Evidence for hypoxic depression of CO2-ventilation response in carotid body-resected humans

1991 ◽  
Vol 70 (2) ◽  
pp. 590-593 ◽  
Author(s):  
Y. Honda ◽  
I. Hashizume

Steady-state CO2-ventilation response curves with hyperoxia (end-tidal PO2 greater than 200 Torr) and mild hypoxia (end-tidal PO2 approximately equal to 60 Torr) were compared in five carotid body-resected (BR) patients and five control patients. The data were analyzed by fitting a linear equation, V = S(PETCO2-B), where V is minute ventilation S is the response curve slope. PETCO2 is end-tidal PCO2, and B is the response curve threshold. S slightly increased from hyperoxia to hypoxia in both BR and control groups. On the other hand, B moderately increased with hypoxia in BR patients, whereas it slightly decreased in controls. These changes were all not significant. However, in accordance with the change in B, the response curve to hypoxia at V of 10 1/min was significantly shifted in opposite directions in the two groups, i.e., rightward and leftward shift in BR and control groups, respectively. Thus the average magnitude of V calculated at PETCO2 of 40 Torr in hypoxia was significantly lower in BR patients than in controls (P less than 0.01). We conclude that this hypoxic depression of the CO2-ventilation response found in BR patients may have resulted, at least in part, from modulation of the brain stem neural mechanisms that were elicited by loss of afferent discharges from the carotid body.

2009 ◽  
Vol 24 (5) ◽  
pp. 383-386 ◽  
Author(s):  
Cecília Maria de Carvalho Xavier Holanda ◽  
Monique Batista da Costa ◽  
Natália Chilinque Zambão da Silva ◽  
Maurício Ferreira da Silva Júnior ◽  
Vanessa Santos de Arruda Barbosa ◽  
...  

PURPOSE: Aloe vera is a tropical plant popularly known in Brazil as babosa. We have investigated the effect of aqueous extract of Aloe vera on the biodistribution of Na99mTcO4 and laboratorial parameters in Wistar rats. METHODS: Twelve animals were divided into treated and control groups. In the treated group, Aloe vera was given by gavage (5mg/mL/day) during 10 days. The control group received sorbitol by the same way and period. One hour after the last dose, we injected 0.1mL of Na99mTcO4 by orbital plexus. After 60 min, all the animals were killed. Samples were harvested from the brain, liver, heart, muscle, pancreas, stomach, femur, kidneys, blood, testis and thyroid and the percentage of radioactivity (%ATI/g) was determined. Biochemical dosages were performed. RESULTS: There was a significant increase of %ATI/g in blood, femur, kidneys, liver, stomach, testis and thyroid and also in blood levels of AST and ALT. A significant decrease in levels of glucose, cholesterol, triglycerides, creatinine and urea occurred. The statistical analyses were performed by Mann-Whitney test and T-Student test (p<0.05). CONCLUSION: The aqueous extract of Aloe vera facilitated the uptake of Na99mTcO4 in organs of rats and it was responsible to a high increase of levels of AST and ALT.


1989 ◽  
Vol 66 (3) ◽  
pp. 1108-1112 ◽  
Author(s):  
D. W. Ray ◽  
C. Hernandez ◽  
A. R. Leff ◽  
J. M. Drazen ◽  
J. Solway

We tested the hypothesis that tachykinins mediate hyperpnea-induced bronchoconstriction (HIB) in 28 guinea pigs. Stimulus-response curves to increasing minute ventilation with dry gas were generated in animals depleted of tachykinins by capsaicin pretreatment and in animals pretreated with phosphoramidon, a neutral metalloendopeptidase inhibitor. Sixteen anesthetized guinea pigs received capsaicin (50 mg/kg sc) after aminophylline (10 mg/kg ip) and terbutaline (0.1 mg/kg sc). An additional 12 animals received saline (1 ml sc) instead of capsaicin. One week later, all animals were anesthetized, given propranolol (1 mg/kg iv), and mechanically ventilated (6 ml/kg, 60 breaths/min, 50% O2 in air fully water saturated). Phosphoramidon (0.5 mg iv) was administered to five of the noncapsaicin-treated guinea pigs. Eucapnic dry gas (95% O2–5% CO2) hyperpnea “challenges” were performed by increasing the tidal volume (2–6 ml) and frequency (150 breaths/min) for 5 min. Capsaicin-pretreated animals showed marked attenuation in HIB, with a rightward shift of the stimulus-response curve compared with controls; the estimated tidal volume required to elicit a twofold increase in respiratory system resistance (ES200) was 5.0 ml for capsaicin-pretreated animals vs. 3.7 ml for controls (P less than 0.03). Phosphoramidon-treated animals were more reactive to dry gas hyperpnea compared with control (ES200 = 2.6 ml; P less than 0.0001). Methacholine dose-response curves (10(-11) to 10(-7) mol iv) obtained at the conclusion of the experiments were similar among capsaicin, phosphoramidon, and control groups. These findings implicate tachykinin release as an important mechanism of HIB in guinea pigs.


