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Biomedical subjects

R L Cox

Publications and source records attributed to R L Cox.

At least 19 recordsLinked to original sources
PubMed2001

Characterization of Rhodobacter sphaeroides cytochrome c(2) proteins with altered heme attachment sites.

In c-type cytochromes, heme is attached to the polypeptide via thioether linkages between vinyl groups on the tetrapyrrole ring and cysteine thiols in a CX(2)CH motif. To study the role of the heme-binding site in c-type cytochrome assembly and function, we generated amino acid changes in this region of Rhodobacter sphaeroides cytochrome c(2) ((15)Cys-Gln-Thr-Cys-His(19)). Amino acid substitutions at Cys(15), Cys(18), or His(19) produced mutant proteins that did not support growth via photosynthesis where this electron carrier is required. Many of these changes appeared to slow signal peptide removal, suggesting that heme attachment is coupled to processing of the c-type cytochrome precursor protein. Inserting an alanine between the cysteine ligands (CycA-Ins17A) did not significantly alter the behavior of this protein in vivo and in vitro, suggesting that the existence of 2 residues between cysteine thiols is not essential for heme attachment to a Class I c-type cytochrome like cytochrome c(2).

Amino Acid Sequence↗
PubMed2001

Nitric oxide synthase sequences in the marine fish Stenotomus chrysops and the sea urchin Arbacia punctulata, and phylogenetic analysis of nitric oxide synthase calmodulin-binding domains.

The phylogenetic distribution and structural diversity of the nitric oxide synthases (NOS) remain important and issues that are little understood. We present sequence information, as well as phylogenetic analysis, for three NOS cDNAs identified in two non-mammalian species: the vertebrate marine teleost fish Stenotomus chrysops (scup) and the invertebrate echinoderm Arbacia punctulata (sea urchin). Partial gene sequences containing the well-conserved calmodulin (CaM)-binding domain were amplified by RT-PCR. Identical 375-bp cDNAs were amplified from scup brain, heart, liver and spleen; this sequence shares 82% nucleic acid and 91% predicted amino acid identity with the corresponding region of human neuronal NOS. A 387-bp cDNA was amplified from sea urchin ovary and testes; this sequence shares 72% nucleic acid identity and 65% deduced amino acid identity with human neuronal NOS. A second cDNA of 381 bp was amplified from sea urchin ovary and it shares 66% nucleic acid and 57% deduced amino acid identity with the first sea urchin sequence. Together with earlier reports of neuronal and inducible NOS sequences in fish, these data indicate that multiple NOS isoforms exist in non-mammalian species. Phylogenetic analysis of these sequences confirms the conserved nature of NOS, particularly of the calmodulin-binding domains.

Amino Acid Sequence↗
PubMed2001

Roles for the Rhodobacter sphaeroides CcmA and CcmG proteins.

Rhodobacter sphaeroides cells containing an in-frame deletion within ccmA lack detectable soluble and membrane-bound c-type cytochromes and are unable to grow under conditions where these proteins are required. Only strains merodiploid for ccmABCDG were found after attempting to generate cells containing either a ccmG null mutation or a ccmA allele that should be polar on to expression of ccmBCDG, suggesting that CcmG has another important role in R. sphaeroides.

Bacterial Outer Membrane Proteins↗
PubMed1998

Initial evidence for reliability and validity of a brief screening inventory for personality traits.

A short inventory was developed to screen for avoidant, borderline, and dependent personality disorders in clinic settings. The Personality Concerns Inventory items, adapted from the DSM-IV criteria for these disorders, along with the Millon-III was administered to 86 undergraduate students. Reliability estimates for the three scales were .87, .81, and .80. Scores on the three scales also correlated .49 to .57 with scores on the Avoidant, Borderline, and Dependent scales of the Millon-III.

Adolescent↗
PubMed1995

Complications of cryosurgical ablation of the prostate to treat localized adenocarcinoma of the prostate.

OBJECTIVES: To review the complications associated with cryosurgical ablation of the prostate (CSAP) for localized adenocarcinoma of the prostate in the first 69 procedures performed at our institution. METHODS: A retrospective review of the charts of 63 patients (69 procedures) performed at our institution between June, 1993, and December, 1994, was undertaken with an emphasis on the complications, their management, and outcome. RESULTS: Thirty-seven of the 63 patients (59%) had at least one significant adverse event. Although no patient died or required a transfusion, other significant complications, including prolonged urinary retention, incontinence, sloughing of prostatic tissue, fistula formation, prolonged perineal pain, bowel dysfunction, and other problems were observed. CONCLUSIONS: CSAP is associated with a significant complication rate. These complications are more common in patients who have had prior CSAP or radiation therapy. Instead of decreasing with experience, the complication rate increased later in the series. In our patients, the complication rate increased after the use of an investigational urethral warmer was discontinued. CSAP is an investigational procedure of unproved long-term efficacy. It can be associated with substantial patient morbidity and should be performed under carefully controlled circumstances. Patients should be made aware of the potential for debilitating complications.

