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E Davidson

Publications and source records attributed to E Davidson.

At least 91 records · Page 5Linked to original sources
PubMed1987

Primary structure of the bc1 complex of Rhodopseudomonas capsulata. Nucleotide sequence of the pet operon encoding the Rieske cytochrome b, and cytochrome c1 apoproteins.

The nucleotide sequence of the pet operon of Rhodopseudomonas capsulata strain SB1003 has been determined. This operon consists of the petA, petB and petC genes, which encode the Rieske Fe-S protein, cytochrome b and cytochrome c1, respectively, all components of the ubiquinol-cytochrome c2 oxidoreductase. The deduced amino acid sequences of the pet genes show homology to the corresponding proteins from other organisms, and particularly high homologies (over 90% for amino acid and nucleotide sequences) to the previously described fbc operon from a strain previously identified as Rhodopseudomonas spheroides GA. The amino acid sequences of the pet proteins are discussed with reference to the structure and function of the ubiquinol-cytochrome c2 oxidoreductase.

Amino Acid Sequence↗
PubMed1987

fbc operon, encoding the Rieske Fe-S protein cytochrome b, and cytochrome c1 apoproteins previously described from Rhodopseudomonas sphaeroides, is from Rhodopseudomonas capsulata.

Detailed comparison of the 'Rhodopseudomonas sphaeroides GA' strain used by Gabellini et al. (1985) with genuine R. sphaeroides and R. capsulata strains indicated that the previously reported fbc operon of R. sphaeroides (Gabellini and Sebald, 1986) encoding the structural genes for the Rieske Fe-S protein, cytochrome b and cytochrome c1 subunits of the ubiquinol:cytochrome c2 oxidoreductase, is not from R. sphaeroides, but is rather from a strain of R. capsulata. Consequently, the genuine bc1 genes from R. sphaeroides were cloned using corresponding R. capsulata genes as probes, and a partial nucleotide sequence for the Rieske Fe-S protein of R. sphaeroides was determined and compared with that of R. capsulata.

Amino Acid Sequence↗
PubMed1987

Short- and long-term dobutamine treatment in chronic ischemic heart failure.

This study was undertaken in order to characterize the short-term (1 hour) and long-term (72 hours) effect of dobutamine on hemodynamic and regional ejection fraction parameters measured by radionuclear angiography in patients with chronic congestive heart failure due to coronary artery disease. Baseline hemodynamic and radionuclear parameters were measured and then intravenous dobutamine (8.5 mu/kg/min) was administered. The above parameters were determined again after 1 hour and 72 hours of continuous dobutamine administration. Sixty minutes (short-term) after dobutamine administration heart rate and cardiac index increased significantly (p less than 0.001 for both) and peripheral resistance decreased concomitantly (p less than 0.005). Global left ventricular ejection fraction (LVEF) as measured by multigated equilibrium nuclear angiography (MUGA) increased from 21.8 +/- 10.6% to 25 +/- 13.5 (p less than 0.02). Count-based mean regional ejection fraction in the septal, inferoapical, posterolateral (45 degrees left anterior oblique view) and inferior apical and anterolateral (30 degree right anterior oblique gated first pass) regions increased also. At 72 hours (long-term) after continuous dobutamine infusion, heart rate and cardiac index were still significantly higher and peripheral resistance lower than in the control study. However, global and count-based regional ejection fraction decreased to control values in the right anterior oblique view (first-pass analysis) and the left anterior oblique view (MUGA). Global LVEF measured in the right anterior oblique view by first-pass technique was significantly higher than control in the long-term study (23 +/- 9.7 vs. 27.8 +/- 2.4; p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1987

A lineage-specific gene encoding a major matrix protein of the sea urchin embryo spicule. I. Authentication of the cloned gene and its developmental expression.

The developing sea urchin embryo forms endoskeletal CaCO3 containing spicules which are elaborated by the primary mesenchyme cells, descendants of the micromeres, beginning at gastrulation. In this and the accompanying paper [H. M. Sucov, S. Benson, J. J. Robinson, R. J. Britten, F. Wilt, and E. H. Davidson (1987) Dev. Biol. 120, 507-519] the isolation and characterization of a gene that encodes a 50-kDa spicule matrix glycoprotein that we call SM50 are described. A cloned cDNA isolated from a lambda gt11 library was used in hybrid-selected translation and hybrid arrest of translation experiments to verify that the cDNA encodes a spicule matrix protein. The cognate RNA transcript encodes a 50-kDa protein which is precipitated by polyclonal antisera against spicule matrix proteins and is present only in polyadenylated RNA at stages known to be making a spicule. The cloned cDNA sequence described in the accompanying paper was used to follow the time of expression of the cognate gene by RNA blotting analysis. The 2.2-kb mRNA is first detected at late cleavage stages and rapidly accumulates as the primary mesenchyme forms, reaching an apparent maximum concentration in the late gastrula and pluteus stages. The cDNA was also used to identify the cells that contain the transcripts by hybridization in situ. Hybridization to cellular transcripts is first detected in primary mesenchyme cells as they enter the blastocoel, and transcripts are confined to these cells during spicule formation and subsequent development.

