Validation of a Saliva-Based Test for the Molecular Diagnosis of SARS-CoV-2 Infection

Background. Since the beginning of the pandemic, clinicians and researchers have been searching for alternative tests to improve the screening and diagnosis of the SARS-CoV-2 infection. Currently, the gold standard for virus identification is the nasopharyngeal (NP) swab. Saliva samples, however, offer clear, practical, and logistical advantages but due to a lack of collection, transport, and storage solutions, high-throughput saliva-based laboratory tests are difficult to scale up as a screening or diagnostic tool. With this study, we aimed to validate an intralaboratory molecular detection method for SARS-CoV-2 on saliva samples collected in a new storage saline solution, comparing the results to NP swabs to determine the difference in sensitivity between the two tests. Methods. In this study, 156 patients (cases) and 1005 asymptomatic subjects (controls) were enrolled and tested simultaneously for the detection of the SARS-CoV-2 viral genome by RT-PCR on both NP swab and saliva samples. Saliva samples were collected in a preservative and inhibiting saline solution (Biofarma Srl). Internal method validation was performed to standardize the entire workflow for saliva samples. Results. The identification of SARS-CoV-2 conducted on saliva samples showed a clinical sensitivity of 95.1% and specificity of 97.8% compared to NP swabs. The positive predictive value (PPV) was 81% while the negative predictive value (NPV) was 99.5%. Test concordance was 97.6% (Cohen’s Kappa = 0.86 ; 95% CI 0.81-0.91). The LoD of the test was 5 viral copies for both samples. Conclusions. RT-PCR assays conducted on a stored saliva sample achieved similar performance to those on NP swabs, and this may provide a very effective tool for population screening and diagnosis. Collection of saliva in a stabilizing solution makes the test more convenient and widely available; furthermore, the denaturing properties of the solution reduce the infective risks belonging to sample manipulation.

Effect of Frequent Vaginal Saline Lavage On Maternal Infection Prevention During Mechanical Labor Induction

Background: Induction of labor is performed in up to 25% of pregnancies. The major concern in mechanical labor induction is that it increases the chance of infection when a foreign device is introduced into the cervix. The aim of the study is to test the effectiveness of a vagina saline lavage procedure on infection prevention during labor induction by transcervical double balloon catheter.Methods: Enrolled pregnant women were randomly divided into two groups. The control group received standard aseptic vaginal cleansing with 5% betadine solution. In addition to the standard aseptic preparation, the study group received vaginal lavage with 0.9% saline solution before the device placement and once every 4 hours after the insertion. Results: There was no statistical difference in the demographic characteristics or the indications for induction between the two groups (P > 0.1). The final delivery modes and complication rates were not significantly different (P > 0.05) between the two groups, except for the maternal infection rate (P < 0.05). The rate of infection dropped from 10.6% to 2.9% when the frequent vaginal lavage procedure was performed. Conclusions: Excessive vaginal aseptic preparation by saline solution is easy to apply, safe and effective in reducing maternal infection during mechanical labor induction.

Virucidal Activity of Different Mouthwashes Using a Novel Biochemical Assay

Background: Saliva of patients with COVID-19 has a high SARS-CoV-2 viral load. The risk of spreading the virus is not insignificant, and procedures for reducing viral loads in the oral cavity have been proposed. Little research to date has been performed on the effect of mouthwashes on the SARS-CoV-2 virus, and some of their mechanisms of action remain unknown. Methods: SARS-CoV-2 positive nasopharyngeal swabs measured by RT-PCR were used for virucidal activity in a 1:1 ratio, with an incubation time of 1 min. The solutions used in this study were: iodopovidone (8 mg); * D-limonene, a terpene extracted from citrus peels (0.3%); † cetylpyridinium chloride (0.1%) (CPC); ‡ chlorhexidine gluconate (10%) (CHX); § a CPC (0.12%) and CHX (0.05%) containing formula; ** a formula containing essential oils; †† a CPC containing formula (0.07%); ‡‡ a D-limonene (0.2%) and CPC (0.05%) containing formula; §§ a solution containing sodium fluoride (0.05%) and CPC (0.075%); *** a solution containing CHX (0.12%) and; ††† a CHX (0.2%) containing formula. ‡‡‡ As a control reaction, saline solution or excipient solution (water, glycerin, citric acid, colorant, sodium citrate) was used. Conclusion: Within the limitations of this study, we can conclude that a mouthwash containing both D-limonene and CPC reduced the virucidal activity in about 6 logs (>99.999% reduction). Hence, establishing a clinical protocol for dentists is suggested, where all patients to be treated rinse pre-operatively with a mouthwash containing both D-limonene and CPC to reduce the likelihood of infection with SARS-CoV-2 for dentists. This is a relatively inexpensive way to reduce viral transmission of SARS-CoV-2 from infected individuals within the community. It is also a simple way to decrease infections from asymptomatic and pre-symptomatic patients.

