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Biomedical subjects

H Miller

Publications and source records attributed to H Miller.

At least 19 recordsLinked to original sources
PubMed1992

New monoclonal antibodies for the detection of immediate early antigens of cytomegalovirus.

Two new monoclonal antibodies, CIE-1 and CIE-2, were developed for the rapid detection of human cytomegalovirus (HCMV) infection. They were found to be reactive with immediate early protein of HCMV in the nuclei of infected fibroblasts, as early as 3 hours post-infection. By radioimmunoprecipitation, CIE-1 was found to react with a protein with an apparent molecular weight of 70,000, whereas CIE-2 precipitated 2 proteins of 70,000 and 72,000 daltons, respectively. Both monoclonal antibodies recognized three prototype strains of HCMV: AD-169, Towne, and Davis, and did not cross-react with other human herpesviruses. CIE-1 and CIE-2 were compared with four commercial anti-HCMV monoclonal antibodies (Clonab, Dupont, Sera-Lab and Syva) by testing 88 clinical isolates. Culture confirmation tests and shell vial assays showed that CIE-1 and CIE-2 were more sensitive than several of these reagents and equally sensitive to the Dupont reagent. Moreover, CIE-1 and CIE-2 produced a bright, sharp staining of the nuclei of infected cells. These monoclonal antibodies should thus be valuable in rapid diagnosis of HCMV.

Animals↗
PubMed1992

Intraosseous infusion of resuscitative fluids and drugs: long-term effect on linear bone growth in pigs.

We studied the effects of intraosseous (IO) infusion of a standard fluid bolus and resuscitative drugs on long-term bone growth and epiphyseal closure in the "pediatric" swine model. Eighteen weanling pigs were randomly assigned to six groups as follows: three animals received two normal saline boluses, 20 mL/kg IO over 20 minutes; three received sodium bicarbonate, 1 mEq/kg IO; three received a 10% sodium bicarbonate infusion IO at maintenance rate over 1 hour; three received epinephrine 1:10,000, 0.1 mL/kg IO; three received an epinephrine infusion IO at 1 microgram/kg/min for 1 hour; and three received a dopamine infusion IO at 10 micrograms/kg/min for 1 hour. All infusions were given in the left hindleg; the right hindleg was used as a control. Lateral radiographs of the hind extremities were obtained at the beginning of the study and at 1 and 3 months after infusion. Linear radiographic measurements of the infused and control tibias were compared. At 6 months after infusion, the tibias were harvested, measured directly, and radiographed to determine the degree of epiphyseal closure. Analysis of variance for the first 3 months' data yielded a nonsignificant time-by-treatment interaction (P = .84) and a nonsignificant main effect for time (P = .22). Separate analysis of the direct measurements taken at 6 months revealed no difference in growth between experimental and control tibias. In addition, no radiographic difference in epiphyseal closure was noted between the two groups at the conclusion of the study, nor were any structural defects discovered. Intraosseous infusion of fluids and resuscitative drugs does not adversely affect subsequent bone growth and development in the swine model.

Animals↗
PubMed1991

Peroxide modification of monoalkylated glutathione reductase. Stabilization of an active-site cysteine-sulfenic acid.

Hydrogen peroxide reacts with two-electron reduced glutathione reductase (GR EH2 species) to give the native oxidized enzyme (E) without detectable intermediates. Prior alkylation of the EH2 interchange thiol with iodoacetamide, however, dramatically changes both the course and overall rate of the peroxide reaction. This oxidation, monitored spectrally, is characterized by an intermediate (EHRint) with enhanced long wavelength absorbance extending to 800 nm. This species decays in a second peroxide-dependent phase to an enzyme form (EHRox) easily distinguished from E. Quenching experiments with catalase allow the isolation of a stable mixture consisting of 36% monoalkylated GR (EHR), 60% EHRint, and 4% EHRox; NADPH titration and anaerobic dithiothreitol addition lead to quantitative reduction of EHRint to EHR, and there is an increase in thiol titer of 0.8-SH/FAD on NADPH reduction. Of the four titratable thiols present in EHR, 2.7 are lost on oxidation to EHRox and 0.7-0.8 mol of cysteic acid/FAD is formed. On the basis of these and other observations, we conclude that alkylation of the EH2 interchange thiol, which blocks disulfide formation, allows peroxide reaction at the remaining charge-transfer thiol to proceed via a stabilized cysteine-sulfenic acid intermediate (EHRint), which undergoes further oxidation to the corresponding cysteic acid (EHRox).

