Developmental immunohistochemistry of catalase in the human brain.

The immunohistochemical studies on a peroxisomal enzyme, catalase, were done on brains from human fetuses to adults. The catalase-positive neurons appeared in the basal ganglia, thalamus and cerebellum at 27-28 weeks of gestation, and in the frontal cortex at 35 weeks. They then increased in number with gestational age. The extent of immunopositive staining increased with enlargement of perikaryonal size. However, the extent gradually decreased with postnatal age. On the other hand, catalase-positive glia appeared in the deep white matter at 31-32 weeks of gestation, their appearance shifting from the deep to the superficial white matter with increasing age. These results suggest that peroxisomes are closely related to neuronal growth and myelinogenesis in the human brain during development.

Relationship between periventricular hemorrhage, leukomalacia and brainstem lesions in prematurely born infants.

The brain pathology in very prematurely born infants with intraventricular hemorrhage (IVH) was studied particularly as to the severity and site of the complicated brain lesions responsible for the prognosis. A high frequency of leukomalacia, pontosubicular necrosis and/or olivocerebellar neuronal loss was found in the cases of IVH, and these non-hemorrhagic brain lesions showed an increasing frequency with the grade of IVH. However, there was marked reduction of IVH, periventricular leukomalacia and, in particular, brainstem lesions in prematurely born cases of sudden infant death. These IVH and associated conditions have different pathogenesis, but factors responsible for their occurrence may be present together in each case.

Continuous comparison of cerebral blood flow velocity and volume on hypoxia.

Cerebral blood flow velocity (CBFV) in the basilar artery, monitored by Doppler sonography, and cerebral blood flow (CBF) in the parietal cortex, monitored by Laser Doppler flowmetry, were continuously recorded and compared during and after hypoxic loading with nitrogen (N2) or carbon dioxide (CO2). On severe hypoxic loading (10% O2) of N2, CBFV and CBF increased with an increase in blood pressure (BP). On the other hand, with 18% and 15% O2 with CO2, CBFV and CBF increased with BP. However, there was a difference between CBF and CBFV in the recovery stage. CBF continued to be elevated for a long time, while CBFV rapidly normalized after loading. With 10% O2 with CO2, CBFV, CBF and BP decreased at first, and then increased during loading. Also, the difference between CBF and CBFV in the recovery stage being more definite. Thus, on continuous measurement, CBFV shows similar changes to CBF in response to hypoxia. However, CBFV shows different changes from CBF in association with dilatation or constriction of cerebral vessels. Resistance index (RI) shows different changes and have a different significance from CBF and CBFV.

Cortical cytoarchitectural and immunohistochemical studies on Zellweger syndrome.

In two cases of Zellweger syndrome, Golgi studies revealed an irregular neuronal arrangement, the presence of immature neurons, poor dendritic arborization and poor spine development, all of which suggest abnormal morphogenesis and delayed maturation. In immunohistochemical studies with antisera against human catalase, negative staining of neurons suggested a decrease of catalase due to defects of microperoxisomes, and positive staining of myelination glia only in the internal capsule may have been related to delayed myelination. Abnormal peroxisomal membrane or its related metabolites may cause a migration disorder in intrauterine development and myelination disturbance in perinatal maturation.

Response on near-infrared spectroscopy and of cerebral blood flow to hypoxemia induced by N2 and CO2 in young rabbits.

Cerebral blood oxyhemoglobin (HbO2), deoxyhemoglobin (HbR) and total hemoglobin (Hb) were examined in N2 and CO2 induced hypoxemia by near-infrared spectroscopy and compared with CBF examined by the H2 clearance method. HbO2 and HbR changed more sensitively than total Hb, reflecting the blood volume. Low CO2-loading showed marked increase in CBF with little change of blood volume, and higher CO2-induced hypoxemia was less increased and followed by a crossed after-reaction, probably because of persistent arterial dilatation due to the marked hypercarbia and acidosis. Neck venous compression showed a specific pattern of increased total Hb and HbR with little change in CBF. Thus, for near-infrared spectroscopy the intracranial blood volume may be affected mainly by arterial dilatation with an increase in CBF and venous dilatation with congestion. And Hb fractions of HbO2 and HbR may be influenced by cerebral blood oxygenation as well as the arteriovenous blood volume.

