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Biomedical subjects

C D Miller

Publications and source records attributed to C D Miller.

At least 37 records · Page 2Linked to original sources
PubMed2000

Superoxide dismutase activity in Pseudomonas putida affects utilization of sugars and growth on root surfaces.

To investigate the role of superoxide dismutases (SOD) in root colonization and oxidative stress, mutants of Pseudomonas putida lacking manganese-superoxide dismutase (MnSOD) (sodA), iron-superoxide dismutase (FeSOD) (sodB), or both were generated. The sodA sodB mutant did not grow on components washed from bean root surfaces or glucose in minimal medium. The sodB and sodA sodB mutants were more sensitive than wild type to oxidative stress generated within the cell by paraquat treatment. In single inoculation of SOD mutants on bean, only the sodA sodB double mutant was impaired in growth on root surfaces. In mixed inoculations with wild type, populations of the sodA mutant were equal to those of the wild type, but levels of the sodB mutant and, to a great extent, the sodA sodB mutant, were reduced. Confocal microscopy of young bean roots inoculated with green fluorescent protein-tagged cells showed that wild type and SOD single mutants colonized well predominantly at the root tip but that the sodA sodB double mutant grew poorly at the tip. Our results indicate that FeSOD in P. putida is more important than MnSOD in aerobic metabolism and oxidative stress. Inhibition of key metabolic enzymes by increased levels of superoxide anion may cause the impaired growth of SOD mutants in vitro and in planta.

Blotting, Southern↗
PubMed2000

Meeting American Diabetes Association guidelines in endocrinologist practice.

OBJECTIVE: To determine whether American Diabetes Association (ADA) guidelines can be met in the context of routine endocrinology practice. RESEARCH DESIGN AND METHODS: Charts were reviewed for a group of patients who were examined in 1998, followed for > or = 1 year, and had two or more visits during that year. Process measures and metabolic outcomes were studied for patients with type 2 diabetes, and glycemic control was assessed for patients with type 1 diabetes. RESULTS: A total of 121 patients with type 2 diabetes had a mean age of 63 years, a mean BMI of 31 kg/m2, and a mean duration of diabetes of 12 years. Many had comorbidities or complications: 80% had hypertension, 64% had hyperlipidemia, 78% had neuropathy, 22% had retinopathy, and 21% had albuminuria. Management of type 2 diabetic patients was complex: 38% used oral hypoglycemic agents alone (54% of these were using two or more agents), 31% used oral hypoglycemic agents and insulin, and 26% used insulin alone; 42% of patients taking insulin therapy injected insulin three or more times per day. Within 12 months, 74% of patients had dilated eye examinations, 70% had lipid profiles, and 55% had urine albumin screening. Of the patients, 87% had a foot examination at their last visit. Blood pressure levels averaged 133/72 mmHg, cholesterol levels averaged 4.63 mmol/l, triglyceride levels averaged 1.99 mmol/l, HDL cholesterol levels averaged 1.24 mmol/l, and LDL cholesterol levels averaged 2.61 mmol/l. Random blood glucose levels averaged 8.0 mmol/l, and HbAlc levels averaged 6.9 +/- 0.1%. A total of 87% of patients had HbAlc levels < or = 8.0%. A total of 30 patients with type 1 diabetes had mean age of 44 years, a mean BMI of 26 kg/m2, and a mean duration of diabetes of 20 years. All type 1 diabetic patients used insulin and averaged 3.4 injections a day; their average HbAlc level was 7.1 +/- 0.2%, and 80% had HbAlc levels < or = 8.0%. CONCLUSIONS: Although endocrinologists must manage patients with multifaceted problems, complex treatment regimens yield glycemic control levels comparable with the Diabetes Control and Complications Trial and allow ADA guidelines to be met in a routine practice setting.

Analysis of Variance↗
PubMed1999

Transcriptional regulation by iron of genes encoding iron- and manganese-superoxide dismutases from Pseudomonas putida.

