Tumour size distribution in mammography screening

Many mammography screening programmes have not been able to show higher percentages of small invasive cancers detected at subsequent screens than at initial screens. This has been a matter of serious concern as it contradicts the very theory of screening. Based on data from the county of Fyn, Denmark we evaluated the distribution based on point estimates, as well as on the entire tumour size distribution. The programme changed the amount of tumours less than 15 or 20 mm, but did not change the amount of tumours less than 10 mm. We evaluated the entire tumour size distribution and found that screen number was the only significant factor, implying that the number of screens changed the tumour size distribution. We recommend that the entire tumour size distribution is used to evaluate the ability of a programme to detect small breast cancers, instead of only point estimates as has previously been the practice.

Breast cancer incidence after the start of mammography screening in Denmark

Mammography screening may lead to overdiagnosis of asymptomatic breast cancers, that would otherwise not have given rise to clinical symptoms. This aspect was studied in three regional screening programmes in Denmark, which started in Copenhagen municipality, Fyn county, and Frederiksberg municipality in 1991, 1993, and 1994, respectively. In these regions, we compared time trends in incidence of invasive breast cancer with the rest of Denmark. Since the number of clinical mammograms was relatively low, it was reasonable to assume that the breast cancer incidence outside the three screening regions represented the incidence of a population with low-intensity opportunistic screening. In Copenhagen and Fyn, a prevalence peak in incidence was seen during the first invitation round. During the subsequent invitation rounds, the incidence dropped to a level in line with the incidence expected without screening. The pattern was different in the small municipality of Frederiksberg, where the sensitivity was low during the first invitation round. Inclusion of screen-detected ductal carcinoma in situ cases did not change these results. The experiences from Copenhagen and Fyn show that organised mammography screening can operate without overdiagnosis of breast cancer.

Randomized comparison of enoxaparin, a low-molecular-weight heparin, with unfractionated heparin adjunctive to recombinant tissue plasminogen activator thrombolysis and aspirin: second trial of Heparin and Aspirin Reperfusion Therapy (HART II)

BACKGROUND

Adjunctive unfractionated heparin (UFH) during thrombolytic therapy for acute myocardial infarction (AMI) promotes the speed and magnitude of coronary artery recanalization and reduces reocclusion. Low-molecular-weight heparins offer practical and potential pharmacological advantages over UFH in multiple applications but have not been systematically studied as adjuncts to fibrinolysis in AMI.

METHODS AND RESULTS

Four hundred patients undergoing reperfusion therapy with an accelerated recombinant tissue plasminogen activator regimen and aspirin for AMI were randomly assigned to receive adjunctive therapy for at least 3 days with either enoxaparin or UFH. The study was designed to show noninferiority of enoxaparin versus UFH with regard to infarct-related artery patency. Ninety minutes after starting therapy, patency rates (thrombolysis in myocardial infarction [TIMI] flow grade 2 or 3) were 80.1% and 75.1% in the enoxaparin and UFH groups, respectively. Reocclusion at 5 to 7 days from TIMI grade 2 or 3 to TIMI 0 or 1 flow and TIMI grade 3 to TIMI 0 or 1 flow, respectively, occurred in 5.9% and 3.1% of the enoxaparin group versus 9.8% and 9.1% in the UFH group. Adverse events occurred with similar frequency in both treatment groups.

CONCLUSIONS

Enoxaparin was at least as effective as UFH as an adjunct to thrombolysis, with a trend toward higher recanalization rates and less reocclusion at 5 to 7 days.

