A novel direct inducible nongenetic murine model of diabetes-aggravated atherosclerosis

Background and aims

Atherosclerosis, the main pathology underlying cardiovascular diseases is accelerated in diabetic patients (1,2). Genetic mouse models require breeding efforts which are time-consuming and costly. Our aim was to establish a new nongenetic model of inducible metabolic risk factors that mimics hyperlipidemia, hyperglycemia, or both and allows the detection of phenotypic differences dependent on the metabolic stressor(s) on any genetic background.

Methods and results

Wild type mice were injected with gain-of-function PCSK9D377Y (proprotein convertase subtilisin/kexin type 9) mutant adeno-associated viral particles (AAV) and streptozotocin (STZ) and fed either a high-fat diet (HFD) or high-cholesterol/high fat-diet (Paigen diet, PD) for 12 and 20 weeks. LDLR KO mice were used as reference control. Combined hyperlipidemic and hyperglycemic mice (HGHCi), but not hyperlipidemia (HCi) alone, displayed characteristic features of aggravated atherosclerosis characterized by larger and less stable plaques (necrotic core area in HGHCi HFD: 24% vs HCi HFD: 13% vs LDLR KO HFD: 18% area, at 20 weeks p<0.05; fibrous cap thickness in HGHCi: 13 μm vs HCi HFD: 23 μm vs LDLR KO HFD: 17 μm, at 20 weeks, p<0.05) which contained more macrophages (MOMA-2 in HGHCi HFD: 27% vs HCi HFD: 19% vs LDLR KO HFD: 46% area/plaque, at 20 weeks, p<0.05) and less smooth muscle cells (α-SMA in HGHCi HFD: 12% vs HCi HFD: 25% vs LDLR KO HFD: 18% area/plaque, at 20 weeks, p<0.05), on both HFD or PD diet. Diabetic atherosclerotic mice (HGHCi) fed a HFD showed 37% plaque area (of total lumen) compared to 16% plaque area in non-diabetic mice (HCi HFD) and 17% in LDLR KO HFD after 12 weeks; and 43% (HGHCi HFD) vs. 29% (HCi HFD) vs 39% plaque area (LDLR KO HFD) after 20 weeks (Figure 1A, B). Differences between the diabetic HGHCi and non-diabetic HCi HFD mice were confirmed using RNA-seq analysis of aortic tissue, revealing that significantly more genes were dysregulated in mice with combined hyperlipidemia and hyperglycemia than in the hyperlipidemia-only group. The HGHCi-associated genes were related to pathways regulating inflammation (increased Cd68, iNos, and Tnfa expression) and extracellular matrix degradation (Adamts4 and Mmp14) (Figure 1C). When comparing HFD with PD, the PD aggravated atherosclerosis to a greater extent in mice and showed plaque formation after 8 weeks (HGHCi PD: 48% plaque area vs. HCi PD: 30% plaque area), therefore, representing a direct inducible hyperglycemic atherosclerosis model compared with HFD-fed mice, in which atherosclerosis is severe by 8 weeks.

Conclusion

We established a nongenetic direct inducible mouse model of diabetes-aggravated atherosclerosis allowing comparative analyses of atherosclerosis in diabetic and non-diabetic conditions and its modification by diet, allowing analyses of multiple metabolic hits in mice.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Deutsche Forschungsgemeinschaft (DFG)

[Alcohol as a Means for the Prevention of Disturbances in Surgical Intensive Care Medicine]

Surgical treatment of patients with alcohol use disorder can lead to disturbances (withdrawal syndrome, delirium) which require intensive care treatment. In a surgical ward, the diagnosis of an alcohol related disorder is not always simple. Oftentimes patients conceal or trivialize the issue and as a result are admitted to the hospital in a non-abstinent or unstable state. It is risky to assume that patients with alcohol use disorder will successfully be supplied with alcohol in general hospitals. The risk can be reduced through presurgical identification and alcohol withdrawal of such patients. A literature review concludes that there is no secured evidence for the application of alcohol as prophylaxis or therapy of alcohol withdrawal syndrome in a surgical intensive care unit. The use of intravenous and oral alcohol in intensive care is an unnecessary risk to patients. There are more secure alternatives.

