首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 62 毫秒
1.
PurposeIn 2010, approximately 14.9 million babies (11.1%) were born preterm. Because preterm infants suffer from an immature thermoregulatory system they have difficulty maintaining their core body temperature at a constant level. Therefore, it is essential to maintain their temperature at, ideally, around 37 °C. For this, mathematical models can provide detailed insight into heat transfer processes and body-environment interactions for clinical applications.MethodsA new multi-node mathematical model of the thermoregulatory system of newborn infants is presented. It comprises seven compartments, one spherical and six cylindrical, which represent the head, thorax, abdomen, arms and legs, respectively. The model is customizable, i.e. it meets individual characteristics of the neonate (e.g. gestational age, postnatal age, weight and length) which play an important role in heat transfer mechanisms. The model was validated during thermal neutrality and in a transient thermal environment.ResultsDuring thermal neutrality the model accurately predicted skin and core temperatures. The difference in mean core temperature between measurements and simulations averaged 0.25±0.21 °C and that of skin temperature averaged 0.36±0.36 °C. During transient thermal conditions, our approach simulated the thermoregulatory dynamics/responses. Here, for all infants, the mean absolute error between core temperatures averaged 0.12±0.11 °C and that of skin temperatures hovered around 0.30 °C.ConclusionsThe mathematical model appears able to predict core and skin temperatures during thermal neutrality and in case of a transient thermal conditions.  相似文献   

2.
Background/AimTo evaluate whether non-closure of the visceral peritoneum after total abdominal hysterectomy (TAH) and bilateral salpingo-oophorectomy (BSO) in patients with uterine corpus carcinoma influences the volume of the small intestine within the irradiated volume during adjuvant radiotherapy or late radiation intestinal toxicity.Materials and methodsA total of 152 patients after TAH + BSO with adjuvant pelvic radiotherapy were studied. The state of peritonealization was retrospectively evaluated based on surgical protocols. The volume of irradiated bowels was calculated by CT-based delineation in a radiotherapy planning system. The influence of visceral peritonealization upon the volume of the small intestine within the irradiated volume and consequent late morbidity was analyzed.ResultsVisceral peritonealization was not performed in 70 (46%) of 152 studied patients. The state of peritonealization did not affect the volume of the irradiated small intestine (p = 0.14). Mean volume of bowels irradiated in patients with peritonealization was 488 cm3 (range 200–840 cm3, median 469 cm3); mean volume of bowels irradiated in patients without peritonealization was 456 cm3 (range 254–869 cm3, median 428 cm3). We did not prove any significant difference between both arms. Nor did we observe any influence of non-peritonealization upon late intestinal morbidity (p = 0.34).ConclusionNon-closure of the visceral peritoneum after hysterectomy for uterine corpus carcinoma does not increase the volume of the small intestine within the irradiated volume, with no consequent intestinal morbidity enhancement.  相似文献   

3.
AimIt is well known that inducing hyperthermia is a type of cancer treatment but some research groups indicate that this treatment is not effective. This article finds and explains the mechanism of this treatment and its possible problems.BackgroundHyperthermia is commonly known as a state when the temperature of the body rises to a level that can threaten one’s health. Hyperthermia is a type of cancer treatment in which body tissue is exposed to high temperatures (up to 45 °C). Research has shown that high temperatures can damage and kill cancer cells, usually with minimal injury to normal tissues. However, this mechanism is not known.Materials and MethodsWe recently treated cancer cells with different temperatures ranging from 37 °C to 47 °C and further measured their caspase 3 secretion by ELISA, western blot and cell survival rate by microscope.ResultsWe found that most cancer cells are able to resist hyperthermia more than normal cells most likely via non-activation of caspase3. We also found that hyperthermia-treated (≥41°) cancer cells extend a long pseudopod-like extension in comparison to the same cancer cells under normal conditions.ConclusionOur data here indicates that cancer cells have resistance to higher temperatures compared to normal cells via non-activation of caspase 3. This is a significant issue that needs to be brought to attention as the medical community has always believed that a high temperature treatment can selectively kill cancer/tumor cells. Additionally, we believe that the pseudopod-like extensions of hyperthermia-treated cancer cells must be related to its resistance to hyperthermia.  相似文献   

