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Biomedical subjects

F Pons

Publications and source records attributed to F Pons.

At least 235 records · Page 13Linked to original sources
PubMed1983

Myosin light chains in normal and pathological human skeletal muscles.

Thirty-nine human skeletal muscle biopsies from 24 individuals were classified as normal, neuropathic, or myopathic muscle according to classical clinical observations and histopathological properties of the muscles. The content in myosin light chains (LC) of each muscle sample was analyzed by means of a new technique of polyacrylamide gel electrophoresis that gives an improved discrimination, involving isoelectrofocusing of the muscle homogenate for the first dimension and successive migration in a urea-containing gel for the second dimension. Four different LC patterns have been observed in the normal muscles; these four patterns and three different ones have been observed in the pathological muscles. No apparent correlation exists between the myosin LC content and the histochemical fiber typing. It is concluded that the myosin LC are apparently not a useful marker to detect the normality or the pathology of human muscle.

Amyotrophic Lateral Sclerosis↗
PubMed1980

Changes in brain catecholamine levels in human cirrhotic hepatic encephalopathy.

Hepatic encephalopathy (HE) is currently felt to be secondary to a disturbance in the metabolism of cerebral catecholamines with a decline in dopamine and noradrenaline and a rise in the false neurotransmitter octopamine. The aim of this study was to evaluate brain tissue levels of dopamine, noradrenaline, and octopamine in patients with cirrhosis and HE. This study includes 34 patients: 22 were cirrhotic, 12 were control subjects. Among the 22 cirrhotic patients, 19 had HE, three did not. Tissue specimens were obtained at necropsy from the locus niger, caudate nucleus, hypothalamus, thalamus and frontal cortex, and from the frontal cortex during neurosurgical procedures. Our results showed that (1) dopamine and noradrenaline levels are identical in cirrhotic patients with or without HE and in patients without liver disease (P < 0.05); (2) octopamine levels are higher in control subjects than in patients with cirrhosis and HE. In conclusion, there is no decline in dopamine and noradrenaline levels in the brain tissues of cirrhotic patients with HE, and this is in contradication with the animal findings; octopamine levels are not raised. Hepatic encephalopathy in human liver cirrhosis does not seem to be secondary to a disturbance in cerebral catecholamines.

Brain↗
PubMed1980

Treatment of cirrhotic hepatic encephalopathy with L-dopa. A controlled trial.

It has been suggested that hepatic encephalopathy could be due to the accumulation of false neurotransmitters and that the administration of a neurotransmitter precursor such as L-dopa would be beneficial to cirrhotic patients with hepatic encephalopathy. A prospective randomized controlled study was carried out to determine whether L-dopa has any effect on the course of cirrhotic hepatic encephalopathy. L-Dopa, L-Dopa and dopa-decarboxylase inhibitor, or placebo was given orally for 7 days to 75 cirrhotic patients with hepatic encephalopathy. The effect was assessed by clinical parameters as well as serial electroencephalograms. There was no statistically significant difference with respect to clinical improvement or deterioration in patients treated with either L-dopa or L-dopa and dopa-decarboxylase inhibitor or placebo. It is concluded that L-dopa is ineffective in the treatment of cirrhotic hepatic encephalopathy. Inefficacy was not due to late onset of treatment, to poor intestinal absorption of L-dopa, to destruction of L-dopa in the blood, or to impaired passage of L-dopa into the cerebrospinal fluid.

Adult↗
PubMed1979

[Immunocellular response to fetal antigens in patients with hepatoma (author's transl)].

The immunocellular response to fetal antigens was studied in ten patients with hepatocarcinomas. Homogenized extracts of human fetal liver and purified human alpha-fetoprotein were used as antigen substances. The control group included 15 patients with cirrhosis of the liver. The level of circulating T lymphocytes (E-rosettes) was also registered. Patients with hepatocarcinoma showed a definite response to both antigens, determined by the degree of inhibition of leukocyte migration. The migration indices were as follows: x = 0.65 +/- 0.16 for homogenized fetal liver antigen, and x = 0.79 +/- 0.13 for alpha-fetoprotein antigen. These values were 0.93 +/- 0.13 and 0.95 +/- 0.15 respectively in the cirrhotic patients. The differences in the migration indices for the two groups were statistically significant with both antigens (p less than 0.0005 and p less than 0.005). The decrease of the number of T lymphocytes in patients with hepatomas was also significant (p less than 0.005). The determination with homogenized fetal antigen was more sensitive than with alpha-fetoprotein (p less than 0.01). A significant relationship between the severity of the tumor and the immunocellular response could also be seen (r = 0.84; p less than 0.001). Response tended to diminish as the tumor progressed. The disappearance of immunocellular response seemed to depend at least in part on the decreasing number of T lymphocytes, since there was a significant inverse correlation between the two parameters (r = -0.75; p less than 0.01).

Carcinoma, Hepatocellular↗
PubMed1979

Effect of serotonin on cyclic AMP level in rat hypothalamus slices during development.

The effect of serotonin (5-HT) on cyclic AMP levels in rat hypothalamic slices was age-dependent. The sensitivity of the cyclic AMP system to 5 X 10(-5) M 5-HT already existed in the foetus at 21 days of pregnancy. It reached a maximum on the 7th postnatal day and then decreased with age. In adult tissue the response was still present and was antagonized by two serotonergic antagonists (methiothepin and metergoline). When compared to the progressive increase of 5-HT level in the hypothalamus the data suggest a different evolution of serotonergic innervation and of 5-HT receptors.

Aging↗
PubMed1976

[Prenatal development of monoamine neurons in the rat].

The histofluorescence method allows the study of the prenatal development of monoamines neurons in the foetal rat brain. Certain patterns of this development can be defined: the locus niger and the raphe appears fluorescent on the 14th day, the locus coeruleus on the 15th day. These systems differentiate independently in various areas of the neural axis. Their maturation are progressive: first for the DA system, then for the NA and the 5 HT systems. The mechanisms for synthesis and storage of amines precede the complete development of the effector structures.

Age Factors↗
PubMed1976

[Evolvement of systems of serotonin uptake in rat hypothalamus during its development].

Kinetics of 3H serotonin accumulation into slices from hypothalamus have been compared in adult, puppy and foetus rat. In 15 days-old, as in adult rat, there are two components of 5 HT accumulation corresponding to the low and high affinity transport systems. For this latter, Km and Vmax values are much higher in adult than in 15 days old rat (in adult, Km=1,3 X 10(-7) and Vmax=0,33 X 10(-10); in 15 days old rat, Km=0,5 X 10(-7) and Vmax=0,125 X 10(-10)). On the opposite, in the 7 days old rat and in the 21 days old foetus, it is only possible to arbitrarely define one uptake system corresponding to the following apparent values: in the 7 days old rat, Km= 5 X 10(-7) and Vmax=2 X 10(-10), in the foetus, Km=0,2 X 10(-7) and Vmax=0,15 X 10(-10). These results showed important developmental differences in affinity of 3H serotonin to hypothalamus. The low and high affinity uptake systems existing in adult are only individualized in the 15 days old little rat.

Age Factors↗