Background rate of low-level HCV RNA in anti-HCV confirmed-positive and minipool nucleic acid test-nonreactive blood donations

BACKGROUND

In 2019, the Food and Drug Administration revised the requirement for further testing of anti-HCV-reactive donations testing nucleic acid (NAT)-nonreactive via routine mini-pool (MP)-NAT. Individual donation (ID)-HCV NAT was required as a supplemental test prior to a second FDA-licensed anti-HCV assay; if ID-HCV-NAT is reactive, no further testing is required. This study investigated the rate of low-level RNA in anti-HCV-reactive donation samples prior to and following the implementation of supplemental ID-HCV NAT.

STUDY DESIGN/METHODS

A retrospective analysis was conducted on frozen plasma unit samples from 1161 anti-HCV confirmed-positive/HCV-NAT-nonreactive donations collected from December 2014 to January 2020. Samples were tested by multiple replicates on the Grifols Procleix Ultrio Elite (UE) assay and corresponding discriminatory HCV (dHCV) assay on the Procleix Panther System. Prospectively, the prevalence of low-level RNA in 2912 anti-HCV-reactive donations detected through routine screening from April 2020 through March 2021 was determined.

RESULTS

In retrospective analyses, 10 (0.86%) of 1161 plasma samples were UE reactive, of which four (0.34%) were dHCV reactive (in all replicates of UE and dHCV). Of 2912 anti-HCV-reactive donation samples testing NAT-nonreactive via routine MP-NAT, three (0.1%; 95% CI: 0.04-0.30) were dHCV reactive; 37% of the remaining samples were reactive by a second anti-HCV assay and thus serologically confirmed.

CONCLUSIONS

Retrospective and prospective analysis in comparison to earlier studies revealed that low-level HCV-RNA reactivity is decreasing over time. The very low HCV-RNA rates may be due to the widespread use of highly effective, direct-acting anti-viral treatments for those diagnosed with HCV infection.

Impact of low-level BK polyomavirus viremia on intermediate-term renal allograft function

BACKGROUND

BK polyomavirus (BKPyV)-associated nephropathy (PyVAN) is a significant cause of premature renal transplant failure. High-level BKPyV viremia is predictive for PyVAN; however, low-level BKPyV viremia does not necessarily exclude the presence of PyVAN. As data are limited regarding whether or not low-level BKPyV viremia has an effect on intermediate-term graft outcome, this study analyzes the impact of low-level BKPyV viremia on intermediate-term graft function and outcome compared with high-level viremia and non-viremic patients.

METHODS

All renal transplant patients received follow-up examinations at the Department of Nephrology, University Hospital Essen. Patients were screened for BKPyV viremia and stratified into three groups according to their maximum BKPyV load in serum (low-level viremia, high-level viremia, and no viremia).

RESULTS

In 142 of 213 (67%) patients, BKPyV was never detected in serum; 42 of 213 (20%) patients were found positive for low-level viremia (≤10⁴ copies/mL); and 29 of 213 (13%) patients showed high-level viremia (>10⁴ copies/mL). No significant differences regarding transplant function and graft failure were observed between patients without BKPyV viremia (delta estimated glomerular filtration rate [eGFR] +0.1 mL/min [month 1 vs last visit at month 44]) and patients with low-level BKPyV viremia (delta eGFR -1.7 mL/min). In patients with high-level viremia, transplant function was significantly restricted (delta eGFR -6.5 mL/min) compared with low-level viremia until the last visit at 44 ± 9.7 months after transplantation. Although the graft function and graft loss were worse in the high-level viremia group compared with no viremia (eGFR 37 vs 45 mL/min), the difference was not significant.

CONCLUSIONS

High-level viremia was associated with impaired graft function. In contrast, low-level BKPyV viremia had no significant impact on intermediate-term graft function.