Cerebral venous thrombosis associated with recurrent epilepsy-like attacks.

A 9-year-old girl with recurrent episodes of unconsciousness, with or without convulsions, was reported. The episodes, which have been observed 9 times over the last 6 years, were characterized by generalized or hemi-convulsions, associated features of headache and vomiting, disturbance of consciousness lasting for a few days, slow activity on EEG continuing for a few weeks after the episodes and no prophylactic effect of anticonvulsants. Repeated EEG examinations revealed no epileptic discharges. Cerebral angiography showed corkscrew-like veins in the frontal region. Cerebral venous thrombosis is strongly suggested as the underlying cause of her episodes.

Development of myelination in the human fetal and infant cerebrum: a myelin basic protein immunohistochemical study.

The early development of myelination was studied by means of myelin basic protein (MBP) and luxol fast blue (LFB) stainings of large sections of the cerebral hemispheres. Myelination first occurs in the globus pallidus, pallidothalamic fibers of the posterior internal capsule and the thalamus at 25 weeks, which may be related to the cellular maturation in the globus pallidus and thalamus. Then myelination is observed in the striatum, and precentral and postcentral gyri at 35 weeks, and the anterior internal capsule and optic radiation at 37 weeks. Immunoreactivity with MBP is observed earlier and more strongly in the early myelination period than that with LFB. Thus, MBP may play an important role in myelination and its delay. The macroscopic positivity as to MBP as well as LFB staining may be related to the development of high signal intensity observed in a T1-weighted magnetic resonance imaging, which was observed 1 to 3 months after the first microscopic appearance of myelin.

Immunohistochemistry of superoxide dismutase-1 in developing human brain.

The developmental changes in superoxide dismutase (SOD)-1 were studied in brains ranging in age from human fetuses to adults by immunohistochemistry. SOD-positive neurons and glial cells appeared with maturation in each region, and increased progressively with gestational and postnatal age. This phenomenon implies a relationship between SOD-1 gene expression and the anti-oxidant defence mechanism in developing neurons and glia.

Immunohistochemical study of the vasculature in the developing brain.

In this study, the developmental proliferation of human brain vessels, from the fetal to the adult stage, was analyzed by immunohistochemical methods using antitype IV collagen, antilaminin, and antifibronectin antibodies. Examination of the frontal lobe indicates that these antibodies bind to the vessels, both arteries and veins. During cortical angiogenesis, the density and diameter of vessels increase rapidly from about 26 weeks gestation and peak at 35 weeks; after 35 weeks, the density and diameter of vessels are the same as those in adult brain. The white matter demonstrates no major changes in vessel density, although the pattern of the changes in vessel diameter resembles that of the cortex. Small immunopositive spots suggesting neovascularization reveal the same developmental tendency as the density of vessels in the cortex and white matter; therefore, it appears that neovascularization in the fetal brain during development is more rapid than cortical expansion and is equal to the growth of white matter. Neovascularization may be closely related to normal brain development and may play an undefined role in perinatal cerebrovascular insults.

Infantile subcortical leukohypodensity demonstrated by computed tomography.

We reviewed the computed tomography scans of 126 term infants, ages 1-6 months; leukohypodensity was found just under the cerebral cortex (subcortical leukohypodensity [SLD]) in 3 infants (2.4%) at 1-3 months of age. On subsequent computed tomography at over 4 months of age, SLD had disappeared and anterior horn predominant dilatation of the lateral ventricles had appeared. Only 1 patient with a distinct SLD had a poor neurodevelopmental outcome: spastic diplegia. SLD in our patients is believed to be closely related to subcortical leukomalacia because of the similar location and age distribution. Transient SLD may be a mild form of cystic SLD which would require careful computed tomography follow-up examination in early infancy.

Joubert syndrome associated with unilateral ptosis and Leber congenital amaurosis.

