake, egg production, and egg weight were recorded daily; heparinized blood samples were drawn every 3 d for plasma hormonal level of luteinizing hormone, follicular stimulating hormone, progesterone, 17ss-estradiol, and testosterone. Six days after exposure half of the birds in each group were killed, and the ovary and oviduct were weighed and preovulatory follicles removed and extracted for mRNA of Cytochrome P 450 aromatase, 17-α hydroxylase. The same procedure was repeated 9 d later with the rest of the birds. Short and long heat exposure caused significant hyperthermia and reduction of egg production, egg weight, ovarian weight, and the number of large follicles. In addition, a significant reduction in plasma progesterone and testosterone was detected 2 d after exposing the birds to heat stress, and plasma 17ss-estradiol was significantly reduced 14 d after initiation of heat stress. Short exposure to heat stress caused significant reduction in mRNA expression of cytochrome P450 17-α hydroxylase, exposing the birds to long-term heat stress caused significant reduction in expression of mRNA of both steroidogenic enzymes. No significant change was found in plasma luteinizing hormone and follicular stimulating hormone levels during the entire experimental period. We suggest a possible direct effect of heat stress on ovarian function.
Background and purpose
The main aim of the study was to document the occurrence and evolution of post‐stroke spasticity (PSS). The secondary goal was to identify predictors for increases and ...decreases in PSS rates during 12 months of subsequent follow‐up.
Methods
In a longitudinal, multicenter, prospective cohort study, assessments were done at 7 days (V1), 6 months (V2), and 12 months (V3) after stroke onset. A total of 307 consecutive patients from four comprehensive stroke centers with the first‐ever stroke of carotid origin and the presence of motor deficit at day 7 were included. The demographic data, baseline characteristics, Barthel index, degree and pattern of paresis and muscle tone were evaluated and recorded. Spasticity was assessed using the modified Ashworth scale.
Results
Spasticity was present in 45.0% of patients at V1, in 49.5% at V2, and in 43.2% at V3. A significant number of patients experienced changes in spasticity between visits: increased/new occurrence of spasticity in 32.5% (V1 and V2) and in 13.6% (V2 and V3) of patients; decreased occurrence/disappearance of spasticity in 18.5% (V1 and V2) and in 18.3% (V2 and V3) of patients. The number of patients with severe spasticity increased throughout the year, from 2.6% to 13.0% (V2) and 12.5% (V3).
Conclusions
Spasticity developed in almost half of the included patients. The degree of spasticity often changed over time, in both directions. The rate of severe spasticity increased during the first year, with the maximum at 6 months following stroke onset.
Disruption of sensory inputs from cockroach chordotonal organs by Pymethrozine injection affects spatial (Left and A) but not temporal (B) gait properties. Display omitted
Ensembles of neuronal ...networks and sensory pathways participate in controlling the kinematic and dynamic parameters of animal movement necessary to achieve motor coordination. Determining the relative contribution of proprioceptive feedback is essential for understanding how animals sustain stable, coordinated locomotion in complex natural environments. Here, we focus on the role of chordotonal organs (COs), proprioceptors found in insect legs, in the spatial and temporal regulation of walking. We compare gait parameters of intact cockroaches (Periplaneta americana) and sensory-impaired ones, injected with pymetrozine, a chemical previously shown to abolish CO function in locusts. We verify that afferent CO activity in pymetrozine-treated cockroaches is inhibited, and analyze the effect of this sensory deprivation on inter-leg coordination. We find significant changes in tarsi placement and leg path trajectories after pymetrozine treatment. Leg touchdown accuracy, measured from relative tarsi positions of adjacent legs, is reduced in treated animals. Interestingly, despite poorer spatial coordination in both stance and swing, temporal properties of the gait remain largely the same as in the intact preparations, apart from changes in ipsilateral phase differences between front and middle legs. These findings provide insights into the role of COs in insect gait control and establish pymetrozine as a useful tool for further studies of insect locomotion.
The Na+-K+-ATPase, localized in the basolateral membrane of enterocytes plays a major role in nutrient transport in the small intestine by transferring K+ ions into and Na+ out of the cell. Within ...the enterocyte, homeostasis is maintained by active exclusion of Na from the cell by the Na+,K+-adenosine triphosphatase (ATPase) or sodium pump. Because much of the intestinal nutrient transport is by Na cotransporters, Na+,K+-ATPase may be used to evaluate nutrient uptake. In this study, nutrient transport was evaluated by determining expression and activity of Na+-K+-ATPase in the jejunum of chicks fed diets with different concentrations of Na. Expression of the chicken Na+-K+-ATPase gene was examined following isolation of an 1,140 bp cDNA fragment of the alpha-subunit using a reverse transcription (RT)-PCR reaction with specific primers. This fragment was sequenced and showed 95 to 98% homology with the mammalian alpha-subunit of the Na+-K+-ATPase genes. This cDNA fragment was used as a specific probe in Northern blot hybridization for determination of expression in the chicken jejunum. Expression of mRNA of Na+-K+-ATPase was enhanced at low dietary Na but was unchanged at high dietary Na concentrations. In contrast, activity of the enzyme was low with low dietary Na and unchanged at high dietary Na. The Vmax of the Na+-K+-ATPase was unchanged, but affinity was altered by dietary Na concentrations. Thus, determination of expression and activity of intestinal Na+-K+-ATPase allows clearer understanding of changes in intestinal uptake due to dietary Na.
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