Refining the hospitalization rate: A mixed methods approach to differentiate primary COVID-19 from incidental cases.

Purpose: Until now, the Hospitalization Rate (HR) served as an indicator (among others) for the COVID-19 associated healthcare burden. To ensure that the HR accomplishes its full potential, hospitalizations caused by COVID-19 (primary cases) and hospitalizations of patients with incidental positive SARS-CoV-2 test results (incidental cases) must be differentiated. The aim of this study was to synthesize the existing evidence on differentiation criteria between hospitalizations of primary cases and incidental cases. Methods: An online survey of the members of the German Network University Medicine (NUM) was conducted. Additionally, senior clinicians with expertise in COVID-19 care were invited for qualitative, semi-structured interviews. Furthermore, a rapid literature review was undertaken on publications between 03/2020 and 12/2022. Results: In the online survey (n=30, response rate 56%), pneumonia and acute upper respiratory tract infections were the most indicative diagnoses for a primary case. In contrast, malignant neoplasms and acute myocardial infarctions were most likely to be associated with incidental cases. According to the experts (n=6), the diagnosis, ward, and type of admission (emergency or elective), low oxygen saturation, need for supplemental oxygen, and initiation of COVID-19 therapy point to a primary case. The literature review found that respiratory syndromes and symptoms, oxygen support, and elevated levels of inflammatory markers were associated with primary cases. Conclusion: There are parameters for the differentiation of primary from incidental cases to improve the objective of the HR. Ultimately, an updated HR has the potential to serve as a more accurate indicator of the COVID-19 associated healthcare burden.

Bilingualism yields language-specific plasticity in left hemisphere's circuitry for learning to read in young children.

How does bilingual exposure impact children's neural circuitry for learning to read? Theories of bilingualism suggests that exposure to two languages may yield a functional and neuroanatomical adaptation to support the learning of two languages (Klein et al., 2014). To test the hypothesis that this neural adaptation may vary as a function of structural and orthographic characteristics of bilinguals' two languages, we compared Spanish-English and French-English bilingual children, and English monolingual children, using functional Near Infrared Spectroscopy neuroimaging (fNIRS, ages 6-10, N =26). Spanish offers consistent sound-to-print correspondences ("phonologically transparent" or "shallow"); such correspondences are more opaque in French and even more opaque in English (which has both transparent and "phonologically opaque" or "deep" correspondences). Consistent with our hypothesis, both French- and Spanish-English bilinguals showed hyperactivation in left posterior temporal regions associated with direct sound-to-print phonological analyses and hypoactivation in left frontal regions associated with assembled phonology analyses. Spanish, but not French, bilinguals showed a similar effect when reading Irregular words. The findings inform theories of bilingual and cross-linguistic literacy acquisition by suggesting that structural characteristics of bilinguals' two languages and their orthographies have a significant impact on children's neuro-cognitive architecture for learning to read.

Designing optical free-form surfaces for extended sources.

LED lighting has been a strongly growing field for the last decade. The outstanding features of LED, like compactness and low operating temperature take the control of light distributions to a new level. Key for this is the development of sophisticated optical elements that distribute the light as intended. The optics design method known as tailoring relies on the point source assumption. This assumption holds as long as the optical element is large compared to the LED chip. With chip sizes of 1 mm² this is of no concern if each chip is endowed with its own optic. To increase the power of a luminaire, LED chips are arranged to form light engines that reach several cm in diameter. In order to save costs and space it is often desirable to use a single optical element for the light engine. At the same time the scale of the optics must not be increased in order to trivially keep the point source assumption valid. For such design tasks point source algorithms are of limited usefulness. New methods that take into account the extent of the light source have to be developed. We present two such extended source methods. The first method iteratively adapts the target light distribution that is fed into a points source method while the second method employs a full phase space description of the optical system.

The "Perceptual Wedge Hypothesis" as the basis for bilingual babies' phonetic processing advantage: new insights from fNIRS brain imaging.

