G tolerance and the vasoconstrictor reserve

Purpose

Because leg arterial stiffness is higher in subjects with high G tolerance, we hypothesized that subjects with high G tolerance would have larger capacity for vasoconstriction.

Methods

Sixteen subjects, eight with high and eight with low G tolerance (H and L group, respectively), were exposed to a cold pressor test (CPT) in supine and upright posture. Heart rate (HR), mean arterial pressure (MAP) and cardiac output (CO) were measured, and total peripheral resistance (TPR) and stroke volume (SV) were calculated.

Results

In the supine position, CPT increased TPR more in the H group; 31 ± 18 % than in the L group; 11 ± 7 % (p < 0.05). The L group had larger increases in CO than the H group; 17 ± 16 vs. 3.4 ± 7 % (p = 0.06). In the upright position, the H group had a larger MAP response to CPT than the L group; 26 ± 14 vs. 14 ± 7 % (p = 0.06). The H group, but not the L group, had significant increases in TPR whereas the L group had significant increases in CO and SV.

Conclusions

In response to CPT, the high G tolerance group elevated MAP by increasing TPR, whereas the low G tolerance group showed a dependency on increased CO. The H group seemed to have a larger vasoconstrictor reserve. The results further suggest that vasoconstrictor reserve capacity could constitute the link between the recent finding that indicates a relationship between G tolerance and arterial distensibility in the legs.     

In-Flight Transmission of a SARS-CoV-2 Lineage B.1.617.2 Harbouring the Rare S:E484Q Immune Escape Mutation

We describe a flight-associated infection scenario of seven individuals with a B.1.617.2 (Delta) lineage, harbouring an S:E484Q point mutation. In Sweden, at least 10% of all positive SARS-CoV-2 samples were sequenced in each county; the B.1.717.2 + S:E484Q combination was not detected in Sweden before and was imported within the scenario described in this report. The high transmission rate of the delta lineage combined with the S:E484Q mutation, associated with immune escape in other lineages, makes this specific genetic combination a possible threat to the global fight against the COVID-19 pandemic. Even within the Omicron wave, the B.1.617.2 + S:E484Q variant appeared in community samples in Sweden, as it seems that this combination has an evolutionary gain compared to other B.1.617.2 lineages. The here described genomic combination was not detectable with the common fasta file-based Pango-lineage analysis, hence increasing the probability of the true global prevalence to be higher.     

Total laryngopharyngectomy with circumferential reconstruction: Helsinki institutional study

European Archives of Oto-Rhino-Laryngology - Surgical complications after total laryngopharyngectomy (TLP) are common, reconstruction is challenging, and patients often lose their ability to...     

The brain-enriched microRNA miR-124 in plasma predicts neurological outcome after cardiac arrest

Introduction

Early prognostication after successful cardiopulmonary resuscitation is difficult, and there is a need for novel methods to estimate the extent of brain injury and predict outcome. In this study, we evaluated the impact of the cardiac arrest syndrome on the plasma levels of selected tissue-specific microRNAs (miRNAs) and assessed their ability to prognosticate death and neurological disability.

Methods

We included 65 patients treated with hypothermia after cardiac arrest in the study. Blood samples were obtained at 24 hours and at 48 hours. For miRNA-screening purposes, custom quantitative polymerase chain reaction (qPCR) panels were first used. Thereafter individual miRNAs were assessed at 48 hours with qPCR. miRNAs that successfully predicted prognosis at 48 hours were further analysed at 24 hours. Outcomes were measured according to the Cerebral Performance Category (CPC) score at 6 months after cardiac arrest and stratified into good (CPC score 1 or 2) or poor (CPC scores 3 to 5).

Results

At 48 hours, miR-146a, miR-122, miR-208b, miR-21, miR-9 and miR-128 did not differ between the good and poor neurological outcome groups. In contrast, miR-124 was significantly elevated in patients with poor outcomes compared with those with favourable outcomes (P < 0.0001) at 24 hours and 48 hours after cardiac arrest. Analysis of receiver operating characteristic curves at 24 and 48 hours after cardiac arrest showed areas under the curve of 0.87 (95% confidence interval (CI) = 0.79 to 0.96) and 0.89 (95% CI = 0.80 to 0.97), respectively.

