scholarly journals Glucose Metabolic Rate Kinetic Model Parameter Determination in Humans: The Lumped Constants and Rate Constants for [18F]Fluorodeoxyglucose and [11C]Deoxyglucose

1985 ◽  
Vol 5 (2) ◽  
pp. 179-192 ◽  
Author(s):  
M. Reivich ◽  
A. Alavi ◽  
A. Wolf ◽  
J. Fowler ◽  
J. Russell ◽  
...  
Keyword(s):  
Kinetic Model ◽  
Metabolic Rate ◽  
Rate Constants ◽  
Glucose Consumption ◽  
Normal Subjects ◽  
Parameter Determination ◽  
Metabolic Rates ◽  
Mean Values ◽  
Glucose Metabolic Rate ◽  
The Mean

The rate constants and lumped constants (LCs) for [18F]fluorodeoxyglucose ([18F]FDG) and [11C]deoxyglucose ([11C]DG) were determined in humans for the glucose metabolic rate kinetic model used to measure local cerebral glucose consumption. The mean values (±SE) of the LCs for [18F]FDG and [11C]DG are 0.52 ± 0.028 (n = 9) and 0.56 ± 0.043 (n = 6), respectively. The mean values (±SE) of the rate constants k*1, k*2, k*3, and k*4 for [18F]FDG for gray matter are 0.095 ± 0.005, 0.125 ± 0.002, 0.069 ± 0.002, and 0.0055 ± 0.0003, respectively. The corresponding values for white matter are 0.065 ± 0.005, 0.126 ± 0.003, 0.066 ± 0.002, and 0.0054 ± 0.0006, respectively. Using these values and previously published values for the rate constants for [11C]DG, the average whole-brain metabolic rates for glucose in normal subjects measured with [18F]FDG and [11C]DG are 5.66 ± 0.37 (n = 6) and 4.99 ± 0.23 (n = 6) mg/100 g/min, respectively. These values are not significantly different ( t = 1.56, p > 0.10) and agree well with reported values in the literature determined by means of the Kety-Schmidt technique.

scholarly journals Effect of Ischemia on Quantification of Local Cerebral Glucose Metabolic Rate in Man

1981 ◽  
Vol 1 (1) ◽  
pp. 37-51 ◽  
Author(s):  
Randall A. Hawkins ◽  
Michael E. Phelps> ◽  
Sung-Cheng Huang ◽  
David E. Kuhl
Keyword(s):  
Glucose Metabolism ◽  
Metabolic Rate ◽  
Rate Constants ◽  
Normal Values ◽  
Cerebral Glucose Metabolism ◽  
Stroke Rate ◽  
Metabolic Rates ◽  
Lumped Constant ◽  
Glucose Metabolic Rate ◽  
The Stability

The model for quantifying local cerebral glucose metabolic rates originally developed by Sokoloff et al. and modified by Phelps, Huang and co-workers was applied to humans with cerebral ischemia (i.e., stroke). Rate constants for fluorodeoxyglucose were measured in ischemic and nonischemic regions with positron computed tomography. Using measured rate constants for ischemia, the model generates more accurate estimates of local cerebral glucose metabolism as compared to the use of rate constants from normal young adults, because the local metabolic rate is significantly underestimated, and temporal instability of the model is observed when normal values are applied to ischemic regions. A method was also developed to test the stability of the local lumped constant. The estimates of the lumped constant showed no or only small variations between ischemic and nonischemic types. Thus, errors introduced in the calculated local cerebral glucose metabolism by inappropriate rate constants appear to be more significant than those caused by any potential change in the lumped constant in ischemia.

A COMPARISON OF TWO METHODS FOR MEASUREMENT OF ALDOSTERONE SECRETION RATE IN MAN

1966 ◽  
Vol 53 (2) ◽  
pp. 177-188 ◽  
Author(s):  
P. Lund-Johansen ◽  
T. Thorsen ◽  
K. F. Støa
Keyword(s):  
Urinary Excretion ◽  
Normal Subjects ◽  
Secretion Rate ◽  
Aldosterone Secretion ◽  
Simple Method ◽  
Mean Values ◽  
Pathological Conditions ◽  
Significant Difference ◽  
Derivative Method ◽  
The Mean

