Studies on ethanol-inducible cytochrome P-450 in rabbit liver, lungs and kidneys.
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Animals↗
Biomedical subjects
H Miller
Publications and source records attributed to H Miller.
Characterization of a cDNA clone coding for a sea urchin histone H2A variant related to the H2A.F/Z histone protein in vertebrates.
A cDNA clone coding for a sea urchin histone H2A variant has been isolated. The coding region of the clone has been sequenced and the sequence found to be closely related to the H2A.F sequence in chickens. The nucleotide sequence of the sea urchin H2A.F/Z is 74% conserved when compared to chicken H2A.F and 51% conserved compared to sea urchin H2A early and 60% compared to sea urchin H2A late. The nucleotide-derived amino acid comparisons show that H2A.F/Z is 97% homologous with H2A.F in chickens and 57% and 56% homologous when compared to sea urchin H2A early and late respectively. There are between 3-6 copies of the H2A.F/Z sequence in the S. purpuratus genome. The H2A.F/Z gene sequence codes for the previously identified H2A.Z protein. All embryonic stages and adult tissues tested contain mRNA for H2A.F/Z. The mRNA appears in the poly A+ RNA fraction after chromatography over oligo dT cellulose.
Age Factors↗
Practical aspects of preparing phage and plasmid DNA: growth, maintenance, and storage of bacteria and bacteriophage.
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Bacteriophage lambda↗
Vitreoretinal junction in infectious endophthalmitis in a primate eye.
A primate eye affected by postoperative infectious endophthalmitis was studied early in the course of the disease. Retinal perivasculitis, vitreoretinal adhesions along the inflamed vessels, and traction of the partially separated posterior vitreous on the retina at the adhesion sites were observed. It is suggested that such vitreoretinal junction pathology may be responsible for the development of retinal detachment in infectious endophthalmitis.
Animals↗
Idiopathic ventricular fibrillation: inducibility and beneficial effects of class I antiarrhythmic agents.
Ventricular fibrillation in patients without recognizable heart disease is uncommon and electrophysiologic data on such patients is limited. Over a 7 year period, five patients (three men and two women, ranging in age from 24 to 52 years) without demonstrable heart disease underwent electrophysiologic studies with pharmacologic drug testing because of single (four patients) or multiple (one patient) documented episodes of ventricular fibrillation. The arrhythmic event was unrelated to myocardial ischemia or infarction, metabolic or electrolyte disturbances, drug toxicity, preexcitation, or prolonged QT syndromes. In all three patients receiving no antiarrhythmic drugs and in two pretreated with amiodarone, a rapid poorly tolerated ventricular tachyarrhythmia requiring cardioversion was induced by programmed ventricular stimulation with up to two extrastimuli. In all instances, addition of either oral quinidine or oral disopyramide prevented the induction of sustained ventricular arrhythmias. All five patients were placed on antiarrhythmic drug regimens found effective during electrophysiologic studies and remained asymptomatic during follow-up periods ranging from 12 to 93 (mean 52) months. We conclude that in the patients with idiopathic ventricular fibrillation in our study: programmed ventricular stimulation reliably replicated the spontaneous arrhythmia, class I antiarrhythmic agents effectively prevented induction of the arrhythmia in the laboratory, and in contrast to the severity of the presenting arrhythmia, a benign clinical course was observed during long-term therapy with class I antiarrhythmic agents.
Adult↗
Surgical revascularization following failed percutaneous transluminal coronary angioplasty.
Percutaneous transluminal coronary angioplasty (PTCA) was performed on 200 patients and failed in 36, 12 of whom underwent myocardial revascularization within 3 hours after the angioplasty attempt. Elective operations were performed without complications in the other 24 cases. The 12 emergency operations were necessitated by major complications during or after PTCA, viz, coronary occlusion (6 patients) coronary dissection (2) and failed catheter passage or dilation with severe myocardial ischemia (4). Three of these 12 patients had signs of acute myocardial infarction preoperatively, and new infarction appeared postoperatively in two cases. All eight patients with ST-segment elevation preoperatively had raised levels of myocardial enzymes postoperatively, and two of them had new Q-waves. Three of the 12 patients required inotropic drugs following revascularization. There was one postoperative death. When complications arise in PTCA, emergency operation should be undertaken. When PTCA fails, but without complications, surgery can be electively performed.
Aged↗
Morphologic observations on experimental subretinal neovascularization in the monkey.
