Aetiology of cerebrospinal fluid rhinorrhoea in a Dutch retrospective cohort from two tertiary referral centres.

BACKGROUND: Cerebrospinal fluid (CSF) rhinorrhoea has different aetiologies, with spontaneous leaks related to female gender and obesity. Limited data is available on patient characteristics and surgical outcomes across different aetiologies of CSF leaks in relatively non-obese populations. METHODS: Retrospective cohort study from two tertiary referral centres including adult patients that underwent surgical closure of a CSF leak, divided into four aetiologies: traumatic, iatrogenic, secondary to structural intracranial pathology (SIP), and spontaneous. Data included patient characteristics, presenting symptoms, preoperative radiologic findings, intracranial pressure (ICP) and surgical outcomes. RESULTS: 72 patients were included: 9 traumatic, 15 iatrogenic, 4 SIP and 44 spontaneous leaks. Primary surgical success was 79%, rising to 93% with reinterventions. Spontaneous leak cases displayed highest female proportion and BMI. A meningo(-encephalo)cele was present in 33 patients and was associated with surgical failure and previous meningitis. No significant differences were observed between different aetiologies regarding patient characteristics, presenting symptoms, or surgical success rates. CONCLUSIONS: Even in a relatively non-obese population, the majority of CSF leaks is spontaneous and associated with female gender and obesity. Otherwise, no differences exist across aetiologies regarding patient characteristics, presenting symptoms or surgical success.

Low-noise φ-OTDR employing nonlinear optical preamplification for distributed acoustic sensing.

A phase sensitive optical time domain reflectometry sensing scheme employing a two-stage nonlinear optical preamplification system is proposed to reduce the blind spot effect in Rayleigh scattering by improving the optical power distribution and to enhance the resolution at locations of low-backscatter intensity measurements, providing a higher signal-to-noise ratio for distributed acoustic measurements; the developed system has been tested in-laboratory and on in-field monitoring of a survey well in Cottessen, The Netherlands. The characterization shows strain noise levels below 1 nɛ for a 10 kHz sampling rate.

NWChem: Past, present, and future.

Specialized computational chemistry packages have permanently reshaped the landscape of chemical and materials science by providing tools to support and guide experimental efforts and for the prediction of atomistic and electronic properties. In this regard, electronic structure packages have played a special role by using first-principle-driven methodologies to model complex chemical and materials processes. Over the past few decades, the rapid development of computing technologies and the tremendous increase in computational power have offered a unique chance to study complex transformations using sophisticated and predictive many-body techniques that describe correlated behavior of electrons in molecular and condensed phase systems at different levels of theory. In enabling these simulations, novel parallel algorithms have been able to take advantage of computational resources to address the polynomial scaling of electronic structure methods. In this paper, we briefly review the NWChem computational chemistry suite, including its history, design principles, parallel tools, current capabilities, outreach, and outlook.

Guidelines on the benefit-risk assessment of the presence of phthalates in certain medical devices covering phthalates which are carcinogenic, mutagenic, toxic to reproduction (CMR) or have endocrine-disrupting (ED) properties.

By the new Medical Device Regulation (MDR, EU 2017/745) the use of certain phthalates which are carcinogenic, mutagenic, toxic to reproduction (CMR) or have endocrine-disrupting (ED) properties, above 0.1% by weight (w/w) is only allowed after a proper justification. The SCHEER provide Guidelines on the benefit-risk assessment (BRA) of the presence of such phthalates in certain medical devices. The Guidelines describe the methodology on how to perform a BRA for the justification of the presence of CMR/ED phthalates in medical devices and/or or parts or materials used therein at percentages above 0.1% w/w. They also describe the evaluation of possible alternatives for these phthalates used in medical devices, including alternative materials, designs or medical treatments. Relevant stakeholders e.g. manufacturers, notified bodies and regulatory bodies, can use the guidelines. The approach of these guidelines may also be used for a BRA of other CMR/ED substances present in medical devices. SCHEER noticed that a number of BRA methodologies are theoretically available. However, there is a considerable lack of data needed for the BRA for potential relevant alternatives to be used in medical devices. Therefore, SCHEER encourages manufacturers to generate data of high quality on such alternatives for CMR/ED phthalates in medical devices.

