Tag: statistics

Int J Comput Assist Radiol Surg. 2021 Nov 2. doi: 10.1007/s11548-021-02522-x. Online ahead of print.

ABSTRACT

PURPOSE: The amount of ultrasound (US) breast examinations continues to grow rapidly because of the wider endorsement of breast cancer screening programs. Cysts are the most commonly diagnosed breast lesions. Atypical breast cysts can be a serious differentiation problem in the US. Our goal was to develop noninvasive automated US grayscale image analysis for the cystic and solid breast lesion differentiation based on mathematical image post-processing.

MATERIALS AND METHODS: We used a set of 217 ultrasound images of proven 107 cystic (including 53 atypical) and 110 solid lesions. Empirical statistical and morphological models of the lesions were used to obtain features. The AUC indicator and Student’s t test were used to assess the quality of the individual features. The Pearson correlation matrix was used to calculate the correlation between various features. The LASSO and stepwise regression methods were used to determine the most significant features. Finally, the lesion classification was carried out by the various methods.

RESULTS: The use of LASSO regression for the feature selection made it possible to select the most significant features for classification. The sensitivity increased from 87.1% to 89.2% and the specificity-from 92.2 to 94.8%. After the correlation matrix construction, it was found that features with a high value of the correlation coefficient (0.72; 0.75) can also be used to improve the quality of the classification.

CONCLUSION: The construction of the empirical model of the lesion pixels brightness behavior can provide parameters that are important for the correct classification of ultrasound images. The optimal set of features with the maximum discriminant characteristics may not be consistent with the correlation of features and the value of the AUC index. Features with a low AUC index (in our case 0.72) can also be important for improving the quality of the classification.

PMID:34727337 | DOI:10.1007/s11548-021-02522-x

Neurol Ther. 2021 Nov 2. doi: 10.1007/s40120-021-00296-7. Online ahead of print.

ABSTRACT

INTRODUCTION: C1q tumor necrosis factor (TNF)-related protein 9 (CTRP9) is a novel member of the C1q/TNF superfamily. According to our previous review, CTRP9 plays a vital role in the process of cardiovascular diseases, including regulating energy metabolism, modulating vasomotion, protecting endothelial cells, inhibiting platelet activation, inhibiting pathological vascular remodeling, stabilizing atherosclerotic plaques, and protecting the heart. We proposed that CTRP9 could play multiple positive and beneficial roles in vascular lesions in ischemic stroke (IS). Here, we aimed to study the relationship between serum CTRP9 and the etiology, severity, and prognosis of IS patients.

METHODS: A total of 302 patients with IS and 173 non-stroke controls were selected from the same hospital, and all patients with IS were followed up 12 months after stroke onset. Stroke etiology was classified according to the Trial of ORG 10172 in Acute Stroke Treatment classification. Symptomatic severity was determined using the National Institutes of Health Stroke Scale score. The lesion volume of acute cerebral ischemia was measured using magnetic resonance imaging (MRI). The unfavorable functional outcome was a combination of death or major disability 12 months after stroke onset. Receiver operating characteristic (ROC) curves and integrated discrimination improvement (IDI) and net reclassification improvement (NRI) statistics were applied in the statistical analysis.

RESULTS: We found that serum CTRP9 levels and the ratios of CTRP9/total cholesterol (TC), CTRP9/triglyceride (TG), CTRP9/low-density lipoprotein cholesterol (LDL-C), and CTRP9/high-density lipoprotein cholesterol (HDL-C) were associated with the presence of IS. Moreover, the serum CTRP9 concentration was positively associated with the severity of IS. Incorporation of CTRP9/LDL-C levels into a fully adjusted model for IS-cardioembolic (CE) improved discrimination and calibration, and significantly improved reclassification. In addition, CTRP9 was a predictor of unfavorable functional outcomes.

CONCLUSIONS: All the findings indicated that serum CTRP9 could be a promising blood-derived biomarker for the early evaluation and prognosis assessment of IS.

TRIAL REGISTRATION: Chinese Clinical Trial Registry, ChiCTR1800020330.

PMID:34727346 | DOI:10.1007/s40120-021-00296-7

Carbon Balance Manag. 2021 Nov 2;16(1):34. doi: 10.1186/s13021-021-00196-1.

