Cluster of perinatal events identifying infants at high risk for death or disability.

To determine the prognostic import of neonatal seizures according to the presence or absence of certain other postnatal characteristics, we studied a population of 39,000 infants with birth weight greater than 2500 gm. Children with clinically recognized neonatal seizures and 5-minute Apgar scores less than or equal to 5 and who had at least one of five signs compatible with neonatal encephalopathy had a risk for first-year death of 33%. Survivors of this cluster of events (low Apgar score-abnormal signs-seizures) had a risk for motor disability of 55%.

Distributions of pro-vasopressin expressing and pro-vasopressin deficient CRH neurons in the paraventricular hypothalamic nucleus of colchicine-treated normal and adrenalectomized rats.

The corticotropin-releasing hormone (CRH) neurosecretory system in normal rats consists of two major subpopulations of parvicellular neurons in the hypothalamic paraventricular nucleus distinguished by the presence or absence of coexistent vasopressin precursor (pro-AVP)-derived peptides. These neurons project to the external zone of the median eminence, where the two subtypes of axons (CRH +/AVP + and CRH+/AVP-) were previously found to be approximately equal in number. The present study was undertaken 1) to determine whether the relative numbers of pro-AVP expressing and pro-AVP deficient perikarya in the paraventricular nucleus corresponded to what we previously found for the axons in the median eminence, 2) to map the two cell types throughout the entire paraventricular nucleus to determine whether significant differences existed in their distributions, and 3) to ascertain whether or not the pro-AVP deficient subpopulation expressed pro-AVP after adrenalectomy.

Motor fluctuations in Parkinson's disease: central pathophysiological mechanisms, Part II.

The contribution of central pharmacodynamic mechanisms to the pathogenesis of motor fluctuations in advanced Parkinson's disease was studied in 29 patients by evaluating their acute response to intravenously injected levodopa. While the threshold dose for an antiparkinsonian effect did not change, that for induction of dyskinesia showed a progressive reduction in 4 groups: (1) levodopa-naive patients, (2) those with a stable response to oral administration, and (3) those with wearing-off or (4) on-off fluctuations. Concomitantly, the therapeutic window for levodopa narrowed and the levodopa dose-antiparkinsonian response slope increased.

Motor fluctuations in Parkinson's disease: central pathophysiological mechanisms, Part I.

The duration of the antiparkinsonian action of levodopa was studied in 48 patients with various response patterns to the oral administration of the dopamine precursor. Deterioration in motor scores after abrupt cessation of a steady-state intravenous levodopa infusion occurred at two successive rates: an initial rapid phase followed by a terminal slower phase. Efficacy half-time decreased and initial efficacy decay slope increased with progression of levodopa response groups from never treated to stable responders, and then to fluctuating responders of the wearing-off type and finally of the on-off type.

Organization and expression of the human myelin basic protein gene.

The human brain contains four isoforms of myelin basic protein (MBP), previously identified by cDNA cloning. We have now isolated and characterized genomic clones encoding the human MBP gene. The gene is 45 kb in extent and consists of seven exons.

Adoptively transferred experimental autoimmune encephalomyelitis in SJL/J, PL/J, and (SJL/J x PL/J)F1 mice. Influence of I-A haplotype on encephalitogenic epitope of myelin basic protein.

Guinea pig basic protein (GPBP)-immune lymph node cells (LNC) from SJL, PL, and SJL x PL (F1) mice proliferated to whole GPBP and GPBP fragments 1-37, 43-88, and 89-169. All three strains of mice developed experimental allergic encephalomyelitis (EAE) by active immunization with whole GPBP or by passive transfer of LNC cultured with whole GPBP. SJL (H-2s) and PL (H-2u) mice developed EAE by active immunization with fragments 89-169 or 1-37, respectively, or by passive transfer of LNC cultured with the same Ag.

Muscarinic receptor-mediated increase in cAMP levels in SK-N-SH human neuroblastoma cells.

Stimulation of muscarinic cholinergic receptors in SK-N-SH human neuroblastoma cells resulted in a 1.5-4 fold increase in intracellular cAMP levels. This unusual response was sensitive to atropine and pirenzepine but insensitive to pertussis toxin.

Analysis of the molecular basis of HLA-A3 recognition by cytotoxic T cells using defined mutants of the HLA-A3 molecule.

The structure-function relationships in human class I HLA molecules have been examined by the analysis of two T cell-defined subtypes of HLA-A3 (A3.1 and A3.2).

Activation of ion channels in tumor cells by leukoregulin, a cytostatic lymphokine.

