Tag: pubmed

Gesundheitswesen. 2021 Sep;83(8-09):e41-e48. doi: 10.1055/a-1531-5507. Epub 2021 Sep 8.

ABSTRACT

OBJECTIVE: Well-established mortality ratio methodology can contribute to a fuller picture of the SARS-CoV-2/COVID-19 burden of disease by revealing trends and informing mitigation strategies. This work examines respective data from Germany by way of example.

METHODS: Using monthly and weekly all-cause mortality data from January 2016 to June 2020 (published by the German Federal Statistical Institute) for all ages,<65 years and≥65 years, and specified for Germany’s federal states, we explored mortality as sequela of COVID-19. We analysed standardized mortality ratios (SMRs) comparing 2020 with 2016-2019 as reference years with a focus on trend detection.

RESULTS: In Germany as a whole, elevated mortality in April (most pronounced for Bavaria) declined in May. The states of Hamburg and Bremen had increased SMRs in all months under study. In Mecklenburg-Western Pomerania, decreased SMRs in January turned monotonically to increased SMRs by June. Irrespective of age group, this trend was pronounced and significant.

CONCLUSIONS: Increased SMRs in Hamburg and Bremen must be interpreted with caution because of potential upward distortions due to a “catchment bias”. A pronounced excess mortality in April across Germany was confirmed and a hitherto undetected trend of increasing SMRs for Mecklenburg-Western Pomerania was revealed. To meet the pandemic challenge and to benefit from research based on data collected in standardized ways, national authorities should regularly conduct SMR analyses. For independent analyses, national authorities should also expedite publishing raw mortality and population data, including detailed information on age, sex, and cause of death, in the public domain.

PMID:34496443 | DOI:10.1055/a-1531-5507

Neural Comput. 2021 May 13;33(6):1656-1697. doi: 10.1162/neco_a_01384.

ABSTRACT

We develop in this letter a framework of empirical gain maximization (EGM) to address the robust regression problem where heavy-tailed noise or outliers may be present in the response variable. The idea of EGM is to approximate the density function of the noise distribution instead of approximating the truth function directly as usual. Unlike the classical maximum likelihood estimation that encourages equal importance of all observations and could be problematic in the presence of abnormal observations, EGM schemes can be interpreted from a minimum distance estimation viewpoint and allow the ignorance of those observations. Furthermore, we show that several well-known robust nonconvex regression paradigms, such as Tukey regression and truncated least square regression, can be reformulated into this new framework. We then develop a learning theory for EGM by means of which a unified analysis can be conducted for these well-established but not fully understood regression approaches. This new framework leads to a novel interpretation of existing bounded nonconvex loss functions. Within this new framework, the two seemingly irrelevant terminologies, the well-known Tukey’s biweight loss for robust regression and the triweight kernel for nonparametric smoothing, are closely related. More precisely, we show that Tukey’s biweight loss can be derived from the triweight kernel. Other frequently employed bounded nonconvex loss functions in machine learning, such as the truncated square loss, the Geman-McClure loss, and the exponential squared loss, can also be reformulated from certain smoothing kernels in statistics. In addition, the new framework enables us to devise new bounded nonconvex loss functions for robust learning.

PMID:34496383 | DOI:10.1162/neco_a_01384

Neural Comput. 2021 May 13;33(6):1572-1615. doi: 10.1162/neco_a_01381.

ABSTRACT

An emerging paradigm proposes that neural computations can be understood at the level of dynamic systems that govern low-dimensional trajectories of collective neural activity. How the connectivity structure of a network determines the emergent dynamical system, however, remains to be clarified. Here we consider a novel class of models, gaussian-mixture, low-rank recurrent networks in which the rank of the connectivity matrix and the number of statistically defined populations are independent hyperparameters. We show that the resulting collective dynamics form a dynamical system, where the rank sets the dimensionality and the population structure shapes the dynamics. In particular, the collective dynamics can be described in terms of a simplified effective circuit of interacting latent variables. While having a single global population strongly restricts the possible dynamics, we demonstrate that if the number of populations is large enough, a rank R network can approximate any R-dimensional dynamical system.

