Selective reduction of monoamine oxidase A and B in the frontal cortex of subordinate rats

We have previously shown that subordination causes a reduction in the levels of 5-hydroxytryptamine and dopamine selectively in the frontal cortex [6]. These monoamines are catabolised mainly by the enzyme monoamine oxidase (MAO) which exists in two isoforms; MAO-A and MAO-B. The present study was carried out to determine whether there is any change in the activity of these two iso-enzymes induced by subordination and if any such alteration is confined to the frontal cortex. The animal model of dominance-subordination used was a worker-parasite paradigm in male Wistar rats. The enzyme activities were measured in five brain regions, the frontal cortex, entorhinal cortex, hippocampus, hypothalamus and striatum, using kynuramine as the substrate. Clorgyline and L-deprenyl were used in vitro to block the activities of MAO-A and MAO-B, respectively. There was a significant (P < 0.001) reduction in the activity of MAO-A as well as MAO-B selectively in the frontal cortex of the subordinate animals. This finding may suggest a reduced neurotransmitter turnover in the serotonergic and dopaminergic neurons terminating in the frontal cortex.     

The monoamine regulon including syntheses of arylsulfatase and monoamine oxidase in bacteria

Bacterial cells respond to monoamine compounds, such as tyramine, dopamine, octopamine, or norepinephrine, and induce the syntheses of tyramine oxidase encoded by tynA and monoamine oxidase encoded by maoA. These monoamine compounds also derepress the synthesis of atsA-specified arylsulfatase that is repressed by sulfur compounds. These complex mechanisms of regulons regulated by monoamine and sulfur compounds has been analyzed by cloning and characterization of genes that are involved in the repression and derepression of the synthesis of arylsulfatase. The atsA gene forms an operon with the atsB gene, which encodes an activator of the expression of atsA. The negative regulator gene for arylsulfatase was found to code for dihydrofolate reductase (folA). The maoA gene forms an operon with the maoC gene, which has similarity to a dehydrogenase involved in the tyramine metabolism. The moaF gene encoding a 30-kDa protein, which is induced by tyramine, also forms an operon with the moaE gene. Finally, the moaR gene, which is induced by monoamine, was found to play a central role in the positive regulation of the expression of the monoamine regulon (moa) including the atsBA, maoCA, moaEF, and tyn operons. The moaR expression is subject to autogenous regulation and to cAMP-CRP control. The MoaR protein has a helix-turn-helix motif in its C terminus. Thus, the MoaR protein probably regulates the operons by binding to the regulatory region of the moa regulon.     

Carcinoma of the thyroid gland

Hypogonadotropic hypogonadism with anosmia was found in a 38 year old female. Cardiac abnormalities were manifested by a second degree heart block as well as a conduction delay below the AV node. Striking T wave inversions developed in the absence of any symptoms. These changes probably reflect a central nervous system defect.     

Platelet monoamine oxidase, plasma benzylamine oxidase and liver mixed function oxidase in cirrhotic patients

Because it has been suggested that an accumulation of false neurochemical transmitters plays a part in the cardiovascular and neurological complications of cirrhosis it appeared worthwhile to study the level of monoamine oxidase in the liver and platelets of cirrhotic patients. In fact a decrease of such activities might explain the increase of false neurotransmitters observed in cirrhotic patients. Other enzyme were also tested: the plasma benzylamine oxidase activity and the liver mixed function oxidases. 13 cases of severe cirrhosis (B, C according to Child classification) and 10 cases of less severe cirrhosis (A according to Child classification) were studied in comparison to patients affected by cholelithiasis. A defect in the level of monoamine oxidase activity of platelets and liver was observed in some cirrhotic patients together with a decrease of the level of the liver mixed function oxidases.     

Hodgkin''s disease in the thyroid gland

Gaining a sufficient exposure for aortic valve surgery after previous coronary artery bypass grafting (CABG) has been a problem due to the patent saphenous vein grafts. Although a patient had had CABG twice we performed aortic valve replacement (AVR) with almost the usual exposure. We attached the proximal anastomosis in a more distal position of the ascending aorta than usual, at the first CABG, as he was diagnosed to have mild aortic valve stenosis prior to surgery. We consider this method allows easier AVR after previous CABG when the patient is diagnosed with mild aortic valve stenosis before CABG.     

