245 research outputs found

    Hypoxia induces no change in cutaneous thresholds for warmth and cold sensation

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    Hypoxia can affect perception of temperature stimuli by impeding thermoregulation at a neural level. Whether this impact on the thermoregulatory response is solely due to affected thermoregulation is not clear, since reaction time may also be affected by hypoxia. Therefore, we studied the effect of hypoxia on thermal perception thresholds for warmth and cold. Thermal perception thresholds were determined in 11 healthy overweight adult males using two methods for small nerve fibre functioning: a reaction-time inclusive method of limits (MLI) and a reaction time exclusive method of levels (MLE). The subjects were measured under normoxic and hypoxic conditions using a cross-over design. Before the thermal threshold tests under hypoxic conditions were conducted, the subjects were acclimatized by staying 14 days overnight (8 h) in a hypoxic tent system (Colorado Altitude Training: 4,000 m). For normoxic measurements the same subjects were not acclimatized, but were used to sleep in the same tent system. Measurements were performed in the early morning in the tent. Normoxic MLI cold sensation threshold decreased significantly from 30.3 ± 0.4 (mean ± SD) to 29.9 ± 0.7°C when exposed to hypoxia (P < 0.05). Similarly, mean normoxic MLI warm sensation threshold increased from 34.0 ± 0.9 to 34.5 ± 1.1°C (P < 0.05). MLE measured threshold for cutaneous cold sensation was 31.4 ± 0.4 and 31.2 ± 0.9°C under respectively normoxic and hypoxic conditions (P > 0.05). Neither was there a significant change in MLE warm threshold comparing normoxic (32.8 ± 0.9°C) with hypoxic condition (32.9 ± 1.0°C) (P > 0.05). Exposure to normobaric hypoxia induces slowing of neural activity in the sensor-to-effector pathway and does not affect cutaneous sensation threshold for either warmth or cold detection

    Aquaporin-4 and brain edema.

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    Aquaporin-4 (AQP4) is a water-channel protein expressed strongly in the brain, predominantly in astrocyte foot processes at the borders between the brain parenchyma and major fluid compartments, including cerebrospinal fluid (CSF) and blood. This distribution suggests that AQP4 controls water fluxes into and out of the brain parenchyma. Experiments using AQP4-null mice provide strong evidence for AQP4 involvement in cerebral water balance. AQP4-null mice are protected from cellular (cytotoxic) brain edema produced by water intoxication, brain ischemia, or meningitis. However, AQP4 deletion aggravates vasogenic (fluid leak) brain edema produced by tumor, cortical freeze, intraparenchymal fluid infusion, or brain abscess. In cytotoxic edema, AQP4 deletion slows the rate of water entry into brain, whereas in vasogenic edema, AQP4 deletion reduces the rate of water outflow from brain parenchyma. AQP4 deletion also worsens obstructive hydrocephalus. Recently, AQP4 was also found to play a major role in processes unrelated to brain edema, including astrocyte migration and neuronal excitability. These findings suggest that modulation of AQP4 expression or function may be beneficial in several cerebral disorders, including hyponatremic brain edema, hydrocephalus, stroke, tumor, infection, epilepsy, and traumatic brain injury

    Intake of α-linolenic acid and other fatty acids in relation to the risk of bladder cancer: results from the New Hampshire case–control study

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    The role of dietary fat in bladder cancer aetiology is currently unclear due to few studies, equivocal findings and a lack of information on important dietary fatty acids. The aim of the present study was to investigate the association between the intake of major dietary fats and fatty acids and the risk of bladder cancer. A case–control study was conducted in New Hampshire, USA. Dietary data were collected from 322 cases and 239 controls, and OR and 95 % CI were calculated using unconditional logistic regression. Adjustment was made for potential confounders: sex, age, smoking status, pack-years smoked, cholesterol and energy intake. Statistically significant reduced odds of bladder cancer were observed for high intakes (highest quartile v. lowest quartile) of α-linolenic acid (ALA) (OR 0.26, 95% CI 0.10, 0.65; P for trend=0.01) and vegetable fat (OR 0.39, 95% CI 0.18, 0.86; P for trend=0.03). Borderline statistically significant reduced odds were detected for polyunsaturated fat (OR 0.43, 95% CI 0.19, 0.98; P for trend=0.07) and linoleic acid (OR 0.43, 95% CI 0.19, 0.96; P for trend=0.06). These fats and fatty acids were highly correlated and following adjustment for each other, the only potential inverse association to remain was for ALA. The present findings suggest that ALA may have a protective role against developing bladder cancer; however, further investigation and replication in other epidemiological studies are required. Future research should focus on the type, source and quantities of different dietary fatty acids consumed