Comparative study among three different phototherapy protocols to treat chemotherapy-induced oral mucositis in hamsters

In this study, clinical, biochemical and histological analysis were used to compare different phototherapies, including LED, low and high-power laser (HPL) for the treatment of chemotherapy (CT)-induced oral mucositis (OM). One-hundred-fifty hamsters were divided into five groups: C: control; CH: CT/OM induction; L: CT/OM induction and treatment with LED (635 nm, 1.2 J), HL: CT/OM induction and treatment with HPL (808 nm, 10 J), LL: CT/OM induction and treatment with low-level laser therapy (LLLT) (660 nm, 1.2 J). OM was induced by scratches performed on check pouch mucosa after two injections of 5-Fluorouracil. The experiment lasted 10 days and OM was analyzed by specific clinical scales on days 5, 7 and 10. The animals were euthanized and the cheek pouch mucosa removed for biochemical (TNF-α concentration) and histological (light microscopy) analysis. After statistical analysis, the authors' results showed LED and LLLT therapies were efficient treatments for OM, decreasing TNF-α concentration on day 7 (p < 0.05) and completely healing the mucosa on day 10. HPL showed no interference in final healing of OM. According to the methodology used and the results obtained in the present study, LLLT and LED therapies were the best choices to decrease the severity of OM, accelerating tissue repair and decreasing the inflammatory process. Clinical evaluation of OM in Groups CH, LL, L and HL and their respective arrangement of phototherapy treatments at different time intervals (5, 7 and 10 days).

Placental arsenic concentrations in relation to both maternal and infant biomarkers of exposure in a US cohort

Arsenic crosses the placenta and may have adverse consequences in utero and later in life. At present, little is known about arsenic concentrations in placenta and their relation to maternal and infant exposures particularly at common levels of exposure. We measured placenta arsenic in a US cohort potentially exposed via drinking water from private wells, and evaluated the relationships between placenta and maternal and infant biomarker arsenic concentrations. We measured total arsenic concentrations in placental samples from women enrolled in the New Hampshire Birth Cohort Study (N=766). We compared these data to maternal urinary arsenic (total arsenic and individual species) collected at approximately 24-28 week gestation, along with maternal post-partum toenails and infant toenails using non-parametric multivariate analysis of log10-transformed data. We also examined the association between placental arsenic and household drinking water arsenic. Placenta arsenic concentrations were related to arsenic concentrations in maternal urine (β 0.55, P value <0.0001), maternal (β 0.30, P value 0.0196) and infant toenails (β 0.40, P value 0.0293) and household drinking water (β 0.09, P value <0.0001). Thus, our data suggest that placenta arsenic concentrations reflect both maternal and infant exposures.

Visual integration in autism

Atypical integration is a topic of debate in the autism literature. Some theories suggest that altered perception in autism spectrum disorder (ASD) is due to a failure to integrate information from meaningful context into the final percept, whereas others suggest that integration of low-level features is impaired. Empirical research which forms the basis for these theories has failed to account for higher-level influences not inherent in the stimuli (i.e., instructions and goals) and assess integration at both lower and higher perceptual levels within the same task. Here, we describe how perceived expectations and goals of a task can modulate the processing of low-level visual input via the medial prefrontal cortex (mPFC). We then go on to illustrate how future research might assess the relative contribution of both low and high-level processes using the same paradigm. We conclude by recommending that when results appear conflicting, consideration of the relative strength of low-level input vs. feedback or high-level processes may prove helpful. Importantly, research in this area needs to more broadly consider the various influences on perception, and find better ways to assess the contributions of early and later visual processes.

Light-emitting diode irradiation promotes donor site wound healing of the free gingival graft

BACKGROUND

This study aims to evaluate the effect of light-emitting diode (LED) light irradiation on the donor wound site of the free gingival graft.

