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Biomedical subjects

G Frank

Publications and source records attributed to G Frank.

At least 109 records · Page 6Linked to original sources
PubMed1993

On the validity of hypotheses derived from the Rorschach: the relationship between shading and anxiety, update 1992.

Research on the hypothesis that shading responses on the Rorschach reflect how people deal with their anxiety was reviewed. The research does not lend support to the hypothesis, but serious methodological and conceptual problems with this research make it difficult to assess the meaning of the results of these studies. The nature of needed research is discussed.

Adaptation, Psychological↗
PubMed1993

C' and depression.

Research assessing the validity of the Rorschach hypothesis that achromatic responses (C') reflect depressiveness was reviewed. The conclusions drawn from these data are that the research does not support the hypothesis as stated and research is needed to clarify the relationship of depressiveness to the determinants or the psychological meaning of C'. Until such time as objective signs of depression and depressiveness can be discovered by research, clinicians should not interpret C' as signifying depressiveness. If the search is for assistance in discerning depressiveness from the analysis of Rorschach data, until a more objective and valid method of such assessment is developed, the presence of depressive content would appear to be a satisfactory method of assessing a person's depressiveness.

Color Perception↗
PubMed1993

On the validity of hypotheses derived from the Rorschach: the relationship between color and affect, update 1992.

A review of research since the last review in 1976 reconfirms the conclusion that how persons will express their emotions does not necessarily bear any relationship to the nature of their responses to color on the Rorschach. It is not only time for clinicians to give up this color-affect hypothesis with regard to Rorschach data but to conduct some basic, exploratory research to examine, empirically, whether a relationship does exist between persons' characteristic modes of expressing their emotions and their characteristic styles of responding to the Rorschach.

Affect↗
PubMed1993

Use of the Rorschach to predict whether a person would benefit from psychotherapy.

Research on the use of the Rorschach in predicting response to psychotherapy was reviewed. The research indicates that form level turns out to be the variable which was related to response to treatment, psychiatric as well as psychological, and provided as much information regarding prognosis as could be derived from either the Beck or Klopfer Prognostic Indices. The kind of research now needed in this area of study was discussed.

Humans↗
PubMed1993

On the meaning of movement responses on the Rorschach.

Research assessing the presumed meanings of M, FM, or m was examined. Since the research did not support the presumed meanings of M, FM, or m, it could be concluded that any interpretation of the psychological meaning of these movement responses is being done on the basis of unsubstantiated belief. Strategies of research to explore the meaning(s) of the various movement responses were discussed.

Adolescent↗
PubMed1993

[Exacerbation of autoimmune hypothyroidism after hemi-hypophysectomy in a patient with Cushing's disease].

A 41 year old woman affected by Cushing's disease underwent hemi-hypophysectomy with removal of an ACTH secreting microadenoma. Forty days later, when normal ACTH, cortisol plasma levels and urinary cortisol levels were restored, features of primary autoimmune hypothyroidism developed. While cortisol levels were elevated serum thyroid hormone levels were normal, serum hormone TSH was at the upper limit of the normal range and serum antimicrosomal antibodies were slightly elevated. It is likely that hypothyroidism already present before surgery was not clinically evident due to the immunosuppressive effect of high cortisol levels. The need to assess thyroid function in patient with hypercortisolism is emphasized with the aim to identify the possible onset of autoimmune thyroid disease when cortisol levels are normalized.

ACTH Syndrome, Ectopic↗
PubMed1993

Sensitive detection of the activation state of blood coagulation in porcine DIC models by a new fibrin immunoassay.

