A case of severe progressive early-onset epileptic encephalopathy: unique GABAergic interneuron distribution and imaging

Early-onset epileptic encephalopathies include various diseases such as early-infantile epileptic encephalopathy with suppression burst. We experimentally investigated the unique clinicopathological features of a 28-month-old girl with early-onset epileptic encephalopathy. Her initial symptom was intractable epilepsy with a suppression-burst pattern of electroencephalography (EEG) from 7 days of age. The suppression-burst pattern was novel, appearing during sleep, but disappearing upon waking and after becoming 2 months old. The EEG showed multifocal spikes and altered with age. Her seizures demonstrated various clinical features and continued until death. She did not show any developmental features, including no social smiling or head control. Head MRI revealed progressive atrophy of the cerebral cortex and white matter after 1 month of age. (123)IMZ-SPECT demonstrated hypo-perfusion of the cerebral cortex, but normo-perfusion of the diencephalon and cerebellum. Such imaging information indicated GABA-A receptor dysfunction of the cerebral cortex. The genetic analyses of major neonatal epilepsies showed no mutation. The neuropathology revealed atrophy and severe edema of the cerebral cortex and white matter. GAD-immunohistochemistry exhibited imbalanced distribution of GABAergic interneurons between the striatum and cerebral cortex. The results were similar to those of focal cortical dysplasia with transmantle sign and X-linked lissencephaly with ARX mutation. We performed various metabolic examinations, detailed pathological investigations and genetic analyses, but could not identify the cause. To our knowledge, her clinical and pathological courses have never been described in the literature.

Low-dose ACTH therapy for West syndrome: initial effects and long-term outcome

BACKGROUND

Most Japanese pediatric neurologists attempt other treatments before using adrenocorticotropic hormone (ACTH) therapy for West syndrome (WS), and even then, they use only a low-dose synthetic ACTH to avoid serious adverse effects. In this multi-institutional study, the authors analyzed the initial effects, adverse effects, and long-term outcome in patients treated with low-dose synthetic ACTH in Japan.

METHODS

The medical records of 138 patients with WS, who were treated with low-dose synthetic ACTH therapy for the first time at the authors' institutions between 1989 and 1998, were analyzed.

RESULTS

At the end of ACTH therapy, excellent effect on seizures was noted in 106 of 138 (76%) patients, good effect in 23 (17%), and poor effect in 9 (7%). Initial effects on EEG were excellent in 53 of 138 (38%) patients, good in 76 (55%), and poor in 9 (7%). As for seizure prognosis at the time of follow-up, 51 of 99 (52%) patients were seizure-free, whereas 48 (48%) patients had seizures. Mental outcome was normal in 6 of 98 (6%) patients, mild mental retardation in 16 (16%), moderate mental retardation in 26 (27%), and severe mental retardation in 50 (51%). The initial effects of ACTH on seizures and long-term outcome were not dose dependent (daily dosage 0.005 to 0.032 mg/kg, 0.2 to 1.28 IU/kg; total dosage 0.1 to 0.87 mg/kg, 4 to 34.8 IU/kg). The severity of adverse effects correlated with total dosage of ACTH, and the severity of brain volume loss due to ACTH correlated well with the daily dosage and total dosage of ACTH.

CONCLUSION

Low-dose synthetic ACTH therapy is as effective for the treatment of WS as the higher doses used in previous studies. The dosage of synthetic ACTH used in the treatment of WS can be decreased as much as possible to avoid serious adverse effects.

[Seizures associated with fever in children of congenital adrenal hyperplasia]

We investigated seizures in 22 children with congenital adrenal hyperplasia (CAH), eight of whom had seizures associated with fever. The follow-up period was 5-18 years. The onset of seizures ranged from 1 to 4 years of age, and the total number of seizures was one to three in all cases. Four cases had seizures twice within 24 hours. None had seizures after 5 years of age. In two of the eight cases, the seizures may have caused by hypoglycemia or hyponatremia, in the remaining six they were considered to be febrile seizures. Three of them had first-degree relatives with febrile seizures. Electroencephalogram was recorded in five cases, with normal results in all of them. One case with febrile status developed localization-related epilepsy later. None showed developmental delay during follow-up. Although seizures in CAH have been ascribed to hypoglycemia and/or metabolic disorders (hyponatremia), our findings implicate unknown factors in the pathogenesis such as excess secretion of corticotropin releasing factor (CRF) under stress, prolonged elevation of CRF during fetus life and linkage between CAH and febrile seizures on the chromosome 6.