ABSTRACT A comparison has been made between (A), a relatively simple method for the measurement of aldosterone secretion rate, based on paper chromatography and direct densitometry of the aldosterone spot and (B) a more elaborate isotope derivative method. The mean secretion rate in 9 normal subjects was 112 ± 26 μg per 24 hours (method A) and 135 ± 35 μg per 24 hours (method B). The »secretion rate« in one adrenalectomized subject after the intravenous injection of 250 μg of aldosterone was 230 μg per 24 hours (method A) and 294 μg per 24 hours (method B). There was no significant difference in the mean values, and correlation between the two methods was good (r = 0.80). It is concluded that the densitometric method is suitable for clinical purposes as well as research, being more rapid and less expensive than the isotope derivative method. Method A also measures the urinary excretion of the aldosterone 3-oxo-conjugate, which is of interest in many pathological conditions. The densitometric method is obviously the less sensitive and a prerequisite for its use is an aldosterone secretion of 20—30 μg per 24 hours. Lower values are, however, rare in adults.

Effect of altitude on dietary-induced thermogenesis at rest and during light exercise in man

1978 ◽  
Vol 45 (3) ◽  
pp. 345-349 ◽  
Author(s):  
M. J. Stock ◽  
N. G. Norgan ◽  
A. Ferro-Luzzi ◽  
E. Evans
Keyword(s):  
Metabolic Rate ◽  
Specific Dynamic Action ◽  
Metabolic Rates ◽  
Postprandial Metabolism ◽  
Interindividual Differences ◽  
Liquid Meal ◽  
The Mean ◽  
Monte Rosa ◽  
Hypoxic Exercise ◽  
Made In

Measurements of metabolic rate and the thermic response (specific dynamic action) of a 400-kcal liquid meal were made in six subjects at rest and during light exercise. The tests were conducted before (LA1) and after (LA2) a 3-wk sojourn (HA1, HA2, HA3) at 3,650 m on the Monte Rosa. Fasting metabolic rate at rest increased inittally and then fell, as did fasting and fed exercising metabolic rates. The fall in metabolic rates, but not the initial increases, can be ascribed to the change in body weight. Resting thermic responses at altitude were only slightly lower than normal, although peak values were significantly depressed at HA2 (P less than 0.05). The mean exercising thermic response was also significantly lower at HA2 (P less than 0.05) but recovered in HA3 and LA2. In the time taken for thermic responses to decrease and recover there were interindividual differences that were best explained by the previous altitude experience of the subjects. The possibility of a cardiovascular shift during hypoxic exercise causing depression of postprandial metabolism is discussed.

Foraging energetics and diving behavior of lactating New Zealand sea lions, Phocarctos hookeri

2000 ◽  
Vol 203 (23) ◽  
pp. 3655-3665 ◽  
Author(s):  
D.P. Costa ◽  
N.J. Gales
Keyword(s):  
New Zealand ◽  
Metabolic Rate ◽  
Dive Depth ◽  
Diving Behavior ◽  
Metabolic Rates ◽  
Sea Lion ◽  
Water Turnover ◽  
Sea Lions ◽  
The Mean ◽  
Phocarctos Hookeri

The New Zealand sea lion, Phocarctos hookeri, is the deepest- and longest-diving sea lion. We were interested in whether the diving ability of this animal was related to changes in its at-sea and diving metabolic rates. We measured the metabolic rate, water turnover and diving behavior of 12 lactating New Zealand sea lions at Sandy Bay, Enderby Island, Auckland Islands Group, New Zealand (50 degrees 30′S, 166 degrees 17′E), during January and February 1997 when their pups were between 1 and 2 months old. Metabolic rate (rate of CO(2) production) and water turnover were measured using the (18)O doubly-labeled water technique, and diving behavior was measured with time/depth recorders (TDRs). Mean total body water was 66.0+/−1.1 % (mean +/− s.d.) and mean rate of CO(2) production was 0. 835+/−0.114 ml g(−)(1)h(−)(1), which provides an estimated mass-specific field metabolic rate (FMR) of 5.47+/−0.75 W kg(−)(1). After correction for time on shore, the at-sea FMR was estimated to be 6.65+/−1.09 W kg(−)(1), a value 5.8 times the predicted standard metabolic rate of a terrestrial animal of equal size. The mean maximum dive depth was 353+/−164 m, with a mean diving depth of 124+/−36 m. The mean maximum dive duration was 8.3+/−1.7 min, with an average duration of 3.4+/−0.6 min. The deepest, 550 m, and longest, 11.5 min, dives were made by the largest animal (155 kg). Our results indicate that the deep and long-duration diving ability of New Zealand sea lions is not due to a decreased diving metabolic rate. Individual sea lions that performed deeper dives had lower FMRs, which may result from the use of energetically efficient burst-and-glide locomotion. There are differences in the foraging patterns of deep and shallow divers that may reflect differences in surface swimming, time spent on the surface and/or diet. Our data indicate that, although New Zealand sea lions have increased their O(2) storage capacity, they do not, or cannot, significantly reduce their at-sea metabolic rates and are therefore likely to be operating near their physiological maximum.