Adenocarcinoma↗
PubMed1995

Estrogens in the treatment of prostate cancer.

PURPOSE: The history, mechanisms of action, efficacy and complications of estrogen therapy for prostate cancer are reviewed, and the current and future roles of estrogens in the treatment of prostate cancer are addressed. MATERIALS AND METHODS: An extensive review of the literature was done. RESULTS: Estrogens are effective in the treatment of advanced prostate cancer. High dose oral estrogens are associated with an increased risk of cardiovascular death. A dose of 1 mg. diethylstilbestrol daily is not associated with an increased risk of cardiovascular death. Estrogens are associated with other toxicities. Parenteral estrogens may not have the risk of cardiovascular death that is ascribed to oral estrogens. Estrogens have not been adequately compared to the combined androgen blockade regimen. CONCLUSIONS: A 1 mg. dose of diethylstilbestrol remains a medial alternative to bilateral orchiectomy in the treatment of advanced prostate cancer. Doses of 3 mg. diethylstilbestrol or more have a prohibitively high risk of cardiovascular death. Further studies comparing the efficacy, complications and cost of regimens containing oral estrogens or parenteral estrogens with agents that increase efficacy (for example antiandrogens) and decrease toxicity (for example anticoagulants) to results of other regimens, such as combined androgen blockade, should be done to determine if an estrogen-containing regimen could lower the cost of treating advanced prostate cancer.

Estrogens↗
PubMed1995

Amnioinfusion for preventing puerperal infection. A prospective study.

OBJECTIVE: To evaluate the hypothesis that irrigation of the uterine cavity by amnioinfusion in women with membranes ruptured for greater than six hours would decrease maternal puerperal infection. STUDY DESIGN: We designed a prospective study at three teaching institutions. Sixty-eight women were randomized to receive either amnioinfusion or routine care. Amnioinfusion was through preexisting internal uterine pressure catheters with a 300-500-mL bolus and a 125-150 mL/h constant drip. Chorioamnionitis and endometritis were evaluated as the outcome variables. RESULTS: Women from the amnioinfusion group, n = 36, and the control group, n = 32, had similar times in labor (mean 4 hours), times of ruptured membranes (mean 18 hours), vaginal examinations (mean 7), gestational age (mean 40 weeks), types of anesthesia and methods of delivery. Women who received amnioinfusion had significantly less puerperal infection, 9/36, as compared to women in the control group, 16/32 (P < .033, relative risk = .5, confidence interval .26-.94). There were no cases of neonatal sepsis in either group, and there were no complications from the amnioinfusions. CONCLUSION: In this study of women at high risk for puerperal infection, amnioinfusion was an inexpensive and safe technique for reducing the incidence of infection.

Adolescent↗
PubMed1994

Coordinate induction of I kappa B alpha and NF kappa B genes.

The NF kappa B transcription factor exists in an inactive state when complexed with I kappa B alpha in the cytosol. Upon stimulation by a variety of agents, NF kappa B is released from I kappa B alpha and is translocated to the nucleus to induce kappa B motif-containing promoters. Once I kappa B alpha is dissociated from NF kappa B, I kappa B alpha is rapidly degraded. Few studies have been reported concerning the molecular basis for the regulation of I kappa B alpha gene expression. The current studies now show: (1) the expression of I kappa B alpha can be induced by protein synthesis inhibitors including cycloheximide, anisomycin, and puromycin; (2) cycloheximide-dependent induction can be blocked by a transcriptional inhibitor; (3) double-stranded RNA and tumor necrosis factor alpha, which are both known to induce NF kappa B, induce the expression of I kappa B alpha, whereas L-cysteine, which is known to inhibit NF kappa B expression, inhibits I kappa B alpha expression; and (4) the induction of I kappa B alpha gene expression is transient, as is the induction of other NF kappa B-inducible genes. These findings suggest that I kappa B alpha is a NF kappa B-inducible gene. The current results also show a concomitant induction of both subunits of NF kappa B (p50 and p65) after the treatment of cells with double-stranded RNA. Based on these results, a model is proposed suggesting the existence of integrated pathways for the positive and negative autoregulation of I kappa B alpha and NF kappa B.

Amino Acid Sequence↗
PubMed1992

Encephalopathy and seizures induced by intravesical alum irrigations.