PMID:34496384 | DOI:10.1162/neco_a_01381

J Cogn Neurosci. 2021 Jul 1;33(8):1549-1562. doi: 10.1162/jocn_a_01735.

ABSTRACT

Our understanding of the sensory environment is contextualized on the basis of prior experience. Measurement of auditory ERPs provides insight into automatic processes that contextualize the relevance of sound as a function of how sequences change over time. However, task-independent exposure to sound has revealed that strong first impressions exert a lasting impact on how the relevance of sound is contextualized. Dynamic causal modeling was applied to auditory ERPs collected during presentation of alternating pattern sequences. A local regularity (a rare p = .125 vs. common p = .875 sound) alternated to create a longer timescale regularity (sound probabilities alternated regularly creating a predictable block length), and the longer timescale regularity changed halfway through the sequence (the regular block length became shorter or longer). Predictions should be revised for local patterns when blocks alternated and for longer patterning when the block length changed. Dynamic causal modeling revealed an overall higher precision for the error signal to the rare sound in the first block type, consistent with the first impression. The connectivity changes in response to errors within the underlying neural network were also different for the two blocks with significantly more revision of predictions in the arrangement that violated the first impression. Furthermore, the effects of block length change suggested errors within the first block type exerted more influence on the updating of longer timescale predictions. These observations support the hypothesis that automatic sequential learning creates a high-precision context (first impression) that impacts learning rates and updates to those learning rates when predictions arising from that context are violated. The results further evidence automatic pattern learning over multiple timescales simultaneously, even during task-independent passive exposure to sound.

PMID:34496376 | DOI:10.1162/jocn_a_01735

J Cogn Neurosci. 2021 Jul 1;33(8):1397-1412. doi: 10.1162/jocn_a_01738.

ABSTRACT

Objects are grouped into categories through a complex combination of statistical and structural regularities. We sought to better understand the neural responses to the structural features of object categories that result from implicit learning. Adult participants were exposed to 32 object categories that contained three structural properties: frequency, variability, and co-occurrences, during an implicit learning task. After this exposure, participants completed a recognition task and were then presented with blocks of learned object categories during fMRI sessions. Analyses were performed by extracting data from ROIs placed throughout the fusiform gyri and lateral occipital cortex and comparing the effects of the different structural properties throughout the ROIs. Behaviorally, we found that symbol category recognition was supported by frequency, but not variability. Neurally, we found that sensitivity to object categories was greater in the right hemisphere and increased as ROIs were moved posteriorly. Frequency and variability altered the brain activation while processing object categories, although the presence of learned co-occurrences did not. Moreover, variability and co-occurrence interacted as a function of ROI, with the posterior fusiform gyrus being most sensitive to this relationship. This result suggests that variability may guide the learner to relevant co-occurrences and this is supported by the posterior ventral temporal cortex. Broadly, our results suggest that the internal features of the categories themselves are key factors in the category learning system.

PMID:34496382 | DOI:10.1162/jocn_a_01738

Am J Nephrol. 2021 Sep 8:1-13. doi: 10.1159/000517619. Online ahead of print.

ABSTRACT

INTRODUCTION: Transforming growth factor-β1 (TGF-β1) is a multifunctional cytokine, with diverse roles in fibrosis and inflammation, which acts through Smad signaling in renal pathology. We intended to investigate the expression of TGF-β/Smad signaling in glomerulonephritis (GN) and to assess its role as risk factor for progression to chronic kidney disease (CKD).

METHODS: We evaluated the immunohistochemical expression of TGF-β1, phosphorylated Smad3 (pSmad3), and Smad7 semiquantitatively and quantitatively using computerized image analysis program in different compartments of 50 renal biopsies with GN, and the results were statistically analyzed with clinicopathological parameters. We also examined the associations among their expressions, the impact of their co-expression, and their role in progression to CKD.