Animals↗
PubMed1987

The treatment of secondary orgasmic dysfunction II.

This study investigated the impact of group treatment on women with secondary orgasmic dysfunction and their partners. Eleven couples received 4 hours of basic sex education, after which seven of the couples received a Combination treatment format consisting of communication skills followed by sexual skills, while four of the couples received the opposite sequence. No significant differences were found between the two sequences. When compared with similarly recruited control couples in a previous study, a significantly greater number of treated women reached or exceeded the 50% criterion for coital orgasmic functioning after treatment. Couples who reported a better relationship adjustment prior to treatment reported a significantly greater gain in total sexual harmony than did less adjusted couples. Across the treatment conditions, women who had reached coital orgasm prior to treatment reported a significantly greater increase in relationship adjustment between the post-sex education and 6-month follow-up testing periods than women who had never reached coital orgasm. Some discrepancies in outcome were found in comparison with our earlier study, suggesting that subject heterogeneity may influence differential outcomes.

Adult↗
PubMed1987

Group treatment of secondary erectile dysfunction.

The effects of three group treatment formats on 20 men with secondary erectile dysfunction and their partners were contrasted. After a comprehensive medical and psychological screening, each couple was assigned to one of three treatment groups (Communication Technique Training, Sexual Technique Training, Combination Treatment) or to one of two control groups (Attention-Placebo, No-Treatment). Couples in the three treatment groups and the attention-placebo group participated in their respective formats in twice-weekly sessions for a total of 20 hours. The no-treatment control group received sex education and treatment after a 5-week waiting list period. All three treatment groups fostered substantial gains so that between-format differences were not statistically significant. Subject variables which predicted success/experience ratio gains included age of the male partner, perceived level of relationship adjustment, and the male partner's success/experience ratio prior to treatment. Eighty-one percent of the treated men reached the criterion of 80% or greater success/experience ratio (successful penetration and subsequent ejaculation) at the 6-month follow-up. Good nocturnal tumescence prior to treatment was correlated with a better treatment outcome than poor tumescence.

Adult↗
PubMed1987

Prosthetic valve endocarditis caused by Acinetobacter calcoaceticus subsp. lwoffi.

Acinetobacter spp. are uncommon etiologic agents of prosthetic valve endocarditis. Two patients with Acinetobacter calcoaceticus subsp. lwoffi prosthetic valve endocarditis are described. The patients were successfully treated with antibiotics (cefotaxime sodium and gentamicin sulfate); thus, we suggest medical treatment rather than early valve replacement in this particular type of infection.

Acinetobacter Infections↗
PubMed1986

Discrete catalytic sites for quinone in the ubiquinol-cytochrome c2 oxidoreductase of Rhodopseudomonas capsulata. Evidence from a mutant defective in ubiquinol oxidation.

A non-photosynthetic mutant (Ps-) of Rhodopseudomonas capsulata, designated R126, was analyzed for a defect in the cyclic electron transfer system. Compared to a Ps+ strain MR126, the mutant was shown to have a full complement of electron transfer components (reaction centers, ubiquinone-10, cytochromes b, c1, and c2, the Rieske 2-iron, 2-sulfur (Rieske FeS) center, and the antimycin-sensitive semiquinone). Functionally, mutant R126 failed to catalyze complete cytochrome c1 + c2 re-reduction or cytochrome b reduction following a short (10 microseconds) flash of actinic light. Evidence (from flash-induced carotenoid band shift) was characteristic of inhibition of electron transfer proximal to cytochrome c1 of the ubiquinol-cytochrome c2 oxidoreductase. Three lines of evidence indicate that the lesion of R126 disrupts electron transfer from quinol to Rieske FeS: 1) the degree of cytochrome c1 + c2 re-reduction following a flash is indicative of electron transfer from Rieske FeS to cytochrome c1 + c2 without redox equilibration with an additional electron from a quinol; 2) inhibitors that act at the Qz site and raise the Rieske FeS midpoint redox potential (Em), namely 5-undecyl-6-hydroxy-4,7-dioxobenzothiazole or 3-alkyl-2-hydroxy-1,4-napthoquinone, have no effect on cytochrome c1 + c2 oxidation in R126; 3) the Rieske FeS center, although it exhibits normal redox behavior, is unable to report the redox state of the quinone pool, as metered by its EPR line shape properties. Flash-induced proton binding in R126 is indicative of normal functional primary (QA) and secondary (QB) electron acceptor activity of the photosynthetic reaction center. The Qc functional site of cytochrome bc1 is intact in R126 as measured by the existence of antimycin-sensitive, flash-induced cytochrome b reduction.