Retroviral vector-mediated gene expression in human CD34+CD38- cells expanded in vitro: cis elements of FMEV are superior to those of Mo-MuLV

A novel murine stromal cell line, HESS-M28, was established, which supports the expansion of human CD34+CD38- cells more than 300-fold in vitro in the presence of human IL-3 and SCF. These cells were used in an attempt to evaluate cis-acting elements of retroviral vectors in human primitive hematopoietic cells. Cord blood cells were cultured on top of the mixed cell layers of the stromal cell line, HESS-M28, and retroviral vector-producing cells. The FMEV-type vector SF/Lyt contained the spleen focus-forming virus U3 and the MESV primer-binding site (PBS), while MO3/Lyt contained the U3 region and PBS from Mo-MuLV. After transduction by the FMEV-type and Mo-MuLV-based vectors, expression of the marker gene murine CD8 (mCD8) was examined in CD34-, CD34+, and CD34+CD38- cells. In CD34+ and CD34+CD38- cells, expression of mCD8 was higher with the FMEV-type vector, SF/Lyt, compared with the cells transduced by the Mo-MuLV-based vector MO3/Lyt, although the expression was comparable in CD34- cells. Expression of marker genes was also confirmed in long-term culture-initiating cells (LTC-ICs) and SCID-repopulating cells (SRCs).

Cloning of human cDNAs for Apg-1 and Apg-2, members of the Hsp110 family, and chromosomal assignment of their genes

In mice, the Hsp110/SSE family is composed of the heat shock protein (Hsp)110/105, Apg-1 and Apg-2. In humans, however, only the Hsp110/105 homolog has been identified as a member, and two cDNAs, Hsp70RY and HS24/p52, potentially encoding proteins structurally similar to, but smaller than, mouse Apg-2 have been reported. To clarify the membership of Hsp110 family in humans, we isolated Apg-1 and Apg-2 cDNAs from a human testis cDNA library. The human Apg-1 was 100% and 91.8% identical in length and amino acid (aa) sequence, respectively, to mouse Apg-1. Human Apg-2 was one aa shorter than and 95.5% identical in sequence to mouse Apg-2. In ECV304, human endothelial cells Apg-1 but not Apg-2 transcripts were induced in 2 h by a temperature shift from 32 degrees C to 39 degrees C. As found in mice, the response was stronger than that to a 37-42 degrees C shift. The human Apg-1 and Apg-2 genes were mapped to the chromosomal loci 4q28 and 5q23.3-q31.1, respectively, by fluorescence in-situ hybridization. We isolated cDNA and genomic clones encompassing the region critical for the difference between Apg-2 and HS24/p52. Although the primer sets used were derived from the sequences common to both cDNAs, all cDNA and genomic clones corresponded to Apg-2. Using a similar approach, the relationship between Apg-2 and Hsp70RY was assessed, and no clone corresponding to Hsp70RY was obtained. These results demonstrated that the Hsp110 family consists of at least three members, Apg-1, Apg-2 and Hsp110 in humans as well as in mice. The significance of HS24/p52 and Hsp70RY cDNAs previously reported remains to be determined.

Efficient gene transfer by hybrid retroviral vectors to murine spermatogenic cells

Using murine spermatogenic cell lines GC-1 spg and GC-2 spd(ts) as target cells, an attempt was made to design a retroviral vector that would transduce genes efficiently. Promoter activities of various retroviral long terminal repeats (LTRs) were examined by using chloramphenicol acetyltransferase (CAT) as a reporter. The U3 region of spleen focus-forming virus (SFFVp) showed higher enhancer activity than that of Moloney murine leukemia virus (Mo-MuLV) in both cell lines. The U3 region of myeloproliferative sarcoma virus (MPSV) showed higher activity only in GC-1 spg cells. Expression was suppressed by the repressor element of the primer-binding site (PBS) of the Moloney-related virus. The efficiency of transduction of the multidrug-resistance gene (mdr-1) by an Mo-MuLV-based vector was compared with hybrid vectors consisting of the murine embryonic stem cell virus (MESV) PBS and the LTR of either SFFVp or MPSV. Rhodamine efflux assays and colchicine-resistant colony-forming assays demonstrated higher gene expression by the hybrid vectors. Amphotropic and ecotropic receptors were found to be expressed and functional in both cell lines. Thus, these hybrid vectors represent a powerful tool by which to transfer genes into spermatogenic cells.

