1,179 research outputs found
A case study of anthropogenic impact on the CO2 levels in low-volume profile of the Balcarka Cave (Moravian Karst, Czech Republic)
Anthropogenic impact on CO2 levels was studied in the low-volume chamber connected with the low-profile corridor in Balcarka Cave, the show cave in Moravian Karst, during the period of limited ventilation. Modeling showed that the natural CO2 levels were controlled by the CO2 fluxes (up to ~ 3.14 × 10-2 mol s-1) from adjacent spaces. These fluxes changed with cave airflows and ventilation modes. Two main components of anthropogenic impact were recognized: (1) visitor breathing and (2) visitor movement. The CO2 input derived from individual visitor groups varied from 1.96 × 10-4 to 2.45 × 10-3 mol s-1, which was the significant part of the CO2 fluxes from adjacent spaces. The visitor movement induced the airflows up to 0.2 m3 s-1. They exceeded the natural airflows (up to 3.2 × 10-3 m3 s-1) by factor of more than 60. These airflows caused cave ventilation mode’s switching and, significant drop of CO2 fluxes/levels due to changed ventilation. The study therefore indicates that various anthropogenic influences in show cave can balance and neutralize each other, in dependence on cave morphology and seasonal conditions
The elusive renal cell carcinoma: reversal imaging of arterial phase to improve acuity
Risk Factors for Nonsynchronous Second Primary Malignancy and Related Death in Patients with Differentiated Thyroid Carcinoma
BACKGROUND: Differentiated thyroid cancer (DTC) survivors are at increased risk of developing nonsynchronous second primary malignancy (NSPM). This study aims to examine possible risk factors leading to occurrence of NSPM as well as risk factors leading to NSPM-related death in patients with DTC. METHODS: Of the 1,106 patients with DTC managed at our institution, 92 (8.3%) patients developed NSPM and 40 (3.6%) patients died of NSPM. All causes of death were confirmed by medical record, autopsy report or death certificate. Clinicopathological variables were compared between those without NSPM and with NSPM as well as between those who died of NSPM and did not die of NSPM. Significant variables on univariate analysis were entered into a Cox proportional hazards model. RESULTS: The median latency period from diagnosis of DTC to NSPM was 142.7 (range 16.8-511.0) months. For occurrence of NSPM, age at DTC diagnosis >/=50 years old [relative risk (RR) = 2.35], cumulative radioactive iodine (RAI) activity 3.0-8.9 GBq (RR = 2.38), and external local radiotherapy (ERT) (RR = 1.95) were significant risk factors. For NSPM-related death, age at DTC diagnosis >/=50 years old (RR = 3.32) and nonbreast cancer (RR = 5.76) were significant risk factors. CONCLUSIONS: NSPM accounted for 18.7% of all deaths in DTC, but mortality was high (43.5%). Age at DTC diagnosis >/=50 years old, cumulative RAI activity 3.0-8.9 GBq, and ERT were significant risk factors for occurrence of NSPM, whereas age at DTC diagnosis >/=50 years old and the diagnosis of nonbreast cancer were significant risk factors for NSPM-related death.published_or_final_versionSpringer Open Choice, 21 Feb 201
Coliform pyosalpinx as a rare complication of appendicectomy: a case report and review of the literature on best practice
<p>Abstract</p> <p>Introduction</p> <p>Coliform pyosalpinx is a rare entity. We report a case that occurred three months after appendicectomy for gangrenous appendicitis. There follows a literature review on best practice for the treatment of pyosalpinx.</p> <p>Case presentation</p> <p>A seventeen year old girl presented with an acute abdomen three months after an appendicectomy for gangrenous appendicitis. Intraoperative findings were bilateral pyosalpinx treated by aspiration, saline and Betadine irrigation and intravenous antibiotics.</p> <p>Conclusion</p> <p>Microbiological analysis of the pus revealed <it>Escherichia coli </it>and anaerobes. Chlamydia and Candida were not isolated. This is the first known reported case of Coliform Pyosalpinx following appendicectomy. The best treatment does not necessarily involve salpingectomy especially in women of reproductive age where fertility may become compromised.</p
Imaging-guided chest biopsies: techniques and clinical results
Background
This article aims to comprehensively describe indications, contraindications, technical aspects, diagnostic accuracy and complications of percutaneous lung biopsy.
