Hypertrophy of the cerebral white matter in hemimegalencephaly

We morphometrically measured the cut surface of the cerebral hemisphere and localized epidermal growth factor (EGF)-like immunoreactivity in 4 patients with hemimegalencephaly. On the affected side, the area of cerebral white matter was more than twice as large as that on the unaffected side, while the area of the cerebral cortex on the affected side was relatively small. EGF-like immunoreactivity was demonstrated in cortical neurons (4 of 4 patients) and glial cells (3 of 4 patients), notably in astrocytes. Significant enlargement of the cerebral white matter compared to the cerebral cortex and the expression of EGF-like molecules in astrocytes suggest excessive proliferation in the white matter with hemimegalencephaly and the possible relevance of EGF to these events.

Immunochemical and immunohistochemical localization of Bcl-x protein in the rat central nervous system

To explore the role of bcl-x in the regulation of cell death in the nervous system, we produced monoclonal antibodies against rat Bcl-xL protein, the major product of the rat bcl-x gene that inhibits apoptosis, and defined its distribution in rat neural tissues by immunochemical and immunohistochemical means. Western blotting of tissue homogenates identified the Bcl-x protein as two bands with molecular weights of about 29 and 31 kDa. The level of Bcl-x expression in the nervous system was high, being comparable to that in the hematolymphoid system, and higher in the fetal than in the adult brain. Subcellular fractionation studies localized Bcl-x to various subcellular compartments. In tissue culture, Bcl-x was produced by all the cell types examined, including neurons, astrocytes, oligodendrocytes and microglial cells. Immunohistochemistry revealed that Bcl-x immunoreactivity was more intense in the gray than in the white matter. In the fetal cerebral cortex, labeling was mostly confined to the neuronal perikarya, whereas in the more mature brain, the neuropil of the gray matter, as well as the glial cells in the white matter, was also stained.

Transient expression of apolipoprotein-E in neonates with pontosubicular neuron necrosis

An apolipoprotein-E (Apo-E) immunohistochemical study was performed on neonates with pontosubicular neuron necrosis (PSN), aged 38-42 weeks of gestation, and compared to findings for age-matched neonates without PSN. Apo-E was expressed in neurons in both the pontine nuclei and pyramidal layer of the hippocampus, as well as astrocytes of only the PSN cases. The immunoreactive neurons did not exhibit karyorrhexis and were found in neonates by the age of 6 days. Apo-E may be produced by astrocytes and taken up by neurons on membrane remodeling during early responses to cerebral hypoxic or ischemic insult in PSN neonates.

Sensory neuropeptides are not directly involved in bronchial hyperresponsiveness induced by interleukin-8 in guinea-pigs in vivo

BACKGROUND

Interleukin-8 (IL-8) has been shown to be a chemotactic factor for neutrophils, T-lymphocytes and eosinophils. Repeated intranasal administration of IL-8 enhances bronchial responsiveness to inhaled histamine in guinea-pigs. Neuropeptides which are released from C-fibre nerve-endings have been postulated to induce bronchial hyperresponsiveness through neurogenic inflammation.

OBJECTIVE

This study was conducted to examine whether sensory neuropeptides are involved in the IL-8-induced bronchial hyperresponsiveness.

METHODS

IL-8 at a dose of 5 micrograms/kg was administered intranasally to guinea-pigs twice a week for 3 weeks. One day after the last administration, animals were anesthetized and artificially ventilated through tracheal cannula, and lateral pressure at the tracheal cannula (Pao) was measured as an overall index of airway responses to increasing concentrations of inhaled histamine (25, 50, 100, and 200 micrograms/mL). A NK1 and NK2 dual antagonist FK224 (10 mg/kg), a selective NK1 antagonist FK888 (10 mg/kg) or vehicle was intravenously administered 10 min before measurement of bronchial responsiveness.

RESULTS

The IL-8 treatment significantly enhanced bronchial responsiveness to histamine (ANOVA P < 0.01). FK224 or FK888 did not alter the IL-8-induced bronchial hyperresponsiveness.

CONCLUSION

We conclude that repeated intranasal administration of IL-8 causes bronchial hyperresponsiveness (BHR) and that neuropeptides such as neurokinin A and substance P do not directly contribute to the development of BHR induced by IL-8.

[Chronic persistent coughing successfully treated with ozagrel]

A 25-year-old woman complained of coughing for over 8 weeks. The coughing was not relieved by a bronchodilator (beta 2-adrenoceptor agonist; clenbuterol), and anti-allergic agent (azelastine), or an inhaled corticosteroid. The thromboxane synthetase inhibitor ozagrel completely abolished her cough. In this case, thromboxane A2 may have contributed to the coughing.