High Performance Liquid Chromatographic Determination of Carbohydrates in Chocolate: Collaborative Study

A collaborative study determining sucrose, glucose, fructose, maltose, and lactose in chocolate products was conducted using a previously published high performance liquid chromatographic (HPLC) method. Five samples (2 milk chocolates, 1 dark chocolate, 1 powdered mix, and 1 sirup) were analyzed in duplicate by 7 collaborators. The results indicate adequate method precision. In addition, the HPLC method allows for the simultaneous determination of 5 saccharides in chocolate products in 15 min. The method has been adopted as official first action.

Chemical-vapor deposited ultra-fast diamond detectors for temporal measurements of ion bunches

This article reports on the development of thin diamond detectors and their characterization for their application in temporal profile measurements of subnanosecond ion bunches. Two types of diamonds were used: a 20 μm thin polycrystalline chemical vapor deposited (CVD) diamond and a membrane with a thickness of (5 ± 1) μm etched out of a single crystal (sc) CVD diamond. The combination of a small detector electrode and an impedance matched signal outlet leads to excellent time response properties with a signal pulse resolution (FWHM) of τ = (113 ± 11) ps. Such a fast diamond detector is a perfect device for the time of flight measurements of MeV ions with bunch durations in the subnanosecond regime. The scCVD diamond membrane detector was successfully implemented within the framework of the laser ion generation handling and transport project, in which ion beams are accelerated via a laser-driven source and shaped with conventional accelerator technology. The detector was used to measure subnanosecond proton bunches with an intensity of 10⁸ protons per bunch.

Temperature measurement of hohlraum radiation for energy loss experiments in indirectly laser heated carbon plasma

For ion energy loss measurements in plasmas with near solid densities, an indirect laser heating scheme for carbon foils has been developed at GSI Helmholtzzentrum für Schwerionenforschung GmbH (Darmstadt, Germany). To achieve an electron density of 10^{22}cm^{3} and an electron temperature of 10-30eV, two carbon foils with an areal density of 100μg/cm^{2} heated in a double-hohlraum configuration have been chosen. In this paper we present the results of temperature measurements of both primary and secondary hohlraums for two different hohlraum designs. They were heated by the PHELIX laser with a wavelength of 527nm and an energy of 150J in 1.5ns. For this purpose the temperature has been investigated by an x-ray streak camera with a transmission grating as the dispersive element.

Interferometric phase detection at x-ray energies via Fano resonance control

Modern x-ray light sources promise access to structure and dynamics of matter in largely unexplored spectral regions. However, the desired information is encoded in the light intensity and phase, whereas detectors register only the intensity. This phase problem is ubiquitous in crystallography and imaging and impedes the exploration of quantum effects at x-ray energies. Here, we demonstrate phase-sensitive measurements characterizing the quantum state of a nuclear two-level system at hard x-ray energies. The nuclei are initially prepared in a superposition state. Subsequently, the relative phase of this superposition is interferometrically reconstructed from the emitted x rays. Our results form a first step towards x-ray quantum state tomography and provide new avenues for structure determination and precision metrology via x-ray Fano interference.

Probing the complex ion structure in liquid carbon at 100 GPa

We present the first direct experimental test of the complex ion structure in liquid carbon at pressures around 100 GPa, using spectrally resolved x-ray scattering from shock-compressed graphite samples. Our results confirm the structure predicted by ab initio quantum simulations and demonstrate the importance of chemical bonds at extreme conditions similar to those found in the interiors of giant planets. The evidence presented here thus provides a firmer ground for modeling the evolution and current structure of carbon-bearing icy giants like Neptune, Uranus, and a number of extrasolar planets.

Energy loss and charge transfer of argon in a laser-generated carbon plasma

This Letter reports on the measurement of the energy loss and the projectile charge states of argon ions at an energy of 4  MeV/u penetrating a fully ionized carbon plasma. The plasma of n(e)≈10(20)  cm(-3) and T(e)≈180  eV is created by two laser beams at λ(Las)=532  nm incident from opposite sides on a thin carbon foil. The resulting plasma is spatially homogenous and allows us to record precise experimental data. The data show an increase of a factor of 2 in the stopping power which is in very good agreement with a specifically developed Monte Carlo code, that allows the calculation of the heavy ion beam's charge state distribution and its energy loss in the plasma.