New method for the selective capture of antibodies under physiological conditions

Hydrophobic charge induction chromatography is a recently developed method for protein separation based on the use of dual-mode ligands. They are designed in such a way so as to combine a molecular interaction supported by a mild hydrophobic association effect in the absence of salts. When environmental pH is changed, the ligand becomes ionically charged resulting into the desorption of the protein. This method is applied to the separation of antibodies from ascite fluids and culture supernatants from hybridomas cultured in the presence of fetal bovine serum or in protein free environment. Typically adsorption from cell culture supernatants is accomplished without any pH or ionic strength adjustment; the column is then washed with a typical buffer to eliminate protein impurities. Antibodies are then desorbed using acetate buffer, pH 4. Antibody binding capacity is in the range of 30 mg per ml of resin at 10% breakthrough. Antibody purity varies according to the initial feed stock and can reach values higher than 90% in a single pass. One example of antibody purification process involving hydrophobic charge induction chromatography as a capture step followed by a polishing phase with DEAE Ceramic HyperD is described. Longevity and ligand leakage are compatible with large-scale applications.

Pyrogenic reactions associated with single daily dosing of intravenous gentamicin

OBJECTIVE

To identify risk factors associated with an unexpected outbreak of pyrogenic reactions (PR) following intravenous gentamicin.

DESIGN

We conducted two cohort studies. PRs were defined as chills, rigors, or shaking within 3 hours after initiating the gentamicin infusion during the preepidemic (December 1, 1997-January 15, 1998) or epidemic (May 1-June 15, 1998) periods. We tested gentamicin vials for endotoxin using the limulus amebocyte lysate assay.

SETTING

Inpatient services of a large community hospital in Los Angeles, California.

RESULTS

During the epidemic period, 22 (15%) of 152 patients developed documented PRs following intravenous gentamicin. PRs were more likely among patients receiving single daily dosing (SDD) than multiple daily dosing gentamicin (20/73 [27%] vs. 2/79 [3%]; relative risk, 10.8; 95% confidence interval, 2.6 44.7). Laboratory analysis of gentamicin vials found endotoxin levels that were higher among Fujisawa-brand gentamicin (implicated brand) than gentamicin used after the outbreak terminated (non-implicated brand). Although endotoxin levels in the vials did not exceed US Pharmacopeia limits (1.7 endotoxin units/mg gentamicin), the use of SDD gentamicin may place patients at greater risk of receiving doses of endotoxin above the threshold for PRs in humans.

CONCLUSIONS

Reassessment of the acceptable amounts of endotoxin in gentamicin and other parenteral products should be considered when dosing intervals used in clinical practice change.

Effects of fluoride on rat vertebral body biomechanical competence and bone mass

For more than 30 years, sodium fluoride has been a commonly used therapeutic agent for established osteoporosis because of its repeatedly documented anabolic effect on trabecular bone mass. Recent clinical and experimental studies have, however, indicated a possible detrimental effect of fluoride on bone strength. Thus, the efficacy of fluoride therapy remains a controversial issue. The aim of this study was to investigate the effect of fluoride on both vertebral bone mass and quality in rats. Twenty-nine 3-month-old, female rats were randomized into three groups. One group served as a control group, and the other two groups received fluoridated water at different doses (100 ppm and 150 ppm). The rats were followed for 90 days. Three lumbar vertebrae were obtained from each rat, and changes in bone fluoride content, bone mass and biomechanical competence were assessed. The results revealed a significant increase in bone fluoride content, ash density and trabecular bone volume after fluoride treatment. Directly obtained load values and load corrected for cross-sectional area were constant. Load corrected for ash content, which is a measure of bone quality, decreased significantly after fluoride therapy. It is concluded that the increase in bone mass during fluoride treatment does not translate into an improved bone strength and that the bone quality declines. This investigation thereby supports the hypothesis of a possible negative effect of fluoride on bone quality.

[Initial otologic manifestation of Wegener's granulomatosis]

In most patients the first symptoms of Wegener's granulomatosis (WG) originates in the ENT-area. As a consequence, their prompt recognition allows diagnosis of the disease in an early stage. The beginning of WG with initial symptoms of otalgia followed by a rapidly progressive course is reported in a case. Prognosis in WG currently depends on making an early diagnosis and is improved by well-timed and sufficient therapy.