Genes from Pseudomonas putida (Pp), sodA, encoding manganese-superoxide dismutase (MnSOD) and, sodB, iron-superoxide dismutase (FeSOD) were cloned by hybridization with digoxigenin (dig)-labeled PCR products generated from Pp genomic DNA. The sodB gene had a 594 bp open reading frame (ORF), corresponding to 198 amino acids (aa), and a transcript of 880 bases. The sodA gene contained a 609 bp ORF encoding 203 aa and was transcribed as part of a polycistronic operon, consisting of orfY-fumC-orfX-sodA. Pp sodA or sodB genes both restored aerobic growth, growth on paraquat, and growth on minimal medium to an Escherichia coli (Ec) mutant deficient in SOD activity. Paraquat treatment did not enhance mRNA transcription of the sod genes or increase SOD activity in Pp. The Pp sodB gene was highly expressed throughout logarithmic-(log) growth phase and stationary-phase cells grown in medium supplemented with FeCl3, but was down-regulated in iron-deficient conditions, such as in stationary-phase or generated by 2,2'-dipyridyl (DP) treatment. This is the first evidence that iron regulates expression of the sodB gene at the transcriptional level. In contrast, iron-deficient conditions, or addition of MnCl2 to the growth medium, induced transcripts (2.4 kb and 1.2 kb) from the sodA operon. Our results reveal an intricate role of iron in the transcriptional regulation of both Pp sodA and sodB genes.

Cell Division↗
PubMed1997

Identification of adjacent genes encoding the major catalase and a bacterioferritin from the plant-beneficial bacterium Pseudomonas putida.

The catA gene, encoding the major CatA from a root-colonizing isolate Pseudomonas putida (Pp), was cloned by complementation into a catalase (Cat)-deficient Escherichia coli (Ec) strain UM2. The ORF for catA consisted of 479 aa with a higher degree of identity with typical Cat from eukaryotes than prokaryotes. Chromosomal homologous exchange with a mutant gene bearing an insertion of a luxAB-npt cassette into the SfiI site of catA generated a CatA-deficient Pp isolate. This mutant and another mutant, J1M, derived by EMS mutagenesis, were highly sensitive to hydrogen peroxide. CatA activity and resistance to hydrogen peroxide were restored in both mutants by catA. Adjacent to the 3' end of catA was a potential ORF of 462 nt that had high identitity with other bfr genes that encode iron-storage proteins. Northern analysis of the bfr gene from Pp revealed a transcript of approximately 500 nt. CatA and bfr probes hybridized to the same size restriction fragments in genomic DNAs from other root-colonizing and plant pathogenic pseudomonads. Thus, the genes for an iron-storage protein and the heme-containing Cat appear to be conserved in adjacent loci in certain pseudomonads.

Amino Acid Sequence↗
PubMed1997

Arthroscopic reconstruction of traumatic anterior instability of the shoulder: the Caspari technique.

In a prospective study, all patients with recurrent traumatic anterior instability of the shoulder were treated by an arthroscopic transglenoid suture reconstruction; 163 consecutive patients were treated during the 3-year period of the study. The average number of dislocations per patient was 11, average age 27 years, and the average preoperative Bankart score 15. All patients underwent reconstruction using the Caspari technique of arthroscopic suture reconstruction. Of the 163 patients, 161 were re-evaluated 36 to 72 months postoperatively. Overall, 147 (91%) of the patients rated as satisfactory and 14 (9%) rated as unsatisfactory. The average postoperative Bankart score for all patients was 89. Twenty of 27 patients (76%) younger than age 18 achieved a satisfactory result. Forty-nine of 54 college-age patients achieved a satisfactory result. In patients older than 22 years, 97.5% (78 of 80) achieved a satisfactory result. In this extensive study, it would appear that the success of this arthroscopic technique is age-related, with younger patients having a less successful result than older patients. Arthroscopic reconstruction with this technique provides results equal to those of the open procedure for patients age 22 years and older and would provide a success rate of 90% in patients age 18 to 22. However, it is effective only 74% of the time in patients younger than 18 and is not indicated for patients in this age range.

Adolescent↗
PubMed1997

Cloning and mutational analysis of the gene for the stationary-phase inducible catalase (catC) from Pseudomonas putida.

