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Biomedical subjects

M Dambska

Publications and source records attributed to M Dambska.

At least 37 records · Page 2Linked to original sources

Correlations between clinical and neuropathological diagnosis of cortical anomalies in developmentally disabled children.

The capabilities and limitations of clinical diagnoses, particularly brain imaging of cortical anomalies, in developmentally disabled children are reviewed. Some aspects of diagnostic problems in generalized cortical dysgeneses, like lissencephaly type I and II, subcortical heterotopias, generalized polymicrogyria, or focal cortical anomalies and primary micrencephalies, are discussed.

Brain Diseases↗

Neuropathological variants of cystic encephalopathy in infants.

The aim of our study was to present six cases with cystic changes within the white matter in infant brains and discuss the variants of this type of neuropathological lesions of the developing brain. Two of them exhibited the changes characteristic for cystic leucoencephalopathy. To the others with moderate involvement of gray structures, the term multicystic encephalopathy seems to be more appropriate. The clinical course and the neuropathological features of changes allow to consider them as syndromes characteristic for a given period of brain maturation.

Astrocytes↗

The insular claustrum in the methylazoxymethanol acetate (MAM) treated rats shows two different populations of neurons.

Methylazoxymethanol acetate (MAM) is a substance that inhibits migration of neurons in the embryonic brain. After intraperitoneal injection of two different doses of MAM to pregnant rats, microcephaly with or without complete development of the cerebral cortex was observed in every litter. High MAM doses (30 mg/kg) resulted in the lack of superficial layers (II-IV) of the cerebral cortex when the deep layers (V, VI) were seen. The claustrum was present but composed of loosely packed, medium-size, triangular or fusiform neurons with anarchic oriented long axes. After administration of low MAM doses (14 mg/kg) two different parts (medial and lateral) of the insular claustrum were observed. Our results suggest that neurons of the insular claustrum create two different subpopulations of cells, which were similar to that observed in primitive insectivore (e.g., hedgehog), but fuse in development.

Animals↗

Multinucleated giant cells in areas of the brain stem necrosis after cardiac arrest in two infants.

A rare type of cellular reaction in the brain stem of two infants with cardiac arrest encephalopathy is presented. After cardiac arrest both newborns were resuscitated and put on artificial ventilation. Their survival time amounted to 16 and 18 days, respectively, in a deep coma with areflexia. At the postmortem examination a widespread hemispheric necrosis of the gray and white matter was observed as well as symmetrical necrosis of the tegmental part of the brain stem extending from the midbrain up to medulla. Striking proliferation of blood vessels and large number of multinucleated giant cells originating from monocyte/macrophage lineage was found in the areas of the brain stem necrosis. No evidence of inflammatory process was found. It seems that giant cells appeared as local reaction on disintegration of maturing structures.

Autopsy↗

Disturbances of cortical development.

The development processes coinciding in formation of cerebral cortex were presented. On this background may arise the cortical developmental abnormalities. The review of principal cortical malformations include the 1) agyria-pachygyria - lissencephaly type I, 2) polymicrogyria, 3) disorganized cortical structure - lissencephaly type II, 4) minor cortical developmental anomalies and 5) other cortical dysplasia syndromes. It will help to reconstruct the pathomechanism of cortical abnormal development from early occurring primary errors to late changes in which coincide necrotic lesions. The presented material illustrate the role of time of occurrence and intensity of damage in final result of pathologic developmental processes.

Cerebral Cortex↗

Cerebral infarcts in newborns and infants with cyanotic cardiac anomalies.

Neuropathological examination of six brains of newborns and infants who died in the course of congenital cyanotic cardiac anomalies showed focal brain lesions. The material included five cases from two weeks to two months of age, and one two-year-old infant. In two of them, the periventricular ischemic infarcts were found, in one multifocal encephalomalacia due to multiple vascular occlusions, and in three the necrotic foci corresponded to the supply of large cerebral arteries. The character and topography of severe brain lesions, particularly within the hemispheric white matter, were clearly influenced by the immaturity of the cerebral structures.

Astrocytes↗

Perinatal damage of brain stem depending on the maturity of its structures.

