The immunocytochemical demonstration of copper-zinc superoxide dismutase in the brain.

Copper-zinc superoxide dismutase (CuZn-SOD) has been localized in formalin-fixed, paraffin-embedded sections of both canine and rat brains. Staining with an immunoenzyme bridge sequence revealed CuZn-SOD in all regions of the brains examined. Specific sites of localization included cerebral cortical pyramidal cells, cerebellar Purkinje cells, neurons in 'subcortical nuclei', and oligodendrocytes throughout the brain.

Mechanism of the protective activity of ICRF-187 against alloxan-induced diabetes in mice.

ICRF-187, (+)-1,2-bis(3,5-dioxopiperazine-1-yl)propane, has been shown to protect against alloxan diabetes (el-Hage et al., 1981). Since alloxan-induced pancreatic beta cell damage is thought to be mediated through the generation of highly reactive oxygen radicals by a metal catalyzed reaction involving both superoxide anion and hydrogen peroxide, in the present study the protective activity of ICRF-187 was compared with that of free radical scavengers, microsomal enzyme inhibitors and chelating agents.

Preservative cytotoxicity to cultured corneal epithelial cells.

Cultured human and rat corneal epithelial cells with 51Cr incorporated were used as a model to test the cytolytic action of four common preservatives. Benzalkonium chloride, chlorohexidine and thimerosol were all found to lyse greater than 40% cells when incubated for fifteen minutes at concentrations in clinical use in topical ophthalmic medications. Chlorobutanol is the only preservative tested which has a low level of cytotoxicity (10%) and which, under these conditions, can be considered a safe preservative using cytolytic activity as the means of criteria.

Effect of variation of retinal polyene side-chain length on formation and function of bacteriorhodopsin analogue pigments.

The effect of the length of the retinal polyene side chain on bacterioopsin pigment formation and function has been investigated with two series of synthetic retinal analogues. Cyclohexyl derivatives with polyene chains one carbon longer and one or more carbons shorter than retinal and linear polyenes with no ring have been synthesized and characterized. Compounds of six carbons or less in the polyene chain form pigments very poorly or not at all with bacterioopsin.

Imidazo[4,5-c]pyridines (3-deazapurines) and their nucleosides as immunosuppressive and antiinflammatory agents.

A variety of imidazo[4,5-c]pyridines (3-deazapurines) were synthesized. With use of these aglycons as pentosyl acceptors, the corresponding ribonucleosides and 2'-deoxyribonucleosides were prepared by an enzymatic method involving transfer of the pentosyl moiety from appropriate pyrimidine nucleosides. With most of the imidazo[4,5-c]pyridines, the products obtained from the enzyme-catalyzed reactions were pentosylated exclusively in the 1-position.

Neurospora crassa ribosomal DNA: sequence of internal transcribed spacer and comparison with N. intermedia and N. sitophila.

Using [32P]DNA probes from a clone containing 17S, 5.8S and 26S rRNA of Neurospora crassa, the remainder of the repeat unit (RU) for ribosomal DNA (rDNA) has been cloned. Combining restriction analysis of the cloned DNA and restriction digests of genomic DNA, the RU was found to be 8.

The protective role of copper-zinc superoxide dismutase against alloxan-induced diabetes: morphological aspects.

Copper-zinc superoxide dismutase is known to protect pancreatic beta-cell function from the damage of alloxan. A morphological investigation of copper-zinc superoxide dismutase prophylaxis against alloxan was undertaken in rats to investigate the mechanism of this protective action. Exogenous copper-zinc superoxide dismutase reproducibly protected the morphological features of pancreatic beta cells against damage by alloxan as determined by light microscopic immunostaining for insulin and by ultrastructural examination.

Immunolocalization of copper-zinc superoxide dismutase. II. Rat.

Copper-zinc superoxide dismutase (CuZn SOD) has been localized in formalin-fixed rat tissues. Staining with a modified immunoenzyme bridge technique using the avidin-biotin-peroxidase complex revealed abundant endogenous CuZn SOD in cells that function in transporting ions, either cellularly, as in the case of tracheal, bronchiolar, and colonic epithelial cells, gastric oxyntic cells, and cells lining the salivary ducts and proximal convoluted tubules in the nephron, or intracellularly, as exemplified by skeletal muscle and neurons. Additionally, the enzyme was consistently demonstrable in hepatocytes, endocrine cells of the islets of Langerhans, and the highly membranous oligodendrocytes in the central nervous system.

Canine retinal superoxide dismutase: identity with the erythrocyte enzyme.

Superoxide dismutase has been isolated from canine retina and compared to the commercial erythrocyte enzyme. The two enzymes have been characterized by biochemical and immunochemical methods. By the criteria used (enzymatic activity, immunoactivity, absorption spectra, electrophoretic properties, amino acid analyses and peptide maps), the two enzymes are completely homogeneous.

Localization of copper-zinc superoxide dismutase in the endocrine pancreas.

Immunoelectron microscopy and cellular fractionation on sucrose density gradients have been used to examine the intracellular distribution of copper-zinc superoxide dismutase (SOD) in the canine and rat endocrine pancreas. Using rabbit anti-canine copper-zinc SOD as the primary antiserum, immunostaining in canine beta and non-beta islet cells was significantly greater than that in serial sections of the same islet incubated with preimmune serum from the same rabbit. Within the cells, immunostaining was associated with spherical and crystalloid granules as well as with the cytoplasm.

The effect of age on corneal and lens superoxide dismutase.