Two siblings are described with clinical features of Joubert syndrome associated with unilateral ptosis, severe visual disturbances with normal appearing fundi, and an occipital meningocele; one child also had polydactyly. Neither child manifested responses to electroretinography and one did not manifest visual evoked potentials. The siblings were considered to have characteristics of Leber congenital amaurosis and Joubert syndrome as well as unilateral ptosis. The presence of these findings in siblings suggests a genetic basis for their disease. Careful investigations should be conducted on infants with dysplasia of the cerebellar vermis, including tests for respiratory irregularities, retinal abnormalities, and renal abnormalities to further clarify the interrelationships of these conditions.

Morphological study of the brainstem in Fukuyama type congenital muscular dystrophy.

We have observed sudden clinical death due to Fukuyama-type congenital muscular dystrophy (FCMD). In FCMD, brain abnormalities, such as polymicrogyria, leptomeningeal neuroglial heterotopia and abnormal course of the corticospinal tracts, are well known. We investigated the brainstem of 10 FCMD and 7 control cases. Among the control cases, 5 with Duchenne type muscular dystrophy died of heart failure and 2 died accidental death. In the brainstem, the catecholaminergic neurons characterized by reaction with antiserum to tyrosin hydroxylase showed notable reduction in the reticular formation, vagal nuclei, and nucleus tractus solitarius. Delays or aberrations of neural control may contribute to the pathogenesis of sudden infant death syndrome, and medullary gliosis occurs in the reticular formation of sudden infant death syndrome. The pathogenesis of neurons in the brainstem in FCMD may be similar to that in sudden infant death syndrome. These findings suggest neuronal dysfunction in the brainstem and may be related to respiratory, circulatory, or sleep-wake regulation disorders.

Structure in lissencephaly determined by immunohistochemical staining.

The brains of patients with lissencephaly were examined by peroxidase-antiperoxidase immunohistochemical staining of synaptophysin, myelin basic protein, and glial fibrillary acidic protein. In contrast to the normal cortical pattern, the cortex, with a smooth surface, demonstrated quite different staining patterns in the molecular, superficial cellular, sparsely cellular, and deep cellular layers. The molecular layer was abnormally positive with synaptophysin staining. The superficial cellular layer was also diffusely stained for synaptophysin; there was a positive reaction in the linearly arranged myelin sheaths. The sparsely cellular layer revealed less staining for synaptophysin, but was perivascularly positive for glial fibrillary acidic protein. In the deep cellular layer, synaptophysin staining had multiple neuronal columns and myelin basic protein-staining had a reticular pattern around neuronal columns. These results suggest that the sparsely cellular layer may correspond to the molecular layer and white matter in normal brain; neurons with forming myelin sheaths in the superficial cellular layer regularly penetrate the surface of the molecular layer, forming arrested cortical columns in the deep cellular layer.

Clinicopathologic studies on leptomeningeal glioneuronal heterotopia in congenital anomalies.

Leptomeningeal glioneuronal heterotopia was observed in 40 of 129 autopsied infants (31%). It was present in 49% of patients who had congenital anomalies in general and in 65% of patients who had central nervous system malformations. Most of the leptomeningeal glioneuronal heterotopias appeared in the base of the brain (62.5%), midbrain (40%), frontal lobe (37%), and pons (35%). Leptomeningeal glioneuronal heterotopia is closely related to migration disorders on the basis of frequent association with polymicrogyria or neuronal heterotopias.

Developmental change in type VI collagen in human cerebral vessels.

Vascular development in the human brain was studied by immunohistochemistry using an anti-type VI collagen antibody. Positive vessels were evident from an early gestational age in the meninges, from 21 weeks gestation in the basal ganglia and deep white matter, and from 38 weeks gestation in the cerebral cortex and superficial white matter; however, type VI collagen never appeared in the subependymal germinal layer. The absent or scarce type VI collagen in the subependymal germinal layer may be one of the important factors of subependymal/intraventricular/periventricular hemorrhage in premature neonates. The earlier appearance of positive vessels in the deep white matter than in the cortex and superficial white matter suggests that the medullary vein develops earlier than the cortical and subcortical veins and arteries. These characteristics of the developing vascular structure may be one cause of perinatal brain damage.

Varicella with delayed hemiplegia.