Elevated levels of soluble fibrin in plasma indicate that thrombin converts fibrinogen to fibrin without sufficient inhibitory control. Therefore, measurement of soluble fibrin (SF) in plasma may be considered as a laboratory test for intravascular coagulation. We have demonstrated that a new immunoassay for detection of SF in human plasma (Lill et al., Blood Coag Fibrinol 1993; 4: 97-102), based on a fibrin specific monoclonal antibody, also detects porcine SF with high sensitivity. Thrombin-dependent generation of SF in porcine plasma in vitro resulted in increased reactivity of the assay system, which was time and dose dependent. Dextran sulphate (DXS) and bacterial lipopolysaccharide (LPS) were used as stimuli in in vivo experiments in pigs. Plasma levels of SF increased steadily after intravenous administration of DXS (5 mg/kg for 1 h) to 38 +/- 7.8 micrograms/ml (mean +/- SEM) at 2 h, whereas LPS (2 micrograms/kg/h for 6 h) markedly increased plasma SF levels to over 120 micrograms/ml (at 6 h) after a lag phase of 2 h. In conclusion, this new immunoassay for human fibrin allows specific and sensitive detection of soluble fibrin in porcine plasma.

Animals↗
PubMed1992

Characterization of chlorophyll a/b proteins of photosystem I from Chlamydomonas reinhardtii.

In this study we have isolated the chlorophyll a/b-binding proteins from a photosystem I preparation of the green alga Chlamydomonas reinhardtii and characterized them by N-terminal sequencing, fluorescence, and absorption spectroscopy and by immunochemical means. The results indicate that in this organism, the light-harvesting complex of photosystem I (LHCI) is composed of at least seven distinct polypeptides of which a minimum number of three are shown to bind chlorophyll a and b. Both sequence homology and immunological cross-reactivity with other chlorophyll-binding proteins suggest that all of the LHCI polypeptides bind pigments. Fractionation of LHCI by mildly denaturing methods showed that, in contrast to higher plants, the long wavelength fluorescence emission typical of LHCI (705 nm in C. reinhardtii) cannot be correlated with the presence of specific polypeptides, but rather with changes in the aggregation state of the LHCI components. Reconstitution of both high aggregation state and long wavelength fluorescence emission from components that do not show these characteristics confirm this hypothesis.

Amino Acid Sequence↗
PubMed1992

Allosteric characteristics of GTP cyclohydrolase I from Escherichia coli.

The kinetic and regulatory properties of GTP cyclohydrolase I were investigated using an improved enzyme assay and direct determination of the product, dihydroneopterin triphosphate. The enzyme was purified from Escherichia coli to absolute homogeneity as demonstrated by N-terminal sequencing of up to 50 amino acid residues. A 30-residue internal fragment showed 42% similarity with rat liver GTP cyclohydrolase I. The enzyme did not obey Michaelis-Menten kinetics or show a sigmoid reaction curve. The substrate saturation kinetics were found to be slow with low response to minor changes in GTP concentrations. GTP cyclohydrolase I has a relatively high apparent Km. The values are slightly different for enzyme purified by GTP-agarose (100 microM) and UTP-agarose (110 microM). Low turnover numbers of 12/min and 19/min were calculated for the respective enzyme preparations. GTP-cyclohydrolase-I activity was modulated in Vmax by K+, divalent cations, UTP and tetrahydrobiopterin. Divalent cations, such as Mg2+, had an activating effect with an optimum at 8 mM Mg2+. A different catalytic function and formation of a new, unidentified product by GTP cyclohydrolase I was observed in the presence of Ca2+. In the presence of 1 mM EDTA and Mg2+, GTP-cyclohydrolase-I activity was strongly inhibited by chelate complexes. UTP proved not to be a competitive inhibitor, but a positive modulator. The inhibition by chelate complexes was totally abolished by UTP. Tetrahydrobiopterin showed an inhibitory effect, with 50% inhibition at 100 microM tetrahydrobiopterin. UTP was able to reduce the inhibition by tetrahydrobiopterin. Using monoclonal antibody 1F11 (related to the GTP-binding site), and monoclonal antibody NS7 (mimicking tetrahydrobiopterin), different binding sites were demonstrated for GTP and tetrahydrobiopterin on each enzyme subunit. Western-blot competition analysis revealed a UTP-binding site different from the binding sites of GTP and tetrahydrobiopterin. Based on the kinetic behaviour and the kind of modulations observed we defined GTP cyclohydrolase I as an M-class allosteric enzyme.

Allosteric Regulation↗
PubMed1992

Phycobilisome structure in the cyanobacteria Mastigocladus laminosus and Anabaena sp. PCC 7120.

