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Biomedical subjects

P Mehraein

Publications and source records attributed to P Mehraein.

At least 73 records · Page 4Linked to original sources
PubMed1982

[On the biological behaviour of the rare malignant plexus papilloma in childhood: long-term observations in two operated cases].

Only a few verified cases of malignant papilloma of the choroid plexus have been described in the literature. The biological nature and prognosis of those tumours are not well known. Two cases of our own material are presented in whom large tumours of the lateral ventricles have been removed. One patient was 9 months and the other seven years old at the time of operation. The clinical follow-up period was seven years. Computer-tomography controls did not reveal any sign of recurrence. The published cases are reviewed until 1981. Their clinical aspects, the histological features and the nature of these rare tumours are discussed.

Cerebral Ventricle Neoplasms↗
PubMed1982

Pick's disease and head trauma.

This is a clinico-pathological study of the relationship between Pick's disease and head trauma. Seven of our autopsied cases with Pick's disease had clinical histories and/or neuropathological evidence of a head trauma. Two cases showed no pathological evidence of traumatic brain damage, although they had clinical histories of a head trauma. The other five cases had old contusions located chiefly on the frontal and temporal bases. As far as we know, there is no reported case of Pick's disease with old contusions in the literature. Therefore, our five cases are of great importance to the study of the relationship between Pick's atrophic processes and traumatic brain damage. The conclusion of our study is that traumatic brain damage involving the atrophy centers of Pick's disease or the adjacent regions could evoke or intensify Pick's atrophic processes.

Adult↗
PubMed1982

A new rat mutant with defective overhairs and spongy degeneration of the central nervous system: clinical and pathologic studies.

A new spontaneous autosomal recessive mutation with a nervous disorder and a hair anomaly occurred in a colony of Sprague Dawley rats. The animals developed a generalized body tremor at about 15 days of age, and with increasing age a progressive flaccid paresis occurred. Light microscopy revealed spongy changes in the central nervous system. The mutant was designated zitter rat (zi).

Animals↗
PubMed1981

Oncogenic activity of the BK type of human papova virus in newborn Wistar rats.

The oncogenic potential of the human papova virus BK (= BKV) has been examined in newborn Wistar rats. 12 of 37 animals inoculated with BKV s.c. and 7 of 40 animals inoculated with BKV i.c. developed tumors of various histological types. The latency periods ranged from 6 to 18 months. The BKV etiology of tumors was supported by detection of BKV T antigen in cells of established tumor lines by means of indirect immunofluorescence. No tumors appeared in animals given injections of saline instead of virus. BKV T antibodies were detected in sera of 100 per cent of animals bearing tumors but no in sera of control animals. Only 3 of 77 BKV infected and none of the control animals developed spontaneous tumors (adenomas).

Animals↗
PubMed1980

Pro-opiocortin fragments in human and rat brain: beta-endorphin and alpha-MSH are the predominant peptides.

The 'pro-opiocortin' fragments, beta-lipotropin, beta-endorphin, ACTH and alpha-MSH, were estimated in discrete areas of rat and human brain and pituitaries by means of radioimmunoassay in combination with gelfiltration. These peptides exhibited parallel patterns of distribution, but with beta-endorphin and alpha-MSH predominant in the brain of rat and man, and, in contrast, their respective precursors. beta-LPH and ACTH predominant in the adenohypophysis of rat and man. These data may be indicative of important differences in post-translational processing of 'pro-opiocortin' between these contrasting tissues.

Adrenocorticotropic Hormone↗
PubMed1980

Spine distribution along the apical dendrites of the pyramidal neurons in Down's syndrome. A quantitative Golgi study.

The number of spines along the apical dendrites of the pyramidal neurons in the hippocampal and cingulate gyri were counted on Golgi preparations of the brains of seven cases of Down's syndrome; they did not show neuropathological senile changes. The number of spines in the middle and distal segments of the apical dendrites of Down's syndrome group were significantly fewer than in those of the control group. The number of spines in aged noncharacteristic mentally retarded cases were not decreaed compared with the controls. The diminution of spines in Down's syndrome is considered to be rather specific in this condition and is not a common finding in other types of mental retardation. It might also be one of the early changes of dendritic degeneration related to senile plaque formation.

Adolescent↗
PubMed1980

Extrahypothalamic corticotropin and alpha-melanotropin in human brain.

The distribution of corticotropin (ACTH) and alpha-melanotropin (alpha-MSH) in human brain was investigated by radioimmunoassay using an antiserum which recognized h-ACTH1-39 and alpha-MSH to an equal degree on a molar basis. Significant amounts of material, which migrated on calibrated Sephadex G-50 columns as synthetic h-ACTH1-39 and synthetic alpha-MSH, were detected in distinct brain areas. The highest concentrations of ACTH and alpha-MSH were found in the diencephalon (hypothalamus 4.2 and 12.5 pmol/g wet weight, respectively) and in midbrain (periaqueductal gray 0.5 and 1.7 pmol/g, respectively) and smaller quantities in the rhombencephalon and telencephalon. The ACTH concentration in human pituitary (adenohypophysis) was 10(4)-fold greater than that in the hypothalamus. alpha-MSH was confined to the midpart and/or stalk region of the pituitary.

