Category: Nevin Manimala

Int J Biostat. 2021 Sep 30. doi: 10.1515/ijb-2020-0043. Online ahead of print.

ABSTRACT

We present in this paper a global methodology for the spike detection in a biological context of fluorescence recording of GnRH-neurons calcium activity. For this purpose we first propose a simple stochastic model that could mimic experimental time series by considering an autoregressive AR(1) process with a linear trend and specific innovations involving spiking times. Estimators of parameters with asymptotic normality are established and used to set up a statistical test on estimated innovations in order to detect spikes. We compare several procedures and illustrate on biological data the performance of our procedure.

PMID:34598374 | DOI:10.1515/ijb-2020-0043

Radiol Oncol. 2021 Sep 27. doi: 10.2478/raon-2021-0037. Online ahead of print.

ABSTRACT

BACKGROUND: All the patients with suspected stroke are directed to whole-brain CT scan. The purpose of this scan is to look for early features of ischemia and to rule out alternative diagnoses than stroke. In case of ischemic stroke, CT diagnostics (including CT angiography) is used mainly to locate the occlusion and its size, while the Hounsfield Units (HU) values of the thrombus causing the stroke are usually overlooked on CT scan or considered not important. The aim of this study was to demonstrate that the HU value is relevant and can help in better treatment planning.

PATIENTS AND METHODS: There were 25 patients included in the study, diagnosed with ischemic stroke in the middle cerebral artery (MCA) territory. In all patients, systemic thrombolysis was not successful and the mechanical recanalization was needed. The retrieved thrombi were also analyzed histologically for the determination of red blood cells (RBC) proportion. CT of the proximal MCA (M1) segment was analyzed for average HU value and its variability both in the occluded section and the symmetrical normal site. These CT parameters were then statistically studied for the possible correlations with different clinical, histological and procedure parameters using the Linear Regression and the Pearson correlation coefficient.

RESULTS: Relevant positive correlations were found between average HU value of thrombus and outcome modified Rankin Scale (mRS), initial mRS, number of passes with thrombectomy device as well as RBC proportion.

CONCLUSIONS: Results of the present study suggest that measured HU values in CT images of the cerebral thrombi may help in the assessment of thrombus compaction and therefore better treatment planning.

PMID:34598375 | DOI:10.2478/raon-2021-0037

Eur J Dent. 2021 Oct 1. doi: 10.1055/s-0041-1731926. Online ahead of print.

ABSTRACT

OBJECTIVE: Currently, dental implants are a predictable treatment option for oral rehabilitation; however, complications such as peri-implant diseases are increasing every day. Thus, the aim of this study was to verify the efficacy, in vitro, of two protocols against cultures of periodontal biofilm and Staphylococcus aureus.

MATERIAL AND METHODS: Petri dishes for each of the following groups were used: control groups (C)-plates inoculated with periodontal biofilm (C.B; n = 4) or S. aureus (C.SA; n = 4) without any treatment; laser groups-plates inoculated with periodontal biofilm (low-level laser therapy [LLLT].B; n = 4) or S. aureus (LLLT.SA; n = 4) and treated with LLLT (660 nm, 30 mW, 50 J/cm², and 47 seconds); antimicrobial photodynamic therapy groups (aPDT)-plates inoculated with periodontal biofilm (aPDT.B; n = 4) or S. aureus (aPDT.SA; n = 4) and treated with aPDT (red laser 660 nm, 30 mW, 50 J/cm², 47 seconds + toluidine blue O (TBO) 100 µg/mL, and 1 minute). After treatments were performed, the contents of all plates were diluted and seeded for counting colony-forming units (CFUs).

STATISTICAL ANALYSIS: Results were analyzed with one-way analysis of variance (ANOVA), Tukey’s test, comparison of percentages, and independent t-tests with a 5% significance level.

RESULTS: Both treatments, LLLT and aPDT, significantly reduced the number of CFUs for the two types of culture, LLLT.B (3.69 × 10⁶ ± 0.20), aPDT.B (2.79 × 10⁶ ± 0.13), LLLT.SA (4.10 × 10⁶ ± 0.12), and aPDT.SA (3.23 × 10⁶ ± 0.10) when compared with control groups C.B (5.18 × 10⁶ ± 0.43) and C.SA (5.81 × 10⁶ ± 0.16; p = 0.000). When treatment groups were compared separately, there was also a statistically significant difference (p = 0.000). None of the protocols were able to eliminate cultured microorganisms.

CONCLUSION: The LLLT and aPDT protocols effectively reduced cultures of periodontal biofilm and S. aureus in vitro, with the superiority of aPDT.