The enzymatic activity of copper-zinc superoxide dismutase within the cornea and lens of the juvenile (1 week) and adult (26 week) rat has been measured relative to both total soluble protein and immunoreactive protein. Enzymatic activity of corneal superoxide dismutase, localized in the epithelium and endothelium, remains constant with age relative to total soluble protein and the ratio of catalytically active enzyme to immunoreactive enzyme is near unity indicating that the superoxide dismutase present is enzymatically active. Likewise, in the juvenile rat, the majority of lens superoxide dismutase, which is located in the capsule epithelium, is enzymatically active.

Meningioma with intracerebral hematoma.

A case of spontaneous intracranial hemorrhage associated with a meningioma is presented. Intracranial hemorrhage has been reported to be associated with meningioma in 45 cases. A comprehensive review of the subject is presented.

Genetic methods for the detection of microbial pathogens. Identification of enterotoxigenic Escherichia coli by DNA colony hybridization: collaborative study.

Enteropathogenic Escherichia coli strains may produce a cholera-like, heat-labile enterotoxin (LT) as a virulence factor. The gene that codes for LT can be purified by recombinant DNA techniques and used as a genetic probe for DNA hybridization. These probes detect enterotoxigenic strains as well as strains that may not manifest toxin production but carry the genetic information to do so.

The rnh gene is essential for growth of Escherichia coli.

We have determined that a functional gene coding for ribonuclease H seems to be essential for cell growth in Escherichia coli. A strain was made with two copies of the rnh gene by lysogenizing an E. coli strain with a lambda phage bearing a copy of the rnh gene.

Localization of corneal superoxide dismutase by biochemical and histocytochemical techniques.

Superoxide dismutase activity is found in the cornea of rats, dogs, rabbits and humans. A superoxide dismutase identical to the Cu-Zn enzyme is identified by biochemical and immunochemical methods in the corneal epithelium and endothelium in relative high abundance (90-100 U mg-1 protein). The enzyme quantities detected by radioimmune assay and bioactivity assay are similar, giving evidence that the enzyme present is biologically functional.

Cycloheptatrienylidene analog of 11-cis retinal. Formation of pigment in photoreceptor membranes.

In biochemical and electrophysiologic studies employing the bullfrog (Rana catesbeiana) and the rat, the authors examined the interaction of opsin and an 11-cis-locked analog of retinal. In previously bleached preparations of bullfrog receptor outer segments (ROS) and isolated retinas, incubation with the aldehyde form (I) of the analog leads to the appearance of a pigment that is degraded slowly by hydroxylamine but is relatively resistant to photolysis. In the ROS preparation, the analog pigment (lambda max of difference spectrum congruent to 497 nm) also forms on incubation with NADP+ and the alcohol form (II) of the analog.

Computer modeling of the recombination reaction of rhodopsin.

Various mechanistic schemes for the recombination reaction of rhodopsin were designed and tested using computer modeling and simulation with data from kinetics experiments. The reaction schemes were mathematically modeled by systems of nonlinear first-order ordinary differential equations (ODEs) with unknown rate constants. Each model was fitted to the experimental data by using a modified simplex algorithm for parameter (rate constant) estimation and Gear's method for solving stiff systems of ODEs.

Regeneration of rhodopsin and isorhodopsin in rod outer segment preparations: absence of effect of solvent parameters.

Regeneration of rhodopsin and isorhodopsin from bleached bovine rod outer segment suspensions and 11- or 9-cis retinal occurs at similar rates (second-order rate constants of 1000 M-1s-1 and 900 M-1s-1, respectively) and to a similar extent (maximal regeneration at pH 5.5-7.0).

The immunolocalization of copper-zinc superoxide dismutase in canine tissues.

Copper-zinc superoxide dismutase (CuZn SOD) has been localized in paraffin-embedded sections of formalin-fixed, canine tissues. Staining with the immunoenzyme bridge sequence and the technique utilizing avidin-biotin-peroxidase complex revealed high levels of CuZn SOD in a number of sites. These included hepatocytes, colonic absorptive epithelial cells, ciliated bronchiolar epithelial cells, cells lining the thick ascending limb of Henle's loop in the nephron, endocrine cells producing hormones in pancreatic islets, and neurons in several regions of the central nervous system.

Pharmacologic activities of copper compounds in chronic diseases.

Copper complexes have been shown to be effective antiinflammatory, antiulcer, anticonvulsant, anticancer, and antidiabetic agents. This seemingly diverse variety of pharmacologic effects is unified by the hypothesis that copper complexes facilitate or promote tissue repair processes involving copper-dependent enzymes and that arthritis, ulcers, seizures, neoplasia, and diabetes are diseases of specific tissues in disrepair. The corollary to this hypothesis is that the loss or reduction of copper-dependent enzyme-mediated processes leads to tissue dysfunction that may be reversed with copper complex therapy.

Attenuation of streptozotocin diabetes with superoxide dismutase-like copper(II)(3,5-diisopropylsalicylate)2 in the rat.

Experimental diabetes can be produced by agents with specific toxicity for pancreatic islet B cells. This effect has been reported to be modified both in vitro and in vivo by various radical scavengers including the enzyme superoxide dismutase. Copper(II)(3,5-diisopropylsalicylate)2 is lipophilic and possesses superoxide dismutase bioactivity.

Low levels of RNase H activity in Escherichia coli FB2 rnh result from a single-base change in the structural gene of RNase H.

The DNA coding for RNase H from a mutant strain of Escherichia coli (FB2) was cloned into plasmid pBR322. DNA sequence analysis and the exchange of a portion of the mutant and wild-type genes revealed that a single-base alteration (C-->T) in the coding region of the structural gene for RNase H is responsible for the difference in RNase H activity of the wild-type and mutant cells.