    Extraforaminal ligament attachments of the thoracic spinal nerves in humans

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    An anatomical study of the extraforaminal attachments of the thoracic spinal nerves was performed using human spinal columns. The objectives of the study are to identify and describe the existence of ligamentous structures at each thoracic level that attach spinal nerves to structures at the extraforaminal region. During the last 120 years, several mechanisms have been described to protect the spinal nerve against traction. All the described structures were located inside the spinal canal proximal to the intervertebral foramen. Ligaments with a comparable function just outside the intervertebral foramen are mentioned ephemerally. No studies are available about ligamentous attachments of thoracic spinal nerves to the spine. Five embalmed human thoracic spines (Th2–Th11) were dissected. Bilaterally, the extraforaminal region was dissected to describe and measure anatomical structures and their relationships with the thoracic spinal nerves. Histology was done at the sites of attachment of the ligaments to the nerves and along the ligaments. The thoracic spinal nerves are attached to the transverse process of the vertebrae cranial and caudal to the intervertebral foramen. The ligaments consist mainly of collagenous fibers. In conclusion, at the thoracic level, direct ligamentous connections exist between extraforaminal thoracic spinal nerves and nearby structures. They may serve as a protective mechanism against traction and compression of the nerves by positioning the nerve in the intervertebral foramen

    Offspring sex ratio and gonadal irradiation in the British Childhood Cancer Survivor Study

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    We investigated offspring sex ratio among 6232 offspring born to 3218 survivors of childhood cancer in relation to therapeutic irradiation, and pooled our data with those from two other large-scale studies giving a total of 9685 offspring. Exposure to high-dose gonadal irradiation was not associated with a significant alteration in offspring sex ratio compared to low doses (men: P=0.58, women: P=0.66). There was also no evidence that the ratio varied with time since cancer diagnosis when comparing survivors treated with radiotherapy vs those without (men: P=0.51; women: P=0.46). This, the largest study to date, finds no evidence that exposure to radiation affects the offspring sex ratio among survivors of childhood cancer

    Acute heart failure presentation, management, and outcomes in cancer patients: a national longitudinal study

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    AIMS: Currently, little evidence exists on survival and quality of care in cancer patients presenting with acute heart failure (HF). The aim of the study is to investigate the presentation and outcomes of hospital admission with acute HF in a national cohort of patients with prior cancer. METHODS AND RESULTS: This retrospective, population-based cohort study identified 221 953 patients admitted to a hospital in England for HF during 2012–2018 (12 867 with a breast, prostate, colorectal, or lung cancer diagnosis in the previous 10 years). We examined the impact of cancer on (i) HF presentation and in-hospital mortality, (ii) place of care, (iii) HF medication prescribing, and (iv) post-discharge survival, using propensity score weighting and model-based adjustment. Heart failure presentation was similar between cancer and non-cancer patients. A lower percentage of patients with prior cancer were cared for in a cardiology ward [−2.4% age point difference (ppd) (95% CI −3.3, −1.6)] or were prescribed angiotensin-converting enzyme inhibitors or angiotensin receptor antagonists (ACEi/ARB) for heart failure with reduced ejection fraction [−2.1 ppd (−3.3, −0.9)] than non-cancer patients. Survival after HF discharge was poor with median survival of 1.6 years in prior cancer and 2.6 years in non-cancer patients. Mortality in prior cancer patients was driven primarily by non-cancer causes (68% of post-discharge deaths). CONCLUSION: Survival in prior cancer patients presenting with acute HF was poor, with a significant proportion due to non-cancer causes of death. Despite this, cardiologists were less likely to manage cancer patients with HF. Cancer patients who develop HF were less likely to be prescribed guideline-based HF medications compared with non-cancer patients. This was particularly driven by patients with a poorer cancer prognosis

    The use of the SF-36 questionnaire in adult survivors of childhood cancer: evaluation of data quality, score reliability, and scaling assumptions