PMID:34598294 | DOI:10.1055/s-0041-1731926

Eur J Dent. 2021 Oct 1. doi: 10.1055/s-0041-1731928. Online ahead of print.

ABSTRACT

OBJECTIVES: This study was aimed to assess (1) the prevalence of salivary and gastric Helicobacter pylori (HP) infection in patients with and without periodontitis, (2) the prevalence of HP infection in patients with periodontitis according to its clinical classification, (3) the effect of periodontitis treatment in patients with or without gastric HP infection, and (4) if gastric HP eradication in combination with periodontitis treatment influences periodontitis clinical outcome.

MATERIALS AND METHODS: Thirty-three adults with periodontitis treated by quadrant scaling and root planning (QSRP). The simplified plaque index (PI), bleeding on probing index (BOP), probing pocket depth (PPD), and clinical attachment level (CAL) were assessed pretreatment and 3 months of posttreatment. The patients were tested for oral and gastric HP. Gastric HP (+) patients received eradication therapy. A control group of 32 periodontically healthy volunteers was tested for oral and gastric HP. Saliva samples were evaluated by real-time polymerase chain reaction (rtPCR); gastric HP was detected by urea breath test (UBT).

STATISTICAL ANALYSIS: Normality of variables assessed by the Kolmogorov-Smirnov test, while the differences of pre- and post-treatment were analyzed by paired samples t-test. Differences between subgroups were compared by a Student’s t-test or a Mann-Whitney U-test. Comparisons of nominal variables were made by Pearson’s Chi-square test.

RESULTS: No saliva samples were positive for HP. Gastric HP was detected in six patients with periodontitis and seven controls (p > 0.05). HP infection affected patients with higher disease stages and grades. All HP (+) patients underwent successful eradication treatment. All clinical periodontitis indices improved following QSRP. HP (+) patients who received QSRP as adjunctive to eradication treatment showed improvement in BOP (p < 0.001), PI (p < 0.013), and CAL (p < 0.004) compared with HP (-) patients who received QSRP alone.

CONCLUSION: Periodontitis was not associated with gastric HP infection. Saliva was not a gastric HP supply reservoir. Gastric HP infection was associated with advanced stages and degrees of periodontitis. Although all periodontal clinical markers improved after QSRP, BOP, PI, and CAL, they were further improved when combined with eradication treatment. Periodontal evaluation and treatment combined with HP eradication are recommended in patients with HP gastric infection.

PMID:34598295 | DOI:10.1055/s-0041-1731928

J Reconstr Microsurg. 2021 Oct 1. doi: 10.1055/s-0041-1735834. Online ahead of print.

ABSTRACT

INTRODUCTION: Vasospasm is a major problem following microsurgical reconstruction which can result in the partial or complete loss of the flap tissue. The aim of this study was to investigate the efficiency of hydrodilatation for the prevention of vasospasm.

MATERIAL AND METHODS: Thirty male Wistar rats were used for this experimental study. Femoral arteries of were exposed, photographed, and transected. In group 1, group 2, and group 3 papaverine solution, hydrodilatation, and minimal mechanical dilatation (control group) was performed, respectively. The anastomosis was completed and the arteries were photographed again 10 minutes after completion of the anastomosis. Following 7-day period samples for transmission electron microscopy (TEM) and light microscopy were obtained.

RESULTS: The mean vessel diameters prior to transection were 0.43, 0.45, and 0.52 mm in the papaverine, hydrodilatation, and control groups, respectively. The mean vessel diameter 10 minutes following the completion of anastomosis was 0.76, 0.75, and 0.51 mm in the papaverine, hydrodilatation, and control groups, respectively. Median score for papaverine group regarding histological parameters of regular endothelial lining and lumen, neutrophil infiltration, vascular congestion, and edema in tunica adventitia was 2, 3, 2, and 3 positive, respectively. Median score for the papaverine group regarding histological parameters of regular endothelial lining and lumen, neutrophil infiltration, vascular congestion, and edema in tunica adventitia was 3, 3, 3, and 3 positive, respectively. All the histological scores were negative in the control group. The difference between the control group and the experiment groups 1 and 2 was significant regarding all four histological parameters (p < 0.05).

CONCLUSION: Hydrodilatation and papaverine application were both effective in preventing vasospasm following microsurgical intervention but papaverine caused slightly less damage to the endothelial lining and less edema in the tunica adventitia when compared with the hydrodilatation. Hydrodilatation group showed a vasodilatory effect that was statistically similar to that of papaverine, which has a proven efficacy.

