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Biomedical subjects

J Steiner

Publications and source records attributed to J Steiner.

At least 55 records · Page 3Linked to original sources
PubMed1996

Polychaetoid is required to restrict segregation of sensory organ precursors from proneural clusters in Drosophila.

Reduction of wild-type activity of the polychaetoid (pyd) gene results in formation of extra mechanosensory bristles on the head and notum of adult Drosophila. Loss of pyd function results in decreased ability to restrict sensory organ precursor (SOP) formation to a single cell per proneural cluster. Although the initial proneural cluster pattern of achaete expression is not altered in pyd mutants, extra cells within proneural clusters express the high levels of achaete characteristic of SOPs. This observation suggests that pyd+ functions as a negative regulator of achaete-scute complex expression within the proneural cluster. Synergistic interactions between pyd and Notch, Delta and extramacrochaetae mutations support this model. We also demonstrate that pyd is required for normal eye development.

Alleles↗
PubMed1996

Torsional properties of stainless steel and nickel-titanium endodontic files.

The torsional properties of stainless steel (SS) endodontic files (Flex-O-File; Maillefer/L. D. Caulk Co., Milford, DE) and recently developed nickel-titanium (NiTi) endodontic files (Quality Dental Products, Inc., Johnson City, TN) were compared. File sizes 15, 25, 35, 45, and 55 were subjected to torsional load in clockwise (CW) and counterclockwise (CCW) directions independently. Results showed that SS files had a significantly greater rotation to failure in the CW direction, whereas the NiTi files had a significantly greater rotation to failure in the CCW direction. Despite these differences in rotation to fracture, there was essentially no difference between the SS and NiTi instruments in the torque that it took to cause failure in both the CW and the CCW directions. Therefore, whereas the number of CW and CCW rotations to failure differed for the two instruments, the actual force that it took to cause that failure was the same.

Alloys↗
PubMed1996

Chart reviews in emergency medicine research: Where are the methods?

STUDY OBJECTIVE: Medical chart reviews are often used in emergency medicine research. However, the reliability of data abstracted by chart reviews is seldom examined critically. The objective of this investigation was to determine the proportion of emergency medicine research articles that use data from chart reviews and the proportions that report methods of case selection, abstractor training, monitoring and blinding, and interrater agreement. METHODS: Research articles published in three emergency medicine journals from January 1989 through December 1993 were identified. The articles that used chart reviews were analyzed. RESULTS: Of 986 original research articles that were identified, 244 (25%; 95% confidence interval [CI], 22% to 28%) relied on chart reviews. Inclusion criteria were described in 98% (95% CI, 96% to 99%), and 73% (95% CI, 67% to 79%) defined the variables being analyzed. Other methods were seldom mentioned: abstractor training, 18% (95% CI, 13% to 23%); standardized abstraction forms, 11% (95% CI, 7% to 15%); periodic abstractor monitoring, 4% (95% CI, 2% to 7%); and abstractor blinding to study hypotheses, 3% (95% CI, 1% to 6%). Interrater reliability was mentioned in 5% (95% CI, 3% to 9%) and tested statistically in .4% (95% CI, 0% to 2%). A 15% random sample of articles was reassessed by a second investigator; interrater agreement was high for all eight criteria. CONCLUSION: Chart review is a common method of data collection in emergency medicine research. Yet, information about the quality of the data is usually lacking. Chart reviews should be held to higher methodologic standards, or the conclusions of these studies may be in error.

Data Collection↗
PubMed1996

Purification and characterization of two acetyl xylan esterases from Penicillium purpurogenum.

Penicillium purpurogenum produces several enzymes active in xylan hydrolysis, of there, the acetyl xylan esterase (AXE) activity secreted by the fungus has now been studied. The amount of activity obtained in the culture is related to the degree of acetylation of the carbon source used, the best being chemically acetylated xylan. AXE was concentrated from culture supernatants by ultrafiltration and (NH4)2SO4 precipitation and fractionated by gel filtration in Bio-Gel P-300. Two peaks of activity (AXE I and AXE II) were obtained. These two enzymes were further purified separately to homogeneity by chromatography in CM-Sephadex C-50 and chromatofocusing. AXE I (M(r) 48,000) has a pl of 7.5, while AXE II (M(r) 23,000) has a pl of 7.8. Optimal enzyme activity was at pH 5.3 and 50 degrees C for AXE I and pH 6.0 and 60 degrees C for AXE II. Both enzymes are active towards several acetylated substrates. Antisera against the two enzymes do not cross-react, and the N-terminal sequences of AXE I and II do not show similarities. These results suggest that AXE I and AXE II are the products of different genes.

