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J Rego

Publications and source records attributed to J Rego.

8 recordsLinked to original sources

Myelin basic protein in experimental allergic encephalomyelitis is not affected at the posttranslational level: implications for demyelinating disease.

The microheterogeneity of myelin basic protein, expressed as the ratio between the least cationic (C-8) charge isomer and the most cationic (C-1), was examined in experimental allergic encephalomyelitis (EAE) cases. These included acute EAE of 2 months' duration induced with bovine proteolipid protein in complete Freund's adjuvant (CFA), chronic EAE induced with mouse spinal cord homogenate in varying doses from 0.5 to 2.0 mg in CFA, and chronic relapsing EAE of 12 months' duration induced with synthetic peptide 139-151 of the proteolipid protein sequence. The C-8/C-1 ratio was within the normal range for all groups of animals. However, the C-8/C-1 ratio was six- to sevenfold increased in a spontaneously demyelinating transgenic model, ND4, which contains 70 copies of the cDNA for DM20 (Mastronardi et al.: 1996). Since an increase in the C-8/C-1 ratio was also observed in victims of multiple sclerosis but not other neurological diseases, the ND4 model may address primary changes prior to demyelination, while the EAE model addresses the autoimmune aspects of the disease.

Animals↗

Refractory depression treated with high doses of monoamine oxidase inhibitor.

Two treatment-refractory cases of depression were treated with doses of monoamine oxidase inhibitors (MAOIs) that exceeded the recommended therapeutic range. Both patients improved without any side effects. It appears that high doses of MAOIs when used with caution in responsible patients may be another method for treating refractory depression.

Adult↗

Computed tomography of choledocholithiasis.

Computed tomography (CT) correctly diagnosed common bile duct stones in 19 (90%) of 21 surgically proven cases. CT demonstrated calculi in all 13 patients with calcium bilirubinate common duct stones and six of eight patients with predominantly cholesterol stones. There were two false-negative diagnoses in patients with cholesterol calculi scanned at 1 cm intervals. Cholesterol stones are nearly isodense with bile and may be difficult to visualize in the common duct by routine scanning techniques. There are three suggestive CT features of cholesterol common duct calculi: (1) abrupt termination of the distal common bile duct without an obstructing mass, (2) a faint rim of increased density along the peripheral margin of a low-density calculus, and (3) mottled areas of increased density centrally within a calculus elevating its CT number above values for normal bile. Modification of scanning technique to obtain high-resolution images of the extrahepatic biliary tree is stressed to optimize visualization of the above findings.

Adult↗

Cyclic adenosine 3':5-monophosphate receptor proteins in hormone-dependent and -independent rat mammary tumors.

The molecular species of cyclic adenosine 3':5'-monophosphate (cAMP) receptor proteins (high-affinity-binding proteins) present in hormone-dependent and -independent rat mammary carcinomas were identified and characterized. Three major types of cAMP receptor proteins, with molecular weights of 39,000, 48,000, and 56,000, specifically incorporated the photoaffinity label, 8-azido-cyclic adenosine 3':5'-[32P]monophosphate and were identified by sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the tumor cytosols. The M.W. 48,000 and 56,000 receptor proteins appeared to be the regulatory subunits of cAMP-dependent protein kinase types I and II, respectively, and the M.W. 39,000 receptor protein was the proteolytic fragment of the M.W. 56,000 receptor protein. The relative amounts of these cAMP receptor proteins varied from one tumor type to another and showed no correlation with respect to the hormone dependency of tumors. Under two-dimensional gel electrophoresis, however, the M.W. 56,000 receptor protein from hormone-dependent tumors migrated as a doublet and shifted to either a more acidic or more basic charge than that of the receptor protein of hormone-dependent tumors. The alteration of the charge of the receptor did not affect the affinity for cAMP binding, because both hormone-dependent and hormone-independent tumor cytosols exhibited the dissociation constant for cAMP of approximately 10(-8) M. The M.W. 56,000 cAMP receptor protein from hormone-dependent tumors exhibited self-phosphorylation, but that from hormone-independent tumors did not. The diethylaminoethyl cellulose elution profiles of cAMP receptor proteins also differed between hormone-dependent and -independent tumors; cAMP binding activity from hormone-dependent tumors coeluted with cAMP-dependent protein kinase activity, whereas most of the cAMP binding activity from hormone-independent tumors eluted at a higher ionic strength than did cAMP-dependent protein kinase activity. These results suggest that the charge alteration of cAMP receptor proteins, which appears to occur at a site remote from that of cAMP binding, may be associated with the hormone independency of mammary tumors.

Affinity Labels↗