Phycobilisomes of the cyanobacteria Mastigocladus laminosus and Anabaena sp. PCC7120 differ from typical tricylindrical, hemidiscoidal phycobilisomes in three respects. Firstly, size comparisons of the core-membrane linker phycobiliproteins (LCM) in different cyanobacteria by SDS/PAGE reveal an apparent molecular mass of 120 kDa for the LCM of M. laminosus and Anabaena sp. PCC7120. This observation suggests that the polypeptides of these species have four linker-repeat domains. Secondly, phycobilisomes of M. laminosus are shown to contain at least three, but most probably four, different rod-core linker polypeptides (LRC). These LRC, which attach the peripheral rods to the core and thereby make phycocyanin/allophycocyanin contacts, have been identified and characterized by N-terminal amino acid sequence analysis. Additionally, electron microscopy of phycobilisomes isolated from M. laminosus and Anabaena sp. PCC7120 reveals similar structures which differ from those of Calothrix sp. PCC7601 with their typical six, peripheral rods. Based upon protein-analytical results and a reinterpretation of the data of [Isono, T. & Katoh, T. (1987) Arch. Biochem. Biophys. 256, 317-324], we discuss structural implications of recent findings on the established hemidiscoidal model for the phycobilisomes of M. laminosus and Anabaena sp. PCC7120. Up to eight peripheral rods are suggested to radiate from a modified core substructure which contains two additional peripheral allophycocyanin hexamer equivalents that serve as the core-proximal discs for two peripheral rods.

Amino Acid Sequence↗
PubMed1992

The primary structure of the antenna polypeptides of Ectothiorhodospira halochloris and Ectothiorhodospira halophila. Four core-type antenna polypeptides in E. halochloris and E. halophila.

Antenna polypeptides from two species of the family Ectothiorhodospiraceae have been investigated. By means of gel filtration and subsequent high-performance liquid chromatography, at least five polypeptides were isolated from each of Ectothiorhodospira halochloris and Ectothiorhodospira halophila. The majority of their primary structures was identified by Edman degradation. Comparison of these polypeptide sequences with the known primary structures of antenna polypeptides from various purple non-sulfur bacteria revealed interesting new aspects with regard to the structure of the core-peripheral antenna system. E. halochloris and E. halophila contain two pairs of alpha- and beta-polypeptides each with typical primary structure elements of core complexes, indicating a modified antenna complex organization.

Alkylation↗
PubMed1992

Secretion of mammalian ribonucleases from Escherichia coli using the signal sequence of murine spleen ribonuclease.

A nucleotide sequence identical with that of the recently identified murine pancreatic ribonuclease (RNAase) was isolated from a murine spleen cDNA library. Active RNAase was expressed and secreted from Escherichia coli lon-htpr- transformed with a plasmid containing the E. coli trp promoter followed by the murine RNAase gene sequence, including the original eukaryotic 26-amino-acid signal sequence. Approx. 1 mg of properly matured RNAase protein/litre was secreted into the medium of a fermentor culture after the promotor was induced by tryptophan starvation. When the signal sequence was deleted from the plasmid, intracellular RNAase activity was very low and there was no significant supernatant RNAase activity. Even higher RNAase yields were obtained with a synthetic gene for bovine pancreatic ribonuclease cloned after the signal sequence of the murine gene. About 2 mg of correctly processed RNAase A/litre was isolated from the growth medium, and a further 8-10 mg of correctly processed RNAase/litre could be isolated from the soluble fraction of the cells. Thus this eukaryotic signal sequence is both recognized by the E. coli transport and processing apparatus and gives efficient secretion, as well as export, of active, mature mammalian RNAases.

Amino Acid Sequence↗
PubMed1992

Three C-phycoerythrin-associated linker polypeptides in the phycobilisome of green-light-grown Calothrix sp. PCC 7601 (cyanobacteria).