Improving the method for determining the physiological and sanitary potential of Gherkin seeds

Gherkin seeds usually show irregular physiological quality. Seed production requires fast and reliable tests to evaluate seed quality. Germination test is considered a recognized analysis method; however, seed technology has pursuit the improvement of vigor tests aiming the evaluation of seed’s physiological potential. Thus, the objective of this work was to evaluate procedures to perform the test of accelerated aging and determine the physiological and sanitary potential of gherkin seeds. Four seed lots of cultivar Liso Calcuta were used in the study. To evaluate the initial physiological quality the water content was determined and germination and emergence tests, as well as indices of germination speed and emergence speed were used. The accelerated aging test was performed as traditionally and with saturated saline solution, with 48, 72 and 96 hours, at temperatures of 41oC and 45oC. After aging, the water content was determined, and seeds’ germination and sanity tests were performed. The experiment was set under a completely random design in factorial 4x3x2 (lots x aging periods x temperatures). The standard accelerated aging test and the test with saturated saline solution at 41oC for 96 hours were efficient to evaluate the vigor of gherkin seeds. Saturated saline solution provides uniform water absorption and deterioration in gherkin seeds, allowing to discriminate seed lots in different vigor levels. The salinity test after accelerated aging with saline solution reduces the incidence of some fungi.

Antioxidant effect of Arrabideae chica (crajiru) extract on oxidative stress in diabetic rats

Objective: This study aimed to investigate the effects of the antioxidant potential of Arrabideae chica (crajiru) extract on oxidative stress in diabetic rats. Methods: Adult Wistar rats (Rattus norvegicus), weighing 238±12g were divided into three groups of six rats each: CN normal untreated control; DIAB+NS diabetic rats treated with normal saline; and diabetic rats treated with crajiru extract, DIAB+CR. The CN and DIAB+NS groups (control groups) received normal saline solution (NS) orally (gavage); rats in the DIAB+CR group received crajiru extract (300 mg/kg) once a day by gavage for 6 weeks. Measurements of urea and creatinine in serum, and kidney tissue catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx) were performed. The variables were assessed using the Tukey test, significance p<0.05. Results: All animals survived the experiments. In the CN group, compared with the DIAB+NS group, there was significant difference between the levels of glycemia on the second day of dosing and on the 10th day (p<0.05). No difference was observed on glycemia comparing the 2th and 10th day on the rats of group C+NS (p>0.05). Diabetic animals from DIAB+CR group had a significant reduction in glycemia on 10th day of treatment, comparing the 2nd day (p<0.05). There was a significant reduction in glycemia in the DIAB+CR group, comparing with the DIAB+NS group (p<0.05). There was an increase in urea and creatinine levels in rats DIAB+SN when compared to controls, C+SN (p<0.001). Rats from the DIAB+CR group had a significant reduction in urea and creatinine, compared to the DIAB+NS group (p<0.001). There were no significant differences in urea and creatinine comparing the C+NS and DIAB+CR groups. The rats from the DIAB+NS group had significantly lower levels of CAT, GSH-px and SOD when compared to the normal control rats (p<0.001). In animals from the DIAB+SN group, the levels of these antioxidant enzymes were significantly reduced (p<0.001). The treatment of diabetics with crajiru extract caused a significant increase (p<0.001) in the levels of CAT, GSH-px and SOD, when compared to rats in the BIAB+SN group. Conclusion: The data of the present study confirms that the crajiru extract positively influenced the control of hyperglycemia in diabetic rats. More research is needed to provide a better understanding of the mechanisms of diabetes treatment using crajiru extract and its flavonoids.

A statistical evaluation of the oral vaccine S3pvac papaya against cysticercosis of taenia psiformis

The objective of this paper is to compare and evaluate statistically the behavior of two vaccines against cysticercus in a sample of female rabbits. The two vaccines under discussion are 1) S3Pvac-Papaya12 mg and 2) Wild Type (WT) or S3P Wild and also 3) Saline Solution. The challenge is to show that the developed vaccine, S3Pvac-Papaya, produces more antibodies and with better stability than the other vaccine and saline solution. With the aim of proving this conjecture, an analysis of variance (ANOVA) and multiple Fisher comparisons at 95% confidence were performed. The vaccine of interest, S3Pvac-Papaya, revealed in the box diagram at T2 that the development of antibodies was high and showed little dispersion, which implies that the vaccine S3Pvac Papaya is statistically efficient in the production of antibodies. Finally, the mathematical contribution centers on highlighting the low use of inferential statistical techniques, comparing means of generated antibodies by a set of vaccines in order to determine which one is more efficient and reliable. Tacitly, a methodology both statistical and procedural has been proposed along this work, to apply when contrasting other kinds of vaccines in both animals and humans for diverse conditions.