Alkylation↗
PubMed1991

Isradipine: overall clinical experience in hypertension in the United States.

Isradipine is a new dihydropyridine calcium antagonist shown to be efficacious, safe, and well tolerated in the treatment of hypertension, regardless of patient age or race. There has been no evidence of negative inotropism, atrioventricular conduction delay, nor clinically significant changes in laboratory parameters associated with isradipine treatment. A total of 934 patients have been treated with isradipine in double-blind hypertension trials (involving 297 patients treated with placebo and 414 treated with active controls, such as hydrochlorothiazide and enalapril). Both the mean changes from baseline in diastolic and systolic blood pressures and the percentage of patients responding to treatment (blood pressure decrease of at least 10 mm Hg) were greater with isradipine than with placebo or active controls. Blood pressure response increases with increases in isradipine dose up to 10 to 15 mg daily; higher doses do not, on average, result in greater blood pressure reduction. The incidence of adverse reactions with isradipine is similar to that for active controls and slightly more than for placebo. There were fewer discontinuations with isradipine and, in addition, a decrease in the incidence of new adverse reactions with increasing duration of treatment, down to 1% at 24 months.

Antihypertensive Agents↗
PubMed1991

Prospective study of cytomegalovirus antigenemia in allograft recipients.

A recently published technique for direct detection of cytomegalovirus (CMV) antigenemia was tested prospectively in 27 transplant recipients. Eighteen patients developed active CMV infections and 10 of the 18 experienced CMV syndrome. All of the infections were detected by classical virus isolation and/or serologic techniques. No antigenemia was demonstrated.

Antigens, Viral↗
PubMed1991

Comparison of immunofluorescence and enzyme immunoassay for detection of measles-specific immunoglobulin M antibody.

During a measles outbreak, 283 serum specimens from 221 suspected cases of measles were tested by immunofluorescence and enzyme immunoassay for the presence of measles-specific immunoglobulin M (IgM) antibodies by using commercially available reagents. There was 97% agreement between the two assays; thus, the choice of the method for diagnostic testing is a matter of convenience and experience. In all 62 cases of measles from which a single blood sample was available, measles IgM-specific antibodies were detectable by both methods. Fifty percent of the 62 cases were positive within 3 days after onset of the rash. This increased to 91% 10 days after onset of the rash.

Adolescent↗
PubMed1991

Blunt liver trauma at sunnybrook Medical Centre: a 13 year experience.

Between June 1, 1976 and June 30, 1989 The Regional Trauma Unit at Sunnybrook Medical Centre in Toronto, Ontario, Canada received 3730 patients. Of these 335 (9%) sustained a liver injury, 95% being due to blunt trauma. Open peritoneal lavage was performed on 80% of liver trauma patients (267/335), 99% being true positive. A laparotomy was performed on 97% of patients (324/335). Major surgical treatment was required in 132 patients (41%) and minor treatment in 192 patients (59%). The remaining 11 patients were treated conservatively (n = 3) or died during resuscitation (n = 8). Morbidity directly related to the liver injury was seen in 29 of 249 surviving patients (11%) although overall morbidity was 27% (67/249). Reoperation was required in 6% (14/249) with abscess or hematoma accounting for 11 of 14 operations. The overall mortality rate was 26% (86/335). Eighty two percent of patients (n = 276) had a grade I, II or III liver trauma according to Moore's classification with a mortality of 12% (n = 32). The remaining 18% of patients (n = 59) had a grade IV or V liver trauma with a mortality of 44% (n = 26). Of the 86 deaths, head injury accounted for 48 (56% of deaths); liver hemorrhage for 17 (20%), liver sepsis for 1 (1%) and other causes for 20 deaths (23%). Thus death due to the liver injury itself (hemorrhage and sepsis) occurred in 18 out of 335 patients (5% overall). Head injury accounted for the death of 48 out of 335 patients (14% overall). Over the past 13 years a trend has occurred at our institution whereby we are seeing less liver trauma in our population of multiply injured patients from 12% (1976-1983) down to 7% (1985-1989); with a gradual decline in overall mortality from 32% (1976-1983) to 19% (1985-1989), whereas the percentage of deaths due to head injuries and liver injury have increased.

Cause of Death↗
PubMed1990

Heterogeneity among the flavin-containing NADH peroxidases of group D streptococci. Analysis of the enzyme from Streptococcus faecalis ATCC 9790.