[A clinical study of cerebral palsy in Shiga; 1977-1986--I. Etiological analysis of various types of cerebral palsy]

Two hundred and two cases of CP in Shiga Prefecture, born between April 1977 and March 1987, were classified at 6 years of age into 5 groups: 69 with spastic diplegia (34%), 62 with tetraplegia (31%), 33 with hemiplegia (16%), 23 with the dyskinetic type (11%) and 15 with the ataxic type (7%). The rate of preterm birth was 32%, being highest in the spastic diplegia group. The etiological and risk factors were analysed in these cases. In term infants with spastic diplegia, the presumptive causes were unknown in 55%, prenatal in 28%, and perinatal in only 17%. In preterm infants with spastic diplegia, periventricular leukomalacia was the most important. In term infants with tetraplegia, brain anomalies and hypoxic-ischemic encephalopathy were the two main causes. In preterm infants with tetraplegia, the presumptive causes were perinatal in 67%. In most of the patients with hemiplegia, there were unilateral lesions such as middle cerebral artery infarction and cerebral hemiatrophy. Most of the dyskinetic cases had perinatal causes such as bilirubin encephalopathy in 9 patients. In 40% of the ataxic cases, there were brain anomalies.

[A clinical study of cerebral palsy in Shiga; 1977-1986--III. Diagnosis and treatment of various types of cerebral palsy]

The age at the first clinical referral or diagnosis of cerebral palsy (CP), the age at the onset of treatment, the route of referral, and the kind of school entered were investigated in 202 cases of CP in Shiga Prefecture (69 with spastic diplegia, 62 with tetraplegia, 33 with hemiplegia, 23 with the dyskinetic type and 15 with the ataxic type) born between April 1977 and March 1987. In the hemiplegia, spastic diplegia and ataxic types, the age at the first clinical referral or diagnosis, was above 1 year in 42%, 39% and 33%, respectively. In the tetraplegia and the dyskinetic types, by contrast, such a delay occurred in only 9% and 4%, respectively. Cases of the former three types were referred from medical institutions less frequently (53% in the ataxic type, 52% in spastic diplegia and 40% in hemiplegia) than those of the latter two types (76% in tetraplegia and 61% in the dyskinetic type). About 30% of the cases were referred from health centers (38% in spastic diplegia, 33% in hemiplegia, 30% in the dyskinetic type, 20% in the ataxic type and 16% in tetraplegia). A considerable number of cases visited a clinic without reference (27% in hemiplegia, 27% in the ataxic type, 10% in spastic diplegia, 9% in the dyskinetic type, and 8% in tetraplegia). Fifty-three percent of the cases entered an elementary school (ordinary classes in 30% and special classes in 23%), 41% a special school, and 5% entered a protective institution. The early diagnosis of hemiplegia, spastic diplegia and the ataxic type of CP was difficult in some cases. Cases with suspected signs of CP should be referred to clinic early in the absence of definite diagnosis.

[A clinical study of cerebral palsy in Shiga; 1977-1986--II. Severity of the disability and complications in various types of cerebral palsy]

The severity of the disability and complications was evaluated at 6 years of age in 202 cases of cerebral palsy (CP) in Shiga Prefecture (69 with spastic diplegia, 62 with tetraplegia, 33 with hemiplegia, 23 with the dyskinetic type and 15 with the ataxic type) born between April 1977 and March 1987. The degree of gross motor disability differed among the clinical types, being mild in 45%, moderate in 17%, and severe in 39%. Gross motor disability was generally correlated with mental retardation, with some exceptions. Some non-ambulatory cases exhibited a normal or subnormal mentality, and most of such cases had been preterm infants with spastic diplegia. Most cases with mild gross motor disability and severe or moderate mental retardation had been term infants. Forty-eight percent suffered from epilepsy (25% in spastic diplegia, 86% in tetraplegia, 45% in hemiplegia, 39% in the dyskinetic type and 13% in the ataxic type). Microcephaly was noted in 35% (66% in tetraplegia and about 20% in other types).

[Efficacy of zonisamide in West syndrome]

The efficacy of zonisamide (ZNS) was studied in 16 patients (11 males, 5 females) with West syndrome (WS), symptomatic in 13 and cryptogenic in 3. They did not respond to pyridoxal phosphate (12 cases) or valproate (16 cases). The mean age of onset of WS was 4.4 (2-9) months. ZNS was administered from 3 to 9 months of age (mean 6.1). Four cases (2 cryptogenic and 2 symptomatic) became seizure free. Two had more than 50% seizure reduction. Ten infants remained unchanged or showed less than 50% seizure reduction. In the 4 responders, the effective dose was 4-8 mg/kg (mean 5.8), and the serum ZNS concentration was 10-21 micrograms/ml (mean 13.8). One had relapse of WS after 4 months. Three with normalized EEG remained seizure-free during the follow-up period (12-26 months). One case developed a transient drowsiness, but no serious side effects were observed. These data suggest ZNS may be regarded as a therapy of choice before synthesized ACTH therapy in the management of WS.

