Tag: statistics

Mymensingh Med J. 2021 Oct;30(4):1079-1085.

ABSTRACT

Complete assessment of obstructive jaundice requires the use of various imaging modalities that are required to detect the cause and level of obstruction thus helping in treatment planning. Magnetic Resonance Cholangio Pancreatography (MRCP) is a current available technology which is a non-invasive technique that visualizes the gallbladder, biliary tree and pancreatic duct and also provides information about surrounding structures. This study was done to correlate the MRCP findings with post-operative result and thereby demonstrate the specificity, sensitivity and efficacy of MRCP as an accurate investigatory tool for biliary obstruction. Total of fifty (50) patients of clinically diagnosed obstructive jaundice were studied from March 2017 to August 2017 in the Department of Radiology and Imaging, Combined Military Hospital, Dhaka, Bangladesh. In all these cases, USG was the initial screening investigation followed by MRCP. Cause and level of obstruction were evaluated using MRCP findings. MRCP results were correlated with surgical findings and few cases also with direct ERCP findings. Statistical analysis was done to see the sensitivity, specificity, accuracy, positive and negative predictive values of MRCP in diagnosis of biliary obstruction. In this study, USG detected level of obstruction in 56% (28 out of 50) cases. USG could detect causes of obstruction in 100% (02 out of 02) cases of choledocal cyst and 66.67% (02 out of 03) benign stricture, 60% (03 out of 05) cases of periampullary carcinoma, 57.70% (06 out of 14) cases of choledocholithiasis, and 42.86% (15 out of 26) cases of cholangiocarcinoma. On the other hand, MRCP detected level of obstruction in 98% (49 out of 50) cases. MRCP could detect causes of obstruction in 100% cases of cholangiocarcinoma, choledocholithiasis, benign stricture and choledocal cyst and 80% (04 out of 05) cases of periampullary carcinoma. In this study, ERCP could detect causes of obstruction in 32 cases of choledocholithiasis and benign stricture, but in case of cholangiocarcinoma ERCP was failed in 3 cases. In this study, for detection of cause of obstruction, ERCP had the highest sensitivity (97.79%); followed by MRCP (96.65%) and USG (60.25%). The overall diagnostic accuracy for detection of cause of obstruction was the highest for ERCP (95.50%); followed by MRCP (94.50%) and USG (64.50%). MRCP can be done in a short duration and is a noninvasive diagnostic modality compared to ERCP. MRCP needs to be advocated as a viable and non-invasive alternative with compararable sensitivity and specificity to ERCP.

PMID:34605480

Acta Crystallogr D Struct Biol. 2021 Oct 1;77(Pt 10):1282-1291. doi: 10.1107/S2059798321009475. Epub 2021 Sep 29.

ABSTRACT

In 2020, cryo-EM single-particle analysis achieved true atomic resolution thanks to technological developments in hardware and software. The number of high-resolution reconstructions continues to grow, increasing the importance of the accurate determination of atomic coordinates. Here, a new Python package and program called Servalcat is presented that is designed to facilitate atomic model refinement. Servalcat implements a refinement pipeline using the program REFMAC5 from the CCP4 package. After the refinement, Servalcat calculates a weighted F_o – F_c difference map, which is derived from Bayesian statistics. This map helps manual and automatic model building in real space, as is common practice in crystallography. The F_o – F_c map helps in the visualization of weak features including hydrogen densities. Although hydrogen densities are weak, they are stronger than in the electron-density maps produced by X-ray crystallography, and some H atoms are even visible at ∼1.8 Å resolution. Servalcat also facilitates atomic model refinement under symmetry constraints. If point-group symmetry has been applied to the map during reconstruction, the asymmetric unit model is refined with the appropriate symmetry constraints.

PMID:34605431 | DOI:10.1107/S2059798321009475

Mymensingh Med J. 2021 Oct;30(4):913-920.