Out-of-hospital cardiac arrest: the prospect of E-CPR in the Maastricht region.

AIM: The current outcome of out-of-hospital cardiac arrest (OHCA) patients in the Maastricht region was analysed with the prospect of implementing extracorporeal cardiopulmonary resuscitation (E-CPR). METHODS: A retrospective analysis of adult patients who were resuscitated for OHCA during a 24-month period was performed. RESULTS: 195 patients (age 66 [57-75] years, 82 % male) were resuscitated for OHCA by the emergency medical services and survived to admission at the emergency department. Survival to hospital discharge was 46.2 %. Notable differences between non-survivors and survivors were observed and included: age (70 [58-79] years) vs. (63 [55-72] years, p = 0.01), chronic heart failure (18 vs. 7 %, p = 0.02), shockable rhythm (67 vs. 99 %, p < 0.01), and return of spontaneous circulation (ROSC) at departure from the site of the arrest (46 vs. 99 %, p < 0.01) and on arrival to the emergency department (43 vs. 98 %, p < 0.01), respectively. Acute coronary syndrome was diagnosed in 32 % of non-survivors vs. 59 % among survivors, p < 0.01. Therapeutic hypothermia was provided in non-survivors (20 %) vs. survivors (43 %), p < 0.01. Percutaneous coronary intervention (PCI) was performed in 14 % of non-survivors while 52 % of survivors received PCI (p < 0.01). No statistical significance was observed in terms of gender, witnessed arrest, bystander CPR, or automated external defibrillator deployed among the cohort. At hospital discharge, moderately severe neurological disability was present in six survivors. CONCLUSION: These observations are compatible with the notion that a shockable rhythm, ROSC, and post-arrest care improve survival outcome. Potentially, initiating E-CPR in the resuscitation phase in patients with a shockable rhythm and no ROSC might serve as a bridge to definite treatment and improve survival outcome.

The role of masticatory muscles in the continuous loading of the mandible.

Muscles are considered to play an important role in the ongoing daily loading of bone, especially in the masticatory apparatus. Currently, there are no measurements describing this role over longer periods of time. We made simultaneous and wireless in vivo recordings of habitual strains of the rabbit mandible and masseter muscle and digastric muscle activity up to ∼25 h. The extent to which habitually occurring bone strains were related to muscle-activity bursts in time and in amplitude is described. The data reveal the masseter muscle to load the mandible almost continuously throughout the day, either within cyclic activity bouts or with thousands of isolated muscle bursts. Mandibular strain events rarely took place without simultaneous masseter activity, whereas the digastric muscle only played a small role in loading the mandible. The average intensity of masseter-muscle activity bouts was strongly linked to the average amplitude of the concomitant bone-strain events. However, individual pairs of muscle bursts and strain events showed no relation in amplitude within cyclic loading bouts. Larger bone-strain events, presumably related to larger muscle-activity levels, had more constant principal-strain directions. Finally, muscle-to-bone force transmissions were detected to take place at frequencies up to 15 Hz. We conclude that in the ongoing habitual loading of the rabbit mandible, the masseter muscle plays an almost non-stop role. In addition, our results support the possibility that muscle activity is a source of low-amplitude, high-frequency bone loading.

Variations in habitual bone strains in vivo: long bone versus mandible.

Little is known about the similarities and dissimilarities between daily in vivo strain histories of different bones, other than the generally accepted view that most bones need daily loading to maintain their mass. Similarities in daily strain histories might uncover a common basic mechanical stimulus for homeostatic bone maintenance, whereas dissimilarities might explain why bones respond differently to changes in their environment. We compared the daily strain histories of two different bones from the rabbit: the tibiofibula and the mandible. Bone strain was recorded wirelessly in freely moving animals up to 57 h. Habitual strain amplitudes, rates, and frequencies were compared. The exponential decrease in occurrence of greater strain amplitudes was similar in long and mandibular bone. Also similar was the exponentially decreasing incidence of higher strain rates. Mandibular-bone strains distinguished themselves from long-bone strains, however, through the presence of a plateau in the occurrence of compressive strains with amplitudes between 200 and 450 microstrain (µÎµ) and in the occurrence of compressive-strain rates between 5000 and 10,000 µÎµ/s. The frequency spectrum of the mandibular-bone strain history contained peaks at 4.4 Hz and 8.9 Hz, which were absent in the long-bone strain spectrum. We hypothesise that the exponentially decreasing incidence of larger strain amplitudes and rates might outline the minimum amount of mechanical stimuli needed for bone maintenance. Furthermore, the strong presence of rhythmicity in mandibular strains might provide an important clue in confirming or improving the anabolic character of cyclic-loading regimes employed in clinical settings.