Subretinal neovascularization is a poorly understood and potentially disastrous feature of many eye diseases. We used light and electron microscopy to study the sequence of events that lead to the formation of new vessels after laser photocoagulation of the retina and choroid of primates. In this animal model there is a rapid development of new blood vessels; one day after photocoagulation, endothelial cell degeneration and thrombus formation were observed in the capillaries, venules and arterioles of the choroid around the center of the lesion. Re-endothelialization began in some thrombosed choroidal vessels, with migration of the activated endothelial cells within the old basement membrane. Two days after photocoagulation, re-endothelialization was observed in almost all thrombosed choroidal vessels, and the initial stage of the endothelial cell budding was observed in the pre-existing choroidal vessels; this was especially prominent in venules with pericytes. Three days after photocoagulation, not only the endothelial cells in pre-existing vessels but also those in re-endothelialized vessels showed budding and lumen formation. The lumen of vessels was formed by the budding of adjacent endothelial cells that were coupled by transient intercellular junctions. Mitotic figures were frequently found in the endothelial cells distal to the growing tip. Five to eight days after photocoagulation, many new vessels extended into the subretinal space.
Animals↗
Severe hypertension with absent secondary sex characteristics due to partial deficiency of steroid 17 alpha-hydroxylase activity.
A genotypically female patient with 17 alpha-hydroxylase deficiency, and typical symptoms of hypertension, hypokalaemia and lack of secondary sex characteristics, is described. Plasma 17 alpha-hydroxycorticosteroid levels (cortisol, 11-deoxycortisol) and oestradiol were low. Those of 11-deoxycorticosterone, corticosterone, their 18-hydroxy- derivatives, ACTH and gonadotrophins were high and, with the exception of the gonadotrophins, suppressed to normal with dexamethasone which also corrected blood pressure (BP) and electrolyte abnormalities. Plasma aldosterone levels, initially suppressed, increased during treatment but, at 3 months, showed some signs of subnormal responsiveness. Possible reasons for this are discussed. The patient remains well after 9 years on dexamethasone and oestrogen therapy.
Adrenal Cortex Hormones↗
Preparation and characterization of monoclonal antibodies to pregnenolone 16-alpha-carbonitrile inducible rat liver cytochrome P-450.
Hybridomas were prepared from mouse myeloma cells and spleen cells derived from BALB/c female mice immunized with purified rat hepatic pregnenolone 16-alpha-carbonitrile (PCN) induced cytochrome P-450 2a/PCN-E. The monoclonal antibodies (MAbs) thus obtained were screened for binding to the purified P-450 2a/PCN-E by radioimmunoassay. Eleven independent hybrid clones produced MAbs, each of which was of a single mouse immunoglobulin subclass of the IgG1, IgG2a or IgG2b type. Each of the MAbs produced by the eleven individual hybrid clones bound strongly to P-450 2a/PCN-E as assessed by radioimmunoassay and immunoprecipitation of P-450 2a/PCN-E in Ouchterlony double-immunodiffusion plates. Of the eleven MAbs, three also bound strongly to the phenobarbital-inducible rat liver cytochrome P-450 PB-4. Thus, two classes of MAbs were obtained, one class specific for P-450 2a/PCN-E and a second class that bound to both PCN- and phenobarbital-inducible P-450 forms. The reactivities of one MAb from each class toward eight highly purified rat hepatic cytochromes P-450 were examined using solid phase enzyme-linked immunosorbent analyses. The MAb designated C2 was found to be specific for P-450 2a/PCN-E and did not cross-react with seven other P-450 forms. This MAb was shown to be an effective probe for monitoring, by Western blotting, the induction of microsomal P-450 2a/PCN-E by PCN and phenobarbital. The MAb designated C1 reacted both with P-450 2a/PCN-E and with the two major phenobarbital-inducible P-450 forms, PB-4 and PB-5. None of the MAbs was inhibitory towards P-450 2a/PCN-E-dependent aryl hydrocarbon hydroxylase, benzphetamine N-demethylase, ethoxycoumarin O-deethylase or ethymorphine N-demethylase activity, indicating that the epitopes recognized by these MAbs are not directly associated with catalytic activity. The strong reactivities of three of the MAbs with both P-450 2a/PCN-E and P-450s PB-4 and PB-5 indicate that these two structurally quite different cytochrome P-450 families share at least one common epitope. These new MAbs are additions to our library of MAbs to different cytochromes P-450 and should help further our understanding of the relationship of cytochrome P-450 phenotype and multiplicity to inter-individual differences in drug and carcinogen metabolism and sensitivity.
7-Alkoxycoumarin O-Dealkylase↗
Experimental epiretinal proliferation induced by intravitreal red blood cells.
We describe a reproducible animal model of epiretinal proliferation, based on intravitreal injection of red blood cells, that closely simulates the more benign proliferative extraretinopathies. Using light microscopy and scanning and transmission electron microscopy, we monitored the development and behavior of the experimental epiretinal membranes. We found breaks in the integrity of the retinal surface through which glial cells migrated onto the retina, proliferated into thick epiretinal tissue, and contracted to cause retinal pucker. All these steps were associated with the chronic inflammatory response to the long-lasting presence of red blood cells in the vitreous. Thus, the development of epiretinal membranes requires continuous intraocular stimulation in addition to a break in retinal integrity.