Acetylesterase↗
PubMed1996

Revenge and resentment in the 'Oedipus situation'.

The author considers an important form of 'psychic retreat' to be based on resentment and grievance. In this paper he discusses how resentments can build up and be nursed when the impulse to violence and in particular revenge is prevented from being expressed. The resentment leads to an impasse from which it is difficult for the analyst and patient to extricate themselves. A clinical example illustrating such an impasse is discussed. Then extracts from 'Kidnapped' by Robert Louis Stevenson are used to illustrate ways in which resentment can be relinquished and replaced with forgiveness. It is argued that the issue of revenge has to be negotiated before such a transformation can result.

Adult↗
PubMed1996

The aim of psychoanalysis in theory and in practice.

The aims of psychoanalysis are reviewed in terms of theories of mental function and structure. The theory of mental conflict remains the central theory of classical psychoanalysis but has been deepened and supplemented by newer theories. In particular the theory of projective identification has radically altered our view of mental structure and function and has allowed us to reformulate the aims of psychoanalysis in terms of the re-acquisition and re-integration of projected parts of the self. The central role of mourning in this process is discussed, and some of the obstacles to progress are reviewed. It is suggested that oedipal resentments may play a central role in the creation of impasse.

Defense Mechanisms↗
PubMed1995

Penicillium purpurogenum produces several xylanases: purification and properties of two of the enzymes.

The fungus Penicillium purpurogenum produces several extracellular xylanases. The two major forms (xylanases A and B) have been purified and characterized. After ammonium sulfate precipitation and chromatography in Bio-Gel P 100, xylanase A was further purified by means of DEAE-cellulose, hydroxylapatite and CM-Sephadex, and xylanase B by DEAE-cellulose and CM-Sephadex. Both xylanases showed apparent homogeneity in SDS-polyacrylamide gel electrophoresis. Xylanase A (33 kDa) has an isoelectric point of 8.6, while xylanase B (23 kDa) is isoelectric at pH 5.9. Antisera against both enzymes do not cross-react. The amino terminal sequences of xylanases A and B show no homology. The results obtained suggest that the enzymes are produced by separate genes and they may perform different functions in xylan degradation.

Amino Acid Sequence↗
PubMed1994

Effect of acadesine, a new metabolic agent, on exercise-induced myocardial ischemia in chronic stable angina.

Acadesine, the first of a class of adenosine-regulating agents, has been shown to possess antiischemic properties in animal models. The aim of the study was to assess the effect of acadesine on exercise-induced myocardial ischemia in patients with chronic stable angina pectoris. Twelve patients with stable angina entered a five-way, randomized double-blind study comparing the effects of four doses of acadesine with placebo on time to 1 mm ST-segment depression and other parameters of exercise tolerance. At each study period patients underwent baseline exercise testing, followed by drug or placebo infusion after a 60 minute rest period. The exercise test was repeated after 30 minutes infusion, which continued throughout recovery. Time to angina, time to 1 mm ST depression, and total exercise time during the placebo infusion were 301.1 +/- 45.3, 314.8 +/- 50.9, and 399.4 +/- 47.6 seconds. The placebo-adjusted percentage change in time to 1-mm ST segment with acadesine 6, 12, 24, and 48 mg/kg was -0.1 +/- 6.2%, 11.1 +/- 13.8%, 12.9 +/- 8.6%, and -3.2 +/- 6.8%, respectively (p = NS vs. baseline). Time to angina, total exercise time, and recovery time of the ST segment were not consistently altered by acadesine. The lack of effect across all acadesine doses is consistent with animal data from ischemia-reperfusion injury studies, where a clear dose dependency was present with a loss of effect at higher doses. Alternatively, the extent of ischemia induced by treadmill exercise may have been insufficient for the antiischemic activity of acadesine to be evident.

Aged↗
PubMed1994

Interpretation: selected fact or overvalued idea?

The authors describe Bion's use of the notion of the 'selected fact' in the evolution of analytic interpretations. They draw attention to the similarity between the emergence of a 'configuration' from a selected fact and the crystallisation of delusional certainty from an 'overvalued idea'. The risks to the patient of the imposition of an overvalued idea is described. They emphasise the importance of monitoring the subsequent development in sessions following interpretations for evidence of conscious and unconscious reactions to it and offer clinical examples of the use of a selected fact in arriving at an interpretation and the unconscious use of an overvalued idea to form an interpretation and the subsequent analysis of its effects.