Involvement of NK2 receptors rather than NK1 receptors in bronchial hyperresponsiveness induced by allergic reaction in guinea-pigs

1. In this study, the role of neuropeptides in antigen-induced bronchoconstriction and bronchial responsiveness in guinea-pigs was evaluated by use of phosphoramidon, the inhibitor of neutral endopeptidases (NEP), the NK1 receptor antagonist, FK888, and the dual NK1/NK2 receptor antagonist, FK224. The role of endogenous tachykinins in bronchial hyperresponsiveness induced by inhaled capsaicin was also observed with FK888 and FK224. 2. Allergic bronchoconstriction and bronchial responsiveness was evoked by inhalation of ovalbumin (OA), and increasing doses of methacholine were inhaled at 5-min intervals for 30 min after OA challenge in passively sensitized and artificially ventilated guinea-pigs. Animals were treated with a 30 s inhalation of phosphoramidon (10(-3)M) or saline 10 min before the OA challenge. FK888 (1.0 or 10 mg kg-1) or FK224 (1.0 or 10 mg kg-1) was administered intravenously 5 min before the OA challenge. 3. Treatment with phosphoramidon did not alter the increase in the lateral pressure at the tracheal tube (Pao) caused by OA inhalation or the increase in bronchial response to methacholine following the allergic reaction. Pretreatment with FK224 did not inhibit the increase in Pao after antigen provocation but did significantly inhibit antigen-induced bronchial hyperresponsiveness in a dose-dependent manner, while FK888 did not affect either allergic bronchoconstriction or post-allergic bronchial hyperresponsiveness. 4. Histamine, 25, 50, 100 or 200 micrograms ml-1 was inhaled for 20 s at 5-min intervals in non-sensitized guinea-pigs which were pretreated with inhalation of subthreshold dose of capsaicin (10(-7) M). FK888 or FK224, each at a dose of 0.1 or 1.0 mg kg-1, or vehicle was given to guinea-pigs intravenously 3 min before inhalation of capsaicin. The capsaicin inhalation significantly potentiated bronchial responsiveness to histamine, compared with control. The capsaicin-induced bronchial hyperresponsiveness was completely blocked by FK224 in a dose-dependent manner but not by FK888. 5. These results suggest that NK2 receptors rather than NK1 receptors may play an important role in bronchial hyperresponsiveness induced by antigen challenge as well as capsaicin while tachykinins do not play a primary role in the acute bronchospasm elicited by antigen challenge in passively sensitized guinea-pigs.

Neuronal and vascular pathology produced by verocytotoxin 2 in the rabbit central nervous system

To study the pathogenesis of the central nervous system (CNS) involvement associated with verocytotoxin-producing Escherichia coli infection, we developed an animal model by administering verocytotoxin 2 to rabbits either intravenously or intrathecally. After an interval of 2-9 days, the rabbits became paralyzed in a dose-dependent manner and in the absence of renal impairment. The minimal intravenous and intrathecal doses that produced these neurological signs were 250 and 0.4 ng/kg, respectively. After intravenous administration, most of the toxin was cleared from the serum within 24 h, with concomitant transition of a small amount into the cerebrospinal fluid. Pathological examination revealed that neurons in various CNS regions showed atrophy, cytoplasmic hyperchromasia and nuclear pyknosis as early as 6 h after administration. The distribution of affected neurons was constant and irrespective of the route of administration. Abnormalities of the blood vessels, such as the thickening of arterioles walls, were noted from 2 days after administration. The vascular lesions became more prominent after the intrathecal injection, which caused thrombosis and multiple infarction. Selective deposition of the toxin on the vessel walls was demonstrated immunohistochemically. Thus, the pathological manifestations of verocytotoxin 2 neurotoxicity consisted essentially of two types of lesions, early neuronal and late vascular, both of which might have developed under the influence of the toxin that had entered the CNS by crossing or circumventing the blood-brain barrier.

High expression of Bcl-x protein in the developing human cerebellar cortex

The gene bcl-x, which is related to a bcl-2, regulates programmed cell death. bcl-x may function in the development of the nervous system. We raised a polyclonal antibody against human Bcl-x protein, and investigated its distribution in the developing human cerebellum. Western blotting revealed that Bcl-x expression in the cerebellum is higher in the fetal, than in the postnatal period. Immunohistochemical studies of fetal brains localized intense Bcl-x immunoreactivity in the granule cell processes at 13-22 gestational weeks and in the Purkinje cell bodies at 24-38 weeks. The immunoreactivity decreased after birth, but was retained in the Purkinje cells at a low level until adulthood. These results suggested that Bcl-x expression in the cerebellum is developmentally regulated and involved specifically in the development of neuronal subpopulations.