A novel method to generate unmarked gene deletions in the intracellular pathogen Rhodococcus equi using 5-fluorocytosine conditional lethality.

A novel method to efficiently generate unmarked in-frame gene deletions in Rhodococcus equi was developed, exploiting the cytotoxic effect of 5-fluorocytosine (5-FC) by the action of cytosine deaminase (CD) and uracil phosphoribosyltransferase (UPRT) enzymes. The opportunistic, intracellular pathogen R. equi is resistant to high concentrations of 5-FC. Introduction of Escherichia coli genes encoding CD and UPRT conferred conditional lethality to R. equi cells incubated with 5-FC. To exemplify the use of the codA::upp cassette as counter-selectable marker, an unmarked in-frame gene deletion mutant of R. equi was constructed. The supA and supB genes, part of a putative cholesterol catabolic gene cluster, were efficiently deleted from the R. equi wild-type genome. Phenotypic analysis of the generated DeltasupAB mutant confirmed that supAB are essential for growth of R. equi on cholesterol. Macrophage survival assays revealed that the DeltasupAB mutant is able to survive and proliferate in macrophages comparable to wild type. Thus, cholesterol metabolism does not appear to be essential for macrophage survival of R. equi. The CD-UPRT based 5-FC counter-selection may become a useful asset in the generation of unmarked in-frame gene deletions in other actinobacteria as well, as actinobacteria generally appear to be 5-FC resistant and 5-FU sensitive.

Association of vitamin B12, methylmalonic acid, and functional parameters.

INTRODUCTION: Diagnosis of vitamin B12 deficiency is difficult, as there is no conclusive single test for this disorder. We evaluated the association of serum B12 and methylmalonic acid (MMA) with haematologic parameters and physical and cognitive functioning in an effort to use such clinical parameters to improve the interpretation of serum values. METHODS: We used data of participants > 19 years of age from NHANES 2011-2012 and 2013-2014, a cross-sectional survey in the United States. Functional status was assessed with questionnaires on current health condition, disability, hospital utilisation, cognitive functioning, mental health and depression, and physical functioning. Muscle strength assessed with a handgrip dynamometer was used as a performance parameter. Results were evaluated both for the entire population and participants of Western European descent. Because renal function influences MMA concentrations and is a proxy for both frailty and comorbidity, all results were additionally stratified for individuals with normal vs impaired renal function (eGFR < 60 ml/min). RESULTS: In total, data of 9645 participants (mean age 49 (SD 17) years, 49.3% males) were included. Out of all participants with serum B12 < 140, 140-300, and 301-1000 pmol/l, 56.2%, 13.5%, and 4.1%, respectively had elevated MMA. MMA concentrations were more strongly associated with poor functional status and physical performance than serum B12. We identified a significant and independent association of MMA concentrations, as well as haemoglobin and co-morbidity with muscle strength. CONCLUSIONS/INTERPRETATIONS: A large proportion of individuals with a decreased serum B12 concentration still has normal MMA concentrations. Elevated MMA concentrations were more strongly associated with poor functional performance than serum B12.

Heat shock response of the rat lens.