Adult↗
PubMed1992

Beta-glucosidase from Penicillium purpurogenum: purification and properties.

beta-Glucosidase was purified from the culture supernatant of Penicillium purpurogenum. The purified enzyme was homogeneous on both nondenaturing and sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis. The enzyme is a monomeric glycoprotein with M(r) of 90,000 as determined by gel filtration on Bio-Gel P-300 and SDS-polyacrylamide gels. Two enzyme forms were resolved by chromatofocusing and isoelectric focusing, and the pI values obtained with both methods were 4.2 (major form) and 6.0. The major form was characterised further. Enzyme activity was optimal at pH 3.5 and at 60 degrees C. The enzyme was stable in the pH range 2.5-9.5 for 24 h at 4 degrees C. Kinetic analysis gave Kms of 0.8 mM for cellobiose and 85 microM for p-nitrophenyl-beta-D-glucopyranoside. The enzyme hydrolyses a wide range of substrates including aryl-beta-glucosides, cellobiose, and amygdalin. Glucose inhibits competitively and glucono-delta-lactone is a mixed inhibitor of the enzyme.

Cellobiose↗
PubMed1991

Initial and steady state pharmacokinetics of cilazapril in congestive cardiac failure.

Twenty one patients with NYHA class II-III congestive heart failure received single ascending doses of 0.5, 1.25 and 2.5 mg cilazapril daily followed by the minimum effective dose for six weeks. Fifteen patients completed the study, but the data from only 11 were sufficiently complete for kinetic evaluation. The pharmacokinetics of the metabolite, cilazaprilat, after a single dose of 0.5 mg cilazapril were similar to previous observations in healthy volunteers at identical dosage. Repeat administration, however, led to greater accumulation than previously observed in volunteers at the higher dosages of 1.25 or 5 mg given for 8 days. Seven patients experienced adverse events. Four were severe, leading to withdrawal of the patients from the study, but only one event was related to cilazapril. Of the other three, one suffered a myocardial infarction and subsequently died due to worsening congestive heart failure. One other patient was withdrawn with two adverse events probably related to cilazapril. No other deaths occurred amongst the study population, and there were no significant abnormalities in haematology or blood chemistry.

Adult↗
PubMed1991

A psychotic organization of the personality.

Clinical material is presented to illustrate the difference between psychotic and non-psychotic organizations of the personality. It is suggested that the psychotic part of the personality strives to possess and control its objects because it needs them to repair a damaged ego. The nonpsychotic part on the other hand is able to face reality sufficiently to relinquish its objects and mourn them. The interaction between the two parts in the same patient is discussed.

Humans↗
PubMed1990

Pathological organizations as obstacles to mourning: the role of unbearable guilt.

A patient is described who made moves to face his internal and external reality only to find that this put him in touch with an internal world in a horrific state. The horror resulted from his view of damaged and imprisoned objects which arose from the way his defences were organized into a pathological organization of the personality which controlled his objects with ruthlessness and cruelty. As he began to loosen his dependence on the organization and to face his internal situation, depressive anxieties became prominent and of these he found guilt particularly unbearable. In order to escape from guilt he retreated once more to the protection of the organization and it is this which prevented him mourning his lost objects. It is argued that it is in the process of mourning that lost parts of the self are regained and it is specifically this process which was interfered with by the pathological organization.

Defense Mechanisms↗
PubMed1989

An assessment of tenoxicam, a nonsteroidal anti-inflammatory drug of long half-life, in patients with impaired renal function suffering from osteoarthritis or rheumatoid arthritis.

Fifty-eight patients, aged 48-87 years, with impaired renal function and mean initial creatinine clearance of 52.1 mls/min were recruited to a 12-week open study of tenoxicam 20 mg/day for osteoarthrosis or rheumatoid arthritis. Renal function was measured before and after a brief run-in period when patients discontinued all nonsteroidal anti-inflammatory drugs, taking paracetamol alone, prior to monthly monitoring thereafter. Fifty-four % of patients completed the study, the others being withdrawn from lack of efficacy (17%), adverse events (24%) or both (5%). During the run-in period the mean creatinine clearance of 28 patients completing the trial improved to 64.7 mls/min and then dropped to 57.9 mls/min during the course of 12 weeks treatment with tenoxicam. Serial analysis of haematological and biochemical safety parameters showed no drug-induced change of significance. Twenty-three% of patients felt worse and 45% better at the end of treatment. Seventeen patients withdrew because of adverse events. These were normally gastrointestinal and always unrelated to further deterioration in renal function. Tenoxicam, 20 mg/day, can be given safely for a period of at least three months in patients with mild or moderate renal impairment.

Aged↗