Coupling of high-intensity laser light to fast electrons in cone-guided fast ignition

Cu wires attached to Al cones are used to investigate the energy coupling efficiency of laser light to fast electrons through a cone into a dense plasma. We present experimental and simulation results demonstrating the effect on the energy coupling of effectively placing the cone in a surrounding high density plasma as well as the effect of a large preformed plasma inside the cone. Thick cone walls, simulating plasma surrounding the cone in fast ignition, reduce the energy coupling by a factor of up to 4. An increase in prepulse inside the cone by a factor of 50 further reduces coupling by a factor of 3. Simulations with the pic code lsp that include the laser plasma interaction and the preformed plasma from the flash code show that electron refluxing in thin cone-wall targets enhances coupling to the wire. The implications for full-scale cone-guided fast ignition are discussed.

Development of a Nomarski-type multi-frame interferometer as a time and space resolving diagnostics for the free electron density of laser-generated plasma

This article reports on the development and set-up of a Nomarski-type multi-frame interferometer as a time and space resolving diagnostics of the free electron density in laser-generated plasma. The interferometer allows the recording of a series of 4 images within 6 ns of a single laser-plasma interaction. For the setup presented here, the minimal accessible free electron density is 5 × 10(18) cm(-3), the maximal one is 2 × 10(20) cm(-3). Furthermore, it provides a resolution of the electron density in space of 50 μm and in time of 0.5 ns for one image with a customizable magnification in space for each of the 4 images. The electron density was evaluated from the interferograms using an Abel inversion algorithm. The functionality of the system was proven during first experiments and the experimental results are presented and discussed. A ray tracing procedure was realized to verify the interferometry pictures taken. In particular, the experimental results are compared to simulations and show excellent agreement, providing a conclusive picture of the evolution of the electron density distribution.

Time- and spectrally resolved measurements of laser-driven hohlraum radiation

At the GSI Helmholtz center for heavy-ion research combined experiments with heavy ions and laser-produced plasmas are investigated. As a preparation to utilize indirectly heated targets, where a converter hohlraum provides thermal radiation to create a more homogeneous plasma, this converter target has to be characterized. In this paper the latest results of these measurements are presented. Small spherical cavities with diameters between 600 and 750 μm were heated with laser energies up to 30 J at 532-nm wavelength. Radiation temperatures could be determined by time-resolved as well as time-integrated diagnostics, and maximum values of up to 35 eV were achieved.

Energy loss of argon in a laser-generated carbon plasma

The experimental data presented in this paper address the energy loss determination for argon at 4 MeV/u projectile energy in laser-generated carbon plasma covering a huge parameter range in density and temperature. Furthermore, a consistent theoretical description of the projectile charge state evolution via a Monte Carlo code is combined with an improved version of the CasP code that allows us to calculate the contributions to the stopping power of bound and free electrons for each projectile charge state. This approach gets rid of any effective charge description of the stopping power. Comparison of experimental data and theoretical results allows us to judge the influence of different plasma parameters.

MARS dialysis in decompensated alcoholic liver disease: a single-center experience

Acute decompensation of chronically stable alcoholic liver disease (ALD) is the most common cause of terminal liver failure in developed countries. Molecular adsorbent recirculation system (MARS) is increasingly used as artificial liver support to facilitate spontaneous organ recovery. However, the experience to date and the evidence to justify this therapeutic strategy in acutely decompensated ALD are still insufficient. We report our clinical experience with MARS in 14 patients with acutely decompensated ALD (6 male subjects; median age [interquartile range], 51 [47-56] years; Child-Pugh score, 12 [10-13]; Acute Physiology and Chronic Health Evaluation (APACHE) II score, 20 [18-24]) and severely impaired liver function whose disease was unresponsive to conventional supportive care. At least 3 sessions were applied in any patient (48 sessions in total). Under MARS treatment, the following levels decreased: bilirubin (544 [489-604] to 242 [178-348] micromol/L; P<0.001), creatinine (212 [112-385] to 91 [66-210] micromol/L; P=0.002), cholestatic parameter gamma-glutamyl transpeptidase (5.9 [1.8-13.1] to 4.6 [1.8-8.3] micromol/L) (P<0.001), blood urea nitrogen (56 [32-91] to 34 [21-68] mmol/L; P=0.044), and platelet count (176 [85-241] to 84 [31-145] Gpt/L; P=0.004). In contrast, MARS failed to improve daily urine output (P=0.846), ammonia levels (P=0.340), or thromboplastin time (P=0.775). Only 3 patients survived the hospital stay (mortality 78.6%). Although MARS improved laboratory parameters of hepatic detoxification and renal function in patients with acutely decompensated ALD, the patients' mortality remained unsatisfactorily high. Our experience does not support the indiscriminative use of MARS in acutely decompensated ALD without further controlled studies.