Antimycin A↗
PubMed1986

Treatment of secondary orgasmic dysfunction: an outcome study.

This study investigated the differential effectiveness of various treatment formats for 55 couples in which the woman reported secondary orgasmic dysfunction (defined as the inability of the woman to reach orgasm during intercourse, with or without clitoral stimulation, more than 50% of the time for the last 5 months). Couples received two 2-hr sessions of sexual reeducation and were then assigned into one of four treatment conditions (a communication skills format, a sexual skills format, one of two combination formats) or into one of two control conditions (an attention-comparison control condition which consisted of didactic presentations, or a waiting-list control condition). Treatment was conducted by one of two female clinical psychologists in groups of between four to six couples. No significant differences were found between the different treatment conditions at the posttest or at the 6-month follow-up. Statistical comparisons conducted between the combined treatment and combined control conditions showed that the couples who received treatment reported significantly less overall sexual dissatisfaction and significantly greater sexual harmony at the posttest; however, these differences became nonsignificant at the follow-up. In comparison with the women in the control conditions, a significantly greater number of women who received treatment reached or exceeded the project's 50% criterion for coital orgasmic functioning at the posttest; however, these differences became nonsignificant at the follow-up. Couples who reported less relationship adjustment prior to treatment showed greater overall gains in coital orgasmic frequency than couples who reported better relationship adjustment.

Adult↗
PubMed1986

Unstable angina pectoris evolving to acute myocardial infarction: significance of ECG changes during chest pain.

We retrospectively evaluated 32 patients with unstable angina (UA) and no evidence of increased oxygen demand during episodes of chest pain (no significant changes in heart rate and blood pressure), who developed an acute myocardial infarction (AMI) during the same hospitalization. Based on the type of ST changes during anginal pain, two groups were defined: Group A included 19 patients who developed ST elevation during AMI; 15 of these 19 patients (79%) were in Killip class I, two were in class II, and there was one patient each in classes III and IV, respectively. Only one of the 19 patients died. Group B included 13 patients who developed ST depression during AMI; nine of these 13 patients were in Killip class IV and the remaining four patients died before they could be evaluated. Ten patients died (77%) (p less than 0.01), seven in electromechanical dissociation and three in cardiogenic shock. Postmortem examination, performed in four patients, revealed total obstruction of the left main coronary artery. It is concluded that patients with UA who, during attacks of chest pain, develop ST depression and no evidence of increased oxygen demand may have a poor prognosis when they develop an AMI. This selected group of high-risk patients appears to need immediate intensive medical care and most probably early surgical treatment.

Adolescent↗
PubMed1986

Unstable angina: the significance of ST segment elevation or depression in patients without evidence of increased myocardial oxygen demand.

We evaluated 46 patients with unstable angina (UA), who showed no significant changes in heart rate, blood pressure, and double product (as evidence of increased oxygen demand) during episodes of chest pain. Coronary angiography was performed in all patients during the same hospitalization. Of 26 patients with UA and ST depression (group A), 10 had left main coronary artery disease (CAD) and eight had left main equivalent CAD. Of 20 patients with UA and ST elevation (group B), only one had left main CAD and one had left main equivalent CAD. All patients in group A had ST depression in leads V4 and V5, and all patients in group B had ST elevation in leads V2 and V3. The presence of ST depression in leads V4 and V5 in UA patients without evidence of increased oxygen demand may be suggestive of significant left main or left main equivalent CAD. Therefore, coronary angiography is recommended during the same hospitalization.

Adult↗
PubMed1986

Cytochrome c(2) is not essential for photosynthetic growth of Rhodopseudomonas capsulata.

The structural gene for cytochrome c(2) (cycA) of the photosynthetic bacterium Rhodopseudomonas capsulata has been cloned, and the nucleotide and deduced polypeptide sequences have been determined. Compared with the known amino acid sequence of the purified cytochrome c(2), the nucleotide sequence corresponding to the N-terminal part of the cycA gene product indicates the presence of a putative 21 amino acid signal sequence. Thus, cytochrome c(2) may be synthesized as a precursor which is processed during its secretion to the periplasm. Insertion and insertion-deletion mutations were constructed in vitro and the chromosomal cycA(+) allele of a wild-type strain was replaced with these mutations by homologous recombination to yield c(2) (-) mutants of R. capsulata. The c(2) (-) mutants are stable, and they can grow by photosynthesis and by respiration. Since cytochrome c(2) is the primary electron donor to the reaction center during photosynthesis, the ability of these mutants to grow photosynthetically indicates that an alternative way(s) of reducing the oxidized reaction center must exist in R. capsulata. One candidate for this role may be the membrane-bound cytochrome c(1).