The sequence relationship between the small heat shock proteins and the eye lens protein alpha-crystallin (Ingolia, T. D., and E. E. Craig, 1982, Proc. Natl. Acad. Sci. USA, 79: 2360-2364) prompted us to subject rat lenses in organ culture to heat shock and other forms of stress. The effects on protein synthesis were followed by labeling with [35S]methionine and analysis by one- and two-dimensional gel electrophoresis and fluorography. Heat shock gave a pronounced induction of a protein that could be characterized as the stress protein SP71. This protein probably corresponds to the major mammalian heat shock protein hsp70. Also two minor proteins of 16 and 85 kD were induced, while the synthesis of a constitutive heat shock-related protein, P73, was considerably increased. The synthesis of SP71 started between 30 and 60 min after heat shock, reached its highest level after 3 h, and had stopped again after 8 h. In rat lenses that were preconditioned by an initial mild heat shock, a subsequent shock did not cause renewed synthesis of SP71. This effect resembles the thermotolerance phenomenon observed in cultured cells. The proline analogue azetidine-2-carboxylic acid, zinc chloride, ethanol, and calcium chloride did not, under the conditions used, induce stress proteins in the rat lens. Sodium arsenite, however, had very much the same effects as heat shock. Calcium ionophore A23187 specifically and effectively induced the synthesis of the glucose-regulated protein GRP78. No special response to stress on crystallin synthesis was noticed.

Tau-crystallin/alpha-enolase: one gene encodes both an enzyme and a lens structural protein.

tau-Crystallin has been a major component of the cellular lenses of species throughout vertebrate evolution, from lamprey to birds. Immunofluorescence analysis of the embryonic turtle lens, using antiserum to lamprey tau-crystallin showed that the protein is expressed throughout embryogenesis and is present at high concentrations in all parts of the lens. Partial peptide sequence for the isolated turtle protein and deduced sequences for several lamprey peptides all revealed a close similarity to the glycolytic enzyme enolase (E.C. 4.2.1.11). A full-sized cDNA for putative duck tau-crystallin was obtained and sequenced, confirming the close relationship with alpha-enolase. Southern blot analysis showed that the duck genome contains a single alpha-enolase gene, while Northern blot analysis showed that the message for tau-crystallin/alpha-enolase is present in embryonic duck lens at 25 times the abundance found in liver. tau-Crystallin possesses enolase activity, but the activity is greatly reduced, probably because of age-related posttranslational modification. It thus appears that a highly conserved, important glycolytic enzyme has been used as a structural component of lens since the start of vertebrate evolution. Apparently the enzyme has not been recruited for its catalytic activity but for some distinct structural property. tau-Crystallin/alpha-enolase is an example of a multifunctional protein playing two very different roles in evolution but encoded by a single gene.

Resolution of the early placental mammal radiation using Bayesian phylogenetics.

Molecular phylogenetic studies have resolved placental mammals into four major groups, but have not established the full hierarchy of interordinal relationships, including the position of the root. The latter is critical for understanding the early biogeographic history of placentals. We investigated placental phylogeny using Bayesian and maximum-likelihood methods and a 16.4-kilobase molecular data set. Interordinal relationships are almost entirely resolved. The basal split is between Afrotheria and other placentals, at about 103 million years, and may be accounted for by the separation of South America and Africa in the Cretaceous. Crown-group Eutheria may have their most recent common ancestry in the Southern Hemisphere (Gondwana).

Evolution of eye lens crystallins: the stress connection.

Crystallins, the structural proteins of the eye lens, ensure the transparency and integrity of the lens throughout life. Recent sequence comparisons have shown that evolution has recruited crystallins among already existing heat-shock proteins and stress-inducible enzymes.

Exceptional response of brain metastases to short course nivolumab while on high-dose steroids.

In this manuscript, we describe a patient with an exceptional response of brain metastases from lung cancer to short course nivolumab while on high-dose steroids. This case shows that immunotherapy can cause delayed and enduring responses even in patients with poor predictive parameters for treatment success, such as low programmed death ligand-1 (PDL1) expression and long-term treatment with high-dose corticosteroids. Secondly, it underscores the importance of follow up after the administration of immunotherapy, even in cases with a deemed poor prognosis and few received cycles of immunotherapy.

Dutch healthcare professionals' opinion on vaccination and education to prevent infections in immunocompromised patients: A mixed-method study with recommendations for daily practice.

