Effects of <Emphasis Type="SmallCaps">l</Emphasis>-Canavanine and ozone on vascular reactivity in septicemic rats

Septicemia leads to oxidative stress with overproduction of reactive-oxygen species (ROS) and consumption of endogenous antioxidant enzymes. We tested a twofold hypothesis: (1) does oxidative stress (OxS) induced by sepsis acting alone or in concert with augmented inflammatory processes contributes to sepsis-related vascular dysfunction, and, (2) whether ozone (O₃) and l-canavanine (CAV) mitigate the negative impact of the aforementioned phenomena. We investigated the relative impact of treatment with CAV and/or O₃ on vascular OxS associated vascular functional changes in septicemic rats. For this study, 60 male Sprague–Dawley rats were used and divided into six experimental groups (n = 10): control group (C), sham-operated (Sham), septicemic rats (S), S rats treated with CAV (100 mg/kg. i.p; S + CAV), S rats treated with O₃ (1.2 mg/kg, i.p.; S + O₃) and S rats treated with both O₃ and CAV (S + O₃ + CAV). After 22 h, the mean arterial blood pressure (MAP), the aortic ring vascular reactivity to phenylephrine, abdominal aortic blood flow (AABF), serum tumor necrosis factor-α (TNF-α) and plasma nitrite/nitrate (NOx) concentration were measured. In addition, hepatic antioxidant enzyme activities sodium dismutase (SOD) and glutathione peroxidase (GSH-Px) were estimated. Septicemia caused significant elevation of serum TNF-α (p < 0.001) and plasma NOx (p < 0.001) and significant (p < 0.001) reduction of AABF (p < 0.001), aortic vascular response to phenylephrine (p < 0.001), MAP (p < 0.001) and hepatic SOD and GSH-Px activity (p < 0.001) compared with the C group, while treatment with O₃ and/or CAV induced significant amelioration of all those increases. Abnormalities were attenuated to a similar extent with treatment with both O₃ and CAV. These results suggested that concomitant administration of O₃ and CAV alleviated the compromised vascular reactivity in septicemic conditions and prevent its progression into septic shock compared with each alone.     

Rapid testing requires clinical evaluation for accurate diagnosis of dengue disease: A passive surveillance study in Southern Malaysia

BackgroundDengue fever is the most common mosquito-borne infection worldwide where an expanding surveillance and characterization of this infection are needed to better inform the healthcare system. In this surveillance-based study, we explored the prevalence and distinguishing features of dengue fever amongst febrile patients in a large community-based health facility in southern peninsular Malaysia.MethodsOver six months in 2018, we recruited 368 adults who met the WHO 2009 criteria for probable dengue infection. They underwent the following blood tests: full blood count, dengue virus (DENV) rapid diagnostic test (RDT), ELISA (dengue IgM and IgG), nested RT-PCR for dengue, multiplex qRT-PCR for Zika, Chikungunya and dengue as well as PCR tests for Leptopspira spp., Japanese encephalitis and West Nile virus.ResultsLaboratory-confirmed dengue infections (defined by positive tests in NS1, IgM, high-titre IgG or nested RT-PCR) were found in 167 (45.4%) patients. Of these 167 dengue patients, only 104 (62.3%) were positive on rapid diagnostic testing. Dengue infection was significantly associated with the following features: family or neighbours with dengue in the past week (AOR: 3.59, 95% CI:2.14–6.00, p<0.001), cutaneous rash (AOR: 3.58, 95% CI:1.77–7.23, p<0.001), increased temperature (AOR: 1.33, 95% CI:1.04–1.70, p = 0.021), leucopenia (white cell count < 4,000/μL) (AOR: 3.44, 95% CI:1.72–6.89, p<0.001) and thrombocytopenia (platelet count <150,000/μL)(AOR: 4.63, 95% CI:2.33–9.21, p<0.001). Dengue infection was negatively associated with runny nose (AOR: 0.47, 95% CI:0.29–0.78, p = 0.003) and arthralgia (AOR: 0.42, 95% CI:0.24–0.75, p = 0.004). Serotyping by nested RT-PCR revealed mostly mono-infections with DENV-2 (n = 64), DENV-1 (n = 32) and DENV-3 (n = 17); 14 co-infections occurred with DENV-1/DENV-2 (n = 13) and DENV-1/DENV-4 (n = 1). Besides dengue, none of the pathogens above were found in patients’ serum.ConclusionsAcute undifferentiated febrile infections are a diagnostic challenge for community-based clinicians. Rapid diagnostic tests are increasingly used to diagnose dengue infection but negative tests should be interpreted with caution as they fail to detect a considerable proportion of dengue infection. Certain clinical features and haematological parameters are important in the clinical diagnosis of dengue infection.     

Cluster mechanism for sensing data report using robust collaborative distributed spectrum sensing

Cluster Computing - In cooperative mobile communications, spectrum sensing performance may encounter difficulties, which alert with many reporting errors, especially in dense network scenarios. In...     

Improved synthesis and pharmacologic activity of the enantiomers of a new benzofurane type antiarrhythmic compound

An improved synthesis of the enantiomers of the new benzofurane-type antiarrhythmic compound 1 is described, which makes use of the enantiomerically pure mbe-lactol. Thus, acylation of the benzofurane 4 with acetic anhydride and subsequent bromination gave the bromoacetyl-derivative 6 , which, after reduction with LiAlH₄, was protected with mbe-lactol to give a mixture of the diastereomers 8A and 8b . After separation via column chromatography assignment of absolute configuration was carried out using a well-established NMR- method. Reaction with propylamine and cleavage of the protective group gave (R)- 1 and (S)- 1 , respectively. Enantiomeric purity was confirmed using a direct HPLC method with rsp-cyclodextrine as stationary phase. Pharmacological investigations on isolated guinea pig heart muscle preparations showed that GE 68 and its two enantiomers did not significantly differ from each other with regard to their negative inotropic, negative chronotropic, and lack of β-adrenoceptor blocking action. In contrast, the reference drug propafenone was equally potent in its negative inotropic and chronotropic activity as GE 68, but additionally showed a weak β-adrenoceptor blocking activity. © 1994 Wiley-Liss, Inc.     

SARS-CoV-2 spike L452R variant evades cellular immunity and increases infectivity

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