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    BACKGROUND: The SF-36 has been used in a number of previous studies that have investigated the health status of childhood cancer survivors, but it never has been evaluated regarding data quality, scaling assumptions, and reliability in this population. As health status among childhood cancer survivors is being increasingly investigated, it is important that the measurement instruments are reliable, validated and appropriate for use in this population. The aim of this paper was to determine whether the SF-36 questionnaire is a valid and reliable instrument in assessing self-perceived health status of adult survivors of childhood cancer. METHODS: We examined the SF-36 to see how it performed with respect to (1) data completeness, (2) distribution of the scale scores, (3) item-internal consistency, (4) item-discriminant validity, (5) internal consistency, and (6) scaling assumptions. For this investigation we used SF-36 data from a population-based study of 10,189 adult survivors of childhood cancer. RESULTS: Overall, missing values ranged per item from 0.5 to 2.9 percent. Ceiling effects were found to be highest in the role limitation-physical (76.7%) and role limitation-emotional (76.5%) scales. All correlations between items and their hypothesised scales exceeded the suggested standard of 0.40 for satisfactory item-consistency. Across all scales, the Cronbach's alpha coefficient of reliability was found to be higher than the suggested value of 0.70. Consistent across all cancer groups, the physical health related scale scores correlated strongly with the Physical Component Summary (PCS) scale scores and weakly with the Mental Component Summary (MCS) scale scores. Also, the mental health and role limitation-emotional scales correlated strongly with the MCS scale score and weakly with the PCS scale score. Moderate to strong correlations with both summary scores were found for the general health perception, energy/vitality, and social functioning scales. CONCLUSION: The findings presented in this paper provide support for the validity and reliability of the SF-36 when used in long-term survivors of childhood cancer. These findings should encourage other researchers and health care practitioners to use the SF-36 when assessing health status in this population, although it should be recognised that ceiling effects can occur

    Risk, risk factors and surveillance of subsequent malignant neoplasms in childhood cancer survivors: a review

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    Subsequent malignant neoplasms (SMNs) in childhood cancer survivors cause substantial morbidity and mortality. This review summarizes recent literature on SMN epidemiology, risk factors, surveillance, and interventions. Survivors of childhood cancer experience long-term increased SMN risk compared with the general population, with a greater than twofold increased solid tumor risk extending beyond age 40 years. There is a dose-dependent increased risk for solid tumors after radiotherapy, with the highest risks for tumors occurring in or near the treatment field (eg, greater than fivefold increased risk for breast, brain, thyroid, skin, bone, and soft tissue malignancies). Alkylating and anthracycline chemotherapies increase the risk for development of several solid malignancies in addition to acute leukemia/myelodysplasia, and these risks may be modified by other patient characteristics, such as age at exposure and, potentially, inherited genetic susceptibility. Strategies for identifying survivors at risk and initiating long-term surveillance have improved and interventions are underway to improve knowledge about late-treatment effects among survivors and caregivers. Better understanding of treatment-related risk factors and genetic susceptibility holds promise for refining surveillance strategies and, ultimately, upfront cancer therapies

    Late cardiac events after childhood cancer: Methodological aspects of the pan-european study pancaresurfup

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    Background and Aim Childhood cancer survivors are at high risk of long-Termadverse effects of cancer and its treatment, including cardiac events. The pan-European PanCareSurFup study determined the incidence and risk factors for cardiac events among childhood cancer survivors. The aim of this article is to describe the methodology of the cardiac cohort and nested case-control study within PanCareSurFup. Methods Eight data providers in Europe participating in PanCareSurFup identified and validated symptomatic cardiac events in their cohorts of childhood cancer survivors. Data onsymptomatic heart failure, ischemia, pericarditis, valvular disease and arrhythmia were collected and graded according to the Criteria for Adverse Events. Detailed treatment data, data on potential confounders, lifestyle related risk factors and general health problems were collected. Results The PanCareSurFup cardiac cohort consisted of 59,915 5-year childhood cancer survivors with malignancies diagnosed between 1940 and 2009 and classified according to the International Classification of Childhood Cancer 3. Different strategies were used to identify cardiac events such as record linkage to population/ hospital or regional based databases, and patient-And general practitioner-based questionnaires. Conclusion The cardiac study of the European collaborative research project PanCareSurFup will provide the largest cohort of 5-year childhood cancer survivors with systematically ascertained and validated data on symptomatic cardiac events. The result of this study can provide information to minimize the burden of cardiac events in childhood cancer survivors by tailoring the follow-up of childhood cancer survivors at high risk of cardiac adverse events, transferring this knowledge into evidence-based clinical practice guidelines and providing a platformfor future research studies in childhood cancer patients. © 2016 Feijen et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
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