Canine distemper virus does not infect oligodendrocytes in vitro

Dissociated canine brain cell cultures were infected with virulent canine distemper virus (CDV). Double immunofluorescent labelling was done to simultaneously demonstrate viral antigen and specific glial cell markers. Virus containing oligodendrocytes were not found at any stage of the infection. A certain proportion of the infected cells were shown to be astrocytes. It was concluded that CDV has no obvious tropism for oligodendrocytes which could explain the mechanism of demyelination in distemper in vivo.

Identification of mucus glycoprotein fatty acyltransferase activity in human gastric mucosa

The enzymatic activity which catalyzes the transfer of palmitic acid from palmitoyl coenzyme A to gastric mucus glycoprotein was demonstrated in antral and fundic mucosa of normal human stomach. Subcellular fractionation studies revealed that with both types of mucosa the enzyme activity was present in the microsomal fraction. The antral and fundic mucosa also exhibited similar enzyme activities, showed identical pH optimum, and required detergent, NaF and dithiothreitol. Optimum enzymatic activity for fatty acylation of mucus glycoprotein was obtained with 0.5% Triton X-100, 25 mM NaF, and 2 mM dithiothreitol at a pH of 7.4. The 14C-labeled product of the reaction comigrated on CsCl density gradient centrifugation with gastric mucus glycoprotein and contained the ester-bound palmitic acid.

Spread and distribution of viral antigen in nervous canine distemper

Canine distemper virus (CDV) antigen was demonstrated immunocytochemically in the central nervous system (CNS) of 19 dogs killed from 16 to 170 days after infection. In the earliest lesions, infection of glial cells preceded demyelination, and the degree of myelin destruction correlated with the amount of viral antigen in the tissue. It was concluded that initial demyelination in distemper is directly viral-induced, but the nature of the infected glial cells remains uncertain. Ependymal infection and spread of virus in the subependymal white matter was often seen, suggesting invasion of CDV into the CNS along the CSF pathways. Inflammation during the latter stages of the infection appeared to be associated with viral clearance from the CNS in most dogs. In two dogs with chronic progressive neurologic distemper, viral antigen was still present in the brain suggesting that viral persistence and associated immunologic reactions may contribute to further myelin damage. With the exception of one dog that survived for 6 months after infection, viral antigen was no longer detected in the dogs that had recovered.

Distribution of alpha interferon in serum and cerebrospinal fluid after systemic administration

After intravenous infusion of recombinant leukocyte interferon (rIFN-alpha A) to four subjects with an indwelling reservoir, serial serum and cerebrospinal fluid samples were taken over 48 hr and were analyzed for interferon by an enzyme immunoassay method (ELISA). On separate occasions, 18 and 50 X 10(6) of rIFN-alpha A were infused over 10 min. Maximum serum concentrations of rIFN-alpha A ranged from 6720 to 11,000 pg/ml and from 32,900 to 43,400 pg/ml after the 18 and 50 X 10(6) U doses. There was no measurable concentration of rIFN-alpha A in the cerebrospinal fluid of subjects who received 18 X 10(6) U doses. In three of four subjects who received 50 X 10(6) U rIFN-alpha A, concentrations ranged from 17 to 70 pg/ml that were measurable no earlier than 1 hr after the start of the infusion and that in two cases were measurable throughout 24 hr.

Affective disorder not linked to HLA in a large bipolar kindred

Recent studies have suggested genetic linkage between the major histocompatibility complex and affective disorder. We tested this hypothesis in a large pedigree of bipolar affective disorder in which 22 of 37 relatives were interviewed and HLA typing was carried out on 20. The findings provided no evidence for linkage between affective disorder and HLA antigens. Our findings are discussed along with those of other linkage studies bearing on this question.

Special education and medicine: a survey of physicians

A random sample of physicians across the state who were likely to be in contact with parents of handicapped children were surveyed regarding such issues as their knowledge of Public Law 94-142, the impact of this legislation on their practice, their medical school training in the areas of emotional disturbance, learning disabilities, and mental retardation, and their interactions with parents and local school programs. Only 64% of the sample were familiar with this legislation; however, nearly that many were interested in receiving more information regarding this law as well as programs that serve handicapped children. Current response to the needs of parents of handicapped children and implications for future possibilities are discussed.

Enzymatic sulfation of glycolipids by human gastric mucosa

A sulfotransferase activity which catalyzes the transfer of sulfate group from 3'-phosphoadenosine-5'-phosphosulfate to galactosylceramide and triglucosyl monoalkylmonoacylglycerol has been demonstrated in antral and fundic mucosa of normal human stomach. With both types of mucosa maximum activity for sulfation of galactosylceramide was obtained at pH 6.8, whereas the pH optimum for sulfation of triglucosyl monoalkylmonoacylglycerol was 7.8. The reactions were stimulated by the addition of Triton X-100, Mg2+ and F1-. The sulfotransferase activity of fundic mucosa for the synthesis of sulfated glyceroglucolipid was about two times higher than that of antral mucosa, while the enzyme activity for sulfation of glycosphingolipid was similar in both areas of the stomach.