PMID:34598279 | DOI:10.1055/s-0041-1735834

Eur J Dent. 2021 Oct 1. doi: 10.1055/s-0041-1734469. Online ahead of print.

ABSTRACT

OBJECTIVE: The study aimed to compare the resin-dentin interface of sound and eroded dentin using universal and total-etch adhesive systems.

MATERIAL AND METHODS: Forty caries-free extracted human premolars were collected, and the occlusal surfaces were ground by using slow speed diamond disc with copious water supply until a flat superficial dentin was exposed. The test group underwent erosive cycle (n = 20), and another group (n = 20) was reserved for control group. Erosive protocol consisted of immersion in 1.23% citric acid for 1 minute every 12 hours and stored in artificial saliva. Both the control and eroded teeth were further subdivided (n = 10) for composite restoration by using either self-etch or total-etch systems. Then the tooth samples were sectioned longitudinally and observed under confocal laser scanning microscope at ×10 magnification to evaluate resin tag length and hybrid layer thickness.

STATISTICAL ANALYSIS: The data obtained were analyzed by using independent t-test.

RESULTS: The highest mean value of the resin tag length and thickness of hybrid layer was observed with total-etch system in sound dentin group compared with other groups (p < 0.001).

CONCLUSION: The resin-dentin interface of sound dentin was found to be better than eroded dentin by using total-etch system. The resin-dentin interface of eroded dentin was superior to sound dentin by using self-etch adhesive system.

PMID:34598293 | DOI:10.1055/s-0041-1734469

J Neurosurg Spine. 2021 Oct 1:1-10. doi: 10.3171/2021.5.SPINE202105. Online ahead of print.

ABSTRACT

OBJECTIVE: This study assesses how degree of overlap, either before or after the critical operative portion, affects lumbar fusion outcomes.

METHODS: The authors retrospectively studied 3799 consecutive patients undergoing single-level, posterior-only lumbar fusion over 6 years (2013-2019) at a university health system. Outcomes recorded within 30-90 and 0-90 postoperative days included emergency department (ED) visit, readmission, reoperation, overall morbidity, and mortality. Furthermore, morbidity and mortality were recorded for the duration of follow-up. The amount of overlap that occurred before or after the critical portion of surgery was calculated as a percentage of total beginning or end operative time. Subsequent to initial whole-population analysis, coarsened exact-matched cohorts of patients were created with the least and most amounts of either beginning or end overlap. Univariate analysis was performed on both beginning and end overlap exact-matched cohorts, with significance set at p < 0.05.

RESULTS: Equivalent outcomes were observed when comparing exact-matched patients. Among the whole population, the degree of beginning overlap was correlated with reduced ED visits within 30-90 and 0-90 days (p = 0.007, p = 0.009; respectively), and less 0-90 day morbidity (p = 0.037). Degree of end overlap was correlated with fewer 30-90 day ED visits (p = 0.015). When comparing only patients with overlap, degree of beginning overlap was correlated with fewer 0-90 day reoperations (p = 0.022), and no outcomes were correlated with degree of end overlap.

CONCLUSIONS: The degree of overlap before or after the critical step of surgery does not lead to worse outcomes after lumbar fusion.

PMID:34598156 | DOI:10.3171/2021.5.SPINE202105

Opt Lett. 2021 Oct 1;46(19):5059-5062. doi: 10.1364/OL.436334.

ABSTRACT

Laser speckle contrast imaging (LSCI) can be used to evaluate blood flow based on spatial or temporal speckle statistics, but its accuracy is undermined by out-of-focus image blur. In this Letter, we show how the fraction of dynamic versus static light scattering is dependent on focus, and describe a deconvolution strategy to correct for out-of-focus blur. With the aid of a z-splitter, which enables instantaneous multifocus imaging, we demonstrate depth-resolved LSCI that can robustly extract multi-plane structural and flow-speed information simultaneously. This method is applied to in vivo imaging of blood vessels in a mouse cortex and provides improved estimates of blood flow speed throughout a depth range of 300µm.

PMID:34598268 | DOI:10.1364/OL.436334

J Neurosurg. 2021 Oct 1:1-13. doi: 10.3171/2021.4.JNS203891. Online ahead of print.

ABSTRACT

OBJECTIVE: Patients with skull base meningioma (SBM) often require complex surgery around critical neurovascular structures, placing them at high risk of poor health-related quality of life (HRQOL) and possibly neurocognitive dysfunction. As the survival of meningioma patients is near normal, long-term neurocognitive and HRQOL outcomes are important to evaluate, including evaluation of the impact of specific tumor location and treatment modalities on these outcomes.