Polyclonal antisera prepared against the purified NADH peroxidase from Streptococcus faecalis ATCC 9790 (Enterococcus hirae) do not cross-react with the ATCC 11700 enzyme. Comparative tryptic maps of the two proteins indicate that the differences in primary structures extend beyond those localized to respective antigenic epitopes. Alignments of the NH2-terminal and active-site cysteinyl peptide sequences of the two streptococcal peroxidases reveal identities of 50 and 67% in the respective overlap regions. Dithionite titrations of the ATCC 9790 enzyme reveal a separation in potentials (E2 - E1) for the nonflavin and flavin redox centers of 39 mV, a value nearly 50 mV lower than that observed with the ATCC 11700 peroxidase. Despite these changes in redox behavior NADH titrations of the ATCC 9790 enzyme give rise to both EH2 and EH2.NADH species as previously observed. The enzyme turnover number with hydrogen peroxide is approximately 60% that of the ATCC 11700 peroxidase; the ATCC 9790 peroxidase is also inhibited during turnover with ethyl hydroperoxide. These findings suggest that the flavoprotein NADH peroxidases may exhibit greater diversity among the group D streptococci than previously observed with the widely distributed enzymes of the related flavoprotein disulfide reductase class.

Amino Acid Sequence↗
PubMed1990

Synthetic peptide antigens elicit monoclonal and polyclonal antibodies to cytochrome P450 IA2.

Two peptide sequences from cytochrome P450 IA2 were synthesized, coupled to ovalbumin and used as antigens to generate anti-peptide monoclonal and polyclonal antibodies. Antisera to both peptides reacted with rat IA2 but not the structurally similar IA1 form as determined by enzyme-linked immunosorbent assay. However, antisera to both peptides detected both rat IA2 and IA1 on immunoblots. In addition immunoblots of human liver microsomes revealed that both antisera recognized human IA2, but not IA1. Monoclonal antibodies generated against one of the peptides recognized rat IA2 and IA1 but did not detect human IA2. These results demonstrate the utility of anti-peptide antisera as a practical approach for the generation of P450 specific antibodies.

Amino Acid Sequence↗
PubMed1990

Variation in inducibility of cytochrome P-450c and aryl hydrocarbon hydroxylase in rat liver, lung, kidney, pancreas and nasopharynx.

The effect of 3-methylcholanthrene (MC) treatment on the cytochrome P-450c content of various rat tissues was examined by measuring the level of immunodetectable P-450c in conjunction with its aryl hydrocarbon hydroxylase (AHH) activity. Immunoblots revealed that P-450d was induced in the nasopharynx and pancreas in addition to its previously reported induction in the liver, lung and kidney. In contrast to P-450c, induction of the immunorelated P-450d was observed only in the liver. The specific content of immunodetected P-450c in the tissue homogenates decreased in the order: liver, nasopharynx, pancreas, lung, kidney. The corresponding AHH activities decreased in the order: liver, kidney, lung, nasopharynx, pancreas. The ratio of AHH activity to P-450c content varied widely among tissues: ratios of 37.2:1.7:0.47:0.04:0.02 were obtained for the kidney, liver, lung, nasopharynx and pancreas, respectively. The absence of a direct relationship between the levels of AHH and P-450c indicates that the extrahepatic activity may partially derive from P-450 forms other than P-450c and/or the specific activity of P-450c varies among different tissues.

Animals↗
PubMed1990

Pathogenesis of laser-induced choroidal subretinal neovascularization.

The early stages (1 day to 3 weeks) in the development of laser-induced choroidal subretinal neovascularization were studied in the monkey eye. Histopathology revealed that the intense laser beam disrupted the choroid/Bruch's membrane/retinal pigment epithelium (RPE) complex and initiated a repair process. Although all lesions received the same energy density, the initial choroidal wound varied among the lesions: in some, the necrotic choroid was surrounded by hemorrhagic retinal detachment with RPE denudation; in others, the necrotic choroid was surrounded only by minimal damage to the RPE monolayer. Formation of the choroidal wound was followed by an inflammatory response. Later, newly formed choroidal tissue filled the wound and continued to proliferate towards the subretinal space. RPE cells from the edges of the wound proliferated over the newly formed subretinal tissue and closed the wound. In lesions with a large area of damaged RPE, coverage of the wound was slow; fluid accumulated in the subretinal space, and the lesions demonstrated pooling of fluorescein on angiography (leaky lesions). In lesions with minimal damage to RPE monolayer, closure of the wound was rapid, and the proliferating choroidal tissue did not reach the subretinal space. There was no subretinal fluid accumulation and no pooling of fluorescein on angiography (nonleaky lesions). Our results indicate that both the amount of damage of the choroid/Bruch's membrane/RPE complex and the ability of RPE cells around the damaged area to proliferate and restore the continuity of the RPE layer determine the evolution of newly formed choroidal fibrovascular tissue into a subretinal membrane with or without pooling.

