20 research outputs found
Examining the Relationship of Clinical and Laboratory Parameters With Infectiousness to Phlebotomus perniciosus and Its Potential Infectivity in Dogs With Overt Clinical Leishmaniasis
Infected dogs are considered the main domestic animal reservoirs for Leishmania
infantum parasite. Infectiousness to competent phlebotomine vectors has been
associated with many factors, the main being the severity of the disease exhibited by
infected dogs. This study examines the relationship between different clinical parameters
and the infectiousness to colonized Phlebotomus perniciosus sand flies having a blood
meal on dogs. Data obtained in the present study come from an untreated group
of Leishmania sick dogs submitted to xenodiagnosis for the evaluation of a spot on
insecticide solution. Seventeen dogs were diagnosed as affected by leishmaniasis
through clinical examination, immunofluorescence antibody test (IFAT) serology, and
loop-mediated isothermal amplification (LAMP). The disease severity (clinical score)
was staged by using a numeric value derived from eight clinical and parasitological
parameters. Xenodiagnosis was performed on caged dogs exposed for 1.5 h to sand-fly
bites. The following parameters related to sand flies were examined: blood feeding
(% of blood engorged females), promastigote detection (% of promastigote-positive
sand flies), promastigote burden, and the promastigote stage maturation (potential
transmissibility rate). Statistical relationship between the clinical score and entomological
parameters was investigated, as well as the possible correlation between each clinical
and laboratory parameters and sand fly infection/infectivity. The severity of clinical score
may influence the blood feeding by, and the probability of promastigote detection in,
sand flies; skin lesions seem to be the main factor that influences the rate of blood
feeding. Promastigote burden is related to IFAT titer, skin lesions, and clinical score. All
entomological parameters are strongly related among them. This study confirms that
both P. perniciosus infection and infectivity are influenced by a dog’s clinical condition
Uniform and concentrated read disturb effects in mid-1X TLC NAND flash memories for enterprise solid state drives
The read disturb is one of the most important issues in TLC NAND Flash memories since their usage model is predominantly based on read-intensive applications. The state-of-the-art testing and qualification of the memories against this issue is performed by uniformly stressing the memory blocks with same amount of reads. However, by analyzing several workloads, it appears that the read operations are mostly concentrated in specific page regions. In this work, we characterize the different behavior of a mid-1X TLC NAND Flash under uniform and concentrated read disturb. The results are used to speculate the implications of the workload usage model on the reliability of enterprise Solid State Drives using different error correction strategies and data management policies
Morpho-Functional Characterisation of the Rat Ventral Caudal Nerve in a Model of Axonal Peripheral Neuropathy
Peripheral Neuropathies (PN) are common conditions whose treatment is still lacking in most cases. Animal models are crucial, but experimental procedures should be refined in some cases. We performed a detailed characterization of the ventral caudal nerve to contribute to a more effective assessment of axonal damage in future PN studies. PN was induced via weekly systemic injection of a neurotoxic drug (paclitaxel); we compared the control and PN-affected rats, performing serial neurophysiological evaluations of the caudal nerve for its entire length. On the same nerve portions, we performed light microscopy and ultrastructural pathological observations to assess the severity of damage and verify the integrity of the surrounding structures. Neurophysiological and morphological analyses confirmed that a severe axonopathy had ensued in the PN group, with a length-dependent modality, matching morphological observations. The site of neurophysiological recording (e.g., distance from the base of the tail) was critical for achieving useful data. A flexible experimental paradigm should be considered in animal studies investigating axonal PN, particularly if the expected severity is relevant; the mid-portion of the tail might be the most appropriate site: there damage might be remarkable but neither as extreme as at the tip of the tail nor as mild as at the base of the tail
EGFR, KRAS, BRAF, and PIK3CA characterization in squamous cell anal cancer
Background: Combined chemoradiation therapy is the gold standard in the treatment of squamous cell anal cancer (SCAC). However, even if the response rate is very high, many patients eventually relapse or experience a recurrence, thus requiring an invasive surgical procedure that has severe side effects. Most SCAC tumors overexpress epidermal growth factor receptor (EGFR); therefore, it is reasonable to consider anti-EGFR drugs as a new treatment option, as demonstrated by anecdotal reports. Promising results obtained in other solid tumors, both squamous and non-squamous, have revealed that an increase in the EGFR gene copy number may predict the efficacy of anti-EGFR therapies, while the presence of mutations in downstream members of the EGFR pathway may confer resistance. These markers have been only sporadically considered in SCAC.