We report 4 children who developed acute hemiplegia 7 weeks to 4 months after varicella infection. In 2 patients, carotid angiography demonstrated segmental narrowing and occlusion of the middle cerebral artery. Their clinical and angiographic features were similar to those associated with contralateral hemiplegia after herpes zoster ophthalmicus, the pathogenesis of which comprises cerebral angiitis due to varicella zoster viral infection. We believe that our patients had the same pathogenesis. In a survey of infectious diseases in our region, the frequency of varicella with delayed hemiparesis was roughly 1:6,500 varicella patients.

Monitoring of immature rabbit brain during hypoxia with near-infrared spectroscopy.

Continuous monitoring of the cerebral blood flow, oxyhemoglobin, deoxyhemoglobin, total hemoglobin, oxidized cytochrome a, a3, and tissue pH during prolonged CO2 or N2 loading in 2-week-old rabbits was performed by near-infrared spectroscopy, the thermocouple method, and a tissue pH meter. Near-infrared spectroscopy demonstrated decreases in oxyhemoglobin and oxidized cytochrome a, a3 and increases in deoxyhemoglobin and total hemoglobin in the early stage within 5 min, which gradually lessened with time on both 10% concentration of inspired O2 with CO2 and N2. CBF increased with venous retention in the early stage and then slowly decreased in parallel with blood pressure and oxidized cytochrome a, a3 on abolition of autoregulation. These changes were more remarkable during the 10% concentration of inspired O2 with CO2 than N2 which may be caused by marked acidosis and hypotension associated with hypercarbia. Oxidized cytochrome a, a3, however, demonstrated a gradual decrease in 10% concentration of inspired O2 with N2 rather than CO2; therefore, the continuous monitorings demonstrated hemodynamic and oxygenation changes despite the same extent of prolonged hypoxic loading. These changes in prolonged hypoxic conditions may occur in human intrapartum asphyxia which develops into postnatal hypoxic-ischemic encephalopathy.

Cerebellar leptomeningeal astroglial heterotopia in neurofibromatosis type 1.

Leptomeningeal astroglial heterotopia (LAH) was found in the cerebellum of 2 patients with neurofibromatosis type 1 (NF 1). This LAH was clearly and widely demonstrated with glial fibrillary acidic protein (GFAP) immunohistochemistry and was connected with parenchymal astroglial fibers. These findings suggest that NF 1 involves the dysplasia or overgrowth of astrocytes in the cerebellar leptomeninges.

Scanning electron microscopic observations on muscle cells of experimental mitochondrial myopathy produced by 2, 4-dinitrophenol.

The morphological changes of the skeletal muscle cells of the rat experimental myopathy induced by 2, 4-dinitrophenol were examined by scanning electron microscopy in comparison with the ultrastructure of normal muscle cells. Specimens were prepared by the Aldehyde-Osmium-DMSO-Osmium method which permits the three-dimensional demonstration of intracellular structures under SEM. In the specimen prepared by the method, myofibrils having been completely dissolved, intracellular membranous structures such as the sarcoplasmic reticulum, T-tubules and mitochondria were clearly demonstrated in three dimensions. In the experimental mitochondrial myopathy, large accumulations of mitochondria were observed at the subsarcolemmal region. Mitochondria in the perinuclear and intermyofibrillar region showed swelling and occasionally accompanied abnormal concentric cristae. The sarcoplasmic reticulum which showed regular network in normal muscle cells entirely disappeared in the mitochondrial myopathy. Although the mitochondrial changes obtained in this study were almost identical to those previously reported by transmission electron microscopy, the changes in the sarcoplasmic reticulum have not been described in previous works.

[Usefulness of ultrasonography and transcranial Doppler flowmetry in evaluation of infantile bacterial meningitis].

A 40-day-old girl with B-group streptococcal meningitis was examined with ultrasonography (US) and transcranial Doppler flowmeter. Transfontanelle US with a 7.5 MHz probe showed a dilatation of the extracerebral space (ECS). The flow velocity in the middle cerebral artery increased remarkably in the acute phase, and thereafter returned to normal. The superficial arterial velocity on the left side could not be recorded in the period of fluid collection in the left ECS. These two methods are useful procedures in the evaluation of infantile bacterial meningitis and its complications.