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Mean Age 31 Years (mean + age_31_year)

Distribution by Scientific Domains

Medical Sciences	75%

Selected Abstracts

Red Cell Pulmonary Transit Times Through the Healthy Human Lung

EXPERIMENTAL PHYSIOLOGY, Issue 2 2003
G. S. Zavorsky
It has previously been postulated that rapid red cell capillary transit through the human lung plays a role in the mechanism of diffusion limitation in some endurance athletes. Methodological limitations currently prevent researchers from directly measuring pulmonary capillary transit times in humans during exercise; however, first pass radionuclide cardiography allows direct measurement of red blood cell (RBC) transit times through the whole lung at various exercise intensities. We examined the relationship between mean whole lung red cell pulmonary transit times (cardiopulmonary transit times or CPTT) and different levels of flow in 88 healthy humans (76 males, 12 females) from several studies (mean age 31 years). The pooled data suggest that the relationship between CPTT and cardiac index (CI), beginning at rest and progressing through to maximum exercise demonstrates that CPTT reaches its minimum value when CI is about 8.1 l m2 min,1 (2.5-3 times the CI value at rest), and does not significantly change with further increases in CI. Cardiopulmonary blood volume (CPBV) index also does not change significantly until CI reaches 2.5 to 3 times the CI value at rest and then increases roughly linearly after that point. Consequently, the systematic increase in CPBV index with increasing pulmonary blood flow between 8.1 and 20 l m2 min,1 displays an adaptive response of the cardiopulmonary system by augmenting CPBV (and perhaps pulmonary capillary blood volume through distension and recruitment) to offset the reduction in CPTT, as no significant difference in mean CPTT is observed between these levels of flow (P > 0.05). Therefore, these data demonstrate that CPBV does not reach maximum capacity during strenuous or maximum exercise. This does not support the principle of quarter-power allometric scaling for flow when explaining modifications during exercise. Therefore, we speculate that the observed relationships between CPTT, CBPV index and flow may prevent mean CPTT (and perhaps mean pulmonary capillary transit times) from decreasing below the threshold time required for oxygenation. [source]

Alteration of inflammatory response following small-volume resuscitation

BRITISH JOURNAL OF SURGERY (NOW INCLUDES EUROPEAN JOURNAL OF SURGERY), Issue 7 2000
F. Gebhard
Background Small-volume resuscitation is rather effective in the primary volume treatment of major trauma. Blood pressure stabilizing effects occur immediately but last for a limited period only. Influences on inflammatory reactions in humans have not been reported so far. This prospective randomized study therefore analysed the inflammatory response in the very early (pre)clinical period after administration of crystalloids plus starch, hyperosmolar/hyperoncotic starch and lyophilized plasma solutions. Methods Upon approval of the ethics committee, 41 patients were enrolled with multiple injuries (injury severity score (ISS) mean 34 (range 9,75)). The patients received randomly either standard solutions, i.e. starch plus crystalloids (group C (control); n = 14), hyperosmolar/hyperoncotic starch (group S (small volume); n = 14) or lyophilized plasma (group L (lyoplasma); n = 13). Subsets were performed according to the different solutions as well as to the severity of trauma (ISS below 17, 18,31, 32 or more) and survivors/non-survivors. The first blood sample was obtained at the scene of the accident before cardiopulmonary resuscitation, when appropriate. Subsequently, blood samples were collected hourly. All samples were spun immediately at 4°C and stored at ,70°C. Interleukin (IL) 6 as well as several different prostaglandins (PGI2, thromboxane A2, PGE2) were determined to characterize the overall inflammatory response. Results Eleven casualties (seven men and four women, mean age 31 years) died because of major trauma within 24 h after the incident. In all patients IL-6 levels promptly increased within the first 2 h, most pronounced in patients with the severest trauma (ISS greater than 32) and non-survivors. Patients in groups C and S had a comparable time course of IL-6 plasma levels with a slightly higher release in minor injuries (ISS less than 30). The same was true for prostaglandins. In contrast, patients in group L had clearly higher IL-6 concentrations during the first 2,12 h, again most pronounced in those with the severest trauma (ISS greater than 32). Conclusion These results demonstrate that the early systemic inflammatory response after small-volume resuscitation is rather similar to that of patients infused with standard-volume therapy after trauma. In contrast, lyoplasma seems to increase the inflammatory response regardless of the injury severity. © 2000 British Journal of Surgery Society Ltd [source]

Hyperthyroidism is characterized by both increased sympathetic and decreased vagal modulation of heart rate: evidence from spectral analysis of heart rate variability

CLINICAL ENDOCRINOLOGY, Issue 6 2006
Jin-Long Chen
Summary Objective, The clinical manifestations of hyperthyroidism resemble those of the hyperadrenergic state. This study was designed to evaluate the impact of hyperthyroidism on the autonomic nervous system (ANS) and to investigate the relationship between serum thyroid hormone concentrations and parameters of spectral heart rate variability (HRV) analysis in hyperthyroidism. Design and patients, Thirty-two hyperthyroid Graves' disease patients (mean age 31 years) and 32 sex-, age-, and body mass index (BMI)-matched normal control subjects were recruited to receive one-channel electrocardiogram (ECG) recording. Measurements, The cardiac autonomic nervous function was evaluated by the spectral analysis of HRV, which indicates the autonomic modulation of the sinus node. The correlation coefficients between serum thyroid hormone concentrations and parameters of the spectral HRV analysis were also computed. Results, The hyperthyroid patients revealed significant differences (P < 0·001) compared with the controls in the following HRV parameters: a decrease in total power (TP), very low frequency power (VLF), low frequency power (LF), high frequency power (HF), and HF in normalized units (HF%); and an increase in LF in normalized units (LF%) and in the ratio of LF to HF (LF/HF). After correction of hyperthyroidism in 28 patients, all of the above parameters were restored to levels comparable to those of the controls. In addition, serum thyroid hormone concentrations showed significant correlations with spectral HRV parameters. Conclusions, Hyperthyroidism is in a sympathovagal imbalanced state, characterized by both increased sympathetic and decreased vagal modulation of the heart rate. These autonomic dysfunctions can be detected simultaneously by spectral analysis of HRV, and the spectral HRV parameters could reflect the disease severity in hyperthyroid patients. [source]

A randomised clinical trial of turbinectomy for compensatory turbinate hypertrophy in patients with anterior septal deviations

CLINICAL OTOLARYNGOLOGY, Issue 6 2000
D A. Nunez
Turbinectomy is performed at the time of nasal septal surgery by many otolaryngologists. One reason given for this procedure is the presence of a hypertrophied contralateral inferior turbinate. A randomised trial was undertaken to evaluate the relief of nasal obstruction following contralateral turbinectomy with septal surgery. Patients presenting with nasal obstruction who had a unilateral septal deviation and contralateral inferior turbinate enlargement were prospectively randomized to contralateral turbinectomy or no turbinate surgery at the time of septal surgery. Questionnaires and active anterior rhinomanometry were used for evaluation. Twenty-six patients (mean age 31 years) demonstrated a reduction in subjective and objective measures of nasal obstruction (P < 0.05) 8 weeks after operation. There was no intergroup difference, the median total decongested nasal resistance postoperatively in the non-turbinectomized patients was 0.17 kPal,1 s and 0.21 kPal,1 s in the turbinectomized patients. Contralateral inferior turbinectomy does not add to the relief of nasal obstruction beyond that attained by septal surgery in these patients. [source]