Abnormalities in the oxidative metabolism of glucose in human cerebral gliomas have been studied in seven patients using positron emission tomography. Measurements of regional cerebral blood flow and oxygen consumption were obtained using the oxygen-15 steady-state inhalation technique. Values of regional cerebral glucose consumption were obtained using fluorine 18-labeled 2-fluoro-2-deoxy-D-glucose and a simplification of the method of Sokoloff. Functional values were obtained for regions of tumor and brain tissue in the middle cerebral artery territory of the contralateral cortex. Values of regional glucose consumption were calculated for both regions using a value of the lumped constant quoted for normal brain tissue (0.42). Tumor regional cerebral blood flow was comparable to that in the contralateral cortex, whereas regional cerebral oxygen consumption was depressed. This depression resulted in low tumor values of the fractional oxygen extraction ratio (0.21 +/- 0.07), indicating that oxygen supply exceeded the metabolic demand. In contrast, tumor regional cerebral glucose consumption was not depressed and regional glucose extraction ratios were similar for tumor and brain tissue. The metabolic uncoupling between regional oxygen consumption and regional glucose consumption (CMRO2/CMRGlu = 0.24 +/- 0.07 ml of oxygen per milligram of glucose) is indicative of increased aerobic glycolysis.

Adult↗

PubMed1983

Disturbance of oxidative metabolism of glucose in recent human cerebral infarcts.

Eight patients with recent cerebral hemispheric infarction were studied with positron emission tomography and the oxygen-15 steady-state inhalation and [18F]deoxyglucose techniques to obtain values of regional cerebral blood flow, oxygen consumption, and glucose metabolism. The Sokoloff equation, used to calculate glucose metabolism, was simplified to exclude the exponential terms containing the rate constants. A value of the lumped constant quoted for normal brain (0.42) was used for infarcted regions and contralateral hemisphere. Mean regional cerebral blood flow, oxygen consumption, and glucose metabolism were all significantly depressed within the infarcts compared with the mirror regions in the contralateral cerebral hemisphere. The mean fractional extraction of oxygen was low, indicating an adequate supply of oxygen for residual oxidative metabolism. Regional oxygen consumption and glucose metabolism were significantly correlated within the infarcts, but with a relationship of 2 moles of oxygen per mole of glucose--one-third that in the contralateral hemisphere and in normal brain. Although these results suggest that the metabolizing tissue of a recent cerebral infarct utilizes aerobic glycolysis, caution about the validity of this pathophysiological observation is dictated by limitations in current positron emission tomographic tracer methodology.

Adult↗

PubMed1983

Correlations between regional cerebral blood flow and age-related brain atrophy: a quantitative study with computed tomography and the xenon-133 inhalation method.

One hundred and two subjects (40 men and 62 women) neither having a history of neurologic deficits nor showing organic lesions on computed tomographic examination of the brain were studied. Ages of the subjects ranged from 26 to 81 years. Regional cerebral blood flow was measured by the xenon-133 inhalation method, and the volume percentage of brain with respect to the cranial cavity (craniocerebral index) was calculated by means of computer programs. Regional cerebral blood flow was computed as the fast component of two-compartmental analysis and as the initial slope index value. The percentage of each subject's craniocerebral index in relation to the standard for subjects with non-atrophied brains (brain volume index) was calculated as the indicator of brain atrophy. Both the mean brain fast component values and the mean brain initial slope index values correlated closely with the brain volume index in the elderly (r = 0.60, r = 0.62; P less than 0.0001 in each correlation coefficient). Low cerebral blood flow values coincided with loss of brain substance in the final stage of age-related brain atrophy, but not in the intermediate stage.

Adult↗

PubMed1983

Quantitative measurement of glucose utilization in dog brain using positron emission tomogram and 18FDG.

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Animals↗

PubMed1983

[Whole body autoradiography by positron emitting radionuclides].

The technique of freezing whole body autoradiography using positron emitting nuclides has been developed in the present study. Because of rapid decay of positron emitters, a frozen section to contact with a X-ray film must be prepared within a few hours. All the procedures to obtain autoradiograms of rats using 18F-2-deoxy-2-fluoro-D-glucose (18F-FDG) or 11C-glucose-fructose mixture (11C-glucose) were described in detail. In the present technique, exposure must be performed at -20 degrees C to keep a section frozen. Density of X-ray films after exposure at 20 degrees C or -20 degrees C was examined using various radioactive sections. The reduction of the density exposed at -20 degrees C was observed. But the density exposed at -20 degrees C was proportional to the radioactivity. Freezing whole body autoradiography of rats bearing subcutaneous AH109A tumors was performed using 18F-FDG (half life of 109.7 min) and 11C-glucose (half life of 20 min). Density of tumors and other organs on the autoradiogram was comparable with tissue distribution studies of 18F-FDG and 11C-glucose. Freezing whole body autoradiography can be feasible for the analysis of tissue distribution on positron emitting radiopharmaceuticals.