ABSTRACT

Peripheral neuropathy caused by diabetes mellitus (DM) and vitamin B12 deficiency may produce overlapping clinical pictures. Metformin use is a known cause of B12 deficiency in patients with type 2 DM (T2DM). This cross-sectional comparative study was conducted at two specialized endocrine outpatient clinics in Mymensingh and Cumilla cities of Bangladesh over one year from July 2019 to June 2020. Non-pregnant adults (≥18 years of age) receiving drug treatment for T2DM for at least six months were included in this study. The study subjects were divided into two groups: those with ongoing treatment with metformin and those who never received metformin in their lifetime. Out of 99 subjects evaluated, 66 (66.7%) were in the metformin group, and 33 (33.3%) were in the non-metformin group. Subjects in the metformin group had significantly lower B12 levels compared to the non-metformin group [448.5 (343.0-570.9) vs. 549.0 (487.5-847.0) pg/mL, median (IQR), p<0.001]. None of the study subjects in the non-metformin group were either borderline deficient or deficient of B12 compared to five borderline deficient and three deficient subjects in the metformin group. Among the study subjects, 88.9% had peripheral neuropathy (PN) (43.4% mild, 21.2% moderate and 24.2% severe PN); the two groups had similar frequencies of PN. Though median serum B12 levels were lower in mild [483.0 (411.2-620.0) pg/mL], moderate [492.0 (366.5-680.0) pg/mL] and severe PN [524.5 (363.5-654.2) pg/mL] groups compared to absent PN group [540.0 (340.0-685.0) pg/mL]; the difference in B12 levels across the four groups was not statistically significant. B12 levels had weak negative correlation (r = -0.061, p = 0.624) with gram-years of metformin use. Periodic screening for serum vitamin B12 levels should be done to identify metformin-induced B12 deficiency in T2DM, especially those with PN.

PMID:34605456

Arch Esp Urol. 2021 Oct;74(8):747-751.

ABSTRACT

INTRODUCTION: The use of a temporaryor permanent catheter is very common in clinical practice. Between 15.0% and 25.0% of hospitalized patients have in-dwelling bladder catheters, the majority of which are short-term. Bladder catheter clamping before catheter removal was generally regarded as useful in the past. Today, its utility is questionable.

OBJECTIVE: To determine the association between bladder catheter clamping and spontaneous micturition or acute urinary retention (AUR) in postoperative patients with short-term indwelling bladder catheter.

MATERIALS AND METHODS: A descriptive, comparative,longitudinal study was conducted at a secondary care hospital center in a western Mexican state .AUR was the outcome variable. Two study groups wereformed: patients with bladder catheter clamping (n=43) and the control patients with no bladder catheter clamping (n=41). Descriptive statistical analyses were performed, and percentage comparisons were made with the chi-squaretest. Significant predictors were subsequently added to the multivariate model.

RESULTS: Fourteen percent (n=12) of all the study patients, with and without bladder catheter clamping, presented with AUR and 86% (n=72) did not. In the association analysis, there was no statistically significant difference between presenting with AUR and having or not having bladder catheter clamping (p=0.59). The associations of AUR with bladder re-catheterization (p=0.001), age (p=0.01), and the presence of lower urinary symptoms (p= 0.005) were statistically significant.

CONCLUSION: Postoperative bladder catheter clamping was not associated with the presence of AUR.

PMID:34605414

Arch Esp Urol. 2021 Oct;74(8):762-767.

ABSTRACT

INTRODUCTION: Prostate cancer is thesecond most common neoplasm in men. The prostate biopsy is the fundamental support for the therapeutic decision, the histopathological results of the surgical piece differ from those obtained in the diagnostic prostate biopsy generating under-staging or over-staging inpatients.

MATERIALS AND METHODS: This study collects data from a total of 147 patients who under went radicalrobot-assisted prostatectomy at the Carlos Andrade Marín Hospital in the period January 2016 to December 2018, a statistical analysis is performed by the Chisquared test with a significance level of 5%.

RESULTS: The percentage agreement of prostate biopsy with the histopathological result of the surgical piece was 49%, over-staging was 14% and under-staging was 35%. The Gleason score most commonly found in this study was 6 (3 + 3) both in prostate biopsy and in the radical prostatectomy surgical piece. There were 3 patients with vanishing prostate cancer in this study group.

CONCLUSIONS: The agreement of the prostate biopsy in relation to the surgical piece of radical prostatectomy is in the context of that reported in international studies, over staging does not represent a major health problem since patients could benefit from the radical prostatectomy but under-Staging could lead to the decision not to provide the patient a curative treatment of his disease tobe referred to an active surveillance protocol. Vanishing prostate cancer in this study group is explained by the use of hormonal blockade with leuprolideacetate prior to surgical treatment in two patients and a low tumor invasion in the histopathology sample of the third patient.

PMID:34605416

Arch Esp Urol. 2021 Oct;74(8):790-795.