RESULTS: TGF-β1 expression correlated positively with segmental glomerulosclerosis (p= 0.025) and creatinine level at diagnosis (p = 0.002), while pSmad3 expression with interstitial inflammation (p = 0.024). In glomerulus, concomitant expressions of high Smad7 and medium pSmad3 were observed to be correlated with renal inflammation, such as cellular crescent (p = 0.011), intense interstitial inflammation (p = 0.029), and lower serum complement (C) 3 (p = 0.028) and C4 (p = 0.029). We also reported a significant association between pSmad3 expression in glomerular endothelial cells of proliferative GN (p = 0.045) and in podocytes of nonproliferative GN (p = 0.005). Finally, on multivariate Cox-regression analysis, TGF-β1 expression (hazard ratio = 6.078; 95% confidence interval: 1.168-31.627; p = 0.032) was emerged as independent predictor for CKD.

DISCUSSION/CONCLUSION: TGF-β1/Smad signaling is upregulated with specific characteristics in different forms of GN. TGF-β1 expression is indicated as independent risk factor for progression to CKD, while specific co-expression pattern of pSmad3 and Smad7 in glomerulus is correlated with renal inflammation.

PMID:34496361 | DOI:10.1159/000517619

Oncol Res Treat. 2021 Sep 8:1-9. doi: 10.1159/000519000. Online ahead of print.

ABSTRACT

INTRODUCTION: Chemotherapy-induced peripheral neuropathy (CIPN) is a common side effect persisting after completion of neurotoxic chemotherapies. This observational study was designed to evaluate the effectiveness of the dietary supplement OnLife® (patented mixture of specific fatty acids and palmitoylethanolamide) in improving symptoms of CIPN in breast and colon cancer patients.

METHODS: Improvement of CIPN was evaluated in adult patients, previously treated with (neo)adjuvant paclitaxel- (breast cancer) or oxaliplatin-based (colon cancer) therapies, receiving OnLife® for 3 months after completion of chemotherapy. The primary endpoint was to compare the severity of peripheral sensory neuropathy (PSN) and peripheral motor neuropathy (PMN) before and at the end of OnLife® treatment. Secondary endpoints included the assessment of patient-reported quality of life and CIPN symptoms as assessed by questionnaires.

RESULTS: 146 patients (n = 75 breast cancer patients and n = 71 colon cancer patients) qualified for analysis; 31.1% and 37.5% of breast cancer patients had an improvement of PSN and PMN, respectively. In colon cancer patients, PSN and PMN improved in 16.9% and 20.0% of patients, respectively. According to patient-reported outcomes, 45.9% and 37.5% of patients with paclitaxel-induced PSN and PMN, and 23.9% and 22.0% of patients with oxaliplatin-induced PSN and PMN experienced a reduction of CIPN symptoms, respectively.

CONCLUSION: OnLife® treatment confirmed to be beneficial in reducing CIPN severity and in limiting the progression of neuropathy, more markedly in paclitaxel-treated patients and also in patients with oxaliplatin-induced CIPN.

PMID:34496363 | DOI:10.1159/000519000

Schizophr Res. 2021 Sep 5;236:123-134. doi: 10.1016/j.schres.2021.08.005. Online ahead of print.

ABSTRACT

BACKGROUND: As the burden of treatment-resistant schizophrenia (TRS) on patients and society is high it is important to identify predictors of response to medications in TRS. The aim was to analyse whether baseline patient and study characteristics predict treatment response in TRS in drug trials.

METHODS: A comprehensive search strategy completed in PubMed, Cochrane and Web of Science helped identify relevant studies. The studies had to meet the following criteria: English language clinical trial of pharmacological treatment of TRS, clear definition of TRS and response, percentage of response reported, at least one baseline characteristic presented, and total sample size of at least 15. Meta-regression techniques served to explore whether baseline characteristics predict response to medication in TRS.

RESULTS: 77 articles were included in the systematic review. The overall sample included 7546 patients, of which 41% achieved response. Higher positive symptom score at baseline predicted higher response percentage. None of the other baseline patient or study characteristics achieved statistical significance at predicting response. When analysed in groups divided by antipsychotic drugs, studies of clozapine and other atypical antipsychotics produced the highest response rate.