METHODS

Rat gingival fibroblasts were chosen to assess the cellular activities and in vitro wound healing with 0 to 20 J/cm(2) LED light irradiation. Seventy-two Sprague-Dawley rats received daily 0, 10 (low-dose [LD]), or 20 (high-dose [HD]) J/cm(2) LED light irradiation on the opened palatal wound and were euthanized after 4 to 28 days; the healing pattern was assessed by histology, histochemistry for collagen deposition, and immunohistochemistry for tumor necrosis factor (TNF)-α infiltration. The wound mRNA levels of heme oxygenase-1 (HO-1), TNF-α, the receptor for advanced glycation end products, vascular endothelial growth factor, periostin, Type I collagen, and fibronectin were also evaluated.

RESULTS

Cellular viability and wound closure were significantly promoted, and cytotoxicity was inhibited significantly using 5 J/cm(2) LED light irradiation in vitro. The wound closure, reepithelialization, and collagen deposition were accelerated, and sequestrum formation and inflammatory cell and TNF-α infiltration were significantly reduced in the LD group. HO-1 and TNF-α were significantly upregulated in the HD group, and most of the repair-associated genes were significantly upregulated in both the LD and HD groups at day 7. Persistent RAGE upregulation was noted in both the LD and HD groups until day 14.

CONCLUSION

LED light irradiation at 660 nm accelerated palatal wound healing, potentially via reducing reactive oxygen species production, facilitating angiogenesis, and promoting provisional matrix and wound reorganization.

Tooth movement alterations by different low level laser protocols: a literature review

Low-Level Laser Therapy (LLLT) provides several benefits for patients receiving orthodontic treatment. According to some literatures, Orthodontic Tooth Movement (OTM) can be enhanced but some investigators have reported contradictory results. This article reviews the literature regarding the different aspects of the use of LLLT on OTM and its alterations. The general data regarding the study design, sample size, wavelength (nm), power (mW), and duration were extracted and recorded independently. Electronic databases of PubMed and ScienceDirect from January 2009 to August 2014 were searched. Also Google Scholar and grey literature was searched for relevant references. Some investigators found that the amount of tooth movement in the Low-Energy Laser Irradiation (LELI) group was significantly greater than in the nonirradiation group by the end of the experimental period. Low-level laser irradiation accelerates the bone remodeling process by stimulating osteoblastic and osteoclastic cell proliferation and function during orthodontic tooth movement. But some researchers have reported that no statistical differences in the mean rate of tooth movement were noted between low energy and high energy experimental sides and their controls. Some evidence shows that low-level laser irradiation accelerates the bone remodeling process and some evidence shows that LLLT has not effect on OTM. In some investigations no statistical differences in the mean rate of tooth movement can be seen between low energy and high energy experimental sides and their controls. It has been shown by authors that laser irradiation can reduce the amount of OTM and a clinical usage for the inhibitory role of low level laser irradiation is enforcing the anchorage unit.

Low-level laser therapy improves peri-implant bone formation: resonance frequency, electron microscopy, and stereology findings in a rabbit model

Previous studies have reported positive effects of low-level laser therapy (LLLT) on bone healing. This study evaluated the effects of LLLT on peri-implant healing in vivo. Thirty-two rabbits had their mandibular left incisors removed, followed by immediate insertion of a dental implant into the fresh socket. Animals were assigned randomly to four groups: control (non-irradiated) or LLLT at three different doses per session: 5J/cm(2), 10J/cm(2), and 20J/cm(2). A GaAlAs laser (830nm, 50mW) was applied every 48h for 13 days, starting immediately after surgery. The implant stability quotient (ISQ) was measured using resonance frequency analysis upon implant insertion and immediately after death, 30 days after the last application. Tissues were prepared for scanning electron microscopy (SEM) and stereology. Variables measured were bone-implant contact (BIC) and bone neoformation within implant threads at three different sites. The results showed better ISQ for the 20J/cm(2) group (P=0.003). BIC values were significantly higher (P<0.05) in the 20J/cm(2) group, on both SEM and stereology. Bone area values were better in the 10J/cm(2) (P=0.036) and 20J/cm(2) (P=0.016) groups compared to the control group. Under these conditions, LLLT enhanced peri-implant bone repair, improving stability, BIC, and bone neoformation. The findings support and suggest parameters for the design of clinical trials using LLLT after implant placement.