METHODS: In this multicenter cross-sectional study including patients 5 years or more after their last tumor intervention, Short-Form Health Survey (SF-36) and European Organisation for Research and Treatment of Cancer (EORTC) QLQ-BN20 questionnaires were used to assess generic and disease-specific HRQOL. Neurocognitive functioning was assessed with standardized neuropsychological assessment. SBM patient assessments were compared with those of 1) informal caregivers of SBM patients who served as controls and 2) convexity meningioma patients. In addition, the authors compared anterior/middle SBM patients with posterior SBM patients and anterior/middle and posterior SBM patients separately with controls. Multivariable and propensity score regression analyses were performed to correct for possible confounders.

RESULTS: Patients with SBM (n = 89) with a median follow-up of 9 years after the last intervention did not significantly differ from controls (n = 65) or convexity meningioma patients (n = 84) on generic HRQOL assessment. Statistically significantly but not clinically relevantly better disease-specific HRQOL was found for SBM patients compared with convexity meningioma patients. Anterior/middle SBM patients (n = 62) had significantly and clinically relevantly better HRQOL in SF-36 and EORTC QLQ-BN20 scores than posterior SBM patients (n = 27): physical role functioning (corrected difference 17.1, 95% CI 0.2-34.0), motor dysfunction (-10.1, 95% CI -17.5 to -2.7), communication deficit (-14.2, 95% CI -22.7 to -5.6), and weakness in both legs (-10.1, 95% CI -18.8 to -1.5). SBM patients whose primary treatment was radiotherapy had lower HRQOL scores compared with SBM patients who underwent surgery on two domains: bodily pain (-33.0, 95% CI -55.2 to -10.9) and vitality (-18.9. 95% CI -33.7 to -4.1). Tumor location and treatment modality did not result in significant differences in neurocognitive functioning, although 44% of SBM patients had deficits in at least one domain.

CONCLUSIONS: In the long term, SBM patients do not experience significantly more sequelae in HRQOL and neurocognitive functioning than do controls or patients with convexity meningioma. Patients with posterior SBM had poorer HRQOL than anterior/middle SBM patients, and primary treatment with radiotherapy was associated with worse HRQOL. Neurocognitive functioning was not affected by tumor location or treatment modality.

PMID:34598137 | DOI:10.3171/2021.4.JNS203891

Neurosurg Focus. 2021 Oct;51(4):E9. doi: 10.3171/2021.7.FOCUS21333.

ABSTRACT

OBJECTIVE: Cervical fractures in patients with ankylosing spondylitis can have devastating neurological consequences. Currently, several surgical approaches are commonly used to treat these fractures: anterior, posterior, and anterior-posterior. The relative rarity of these fractures has limited the ability of surgeons to objectively determine the merits of each. The authors present an updated systematic review and meta-analysis investigating the utility of anterior surgical approaches relative to posterior and anterior-posterior approaches.

METHODS: After a comprehensive literature search of the PubMed, Cochrane, and Embase databases, 7 clinical studies were included in the final qualitative and 6 in the final quantitative analyses. Of these studies, 6 compared anterior approaches with anterior-posterior and posterior approaches, while 1 investigated only an anterior approach. Odds ratios and 95% confidence intervals were calculated where appropriate.

RESULTS: A meta-analysis of postoperative neurological improvement revealed no statistically significant differences in gross rates of neurological improvement between anterior and posterior approaches (OR 0.40, 95% CI 0.10-1.59; p = 0.19). However, when analyzing the mean change in neurological function, patients who underwent anterior approaches had a significantly lower mean change in postoperative neurological function relative to patients who underwent posterior approaches (mean difference [MD] -0.60, 95% CI -0.76 to -0.45; p < 0.00001). An identical trend was seen between anterior and anterior-posterior approaches; there were no statistically significant differences in gross rates of neurological improvement (OR 3.05, 95% CI 0.84-11.15; p = 0.09). However, patients who underwent anterior approaches experienced a lower mean change in neurological function relative to anterior-posterior approaches (MD -0.46, 95% CI -0.60 to -0.32; p < 0.00001). There were no significant differences in complication rates between anterior approaches, posterior approaches, or anterior-posterior approaches, although complication rates trended lower in patients who underwent anterior approaches.

CONCLUSIONS: The results of this review and meta-analysis demonstrated the varying benefits of anterior approaches relative to posterior and anterior-posterior approaches in treatment of cervical fractures associated with ankylosing spondylitis. While reports demonstrated lower degrees of neurological improvement in anterior approaches, they may benefit patients with less-severe injuries if lower complication rates are desired.

PMID:34598150 | DOI:10.3171/2021.7.FOCUS21333