Pseudomonas putida, a bacterium that colonizes plant roots and enhances plant growth, produces three isozymes of catalase (A, B, and C) in stationary-phase cells. A catalase probe, generated by PCR analysis of P. putida genomic DNA with oligomers based on typical catalase sequences, hybridized to a genomic clone that expressed catalase C in Escherichia coli. The catC gene from this clone had a 2,133-bp open reading frame with a high level of identity to the stationary-phase-specific E. coli katE. Chromosomal mutants of P. putida deficient in catalase C, obtained by gene interruption with a luxAB-npt cassette, demonstrated enhanced catC transcription in stationary-phase cells and, upon exposure to phenol, in logarithmic-phase cells. The catalase C-deficient cells were not impaired in their ability to colonize roots of bean or wheat plants grown under sterile conditions.

Amino Acid Sequence↗
PubMed1996

Effect of corrective rearfoot orthotic devices on ground reaction forces during ambulation.

OBJECTIVE: To determine the quantitative effects of a corrective rearfoot orthotic device on the vertical, anteroposterior, and mediolateral ground reaction forces (GRFs) during ambulation. DESIGN: We conducted a prospective, randomized, single-blinded study of 25 subjects during ambulation with and without a rearfoot orthotic device. MATERIAL AND METHODS: Thirteen men and 12 women were enrolled in the study; the inclusion criteria included asymptomatic pes planus (5 to 10 degrees of calcaneal eversion). Each subject walked across a standard force plate in 10 trials without an orthotic device. The force plate was used to quantify the effect of a semirigid functional rearfoot orthotic device on GRFs and the center of pressure versus a standard shoe with no device. The observer was blinded, trials were completed in random order, and the paired t test was used for statistical analysis. RESULTS: No evidence suggested the presence of a significant difference in mediolateral GRFs and in the center of pressure exerted at 10%, 20%, 50%, and 80% of stance phase with and without the orthotic device. Significant reductions were noted in vertical GRFs per newton of body weight exerted at 10% (P = 0.0009) and 20% (P = 0.0383) of stance phase and in anteroposterior GRFs exerted at 10% (P = 0.0009) and 50% (P = 0.0033) of stance phase when ambulation was compared with and without the orthotic device. CONCLUSION: These results indicate that a rearfoot orthotic device reduces vertical and anteroposterior GRFs in the early stages of the stance phase during the gait cycle. We found no evidence to suggest a significant difference at any of the percent stance phases when comparisons were made of mediolateral GRFs exerted with and without the orthotic device. These data are contrary to current hypotheses about use of orthotic devices, and further studies would be helpful to reproduce these findings and to determine whether these changes are related to clinical improvement in symptomatic pes planus.

Adolescent↗
PubMed1996

Transcriptional repression of the ovine follicle-stimulating hormone-beta gene by 17 beta-estradiol.

Direct transcriptional inhibition of the gene that encodes ovine FSH beta-subunit (oFSH beta) by 17 beta-estradiol (E2) has been previously demonstrated by our laboratory. To determine which cis-acting elements in the 5'-flanking region of this gene may be involved in E2 regulation, DNA constructs containing deletions of the 5'-end of the oFSH beta gene were fused to a luciferase reporter and tested in transient transfection assays. These oFSH beta-luciferase constructs and the human E2 receptor expression vector (HEO) were transfected into primary cultures of ovine pituitary cells and subsequently tested with E2. Expression of the largest oFSH beta-luciferase construct (-4741 to +759 of oFSH beta) was inhibited 50% by 20 nM E2. Repression was dependent upon cotransfection of estrogen receptor (HEO) and was E2 dose dependent, with an apparent ED50 similar to that of the positive control consensus estrogen-responsive element construct, ERETk-LUC (ED50 = 50 pM). Deletion studies indicated that sequences between- 105 and -84 bp are necessary for this repression. In addition, a synthetic nucleotide containing oFSH beta sequences from - 105 to -72 could direct E2-dependent repression of a heterologous thymidine kinase promoter that drives luciferase expression. Additional experiments showed that no tissue-specific elements were required for either basal expression or E2-directed transcriptional repression. Although there are no consensus DNA response elements for the estrogen receptor between -105 and +759 of the oFSH beta gene, cotransfection of a mutant E2 receptor lacking the DNA-binding domain (HE-11) failed to mediate E2-dependent inhibition. Gel retardation studies, using the oligonucleotide-containing oFSH beta sequences from -105 to -72, indicated no evidence of direct binding of the estrogen receptor to DNA from -105 to -72. The studies presented here indicate that transcriptional repression of the oFSH beta gene by E2 may be directed in vivo by 5'-flanking sequences between -105 and -72 of the oFSH beta gene. Furthermore, the data suggest that inhibition is mediated via E2 receptor-protein interactions with basal transcription factors that may bind to the -105/-72 DNA directly.