Low level laser effect in treatment of patients with intractable tinnitus due to sensorineural hearing loss

INTRODUCTION

Tinnitus is defined as a perception of sound without an external acoustic stimulus. Due to large number of causes and limited knowledge of its pathophysiology, tinnitus still remains an obscure symptom.

METHODS

This was a cross-sectional study on 120 patients with tinnitus and sensorineural hearing loss who were randomly divided into two groups; one group received low-level laser and the second group used the same instrument but off, for 20 sessions of 20 minutes. A tinnitus handicap inventory (THI) and Visual Analog Scale (VAS) were used to evaluate the severity of patients' symptoms. Severity and frequency of tinnitus were also determined using Audiometric tests.

RESULTS

The average age of the 120 patients in the two groups of study were not statistically significantly different. The mean difference of severity of tinnitus between the two groups was statistically significant at the end of the study and 3 month after completion of treatment. The VAS and THI mean differences after the treatment were statistically significant between the two groups but not statistically significant after 3 months of completion the study.

CONCLUSION

Low level laser radiation is effective for short-term treatment of Tinnitus caused by sensorineural hearing loss and its impact may be reduced over the time.

Low-level laser therapy can produce increased aggressiveness of dysplastic and oral cancer cell lines by modulation of Akt/mTOR signaling pathway

Low-level laser therapy (LLLT) is a non-thermal phototherapy used in several medical applications, including wound healing, reduction of pain and amelioration of oral mucositis. Nevertheless, the effects of LLLT upon cancer or dysplastic cells have been so far poorly studied. Head and neck cancer patients receiving LLLT for oral mucositis, for example, might have remaining tumor cells that could be stimulated by LLLT. This study demonstrated that LLLT (GaAlAs--660 nm or 780 nm, 40 mW, 2.05, 3.07 or 6.15 J/cm²) can modify oral dysplastic cells (DOK) and oral cancer cells (SCC9 and SCC25) growth by modulating the Akt/mTOR/CyclinD1 signaling pathway; LLLT significantly modified the expression of proteins related to progression and invasion in all the cell lines, and could aggravate oral cancer cellular behavior, increasing the expression of pAkt, pS6 and Cyclin D1 proteins and producing an aggressive Hsp90 isoform. Apoptosis was detected for SCC25 and was related to pAkt levels.

Platelet-rich plasma, low-level laser therapy, or their combination promotes periodontal regeneration in fenestration defects: a preliminary in vivo study

BACKGROUND

This study histomorphometrically analyzes the influence of platelet-rich plasma (PRP), low-level laser therapy (LLLT), or their combination on the healing of periodontal fenestration defects (PFDs) in rats.

METHODS

PFDs were surgically created in the mandibles of 80 rats. The animals were randomly divided into four groups: 1) C (control) and 2) PRP, defects were filled with blood clot or PRP, respectively; 3) LLLT and 4) PRP/LLLT, defects received laser irradiation, were filled with blood clot or PRP, respectively, and then irradiated again. Animals were euthanized at either 10 or 30 days post-surgery. Percentage of new bone (NB), density of newly formed bone (DNB), new cementum (NC), and extension of remaining defect (ERD) were histomorphometrically evaluated. Data were statistically analyzed (analysis of variance; Tukey test, P <0.05).

RESULTS

At 10 days, group PRP presented ERD significantly lower than group C. At 30 days, group PRP presented NB and DNB significantly greater than group C. Groups LLLT, PRP, and PRP/LLLT showed significant NC formation at 30 days, with collagen fibers inserted obliquely or perpendicularly to the root surface. NC formation was not observed in any group C specimen.

CONCLUSIONS

LLLT, PRP, or their combination all promoted NC formation with a functional periodontal ligament. The combination PRP/LLLT did not show additional positive effects compared to the use of either therapy alone.