[Classification and pathogenesis of cerebral cortical malformations]

Cerebral cortical malformation is now diagnosed by neuroimagings, and important as a cause of developmental disorder or epilepsy. The classification of cortical malformations was tried from developmental aspect, and agyria in Miller-Dieker syndrome and polymicrogyria in Fukuyama-type congenital muscular dystrophy were compared on their pathogeneses. Unilateral hemimegalencephaly and focal cortical dysplasia were reviewed on literatures.

A tyrosine kinase-like molecule is localized in the nuclear membrane of neurons: hippocampal behavior under stress

Protein tyrosine kinases play important roles in the development of the mammalian nervous system during embryogenesis and in the maintenance of function of the adult brain. Using a semi-nested PCR technique based on a short amino acid motif of protein tyrosine kinases, we isolated a human genomic DNA encoding a peptide whose sequence was related to known mammalian protein tyrosine kinases. The expression was examined by Northern blot analysis, and transcripts were detected almost exclusively in the brain. The corresponding cDNA was sequenced, and it was revealed that the gene designated as byk coded for a receptor-like molecule with a motif of protein tyrosine kinase. Immunohistochemical analysis demonstrated that the Byk protein was expressed in neurons and was located in the nuclear envelope. To understand the physiological significance of the Byk protein, we investigated the behavior of this molecule in the hippocampus after ischemia. Byk-like immunoreactivity disappeared from the neurons in the fields CA1 through CA3 and the dentate gyrus of the hippocampus following 20 min of ischemia. After recirculation of blood flow, neurons in the CA3 field and the dentate gyrus re-expressed Byk-like antigen but CA1 neurons did not. Interestingly, Byk-like immunoreactivity was detected in microglial cells and astrocytes in the CA1 field that were activated after ischemia. Byk could be a new tool to study the neuron-glia and glia-glia interactions.

Immunohistochemical expression of tumor necrosis factor alpha in neonatal leukomalacia

The expression of tumor necrosis factor alpha (TNF alpha) was examined in infants with leukomalacia by means of immunohistochemical methods with an antihuman TNF alpha monoclonal antibody. We studied 23 patients with neonatal leukomalacia, classified as having "focal," "widespread," or "diffuse" disease according to the distribution of the lesions, and 18 age-matched controls. TNF alpha immunoreactivity was positive in 19 of the 23 (83%) patients with leukomalacia, and in 7 of the 18 (39%) controls. TNF alpha was expressed mainly in glial cells in the deep white matter in both groups, and was most abundant around the necrotic foci in the focal group. TNF alpha immunoreactivity appeared earlier in patients with leukomalacia than in controls, being first detected at 25 and 29 weeks gestation, respectively. Immunofluorescence double-labeling revealed the TNF alpha -immunoreactive cells were Ricinus communis agglutinin-1 (RCA-1)-positive microglial cells. Thus, our study revealed increasing expression of TNF alpha in the normally developing brain during the late fetal period, and overproduction of TNF alpha by microglial cells associated with the pathogenesis of neonatal leukomalacia.

Inhibition of HTLV-I induction and virus-induced syncytia formation by oligodeoxynucleotides

HTLV-I is an exogenous human retrovirus that is a causative agent of adult T cell leukemia (ATL). In addition to the structural genes (gag, pol and env), a gene termed pX is postulated to be associated with leukemogenesis in ATL. Since no effective chemotherapy is currently available, it is important to find suitable therapeutic means against ATL. Here, we tested the inhibitory effect of antisense oligodeoxynucleotides (ODNs) on HTLV-I infection in different systems. ODNs were synthesized with the phosphorothioate backbone targeted to either structural genes or transactivator genes. The phosphorothioate ODNs were found to have two distinct target sites to exert their effect on HTLV-I infection: 1) Several ODNs, including sense ODNs and random oligomers, blocked syncytium formation induced by HTLV-I at a concentration of 0.1 microM. Their inhibitory effect on syncytium formation seemed to be exerted in a nonantisense manner, most probably due to their interaction with the cell membrane. 2) Efficient suppression by ODNs of gag gene expression after chemical induction was observed in HTLV-I-transformed T cells in an antisense manner. In this suppression, tax-antisense ODN showed virtually complete inhibition of gag protein expression, but not RNA expression, at the concentration of 0.1 microM, whereas tax-sense ODN displayed a weak inhibitory effect. Our results suggest that the influence of the phosphorothioate compound should be considered from the aspect of two separated mechanisms of antiviral activity, the effects on early (viral adsorption) and late (translation) phase infection.