The aim of this study was to discuss the interaction between the maturation of the brain stem and its susceptibility to perinatal lesion. Many observations indicate that the last months of pregnancy and the perinatal period are the time of intensive maturation of these structures. Lesions of the brain stem were many times found after acute anoxia as well as after chronic asphyxia during this period. This indicates the importance of prevention of the pathology of pregnancy. Occurring in the last trimester of gestation it can induce damage of brain stem centers important for the fetus to survive the stress of birth and adaptation for individual life.

Asphyxia Neonatorum↗

Astrogliosis in the temporal lobe of newborn infants who died in the perinatal period.

The normal distribution of astrocytes in the temporal lobe of the newborn and that occurring as consequence of perinatal pathology was compared. The astrocytes were revealed by immunohistochemical visualization of glial fibrillary acidic protein (GFAP). The intensity of positive reaction correlates well with the maturation of various white structures. In the group with hypoxic encephalopathy the GFAP-positive reaction was clearly related to the observed neuropathological changes. Intensive reaction in the area of U-fibers confirmed the susceptibility of this region to hypoxic damage. The presence of GFAP-positive cells within Ammon's horn indicates that the degree of reaction depends on the intensity and duration of the lesions.

Astrocytes↗

Damage of maturing brain in the course of toxoplasmic encephalitis.

The aim of the study is to present the damaging influence of toxoplasmic encephalitis on newborn brains. The material consisted of six cases of toxoplasmosis who died during the first months of life. The neuropathological picture indicated indirectly the mechanism of spread of the inflammatory-necrotic process. In the first stage of pathologic process intensive inflammatory infiltrations in the periventricular white matter were seen. In the next stage the necrotic changes involved the majority of the hemispheric white matter. Further development of the disease transformed the brain hemispheres into thin-walled sacs composed of meninges and remnants of the nervous system. Finally, the inflammatory process resulted in hydranencephaly. Proliferation of subependymal glia evident in all cases and blocking the pathways of the cerebro-spinal fluid circulation, may have played a role in this process.

Brain↗

Effect of selected cytostatic drugs administration on the brain of young rabbits.

The aim of the study was to compare the effect of two selected cytostatic drugs (cyclophosphamide and vincristine) on the brain of young rabbits. The experimental models were similar to clinical administration of the examined drugs. Cyclophosphamide was given orally from the 5 to the 16th day of life and vincristine in a single intraperitoneal injection on the 8th day of life. Despite the assumed poor penetration of both drugs through the blood-brain barrier, both drugs induced changes in perivascular astrocytes. Other structural elements of the CNS exhibited lesions characteristic for the given drug: proliferation of endoplasmic membranes after cyclophosphamide administration and destruction of microtubules with proliferation of microfilaments after vincristine application.

Animals↗

The effect of some exogenous factors on the formation of intranuclear membranaceus inclusions in the nerve cells.

The intranuclear membranaceus inclusions (IMI) appear as encapsulated irregular vacuoles surrounded by a single, rarely double, membrane. The vacuoles include floccular, fine granular content or they are translucent. They were found in neurones of particularly old or very young laboratory animals. Our studies concerning various types of intoxications and ischemia allowed to find relatively large number of such inclusions in laboratory animals. We observed them in four experimental models: (1) cyclo-phosphamide (an alkylating drug) and (2) dichlorvos (phosphoroorganic pesticide) given orally to rabbits, (3) complete ischemia also in rabbits and (4) vincristine (an antimitotic drug) given parenteraly to rats. The IMI were found much more frequently in experimental animals than in controls. We can conclude that intranuclear membranaceus inclusions do not appear to be pathognomonic for any particular etiologic factor, but this factor may influence and distort the homeostasis within nucleus.

Animals↗

Myelination as a parameter of normal and retarded brain maturation.

In this study a comparison of the myelination rate in humans in normal and pathologic conditions was made. The progress of myelination was examined on slides stained by the Klüver-Barrera method and evaluated as to four degrees. The prenatal myelination in the brain stem in a group of newborns who died of pregnancy pathology was correlated with normal brain stem myelination. Retardation of myelination by 2 to 10 weeks was found in cases with gestosis and diabetes in anamnesia. The myelin sheath formation in a group of children who died during the first three years of life after severe chronic diseases neoplastic and congenital heart failure was compared with the normal rate of postnatal myelination of the temporal lobe. The myelination process was evidently retarded by 2 to 20 months. The observations presented in this paper allowed the conclusion that pathologic conditions occurring in the maturing human may cause retarded maturation of myelin sheath.