4.
AimTo ascertain whether patients with type 2 diabetes are screened for diabetic foot, and to analyze the factors related to patients and centers associated to performance of such screening.Material and methodsA multicenter, epidemiological, cross-sectional study was conducted. The clinical records of 443 patients with type 2 diabetes monitored at Primary Care for at least 12 months were reviewed. Demographic and healthcare variables and characteristics of the primary care center were recorded.ResultsIn the previous year, 51.2% of patients had been trained on foot self-care, 56.4% had undergone foot inspection, 39.5% had been examined with a monofilament, and palpation of peripheral pulses and measurement of the ankle-brachial index were performed in 45.8 and 10.1% of patients, respectively. Diabetic foot screening (inspection, monofilament testing, and palpation of peripheral pulses) was performed in 37% of study patients. Ulcer risk stratification was done in 12.4% of patients. A significant association was found between diabetic foot screening and presence of foot deformities (P < .001), history of neuropathy (P = .005), and history of peripheral artery disease (P < .05). Screening was also associated to some characteristics of the center, such as reception of information about goal achievement (P < .001) and economic incentives for goal attainment (P < .001).ConclusionsCompliance with diabetic foot screening and ulcer risk stratification in patients with type 2 diabetes in Primary Care was poor.  相似文献   

5.
Purpose of the studyThe influence of the stomatognathic apparatus on body posture is a continuously discussed topic with contrasting results. The aim of this study is to analyze differences in postural stability between subjects with and without myogenous TMD.Methods25 subjects affected by myogenous TMD according with DC/TMD (6 males, 19 females; mean age 31.75 ± 6.68 years) and a healthy control group of 19 subjects (4 Males, 15 Females; mean age 27.26 ± 3.85 years) were enrolled in the study.Both groups underwent a posturo-stabilometric force platform exam under different mandibular and visual conditions. Sway area and sway velocity of the COP (Center Of foot Pressure) posturo-stabilometric parameters were evaluated and compared applying Mann-U-Whitney statistical test.ResultsThe sway area and sway velocity parameters resulted statistically significantly higher in the TMD group (sway area p < 0.01; sway velocity p < 0.05) in mandibular maximum intercuspation and rest positions with eyes open.ConclusionsThis study demonstrates a significant difference in body postural stability between subjects with myogenous TMD and healthy controls. In particular, sway area and sway velocity postural parameters are increased in these subjects.  相似文献   

6.
ObjectivePatients with type 2 diabetes (T2DM) demonstrate low dietary adherence and this is further aggravated with comorbid obesity. The aim of the present study was to assess diet quality in patients with T2DM and comorbid obesity compared to patients with T2DM alone and to examine the associations between comorbidities and diet quality.MethodsThe sample consisted of 59 adult patients with diabesity (T2DM and comorbid obesity) and 94 patients with T2DM alone. All diabetes comorbidities and complications were recorded and diet quality was assessed with the Healthy Eating Index (HEI).ResultsMean raw HEI of the diabese subjects was 81.9 ± 7.1 and the diabetic subjects was 80.2 ± 6.9. When HEI was adjusted to the sex, age and weight status, the diabese demonstrated a higher HEI. Among comorbidities, only renal disease decreased HEI. According to the principal component analysis of the total sample, adequate diet quality was explained by cardiovascular disease, cigarette smoking, alcohol consumption, peptic ulcer, sex, diabesity and diabetic foot syndrome. In the diabese, adequate HEI was explained by diabetic foot syndrome, smoking, drinking alcohol and having a family history of diabetes.ConclusionsAdult patients with T2DM demonstrate adequate diet quality. Different factors are associated with the adoption of a high quality diet between the diabese and the T2DM alone.  相似文献   