CONCLUSIONS: This meta-analytic review identified surprisingly few baseline characteristics that predicted treatment response. However, higher positive symptoms and the use of atypical antipsychotics – particularly clozapine -was associated with the greatest likelihood of response. The difficulty involved in the prediction of medication response in TRS necessitates careful monitoring and personalised medication management. There is a need for more investigations of the predictors of treatment response in TRS.

PMID:34496316 | DOI:10.1016/j.schres.2021.08.005

Early Hum Dev. 2021 Aug 30;161:105454. doi: 10.1016/j.earlhumdev.2021.105454. Online ahead of print.

ABSTRACT

BACKGROUND: Preterm children obtain worse scores in tests that evaluate visuospatial functions. Pascual’s graphomotor test (PGMt) assesses maturity in copying drawings in childhood, quickly evaluating the graphomotor aptitude that is a partial aspect of non-verbal intelligence.

AIMS: To evaluate visuospatial functions in preterm children compared to full-term children. To assess the capacity of the Pascual graphomotor test (PGMt) to detect visuospatial disorders more specifically than non-verbal intelligence quotient (IQ).

STUDY DESIGN AND SUBJECTS: case and control study.

CASES: preterm children between 5 and 11 years of age without cognitive delay; controls: full-term children with the same characteristics. For each child clinical history, neurological examination, language-free intelligence test Toni 2 (IQ) and Pascual’s graphomotor test (PGMt) were carried out.

RESULTS: 135 children were enrolled (59 cases vs. 79 controls). The mean age was 7.4 years. 55% were male. The mean gestational age of cases was 30.5 weeks with 34% extremely preterm. Cases obtained worse mean scores in both tests. The mean IQ scores were: cases 117.4, controls 125.0 (p = 0.004). The mean graphomotor quotient (GQ) scores were statistically and clinically significant (cases 76.8; controls 98.3, p = 0.001). Although we have found a positive correlation between IQ and GQ scores (cc = 0.31 p = 0.01), the differences found in the GQ between groups have been maintained regardless of the IQ in the multivariate analysis (GQ: cases 78.3 (SD 14.8), controls 98.3 (SD 12.5), p = 0.04).

CONCLUSIONS: GQ is a useful tool for screening for visuospatial anomalies. GQ more specifically measures the visuoperceptive disorder regardless of non-verbal cognitive level.

PMID:34496347 | DOI:10.1016/j.earlhumdev.2021.105454

J Oral Maxillofac Surg. 2021 Aug 10:S0278-2391(21)00754-0. doi: 10.1016/j.joms.2021.08.002. Online ahead of print.

ABSTRACT

PURPOSE: Coronoidectomy is carried out frequently as a part of the cranial-maxillofacial surgery procedure. There are few articles on the fate of coronoid process after coronoidectomy, except that several case reports mentioned that coronoid process had regenerated. This study aimed to radiographically access the anatomic outcomes of coronoid process and investigate which factors were associated with the outcomes after coronoidectomy.

MATERIALS AND METHODS: A retrospective cohort study included patients undergoing coronoidectomy over a 7-year period. The primary outcome variable was the new coronoid process occurrence (yes/no). Secondary outcome variable was the type of the new coronoid process by evaluating its size, shape and position. Radiograph at 1-year postoperative visit was used to determine the outcomes. The predictor variables included age, sex, surgical purpose, surgical side, surgical approach and the maximal interincisal opening. Appropriate statistics were analyzed by SPSS version 22. χ² test and binary logistic regression were used to assess the association between predictor factors and anatomic outcomes (P <.05).

RESULTS: The study sample included 57 patients. In total, 96 coronoidectomies were performed. Seventy-four coronoid processes (77.1%) showed complete (n = 44, 45.8%), nonunion (n = 19, 19.8%) or partial (n = 11, 11.5%) regrowth, whereas no evidence of regeneration in 22 sites was observed radiographically at 1-year postoperative visit. Binary logistic regression showed that a young age (odds ratio 0.704; 95% confidence interval 0.562-0.882; P = .002) was significantly associated with regeneration of coronoid process.

CONCLUSIONS: Coronoid process can mostly regenerate after coronoidectomy. A young age may contribute to regrowth of coronoid process.

PMID:34496291 | DOI:10.1016/j.joms.2021.08.002