Animals↗

PubMed1982

Experimental study for cancer diagnosis with positron-labeled fluorinated glucose analogs: [18F]-2-fluoro-2-deoxy-D-mannose: a new tracer for cancer detection.

18F-2-fluoro-2-deoxy-D-glucose (18F-FDG) and 18F-2-fluoro-2-deoxy-D-mannose (18F-FDM) were tested as tumor diagnostic agents in a transplantable rat tumor and rabbit tumors. Tissue distribution studies in rats showed high tumor uptakes of both radiopharmaceuticals. The tumor uptake reached 2.65 +/- 0.61% dose 18 dose F-FDG/g and 2.65 +/- 0.81% dose 18F-FDM/g at 60 min and remained relatively constant until 120 min. Blood clearance both 18F-FDG and 18F-FDM was very rapid and tumor-to-blood ratios reached 22.1 and 29.4 at 60 min, respectively. Tumor-to-tissue ratios of both radiopharmaceuticals were very high in most organs, especially in the liver, kidney, and pancreas. Positron emission tomography (PET) of rabbit tumor with 18F-FDM clearly delineated the main tumor, central necrosis, and lymph node metastases. These data suggested that 18F-FDM, which is a by-product of 18F-FDG synthesis was also an excellent cancer diagnostic agent as well as 18F-FDG. This is not only a new feature of 18F-FDM, but also an economical improvement on cancer diagnosis by PET.

Animals↗

PubMed1982

Age-related changes of the cranial bone mineral: a quantitative study with computed tomography.

Age-related changes of the cranial bone mineral in 495 subjects were assessed by computed tomography (CT) in terms of the Hounsfield number. By means of computer programs available in the CT system, the histograms for the bone were obtained. The peak of this histogram for males increased gradually and reached a plateau beyond 20 years of age, while that for females rose rather steeply from age 0 to age 20 and formed a plateau in the 20s and 30s, then declined precipitously from a value of 1164 +/- 143 to a value of 629 +/- 119 in the 70s and older. In the 20s and 30s, the peak for females was greater than that for males. The total pixel number of this histogram was constant after the 20s. The pixel number of the peak for males made a plateau after the 10s, but that for females showed a similar pattern until the 40s, then increased steeply after the 50s. The peak may reflect calcium concentration of the cranial bone, and therefore the skull of the female may store more calcium than that of the male in the 20s and 30s.

Adolescent↗

PubMed1982

Sex difference in brain atrophy during aging; a quantitative study with computed tomography.

Brain atrophy in 154 men and 147 women without neurologic deficits was quantitatively studied by means of computed tomography. The ages ranged from 20 to 79 years. The volume percentage of brain to cranial cavity (Craniocerebral Index, or CCI) was calculated by means of computer programs available in CT systems. The mean CCI in the 20-39 age group was constant at 98.4 per cent in men and 98.7 in women, and this was considered the standard for the CCI in subjects with nonatrophied brains. The percentage of each subject's CCI in relation to this standard in both sexes (Brain Volume Index, or BVI) was calculated as the indicator of brain atrophy. The normal value for BVI was therefore 100 per cent in both sexes. A clear difference was observed between men and women in the process of brain atrophy with increasing age. In men a significant reduction in BVI began in the sixth decade of life (P less than 0.01); thereafter, the decline was gradual and steady through the eighth decade (P less than 0.05). In women, a significant reduction in BVI began in the fifth decade (P less than 0.01) and remained relatively constant during the fifth and sixth decades but declined significantly again in the seventh and eighth decades. In both sexes, remarkable individual differences in brain atrophy were characteristic.

Adult↗

PubMed1981

Age-related brain atrophy and mental deterioration--a study with computed tomography.

The relation of brain atrophy measured with computed tomography (CT) to mental deterioration on living people was studied. A newly improved technique for quantitative measurement of brain atrophy was developed. The pixels inside the head slices were divided into three parts; brain skull, and cerebrospinal fluid according to their CT number. The volume of brain, CSF, and cranial cavity were calculated by counting the number of pixels of each tissue. Results from 130 normal brains showed that the CSF volume was constant at about 16 ml through 20--39 years old. After 40 years the mean CSF volume increased drastically and reached 71 ml in the seventies. The volume of the brain was standardized for comparison between different-sized heads (brain volume index: BVI). The mean BVI decreased with statistical significance after 40 years of age. Mental function of these persons were evaluated using Hasegawa's dementia rating scale for the elderly. Progression of brain atrophy accompanied loss of mental activities (p less than 0.01).