ABSTRACT

BACKGROUND: Allometric equations are used to estimate biomass and carbon stock of forests. In Ethiopia, despite the presence of large floral diversity, only a few site-specific allometric equations have been developed so far. This study was conducted in the Omo-Gibe woodland of south-western Ethiopia to develop an allometric equation to estimate the Above-ground Biomass (AGB) of the four Acacia species (Senegalia polyacantha, Vachellia seyal, Vachellia etbaica and Vachellia tortilis). Fifty-four (54) Acacia trees were sampled and measured within 35 temporarily established square plots. In each plot, dendrometric variables were measured to derive the models based on combinations of Diameter at Breast Height (DBH), height, and wood density as predictor variables. Model performance was evaluated using goodness-of-fit statistics. The biomass was compared using four allometric biomass models that have been widely used in the tropics.

RESULTS: The model containing DBH alone was more accurate to estimate AGB compared to the use of multiple predictor variables. This study, therefore, substantiated the importance of site-specific allometric equations in estimating the AGB of Acacia woodlands. This is because a site-specific allometric equation recognizes the environmental factors, vegetation types and management practices.

CONCLUSIONS: The results of this study contribute to a better understanding of allometric equations and an accurate estimate of AGB of Acacia woodlands in Ethiopia and similar ecosystems elsewhere.

PMID:34727268 | DOI:10.1186/s13021-021-00196-1

Mol Biol Rep. 2021 Nov 2. doi: 10.1007/s11033-021-06910-z. Online ahead of print.

ABSTRACT

BACKGROUND: Signal recognition particle (SRP) promotes co-translational translocation of the proteins through or into the endoplasmic reticulum membrane and it also has elongation arrest function. SRP9 is one of the six protein subunits of SRP and functions in elongation arrest activity by forming a heterodimeric structure with SRP14. It is one of the substrates of ADAR, which has been found to have a role in breast cancer. This study was conducted to investigate the SRP9 protein expression in normal and tumor tissues of patients with breast cancer and determine its prognostic significance.

METHODS AND RESULTS: A total of 32 female patients who were diagnosed as having primary breast cancer and underwent surgery were included in the study. Western Blotting was performed to detect SRP9 protein expression levels in normal and tumor tissue samples. Clinical and pathologic characteristics were analyzed to assess the prognostic significance. SRP9 protein expression was statistically higher in the breast cancer tissue samples compared to normal matched tissue, and the mean SRP9 protein expression levels of breast cancer tissue normal tissue samples were 1.019 ± 1.011 and 0.551 ± 0.456, respectively (p = 0.001). SRP9 protein expression levels in tumor tissue of patients with lymph node metastasis, tumor size > 2 cm, estrogen receptor-positive, progesterone receptor-positive, and HER-2 negative were statistically higher than in normal tissue (p < 0.05).

CONCLUSIONS: It is vital to clarify the roles of molecules such as SRP9 in understanding the pathogenesis of breast cancer. In our study, we showed that SRP9 expression increased in breast cancer and was associated with disease-related parameters.

PMID:34727289 | DOI:10.1007/s11033-021-06910-z

Swiss Dent J. 2021 Nov 2;132(3). Online ahead of print.

ABSTRACT

Students, who may begin their dental education with sub-optimal oral self-care practices, are taught they should motivate patients to clean interdentally and reduce/stop smoking. To better understand their internalization of these concepts, students were surveyed at two distinct time points. Student cohorts from four Swiss universities were asked to complete an interdental cleaning/smoking habit questionnaire at the beginning of their pre-clinical education (n = 110) and again a year later, when beginning treatment of patients (n = 115). A local cohort (n = 28) was observed for comparison. All subjects participated voluntarily and anonymously. Interdental cleaning ≥ 3 times per week was performed by 48% first-year and 43% secondyear students in Basel, 60% and 76% in Bern, 60% and 70% in Geneva, 41% and 49% in Zurich, and 29% in the local cohort. Logistic regression using gender, class year and school as explanatory variables showed gender (p < 0.001) and school (p = 0.018) influenced cleaning frequency, with the odds being 3.16 [95% CI: 1.76, 5.67] times higher for females to perform interdental cleaning ≥ 3 times per week. Smoking was reported both years in numbers too low to analyze. Approximately 29% of the local cohort and 52% of the first-year students displayed an interdental cleaning frequency congruent with oral health recommendations. Adequate cleaning frequency increased for second-year students to 58%, which was not significant. Further study is needed to determine why more dental students do not themselves clean interdentally.