Animals↗
Retinal wound healing. Cellular activity at the vitreoretinal interface.
Cellular activity at the vitreoretinal interface after full-thickness retinal wounds was studied in rabbit eyes, using light and electron microscopy. Glial cell extensions grew initially on the retinal surface around the wound site. This brief period of glial proliferation was associated with the posttraumatic inflammatory response and, more specifically, with phagocytic monocyte accumulation at the vitreoretinal interface. Once the inflammation subsided, this abortive attempt to grow membranes on the retinal surface stopped and true epiretinal membranes did not develop. Our observations suggest that intraocular inflammation and macrophage response determine the extent of healing and scarring on an injured retinal surface, and thus may play a key role in the pathogenesis of epiretinal membranes.
Animals↗
Effect of the vitreous on retinal wound-healing.
The healing process of experimental retinal wounds in nonvitrectomized and vitrectomized rabbit eyes was compared. Using light, transmission and scanning electron microscopy, a significant difference was observed at the late stages of the healing process. The retinal wounds in the nonvitrectomized eyes healed properly, forming regular and smooth scars, while the scars that developed in the vitrectomized eyes were irregular and hypertrophic. Our observations suggest that the vitreous plays a role in normal healing of retinal wounds.
Animals↗
Monoclonal antibodies to liver microsomal cytochrome P-450E of the marine fish Stenotomus chrysops (scup): cross reactivity with 3-methylcholanthrene induced rat cytochrome P-450.
Hybridomas were prepared from myeloma cells and spleen cells of BALB/c female mice immunized with hepatic cytochrome P-450E purified from the marine fish, Stenotomus chrysops (scup). Nine independent hybrid clones produced MAbs, either IgG1, IgG2b, or IgM, that bound to purified cytochrome P-450E in radioimmunoassay. Antibodies from one clone MAb (1-12-3), also strongly recognized rat cytochrome P-450MC-B (P-450BNF-B; P-450c). The nine antibodies inhibited reconstituted aryl hydrocarbon hydroxylase (AHH) and ethoxycoumarin O-deethylase of scup cytochrome P-450E to varying degrees, and inhibited AHH activity of beta-naphthoflavone-induced scup liver microsomes in a pattern similar to that in reconstitutions, indicating that cytochrome P-450E is identical to the AHH catalyst induced in this fish by beta-naphthoflavone. MAb 1-12-3 also inhibited the reconstituted AHH activity of the major BNF-induced rat isozyme. Conversely, MAb 1-7-1 to rat cytochrome P-450MC-B had little effect on AHH activity of scup cytochrome P-450E, and did not recognize cytochrome P-450E in radioimmunoassay nor in an immunoblot. Scup cytochrome P-450E and rat cytochrome P-450MC-B thus have at least one common epitope recognized by MAb 1-12-3, but the epitope recognized by Mab 1-7-1 is absent or recognized with low affinity in cytochrome P-450E. The various assays indicate that the nine MAbs against cytochrome P-450E are directed to different epitopes of the molecule. These MAbs should be useful in determining phylogenetic relationships of the BNF- or MC-inducible isozymes and their regulation by other environmental factors.
Animals↗
Keeping air out of i.v. lines.
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Embolism, Air↗
Interrelationship between Cd, Zn, insulin and phosphoglucomutase.
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Animals↗
Competitive bidding for hospital services.
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Blue Cross Blue Shield Insurance Plans↗
Newly-formed subretinal vessels. Fine structure and fluorescein leakage.
The ultrastructure of experimentally induced newly formed subretinal vessels was correlated with the amount of fluorescein leakage demonstrated by the neovascular membranes during angiography. The membranes that demonstrated leakage contained subretinal vessels with a fenestrated endothelial wall and intermediate interendothelial cell junctions. As these subretinal plexi matured, they stopped demonstrating leakage. This involution process was accompanied by the formation of focal interendothelial tight junctions; however, loss of fenestrations was not observed. The membranes that never demonstrated fluorescein leakage also contained fenestrated subretinal vessels at both early and late stages of development; and their interendothelial junctions showed similar maturation from open to focal tight junctions. Thus all subretinal vessels had "leaky" morphology strongly resembling that of the normal choriocapillaris, whether they demonstrated fluorescein leakage or not. The authors conclude that newly formed subretinal vessels retain the characteristics of the choriocapillaris from which they are believed to proliferate; they have the potential to leak fluorescein at all stages of their development. The absence of fluorescein leakage during angiography cannot always be correlated with the absence of "leaky" morphology.
Animals↗