Microanalyses by SDS-PAGE and microsequencing demonstrate that, under green-light conditions, 3 C-phycoerythrin associated rod-linker polypeptides with different N-terminal amino acid sequences are present in phycobilisomes (PBS) from Calothrix sp. 7601 cells. Two of these polypeptides, corresponding to SDS-PAGE bands at 36 and 37 kDa, could be assigned, respectively, to the cpeC and cpcD genes found on a separate cpeCD-operon in Calothrix sp. 7601 (Federspiel, N.A. and Grossman, A.R. (1990) J. Bacteriol, 172, 4072-4081). The third C-PE rod-linker polypeptide, LR,2PE,33, requires, therefore, a third gene with the suggested locus designation 'cpeE'. A C-PE (alpha beta)6-LR,2PE,33 complex containing this third rod-linker polypeptide could be isolated from phycobilisomes and characterized. PBS from both green- and red-light cells of Calothrix contain a single, unique LRC28 rod-core linker polypeptide which is not altered during chromatic adaptation.

Amino Acid Sequence↗
PubMed1992

Role of mapping-guided surgery in patients with recurrent ventricular tachycardia.

To assess the value of ventricular tachycardia (VT) surgery 108 patients with recurrent episodes of VT were studied. There were 97 patients with coronary artery disease (group I) and 11 patients without coronary artery disease (group II). All patients in group I underwent subendocardial resection; 12 patients also underwent cryoablation. Cryoablation alone was performed in all patients in group II. During a mean follow-up period of 40 +/- 27 months, 29 patients (30%) in group I and two patients (18%) in group II died (p = 0.33). There were nine patients (9%) in group I and six patients (55%) in group II who had nonfatal recurrences of VT after surgery (p less than 0.01). In group I, there was a higher mortality rate among patients who had VT of posterolateral origin (14 of 31 patients; 45%) compared with 3 of 11 patients (28%) who had VT of anterolateral origin, 1 of 8 patients (12%) who had VT of inferoseptal, and 11 of 39 (29%) patients who had VT of anteroseptal origin. None of the eight patients with two distinct origins of VT died.

Adult↗
PubMed1992

Surgical therapy for drug-refractory ventricular tachycardia: role of additional aneurysmectomy or bypass grafting.

To assess whether additional aneurysmectomy and/or bypass grafting influence prognosis we studied 97 patients with recurrent sustained monomorphic ventricular tachycardia after an old myocardial infarction. All patients underwent subendocardial resection due to drug-refractory ventricular tachycardia. There were 41 patients who had resection alone, 27 patients had resection and aneurysmectomy, 13 patients had resection and bypass grafting and the remaining 16 patients had resection with both, aneurysmectomy and bypass grafting. During the mean follow-up of 40 +/- 27 months 29 patients died (30%) (total mortality), 7 patients suddenly (7%) and 20 patients from cardiac causes (20%). There were no significant differences in total mortality between patients with resection alone (32%), patients with resection and aneurysmectomy (22%), patients with resection and bypass grafting (31%) and patients who had resection, aneurysmectomy and bypass grafting (38%). In addition, no significant differences were observed in the incidence of sudden death and nonfatal recurrences between patients with resection alone: sudden death 12%, recurrences 7%; patients with resection and aneurysmectomy: sudden death 0%, recurrences 19%; patients with resection and bypass grafting: sudden death 0%, recurrences 8%; and patients with resection, aneurysmectomy and bypass grafting: sudden death 13%, recurrences 0%. Postoperatively, left ventricular function improved in 56% of patients who had resection and aneurysmectomy compared to 17% of patients with resection alone, 31% of patients with resection and bypass grafting and 19% of patients who had resection, aneurysmectomy and bypass grafting. There is a low risk of sudden death and nonfatal recurrences after subendocardial resection. An influence of additional surgical approaches (aneurysmectomy or bypass grafting) on prognosis is not visible.

Adult↗
PubMed1992

The response of African Americans to the Rorschach: a review of the research.

Studies exploring the performance of African Americans on the Rorschach were reviewed. The review revealed the limited number of studies done in this area of study, as well as the fact that the research paradigm for all of this research has been limited to comparing the Rorschach performance of African Americans to that of Whites. However, no one has offered a rationale for such a research paradigm. Without a scientific reason to expect personality to be a function of race, another research design was recommended, one that explores the effect of a variety of aspects of living conditions on the development of the personality of African Americans.

Black or African American↗