7.
IntroductionTo validate the use of supine position and CT images for assessing abdominal circumference (AC).MethodA prospective study in consecutive patients undergoing scheduled abdominal CT at our center between 17 and 25 September 2012.AC was measured four times:
  • 1.Standing.
  • 2.While lying on the CT table.
  • 3.On CT images with a skin contour line, using OsiriX software.
  • 4.On CT images with an ellipse perimeter formula, using RAIM Alma 2010 software.
Measurements 1 and 2 were sequentially done by the same trained nurse before abdominal CT just above the iliac crest, while measurements 3 and 4 were done on the last abdominal CT slice not showing the iliac bone. Student's t tests and Q-Q and Bland–Altman plots were used for statistical analysis.ResultsA total of 102 patients were recruited. Mean age, 60 (35–78) years. Mean BMI, 25 (18–39) kg/m2. Mean AC, 93.2 (73–135) cm.No significant differences were found between the four ACs measured (Student's t test, P = 0.83).Q-Q and Bland–Altman plots showed good overlapping for the low and central values (73–110 cm) with a greater scatter for extremely high values.For the ellipse estimation, R2 was 0.987 with a mean error of 0.4 cm and a stretch dispersion between 1.1 and −0.3 cm.ConclusionSupine (either measured or estimated on CT images by free hand elliptical ROI or ellipse formula) and standing measurements appear to be equivalent for abdominal circumferences <110 cm.  相似文献   

8.
IntroductionPrevalence of hyperandrogenism (HA), including the polycystic ovary syndrome (PCOS), in female-to-male transsexuals (FMT) is high. This has been related to metabolic syndrome (MS), which appears to increase cardiovascular morbidity and mortality throughout cross-sex hormone (CSH) therapy.ObjectivesTo assess the prevalence of HA and PCOS in FMT patients before the start of CSH therapy, and their association to MS and its components, insulin resistance (IR) and other cardiovascular risk (CVR) factors.Materials and methodsSeventy-seven FMTs underwent clinical and biochemical assessment for HA before the start of CSH therapy. CVR, IR, and other MS parameters were also assessed.ResultsPrevalence of HA was 49.4% (73.7% were cases of PCOS [Rotterdam criteria]), and prevalence of PCOS in the overall sample was 36.4%. Prevalence of MS was 38.4% and 51.7% according to ATP-III and IDF criteria respectively). MS (according to ATP-III and IDF criteria respectively) was found in 36.8% and 57.9% as compared to 25.6% and 41% of patients with and without HA respectively (p < 0.0001 and P < 0.01 respectively). Of total patients, 54.5% had normal weight (body mass index [BMI] 18.5-24.9 kg.m-2), 26% were overweight (BMI 25-29.9 kg.m-2), and 19.5% were obese (BMI  30 kg.m-2). After adjusting for BMI, the comparison of hormonal, metabolic, and anthropometric parameters showed statistically significant differences in plasma glucose, HOMA-IR, and abdominal circumference (P < 0.001 for all), as well as HDL cholesterol (HDL) (P = 0.033), but not in total testosterone or calculated free testosterone levels. In the total sample, 27.3% had HDL levels less than 50 mg/dL.ConclusionsOverall HA, and PCOS in particular, are highly prevalent in FMTs. HA and PCOS are related to early development of SM, IR, and other CVR factors with unknown consequences in adulthood.  相似文献   