PMID:34726362

J Anim Physiol Anim Nutr (Berl). 2021 Nov 2. doi: 10.1111/jpn.13660. Online ahead of print.

ABSTRACT

This study investigates the use of nanofiber microcapsules produced by electrostatic spinning as a carrier for the delivery of lactic acid bacteria (LAB) to the intestine of ruminants. We hypothesized that the LAB encapsulated into nanofiber microcapsules can be delivered to a ruminant’s intestinal tract with little effect on the rumen fermentation and related bacteria. The in vitro experiment included three treatments: control group; 0.01g Lactobacillus acidophilus NCFM (L. acidophilus NCFM) encapsulated in nanofiber microcapsules by electrostatic spinning group (ELAN, 2.0 × 10¹¹ CFU/g); and 0.01g L. acidophilus NCFM powder group (LANP, 2.0 × 10¹¹ CFU/g), each incubated with 30 ml of buffer rumen fluid for 48h to determine the effect on rumen fermentation, then the abundance of L. acidophilus NCFM in the intestine was estimated using the modified in vitro three-step procedure. Treatment responses were statistically analysed using one-way ANOVA. The results showed that compared to the control, the ELAN group had a significant increase in pH (p < 0.05), while the LANP group had a non-significant decrease in pH (p > 0.05). LANP and ELAN groups had no significant influence on total volatile fatty acid and individual volatile fatty acids (p > 0.05), apart from isobutyric acid of both groups, which reduced (p < 0.05). ELAN group had a decreasing trend of gas production and dry matter digestion, while the LANP group increased them significantly (p < 0.05). During the 16h and 48h rumen incubation, compared with control, there was no significant change in all bacteria in the ELAN group (p > 0.05), while the LANP group increased the relative abundance levels of S. bovis, S. ruminantium, M. elsdenii, F. succinogenes, B. fibrisolvens, Lactobacillus, L. acidophilus NCFM (p < 0.05). In the intestinal part, compared with control, the relative abundance of L. acidophilus NCFM in the ELAN group increased significantly (p < 0.05), while the result was not observed in the LANP group. We concluded based on our findings that L. acidophilus NCFM could be protected by nanofiber microcapsules and delivered to the intestinal site with little influence on the rumen fermentation and bacterial community, suggesting nanofiber microcapsules prepared by electrospinning technology could be used as a carrier for rumen-protected study.

PMID:34726311 | DOI:10.1111/jpn.13660

BJU Int. 2021 Nov 2. doi: 10.1111/bju.15627. Online ahead of print.

ABSTRACT

OBJECTIVE: Evaluate long-term oncologic outcomes of patients with upper tract urothelial carcinoma (UTUC) undergoing radical nephroureterectomy (RNU) and the impact of diagnostic ureteroscopy (URS) on survival outcomes.

MATERIALS AND METHODS: A retrospective analysis of all consecutive patients undergoing RNU for suspected UTUC at a UK tertiary referral centre from a prospectively maintained database. The primary outcome measures were 5 and 10 years CSS. The secondary outcomes were: Overall Survival (OS), Recurrence Free Survival (RFS), impact of prior diagnostic URS on OS, CSS and intra-vesical Recurrence Free Survival (IV-RFS) and predictors of intra-vesical recurrence. Statistical analysis was performed in R using the ‘survminer’ and ‘survival’ packages. The Kaplan-Meier method was used to calculate survival functions and expressed in graphical form. Uni-/multivariate survival analyses were performed using the Cox proportional hazard regression model. Statistical significance in this study was set as P < 0.05 RESULTS: 422 patients underwent RNU with confirmed UTUC. The median follow-up of patients with confirmed UTUC was 9.2 (IQR:5.6yrs-12.7 yrs). The 5- and 10-year Cancer Specific survival was 70.5% [95%CI:65.9%-74.9%] and 67.1% [95%CI:62.4%-71.6%] respectively. OS and CSS were similar in diagnostic URS cohort and direct RNU cohort (OS; HR [95% CI] 1.04 [0.78-1.38]; p-0.46), (CSS; HR [95% CI] 0.96 [0.68-1.34]; p-0.81). IV-RFS was superior for the direct RNU cohort [95% CI] 1.94, [1.19-3.17]; p-0.008. On a multivariate analysis Prior URS, T2 stage, proximal ureter tumours and a prior bladder cancer history were predictors of metachronous bladder recurrence CONCLUSION: This single centre retrospective cohort study reports long-term oncological outcomes of RNU with a median follow up of 9.2 years, serving as a reference standard in counselling patients following an RNU. Stage and grade of the NU specimen were the only 2 studied factors that appeared to adversely impact long-term CSS and OS. Our results suggest that the risk of intravesical recurrence is increased nearly two-fold in patients who have had a diagnostic URS prior to RNU. Prior URS however does not appear to adversely impact long term CSS and OS. The authors would suggest that a risk-stratified approach be adopted, wherein diagnostic URS are offered only in equivocal cases.