Effect of dietary trans fatty acids on cholinesterase and monoamine oxidase activities in different organs of rats

The effect of trans fatty acids and essential fatty acid deficiency upon the activities of cholinesterase and monoamine oxidase in livers, hearts, brains and lungs of rats was studied. This study was performed using three groups of male albino rats. Two out of these three groups were fed essential fatty acid low diets containing 10% hydrogenated coconut oil (HCNO) or margarine stock (MS, partially hydrogenated soybean oil) while the third group was fed an adequate supply of essential fatty acids through a diet containing 10% corn oil (CO). In the group of rats fed HCNO the activities of cholinesterase and monoamine oxidase in their livers, hearts, brains and lungs were not significantly different from those of the control group fed CO. In the group of rats fed MS, the activity of cholinesterase was significantly decreased in the livers, hearts and brains, but not affected in the lungs, while the activity of monoamine oxidase was significantly decreased in the livers and hearts but not affected in the brains and lungs as compared to the control group fed CO. The levels of serum total lipids, total cholesterol and triglycerides were elevated in both groups of rats fed HCNO or MS than in the group fed CO, but this elevation was more highly significant in the group fed MS than in the group fed HCNO.     

Platelet monoamine oxidase activity in subgroups of schizophrenic disorders

This article summarizes findings from a series of studies that examined platelet monoamine oxidase (MAO) activity in patients with nonaffective schizophrenic disorders and schizophrenia-related depressions. The findings indicate that mean platelet MAO activity was not different from control values in the subgroup of nonaffective schizophrenic disorders without auditory hallucinations (that is, the S-1 subgroup). However, mean platelet MAO activity was reduced in the subgroup of nonaffective schizophrenic disorders characterized by the presence of auditory hallucinations often occurring in conjunction with paranoid features (that is, the S-2 subgroup). Moreover, we found that mean platelet MAO activity was increased in schizophrenia-related depressions characterized by histories of chronic asocial, eccentric, or bizarre behavior.     

Teratoma of the thyroid gland in children

Two cases of teratoma of the thyroid gland occurring in children are presented. Both tumors were discovered shortly after birth and were not associated with clinical hypothyroidism. One of the patients was thoroughly studied from the endocrinological point of view utilizing several techniques. There was some iodine uptake by the gland, formation of tirosine and thyroid hormones as well as their release into the blood serum. The clinical and pathological features of teratoma of the thyroid are discussed.     

Carcinoma of the thyroid gland in Iran

Of the 1698 cases of thyroid disease seen during the 17 years 1956-72 in the Taj Cancer Institute, Tehran, 398 were cases of carcinoma, an incidence of 23.4 per cent. The factors involved in this high incidence of malignancy are discussed and the treatment of these patients is described.     

Specific binding of 3n-melatonin with plasma cell membrane in rats thyroid gland

The present study compared the Kato-Katz thick smear and formol ether sedimentation techniques in the diagnosis of Schistosoma mansoni infections. A stool specimen was collected from 915 individuals representing a high prevalence community (63.3%) and from 471 individuals representing a relatively low prevalence village (40%). The overall sensitivity of a single Kato-Katz smear was 70.8%, and it increased with each additional slide to reach 91.7% on examining four smears. However, the sensitivity was 83.3% when using the formol ether sedimentation technique. In terms of quantitative analysis, the geometric mean egg count was 94 eggs per gram (epg) of stool by two Kato-Katz smears, and 43 epg by the sedimentation technique. This means that more than 50% of eggs were missed when using the sedimentation technique, a fact that should be taken into consideration when relating infection level with morbidity.     

Anaplastic carcinomas of the thyroid gland

Incubation of ampicillin with whole cells of Streptomyces sp. DRS-1 resulted in accumulation of four compounds different from ampicillin. One of them was isolated, purified and partially characterized. On the basis of spectroscopic characteristics, RF value and antibacterial activity the compound was identified as cephalexin. It could also be obtained from ampicillin by using crude protein extract of the strain.     

Critical evaluation of measurement of platelet monoamine oxidase in man

Some biochemical characteristics such as substrate specificity, substrate affinity and inhibitor sensitivity of monoamine oxidase of human blood platelets were investigated. Tyramine, tryptamine and beta-phenylethylamine were used as substrates. The apparent Michaelis constants, maximal velocity rates and I50 for the inhibitor tranylcypromine were determined. The data were analyzed according to Lineweaver-Burk and Dixon. The influence of amitriptyline, a prototype of tricyclic antidepressants, on the selected variables (Km, V, I50), was studied. The parameters investigated showed remarkably low interindividual differences when healthy volunteers were tested. The inhibitor activity of amitriptyline towards platelet monoamine oxidase depends on the substrate used. Amitriptyline concentrations which showed a pronounced effect on the enzyme characteristics are significantly higher than plasma levels of the drug found under therapeutic conditions.