[MR imaging of colonic cancer with retrograde administration of contrast material containing ferric ammonium citrate]

MR imaging was performed with the retrograde administration of ferro-magnetic contrast material and air in 10 patients with rectosigmoid colon cancer. The border of the lesions was well demonstrated in spin echo images, and MR imaging yielded additional diagnostic information to that provided by barium enemas and CT scans in all cases. In conclusion, this type of contrast material seemed promising in the MRI diagnosis of rectal lesions.

[Effect of clarithromycin on symptoms and mucociliary transport in patients with sino-bronchial syndrome]

The effect of clarithromycin on symptoms and on mucociliary transport (as assessed by the saccharin test) were studied in 32 patients with sino-bronchial syndrome. Before treatment with clarithromycin, the nasal clearance time was significantly longer in these patients (70.3 +/- 64.7 min, mean +/- SD) than in control subjects (11.9 +/- 5.3 min, p < 0.001). By the end of 4 weeks of treatment with oral clarithromycin (400 mg/day), nasal clearance time in the patients had improved significantly (30.4 +/- 39.5 min, p < 0.001). Before clarithromycin therapy, bacteria were found in cultures of sputum from 15 patients. After clarithromycin therapy, bacteria were found in cultures of sputum from only 3 of those 15 patients. Cough frequency, volume of sputum, and dyspnea on exertion were significantly improved by clarithromycin therapy. These findings suggest that mucociliary transport is abnormal in patients with sino-bronchial syndrome, and that clarithromycin can be clinically useful in these patients.

Development of endothelial nitric oxide synthase in endothelial cells in the human cerebrum

We demonstrate the distribution and development of endothelial nitric oxide synthase (eNOS) immunoreactivity in vessels of the human brain. eNOS-positive endothelial cells were recognized in small vessels in the parenchyma of the cerebrum, as well as in the large arteries and veins in the leptomeninges. By 10-13 weeks of gestation, eNOS-positive endothelial cells had already appeared in the vessels of the leptomeninges and deep white matter. Immunoreactivity for eNOS was noted in most vessels at 14-17 weeks in the intermediate white matter, at 18-21 weeks in the cortex, and at 23-26 weeks in the subcortical white matter. Such differences in regional development may be responsible in part for the topographical predilection for hemorrhagic or hypoxic-ischemic lesions in the developing brain.

Developmental changes of epidermal growth factor-like immunoreactivity in the human fetal brain

We investigated the immunohistochemical localization of epidermal growth factor (EGF) in the developing human brain from 6 weeks of gestation to 3 months postpartum. EGF-like immunoreactivity varied in its localization and intensity according to the stage of development. At 10 - 20 weeks of gestation, EGF-like immunoreactivity appeared in proliferating and migrating cells in the cerebrum, disappeared thereafter, and appeared again in cortical neurons after 27 weeks of gestation. Astrocytes also showed EGF-like immunoreactivity from 27 weeks of gestation. These results suggest developmental regulation of EGF expression in the human brain, suggesting its physiological role in both neuronal and glial cells.

Neuronal localization of CD38 antigen in the human brain

CD38 is a lymphocyte differentiation antigen which is involved in the cyclic ADP-ribose-mediated second messenger system. We provide immunochemical and immunohistochemical evidence for the expression of CD38 in the adult human brain. We used six polyclonal antibodies against synthetic CD38 polypeptides, in addition to four monoclonal antibodies already available. Brain CD38 was detectable by Western blotting after immunoaffinity purification of the brain extracts. Immunoperoxidase staining localized CD38 immunoreactivity to the perikarya and dendrites of many neurons, such as the cerebellar Purkinje cells, implying that CD38 is involved in the signal transduction within the central nervous system neurons.