9.
《Endocrine practice》2008,14(8):993-999
ObjectiveTo evaluate the effect of exenatide therapy on cardiometabolic risk factors and anthropometric parameters in patients with metabolic syndrome.MethodsFrom June 2005 to June 2007, we performed a retrospective analysis of data extracted from the records of adult patients with metabolic syndrome being treated with exenatide. Diagnosis of any type of diabetes mellitus was exclusionary. Patients were initiated on exenatide therapy, 5 mcg, 1 hour before their morning and evening meals for the first month and were instructed to titrate up to 10 mcg. Cardiometabolic risk factors (total cholesterol, high-denssity lipoprotein cholesterol, triglycerides, calculated low- density lipoprotein cholesterol, and blood pressure) and anthropometric parameters (absolute body weight, body mass index, and abdominal girth) were measured at baseline and at 16 ± 4 weeks after initiating exenatide therapy. Data collected also included age, sex, metabolic syndrome diagnosis, and other concomitant medication used in the management of endocrine disorders.ResultsThe study population consisted of 299 patients (259 women, 40 men) with an age range of 18 to 74 years. Exenatide treatment was associated with significant reductions in mean body weight (P < .001) and body mass index (P < .001). Weight loss in 76.6% of patients was concomitant with a significant reduction in mean abdominal girth (P < .001). Further analysis revealed significant decreases in mean triglycerides (P < .001), total cholesterol (P < .01), and both systolic (P < .01) and diastolic blood pressure (P < .03). Approximately 60.2% of patients used metformin concomitantly, and half either decreased or discontinued metformin therapy.ConclusionsThis is the first report examining the effect of exenatide on patients with metabolic syndrome. We observed a significant improvement in cardiometabolic risk factors and anthropometric parameters as a result of exenatide over the treatment interval. (Endocr Pract. 2008;14:993-999)  相似文献   

10.
ObjectiveTo investigate possible alterations in cord blood levels of adipokine nesfatin-1 (secreted by adipose tissue and pancreatic β-cells and implicated in glucose metabolism and insulin resistance), as well as insulin, in large (LGA) and appropriate for gestational age (AGA) pregnancies, granted that these groups differ in body fat mass and metabolic/endocrine mechanisms.Materials and methodsCord blood nesfatin-1 and insulin concentrations were prospectively measured in 40 LGA (9 born from diabetic and 31 from non-diabetic mothers) and 20 AGA singleton full-term infants as well as their mothers.ResultsCord blood nesfatin-1 concentrations were significantly lower in LGA compared to AGA neonates (b = ?0.206, SE 0.07, p = 0.005). However, cord blood nesfatin-1 concentrations were elevated in infants born from mothers with gestational diabetes mellitus (GDM), compared to those born from non-diabetic mothers, after controlling for group (b = 0.190, SE 0.10, p = 0.05). Finally, cord blood nesfatin-1 concentrations were lower in cases of vaginal delivery (b = 0.11, SE 0.05, p = 0.042). Insulin levels were significantly elevated, as customized centiles increased (b = 0.004, SE = 0.002, p = 0.016). No significant correlation was found between insulin and nesfatin-1 in maternal and umbilical cord levels.ConclusionsIn this study nesfatin-1 levels are decreased in LGA compared to AGA fetuses. Fetal nesfatin-1 concentrations are higher in cases of GDM and cord blood nesfatin-1 concentrations are lower in cases of vaginal delivery.  相似文献   

11.
《Cancer epidemiology》2014,38(4):357-363
BackgroundEpidemiological studies on anthropometric features and cutaneous melanoma risk in women yielded inconsistent results, with few analyses involving prospective cohort data. Our objective was to explore several anthropometric characteristics in relation to the risk of melanoma in women.MethodsWe prospectively analysed data from E3N, a French cohort involving 98,995 women born in 1925–1950. Participants completed self-administered questionnaires sent biennially over 1990–2008. Relative risks (RRs) and 95% confidence intervals (CIs) were computed using Cox proportional hazards regression models, adjusted for age, number of naevi, freckling, skin and hair colour, skin sensitivity to sun exposure, residential sun exposure, and physical activity.ResultsHeight was positively associated with melanoma in age-adjusted models only (RR = 1.27, 95% CI = 1.05–1.55 for ≥164 cm vs. <160 cm; P for trend = 0.02). After full adjustment, there was a significantly positive relationship between sitting-to-standing height ratio and melanoma risk (RR = 1.40, 95% CI = 1.06–1.86 for ≥0.533 vs. <0.518; P for trend = 0.02). A large body shape at menarche was inversely associated with the risk of melanoma (RR = 0.78, 95% CI = 0.62–0.98; compared with lean). However, weight, body mass index, body surface area, waist or hip circumference, sitting height or leg length were not significantly associated with risk.ConclusionThese results suggest that height, sitting-to-standing height ratio and body shape at menarche may be associated with melanoma risk. Further research is required to confirm these relationships and better understand the underlying mechanisms.  相似文献   