Neopterin Concentrations of Serum and Cerebrospinal Fluid in Febrile Convulsion, Aseptic Meningitis and Influenza Encephalopathy

The concentration of total neopterin in serum and cerebrospinal fluid (CSF) was measured in cases of febrile convulsion, aseptic meningitis and influenza encephalopathy. In febrile convulsion except for exanthem subitum, the concentrations of CSF neopterin (26± 11, Mean±SD, n=6) were all within normal range while those of serum neopterin (66± 20, n=8) were significantly higher (p < 0.05). In aseptic meningitis, on the other hand, the concentrations of CSF neopterin (194± 130, n=13) were significantly higher than those of serum (33±23, n=11, p < 0.05). In influenza encephalopathy, both concentrations of serum neopterin (329±478, n=13) and CSF neopterin(179±131, n=11) were much higher than the control range. Our results indicate that the primary immunoreacting site is the central nervous system (CNS) for aseptic meningitis, the periphery for febrile convulsion except for exanthem subitum and both the periphery and the CNS for influenza encephalopathy. Measurements of neopterin concentrations in CSF as well as in serum may thus constitute an immediate aid for early differentiation of CNS infection from peripheral infection as well as for early detection of viral encephalopathy caused by viruses such as the influenza virus or the human herpes virus 6.

[Home mechanical ventilation with nasal intermittent positive pressure ventilation for a boy with congenital central hypoventilation syndrome]

We report a 4-year-old boy with congenital central hypoventilation syndrome (CCHS) successfully treated with home mechanical ventilation with nasal intermittent positive pressure ventilation (NIPPV) during sleep hours. He had had frequent severe apneic attacks from the neonatal period. At 8 months, he was treated with positive pressure ventilation following a tracheostomy. At 4 year and 2 months, NIPPV was attempted because of recurrent respiratory tract infections and cor pulmonale. The tracheostomy was successfully abandoned 6 months later. Adequate ventilation has been maintained for more than 3 years without troubles. NIPPV is an effective and non-invasive treatment of CCHS that it significantly improves the quality of life during daytime.

[Incidence patterns of cerebral palsy in Shiga, Japan, 1977-1986--an epidemiological study]

An epidemiological study of cerebral palsy (CP) in Shiga Prefecture, was performed by reviewing medical records of the Medical Center for Children in Shiga (MCCS) and related hospitals. The total number of CP patients identified at 6 years old was 202 (117 boys and 85 girls) who were born during the ten years period between 1977-1986. The average prevalence of CP in Shiga Prefecture was calculated as 1.09 per 1,000 school children aged 6 years. The prevalence of CP was 9 fold among low birth weight infants (1,500-2,499 g) and 41 fold among very low birth weight infants (< 1,500 g), compared with that of mature infants (> or = 2,500 g). One hundred and thirty nine cases (69%) were term infants, and 63 cases (31%) were preterm. Etiology of 139 term cases was considered to be prenatal in 50 cases (35%), perinatal in 37 cases (26%), postnatal in 3 cases (2%) and untraceable in 49 cases (35%), whereas prenatal in 12 cases (19%), perinatal in 7 cases (11%), and untraceable in 44 cases (70%) of 63 preterm cases. The prevalence rate of CP was fairly constant throughout the whole period of 1977-1986, but the term cases with perinatal etiologies significantly decreased in the period of 1982-1986, compared with those in the preceding period of 1977-1981. Children born weighting less than 1,500 g significantly increased in the later period. The improvement of perinatal care seems to play a major role on these changes. Sixty percent of term cases and 20% of preterm cases were considered to be due to prenatal factors which could not be prevented by the improvement of perinatal care.