In a neuroimaging study focusing on young bilinguals, we explored the brains of bilingual and monolingual babies across two age groups (younger 4-6 months, older 10-12 months), using fNIRS in a new event-related design, as babies processed linguistic phonetic (Native English, Non-Native Hindi) and non-linguistic Tone stimuli. We found that phonetic processing in bilingual and monolingual babies is accomplished with the same language-specific brain areas classically observed in adults, including the left superior temporal gyrus (associated with phonetic processing) and the left inferior frontal cortex (associated with the search and retrieval of information about meanings, and syntactic and phonological patterning), with intriguing developmental timing differences: left superior temporal gyrus activation was observed early and remained stably active over time, while left inferior frontal cortex showed greater increase in neural activation in older babies notably at the precise age when babies' enter the universal first-word milestone, thus revealing a first-time focal brain correlate that may mediate a universal behavioral milestone in early human language acquisition. A difference was observed in the older bilingual babies' resilient neural and behavioral sensitivity to Non-Native phonetic contrasts at a time when monolingual babies can no longer make such discriminations. We advance the "Perceptual Wedge Hypothesis" as one possible explanation for how exposure to greater than one language may alter neural and language processing in ways that we suggest are advantageous to language users. The brains of bilinguals and multilinguals may provide the most powerful window into the full neural "extent and variability" that our human species' language processing brain areas could potentially achieve.

Overlapping gene expression profiles of cell migration and tumor invasion in human bladder cancer identify metallothionein 1E and nicotinamide N-methyltransferase as novel regulators of cell migration.

Cell migration is essential to cancer invasion and metastasis and is spatially and temporally integrated through transcriptionally dependent and independent mechanisms. As cell migration is studied in vitro, it is important to identify genes that both drive cell migration and are biologically relevant in promoting invasion and metastasis in patients with cancer. Here, gene expression profiling and a high-throughput cell migration system answers this question in human bladder cancer. In vitro migration rates of 40 microarray-profiled human bladder cancer cell lines were measured by radial migration assay. Genes whose expression was either directly or inversely associated with cell migration rate were identified and subsequently evaluated for their association with cancer stage in 61 patients. This analysis identified genes known to be associated with cell invasion such as versican, and novel ones, including metallothionein 1E (MT1E) and nicotinamide N-methyltransferase (NNMT), whose expression correlated positively with cancer cell migration and tumor stage. Using loss of function analysis, we show that MT1E and NNMT are necessary for cancer cell migration. These studies provide a general approach to identify the clinically relevant genes in cancer cell migration and mechanistically implicate two novel genes in this process in human bladder cancer.

Molecular targets of glioma invasion.

Glioblastoma multiforme is the most common and lethal primary malignant brain tumor. Although considerable progress has been made in technical proficiencies of surgical and radiation treatment for brain tumor patients, the impact of these advances on clinical outcome has been disappointing, with median survival time not exceeding 15 months. Over the last 30 years, no significant increase in survival of patients suffering from this disease has been achieved. A fundamental source of the management challenge presented in glioma patients is the insidious propensity of tumor invasion into distant brain tissue. Invasive tumor cells escape surgical removal and geographically dodge lethal radiation exposure and chemotherapy. Recent improved understanding of biochemical and molecular determinants of glioma cell invasion provide valuable insight into the underlying biological features of the disease, as well as illuminating possible new therapeutic targets. These findings are moving forward to translational research and clinical trials as novel antiglioma therapies.

A knowledge based approach for representing and reasoning about signaling networks.

MOTIVATION: In this paper we propose to use recent developments in knowledge representation languages and reasoning methodologies for representing and reasoning about signaling networks. Our approach is different from most other qualitative systems biology approaches in that it is based on reasoning (or inferencing) rather than simulation. Some of the advantages of our approach are, we can use recent advances in reasoning with incomplete and partial information to deal with gaps in signal network knowledge; and can perform various kinds of reasoning such as planning, hypothetical reasoning and explaining observations. RESULTS: Using our approach we have developed the system BioSigNet-RR for representation and reasoning about signaling networks. We use a NFkappaB related signaling pathway to illustrate the kinds of reasoning and representation that our system can currently do. AVAILABILITY: The system is available on the Web at http://www.public.asu.edu/~cbaral/biosignet

Cost of migration: invasion of malignant gliomas and implications for treatment.