Hemorrhagic cystitis is a significant toxic effect of cyclophosphamide therapy. Continuous bladder irrigation of a 1% alum solution is a simple and generally safe method of chemical cautery to treat the bleeding urothelium. We report four cases of encephalopathy coincident with elevated aluminum levels as well as one patient who developed seizures while receiving continuous bladder irrigations with alum. All patients had significant renal insufficiency. We recommend the cautious use of alum irrigation in patients with renal impairment and monitoring of serum aluminum levels to prevent excessive accumulation and toxicity.

Administration, Intravesical↗
PubMed1987

Operative therapy for cholecystitis and cholelithiasis: trends over three decades.

Gallstones constitute a major health problem. In the United States there are approximately 800,000 new cases of cholelithiasis each year. Several developments within the last 20 years are likely to have altered the profile of patients requiring cholecystectomy. All patients undergoing cholecystectomy at three hospitals during 1 year of the last 3 decades were reviewed. The results demonstrate a relative increase in the proportion of elderly patients undergoing cholecystectomy. The incidence of gallstones in blacks appears to be rising. Cholangiography significantly decreased the number of negative common duct explorations throughout this 20-year period. The percentage of patients with choledocholithiasis was stable from 1964 to 1984.

Adult↗
PubMed1983

Controlled evaluation of hypertonic sucrose medium at a 1:5 ratio of blood to broth for detection of bacteremia and fungemia in supplemented peptone broth.

The value of hypertonic media in the detection of bacteremia and fungemia is controversial, since prior clinical trials have yielded conflicting results with different media. Earlier, we showed that the addition of 10% sucrose to supplemented peptone broth at a 1:10 ratio of blood to broth yielded better recovery of Staphylococcus epidermidis, the Enterobacteriaceae, Pseudomonas aeruginosa, and yeasts. To evaluate the effect of 10% sucrose on blood cultured at a 1:5 ratio, we compared the yield and speed of detection of clinically important microorganisms from adult patients in 5,839 blood samples cultured in supplemented peptone broth with 0.03% sodium polyanetholesulfonate with and without 10% sucrose. The atmosphere of incubation (open venting units), 1:5 ratio of blood to broth, and methods of processing were the same for both bottles. Recovery of facultative gram-positive (P less than 0.02) and gram-negative (P less than 0.02) bacteria was improved, but the recovery of anaerobic gram-negative bacteria was both reduced (P less than 0.01) and delayed (P less than 0.02) by sucrose. The total yield of microorganisms including fungi, however, was increased with sucrose. The effect of sucrose on blood cultures appears to depend on the ratio of blood to broth as well as on the medium used and strains of microorganisms encountered.

Bacteria↗
PubMed1982

Comparative evaluation of supplemented peptone broth with sodium polyanetholesulfonate and trypticase soy broth with sodium amylosulfate for detection of septicemia.

We compared the yield and speed of detection of clinically important microorganisms from 10,156 paired 5-ml samples of blood cultured in supplemented peptone broth (SPB) with 0.03% sodium polyanetholesulfonate (SPS) or Trypticase soy broth (TSB) with 0.5% sodium amylosulfate (SAS). The atmosphere of incubation (open venting units) and ratio of blood to broth (1:10) were the same for both samples. Only cultures with adequate blood samples (greater than or equal to 80% of stated volume) were compared statistically. Overall, SPB/SPS outperformed TSB/SAS. Bacteroidaceae and Eubacterium were found more often (P less than 0.05) and viridans streptococci were found sooner (P less than 10(-4)) in SPB/SPS than in TSB/SAS. Most importantly, staphylococci were found both more often (P less than 0.03) and sooner (P less than 10(-7)) in SPB/SPS than in TSB/SAS. In a separate experiment, SAS slowed the growth of a clinical strain of Staphylococcus aureus in TSB. Unless important advantages can be confirmed for SAS in controlled clinical trials, SAS cannot be recommended for routine use as an anticoagulant in blood culture media.

Amylopectin↗
PubMed1979

False-positive Gram-stained smears.

The rate per 1,000 smears showing nonviable Gram-negative bacilli (false-positive smears) increased from a baseline of 10.8 to 38.5 following purchase of new culture-collection devices; the rate decreased to 8.0 following replacement of contaminated culture sets. False-positive reports led to changes in therapy for five patients. In addition to being sterile, commercial culture-collection devices should be certified by the manufacturer as being free of stainable microorganisms or as unsuitable for preparation of Gram-stained smears.

Adolescent↗
PubMed1979

Auricular sporotrichosis in a brick mason.

A case of cutaneous sporotrichosis involving the auricle of a brick mason is reported. Despite the infrequency of such an infection, sporotrichosis must be considered in the differential diagnosis of perichondritis. The occupational associations with Sporothrix schenckii are reviewed and the relationship with bricks is emphasized.

Adult↗