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Biomedical subjects

R E Reed

Publications and source records attributed to R E Reed.

At least 19 recordsLinked to original sources
PubMed1995

Neuroaxonal degeneration in sheep grazing Sorghum pastures.

During the fall of 1992, 250 (10%) of 2,500 Rambouilet cross feeder lambs grazing Sorghum bicolor developed neurologic signs including weakness, ataxia, head shaking, knuckling of the fetlocks, inability to rise, and opisthotonos. One hundred fifteen (46%) of the affected lambs died. Twenty of the surviving lambs exhibited residual neurologic signs of ataxia when stressed. At the same time, 275 (25%) of 1,100 ewes grazing a nearby sudex pasture (S. sudanese x S. bicolor) gave birth to lambs that were weak and unable to rise. Newborn lambs exhibited extensor rigidity and opisthotonos when assisted to a standing position. The dystocias that occurred were due to lambs with contracted limbs (arthrogryposis). All affected lambs died or were euthanized. Histologic examination of the brains of 3 feeder lambs and 9 newborn lambs revealed similar microscopic lesions. The predominant change was the presence of focal axonal enlargements (spheroids) in the proximal segments of axons, which were restricted to the nuclei of the medulla, cerebellum, and midbrain. In addition, the spinal cord contained spheroids in the ventral horn gray matter of the 6 newborns examined. Ultrastructurally, the spheroids were composed of aggregates of neurofilaments, mitochondria, vesicular bodies, and dense bodies bounded by a thin myelin sheath. There was mild gliosis in the more severely affected animals of both groups. There was minimal Wallerian degeneration in the white matter adjacent to affected nuclei in the brain and the ventromedial and dorsolateral funiculi of the spinal cord. This is the first detailed report of Sorghum toxicity in sheep.

Animal Feed↗
PubMed1991

Flavin-containing monooxygenase: a major detoxifying enzyme for the pyrrolizidine alkaloid senecionine in guinea pig tissues.

Evidence based on optimal pH, thermal stability, and enzyme inhibition data suggests that the NADPH-dependent microsomal N-oxidation of the pyrrolizidine alkaloid senecionine is carried out largely by flavin-containing monooxygenase in guinea pig liver, lung, and kidney. In contrast, the hepatic microsomal conversion of senecionine to the pyrrole metabolite (+/-)-6,7-dihydro-7-hydroxy-1-hydroxymethyl-5H-pyrrolizine (DHP) is catalyzed largely by cytochrome P450. However, the rate of senecionine N-oxide formation (detoxication) far exceeded the rate of DHP formation (activation) in guinea pig liver microsomes over a range of pHs (pH 6.8 to 9.8). In guinea pig lung and kidney microsomes, N-oxide was the major metabolite formed from senecionine with little or no production of DHP. The high rate of detoxication coupled with the low level of activation of senecionine in liver, lung, and kidney may help explain the apparent resistance of the guinea pig to intoxication by senecionine and other pyrrolizidine alkaloids.

Animals↗
PubMed1991

Canine distemper virus infection and encephalitis in javelinas (collared peccaries).

Canine distemper virus has been isolated in dog lymphocyte cultures from the brains of three javelinas that became moribund with signs of encephalitis. Canine distemper viral antigen was demonstrated predominantly in neurons and morbillivirus-like structures were seen by electron microscopy in brains of diseased animals. Serological studies suggest that CDV infection may be common in javelinas.

Animals↗
PubMed1985

Ocular coccidioidomycosis in a cat.

Enucleation of the right eye was performed on a 12-year-old male Persian cat when therapy for uveitis failed. Histologic examination of the anterior and posterior chambers and the vitreous led to a diagnosis of endophthalmitis caused by Coccidioides immitis infection. The primary focus of infection was not determined. Latex particle agglutination, agar gel immunodiffusion, and complement fixation gave negative results for Coccidioides immitis antibody.

Animals↗
PubMed1983

Repeated sequences and open reading frames in the 3' flanking region of the gene for the RNA subunit of Escherichia coli ribonuclease P.

We have determined the identity of about 700 nucleotides in the 3' flanking region of the gene for M1 RNA, the RNA component of RNase P (EC 3.1.26.5). This region begins with a 113-base-pair segment of DNA, which is repeated approximately 3.5 times. The first repeating unit originates within the gene sequence for the 3' end of mature M1 RNA. The repeating units are highly conserved but diverge considerably after the partial fourth repeat. Segments of sequence homologous to the repeats have been identified both upstream in the M1 RNA transcription unit and downstream from the repeating units. Several overlapping open reading frames, with the potential to encode small basic proteins, have been identified in the repeated sequences. The structure of the M1 RNA gene 3' flanking region is very similar to the corresponding region at the Tyr T locus. In vitro and in vivo, transcription of the M1 RNA gene appears to terminate about 40 nucleotides downstream from the 3' terminus of mature M1 RNA. Therefore, an RNA processing event is involved in the biosynthesis of M1 RNA.

Base Sequence↗
PubMed1983

Leptospirosis in rodents from an arid environment.

Rodents (n = 358) were trapped from 6 locations in Arizona, including 2 dairies, 2 swine raising operations, and 2 areas where domestic animal access was limited. Isolates of Leptospira interrogans serovar ballum were obtained from 3 house mice (Mus musculus) trapped in dairies. Leptospira were seen in silver-stained kidney sections of 10.4% of the rodents. The usefulness of serologic data in detecting leptospiral infection in these rodents was uncertain because so few animals yielded isolates that valid comparisons of culture positives to serologic positives were not possible. Titers greater than or equal to 1:160 were obtained to serovars autumnalis, ballum, bratislava, canicola, grippotyphosa, hardjo, icterohaemorrhagiae, and pomona. Nearly 60% of the rodents had microscopic lesions in kidneys, including 20 of 34 (59%) of those in which leptospira were seen.