Methods: We investigated the status of the EGFR gene using FISH and examined KRAS, BRAF, and PIK3CA hot-spots mutations using sequencing analysis in a cohort of 84 patients affected by SCAC.
Results: Twenty-eight patients (34%) showed an increase in EGFR gene copy number due to amplification (4%) or to polysomy (30%). KRAS and PIK3CA gene mutations were found in 4 (5%) and 13 patients (16%), respectively. No mutations were found in the BRAF gene.
Conclusions: The characterization of the EGFR pathway may help in identifying different subgroups of SCAC that have specific molecular features, which may have implications in what targeted therapies are used to treat each patient. Histol Histopathol 29, 513-521 (2014
Age-related changes in the function and structure of the peripheral sensory pathway in mice
This study is aimed at describing the changes occurring in the entire peripheral nervous system sensory pathway along a 2-year observation period in a cohort of C57BL/6 mice. The neurophysiological studies evidenced significant differences in the selected time points corresponding to childhood, young adulthood, adulthood, and aging (i.e., 1, 7, 15, and 25\ua0months of age), with a parabolic course as function of time. The pathological assessment allowed to demonstrate signs of age-related changes since the age of 7\ua0months, with a remarkable increase in both peripheral nerves and dorsal root ganglia at the subsequent time points. These changes were mainly in the myelin sheaths, as also confirmed by the Rotating-Polarization Coherent-Anti-stokes-Raman-scattering microscopy analysis. Evident changes were also present at the morphometric analysis performed on the peripheral nerves, dorsal root ganglia neurons, and skin biopsies. This extensive, multimodal characterization of the peripheral nervous system changes in aging provides the background for future mechanistic studies allowing the selection of the most appropriate time points and readouts according to the investigation aims
Eight novel mutations in SPG4 in a large sample of patients with hereditary spastic paraplegia.
BACKGROUND: Hereditary spastic paraplegia (HSP) is a group of genetically heterogeneous disorders characterized by progressive spasticity of the lower limbs. Mutations in the SPG4 gene, which encodes spastin protein, are responsible for up to 45% of autosomal dominant cases. OBJECTIVE: To search for disease-causing mutations in a large series of Italian patients with HSP. DESIGN: Samples of DNA were analyzed by direct sequencing of all exons in SPG4. Samples from a subset of patients were also analyzed by direct sequencing of all exons in SPG3A, SPG6, SPG10, and SPG13. SETTING: Molecular testing facility in Italy. PATIENTS: Sixty unrelated Italian patients with pure (n = 50) and complicated (n = 10) HSP. MAIN OUTCOME MEASURES: Mutations in SPG4, SPG3A, SPG6, SPG10, and SPG13. RESULTS: We identified 12 different mutations, 8 of which were novel, in 13 patients. No mutations of any of the other HSP genes tested were found in 15 patients with sporadic pure HSP who did not have mutations in the SPG4 gene. CONCLUSIONS: The overall rate of mutation in the SPG4 gene within our sample was 22%, rising to 26% when only patients with pure HSP were considered. The negative result obtained in 15 patients without mutations in SPG4 in whom 4 other genes were analyzed (SPG3A, SPG6, SPG10, and SPG13) indicate that these genes are not frequently mutated in sporadic pure HSP.Comparative StudyJournal ArticleResearch Support, N.I.H. ExtramuralResearch Support, Non-U.S. Gov'tinfo:eu-repo/semantics/publishe