Somatic cell mutation frequency at the HPRT, T-cell antigen receptor and glycophorin A loci in Cockayne syndrome

Skin fibroblasts of patients with Cockayne syndrome (CS) are hypersensitive to the lethal or mutagenic effect of ultraviolet light, which may cause genetic instability. Up to now, however, no systematic study of in vivo somatic cell mutation in CS cells has been reported. This article describes our investigation of the mutation frequencies (Mfs) at three different loci, i.e. hypoxanthine-guanine phosphoribosyl transferase (HPRT), T-cell antigen receptor (TCR) and glycophorin A (GPA), in six patients with CS. Mfs at the HPRT and TCR loci were found to be within the normal range as determined in age-matched controls. In the GPA locus of two patients, there was a slight increase, but it was much smaller than that reported in other DNA repair deficient syndromes. The frequency of spontaneous HPRT mutation in Epstein-Barr virus transformed B-lymphoblastoid cells derived from CS patients was similar to that in cells from normal children. The molecular characterization of the representative HPRT mutant T cell clones from CS patients did not show any structural alterations. These results may explain, at least in part, why CS is not associated with predisposition to cancer.

A database of genetically determined neurological conditions for clinicians

Progress is reported in the establishment of a database of genetically determined neurological conditions. There are now 1,300 conditions and 3,400 references store on the hard disk of a microcomputer. The database is searched, and a differential diagnosis obtained, by choosing a small number of signs and symptoms from a comprehensive list of cardinal features.

Dominantly inherited congenital cerebellar ataxia with atrophy of the vermis

We report a mother and daughter with congenital cerebellar ataxia and normal intelligence. Computed tomography revealed localized atrophy of the cerebellar vermis. This is the second case report of dominantly inherited, nonprogressive, congenital cerebellar ataxia.

The use of a computerised database for the diagnosis of a rare neurological syndrome

A database which runs on an office microcomputer is being developed for the diagnosis of genetically determined neurological disorders. At present about 1100 conditions with their clinical features and 3000 references are stored in the database. We discuss a family with 3 sibs affected by a unique neurological disorder and show how the database is used. The 3 sibs, 4, 5 and 10 years old, show the same clinical course characterized by congenital cataracts, microcephaly, hypotonia, mental retardation, pyramidal signs and choreoathetoid movements starting in early childhood. The parents are first cousins of Bangladeshi origin. This condition does not appear in published report and is not listed in the database. It can therefore be concluded that the sibs have a unique autosomal recessive disorder.

Nuclear and nucleolar damage in adriamycin-induced toxicity to rat sensory ganglion cells

A single dose (10 mg/kg) of Adriamycin was given to 23 adult Wistar rats and the spinal ganglia were studied from 6 h to 15 days after. As previously described, this drug results in the appearance of 'clear' areas in the nuclei of rat spinal ganglion cells as seen by light and by electron microscopy. The 'clear' areas become less conspicuous during the week before the onset of cytoplasmic degeneration. In addition, nucleolar changes become increasingly evident with time after injection. Fibrillar centres enlarge and nucleolar segregation is present from 24 h onwards, although the latter is invariably partial and more readily seen with the electron microscope. Nucleolar fragmentation is seen more frequently from 3 days onwards and nucleolar enlargement is common from 6 days. Early cytoplasmic abnormalities are associated with pronounced loss of Nissl substance. Adriamycin must bind extensively to nuclear DNA in spinal ganglion cells, causing the 'cleared' nuclear areas and the changes in dense chromatin. In addition, the binding of Adriamycin to nucleolar DNA with disturbance to nucleolar functions must be important in producing later cytoplasmic changes that precede cell death. There are thus similarities between the action of Adriamycin on these cells and those of Cisplatin, although in the latter intoxication the nuclear effects are significantly less prominent.

Improvement in auditory brainstem response of hyperbilirubinemic infants after exchange transfusions

Auditory brainstem response tests were performed before and after exchange transfusions in 6 infants with hyperbilirubinemia. The latencies of Waves I, II, and V decreased significantly after the exchange transfusions (p less than .05, p less than .02, p less than .005, respectively) and I-V interpeak latencies also were decreased (p less than .01). However, the latencies of Wave I both before and after exchange transfusions were within normal limits. The central conduction times were prolonged by hyperbilirubinemia, but the peripheral auditory pathways were not impaired. These auditory brainstem response abnormalities became normal with decreased serum bilirubin concentration. Neonatal hyperbilirubinemia is associated with transient brainstem lesions which are reversible in the early stages. Auditory brainstem response testing is an effective and readily available technique for detecting bilirubin neurotoxicity.