Animals↗
PubMed1993

Procainamide-induced myasthenia-like weakness and dysphagia.

A 64-year-old man with chronic renal insufficiency was hospitalized with dysphagia and inability to keep his head erect 11 months after beginning procainamide hydrochloride (PA) for control of atrial flutter. Evaluation revealed esophageal dysmotility, worsening renal function, and elevated serum PA and N-acetylprocainamide (NAPA) concentrations. No evidence of autoimmune myasthenia gravis was found. PA was discontinued and normalization of PA and NAPA concentrations was associated with a decrease in muscle weakness and resolution of dysphagia. The correlation between clinical findings and serum concentrations of PA and NAPA suggests that drug excess due to impaired clearance was the basis for this unusual adverse drug reaction.

Acecainide↗
PubMed1993

Evaluation of agar gel immunodiffusion and indirect fluorescent antibody assays as supplemental tests for dourine in equids.

The agar gel immunodiffusion (AGID) and indirect fluorescent antibody (IFA) assays were evaluated as supplemental tests to the complement-fixation (CF) test, the official US importation certification test for dourine in equids. The American stabilate (n = 10 animals) or the Canadian stabilate (n = 6 animals) of Trypanosoma equiperdum cultured in rat blood was administered by catheterization and infusion in the urogenital tract of 16 equids. To assess parasitemia and serologic responses by use of the CF, AGID, and IFA tests, a total of 787 serum and blood samples were obtained from equids before exposure and 3 times a week after exposure to T equiperdum. Results of the IFA and AGID tests were compared with the CF test results. The disease was diagnosed earlier by the IFA test than by the AGID test, regardless of antigen preparation or exposure group. The mean number of days between exposure and positive result by the CF and IFA tests was the same when either homologous or heterologous antigen was used in the IFA test. In general, the IFA test was more sensitive than the AGID test in diagnosing dourine, regardless of the antigen preparation used in the test or exposure group. Differences in test specificity were observed among both groups of exposed equids when either antigen was used (P < 0.05). The AGID test, using the American antigen, was more specific than the IFA test for sera from both groups of equids. When the Canadian antigen was used, the IFA test was a more specific test than the AGID test (P < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Agar↗
PubMed1991

The gene encoding ovine follicle-stimulating hormone beta: isolation, characterization, and comparison to a related ovine genomic sequence.

Follicle-stimulating hormone (FSH), the primary stimulus for egg and sperm maturation in mammals, is an alpha/beta heterodimer. Each subunit is encoded by a single-copy gene in the human, bovine, and rat genomes. Transcription of both subunits is inhibited by estradiol and progesterone in ovine pituitary cultures. We report the sequence of one ovine FSH-beta gene (-1,527 to +3,664) that is expressed in vivo and the identification of a novel, second ovine FSH-beta-like sequence. Digestion of ovine genomic DNA with Bgl II yielded two fragments of 10 kb and 15 kb that hybridized to a bovine FSH-beta cDNA. The 10-kb fragment contained 6 kb of 5'-flanking region and all but about 200 bp of the 3' terminus of the ovine FSH-beta gene. This FSH-beta gene encodes a protein that differs from the published ovine protein sequence only at the carboxy terminus (Arg-109Glu-110[STOP codon] instead of Glu-109Arg-110[Glx-111]) and at positions 49 (Ala instead of Thr) and 88 (Arg instead of Ser). This gene is organized similarly to the human, bovine, porcine, and rat FSH-beta genes, and its coding sequence is nearly identical (99.5%) to a reported ovine FSH-beta cDNA. Expression of the FSH-beta gene on the 10-kb fragment in vivo was determined by analysis of wether mRNA using the polymerase chain reaction. A 95-bp sequence of the 15-kb fragment was 87% homologous to the corresponding coding region of the 10-kb fragment. This comparison suggested that the 15-kb fragment contains either an FSH-beta-like sequence or a pseudogene. Several potential steroid response elements were found by sequence analysis of the 5'-flanking region of the FSH-beta gene on the 10-kb fragment. A mechanism by which these elements may act is suggested.