Journal Article↗
PubMed1986

Perspectives of sex therapy outcome: a survey of AASECT providers.

Randomly selected AASECT members who reported that they conduct sex therapy (N = 289) responded to a questionnaire about their sex therapy caseloads. Desire discrepancies between partners was the most common problem (31%). Least commonly reported problems were vaginismus (5%), ejaculatory inhibition (5%), and primary erectile dysfunction (2%). Highest success rates (client satisfaction with sexual functioning) were for premature ejaculation (62%), secondary orgasmic dysfunction (56%), and desire discrepancies (53%). Primary erectile dysfunctions had the lowest success rate (25%). The most commonly used treatment methods were a focus on communication skills, general sex education, homework assignments, and a focus on the sexual interaction; sensate focus, and the discussion of nonsexual individual and/or relationship issues also were quite commonly used. From a discriminant function analysis, the combined Therapists and Multiple-certified provider groups reported focusing on sexual interactions more than the combined Counselors and Educators; the Educators were the least likely providers to use a focus either on sexual interactions or on homework assignments. The Counselors were the most likely, and the Educators the least likely, to use communication skills. Therapists and the Multiple-certified providers estimated higher treatment success rates than Counselors and Educators for premature ejaculation, secondary erectile dysfunction, vaginismus, primary orgasmic dysfunction, sexual avoidance, ejaculatory inhibition, and sexual arousal problems. The Educators were the least successful with dyspareunia. Educators and Counselors were similar in reporting the fewest clients with sexual arousal problems. Therapists and Multiple-certified providers reported spending more treatment hours with desire discrepancies and desire problems. The implications of the findings for clinical practitioners and researchers are discussed.

Communication↗
PubMed1985

Social environmental predictors of children's adjustment in elementary school classrooms.

Relationships between qualities of the perceived social environment and children's adjustment were examined in 30 second- to fourth-grade classrooms. Based on Moos' conceptual framework, social environment was assessed from both teachers' and children's perspectives. There was little agreement between the two views. Nine teacher- and peer-rated adjustment variables were used as criterion measures in multiple regression analyses which controlled for the potential confounding influence of grade level and family income. The main substantive findings were that peer sociometric ratings were more positive at lower grade levels and in classes rated by children as high in Order and Organization; teachers rated less acting-out behavior in classes seen by children as high in Affiliation, Teacher Control, and Task Orientation; and teachers rated children as more likeable in classes seen by Children as high in Teacher Control and Competition. Implications of the study's findings for future primary preventive efforts to engineer health-promoting classroom environments are discussed.

Child↗
PubMed1985

Amiodarone-induced sinoatrial block.

We observed sinoatrial block due to chronic amiodarone administration in a 5-year-old boy with primary cardiomyopathy, Wolff-Parkinson-White syndrome and supraventricular tachycardia. Reduction in the dosage of amiodarone resulted in the disappearance of the sinoatrial block and the persistence of asymptomatic sinus bradycardia.

Amiodarone↗
PubMed1984

Elevation of serum lactic dehydrogenase levels as an early marker of occult malignant lymphoma.

Elevated serum lactic dehydrogenase (LDH) levels, 595 to 615 microns/ml (normal less than 225 microns/ml) with predominance of LDH isoenzymes 2 and 3 was the early and only sign of occult malignant lymphoma in three patients. In the first patient, overt lymphoma appeared clinically only 2 months after the finding of elevated serum LDH levels, whereas in the other two asymptomatic patients, pathologic LDH levels were the only clues to the need for further diagnostic investigation. It is concluded that LDH may have a diagnostic value in the preclinical stage of malignant lymphoma. Thus, a patient with no apparent cause for elevated serum LDH levels warrants a thorough work-up including abdominal CT scan and even explorative laparotomy.

Adult↗
PubMed1984

Depression of the synthesis of the intermediate and large forms of ribulose-1,5-bisphosphate carboxylase/oxygenase in Rhodopseudomonas capsulata.

Rhodopseudomonas capsulata produces both an intermediate (I) and a large (L) form of ribulose-1,5-bisphosphate carboxylase/oxygenase. Both forms are derepressed under CO2-limiting conditions. The L-form of the enzyme is completely repressed when the culture is grown either photoautotrophically or photoheterotrophically with malate as the electron donor. The L-form is derepressed in the late logarithmic phase of growth when cells are grown photoheterotrophically with butyrate as the electron donor and the NaHCO3 supplement is 0.01%. The level of the I-form is increased about fivefold under latter growth conditions when compared to malate-grown cells. Analytical ultracentrifugation revealed the molecular masses of the I- and L-forms to be 300,000 and 542,000, respectively. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed the I-form to be composed of only one type subunit with a molecular weight of 64,000. The L-form possessed both large and small subunits with molecular weights of 58,000 and 10,000.

Bicarbonates↗