Tumors of glial origin consist of a core mass and a penumbra of invasive, single cells, decreasing in numbers towards the periphery and still detectable several centimeters away from the core lesion. Several decades ago, the diffuse nature of malignant gliomas was recognized by neurosurgeons when super-radical resections using hemispherectomies failed to eradicate these tumors. Local invasiveness eventually leads to regrowth of a recurrent tumor predominantly adjacent to the resection cavity, which is not significantly altered by radiation or chemotherapy. This raises the question of whether invasive glioma cells activate cellular programs that render these cells resistant to conventional treatments. Clinical and experimental data demonstrate that glioma invasion is determined by several independent mechanisms that facilitate the spread of these tumors along different anatomic and molecular structures. A common denominator of this cellular behavior may be cell motility. Gene-expression profiling showed upregulation of genes related to motility, and functional studies demonstrated that cell motility contributes to the invasive phenotype of malignant gliomas. There is accumulating evidence that invasive glioma cells show a decreased proliferation rate and a relative resistance to apoptosis, which may contribute to chemotherapy and radiation resistance. Interestingly, interference with cell motility by different strategies results in increased susceptibility to apoptosis, indicating that this dynamic relationship can potentially be exploited as an anti-invasive treatment paradigm. In this review, we discuss mechanisms of glioma invasion, characteristics of the invasive cell, and consequences of this cellular phenotype for surgical resection, oncologic treatments, and future perspectives for anti-invasive strategies.

[A concept for the assessment of quality of life in patients with carcinomas of the upper aerodigestive tract]. / Konzept zur Erhebung der Lebensqualität bei Patienten mit Karzinomen des oberen Aerodigestivtraktes.

BACKGROUND: The quality of life (QoL) of patients with malignant diseases decreases significantly. OBJECTIVE: The evaluation of QoL is generally not part of the management of patients with head and neck cancer. The aim of this study was to develop an additional disease- and treatment-specific questionnaire to evaluate QoL in surgically treated head and neck cancer patients. PATIENTS AND METHODS: The general QoL was evaluated with the QLQ-C30 questionnaire developed by the European Organisation of Research and Treatment of Cancer (EORTC). RESULTS: The disease-specific QoL was evaluated using the EORTC H&N35 module. The new questionnaire "Kiel Head and Neck 17" (KQL H&N-17) is a disease- and treatment-specific addition especially in regard to side effects caused by surgical treatment. CONCLUSIONS: A wide application of this whole concept is needed to obtain comparable results from studies suitable for evaluating QoL in patients receiving different treatments for their malignant diseases. Moreover, the effectiveness and quality of treatment could be controlled better, which would help to increase the QoL of these patients.

Glioma cell motility is associated with reduced transcription of proapoptotic and proliferation genes: a cDNA microarray analysis.

Microarray analysis of complementary DNA (cDNA) allows large-scale, comparative, gene expression profiling of two different cell populations. This approach has the potential for elucidating the primary transcription events and genetic cascades responsible for increased glioma cell motility in vitro and invasion in vivo. These genetic determinants could become therapeutic targets. We compared cDNA populations of a glioma cell line (G112) exposed or not to a motility-inducing substrate of cell-derived extracellular matrix (ECM) proteins using two sets of cDNA microarrays of 5,700 and 7,000 gene sequences. The data were analyzed considering the level and consistency of differential expression (outliers) and whether genes involved in pathways of motility, apoptosis, and proliferation were differentially expressed when the motility behavior was engaged. Validation of differential expression of selected genes was performed on additional cell lines and human glioblastoma tissue using quantitative RT-PCR. Some genes involved in cell motility, like tenascin C, neuropilin 2, GAP43, PARG1 (an inhibitor of Rho), PLCy, and CD44, were over expressed; other genes, like adducin 3y and integrins, were down regulated in migrating cells. Many key cell cycle components, like cyclin A and B, and proliferation markers, like PCNA, were strongly down regulated on ECM. Interestingly, genes involved in apoptotic cascades, like Bcl-2 and effector caspases, were differentially expressed, suggesting the global down regulation of proapoptotic components in cells exposed to cell-derived ECM. Overall, our findings indicate a reduced proliferative and apoptotic activity of migrating cells. cDNA microarray analysis has the potential for uncovering genes linking the phenotypic aspects of motility, proliferation, and apoptosis.

