Specific primers for PCR amplification of the ITS1 (ribosomal DNA) of Trypanosoma lewisi

Trypanosoma lewisi is a mild or non-pathogenic parasite of the sub-genus Herpetosoma transmitted by fleas to rats. In a previous study we described pan-trypanosome specific primers TRYP1 which amplify the ITS1 of ribosomal DNA by hybridizing in highly conserved regions of 18S and 5.8S genes. These primers proved to be useful for detecting T. lewisi DNA in laboratory rats, but a recent large scale survey in wild rodents demonstrated a lack of specificity. In the present study, we designed and evaluated mono-specific primers LEW1S and LEW1R, for the detection and identification of T. lewisi by a single-step PCR. These primers were designed inside the highly variable region of the ITS1 sequence of T. lewisi ribosomal DNA. The product size of 220 bp is specific to T. lewisi. The sensitivity limit was estimated between 0.055 and 0.55 pg of DNA per reaction, equivalent to 1–10 organisms per reaction. All the PCR products obtained from 6 different T. lewisi isolates were more than 98% similar with each other and similar to the sequences of T. lewisi already published in Genbank. All DNA of 7 T. lewisi stocks from China gave the specific 220 bp product. We showed that LEW1S and LEW1R primers enabled sensitive detection and identification of T. lewisi infection in laboratory and wild rats. This assay is recommended for monitoring T. lewisi infections in rat colonies or for studying infections in the wild fauna. An absence of cross reaction with human DNA means that these primers can be used to investigate atypical trypanosome infections in humans. Given the risk of T. lewisi infection in human, we believe that these primers will be beneficial for public health diagnosis and rodents investigation programmes.     

Searching for Preclinical Models of Acute Decompensated Heart Failure: a Concise Narrative Overview and a Novel Swine Model

Cardiovascular Drugs and Therapy - Available animal models of acute heart failure (AHF) and their limitations are discussed herein. A novel and preclinically relevant porcine model of decompensated...     

Positive association between cerebral grey matter metabolism and dopamine D2/D3 receptor availability in healthy and schizophrenia subjects: An 18F-fluorodeoxyglucose and 18F-fallypride positron emission tomography study

Abstract

Objectives: Overlapping decreases in extrastriatal dopamine D₂/D₃-receptor availability and glucose metabolism have been reported in subjects with schizophrenia. It remains unknown whether these findings are physiologically related or coincidental.

Methods: To ascertain this, we used two consecutive ¹⁸F-fluorodeoxyglucose and ¹⁸F-fallypride positron emission tomography scans in 19 healthy and 25 unmedicated schizophrenia subjects. Matrices of correlations between ¹⁸F-fluorodeoxyglucose uptake and ¹⁸F-fallypride binding in voxels at the same xyz location and AFNI-generated regions of interest were evaluated in both diagnostic groups.

Results: ¹⁸F-fluorodeoxyglucose uptake and ¹⁸F-fallypride binding potential were predominantly positively correlated across the striatal and extrastriatal grey matter in both healthy and schizophrenia subjects. In comparison to healthy subjects, significantly weaker correlations in subjects with schizophrenia were confirmed in the right cingulate gyrus and thalamus, including the mediodorsal, lateral dorsal, anterior, and midline nuclei. Schizophrenia subjects showed decreased D₂/D₃-receptor availability in the hypothalamus, mamillary bodies, thalamus and several thalamic nuclei, and increased glucose uptake in three lobules of the cerebellar vermis.

Conclusions: Dopaminergic system may be involved in modulation of grey matter metabolism and neurometabolic coupling in both healthy human brain and psychopathology. Hyperdopaminergic state in untreated schizophrenia may at least partly account for the corresponding decreases in grey matter metabolism.     