1996 ◽  
Vol 81 (5) ◽  
pp. 1978-1986 ◽  
Author(s):  
C. Tantucci ◽  
P. Bottini ◽  
M. L. Dottorini ◽  
E. Puxeddu ◽  
G. Casucci ◽  
...  

Tantucci, C., P. Bottini, M. L. Dottorini, E. Puxeddu, G. Casucci, L. Scionti, and C. A. Sorbini. Ventilatory response to exercise in diabetic subjects with autonomic neuropathy. J. Appl. Physiol. 81(5): 1978–1986, 1996.—We have used diabetic autonomic neuropathy as a model of chronic pulmonary denervation to study the ventilatory response to incremental exercise in 20 diabetic subjects, 10 with (Dan+) and 10 without (Dan−) autonomic dysfunction, and in 10 normal control subjects. Although both Dan+ and Dan− subjects achieved lower O2 consumption and CO2 production (V˙co 2) than control subjects at peak of exercise, they attained similar values of either minute ventilation (V˙e) or adjusted ventilation (V˙e/maximal voluntary ventilation). The increment of respiratory rate with increasing adjusted ventilation was much higher in Dan+ than in Dan− and control subjects ( P < 0.05). The slope of the linearV˙e/V˙co 2relationship was 0.032 ± 0.002, 0.027 ± 0.001 ( P < 0.05), and 0.025 ± 0.001 ( P < 0.001) ml/min in Dan+, Dan−, and control subjects, respectively. Both neuromuscular and ventilatory outputs in relation to increasingV˙co 2 were progressively higher in Dan+ than in Dan− and control subjects. At peak of exercise, end-tidal [Formula: see text] was much lower in Dan+ (35.9 ± 1.6 Torr) than in Dan− (42.1 ± 1.7 Torr; P < 0.02) and control (42.1 ± 0.9 Torr; P < 0.005) subjects. We conclude that pulmonary autonomic denervation affects ventilatory response to stressful exercise by excessively increasing respiratory rate and alveolar ventilation. Reduced neural inhibitory modulation from sympathetic pulmonary afferents and/or increased chemosensitivity may be responsible for the higher inspiratory output.


2022 ◽  
Vol 04 (01) ◽  
pp. 686-701
Author(s):  
Magda Hamid KAMBASH ◽  
Nidal Fadel ABBAS ◽  
Esraa Fadel ABBAS

The use of modern teaching strategies aims to develop the practices of ‎female learners inside and outside the classroom, which contributes to ‎changing the role of the student from a negative role to a positive role in ‎general. Therefore, learning strategies have become involved in the ‎application of many educational and teaching programs and curricula, as ‎they greatly help in conveying information to the learner. With less ‎effort and time, except that the material to be learned is theoretical or ‎practical. In light of what the current era is witnessing of a huge ‎knowledge explosion and a wide technological revolution that covered ‎various areas of life, it has become necessary for researchers to be ‎interested in searching for ways to ensure the development of thinking ‎among learners, which is one of the foundations of correct learning, ‎some strategies, means and methods used in the learning process help. ‎To bring the learner to a stage where he can access knowledge on their ‎own by applying that knowledge and using it to overcome the problems ‎they face in their daily lives. He has to use different and multiple ‎methods and methods, and this requires him to be familiar with how ‎learning takes place, and how the teaching methods and means used ‎affect the speed of achieving the goal of the learning process and the ‎success of applying the educational curriculum and achieving its goals‏.‏ One of the features of the modern era is technological progress in ‎various fields and situations of life, as rapid change has become a feature ‎of the era in which we live. There is no doubt that its use affects all ‎aspects of life, including education and teaching, and with this clear ‎progress in the level of mastery of learning skills in sports events around ‎the world, it has become necessary to use learning strategies in ‎programs and curricula for teaching and teaching physical education and ‎learning basic skills for all games and events Sports, including volleyball‏.‏ The researchers found the lack of use of modern strategies in the ‎educational process, and despite their active role in learning basic skills ‎using modern methods, it requires the presence of exercises that ‎contribute to learning basic skills in volleyball, whose weakness emerged ‎from the research sample, which casts a clear shadow on the ‎performance and levels of learners. The aim of the research is to prepare ‎special exercises According to the brain-based learning strategy in ‎learning some basic volleyball skills for students of the second average, ‎and to identify the effect of special exercises according to the brain-‎based learning strategy in learning some basic volleyball skills for ‎students of the second average, and to identify the preference of the ‎experimental and control groups in learning some basic volleyball skills ‎for female students. The second is average. The researchers used the ‎experimental approach for the experimental and control groups, and the ‎research sample was represented by (30) students, then the sample was ‎divided into an experimental group of (15) female students and a control ‎group of (15) female students.