Methods
Imaging-guided biopsy currently represents one of the predominant methods for obtaining tissue specimens in patients with lung nodules; in many cases treatment protocols are based on histological information; thus, biopsy is frequently performed, when technically feasible, or in case other techniques (such as bronchoscopy with lavage) are inconclusive.
Results
Although a coaxial system is suitable in any case, two categories of needles can be used: fine-needle aspiration biopsy (FNAB) and core-needle biopsy (CNB), with the latter demonstrated to have a slightly higher overall sensitivity, specificity and accuracy.
Conclusion
Percutaneous lung biopsy is a safe procedure even though a few complications are possible: pneumothorax, pulmonary haemorrhage and haemoptysis are common complications, while air embolism and seeding are rare, but potentially fatal complications
Phosphorylation and Activation of the Plasma Membrane Na+/H+ Exchanger (NHE1) during Osmotic Cell Shrinkage
The Na+/H+ Exchanger isoform 1 (NHE1) is a highly versatile, broadly distributed and precisely controlled transport protein that mediates volume and pH regulation in most cell types. NHE1 phosphorylation contributes to Na+/H+ exchange activity in response to phorbol esters, growth factors or protein phosphatase inhibitors, but has not been observed during activation by osmotic cell shrinkage (OCS). We examined the role of NHE1 phosphorylation during activation by OCS, using an ideal model system, the Amphiuma tridactylum red blood cell (atRBC). Na+/H+ exchange in atRBCs is mediated by an NHE1 homolog (atNHE1) that is 79% identical to human NHE1 at the amino acid level. NHE1 activity in atRBCs is exceptionally robust in that transport activity can increase more than 2 orders of magnitude from rest to full activation. Michaelis-Menten transport kinetics indicates that either OCS or treatment with the phosphatase inhibitor calyculin-A (CLA) increase Na+ transport capacity without affecting transport affinity (Km = 44 mM) in atRBCs. CLA and OCS act non-additively to activate atNHE1, indicating convergent, phosphorylation-dependent signaling in atNHE1 activation. In situ 32P labeling and immunoprecipitation demonstrates that the net phosphorylation of atNHE1 is increased 4-fold during OCS coinciding with a more than 2-order increase in Na+ transport activity. This is the first reported evidence of increased NHE1 phosphorylation during OCS in any vertebrate cell type. Finally, liquid chromatography and mass spectrometry (LC-MS/MS) analysis of atNHE1 immunoprecipitated from atRBC membranes reveals 9 phosphorylated serine/threonine residues, suggesting that activation of atNHE1 involves multiple phosphorylation and/or dephosphorylation events
Electrocardiographic Criteria for Left Ventricular Hypertrophy in Children
Previous studies to determine the sensitivity of the electrocardiogram (ECG) for left ventricular hypertrophy (LVH) in children had their imperfections: they were not done on an unselected hospital population, several criteria used in adults were not applied to children, and obsolete limits of normal for the ECG parameters were used. Furthermore, left ventricular mass (LVM) was taken as the reference standard for LVH, with no regard for other clinical evidence. The study population consisted of 832 children from whom a 12-lead ECG and an M-mode echocardiogram were taken on the same day. The validity of the ECG criteria was judged on the basis of an abnormal LVM index, either alone or in combination with other clinical evidence. The ECG criteria were based on recently established age-dependent normal limits. At 95% specificity, the ECG criteria have low sensitivities (<25%) when an elevated LVM index is taken as the reference for LVH. When clinical evidence is also taken into account, the sensitivity improved considerably (<43%). Sensitivities could be further improved when ECG parameters were combined. The sensitivity of the pediatric ECG in detecting LVH is low but depends strongly on the definition of the reference used for validation
Modeling “psychosis” in vitro by inducing disordered neuronal network activity in cortical brain slices
# The Author(s) 2009. This article is published with open access at Springerlink.com Introduction Dysregulation of neuronal networks has been suggested to underlie the cognitive and perceptual abnor-malities observed schizophrenia. Discussions An in vitro model of psychosis is proposed based on the two different approaches to cause aberrant networ
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