ABSTRACT

OBJECTIVE: To compare systematic biopsy with MRI-TRUS fusion prostate biopsy in terms of cancer detection rates.

PATIENTS AND METHODS: The data of the patients who had a Prostate Imaging Reporting and Data System (PI-RADS) score of 3 or more lesions on mpMRI and underwent MRI-TRUS fusion biopsy with simultaneous 12-core standard systematic biopsy from June 2016 to June 2019 in our tertiary center were retrospectively reviewed. Clinical, radiological and pathological data were recorded. Statistical difference among the groups was determined by using McNemar tests.

RESULTS: A total of 344 patients were included in the study. As a result of transrectal targeted and systematic combined biopsy, 117 patients were diagnosed with prostate cancer. Benign pathology rates in patients with PI-RADS 3, PI-RADS 4, and PI-RADS 5 lesions were 93.8%, 68.5%, and 46.4%, respectively. Patients were divided into two groups as ISUP grade 1 and ISUP grade ≥2 and cancer detection rates (CDRs) were found significantly higher in transrectal targeted biopsy compared with the systematic biopsy (12.5% vs. %6.4, p=0.007 and 17.4% vs. 8.7%, p<0.001, respectively). Targeted biopsy CDRs were found significantly higher in the high PSA density group (24.5% vs. 41.4%, p=0.001) unlike the systematic biopsy.

CONCLUSION: Transrectal targeted biopsy was superior to systematic biopsy in the diagnosis of prostate cancer. Clinicians should be more selective when making a biopsy decision for patients with PI-RADS 3 lesions. PSA density can be used as a criterion for patient selection for targeted biopsy.

PMID:34605408

Arch Esp Urol. 2021 Oct;74(8):736-746.

ABSTRACT

INTRODUCTION AND OBJECTIVES: Multiple chemical sensitivity (MCS) is a multi-symptomatic systemic disease whose genitourinary symptoms are poorly known. The aim of this article is to study these symptoms in Spanish publications. MATERIALS AND METHODS: A retrospective study of descriptive type on the genitourinary symptoms of MCS is carried out in the Spanish publications between the years 2000 and 2019. The search in Medline was performed with MeSH terms “multiple chemical sensitivity Spanish” and in Google with free terms “sensibilidad química multiple España”. In the publications found, only those referring to genitourinary symptoms were selected, in which year, authors, type of article (clinical case, review, casuistry), genital symptoms, urinary symptoms, specialty, hospital or centre and city were studied. The results of these variables have been analyzed with descriptive statistics.

RESULTS: We found 45 Spanish publications on MCS of which 20 (44,4%) mentioned genitourinary symptoms. The 20 articles corresponded to 7 clinical cases, 6 reviews, 2 case series, 2 updates, 1 book chapter, 1 special article and 1 consensus document. We found 12 publications on female genital symptoms (60%), 12 on urinary symptoms (60%) and 4 on male genital symptoms (20%). The specialties with the highest number of publications were Family Medicine and Psychiatry with 3 (15%) and Neumology, Toxicology and Anesthesia and Resuscitation with 2 (10%). There are publications from 13 hospitals and 7 national centers, health agencies or foundations. The publications corresponded to 10 cities, the 2 with the most publications being Madrid with 6 (30%) and Barcelona with 6 (30%). CONCLUSIONS: The genitourinary symptoms of MCS are mentioned in about half of the Spanish publications. There is a clear predominance of these symptoms in women. This “genitourinary syndrome” should be taken into account in urological and gynecological patients with MCS.

PMID:34605413

Exp Aging Res. 2021 Oct 3:1-15. doi: 10.1080/0361073X.2021.1981096. Online ahead of print.

ABSTRACT

BACKGROUND: Online neuropsychological assessment batteries may facilitate the screening of cognitive functions in older adults and could be useful for early diagnosis and detection of cognitive impairments.

OBJECTIVE: The primary aim of this study was to assess the psychometric qualities of an online multi-domain cognitive assessment battery (General Cognitive Assessment Battery (GCAB) by Cognifit™) applied for the first time in Bulgaria.

METHODS: A total of 20 healthy older adults (6 male and 14 female, aged 60-82) completed the GCAB as well as the Mini-Mental State Examination (MMSE) and the Consortium to Establish a Registry for Alzheimer’s Disease (CERAD) neuropsychological battery. Descriptive statistics were used to describe the demographic characteristics of the sample and the scores on the GCAB and the CERAD battery. The internal consistency of the GCAB was evaluated using item analysis and measured with Cronbach’s alpha. The concurrent validity of the GCAB was assessed with respect to the CERAD using Spearman’s r after verifying the linear relationship between the GCAB and CERAD scores.