We used the whole-cell patch-clamp recording technique to study the effects of leukoregulin (LR), a cytostatic lymphokine produced by activated human peripheral blood lymphocytes, on the electrical properties of K562 tumor cells. LR induced changes in the membrane excitability in 33 of 55 cells studied. A minute or more after application, LR elicited a complex and reversible electrical response.

Acute reduction of dopamine levels alters responses of basal ganglia neurons to selective D-1 and D-2 dopamine receptor stimulation.

Extracellular single unit recording techniques were used to investigate dopamine agonist-induced changes in the tonic activity of globus pallidus neurons in normal control rats, and in rats in which dopamine levels were acutely reduced by alpha-methyl-para-tyrosine (AMPT) pretreatment. Systemic administration of the nonselective D-1/D-2 agonist apomorphine consistently induced large increases in the firing rates of globus pallidus neurons, as shown previously. The D-1 agonist SKF 38393 frequently induced no change in pallidal cell firing rates with doses up to 20 mg/kg; however, firing rates of 40% of the cells were stimulated by more than 20% of baseline and 14% were partially inhibited after 20 mg/kg SKF 38393.

Expression of the human beta-globin gene following retroviral-mediated transfer into multipotential hematopoietic progenitors of mice.

Efficient transfer of the beta-globin gene into primitive hematopoietic progenitors was achieved with consistent and significant expression in the progeny of those cells. Retroviral vectors containing the intact genomic human beta-globin gene and the neomycin (G418)-resistance (neoR) gene were constructed. These gave titers of 10(6) or more neoR colony-forming units/ml when packaged in psi 2 cells.

Effects of botulinum toxin injections on speech in adductor spasmodic dysphonia.

Adductor spasmodic dysphonia involves an overadduction of the vocal folds during speech causing uncontrolled voice and pitch breaks and slow, effortful speech. The disorder is resistant to speech therapy and often recurs following initial benefit from unilateral recurrent laryngeal nerve resection. Botulinum toxin injections into multiple sites of the thyroarytenoid muscle on one side were performed in 16 patients.

Stereotaxic implantation of dispersed cell suspensions into brain. A systematic appraisal of cell placement and survival.

The application of several recent advances in cell biology, brain implantation, and cell-mediated tumor immunotherapy requires successful and reproducible placement of viable cell suspensions into brain. Stereotaxic implantation is being used to inject cytotoxic lymphocytes into gliomas and to replace dopaminergic cells in parkinsonian models. Systematic assessment of the factors that influence success in implantation of cell suspensions into solid tissues is needed.

Transient outward current (IA) in clonal anterior pituitary cells: blockade by aminopyridine analogs.

Whole cell voltage-clamp recordings from GH3 cells, a clonal cell line derived from a rat anterior pituitary tumor, demonstrated a rapidly activating and inactivating ("transient") voltage-dependent outward current. This current, referred to as IA, was elicited by step depolarization from holding potentials negative to -50 mV, showed strong outward rectification at potentials positive to -30 mV, and exhibited steady state inactivation with V 1/2 near -64 mV. The current rose to a peak within less than 10-20 ms following depolarization and decayed in two exponential phases, IAf and IAs, with time constants of 30-50 and 500-700 ms, respectively.

Remyelination of central nervous system lesions in experimental genital herpes simplex virus infection.

To study spinal cord remyelination in a model of genital herpes simplex virus type 2 (HSV-2) infection, adult female mice were inoculated by a vaginal route. At intervals up to 6 months after infection, cord tissues were removed and examined by light and electron microscopy and by immunohistochemical methods. As a consequence of acute infection, 60% of mice developed multifocal central nervous system (CNS) demyelinative lesions in the lower thoracic, lumbar, or upper sacral cord.

Further characterization of malignant glioma-derived vascular permeability factor.

The nature of vascular permeability factor (VPF) activity derived from serum-free conditioned medium containing cultured human malignant glial tumors has been further investigated. A 1000-fold purification was accomplished by sequential heparin-Sepharose affinity chromatography and high-performance liquid chromatography gel filtration chromatography steps. Vascular permeability factor activity falls into a molecular weight range of 41,000 to 56,000 D.

Toxoplasmosis: maternal and pediatric findings in 23,000 pregnancies.

An analysis of the antibody titers to toxoplasmosis for 22,845 pregnant women in the Collaborative Perinatal Project was conducted in relation to clinical and laboratory findings in the mothers and children through 7 years of age. More than 900 observations were considered for each mother and child. The major findings were in the children and included a predicted doubling in the frequency of deafness among children born to women with antibody to toxoplasmosis, a predicted 60% increase in microcephaly, and a 30% increase in low IQ (less than 70) in association with the presence of high maternal antibody titer (256 to 512) to toxoplasma.