12.
《Endocrine practice》2014,20(12):1309-1314
ObjectiveNeuroendocrine tumors (NETs) of the abdomen are rare tumors with an incidence of 3.56 per 100,000 in the general population. Obesity is a growing public health problem with varying effects on the severities of other diseases. We investigated the association between obesity and inpatient morbidity/mortality in patients with abdominal NETs utilizing the Nationwide Inpatient Sample (NIS).MethodsWe analyzed data from the NIS database to investigate the association between obesity and abdominal NETs using patient information from 22,096 patient discharges from January 1, 2009 to December 31, 2010.ResultsWe demonstrate that obesity is strongly associated with decreased rates of inpatient mortality in patients with NET (odds ratio [OR] = 0.6, multivariate P = .02) and that malnutrition is associated with a nearly 5-fold higher risk of inpatient mortality (multivariate P < .0005). We did not find a statistical interaction between obesity and malnutrition; however, patients who were both malnourished and obese had a lower mortality risk than purely malnourished patients.ConclusionsOur data suggests that nutritional status may be an important factor in inpatient mortality in patients with NETs, with obesity being protective. (Endocr Pract. 2014;20:1309-1314)  相似文献   

13.
ObjectiveTo determine any ethnic differences in circulating interleukin (IL)-6 concentrations among SAs and Europeans, and to assess their relationship with body composition and insulin resistance measures.MethodsBody composition was assessed among 80 SA and European men and women using anthropometry, dual-energy X-ray absorptiometry and abdominal CT scan. Oral glucose tolerance tests with insulin response were performed to assess insulin resistance measures. IL-6 levels were measured by high sensitivity ELISA.ResultsMedian IL-6 values were higher in SA compared with European women: 1.94 mg/l versus 1.51 mg/l, p = 0.041, but not so in men (1.56 mg/l versus 1.57 mg/l). Only measures of obesity, in particular percentage fat area (r = 0.6, p = 0.003), were positively correlated with IL-6 in SAs. Differences in body fat percentage (visceral and total) could explain up to 30% of the IL-6 difference between Asian and European women.ConclusionSA women have elevated circulating IL-6 levels, in part due to greater visceral and percent fat levels compared with European women. This observation may in part explain why Asians are at elevated cardiovascular disease risk. Future studies should address the effects of lifestyle factors (physical activity, diet) on plasma IL-6 concentrations in SA women.  相似文献   

14.
Abdominal fat accumulation is a major risk factor for cardiometabolic morbidity and mortality. The purpose of the study is to assess the possibility of developing accurate estimation equations based on body measurements to determine total abdominal (TFA), subcutaneous (SFA) and visceral fat area (VFA). Hungarian volunteers (n = 198) aged between 20 and 81 years were enrolled in the study, which was conducted between July and November 2014. All persons underwent anthropometric measurements and computer tomographic (CT) scanning. Sex-specific multiple linear regression analyses were conducted in a subgroup of 98 participants to generate estimation models, then Bland–Altman's analyses were applied in the cross-validation group to compare their predictive efficiency. The variables best predicting VFA were hip circumference, calf circumference and waist-to-hip ratio (WHR) for males (R2 = 0.713; SEE = 5602.1 mm2) and sagittal abdominal diameter (SAD), WHR, thigh circumference and triceps skinfold for females (R2 = 0.845; SEE = 3835.6 mm2). The SFA prediction equation included SAD, thigh circumference and abdominal skinfold for males (R2 = 0.848; SEE = 4124.1 mm2), body mass index and thigh circumference for females (R2 = 0.861; SEE = 5049.7 mm2). Prediction accuracy was the highest in the case of TFA: hip circumference and WHR for males (R2 = 0.910; SEE = 5637.2 mm2), SAD, thigh circumference and abdominal skinfold for females (R2 = 0.915; SEE = 6197.5 mm2) were used in the equations. The results suggested that deviations in the predictions were independent of the amount of adipose tissue. Estimation of abdominal fat depots based on anthropometric traits could provide a cheap, reliable method in epidemiologic research and public health screening to evaluate the risk of cardiometabolic events.  相似文献   