Death-associated protein 3 (Dap-3) is overexpressed in invasive glioblastoma cells in vivo and in glioma cell lines with induced motility phenotype in vitro.

PURPOSE: To discover the genetic determinants of glioma invasion in vivo, we compared the mRNA expression profiles of glioblastoma cells residing at the tumor core versus those at the invasive rim of a human tumor resection. EXPERIMENTAL DESIGN: From a single glioblastoma specimen, 20,000 individual cells from each region (core and invasive rim) were collected by laser capture microdissection and analyzed by mRNA differential display. Differential expression of gene candidates was confirmed by laser capture microdissection and quantitative reverse transcription-PCR in additional glioblastoma multiforme specimens, and the role in migration was further evaluated in glioma cell lines in vitro. RESULTS: Reproducible overexpression the death-associated Protein 3 (Dap-3) mRNA (NM 004632, GenBank; also reported as human ionizing resistance conferring protein mRNA, HSU18321, GenBank) by invasive cells was identified. Although the full-length Dap-3 protein has been described as proapoptotic, the NH(2)-terminal fragment can act in a dominant negative way resulting in protection from programmed cell death. In glioma cell lines T98G and G112 with an induced motility phenotype, Dap-3 was up-regulated at the mRNA and protein level as assessed by quantitative reverse transcription-PCR, cDNA microarray, and Western blot analysis. These cells showed an increased resistance to undergo camptothecin-induced apoptosis, which was overcome by effective Dap-3-antisense treatment. Antisense treatment also decreased the migration ability of T98G cells. CONCLUSIONS: Dap-3 is up-regulated in invasive glioblastoma multiforme cells in vivo and in glioma cells with an induced motility phenotype in vitro. When migration is activated, Dap-3 is up-regulated and cells become resistant to apoptosis. These findings suggest that Dap-3 confers apoptosis-resistance when migration behavior is engaged.

Pattern of self-organization in tumour systems: complex growth dynamics in a novel brain tumour spheroid model.

We propose that a highly malignant brain tumour is an opportunistic, self-organizing and adaptive complex dynamic biosystem rather than an unorganized cell mass. To test the hypothesis of related key behaviour such as cell proliferation and invasion, we have developed a new in vitro assay capable of displaying several of the dynamic features of this multiparameter system in the same experimental setting. This assay investigates the development of multicellular U87MGmEGFR spheroids in a specific extracellular matrix gel over time. The results show that key features such as volumetric growth and cell invasion can be analysed in the same setting over 144 h without continuously supplementing additional nutrition. Moreover, tumour proliferation and invasion are closely correlated and both key features establish a distinct ratio over time to achieve maximum cell velocity and to maintain the system's temporo-spatial expansion dynamics. Single cell invasion follows a chain-like pattern leading to the new concept of a intrabranch homotype attraction. Since preliminary studies demonstrate that heterotype attraction can specifically direct and accelerate the emerging invasive network, we further introduce the concept of least resistance, most permission and highest attraction as an essential principle for tumour invasion. Together, these results support the hypothesis of a self-organizing adaptive biosystem.

Identification and validation of P311 as a glioblastoma invasion gene using laser capture microdissection.