Environmental medicine: its introduction into a medical school primary care requirement

One hundred and twelve medical students participating in a required 6-week primary-care rotation completed a pretest of environmental medicine knowledge and attitudes at the start of the rotation and a similar posttest on the last day of the rotation. Control group students were to participate in the usual weekly didactic sessions of the clerkship. Intervention students were given a booklet describing environmental considerations in clinical medicine and introducing them to the concept of risk assessment, three computer-assisted instruction cases, and a problem-based learning (PBL) exercise involving role-play. Because voluntary compliance with evaluation forms was poor during year one, during the second year students in the intervention group were required to return evaluation forms in order to sit for the course final examination. Knowledge and attitudes of both intervention and control groups were compared at baseline and at the end of the rotation. Students in the intervention group also completed process evaluations of the intervention materials. Students in both intervention and control groups increased knowledge gains significantly during the second year of the intervention, while neither group improved during year 1. This may have been due to a 'spill-over' effect among primary-care teachers implementing the intervention. Students ranked both environmental and occupational medicine of least importance in their training compared with eight other aspects of medicine, and this ranking did not improve with intervention. The PBL exercise was well received by the students. Of 28 evaluations, 27 ranked the session in the highest 3 of a 5-part Likert scale for worthwhile content, and 24 would recommend the session to a friend.(ABSTRACT TRUNCATED AT 250 WORDS)

A research-based reconsideration of the psychoanalytic theory of dreaming

We present a brief review of sleep research which, when combined with psychoanalytic experience, has led to the hypothesis that REM sleep and dreaming serve the function of adaptation by the process of integration of information. We then report the results of a study of dreams, based on this hypothesis. We studied dreams and their relation to waking mental activity and found a correlation between problems in manifest dreams and those in pre- and postsleep waking life. Dreams can be understood on the basis of problems that appear in them. We also found evidence for a relation between the solution of problems in dreams and the fate of those problems the next day. We discuss these findings in relation to some of the controversies about dreaming, and then present suggestions for future research.

Use of a computer simulation to evaluate a seminar on child abuse

A computerized patient simulation was used to evaluate the effectiveness of a seminar on child abuse in changing students' behavior in assessing the problem and developing a treatment plan. The CAMPS system (DACIS Software) was selected because it allows students freedom to follow any pathway in selecting over 500 items of history, physical examination, laboratory, and treatments. In interacting with this simulation, students demonstrated how they integrate their knowledge into a clinical setting. The three-hour seminar covered the topics of physical and sexual abuse, patient neglect, and utilization of community resources for treatment. The control (n = 43) and experimental (n = 38) groups, enrolled in an introductory course in pediatrics, were given references to read about child abuse as part of the core curriculum, but they may or may not have had exposure to patients in their clinical work. Only the experimental group attended the seminar. As part of the course evaluation program, both groups interacted with eight computer simulations, two of which involved cases of child abuse. In the classic case of child abuse, the control and experimental groups had similar results. In the more difficult diagnostic problem (shaken baby), the groups differed significantly in total score, cost of the evaluation, and percentage of correct diagnosis.

Late thrombolytic therapy preserves left ventricular function in patients with collateralized total coronary occlusion: primary end point findings of the Second Mount Sinai-New York University Reperfusion Trial

The change in left ventricular ejection fraction from preintervention to predischarge was prospectively assessed in 393 patients with acute myocardial infarction. Within 12 h of symptom onset (mean 6.3 +/- 2.7 h), patients were randomly assigned to a double-blind intracoronary infusion of streptokinase, nitroglycerin, both streptokinase and nitroglycerin or conventional therapy without acute cardiac catheterization. Treatment effects were also assessed in prospectively defined angiographic subsets. There was a significant interaction between streptokinase and nitroglycerin (p less than 0.01), resulting in an increase in ejection fraction of 3.9 percentage units in the combined treatment arm (p less than 0.001). Patients with collateral flow to a totally obstructed infarct-related artery showed a significant improvement over those without collateral flow in the streptokinase (5.4 +/- 2.5%) and streptokinase-nitroglycerin (10.6 +/- 2.7%) arms, but not in the nitroglycerin arm. Time to treatment did not influence the change in ejection fraction. In patients with initial subtotal occlusion, thrombolytic therapy was of no short-term benefit because ejection fraction increased by 6% in all three intervention arms. These findings indicate that relatively late thrombolytic therapy results in significant myocardial salvage in those patients with collateralized total coronary occlusion. This benefit is potentiated by concomitant nitroglycerin therapy.