Animals↗
PubMed1982

Nucleotide sequence of the gene encoding the RNA subunit (M1 RNA) of ribonuclease P from Escherichia coli.

The gene encoding the RNA subunit (M1 RNA) of RNAase P (EC 3.1.26.5) from Escherichia coli has been isolated, and its complete nucleotide sequence, including flanking regions, has been determined. The promoter region, similar to others near genes under stringent control, and the site of transcription termination have been identified. The transcript from the gene (M1 RNA) can be drawn in a secondary structure that has approximately 60% G-C base pairs. One hairpin loop of this hypothetical structure has five contiguous nucleotides complementary to invariant nucleotides in the TpsiCG loop of all E. coli tRNAs. The M1 gene, when subcloned in the plasmid pBR325, can be amplified. It directs production of functional M1 RNA. In an E. coli strain thermosensitive for RNAase P function, the size of the gene transcript is the same as in wild-type E. coli, but less mature M1 RNA is made in the mutant cells.

Base Sequence↗
PubMed1980

Polycythemia vera and agnogenic myeloid metaplasia.

Age complications bring these patients to primary physicians more frequently than would be expected from incidence or prevalence statistics alone. Therapy is symptomatic. Termination in acute leukemia occurs in both conditions and the risk may be increased by radiation or myelosuppressive drugs. Careful management can prolong survival in polycythemia vera and improve the quality of life in both conditions.

Alkylating Agents↗
PubMed1977

Lipogenesis and the synthesis and secretion of very low density lipoprotein by avian liver cells in nonproliferating monolayer culture. Hormonal effects.

The nonproliferating chicken liver cell culture system described yields cell monolayers with morphological and lipogenic properties characteristic of the physiological-nutritional state of donor animals. Synthesis and secretion of fatty acid, cholesterol, and very low density lipoprotein (VLDL) occur at in vivo rates and respond to hormones and agents which affect these processes in vivo. Cells derived from fed chickens maintain high rates of synthesis of fatty acid and cholesterol for several days if insulin is present in the medium. High rates of fatty acid synthesis are correlated with the appearance of membrane-enclosed triglyceride-rich vesicles in the cytoplasm; deletion of insulin causes a decrease (T1/2 = 22 h) in fatty acid synthetic activity. Addition of glucagon or cyclic AMP (cAMP) causes an immediate cessation of fatty acid synthesis and blocks the appearance of the triglyceride-rich vesicles. Fatty acid synthesis in liver cells prepared from fasted chickens is less than 5% that of cells from fed animals. After 2-3 days in culture with serum-free medium containing insulin +/- triiodothyronine, fatty acid synthesis is restored to normal; glucagon or dibutyryl cAMP blocks this recovery. Liver cells derived from estradiol-treated chickens synthesize and secrete VLDL for at least 48 h in culture. Electron micrographs of these cells reveal more extensive development of the rough endoplasmic reticulum and Golgi complex compared to cells from untreated chickens. Whereas [3H]leucine incorporation into total protein is unaffected by estrogen treatment, [3H]leucine incorporation into cellular and secreted immunoprecipitable VLDL is markedly increased indicating specific activation of VLDL apopeptide synthesis; 8-10% of the labeled protein synthesized and secreted is VLDL. Dodecyl sulfate-acrylamide gel electrophoresis of immunoprecipitated 3H-VLDL reveals three major apopepetides of 300,000, 11,000, and 8,000 daltons corresponding to those of purified chicken VLDL.

Bucladesine↗
PubMed1977

Ankylosing spondylitis with selective IgA deficiency and a circulating anticoagulant.

A patient with ankylosing spondylitis was found to have selective IgA deficiency and a non-heparin, immediate-acting antithrombin (antithrombin V). T cells were decreased, and serum IgG was increased. In vitro synthesis of IgG by peripheral blood lymphocytes was very high. This association of ankylosing spondylitis with the T cell and protein abnormalities is probably fortuitous but does demonstrate that severe spondylitis may evolve in the absence of IgA.

Antithrombins↗
PubMed1975

Partial purification and characterization of aspartate aminotransferases from seedling oat leaves.

As relatively little information is available on the properties of aspartate aminotransferase from photosynthetic tissue, isolation and characterization of the two major electrophoretically distinct forms of this enzyme from seedling oat leaf homogenates were undertaken. These two forms are designated I for the more anionic form and II for the less anionic form. Form I, 80 to 90% of the total activity, has been purified to a specific activity of 120 mumol/min/mg of protein (1100-fold) and is estimated to be 90 to 95% homogeneous, as judged by analytical polyacrylamide gel electrophoresis. Form II, 10 to 20% of the total activity, has been purified to a specific activity of approximately 6 mumol/min/mg of protein (300-fold). Both forms exhibit optimal activity at pH 7.5. Michaelis constants do not differ greatly between forms I and II and are similar to those reported for the pig heart cytosolic enzyme as well as aspartate aminotransferase from other plant sources. A molecular weight of 130,000 for the purified aspartate aminotransferase I was estimated by sedimentation equilibrium centrifugation; molecular weights of the two forms are similar as estimated by sucrose density gradient centrifugation. No activation by pyridoxal phosphate has been observed during purification.

Aspartate Aminotransferases↗