BACKGROUND: The fast-growing population of immunocompromised patients (ICP) is more vulnerable to infectious diseases, demanding strategies to protect them. These strategies seem inconsistent in available guidelines and in practices. We aim to evaluate healthcare professionals' (HCP) opinions on vaccination to reduce the number and severity of infections in ICP. METHODS: A mixed-method study, with an exploratory sequential design, was performed. Medical specialists from various departments in a tertiary care center in the Netherlands were invited for semi-structured interviews to explore their perspective on preventive care of ICP. Topics that play a substantial role in daily practice for ICP were translated into a survey to gain insight into what extent opinions were generalizable to Erasmus Medical Center. RESULTS: Surveys were completed by 689 HCP (43% of the invitees), 269 of them treated at least two ICP weekly on average and were considered eligible for further analysis. Quantitative data showed that according to 80 percent of HCP, preventive care for ICP can be improved. Education was chosen by 40 percent as the most important intervention to reduce the number and severity of infections. Vaccinations were valued as important by seventeen percent of HCP. Except for influenza, vaccinations were not regularly discussed during routine consultations. Difficulties to administer vaccinations were experienced by 75 percent of HCP. CONCLUSION: According to our respondents, education is the most promising intervention to reduce the number and severity of infections in ICP. To reach a higher vaccine uptake, we recommend HCP to address vaccinations more frequently during consultations and to search for solutions to alleviate barriers to vaccinate.

Pulmonary tumours in the Netherlands: focus on temporal trends in histology and stage and on rare tumours.

BACKGROUND: Recent temporal trends in histology and stage of pulmonary tumours in the Netherlands were studied. The incidence of rare pulmonary tumours was determined. METHODS: All tumours originating from the trachea, bronchus and lung recorded in the Netherlands Cancer Registry were included. Based on ICD-O morphology codes, five major subgroups were constructed: squamous carcinoma (SC), adenocarcinoma (AC), large cell (undifferentiated) carcinoma (LC), small cell lung cancer (SCLC) and other (including uncommon tumours). RESULTS: Between 1989 and 2003, 134,894 tumours were diagnosed. In men the age-adjusted incidence of SC and SCLC decreased, AC remained stable and LC increased. In women the incidence of all subgroups increased. Since 1996, a stage shift was observed with fewer patients in stage I and more patients in stage IV at diagnosis. This stage shift occurred equally in SC, AC and LC. In SC, fewer patients presented with stage IV disease than in AC and LC (25% vs 44% and 49% in 2003, respectively). The incidence of adenosquamous carcinoma decreased from 0.6 to 0.29/100 000 (p<0.001). The incidence of carcinoid tumours, sarcomatoid carcinomas and primary pulmonary sarcomas remained stable (0.44, 0.17 and 0.08/100 000, respectively). CONCLUSION: The incidence of smoking-related tumours decreased in men (especially SC and SCLC) and increased in women (all subgroups). More patients presented with stage IV disease. The incidence of non-smoking-related uncommon tumours remained constant.

Irinotecan and cisplatin with concurrent thoracic radiotherapy in a once-every-three-weeks schedule in patients with limited-disease small-cell lung cancer: a phase I study.

BACKGROUND: Irinotecan and cisplatin with concurrent radiotherapy is a powerful treatment combination for patients with limited-disease small-cell lung cancer (LD-SCLC). The objective was to determine the dose-limiting toxicity (DLT) and maximum-tolerated dose (MTD) of irinotecan and cisplatin with concurrent thoracic radiotherapy (TRT) as a once-every-three-weeks schedule. PATIENTS AND METHODS: Patients with LD-SCLC received a fixed-dose of irinotecan (340 mg) and cisplatin (135mg) at day 1 in cycles 1 and 4. During cycles 2 and 3, irinotecan and cisplatin were given in a dose-escalation schedule with concurrent TRT (once daily, total dose 45Gray). RESULTS: No DLT was observed at first two levels (irinotecan 100mg or 120 mg and cisplatin 100mg at day 1 of cycles 2 and 3). In the first five patients, four episodes of grade III diarrhoea/dehydration were observed at cycles 1 and 4. Therefore, from the sixth patient on, fixed-dose irinotecan at cycles 1 and 4 was reduced to 250 mg. At the subsequent level of irinotecan 140 mg and cisplatin 100mg in cycles 2 and 3, two DLTs (severe oesophagitis and late vertebral radiation toxicity) were observed in one patient. CONCLUSION: Irinotecan 140 mg and cisplatin 100mg with concurrent TRT was considered the MTD. Irinotecan and cisplatin in a once-every-three-weeks schedule is not recommended due to severe toxicity. Irinotecan may be more suited for intermittent weekly administration.