[Manifestations and therapy of malignant fibrous histiocytomas of the head and neck]

From 1982 through 1987, ten patients with malignant fibrous histiocytomas (MFH) in the head and neck area were treated at the ORL Department of the Central Hospital of Bremen. The primary tumor was situated in the region of the paranasal sinuses in six cases and in the parotid gland, the thyroid gland, the inferior maxilla, and the petrosal bone in one case, each. Nine patients were submitted to primary surgery. A postoperative irradiation was performed in four cases, and in four further cases this was done only when a recurrent tumor had been demonstrated. Three patients received a combined chemotherapeutical treatment. Eight patients died, the median survival time was 15 months. Besides local recurrences which occurred frequently, remote metastases are the decisive factor for the further evolution of the disease. The lung was the most common site of metastatic spread. Only two patients with MFH of the paranasal sinuses are living now without recurrence after an observation time of 24 and 36 months, respectively.

Documentation of students' clinical reasoning using a computer simulation

Computer simulations can provide both a clinical experience for teaching problem solving and a method of documenting a student's clinical reasoning style. The CAMPS simulation consists of approximately 500 items describing a patient's history, physical examination and laboratory results, and treatments. The student has full option to select any item in any order, producing a wide variation of performances. Since all of the students interact with the same clinical problems, the faculty member can make comparisons of that individual student with the class. From the record of the simulation encounter, the person responsible for student evaluations can prepare a narrative that lists the overall performance, the specific omissions and commissions, and comparisons with the class. Experience with a group of 111 students in a basic pediatric course showed that this method of documenting clinical inquiry detected a variety of levels of performances. Comparisons of the results of these tests with the faculty observations showed that 16% of these students who were judged to be very good or excellent in problem solving by the faculty performed at least 1 SD below the class average on the simulations. This project highlights the power of computer simulations to provide documentation of student performance with the additional benefit of a cost of less than $1 per student.

What makes something psychoanalytic?

QUESTIONS about the "essence" or boundary of a subject matter are both useful and hazardous. These concerns can coalesce or divide, divert or focus, affirm or degrade. With the hazards in mind, I wish to identify the forms of activity specific to psychoanalysis and psychoanalysts apart from other disciplines and practitioners. Given the variety of practices and the competing and complimentary theories, psychoanalysts have grown uncertain and defensive about the special domain of their inquiry. What makes something psychoanalytic?

A prospective randomized comparison of epirubicin and doxorubicin in patients with advanced breast cancer

Fifty-four patients with advanced breast cancer who had failed prior non-anthracycline combination chemotherapy were randomized to treatment with either epirubicin 85 mg/m2 or doxorubicin 60 mg/m2 intravenously every three weeks. Of 52 evaluable patients, 25% (six of 24) treated with epirubicin, and 25% (seven of 28) treated with doxorubicin experienced major therapeutic responses. The median duration of response to epirubicin was 11.9 months compared to 7.1 months with doxorubicin. Cardiotoxicity was monitored by serial multigated radionuclide cineangiocardiography performed at rest and after exercise. Laboratory evidence of cardiotoxicity was defined as a decrease in resting left ventricular ejection fraction of greater than 10% from the baseline value, or a decrease of 5% or greater with exercise compared with the resting study performed on the same day. Fifteen patients treated with epirubicin and 18 patients treated with doxorubicin had at least two determinations of left ventricular ejection fraction and were evaluable for laboratory cardiotoxicity. Using methods of survival analysis, the median doses to the development of laboratory cardiotoxicity were estimated to be 935 mg/m2 of epirubicin and 468 mg/m2 of doxorubicin. Four patients treated with epirubicin and five treated with doxorubicin developed symptomatic congestive heart failure. The median cumulative dose at which congestive heart failure occurred was 1,134 mg/m2 of epirubicin compared with 492 mg/m2 of doxorubicin. Fewer episodes of nausea and vomiting were observed in patients receiving epirubicin. Epirubicin is a new anthracycline with reduced cardiac toxicity, but preserved efficacy in the treatment of patients with advanced breast cancer.

