Biomedical subjects

M Dambska

Publications and source records attributed to M Dambska.

At least 19 recordsLinked to original sources

PubMed1996

Different developmental rates of selected brain structures in humans.

Various rates of development are characteristic for particular structures of the human central nervous system (CNS). The differences of the maturing brain stem and telencephalon are evident in a routine neuropathological examination. The fetal and postnatal archi- and neocortex also reveals uneven levels of maturation. In order to precisely describe those differences in humans we performed a morphological and morphometric study on the dorsal vagal nucleus of the medulla oblongata, on Ammon's horn and on neocortex from midgestation to the 18th postnatal month. The numerical density of neurones, cell perikarya and nuclear cross-sectional area, and the ratio of nucleus to perikaryon area were measured. The results demonstrate a development-dependent decrease in cell density and progressive differentiation of neurones according to their changing size. They express a process of maturation which differs in rate across the CNS structures examined.

Brain↗

PubMed1996

Migration disorders leading to a wide spectrum of brain malformations in a case with multiorganic dysgeneses: A new syndrome?

A case of a preterm infant who died with multiorgan, mainly cerebro-oculo-cutaneous malformations is presented. The brain dysgenesias consist of early disturbances of neuronal migration. They result on appearance of nodular subcortical heterotopias, cortical anomalies including pachy- and polymicrogyria and focal intrusion of numerous abnormally migrating nerve cells into leptomeninges. A various degree of nerve and glial cell maturity was observed within heterotopic tissue. The other malformations include eye, skin and internal organs anomalies. Similarities and differences between our case and another previously described cases were discussed but it seems difficult to include the analysed case into one of the known syndromes.

Brain↗

PubMed1995

The features of peripheral nerve lesions in young and adult rabbits after vincristine administration.

The comparison of neuropathological picture of vincristine induced neuropathy immediately after the end of its administration and after three months of survival was performed. The adult rabbits and six litters of newborns received vincristine once a week in increasing doses 0.05-0.25 mg/kg of body weight. The early changes consisted in degeneration of axons and myelin sheaths and lesions of the Schwann cells. The features of changes allow to suspect that vincristine may induce, in addition to the well known primary axonal damage, a toxic effect on the Schwann cells with secondary damage of myelin sheaths. The changes were more severe in adults than in young animals. The observations after three months of survival allow to think that the administered doses of vincristine did not impede the improvement when treatment was interrupted.

Age Factors↗

PubMed1995

The vascularization of the developing human brain.

The principal rules of vascularization of developing central nervous system are presented. The angiogenesis as a mechanism of cerebral vessels formation was explained. The time of epiparenchymal plexus formation and penetration of endothelial channels into nervous tissue was reviewed evidentiating the correlation between the development of brain structures and their vascularization. Particular attention was devoted to the problem of formation and maturation of vessels within cerebral hemispheres, the rates of blood supply and drainage of their structures.

Blood-Brain Barrier↗

PubMed1995

Vascular malformations associated with other congenital anomalies of the central nervous system: coexistence and possible causal relations.

Two cases of vascular malformations coexisting with other congenital defects of the central nervous system (CNS) are presented here. The first patient was a 14-year-old girl mentally retarded who demonstrated seizures and balance disturbances with onset in early infancy. The neuropathological examination revealed vascular malformations in the pons, diastematomyelia (triple central canal) in the sacral spinal cord and palleocerebellar granular layer dysplasia. The second patient was a 10-year-old boy hospitalized because of purulent dermatitis who suddenly developed recurrent generalized and focal motor seizures. The neuropathological examination disclosed multiple capillary teleangiectases with focal anomalies within cerebral cortex of the frontal and parietal lobes. The relations between several developmental anomalies in the CNS and possible causal relation between such malformations are discussed.

Abnormalities, Multiple↗

PubMed1995

Neurofibromatosis type 2. Case report.

A case of a 24-year-old woman with peripheral paresis of the facial nerve, balance disturbance, hearing loss and epileptic seizures for many years is presented. At time of admission to hospital cerebral magnetic resonance imaging (MRI) showed several large tumors situated supra- and infratentorially. Histological examination of the operated tumors revealed bilateral acoustic schwannomas in the cerebellopontine angles and mixed meningioma in the others. The patient was diagnosed as neurofibromatosis type 2 (NF2) according to clinical criteria for neurofibromatoses. Several months after the last operation, she exhibited weakness of all extremities. On spinal MRI an intramedullary tumor in the cervical region and additional focal lesions along central canal were found. Surgical therapy was not performed because of clinical improvement after dexamethasone treatment and location of lesion in cervical medulla. Our case confirms frequently occurring lack of neurocutaneous changes and late appearance of significant neurological symptoms in NF2.

Adult↗

PubMed1995

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↗

PubMed1994

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↗

PubMed1994

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↗

PubMed1994

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↗

PubMed1993

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↗

PubMed1993

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↗

PubMed1992

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↗

PubMed1992

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↗

PubMed1992

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↗

PubMed1992

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↗

PubMed1992

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↗

PubMed1990

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↗