Drosophila nucleosomes contain an unusual histone-like protein

Mononucleosomes prepared from Drosophila melanogaster nuclei contain the four core histones H2A, H2B, H3, and H4 plus an additional histone-like, acid-soluble, chromosomal protein. It is probably the protein designated D2 by Alfageme et al. [Alfageme, C.R., Zweidler, A., Mahowald, A. & Cohen, L.H. (1974) J. Biol. Chem. 249, 3729-3736]. D2 elutes with histone H2A from a Bio-Gel P-100 column, but can be distinguished electrophoretically from H2A and from the other standard Drosophila core histones. The amino acid composition of D2 resembles the compositions of H2A and H2B. However, peptide mapping reveals that D2 is not a simple sequence variant of either H2A or H2B. D2 is present in nuclei from embryos and adult heads, and thus is not restricted to a narrowly defined developmental period. It is present in D. melanogaster and D. virilis, and thus appears to be conserved during the evolution of Drosophila. D2 is present in D. melanogaster chromatin with an approximate frequency of one molecule per five nucleosomes, and must therefore be associated with a subset of nucleosomes. The function of this protein is not known. Its presence in nucleosomes, evolutionary conservation, and comparatively large abundance all suggest that it is an important nucleosomal element. It will be interesting to learn whether this histone-like protein is encoded in a subset of the Drosophila histone gene cluster or is encoded separately.

Conditions Affecting the Molecular Weight of Factor VIII

By purifying Factor VIII while maintaining physiological concentrations of calcium we have recently demonstrated that about 50% of the procoagulant activity is in a very low molecular weight (VLHW) form not associated with the carrier (VIII: RAG). The remainder is carrier associated and elutes at Vo as a high molecular weight (HMW) compound upon Sepharose 6B chromatography. Reduction of the calcium concentration by increasing the amount of citrate added to heparin results in decreasing the ratio of VLMW:HMW from 1:1 in pure heparin to 1:5 in pure citrate. If citrate is replaced with the more strongly chelating EDTA no VLMW is detectable in the plasma. It has also been found that most of the biochemical purification techniques which have been previously used to prepare Factor VIII for study actually result in the aggregation of this VLMW with the carrier to produce the high molecular weight form. This includes: cryoprecipitation, precipitation by polyethylene glycol and storage -80°C. As well, the VLMW material will self-associate upon freezing to produce an aggregate with a molecular weight of 106. However, this material does not cross-react with rabbit antibody directed against VIII: RAG. The data indicate that many of the previously reported biochemical characteristics, including molecular weights, actually describe species which are artifacts of the isolation process rather than those of the physiologically occuring Factor VIII.

Characterization of Low Mololecular Weight Factor VIII

The high molecular weight complex of Factor VIII was isolated from resolubilized cryoprecipitate by polyethylene glycol precipitation followed by chromatography on Bio Gel A15M. Upon rechromatography of this compound in buffer containing 1M NaCl and 1mM benzamidine the low molecular weight sub-unit possessing the procoagulant activity eluted at a volume of 2.3V. SDS polyacrylamide gel electrophoresis of this material in 5% acrylamide gave a single band whose Rf indicated a molecular weight of 150,000. The isoelectric point was determined to be 7.4. A peptide map of pepsin digested, I125 labelled material showed very few peptides which were radioactive and/or fluorescamine positive; as well, there was a relatively large amount of radioactive, non-fluorescamine positive material which was slow moving on pH 2.1 electrophoresis and immobile on chromatography. Amino acid analysis yielded data consistent with the presence of a small amount of protein. Carbohydrate analysis indicated a large amount of neutral hexoses, a very small amount of hexosamines and no detectable sialic acid. These results suggest that the structural features of low molecular weight Factor VIII may account for its anomalous behaviour in standard protein characterization procedures.

Stimulation of mucus and nonparietal cell secretion by the E2 prostaglandins

The effects of prostaglandin E2 (PGE2), 15-methyl prostaglandin E2 (15M), and 16,16-dimethyl prostaglandin E2 (16DM) on gastric mucus and nonparietal cell secretion in rats were measured. Alcian blue binding was used as a measure of gastric mucus. Applied topically, all three agents stimulated nonparietal cell secretion, and PGE2 and 16DM stimulated the secretion of mucus, increasing the fraction in the gastric contents but not that adherent to the mucosa. Topical 15M did not stimulate the production of mucus. Given intranveously, all three agents increased the amount of mucus in the gastric contents without altering the amount of mucus bound to the mucosa. The prostaglandins had no effect on nonparietal cell secretion when given intravenously. These effects could be relevant to the ability of the E2 prostaglandins to protect the gastric mucosa from damage.

Secretion of parathyroid hormone by abnormal human parathyroid glands in vitro

The secretory response of abnormal parathyroid glands obtained surgically from eleven patients with primary and secondary hyperparathyroidsm was tested in vitro. Short term flask studies were used to measure release of parathyroid hormone (PTH) at high (3.0 mM) and low (0.5 mM) calcium. Of eight adenomas, all but one showed increased release of hormone when exposed to low calcium ("responsive to calcium"), the degree of stimulation at three hours ranging from 15 to 209%. By comparison, two normal human glands were stimulated an average of 180%. Glands from three patients with secondary hyperplasia were also responsive to calcium. Thus, parathyroid glands from patients with primary and secondary hyperparathyroidism were characterized by a spectrum of responsiveness to calcium, and absolute "autonomy" was unusual. Even at high calcium concentrations, hormone release persisted at a low but definite level ("basal secretion"). The total number of functioning parathyroid cells is therefore a principal determinant in the oversecretion of PTH in hyperparathyroidism.

Optimized collimators for scintillation cameras

The use of commerically available tantalum or lead tubes permits convenient fabrication of collimators optimized for specific imaging studies.