Amino Acid Sequence↗
PubMed1991

A monoclonal antibody defines a geographically conserved surface protein epitope of Babesia equi merozoites.

Babesiosis is a tick-borne hemoparasitic disease affecting horses worldwide. To investigate mechanisms of immunity to this parasite, the antibody response of infected horses to Babesia equi merozoite proteins was evaluated. Immunoprecipitation of B. equi merozoite antigens with sera from infected horses revealed 11 major proteins of 210, 144, 108, 88, 70, 56, 44, 36, 34, 28, and 25 kDa. Monoclonal antibody (MAb) 36/133.97, which binds to live merozoites, immunoprecipitated proteins of 44, 36, 34, and 28 kDa. When immunoprecipitations were performed with in vitro translation products of merozoite mRNA, MAb 36/133.97 immunoprecipitated proteins of 38, 28, 26, and 23 kDa which comigrated with proteins immunoprecipitated by sera from infected horses at 10(-3) to 10(-4) dilutions. In Western blot analysis, MAb 36/133.97 recognized proteins of 44, 36, 34, and 28 kDa, and a 28-kDa protein was identified by sera from infected horses at a dilution of 10(-4). MAb 36/133.97 bound to B. equi isolates from Florida and Europe. Furthermore, the binding of MAb 36/133.97 to merozoite proteins was inhibited by sera of infected horses from 19 countries. Collectively, these data indicate MAb 36/133.97 binds to a geographically conserved peptide epitope on multiple B. equi merozoite proteins, including a merozoite surface protein, and MAb 36/133.97 reacts with a B. equi protein immunodominant in infected horses.

Animals↗
PubMed1990

Ultraviolet light-induced DNA damage in transcribed sequences: no change in repair with age.

We studied the repair of a plasmid vector containing the chloramphenicol acetyltransferase (CAT) gene by treating the plasmid with UV light and then transfecting this plasmid into fibroblasts from human fetal lung (in vitro aging) and into primary cultured fibroblasts from rat lung and skin. This methodology allows us to examine the repair of specific transcribed DNA sequences. There was no age-related change in the repair of UV damage in these cells. Rat embryo fibroblasts at different passages transfected with the plasmid also revealed no significant alteration in UV repair as a function of passage number.

Aging↗
PubMed1990

DNA alterations in prostatic adenocarcinoma and benign prostatic hyperplasia: detection by DNA fingerprint analyses.

DNA fingerprinting can be utilized to examine a large number of autosomal loci throughout the human genome. Alterations in banding patterns observed on DNA fingerprint analyses reflect DNA alterations ranging from single base changes to complex chromosomal rearrangements. In this report, we describe the application of this technique to prostatic adenocarcinoma (CAP) and benign prostatic hyperplasia (BPH). The majority of CAP cases (12 of 14) displayed alterations in at least 1 of the approximately 30 resolvable bands obtained by fingerprint analyses when compared with DNA obtained from peripheral white blood cells. Unexpectedly, 5 of the 12 cases of BPH examined revealed at least 1 identifiable band alteration in the prostatic tissue. These findings demonstrate the usefulness of fingerprint analyses in the examination of cancer-associated genetic alterations. They also suggest the presence of observable genetic alterations in BPH.

Adenocarcinoma↗