Lissencephaly gene product. Localization in the central nervous system and loss of immunoreactivity in Miller-Dieker syndrome

The Miller-Dieker syndrome, a disorder of neuronal migration, is caused by deletions of chromosome 17p13.3. Recently, a gene on 17p13.3, named LIS-1, was identified as the causative gene for this cerebral anomaly. Here we immunochemically and immunohistochemically localized the gene product, LIS-1 protein, among control normal subjects and patients with Miller-Dieker syndrome, using specific antibodies raised against synthetic peptide fragments of LIS-1 protein. Western blot analyses identified LIS-1 protein as a 45-kd, heparin-binding protein abundant in the cytosolic fraction. The protein was restricted to the central nervous system and detectable in brains of controls of all ages, from the early fetal to adult period. Immunostaining demonstrated the widespread distribution of LIS-1 protein in the brain and spinal cord of controls and a loss of immunoreactivity in individuals with Miller-Dieker syndrome. These results are consistent with the notion that a deficiency of LIS-1 protein is the direct cause of the brain malformation and that the protein plays a critical role in neuronal migration.

Cystic leukomalacia in the cerebellar folia of premature infants

Cystic necrosis in the cerebellar white matter was found in three premature infants. The necrosis was characteristically localized in the center of the white matter of the superficial cerebellar folia, sparing the overlying cortex. The patients were aged between 28 and 34 gestational weeks, and had a clinical history of severe systemic hypotension. Thus, cystic leukomalacia represents a characteristic brain lesion in premature infants which may be caused by cerebellar hypoperfusion.

Expression of beta-amyloid precursor protein in axons of periventricular leukomalacia brains

Human beta-amyloid precursor protein immunoreactivity was demonstrated in axonal swellings (spheroids) around periventricular leukomalacia (PVL) of neonates. Immunoreactive axons were found at the early, but not late stage of PVL. beta-Amyloid precursor protein immunoreactivity was homogeneous in damaged axons at the early stage of PVL manifesting microglial activation, concentrated at the center of axonal swellings at the subsequent stage manifesting astrogliosis, and undetectable at the terminal stage of cavitation or neovasculation. Immunostaining for beta-amyloid precursor protein was useful in localizing PVL lesions at their early stages.

Developmental changes of apolipoprotein E immunoreactivity in Down syndrome brains

The temporal profile of apolipoprotein-E (apo-E) expression was investigated immunohistochemically in the brains of Down syndrome patients and of normal controls. The number of apo-E immunoreactive astrocytes in the frontal cortex was larger in Down syndrome patients than in controls from 7 months to 24 years of age. It suggests that apo-E producing astrocytes in the early phase of pathological process lead to presenile dementia in Down syndrome patients. In contrast, the number in the white matter was smaller in Down syndrome patients from 28 gestational weeks to 5 years. Apo-E immunoreactive senile plaques were noted in Down syndrome brains from the age of 25 years, while APP immunoreactivity was first noted in senile plaques at the age of 32 years.

The prenatal age critical for the development of the pontosubicular necrosis

Pontosubicular neuronal necrosis is characterized by neuronal karyorrhexis, showing a peculiar distribution. In infants delivered at more than 29 gestational weeks (GW), neuronal karyorrhexis is restricted to the pons and subiculum, while in very premature infants (delivered at less than 28 GW), neurons in other brain regions, such as the inferior olivary nucleus, cerebellum, basal ganglia, thalamus and cerebral cortex, are also involved. Thus, karyorrhexis is more widely distributed in the more immature brain, implicating neuronal maturation as one of the pathogenetic factors relevant to this type of neuronal cell death.

[A case of chronic persistent cough caused by gastro-esophageal reflux]

Although gastro-esophageal reflux (GER) is one of the major causes of chronic persistent cough (CPC) in the USA and in Europe, it is a rare cause of CPC in Japan. We report a rare case of CPC caused by GER, in which treatment with an H2-blocker or with a proton pump inhibitor was successful. A 65-year-old woman had complained of coughing for over 25 years. Her coughing was not alleviated by treatment with a bronchodilator (beta 2-adrenoceptor agonist), an anti-allergic agent, a corticosteroid, or a sedative. GER was considered as a possible cause of her coughing because exacerbation of the coughing was associated with the development of gastrointestinal symptoms (heartburn). Fiberoptic esophagoscopy showed esophagitis and esophageal herniation of the sliding type. Twenty four-hour monitoring of distal esophageal pH showed that the coughing occurred when the pH dropped below 4, and that the pH was less than 4 for about 7% of the whole monitoring time. An H2-blocker or a proton pump inhibitor completely eliminated the symptoms. Therefore, CPC caused by GER was diagnosed. We found that coughing could be induced by instillation of 0.1 N hydrochloric acid at the distal esophagus, and that the coughing was partially inhibited by inhalation of an anti-muscarinic agent (ipratropium bromide) and by esophageal instillation of 4% xylocaine. These data support the "reflex theory". Although CPC caused by GER is rare in Japan, we should remember that GER can be a cause of CPC even in Japanese patients.