The effects of cisplatin on rat spinal ganglia: a study by light and electron microscopy and by morphometry

Cisplatin given in doses of 0.5-2 mg to Wistar and to Sprague-Dawley rats produced nucleolar segregation of the dense fibrillar from the granular component in spinal root ganglion cells. The nucleolar segregation, found to the same extent in large and small neurons, was confirmed by specific silver staining and by electron microscopy. After repeated doses of 1 mg or 0.5 mg, up to 40% of affected nucleoli were observed by light microscopy. Focal clearing of the nucleoplasm of nuclei also occurred. Disorganisation of ribosomes was found in more severely intoxicated animals, especially in large light cells with shrinkage of the Nissl substance and apparent increase in neurofilaments, the latter occasionally distending the initial segment of the axon, but never extending further. Hypertrophy of the satellite cells with increase in the perineuronal intercellular spaces, often associated with irregular, scalloped nuclear and cell outlines, suggested that neuron shrinkage had occurred. This was confirmed by morphometry and marked alterations were found in nucleolar-to-nuclear and nucleolar-to-cell diameter ratios, nuclear and cell diameters were also somewhat reduced without change in the nucleus-to-cell ratios. Peripheral sensory nerve degeneration was not seen, and the animals died from non-neural causes. The probable role of these events in the production of sensory neuropathy is discussed.

Tentorial cavernous angioma with calcification in a neonate

A cavernous angioma of the tentorium cerebelli, first disclosed by perinatal serial ultrasonographic studies, was extirpated totally without remarkable neurological deficit in a neonate. The tumor was accompanied by a calcified expansive hematoma in the posterior fossa. To our knowledge, this is the first case not only of cavernous angioma treated surgically and verified histologically in a neonate, but also of a calcified hematoma revealed on a conventional skull x-ray film at birth. This case suggests the possibility of hemorrhage from intracranial cavernous angioma early in life, even prenatally, and emphasizes the necessity for early diagnosis and early treatment of intracranial cavernous angiomas.

Neurotoxicity of vincristine after the osmotic opening of the blood-brain barrier

The direct effect of intravascularly injected vincristine on the rat brain was investigated after the osmotic opening of the blood-brain barrier. This was opened unilaterally by injecting 2.5 ml of 1.4 molal mannitol solution into the right carotid artery through a cannula inserted in the external carotid artery in retrograde fashion. Vincristine (0.75 mg/kg) was then injected into either the carotid artery or into a vein. Animals, thus treated, developed left hemiparesis and choreo-athetoid head motion within several days. Microscopical analysis revealed 1 intracytoplasmic eosinophilic inclusions at an early period, 2 neuronal argyrophilic change and axonal thickening with spheroid formation at later times, and 3 glial mitotic arrest, a finding not reported in the previous studies with intrathecal injection of vincristine. Neuronal changes were usually confined to the selected area in the midbrain, whereas glial mitotic figures were seen in the hippocampus, midbrain and cerebellum. These changes are thought to be direct effects of the vincristine binding with cellular microtubules, including mitotic spindle tubules and neurotubules. The transient opening of the blood-brain barrier seems to be a useful technique for studying the experimental neurotoxicology of drugs to which the blood-brain barrier is impermeable.

Syndrome of inappropriate secretion of antidiuretic hormone caused by vincristine therapy: a case report of the neuropathology

The syndrome of inappropriate secretion of antidiuretic hormone is a rare but well-recognized neurotoxic side effect of vincristine therapy. The first neuropathological report of a case is presented. A 6-month-old boy with skin leukemia developed inappropriate secretion of antidiuretic hormone caused by vincristine. Postmortem examination revealed axonal spheroids in the ansa lenticularis and the area surrounded by the substantia innominata, amygdala and supraoptic nucleus. The lesion was confined to that area and the neurosecretory neurons were intact with well preserved neurophysin. The pathological findings suggest that these fibers play a role in the development of inappropriate secretion of antidiuretic hormone caused by vincristine therapy.

Reversible osmotic opening of the blood-brain barrier. Prevention of tissue damage with filtration of the perfusate

Histological and fluoromicroscopical studies were performed in order to obtain information about reversibility and associated tissue damage of an osmotic opening of the blood-brain barrier. Three ml of 1.4 M mannitol solution were perfused through the right carotid artery of a rat, and the opening of the blood-brain barrier was examined by using EVans blue as a tracer. The barrier was opened for 60-120 minutes and then reestablished without gross neurological defect. Microscopically, however, edematous change and microinfarcts were often observed, which might be due to microembolism of recrystallized mannitol. With filtration of the perfusate through a millipore filter, the blood-brain barrier was reversibly opened without any tissue damages. This could be a useful therapeutic technique and an experimental model for neurotoxicology.