Polypharmacology Within the Full Kinome: a Machine Learning Approach.

Protein kinases generate nearly a thousand different protein products and regulate the majority of cellular pathways and signal transduction. It is therefore not surprising that the deregulation of kinases has been implicated in many disease states. In fact, kinase inhibitors are the largest class of new cancer therapies. Understanding polypharmacology within the full kinome, how drugs interact with many different kinases, would allow for the development of safer and more efficacious cancer therapies. A full understanding of these interactions is not experimentally feasible making highly accurate computational predictions extremely useful and important. This work aims at making a machine learning model useful for investigating the full kinome. We evaluate many feature sets for our model and get better performance over molecular docking with all of them. We demonstrate that you can achieve a nearly 60% increase in success rate at identifying binding compounds using our model over molecular docking scores.

Intradiscal delivery of celecoxib-loaded microspheres restores intervertebral disc integrity in a preclinical canine model.

Low back pain, related to degeneration of the intervertebral disc (IVD), affects millions of people worldwide. Clinical studies using oral cyclooxygenase-2 (COX-2) inhibitors have shown beneficial effects, although side-effects were reported. Therefore, intradiscal delivery of nonsteroidal anti-inflammatory drugs can be an alternative treatment strategy to halt degeneration and address IVD-related pain. In the present study, the controlled release and biologic potency of celecoxib, a selective COX-2 inhibitor, from polyesteramide microspheres was investigated in vitro. In addition, safety and efficacy of injection of celecoxib-loaded microspheres were evaluated in vivo in a canine IVD degeneration model. In vitro, a sustained release of celecoxib was noted for over 28 days resulting in sustained inhibition of inflammation, as indicated by decreased prostaglandin E2 (PGE2) production, and anti-catabolic effects in nucleus pulposus (NP) cells from degenerated IVDs on qPCR. In vivo, there was no evidence of adverse effects on computed tomography and magnetic resonance imaging or macroscopic evaluation of IVDs. Local and sustained delivery of celecoxib prevented progression of IVD degeneration corroborated by MRI, histology, and measurement of NP proteoglycan content. Furthermore, it seemed to harness inflammation as indicated by decreased PGE2 tissue levels and decreased neuronal growth factor immunopositivity, providing indirect evidence that local delivery of a COX-2 inhibitor could also address pain related to IVD degeneration. In conclusion, intradiscal controlled release of celecoxib from polyesteramide microspheres prevented progression of IVD degeneration both in vitro and in vivo. Follow-up studies are warranted to determine the clinical efficacy of celecoxib-loaded PEAMs in chronic back pain.

In vitro and in vivo (cyto)toxicity assays using PVC and LDPE as model materials.

The choice for a biomaterial is partly based on the outcome of (cyto)toxicity assays. The rationales behind the selection of certain parameters, such as cell lines, controls, and animals, were evaluated using a positive and a negative control, and one experimental sample designed to induce intermediate toxicity. Extraction and direct contact assays were performed using human epidermal keratinocytes and mouse fibroblasts and mouse epithelial cells. Cell survival was measured with the tetrazolium salt (MTT) reduction assay. In addition, local implantation studies were performed in mice and rats. The positive control induced a high degree of toxicity in all in vitro tests performed, indicating that the toxicity observed in the direct contact assay was due to in situ extraction of toxic components. In the direct contact assay the negative control tested on the mouse fibroblasts resulted in a significant reduction of cell survival. No decrease in cell survival was found using the experimental sample. Subcutaneous implantation studies in mice showed that the positive control material induced a severe degeneration in mice. However, in rats just minimal alterations were noted. The experimental material induced moderate responses only in mice. Our results indicate that the direct contact assay provides limited additional information on the cytotoxicity of materials if certain limitations are not taken into account. For the in vivo implantation assay mice were superior to rats in detecting local toxic responses.