Power spectral analysis of the diaphragm electromyogram

1983 ◽  
Vol 54 (6) ◽  
pp. 1579-1584 ◽  
Author(s):  
T. K. Aldrich ◽  
J. M. Adams ◽  
N. S. Arora ◽  
D. F. Rochester
Keyword(s):  
Power Spectrum ◽  
Signal To Noise Ratio ◽  
Normal Subjects ◽  
Chronic Obstructive ◽  
Signal To Noise ◽  
Low Frequencies ◽  
Mean Values ◽  
The Mean ◽  
Noise Ratio ◽  
Diaphragm Fatigue

We studied the power spectrum of the diaphragm electromyogram (EMG) at frequencies between 31 and 246 Hz in four young normal subjects and five patients with chronic obstructive lung disease (COPD). Diaphragm EMGs were analyzed during spontaneous breathing and maximum inspiratory efforts to determine the effect of signal-to-noise ratio on the power spectrum and if treadmill exercise to dyspnea was associated with diaphragm fatigue. We found that the centroid frequencies of the power spectra (fc) were strongly correlated (r = 0.93) with ratios of power at high frequencies to power at low frequencies (H/L) for all subjects. Of the two indices, H/L had the largest standard deviation expressed as a percentage of the mean. The mean values of both of these decreased significantly after exercise, fc from 100.2 to 97.3 and H/L from 1.07 to 0.97. Signal-to-noise ratios were higher in maximal inspiratory efforts and after exercise in normal subjects and higher in COPD patients. The signal-to-noise ratio was correlated negatively with fc and H/L, indicating that these indices of the shape of the power spectrum are influenced by signal strength and noise levels as well as muscle function. We conclude that the fc and H/L index similar qualities of the power spectrum, that they are partially determined by the signal-to-noise ratio, and that, in some cases, exercise to dyspnea is associated with apparently mild diaphragm fatigue.

Metabolic Rate of Female Rats as a Function of Age and Body Size

1956 ◽  
Vol 186 (1) ◽  
pp. 9-12 ◽  
Author(s):  
Max Kleiber ◽  
Arthur H. Smith ◽  
Theodore N. Chernikoff
Keyword(s):  
Body Weight ◽  
Body Size ◽  
Metabolic Rate ◽  
Age Groups ◽  
Female Rats ◽  
Standard Errors ◽  
Normal Female ◽  
Metabolic Rates ◽  
The Mean ◽  
Specific Unit

On the basis of 926 respiration trials, metabolic rates of normal female rats are presented as means of 42 different age groups from birth to 1000 days of age. The means with their standard errors are given for the metabolic rates per rat, per kilogram weight, per unit of the 2/3 power of body weight (surface), and per unit of the 3/4 power of body weight (inter specific unit of metabolic body size). A minimum of 72.6 Cal/kg.3/4 occurs between the ages of 200 and 300 days. An equation with two exponentials predicts the metabolic rate of rats from 77–1000 days of age with a standard deviation between prediction and observation of 2.2% of the mean.

Urinary excretion of glycated protein determined with a specific radioimmunoassay

1991 ◽  
Vol 37 (4) ◽  
pp. 504-507 ◽  
Author(s):  
Chizuko Ukita ◽  
Mitsushige Nishikawa ◽  
Akira Shouzu ◽  
Mitsuo Inada
Keyword(s):  
Urinary Excretion ◽  
Normal Subjects ◽  
Mean Values ◽  
Specific Radioimmunoassay ◽  
Glycated Protein ◽  
Highly Sensitive ◽  
Significant Difference ◽  
Group A ◽  
The Mean ◽  
Group B

Abstract We developed a simple and highly sensitive RIA for glycated protein (GP), and used it to measure GP in serum and urine from 15 normal controls and 30 diabetics (14 with urinary excretion rate of albumin, Ualb less than 15 micrograms/min, group A; nine with 15 less than or equal to Ualb less than or equal to 150 micrograms/min, group B; and seven with Ualb greater than 150 micrograms/min, group C). The mean serum concentration of GP was above normal in all groups of diabetics, and the mean glycation ratios of serum protein (SGP) were higher in groups B and C than in normal subjects. Urinary concentrations of GP also were increased in groups B and C, although the glycation ratio of urinary protein (UGP) was decreased in group C. Consequently, the selectivity of urinary excretion of GP (UGP/SGP) was significantly decreased in group C. Moreover, there was a significant difference in the mean values of selectivity between groups of patients with various degrees of retinopathy. We suggest that measurements of serum and urinary GP are useful to evaluate the progression of diabetic complications.