Three-dimensional architecture of nephrons in the normal and cystic kidney

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Recellularizing of human acellular dermal matrices imaged by high‐definition optical coherence tomography

High‐definition optical coherence tomography (HD‐OCT) permits real‐time 3D imaging of the impact of selected agents on human skin allografts. The real‐time 3D HD‐OCT assessment of (i) the impact on morphological and cellular characteristics of the processing of human acellular dermal matrices (HADMs) and (ii) repopulation of HADMs in vitro by human fibroblasts and remodelling of the extracellular matrix by these cells. Four different skin decellularization methods, Dispase II/Triton X‐100, Dispase II/SDS (sodium dodecyl sulphate), NaCl/Triton X‐100 and NaCl/SDS, were analysed by HD‐OCT. HD‐OCT features of epidermal removal, dermo‐epidermal junction (DEJ) integrity, cellularity and dermal architecture were correlated with reflectance confocal microscopy (RCM), histopathology and immunohistochemistry. Human adult dermal fibroblasts were in vitro seeded on the NaCl/Triton X‐100 processed HADMs, cultured up to 19 days and evaluated by HD‐OCT in comparison with MTT proliferation test and histology. Epidermis was effectively removed by all treatments. DEJ was best preserved after NaCl/Triton X‐100 treatment. Dispase II/SDS treatment seemed to remove all cellular debris in comparison with NaCl/Triton X‐100 but disturbed the DEJ severely. The dermal micro‐architectural structure and vascular spaces of (sub)papillary dermis were best preserved with the NaCl/Triton X‐100. The impact on the 3D structure and vascular holes was detrimental with Dispase II/SDS. Elastic fibre fragmentation was only observed after Dispase II incubation. HD‐OCT showed that NaCl/Triton X‐100 processed matrices permitted in vitro repopulation by human dermal fibroblasts (confirmed by MTT test and histology) and underwent remodelling upon increasing incubation time. Care must be taken in choosing the appropriate processing steps to maintain selected properties of the extracellular matrix in HADMs. Processing HADMs with NaCl/Triton X‐100 permits in vitro the proliferation and remodelling activity of human dermal fibroblasts. HD‐OCT provides unique real‐time and non‐invasive 3D imaging of tissue‐engineered skin constructs and complementary morphological and cytological information.     

Safety and Efficacy of Paclitaxel-Eluting Balloon Angioplasty for Dysfunctional Hemodialysis Access: A randomized trial Comparing with Angioplasty Alone

PurposeTo assess whether angioplasty of hemodialysis access (HA) stenosis with a drug-coated balloon (DCB) would prevent restenosis in comparison with plain-balloon percutaneous transluminal angioplasty (PTA).Materials and MethodsThis prospective randomized clinical trial enrolled 120 patients with dysfunctional arteriovenous fistulae (n = 109) and grafts (n = 11), due to a ≥50% stenosis between March 2014 and April 2018. All patients underwent high-pressure balloon angioplasty and were then randomized to either DCB (n = 60) or PTA (n = 60). Patients were followed-up for 1 year, and angiography was performed 6 months after angioplasty. The primary endpoint was the late lumen loss (LLL) at 6 months. Secondary endpoints included other angiographic parameters at 6 months and HA failures, adverse event, and mortality at 12 months. Continuous variables were compared with a Student t-test, and Kaplan-Meier curves were used for freedom from HA failure and for mortality.ResultsLLL in the DCB and in the PTA group were 0.64 mm ± 1.20 and 1.13 mm ± 1.51, respectively (P = .082, adjusted P = .0498). DCB was associated with lower percentage stenosis (54.2% ± 19.3 vs 61.7% ± 18.2; P = .047) and binary restenosis ≥50% (56.5% vs 81.1%; P = .009) than PTA. The number of HA failures after 12 months was lower for DCB than for PTA (45% vs 66.7%; P = .017). Mortality at 12 months was 10% and 8.3% in the DCB and PTA groups, respectively (P = .75).ConclusionsDespite LLL improvement that failed to reach statistical significance, this study demonstrated decreased incidence and severity of restenosis with DCB compared with PTA to treat dysfunctional HA.