Brain Diseases↗

[Effect of chemotherapy for neoplasms on the central nervous system in children].

Lesions to the central nervous system were studied in twenty children, aged 1-12 years decreased because of neoplastic disease of internal organs and treated with cytostatics. The young age of the patients allowed to attribute the observed changes to this disease. Several damaging factors occurring during its course were analysed. Lesions were found in cerebral and cerebellar cortex; walls of blood vessels were also damaged. We may conclude that chemotherapy prolonging the survival of children allowed the development of encephalopathy and modified its picture.

Antineoplastic Combined Chemotherapy Protocols↗

Some aspects of brain morphology of the chronic cat and kitten preparations with brain stem transected at the pretrigeminal level.

In two adult cats and in three kittens aged from 8 to 11 days the brain stem was transected at the pretrigeminal level. The preparations were maintained from 7 to 79 days and processed histologically together with nonoperated controls. In kitten preparations brain was underdeveloped as shown by less numerous secondary sulci on the surface of the cortex. However, both cat and kitten preparations showed similar retrograde and anterograde neuronal degeneration. They also showed a similar transneuronal degeneration apparent in an increased density of neurons and their shrinkage in several structures investigated in the isolated cerebrum and the lower brain stem. Thus in kitten preparations a direct effect of transection predominated that of brain development. In the adult preparations at the level of transection a great accumulation of macrophages was found and the scar was built with connective tissue. In contrast, in kittens the transection scar was well delineated and built by astrocyte processes.

Aging↗

Early and late neuropathological changes in perinatal white matter damage.

Our material presents two patterns of white matter lesions in the brain of newborns dying with the clinical diagnosis of intrauterine or perinatal pathology: (1) classical periventricular ischemic infarction resulting in coagulative necrosis and (2) diffuse periventricular colliquative necrosis, in some cases involving the center of the cerebral convolutions. The majority of cases did not survive the first month of life. The cases with longer survival (up to six years) presented clinically with the syndrome of bilateral spastic cerebral palsy. Neuropathological examination showed dilation of the lateral ventricles, small cavities, and diffuse glial scars, not only in the periventricular white matter but also involving the axis of cerebral convolutions, as opposed to the relative sparing of cerebral cortex and other brain structures. These changes could be considered as evident or putative forms of a distinct type of perinatal brain damage.

Brain Stem↗

Spino-cerebellar degeneration with polyneuropathy associated with ceroid lipofuscinosis in one family.

There are several clinically distinct forms of neuronal ceroid lipofuscinosis whose presentation and pathology are usually homogeneous within families. Several atypical variants have also been reported. We have studied an inbred sibship in which neuronal ceroid lipofuscinosis appeared to present in two completely different ways. In the proband, the course was compatible with a somewhat atypical juvenile variant. Ataxia and spasticity started at 4.5 years, followed by blindness with optic atrophy, intractable seizures, dementia, and death at 14 years. Atypical features included areflexia, hypotonia, and ataxia. Electron microscopic studies of her skin and her rectal ganglion cells showed lucent, dense, and fingerprint inclusions that were also found in the central nervous system at autopsy. Her brother and sister developed difficulty walking at ages 8.5 and 10.5 years and are alive at 24 and 18 years. They presented with slowly progressive spinocerebellar degeneration with sensorimotor neuropathy without dementia, seizures, or visual impairment. Lysosomal enzymes and lipoprotein analysis were normal in all three siblings and their parents. Elevated dolichol in the urine and lucent, dense, and fingerprint inclusions in skin, cutaneous nerve, buffy coat lymphocytes in both siblings and in the sural nerve of the brother suggest that their disease may represent a novel phenotype of neuronal ceroid lipofuscinosis. While it is possible that two different recessive genes may be segregating in this consanguineous family, we cannot dismiss the possibility that variability of gene expression may account for the divergent phenotypes.

Adolescent↗