CD59 Deficient Granulocytes in High Risk Groups of Myelodysplastic Syndromes (MDS).

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 4717-4717
Author(s):  
Georgia Kaiafa ◽  
Vasiliki Tsavdaridou ◽  
Athanasios Papadopoulos ◽  
Christos Savopoulos ◽  
Apostolos Hatzitolios ◽  
...  
Keyword(s):  
Normal Subjects ◽  
Risk Groups ◽  
Mean Value ◽  
Control Group ◽  
Refractory Anaemia ◽  
Mean Values ◽  
Significant Difference ◽  
The Mean ◽  
Group B ◽  
Pnh Clone

Abstract Background: Blood cells are deficient in membrane-bound glycosyl-phosphatidylinositol (GPI)-anchored proteins in paroxysmal nocturnal hemoglobinuria (PNH) because of an acquired disorder of the pluripotent stem cell. CD55 and CD59 antigens are the most common GPI-anchored proteins that are used for the diagnosis of the presence of PNH clone. The association of MDS with PNH is rather controversial. There are few published individual cases of PNH arrived from a previous MDS or MDS following PNH. Aim: Recent studies have demonstrated the existence of PNH clone in some MDS patients. These studies were performed mostly on erythrocytes and to the best of our knowledge they are only 4. Granulocytes appear to be more sensitive markers of PNH clone existence than erythrocytes and therefore we investigate the expression of PNH clone on granulocytes of patients with MDS. Material-Methods: A total number of 95 patients 25–80 yrs old with MDS {A:19 with refractory anaemia (RA), B:9 with refractory anaemia with ring sideroblasts (RARS), C:17 with refractory anaemia with excess blasts (RAEB), D: 12 with refractory anaemia with excess blasts in transformation (RAEB-t) and E: 19 with chronic myelomonocytic leukemia (CMLL)} and 19 healthy donors were included in our study. The presence of GPI-anchored proteins (CD55, CD59)-deficient granulocytes was examined by flow cytometry. For the detection of the PNH clone the commercial kit by Beckman Coulter (cellquant CD55/CD59) was used. Statistical analysis was made by ANOVA, while Robust test was performed because there was no homogeneity of variances by ANOVA. Results: Table 1 shows the percentages of CD55 and CD59 deficient granulocytes in the 5 groups of pts with MDS comparing with the control group. a) Although the mean values of CD55 deficient granulocytes in the groups RAEB, RAEB-t and CMLL were higher enough than those of the normal subjects, there were no statistically significant differences (p>0.10) in the comparison of the mean values of CD55 deficient granulocytes between each group of patients with the control group. b) On the contrary there was a very statistically significant difference in the comparison of the mean value of CD59 deficient granulocytes between the three last groups (C, D and E) of pts with the control group (p< 0.086, p< 0.001 and p<0.001 respectively). The percentages of CD55 and CD59 deficient granulocytes in the 5 groups of patients with MDS and in the control group CD55 CD55 CD59 CD59 Groups N Mean Value Std deviation Mean Value Std deviation A (RA) 19 2.89 2.79 2.91 2.85 B (RARS) 9 1.05 1.14 3.89 3.63 C (RAEB) 17 4.78 4.76 11.75 6.06 D (RAEB-t) 12 4.23 2.85 23.76 8.53 E (CMLL) 19 6.01 4.97 38.26 16.18 Control 19 3.67 2.89 3.67 2.89 Total 95 4.00 3.87 14.44 16.39 Conclusions: There are relatively large CD59 negative subpopulations (mean values 11.75–38.26%) of granulocytes in the last three groups (RAEB, RAEB-t, CMLL) of MDS patients. On the contrary the two low risk forms (RA, RARS) revealed no such populations. Non-expression of CD59 antigen on granulocytes is a more sensitive marker than that of CD55 antigen for the presence of a possible PNH clone in MDS patients.