PMID:34726325 | DOI:10.1111/bju.15627

Clin Transplant. 2021 Nov 2:e14525. doi: 10.1111/ctr.14525. Online ahead of print.

NO ABSTRACT

PMID:34726292 | DOI:10.1111/ctr.14525

J Clin Pharm Ther. 2021 Nov 2. doi: 10.1111/jcpt.13556. Online ahead of print.

ABSTRACT

WHAT IS KNOWN AND OBJECTIVES: There is clear evidence for an association between irritable bowel syndrome (IBS) and visceral hypersensitivity. This clinical study aimed to assess the adjunct role of ethosuximide, an antiepileptic drug with T-type calcium channel blocking activity, in the relieving of IBS-related abdominal pain.

METHODS: This is a prospective, 3-month, randomized and controlled study of parallel groups. Fifty outpatients who met the inclusion criteria participated in the trial. Patients were allocated randomly: 25 received mebeverine 135 mg three times daily (t.i.d), whereas the other 25 received mebeverine 135 mg t.i.d and ethosuximide 500 mg t.i.d. At baseline and 12 weeks after starting the drug, patients were evaluated by a gastroenterologist. Serum tumour necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6), interleukin-8 (IL-8), faecal myeloperoxidase and faecal neutrophile gelatinase-associated lipocalin (NGAL) levels were tested before and after treatment. The Numeric Pain Rating Scale (NRS) was assessed before and after three months of therapy.

RESULTS AND DISCUSSION: After 12 weeks, the ethosuximide group showed a statistically and significantly greater reduction in the serum levels of TNF-α, IL-6, IL-8, faecal myeloperoxidase and faecal NGAL in comparison with the control group after the treatment. Moreover, the ethosuximide group showed a statistically significant decrease in NRS compared with the mebeverine group.

WHAT IS NEW AND CONCLUSION: Ethosuximide could be a promising adjunct to antispasmodics in the treatment of IBS patients. Trial registration identifier: NCT04217733.

PMID:34726293 | DOI:10.1111/jcpt.13556

Stat Med. 2021 Nov 2. doi: 10.1002/sim.9241. Online ahead of print.

ABSTRACT

Alzheimer’s disease (AD) is an incurable and progressive disease that starts from mild cognitive impairment and deteriorates over time. Examining the effects of patients’ longitudinal cognitive decline on time to conversion to AD and obtaining a reliable diagnostic model are therefore critical to the evaluation of AD prognosis and early treatment. Previous studies either assess patients’ cognitive impairment through a single cognitive test or assume it changes linearly across time, thereby leading to an incomplete measure of cognitive decline or overlooking the subtle trajectory pattern of patients’ cognitive impairment. This study develops a new joint model to address these shortcomings. First, a dynamic factor analysis model is adopted to characterize cognitive impairment through multiple cognitive measures in a comprehensive manner. Second, a spline-based random coefficient model is proposed to reveal possibly nonlinear trajectories of patients’ cognitive decline. Finally, a proportional hazard model is considered to examine the effects of time-invariant markers and time-variant cognitive impairment on AD hazards. A Bayesian approach coupled with spline approximation techniques and MCMC methods is developed to conduct statistical inference. The application of the proposed method to the Alzheimer’s Disease Neuroimaging Initiative study provides new insights into the prevention of AD and shows a high prediction capacity of the proposed method.

PMID:34726280 | DOI:10.1002/sim.9241