Conclusions

The brain-enriched miRNA miR-124 is a promising novel biomarker for prediction of neurological prognosis following cardiac arrest.     

Primary endothelial sarcoma of the thoracic aorta

Primary malignant tumors of the aorta are extremely rare. The case of a 64-year-old woman who presented with peripheral embolism to both femoropopliteal arteries is reported. The search for a source revealed a polypoid lesion severely narrowing the lumen of the distal thoracic aorta. Differential diagnosis included thrombus and primary aortic tumor. Extirpation of the tumorous lesion was performed. Histologic examination revealed intimal aortic sarcoma of endothelial cell origin. Although the liver was the only site of suspected metastases at the time of operation, during the 18-month follow-up until the patient's death, generalized metastatic spread had developed. This case report thus demonstrates the generally poor prognosis of this rare variety of aortic sarcoma, in particular when symptoms have already occurred.     

Down regulation of TRPC1 by shRNA reduces mechanosensitivity in mouse dorsal root ganglion neurons in vitro

Mechanosensitivity is a crucial but poorly understood property of the sensory nervous system. Transient receptor potential (TRP) channels, which have been found to be responsible for the detection of other sensory stimuli such as temperature and pungent chemicals, have been suggested to also recognize stretch or pressure to cell membranes. TRPC1 is one candidate from studies in oocytes but evidence in native sensory neurons has been lacking. Therefore, we have measured an increase in intracellular Ca²⁺ levels upon mechanical activation of native mouse dorsal root ganglion (DRG) neurons in culture using hypoosmolar buffer. Our results show that down regulation of TRPC1 with short hairpin RNA results in a 65% reduction of neurons with stretch activated responses. These results implicate a direct or indirect involvement of TRPC1 in the mechanosensitivity of DRG neurons.     

Amygdala damage affects event‐related potentials for fearful faces at specific time windows

The amygdala is known to influence processing of threat‐related stimuli in distant brain regions, including visual cortex. The time‐course of these distant influences is unknown, although this information is important for resolving debates over likely pathways mediating an apparent rapidity in emotional processing. To address this, we recorded event‐related potentials (ERPs) to seen fearful face expressions, in preoperative patients with medial temporal lobe epilepsy who had varying degrees of amygdala pathology, plus healthy volunteers. We found that amygdala damage diminished ERPs for fearful versus neutral faces within the P1 time‐range, ∼100–150 ms, and for a later component at ∼500–600 ms. Individual severity of amygdala damage determined the magnitude of both these effects, consistent with a causal amygdala role. By contrast, amygdala damage did not affect explicit perception of fearful expressions nor a distinct emotional ERP effect at 150–250 ms. These results demonstrate two distinct time‐points at which the amygdala influences fear processing. The data also demonstrate that while not all aspects of expression processing are disrupted by amygdala damage, there is a crucial impact on an early P1 component. These findings are consistent with the existence of multiple processing stages or routes for fearful faces that vary in their dependence on amygdala function. Hum Brain Mapp, 2010. © 2009 Wiley‐Liss, Inc.     

Gaze-based assistive technology used in daily life by children with severe physical impairments – parents’ experiences

Objective: To describe and explore parents’ experiences when their children with severe physical impairments receive gaze-based assistive technology (gaze-based assistive technology (AT)) for use in daily life. Methods: Semi-structured interviews were conducted twice, with one year in between, with parents of eight children with cerebral palsy that used gaze-based AT in their daily activities. To understand the parents’ experiences, hermeneutical interpretations were used during data analysis. Results: The findings demonstrate that for parents, children’s gaze-based AT usage meant that children demonstrated agency, provided them with opportunities to show personality and competencies, and gave children possibilities to develop. Overall, children’s gaze-based AT provides hope for a better future for their children with severe physical impairments; a future in which the children can develop and gain influence in life. Conclusion: Gaze-based AT provides children with new opportunities to perform activities and take initiatives to communicate, giving parents hope about the children’s future.