Effect of Erythropoietin on Platelet Function and Glycoprotein Expression in Patients with MDS.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 3993-3993
Author(s):  
Fotis F.I. Girtovitis ◽  
Dimitrios D. Bougiouklis ◽  
Michel M.P. Makris ◽  
Elefteria E. Pithara ◽  
Pantelis P.E. Makris
Keyword(s):  
Flow Cytometry ◽  
Platelet Function ◽  
Normal Subjects ◽  
Mean Value ◽  
Special Treatment ◽  
Recombinant Erythropoietin ◽  
Mean Values ◽  
Human Recombinant Erythropoietin ◽  
The Mean ◽  
The Difference

Abstract Aim: We decide to study the effect of erythropoietin on the platelet function and glycoproteins expression in patients (pts) with myelodysplastic syndrome (MDS). All patients suffered from primary MDS but none of them received any special treatment. From our study pts that suffered from diseases or they were receiving medication that affect the function of platelets were excluded. Furthermore pts with platelet count&lt;50,000/μl were excluded also because we were unable to check the aggregation of platelets. Material: 41 subjects were studied, 15 normal subject (10 men and 5 women mean age 66,6±14 years old)and 26 pts (17 men and 9 women with mean age70,9±7,4 years old) suffered from all types of MDS according to FAB criteria (9 with RA, 3 with RARS, 7 RAEB, 4 with CMML and 3 with RAEB-t). We divided them in 2 groups: 1st - 7 Pts receiving human recombinant erythropoietin (rEPO) with mean dose 30.000 iu subcutaneous weekly and 2nd - 19 without rEPO. Methods. 1- The platelet function was studied in Platelet Ionized Calcium Aggregometer (PICA) using Ristocetin, ADP, Collagen and Adrenalin as stimulators. 2- The expression of platelet glycoproteins (GPIb, IX, IIb, IIIa and P-selectin) was studied using the flow cytometry and special monoclonal antibodies. This way the percentage of glycoprotein expressed in platelet membrane and MFI were estimated. We performed the statistical analysis of our results using the t-test with common standard deviation.. Results: our results concerning the aggregation test and flow cytometry are presented in tables 1,2 and 3. From the study of our results we can see that while the decrease of aggregation between the patients under EPO and normal subjects is statistically non significant (p&lt;0.1)the decrease of the corresponding values between the pts that did not received EPO and normal subjects was statistically very significant for all stimulators (p &lt;0,001). pts under EPO show an important increase of platelet expressing GPIIb percentage grater than the expressed percentage of patients without EPO (60% vs. 46,1% correspondingly, p&lt;0.001). The difference of expressed MFI was not statistically significant. Conclusion: The findings of our study show us that erythropoietin improves the function of platelets in patients with MDS, probably through the increase of platelet percentage which express glycoproteins. Table 1 Comparison of the mean value of aggregation between the groups Table 2 Comparison of the mean values of the platelets expressing corresponding glycoproteins percentage between the groups Table 3 Comparison of the mean value of MFI between the groups

scholarly journals Characteristics of Down syndrome subjects in a Saudi sample

2013 ◽  
Vol 84 (1) ◽  
pp. 30-37 ◽  
Author(s):  
Mohammed A. Korayem ◽  
Eman A. AlKofide
Keyword(s):  
Down Syndrome ◽  
Normal Subjects ◽  
Cranial Base ◽  
Effective Length ◽  
Categorical Variables ◽  
Mean Values ◽  
Nasolabial Angle ◽  
The Mean ◽  
Student’S T ◽  
Student’S T Test

ABSTRACT Objective: To compare the cephalometric characteristics of Down syndrome (DS) subjects with those of normal subjects. Materials and Methods: Cephalometric radiographs of 60 Saudi DS subjects and 60 controls with specific inclusion criteria were used. Descriptive statistics were used to describe the quantitative and categorical variables, and the Student's t-test for two independent samples was used to compare the mean values of quantitative variables. Results: SBa and SN were higher in controls than in DS subjects, whereas the NSBa was significantly higher in DS subjects than in controls. SNA, Co-A, ANB, and A-Na perp of controls were higher than the DS subjects. However, SN-MP, PP-MP, ANS-Me/N-Me, Y-axis, and Ar-Go-Me of the DS subjects were higher than those of the controls. In addition, U1-NA, U1-NA mm, L1-NB, and L1-NB mm of the DS subjects were also higher than the controls with a more acute U1-L1 angle in DS. NLA was larger in controls than in DS, whereas LL-E and UL-E of the DS subjects were higher than the controls. Conclusions: Differences between DS subjects and controls can be found when examining cephalometric radiographs. Anterior and posterior cranial base lengths are shorter with a backward inclination of the posterior cranial base in DS subjects. DS subjects present with a retrognathic maxilla and shorter effective length, with an increased LFH and a hyperdivergent mandible. Bimaxillary dental protrusion can also be expected in DS subjects with prominent lips and a reduced nasolabial angle.

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