RESULTS: The GCAB showed good concurrent validity when compared with the corresponding CERAD tests. The correlation coefficients ranged from 0.67 for working memory to 0.47 for short-term auditory memory. We found very good reliability of the GCAB, with the inter-class correlation coefficient higher than 0.8 for all cognitive domains. There were no significant correlations between MMSE and GCAB scores.

CONCLUSION: The GCAB was found to be valid for the cognitive screening of Bulgarian healthy older adults and may provide an adequate assessment of their cognitive status. The GCAB showed good concurrent validity when compared with the CERAD battery, measuring similar cognitive constructs. Further work is necessary to explore its validity and reliability.

PMID:34605370 | DOI:10.1080/0361073X.2021.1981096

Clin Nephrol. 2021 Oct 4. doi: 10.5414/CN110273. Online ahead of print.

ABSTRACT

BACKGROUND: Iodinated contrast medium exposure is associated with acute kidney injury (AKI). Patients with severe contrast-induced AKI (CI-AKI) may need renal replacement therapy (RRT). Prediction models exist for CI-AKI, but few need RRT. We aimed to establish a preprocedural score model to stratify patients at risk of unplanned postprocedural RRT following invasive coronary angiography (ICA) or percutaneous coronary intervention (PCI).

METHODS AND RESULTS: Between January 2010 and December 2015, a series of 3,469 patients were randomly divided into two cohorts at a 2 : 1 ratio for model development and validation, respectively. A total of 36 patients (1.0%) needed unplanned postprocedural RRT following ICA and/or PCI. Multivariable logistic regression was used to build the risk model. C-statistic and Hosmer-Lemeshow tests were used to evaluate the performance of the model. Five preprocedural variables – independently associated with unplanned postprocedural RRT – were identified as factors of the risk score model with different scores: age > 75 years (1), serum creatinine level ≥ 1.5 mg/dL (1), diabetes mellitus (1), hypotension (2), and acute myocardial infarction (2). The risk score model was demonstrated with high discrimination (C-statistic = 0.872) and goodness of fit (χ2 = 3.769, p = 0.438). Furthermore, the model allowed a hierarchical classification of low, intermediate, and high risk, within which the observed unplanned RRT rates were ~ 0.4, 3.0, and 20.0%, respectively.

CONCLUSION: Using preprocedural variables, we developed and validated a risk model for unplanned postprocedural RRT following ICA and/or PCI.

PMID:34605397 | DOI:10.5414/CN110273

Neuroradiol J. 2021 Oct 3:19714009211047455. doi: 10.1177/19714009211047455. Online ahead of print.

ABSTRACT

OBJECTIVE: To correlate dual energy computed tomography electron density measurements with histopathological cerebral glioma grading to determine whether it can be used as a non-invasive predictor of cerebral glioma grade.

MATERIALS AND METHODS: Fifty patients with suspected cerebral gliomas on imaging scheduled to undergo resection were included. We tested our hypothesis that with increasing glioma grade, increased tumor cellularity should translate into increased electron density and if a statistically significant difference between electron density of low-grade gliomas and high-grade gliomas is seen, we may have a clinical use of dual energy computed tomography as a non-invasive tool to predict cerebral glioma grade.A pre-operative dual energy computed tomography scan of the brain was performed, and electron density measurements calculated from the solid part of the tumor. Obtaining a ratio with electron density of contralateral normal brain parenchyma normalized these values. The minimum, maximum and mean electron density and their normalized values recorded between high-grade gliomas and low-grade gliomas were compared for presence of statistical significance.

RESULTS: A statistically significant difference was found between all six parameters recorded (minimum electron density and normalized values, mean electron density and normalized values, maximum electron density and normalized values) between low-grade gliomas and high-grade gliomas. The predictivity ranged from 75% (for minimum electron density and maximum normalized values) to 81.25% (for mean normalized values). All six parameters were found to have statistically significant positive correlation with Ki-67 index.

CONCLUSION: Dual energy computed tomography electron density measurements in cerebral gliomas are predictive of pre-operative differentiation of low-grade gliomas from high-grade gliomas and show a linear, statistically significant positive correlation with Ki-67 index.

PMID:34605334 | DOI:10.1177/19714009211047455