Animals↗
PubMed1990

Isradipine: overall clinical experience in hypertension in the United States.

Isradipine is a new dihydropyridine calcium antagonist shown to be efficacious, safe, and well tolerated in the treatment of hypertension, regardless of patient age or race. There has been no evidence of negative inotropism, atrioventricular conduction delay, nor clinically significant changes in laboratory parameters associated with isradipine treatment. A total of 934 patients have been treated with isradipine in double-blind hypertension trials (involving 297 patients treated with placebo and 414 treated with active controls, such as hydrochlorothiazide and enalapril). Both the mean changes from baseline in diastolic and systolic blood pressures and the percentage of patients responding to treatment (blood pressure decrease of at least 10 mm Hg) were greater with isradipine than with placebo or active controls. Blood pressure response increases with increases in isradipine dose up to 10-15 mg daily; higher doses do not, on average, result in greater blood pressure reduction. The incidence of adverse reactions with isradipine is similar to that for active controls and slightly more than for placebo. There were fewer discontinuations with isradipine and, in addition, the incidence of new adverse reactions decreased with increasing duration of treatment, down to 1% at 24 months.

Calcium Channel Blockers↗
PubMed1989

Induction of rat liver microsomal and nuclear cytochrome P-450 by dietary 2-acetylaminofluorene and butylated hydroxytoluene.

The influence of dietary 2-acetylaminofluorene (AAF) on the cytochrome P-450 content of rat liver microsomal and nuclear fractions was immunochemically probed with monoclonal and polyclonal antibodies to cytochromes P-450c and P-450d. Cytochrome P-450d but not P-450c was immunodetected in microsomes, nuclear envelopes, and nuclei from untreated rats. The levels of both cytochromes P-450c and P-450d were elevated after a diet of either 0.1% AAF for 1 week or 0.05% AAF for 3 weeks. However, the level of cytochrome P-450c relative to P-450d was lower after the more prolonged AAF feeding. Supplementation of AAF-containing diets with 0.3% butylated hydroxytoluene (BHT), which affords protection against AAF hepatocarcinogenesis in high-fat fed rats, protected and/or induced total (spectral) nuclear envelope cytochrome P-450 content. Immunochemical studies of liver fractions showed that BHT enhanced the AAF-dependent induction of cytochrome P-450c, but not of P-450d. This was a concerted effect of AAF + BHT since dietary BHT by itself did not affect the levels of cytochrome P-450c or P-450d as compared to control rats. Since 1- to 3-week dietary AAF had little effect on total (spectral analyses) microsomal cytochrome P-450 but markedly reduced total P-450 in nuclear envelopes, the coordinated induction of specific cytochrome P-450s in the different fractions suggests selective induction and depression of different forms of cytochrome P-450 and provides additional evidence for independent regulation of the drug-metabolizing system in nuclear envelope and microsomes. In addition, these results suggest that regulation of cytochrome P-450 may play a crucial role in the nutritional modulation of AAF hepatocarcinogenesis.

2-Acetylaminofluorene↗
PubMed1989

Subject-reported compliance in a chemoprevention trial for familial adenomatous polyposis.

A high level of compliance with an assigned treatment regimen is fundamental to accurate assessment of treatment effectiveness in any clinical trial. If compliance is poor, an effective treatment may be confounded by inadequate delivery of the regimen. Although much research has focused on broad aspects of compliance dealing with clinical therapeutic situations, there was a need for further research dealing specifically with adherence issues in a long-term chemoprevention trial since subject motivation in the latter is likely to differ from that of the former. Examining subject-reported compliance over the first 2-year treatment periods of a long-term chemoprevention trial for familial adenomatous polyposis, it was found that (1) compliance decreased over time, (2) fiber compliance was lower than vitamin compliance, and (3) four explanatory variables which may be amenable to individualized study-team interventions emerged as useful prognosticators of fiber compliance.

Activities of Daily Living↗