Adrenocorticotropic Hormone↗
PubMed1979

Regional distribution of methionine-enkephalin- and beta-endorphin-like immunoreactivity in human brain and pituitary.

Concentrations of methionine-enkephalin- (Met-enkephalin) and beta-endorphin-like immunoreactivities were determined in 33 areas of human brain and pituitary using highly sensitive radioimmunoassays in combination with affinity chromatography for the purification of beta-endorphin. It was found that they have quite different distribution patterns, suggesting the existence of both endorphins in independent systems in the central nervous system. Determination of Met-enkephalin and beta-endorphin immunoreactivities in chronic alcoholics and opiate-dependent subjects revealed no gross changes in comparison to the normal subjects.

Adult↗
PubMed1979

Dementia-Parkinsonism syndrome with numerous Lewy bodies and senile plaques in cerebral cortex.

Five cases of age range 62-72 years with progressive dementia and muscular rigidity are reported and discussed from the clinicopathologic point of view. The neuropathology of these cases was characterized by the widespread occurrence of Lewy bodies (LB) in the CNS as well as the presence of senile changes. The presence of numerous LB in the cerebral cortex and basal ganglia was especially characteristic, although their distribution pattern in the diencephalon and brain stem was identical to that found in paralysis agitans. On the other hand, the presence of senile changes in the cerebral cortex was almost identical to the neuropathology of senile dementia or Alzheimer's disease. Nosologically, the present cases may represent either a combination of atypical paralysis agitans with senile dementia and Alzheimer's disease, or a new disease.

Aged↗
PubMed1978

[Amyotrophic lateral sclerosis with degeneration of thalamus and substantia nigra (author's transl)].

A 40-year-old man suffering from amyotrophic lateral sclerosis with symmetrical degeneration of the thalamus and the substantia nigra is reported. The distribution pattern of the thalamic degeneration in the present case was characteristic in that the Nucleus centralis was the severest affected of the thalamic nuclei. As far as we know, there is no such case of amyotrophic lateral sclerosis in the literature. Nosologically, this case may represent a form of combined heredosystemic degeneration.

Adult↗
PubMed1976

[Neuroanatomical correlates of the amnestic syndrome (author's transl)].

An amnestic syndrome can be observed in several organic brain disorders. This paper tries to elucidate the anatomical substrate of this syndrome by investigation of the brain in 168 carefully examined cases. These included 55 cases of brain tumor, 8 of encephalitis, 55 of Wernicke encephalopathy, and 50 of Alzheimers disease or senile dementia. All these patients had shown a prominent amnestic syndrome. Despite the diversity of the organic brain pathology the anatomical findings in all cases were bilateral lesions of variable intensity in one or more of the following structures: Ammon's horn, fornix, and corpus mammillare. In conformity with the literature it is a assumed that preservation of these structures must be of great significance for the processes of mnemonic registration, integration, and recall. A bilateral lesion in all or some of these centers and their connections causes, as a rule, disturbances of memory. This conclusion, however, does not rule out the possibility that similar memory disturbances may occur following other organic lesions, localized elsewhere in the brain.

Adult↗
PubMed1976

[Physiological and pathological aging of the brain].

Also in the old age, the capability for a meaningful arrangement of life is dependent on the functional integrity of the brain. The processes of senile involution occurring physiologically do not exclude such a possibility. In normal aging, the reduction in the number of nerve cells and dendritic spines is small compared to pathological aging. There are no indications for transitions between normal and pathological aging. Senile dementia is an optionally occurring disease requiring an endogenous component for its manifestation. The psychic peculiarities occurring in the course of normal aging result mainly from environmental factors (i.e. psychic and social injuries). They need multidimentional treatment.

Adjustment Disorders↗
PubMed1976

Sites of action of morphine involved in the development of physical dependence in rats. II. Morphine withdrawal precipitated by application of morphine antagonists into restricted parts of the ventricular system and by microinjection into various brain areas.

Morphine withdrawal was precipitated by injection of various morphine antagonists into restricted parts of the ventricular system or by microinjection of levallorphan into specific brain areas of rats made dependent on morphine by repeated pellet implantation. When the antagonists could spread only within the lateral ventricles and the 3rd ventricle, a weak withdrawal syndrome was induced; by antagonist administration into the restricted 4th ventricle, however, strong withdrawal signs like jumping were elicited even at small dosages. In microinjection experiments, structures in the midbrain and the lower brain stem proved to be the most sensitive to antagonist action. Although microinjections into thalamic nuclei also had some effect, it could not be excluded that the effects were due to uncontrolled spreading of the drug. This became especially clear from experiments with tritium-labeled levallorphan. It is concluded that brain structures located in the anterior parts of the floor of the 4th ventricle and/or caudal parts of the periaqueductal gray matter are important sites of action for the development of physical dependence on morphine.

Animals↗
PubMed1976

Acute rhino-orbito-cerebral mucormycosis.

Report of the typical clinical course and pathological findings in acute rhino-orbito-cerebral mucormycosis following diabetic coma. Invasion of orbital nerves by the fungus with neural and perineural changes may contribute to the neuroophthalmological symptoms in this disease besides the predilection for blood vessels with consequent thrombosis.

Acute Disease↗