The mRNA expression profiles from glioblastoma cells residing at the tumor core and invasive rim of a human tumor resection were compared. From a single tumor specimen, 20,000 single cells from each region were collected by laser capture microdissection. Differential expression of 50-60 cDNA bands was detected. One of the sequences overexpressed by the invasive cells showed 99% homology to the P311 gene, the protein product of which is reported to localize at focal adhesions. Relative overexpression of P311 by invading glioblastoma cells compared with tumor core was confirmed by quantitative reverse transcription-PCR of six glioblastoma specimens after laser capture microdissection collection of rim and core cells. In vitro studies using antisense oligodeoxynucleotides and integrin activation confirmed the role of P311 in supporting migration of malignant glioma cells. Immunochemistry studies confirmed the presence of the P311 protein in tumor cells, particularly at the invasive edge of human glioblastoma specimens.

Migration and invasion in brain neoplasms.

Local invasion of the brain by neoplastic glial cells is a major obstacle to effective treatment of intrinsic brain tumors. Invasion is directly related to histologic malignancy, but occurs to some extent irrespective of tumor grade. Because the brain-to-tumor interface is not well demarcated, total surgical removal is rarely possible; moreover, as invading cells transiently arrest from cell division they are refractory to radiotherapeutic intervention. Invading cells may also be protected from the action of cytotoxic drugs by the presence of an intact blood-brain barrier. The invading cells, having migrated several millimeters or even centimeters from the main focus of the tumor, return to cycle phase under the control of some as yet unknown microenvironmental cue to form a recurrent tumor adjacent to the original site of presentation. Recent cellular and genetic information concerning factors underlying invasion may not only yield suitable targets for adaptation of existing therapies, but may also lead to novel approaches in glioma management.

Molecular classification of cutaneous malignant melanoma by gene expression profiling.

The most common human cancers are malignant neoplasms of the skin. Incidence of cutaneous melanoma is rising especially steeply, with minimal progress in non-surgical treatment of advanced disease. Despite significant effort to identify independent predictors of melanoma outcome, no accepted histopathological, molecular or immunohistochemical marker defines subsets of this neoplasm. Accordingly, though melanoma is thought to present with different 'taxonomic' forms, these are considered part of a continuous spectrum rather than discrete entities. Here we report the discovery of a subset of melanomas identified by mathematical analysis of gene expression in a series of samples. Remarkably, many genes underlying the classification of this subset are differentially regulated in invasive melanomas that form primitive tubular networks in vitro, a feature of some highly aggressive metastatic melanomas. Global transcript analysis can identify unrecognized subtypes of cutaneous melanoma and predict experimentally verifiable phenotypic characteristics that may be of importance to disease progression.

Characterization of a canine glioma cell line as related to established experimental brain tumor models.

A large animal tumor model for anaplastic glioma has been recently developed using immunotolerant allogeneic Beagle dogs and an established canine glioma cell line, J3T. This model offers advantages in terms of tumor morphology and similarity to human anaplastic glioma. The present study was aimed at evaluating the biological characteristics of the J3T canine glioma cell line as related to experimental gene therapy studies. Furthermore, development and morphology of canine brain tumors in a xenogeneic immunodeficient SCID mouse model was investigated. It was demonstrated that cultured J3T cells can be efficiently infected by adenovirus (AV), herpes-simplex type I (HSV), or retrovirus (RV) vectors, as well as by non-virus vectors such as cationic liposome/DNA complexes. Thus, in terms of infectability and transfectability, J3T cells seem to be closer to human glioma than the 9L rodent gliosarcoma. Cytotoxicity of selection antibiotics such as G418, puromycin, and hygromycin on J3T cells essentially resemble cytotoxicity seen with other established glioma lines, for example, 9L, U87, or U343. RV-mediated HSV-TK/GCV gene therapy demonstrated comparable LD50 for TK-expressing and control (non-expressing) J3T and 9L cells treated with Ganciclovir. Further, it was proven that J3T cells are tumorigenic and may grow heterotopically and orthotopically in a xenogeneic immunodeficient host, the SCID mouse, although morphology and growth pattern of these xenogeneic tumors differ from the demonstrated invasive phenotype in the Beagle dog.

Gap junction intercellular communication in gliomas is inversely related to cell motility.