15.
BackgroundVulvovaginal candidosis is a common infection in young women, and it is associated with high morbidity and high health costs.AimsVulvovaginal candidosis caused by Candida glabrata is a therapeutic challenge due to the acquired resistance of many strains of this species to azole antifungals.MethodsWe present two cases of vaginal candidosis complicated by fluconazole-resistant Candida glabrata, and treated with voriconazole.ResultsBoth patients improved after administration of voriconazole, 400 mg/12 h the first day and then 200 mg every 12 h for 14 days. Their symptoms disappeared and cultures became negative.ConclusionsThese results suggest voriconazole can be used as a therapeutic alternative for this type of candidosis which, although not life threatening, is associated with a high morbidity.  相似文献   

16.
PurposeThe present study was designed to investigate the electromyographic (EMG) response in leg muscles to whole-body vibration while using different body positions and vibration frequencies.MethodsTwenty male sport sciences students voluntarily participated in this single-group, repeated-measures study in which EMG data from the vastus lateralis (VL) and the lateral gastrocnemius (LG) were collected over a total of 36 trials for each subject (4 static positions × 9 frequencies).ResultsWe found that vibration frequency, body position and the muscle stimulated had a significant effect (P-values ranged from 0.001 to 0.031) on the EMG response. Similarly, the muscle × frequency and position × muscle interactions were significant (P < 0.001). Interestingly, the frequency × positions interactions were not significant (P > 0.05).ConclusionsOur results indicate that lower frequencies of vibration (25–35 Hz) result in maximal activation of LG, whereas higher frequencies (45–55 Hz) elicit the highest responses in the VL. In addition, the position P2 (half squat position with the heels raised) is beneficial both for VL and LG, independently of the vibration frequency.  相似文献   

17.
BackgroundThe body mass index (BMI) is based on the original concept that body weight increases as a function of height squared. As an indicator of obesity the modern BMI assumption postulates that adiposity also increases as a function of height in states of positive energy balance.ObjectiveTo evaluate the BMI concept across different adiposity magnitudes, in both children and adults.MethodsWe studied 975 individuals who underwent anthropometric evaluation: 474 children and 501 adults. Tetrapolar bioimpedance analysis was used to assess body fat and lean mass.ResultsBMI significantly correlated with percentage of body fat (%BF; children: r = 0.893; adults: r = 0.878) and with total fat mass (children: r = 0.967; adults: r = 0.953). In children, body weight, fat mass, %BF and waist circumference progressively increased as a function of height squared. In adults body weight increased as a function of height squared, but %BF actually decreased with increasing height both in men (r = −0.406; p < 0.001) and women (r = −0.413; p < 0.001). Most of the BMI variance in adults was explained by a positive correlation of total lean mass with height squared (r2 = 0.709), and by a negative correlation of BMI with total fat mass (r = −0.193).ConclusionsBody weight increases as a function of height squared. However, adiposity progressively increases as a function of height only in children. BMI is not an ideal indicator of obesity in adults since it is significantly influenced by the lean mass, even in obese individuals.  相似文献   

18.
ObjectiveTo investigate the effects of functional electrical stimulation (FES) combined with conventional rehabilitation program on the effort and speed of walking, the surface electromyographic (sEMG) activity and metabolic responses in the management of drop foot in stroke subjects.MethodsFifteen patients with a drop foot resulting from stroke at least 3 months prior to the start of the trial took part in this study. All subjects were treated 1 h a day, 5 days a week, for 12 weeks, including conventional stroke rehabilitation program and received 30 min of FES to the tibialis anterior (TA) muscle of the paretic leg in clinical settings. Baseline and post-treatment measurements were made for temporal and spectral EMG parameters of TA muscle, walking speed, the effort of walking as measured by physiological cost index (PCI) and metabolic responses.ResultsThe experimental results showed a significant improvement in mean-absolute-value (21.7%), root-mean-square (66.3%) and median frequency (10.6%) of TA muscle EMG signal, which reflects increased muscle strength. Mean increase in walking speed was 38.7%, and a reduction in PCI of 34.6% between the beginning and at end of the trial. Improvements were also found in cardiorespiratory responses with reduction in oxygen consumption (24.3%), carbon dioxide production (19.9%), heart rate (7.8%) and energy cost (22.5%) while walking with FES device.ConclusionsThe results indicate that the FES may be a useful therapeutic tool combined with conventional rehabilitation program to improve the muscle strength, walking ability and metabolic responses in the management of drop foot with stroke patients.  相似文献   

