Measuring nutrient fluxes across the sediment-water interface using benthic chambers

11 páginas, 8 figuras, 2 tablas.This paper presents a simple model to determine the benthic fluxes of matter across the sediment-water interface when a benthic chamber is used. The model is based on accepting that the limiting step for the overall rate of transfer while the chamber is in position is the diffusion through the diffusive boundary layer (DBL) overlying the sediment, and it assumes that this rate is necessarily affected by the procedure employed to measure the flux. Alteration of the benthic fluxes due to the action of macrofauna is included in the model and, operatively, is expressed in terms of a reduction in the thickness of the DBL between the sediment and the water. If the diffusive fluxes are determined simultaneously with the benthic chamber experiments, a value can be estimated for the thickness of the 'stagnant film'. Owing to the assumptions made and to the micro-heterogeneities of the sediment, this thickness can be considered to have both an operative and a statistical meaning, with respect to the entire surface area covered by the chamber. The values calculated in the Bay of Cádiz (SW Spain) vary between 0.36 and 0.71 mm, which are in agreement with measurements of this film made by different techniques in other littoral ecosystems. However, the values of the in situ fluxes estimated using this model and by other established procedures described in the literature can differ by more than 50%, for the same experiment, in strongly irrigated zones.The work was supported by the Consejo Superior de Investigaciones Científicas (CSIC) through research grant 630/070-1988.Peer reviewe

Myotonic dystrophy type 1 presenting with stroke-like episodes: a case report

BACKGROUND: It is well known that myotonic dystrophy type 1 (DM1) - Curschmann-Steinert disease - is associated with white matter lesions in the brain. Further, DM1 patients may suffer from cardiac involvement and cardioembolic strokes. We report on the unique case of an adult-onset DM1 without cardiac or vascular abnormalities presenting with stroke-like episodes. CASE PRESENTATION: A 40 y old white female was admitted twice to our stroke unit with apoplectic dizziness, nausea, headaches, and numbness in the right arm. She was suffering from type 2 diabetes, cataract, and endometriosis. Magnetic resonance imaging (MRI) revealed confluent white matter lesions in all cerebral lobes. There was no hyperintensity on diffusion-weighted imaging (DWI) and no gadolinium enhancement. Cerebrospinal fluid was normal. Surprisingly, myotonic discharges were detected in electromyography (EMG). Genetic testing revealed 200 ± 10 CTG repeats in the dystrophia myotonica protein kinase (DMPK) gene on chromosome 19 and DM1 was diagnosed. CONCLUSIONS: DM1 may be the cause of cerebral white matter lesions. This is the first case of DM1 presenting with stroke-like episodes

Music in disorders of consciousness

This review presents an overview of the use of music therapy in neurological early rehabilitation of patients with coma and other disorders of consciousness (DOC) such as unresponsive wakefulness syndrome (UWS) or minimally conscious state (MCS). There is evidence that patients suffering from UWS show emotional processing of auditory information, such as listening to speech. Thus, it seems reasonable to believe that music listening – as part of an enriched environment setting – may be of therapeutic value in these patients. There is, however, a considerable lack of evidence. The authors strongly encourage further studies to evaluate the efficacy of music listening in patients with DOC in neurological early rehabilitation. These studies should consider a precise clinical definition and homogeneity of the patient cohort with respect to the quality (coma vs. UWS vs. MCS), duration (rather weeks to months than days) and cause (traumatic vs. non-traumatic) of DOC, a standardised intervention protocol, valid clinical outcome parameters over a longer observation period (weeks to months), monitoring of neurophysiological and vegetative parameters and, if available, neuroimaging to confirm diagnosis and to demonstrate responses and functional changes in the patients` brains

Impact of Thyroid Hormone Levels on Functional Outcome in Neurological and Neurosurgical Early Rehabilitation Patients

Background. Neurological and neurosurgical early rehabilitation (NNER) is a specialized treatment option for patients with severe neurological disorders. The present study investigated whether thyroid hormone levels on admission have an impact on the outcome of NNER patients. Method. The study included 500 NNER patients who were admitted to the BDH-Clinic Hessisch Oldendorf between 2009 and 2010. Data such as age, sex, diagnoses, comorbidities, Glasgow Coma Scale score, length of stay, and thyroid hormone levels (obtained as part of clinical routine care) were analyzed retrospectively. Improvement in the Early Rehabilitation Barthel Index (ERBI) at the end of the NNER treatment was defined as outcome parameter. Results. Most patients made functional progress during treatment, as reflected in significant enhancements of the ERBI. Approximately half of the patients were transferred to further rehabilitation treatment. Young age, early onset of NNER treatment, low functional impairment on admission, and, in particular, low total T3 levels were independently associated with a good outcome. Conclusion. Age, severity of disease, and time between injury and admission are known to predict outcome. The present study confirms the influence of these general factors. In addition, an association between thyroid hormones and functional outcome was demonstrated for NNER patients

Prevalence of serum IgG antibodies against SARS-CoV-2 among clinic staff

The SARS-CoV-2 pandemic threatens health care providers and society. For planning of treatment capacities, it is of major importance to obtain reliable information on infection and fatality rates of the novel coronavirus. A German community study, the so-called Heinsberg study, found a 5-fold higher infection rate (and thus a remarkably lower fatality rate) than the officially reported cases suggest. We were interested to examine the SARS-CoV-2-IgG antibody status among clinic staff of a large neurological center in Northern Germany. Blood samples and questionnaires (demographic data, medical history) were collected pseudonymously. In total, 406 out of 525 (77.3%) of our employees participated in the study. The infection rate among the staff was as high as 2.7%. Including drop-outs (missing questionnaire but test result available), the infection rate was even higher (2.9%). Only 36% of the positively tested employees did suffer from flu-like symptoms in 2020. None of the nurses–having closest and longest contact to patients—were found to be positive. Despite the fact that the infection rate among clinic staff may not be directly compared to the situation in the surrounding county (due to different testing procedures), one might hypothesize that the infection rate could be more than 30-fold higher than the number of officially reported cases for the county of Hameln-Pyrmont. The high rate of IgG-positive, asymptomatic healthcare workers might help to overcome fears in daily work

Creatine kinase elevation caused by a combination of fluvastatin and telmisartan in a patient heterozygous for the CYP2C9*3 and ABCC2 -24C < T variants: a case report

BACKGROUND: Genetic factors as predictor of the individual outcome of drug therapy is one aim of personalized medicine approaches. CASE PRESENTATION: We report a drug metabolism based analysis of genetic polymorphisms in a Caucasian patient receiving fluvastatin and telmisartan experiencing myotoxicity (myalgia and moderate creatine kinase elevation). CONCLUSIONS: The obtained findings suggest that heterocygocity of cytochrome P450 CYP2C9*3 variant in combination with multidrug resistance-associated protein MRP2 -24C > T functions as risk factor predisposing to experience drug-drug interaction combing those drugs