Multiple sulfatase deficiency with a novel biochemical presentation.

Deficient activities of cerebroside-sulfatase, N-Acetylgalactosamine-4-sulfatase and iduronide 2-sulfatase in the lymphocytes of a patient suspected of metachromatic leukodystrophy, established the diagnosis of multiple sulfatase deficiency (MSD). Cultured skin fibroblasts (of early passage) from the patient had normal levels of activity for the three sulfatases. One week after the first examination, the activities of the three sulfatases in the fibroblasts of the patient declined and within a month were 4%-29% of normal.

Site-directed mutagenesis of human beta-adrenergic receptors: substitution of aspartic acid-130 by asparagine produces a receptor with high-affinity agonist binding that is uncoupled from adenylate cyclase.

By using oligonucleotide-directed mutagenesis, we have produced a point mutation (guanine to adenine) at nucleotide 388 of the gene for human beta-adrenergic receptor (beta AR) that results in a substitution of asparagine for the highly conserved aspartic acid at position 130 in the putative third transmembrane domain of the human beta AR ([Asn130]beta AR). We have examined the functional significance of this mutation in B-82 cells continuously expressing the mutant [Asn130]beta AR. The mutant [Asn130]beta AR displayed normal antagonist binding but unusually high-affinity agonist binding (5- to 10-fold higher than wild-type beta AR), consistent with a single class of high-affinity binding sites.

Mitogenesis of 3T3 fibroblasts induced by endogenous ganglioside is not mediated by cAMP, protein kinase C, or phosphoinositides turnover.

The B subunit of cholera toxin, which binds specifically to ganglioside GM1, stimulates DNA synthesis in quiescent Swiss 3T3 fibroblasts grown in chemically defined medium. The mitogenic response to the B subunit was potentiated by insulin and other growth factors. To elucidate the mechanism by which the B subunit stimulates cell growth , its effects on several transmembrane signaling systems which have been suggested to play a vital role in cell growth regulation were examined.

Phencyclidine selectively blocks the sustained voltage-dependent potassium conductance in PC12 cells.

We investigated the effects of phencyclidine (PCP), a psychotomimetic dissociative anesthetic, and several related drugs on voltage-dependent K+ currents in PC12 cells, a neuron-like clonal cell line derived from a rat pheochromocytoma. Whole-cell voltage clamp recordings demonstrated two kinetically distinct voltage-dependent outward (K+) current components in these cells: a rapidly activating and inactivating component, IA, that was selectively eliminated by 4-aminopyridine (2 mM) and a slowly activating, minimally inactivating (sustained) component, IK, that was specifically blocked by tetraethylammonium (20 mM). PCP (1-100 microM) produced a dose-dependent blockade of both IK and IA, however, at low doses the drug selectively reduced IK with little effect on IA; the IC50s for blockade of IK and IA were 4 and 25 microM, respectively.

Identities, antigenic determinants, and topographic distributions of neurofilament proteins in the nervous systems of adult frogs and tadpoles of Xenopus laevis.

Three proteins with nominal molecular weights of 73 kDa (XNF-L), 175 kDa (XNF-M), and 205 kDa (XNF-H) were identified as putative neurofilament proteins in the nervous system of the frog, Xenopus laevis. These conclusions were based on four criteria: (1) these proteins were enriched in cytoskeletal preparations; (2) they reacted with a monoclonal antibody (anti-IFA) that cross-reacts with an epitope found in all intermediate filament proteins; (3) they cross-reacted with monoclonal antibodies directed against specific mammalian neurofilaments; and (4) antibodies that reacted with these proteins on Western blots specifically stained neurons in immunohistochemical analyses. The neurofilament proteins in Xenopus were antigenically similar, but not identical to mammalian neurofilament proteins.

Early appearance of type II astrocytes in developing human fetal brain.

To compare rat and human glial development, we examined the cellular composition of human fetal brain in short-term cultures and fresh cell suspensions from fetal ages ranging from 7 to 16 weeks, utilizing the cell type-specific markers which define glial subsets in rats. Here we report that unlike the early rat central nervous system (CNS), 7-10 week human fetal brain contains mostly astrocytes that can be characterized as type II rather than type I. Type I astrocytes become more prevalent in 16-week gestational age human brain.

Electrotonic architecture of type-identified alpha-motoneurons in the cat spinal cord.

1. Measurements of input resistance (RN), time constant (tau 0), and electrotonic length (Lpeel) were derived from intracellular voltage changes produced by injection of current pulses in six type-identified triceps surae alpha-motoneurons. The motoneurons were labeled with horseradish peroxidase and subsequently reconstructed and measured from serial sections.