Gliomas are lethal because of local invasion into brain parenchyma. Glioma cells were isolated from different regions (white matter, gray matter and tumor core) of a glioma-bearing dog brain. Individual clonal cell lines were established from each area, and characterized for growth, migration and gap junctions. The regional clonal cell lines differed in rates and preferred substrate for migration. Cell lines generated from invaded white matter showed stimulated migration on collagen and variable migration on merosin, whereas migration of cell lines derived from invaded gray matter showed the reciprocal responses: stimulation on merosin and inhibition on collagen. Gap junctional communication showed significant degrees of variation between the different clones. A direct inverse relationship between the number of cells demonstrating gap junctional communication and migration rate of cells away from multicellular spheroids was evident. Glioma cells which have a reduced capacity to connect to each other have an accelerated migration rate onto autologous, glioma-derived matrix. These results suggest that invasive glioma cells suppress autologous cell-to-cell cohesion, partly evident as reduced formation of gap junctions. In addition, glioma cells were stimulated to migrate in a dose-dependant manner in response to epidermal growth factor (EGF) coincident with the reduction of Cx43 levels and increased serine phosphorylation. We speculate that in order for glioma cells to invade locally into brain parenchyma they must first detach from neighboring cells ("let go...let's go" paradigm of invasion).

Allogeneic astrocytoma in immune competent dogs.

We have induced in canines long-term immune tolerance to an allogeneic cell line derived from a spontaneous canine astrocytoma. Allogeneic astrocytoma cells were implanted endoscopically into the subcutaneous space of fetal dogs before the onset of immune competency (< 40th gestational day). At adulthood, dogs rendered tolerant successfully serve as recipients of intracranial transplants of their growing allogeneic, subcutaneous tumor. Transplanted dogs subsequently develop a solid brain tumor with histological features similar to the original astrocytoma. This model may allow rapid development and evaluation of new therapies for brain tumors, as well as afford tumor biology studies that are untenable in smaller, immune incompetent, or inbred animals harboring less representative tumors.

"...those left behind." Biology and oncology of invasive glioma cells.

Although significant technical advances in surgical and radiation treatment for brain tumors have emerged in recent years, their impact on clinical outcome for patients has been disappointing. A fundamental source of the management challenge presented by glioma patients is the insidious propensity of the malignant cells to invade into adjacent normal brain. Invasive tumor cells escape surgical removal and geographically dodge lethal radiation exposure. Recent improved understanding of the biochemistry and molecular determinants of glioma cell invasion provide valuable insight to the underlying biological features of the disease, as well as illuminating possible new therapeutic targets. Heightened commitment to migrate and invade is accompanied by a glioma cell's reduced proliferative activity. The microenvironmental manipulations coincident to invasion and migration may also impact the glioma cell's response to cytotoxic treatments. These collateral aspects of the glioma cell invasive phenotype should be further explored and exploited as novel antiglioma therapies.

Thromboxane synthase regulates the migratory phenotype of human glioma cells.

The capacity of glial tumor cells to migrate and diffusely infiltrate normal brain compromises surgical eradication of the disease. Identification of genes associated with invasion may offer novel strategies for anti-invasive therapies. The gene for TXsyn, an enzyme of the arachidonic acid pathway, has been identified by differential mRNA display as being overexpressed in a glioma cell line selected for migration. In this study TXsyn mRNA expression was found in a large panel of glioma cell lines but not in a strain of human astrocytes. Immunohistochemistry demonstrated TXsyn in the parenchyma of glial tumors and in reactive astrocytes, whereas it could not be detected in quiescent astrocytes and oligodendroglia of normal brain. Glioma cell lines showed a wide range of thromboxane B2 formation, the relative expression of which correlated with migration rates of these cells. Migration was effectively blocked by specific inhibitors of TXsyn, such as furegrelate and dazmegrel. Other TXsyn inhibitors and cyclooxygenase inhibitors were less effective. Treatment with specific inhibitors also resulted in a decrease of intercellular adhesion in glioma cells. These data indicate that TXsyn plays a crucial role in the signal transduction of migration in glial tumors and may offer a novel strategy for anti-invasive therapies.