1993 ◽  
Vol 74 (2) ◽  
pp. 590-595 ◽  
Author(s):  
Y. Akiyama ◽  
M. Nishimura ◽  
S. Kobayashi ◽  
A. Yoshioka ◽  
M. Yamamoto ◽  
...  

To clarify whether endogenous opioids modulate the dyspnea intensity and, if so, by what mechanism they act on it, we examined 12 healthy male volunteers aged 19–27 yr for ventilatory and peak mouth pressure (Pm) responses to hypoxic progressive hypercapnia with inspiratory flow-resistive loading after the intravenous infusion of 3 mg of naloxone or saline. The intensity of dyspnea was simultaneously assessed by visual analogue scaling every 15 s. Naloxone administration increased both ventilatory and Pm responses to hypoxic progressive hypercapnia (P < 0.05 for both). The increase in dyspnea intensity for a given increase in end-tidal PCO2 was significantly greater after naloxone infusion than after saline (P < 0.05). However, there were no differences in the increase in dyspnea intensity for a given increase in minute ventilation or Pm. These results suggest that the endogenous opioid system suppresses the respiratory output under a strong, acute respiratory stress in normal adults and that this system may relieve the dyspnea sensation secondary to the suppression of the brain stem respiratory center without specific effects on the processing of respiratory sensations in the higher brain.


1973 ◽  
Vol 51 (5) ◽  
pp. 354-359 ◽  
Author(s):  
Thomas B. Wishart ◽  
Elwood K. Walls

Rats were made hyperphagic by the production of electrolytic lesions in the ventromedial hypothalamus. Following a recovery period during which a rapid weight gain was observed, d-amphetamine was administered intraperitoneally in various dosages, and food intakes, water intakes, and body weight changes were measured after a 3 h feeding period. A dosage of 0.2 mg/kg d-amphetamine had no observable effect. Increasing the dosage to 0.5 or 1.0 mg/kg, however, significantly depressed food and water intakes, and resulted in reduced weight gains in control and experimental animals. Furthermore, the dose–response curves for both experimental and control groups were similar, indicating that d-amphetamine has the same effect in the hyperphagic rat as in the control. It is concluded that amphetamine anorexia is not mediated by the ventromedial hypothalamus.


1978 ◽  
Vol 55 (3) ◽  
pp. 309-316
Author(s):  
K. Prowse ◽  
C. Duvivier ◽  
R. Peslin ◽  
P. Sadoul

1. The respiratory response to inhaled 3% and 6% CO2 was measured in 10 normal subjects after a 3 h acclimatization period to 3% CO2 in an environmental chamber. Control studies were carried out after a 3 h period of breathing air in the chamber. 2. At the end of the acclimatization period studies were carried out during 20 min periods breathing 3% CO2, 6% CO2 and air. 3. At 2-min intervals during the studies measurements were made of tidal volume (Vt), breathing frequency (fR), minute ventilation (V̇e), viscous pulmonary rate of work (Ẇp) and total viscous rate of work across the lungs and apparatus (Ẇt). Blood gas tensions were measured at the end of this period. 4. After acclimatization to 3% CO2 there was a significant shift in the response curves V̇e/Pa,co2 and Ẇt/Pa,co2 such that subjects showed higher Pa,co2 values for given values of V̇e or Ẇt. There was no significant change in the slope of the response curves. 5. No correlation was found between the slope of the response curve after the control period breathing air and the degree of shift of the response curve. 6. There was no difference in respiratory pattern or in pulmonary resistance. 7. Similar results were found in two subjects studied after 24 h acclimatization to 3% CO2 but one subject also showed a significant change in the slope of the V̇e/Pa,co2 curve.