Adult↗

PubMedDate not supplied

Early delineation of cerebral glioma using amino acid positron tracers.

A 56-yr-old housewife with cerebral astrocytoma was reported with positron emission tomography findigns using 11C-methyl-L-methionine (11C-Met) and 18F-fluorophenylalanine (18F-Phe) tracers. 11C-Met and 18F-Phe accumulated intensely in tumor lesions, although CT scans showed only a foggy low-density area. Five years and one month after, an enhancing mass appeared on CT scans. Thus, amino acid tracers may play a important role in the early diagnosis of gliomas.

Astrocytoma↗

PubMedDate not supplied

Is adenomyosis an immune disease?

Adenomyosis is characterized as ectopic endometrial tissues within the myometrium in the uterus. The only difference between adenomyosis and endometriosis is the site of endometriotic tissues: inside or outside of the uterus. It is well known that endometriosis is frequently associated with various autoimmune phenomena. This short review covers various aspects of the immune cascade found in adenomyosis. In adenomyosis, a series of immune responses is activated, including changes in both cellular and humoral immunity, i.e. a strong expression of cell surface antigens or adhesion molecules, an increased number of macrophages or immune cells, and deposition of immunoglobulins and complement components. Furthermore, the disease exhibited high frequency of autoantibodies in peripheral blood. Thus, an immunological 'vicious circle' is formed in the endometrium in adenomyosis. Endometrial cells seem to be under immunological stress, protecting themselves by exposing heat shock proteins. It is concluded that the endometrial environment in adenomyosis differs widely from that in normal fertile women. These abnormal immune responses might be involved in poor reproductive performance in adenomyosis.

Autoantibodies↗

PubMedDate not supplied

Global cerebral glucose utilization is independent of brain size: a PET Study.

Cerebral glucose metabolic rates were measured in 80 normal volunteers by studying the uptake of [18F]deoxyglucose with positron emission tomography (PET), using three PET scanners. A brain size index was determined from the PET images using either length-width or area measurements of the brain at a standard level. There was a significant negative correlation between glucose metabolism per unit volume and brain size that was well described by an inverse functional relationship, implying that the total glucose consumption of the brain is approximately constant. Analyses of men versus women revealed no sex differences in total brain glucose consumption, although there were differences in brain size and in glucose metabolism per unit volume. Similarly there was no significant correlation of total brain glucose consumption with age. The variation with brain size accounted for 46% of the logarithmic intersubject metabolic variance. When comparing global metabolic rates in different subjects, multiplying the rates by a brain size index has the dual advantage of correcting for differences related to brain size and correcting for differences in cerebrospinal fluid volume.

Adolescent↗

PubMedDate not supplied

Cortical motor-sensory hypometabolism in amyotrophic lateral sclerosis: a PET study.

We previously reported generalized cerebral glucose hypometabolism in amyotrophic lateral sclerosis (ALS) patients with upper motor neuron disease, using positron emission tomography (PET) with [18F]2-fluoro-2-deoxy-D-glucose. The present article presents a more detailed regional analysis of the hypometabolism, including measurements of the motor-sensory cortex at higher levels than used earlier. The analysis is based on 19 PET studies of 12 patients with ALS, four of whom had only lower motor neuron involvement, and 11 studies of age-matched control subjects. A brain size correction was included to eliminate differences in metabolism related to brain size but not to pathology. The eight ALS patients with both upper and lower motor neuron disease showed generalized hypometabolism, compared with the normal control subjects, that was greatest in the motor-sensory cortex and putamen. The motor-sensory deficit was strongly correlated with length of disease, and a marked sequential reduction was seen in repeat studies on four of the patients. There was also significant right-left asymmetry in these scans. No cerebral hypometabolism was seen in the four ALS patients without upper motor neuron involvement. Although the observed motor-sensory deficit in ALS is consistent with histopathological findings, the more generalized hypometabolism and the asymmetry suggest more widespread effects.

Adult↗

PubMedDate not supplied

Differential diagnosis of solitary pulmonary nodules with positron emission tomography using [11C]L-methionine.

Two patients with solitary pulmonary nodules, 1.5-2.0 cm in diameter, were studied by positron emission tomography using [11C-Methyl]L-methionine (11C-Met). Case 1 showed high accumulation of 11C-Met in the tumor, and a tumor/muscle ratio of 6.0 suggesting malignancy. Tissue obtained by biopsy revealed a squamous cell carcinoma. Case 2 showed nonspecific isotope accumulation in the tumor, and a tumor/muscle ratio of 1.2 suggesting a benign lesion. Lung biopsy demonstrated granuloma. Positron emission tomography with 11C-Met seems to be useful for the differential diagnosis of solitary lung nodules.

Aged↗