Quantitative analysis of liver function in percutaneous transhepatic biliary drainage patients

The diagnostic usefulness of Tc-99m DISIDA cholescintigraphy as a predictor of eventual catheter and hepatic function in patients who have undergone percutaneous transhepatic biliary drainage (PTBD) for extrahepatic biliary obstruction was evaluated. Twenty-nine cholescintigrams were performed in 14 patients. The examinations were divided into two groups: Group A (N = 17), in which the patient's clinical status deteriorated within two to three days post-PTBD, and Group B (N = 12), in which the patients did well clinically post-PTBD. No significant difference between the two groups was demonstrated by visual analysis of the analog images or by analysis of serum bilirubin levels. A computer program, developed by the authors, quantitates several parameters of DISIDA kinetics, reflecting hepatic function based upon compartmental analysis. A significant difference (P less than .001) was demonstrated between the mean transport constants (blood clearance constant = k1; hepatic clearance constant = k2) for the two groups. It is concluded that serum bilirubin levels and visual inspection of analog images are inadequate independent predictors of hepatic function in patients post PTBD. The transport constants k1 and k2 are quantitative parameters of hepatic function that may be of prognostic value in patients post PTBD.

Internalization of colloidal gold-labelled insulin complexes into cultivated human smooth muscle cells

The binding and internalization of colloidal gold-labelled insulin complexes into cultivated human arterial smooth muscle cells was studied. We could demonstrate that the colloidal gold-labelled insulin complex was bound to specific receptors on the cell surface of smooth muscle cells and internalized after 30 min at 20 degrees C. The gold-labelled insulin complexes entered the cell via vesicles and escaped from them in the cytoplasm. The biological activity of the complexes was determined by measuring their effect on DNA synthesis in smooth muscle cells and incorporation of (14C)-glucose into isolated fat cells. The binding characteristics of the complexes were examined by competitive inhibition of 125I-insulin binding to isolated fat cells in the presence of increasing concentrations of gold-labelled insulin complexes or unlabelled insulin. The gold-labelled insulin complex showed a growth promoting and metabolic effect and was able to compete with 125I-insulin for its binding sites.

Large surface proteins of hepatitis B virus containing the pre-s sequence

The sequence of hepatitis B virus DNA contains an open reading frame which codes for a not-yet-identified protein of at least 389 amino acids. Only the products starting at the third (GP33/GP36) or the fourth (P24/GP27) initiation signal have been characterized as components of the viral surface antigen. We found a larger protein, P39, and its glycosylated form, GP42, in hepatitis B virus particles and viral surface antigen filaments. Immunological cross-reactions showed that P39/GP42 is partially homologous to P24/GP27 and GP33/GP36. The unique portion of its sequence bound monoclonal antibodies which had been induced by immunization with hepatitis B virus particles. Proteolytic cleavage patterns and subtype-specific size differences suggested that the sequence of P39 starts with the first initiation signal of the open reading frame. Its amino-terminal part (pre-s coded) is exposed at the viral surface and, probably, is highly immunogenic. A model is presented of how the open reading frame for the viral envelope leads to defined amounts of three different proteins.