19.
Local peripheral cooling (immerson of legs up to the knees into 12°C water) increased heart rate and blood pressure by 10–20% within the first 3–10 min of cooling. During further cooling heart rate remained elevated, while systolic and diastolic blood pressures decreased to the control value. Data on heart rate indicate a permanent activation of the sympathetic nervous system during local cooling.Skin temperatures (measured topically by thermosensors) decreased on some non-cooled areas of the body (fingers, palms and thighs) immediately after the start of local cooling. On the other hand, skin temperatures on chest and forehead were not influenced. During cooling skin temperatures on thighs remained low, but skin temperatures on fingers tended to increase. Changes in skin temperatures on non-cooled areas of the body indicate that a permanent and generalized activation of the sympathetic nervous system occurs during local cooling.Cold induced cycles of vasodilation (CIVD) were observed on fingers, palms and forearms during local cooling. Minute cycles in skin temperatures were observed on forehead, thighs and chest. Minute cycles coincided with those in the heart rate, indicating a permanent, generalized but discontinuous control of vasomotion by the sympathetic nervous system during local cooling.Infrared thermographic recordings from different body areas indicated that local peripheral cooling lowered skin temperatures in all areas of the body within 5 min. Distant areas of the body (extremities) and pectoral muscles showed greater hypothermia than abdominal areas and head. After 10 min of cooling average skin temperatures in all areas of the body returned to the original level and further fluctuated at approximately 10–15 min intervals.Data indicate that during local cooling skin blood flow in all areas of the body surface permanently fluctuates forming a mosaic of dynamic changes in skin temperatures. Since tympanic temperature increases, while skin temperature decreases immediately after the start of the local cooling, it appears that the initial vasoconstrictor response is being controlled independently of the central temperature input.  相似文献   

20.
AimsRepeated treatment with morphine increases antinociceptive effects of delta opioid agonists in rodents by a mechanism that may involve increased cell-surface expression of delta receptors. The present study evaluated effects of repeated morphine treatment on behavioral effects of the delta agonist SNC80 and the mu agonist fentanyl in rhesus monkeys.Main methodsIn an assay of schedule-controlled responding, three monkeys responded for food reinforcement under a fixed-ratio 30 schedule. In an assay of thermal nociception, tail-withdrawal latencies were evaluated in three monkeys using thermal stimulus intensities of 48 and 54 °C. In both assays, the effects of SNC80 (0.032–3.2 mg/kg) and fentanyl (0.001–0.056 mg/kg) were evaluated after repeated treatment with saline or a regimen of morphine doses modeled on the regimen that enhanced delta agonist antinociception and apparent delta receptor availability in previous rodent studies.Key findingsBoth SNC80 and fentanyl dose-dependently decreased rates of schedule-controlled responding, and repeated morphine treatment did not significantly alter these effects. In the assay of thermal nociception, SNC80 had little effect on tail-withdrawal latencies from water heated to 48 or 54 °C, whereas fentanyl increased tail-withdrawal latencies at both temperatures. Repeated morphine tended to increase the antinociceptive effects of SNC80 and to decrease the antinociceptive effects of fentanyl, but these effects of repeated morphine were small and were significant only at the higher stimulus intensity (54 °C).SignificanceThese results provide limited support for the proposition that prior stimulation of mu receptors selectively increases the antinociceptive effects of delta agonists in rhesus monkeys.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号