2017 ◽  
Vol 59 (8) ◽  
pp. 973-979 ◽  
Author(s):  
Terhi Tuokkola ◽  
Juha Koikkalainen ◽  
Riitta Parkkola ◽  
Mira Karrasch ◽  
Jyrki Lötjönen ◽  
...  

Background Brain atrophy is associated with mild cognitive impairment (MCI), and by using volumetric and visual analyzing methods, it is possible to differentiate between individuals with progressive MCI (MCIp) and stable MCI (MCIs). Automated analysis methods detect degenerative changes in the brain earlier and more reliably than visual methods. Purpose To detect and evaluate structural brain changes between and within the MCIs, MCIp, and control groups during a two-year follow-up period. Material and Methods Brain magnetic resonance imaging (MRI) scans of 11 participants with MCIs, 18 participants with MCIp, and 84 controls were analyzed by the visual rating method (VRM) and tensor-based morphometry (TBM). Results At baseline, both VRM and TBM differentiated the whole MCI group (combined MCIs and MCIp) and the MCIp group from the control group, but they did not differentiate the MCIs group from the control group. At follow-up, both methods differentiated the MCIp group from the control group, but minor differences between the MCIs and control groups were only seen by TBM. Neuropsychological tests did not find differences between the MCIs and control groups at follow-up. Neither method revealed relevant signs of brain atrophy progression within or between MCI subgroups during the follow-up time. Conclusion Both methods are equally good in the evaluation of structural brain changes in MCI if the groups are sufficiently large and the disease progresses to AD. Only TBM disclosed minor atrophic changes in the MCIs group compared to controls at follow-up. The results need to be confirmed with a large patient group and longer follow-up time.


1975 ◽  
Vol 79 (1) ◽  
pp. 34-42 ◽  
Author(s):  
P. Weisweiler ◽  
P. Schwandt

ABSTRACT In vitro lipolysis was stimulated by porcine pituitary peptides A and B in the rabbit, rat, mouse, and guinea pig. The minimal effective doses were calculated from log dose response curves for free fatty acids and free glycerol liberation. The rabbit was most sensitive responding to 0.008 μg/ml (1.4 pm/ml) peptide A and 0.06 μg/ml (5.3 pm/ml) peptide B respectively. Minipig adipose tissue showed no reaction up to a peptide concentration of 100 μg/ml. After intravenous injection of either peptide at the concentration of 50 μg/kg, FFA and free glycerol increased rapidly in the rabbit with maximal concentrations at 30 min, returning to near normal concentrations after 240 min. Blood glucose concentrations increased continuously in spite of hyperinsulinaemia with a peak concentration at 60 min and complete normalisation after 2 h. Hypertriglyceridaemia and hypocalcaemia were observed in both lipotrophin and control groups. Furthermore, the saline injected rabbits also displayed a slight increase of glucose, FFA, and free glycerol plasma concentrations towards the end of the experiments, suggesting stress stimulated lipolysis. The insulinotrophic effect of both peptides was verified by the fact that injection of lipid emulsion plus heparin led to a comparable increase in FFA and glucose, but to no change in insulin concentrations.


2019 ◽  
Vol 8 (10) ◽  
pp. 1703
Author(s):  
Seung-Jae Lim ◽  
Chan-Woo Park ◽  
Dong-Uk Kim ◽  
Kwangjoon Han ◽  
Minkyu Seo ◽  
...  

Corticosteroids have been widely used in patients with brain tumors to reduce tumor-associated edema and neurological deficits. This study examined the outcomes of total hip arthroplasty (THA) in patients with osteonecrosis of the femoral head (ONFH) following brain tumor surgery. We identified 34 THAs performed in 26 patients with steroid-induced ONFH among 9254 patients undergoing surgical treatment for primary brain tumors. After propensity score matching with demographics, 68 THAs (52 patients) in ONFH unrelated to brain tumors were selected as the control group. At the time of THA, 54% of brain tumor patients had neurological sequelae and 46% had adrenal insufficiency. After THA, patients with brain tumor required longer hospital stay, reported a lower functional score, and showed a higher rate of heterotopic ossification compared to the control group. However, hip pain score improved significantly after THA in the brain tumor group, and did not differ from that of the control group (P-value = 0.168). Major complication rates were similar (2.9% and 1.5% for the brain tumor and control groups, respectively; P-value = 1.000), and implant survivorships were not different at 7 years (100% and 98.1% for the brain tumor and control groups, respectively; P-value = 0.455). Our findings suggest that THA can be safely performed to reduce hip pain in patients with steroid-induced ONFH after surgical treatment of primary brain tumors.


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