Acute reversible cardiomyopathy with cardiogenic shock in a patient with Addisonian crisis: a case report

A 42 year-old female, admitted to the ICU, with Addisonian crisis developed acute cardiopulmonary failure after hydrocortisone therapy was initiated. An echocardiogram showed severe reduction in the left-ventricular ejection fraction. Additionally, profound ECG abnormalities with diffuse ST-elevation and decreased QRS-amplitudes occurred, whereas Troponin-I was only moderately increased. Chest X-ray displayed bilateral pulmonary edema. The patient's condition culminated in respiratory failure and cardiogenic shock requiring catecholamines and ventilatory support. After a week, she had recovered uneventfully.

A multicenter, randomized, double-blind, placebo-controlled, dose-finding trial of a long-acting formulation of octreotide in promoting weight loss in obese adults with insulin hypersecretion

OBJECTIVE

To compare changes in weight in obese patients who received long-acting octreotide (octreotide LAR) at one of three dose levels (20, 40, or 60 mg) or placebo over 6 months and to identify the lowest dose of octreotide LAR that safely achieved optimal weight loss.

DESIGN

Randomized, double-blind, placebo-controlled trial of octreotide LAR at three dose levels.

PATIENTS

A total of 172 adults (28 men and 144 women) with at least moderate obesity (body mass index (BMI) range 30-65 kg/m2) and evidence of insulin hypersecretion were enrolled. Patients were predominantly either Caucasian (50.0%) or African American (45.3%). The mean age (38 +/- 11 year), weight (110.7 +/- 23 kg), and BMI (39.8 +/- 6.5 kg/m2) were similar across the four treatment groups.

MEASUREMENTS

Efficacy measures included weight, BMI, fasting serum glucose; triglycerides; percentage of total body fat and abdominal fat as measured by dual-energy X-ray absorptiometry; skin fold thickness; waist-to-hip circumference; leptin; percentage of carbohydrates, fat, and protein ingested; nutritional evaluation (including dietary analysis--3-day food record); quality of life (QoL; using the Impact of Weight on Quality of Life-Lite); Beck Depression Inventory; and Carbohydrate Craving Questionnaire. Safety measures included medical history, vital signs, physical examinations, hematology, blood chemistries, thyroid function tests, hemoglobin A1c, gallbladder ultrasound, electrocardiograms, and adverse events.

RESULTS

After 6 months of treatment, patients receiving 40 or 60 mg of octreotide LAR experienced statistically significant weight loss compared to baseline, with mean differences from placebo in percent weight change of -1.98 and -1.87%, respectively. This finding was accompanied by statistically significant mean decreases in BMI compared to baseline, that is, a mean decrease of 0.73 and 0.79 kg/m2 for the 40 and 60 mg treatment arms, respectively. The observed weight loss was progressive during the 6-month treatment in the two higher dose groups. The lowest dose to reach statistical significance in weight loss after 6 months' treatment was 40 mg. Post hoc analysis revealed a 3.5-3.8% weight loss at month 6 in the two higher dose groups among Caucasian patients having insulin secretion greater than the median of the cohort, defined as CIR(gp) (corrected insulin response at the glucose peak) > or = 1.43. There were no statistically significant changes in QoL scores, body fat, leptin concentration, Beck Depression Inventory, or macronutrient intake. Mean changes of blood glucose AUC(0-180 min) during an oral glucose tolerance test in patients taking octreotide LAR were 39-40 mg/dl h higher than those on placebo. A total of 7-21% of the patients taking octreotide LAR reached a 5% or greater decrease in body weight from Baseline, compared to 11% for the placebo group. This was not statistically significant. The most common adverse events included diarrhea, headache, cholelithiasis, nausea, and abdominal pain.

CONCLUSION

Octreotide LAR given at 40 or 60 mg resulted in statistically significant weight loss. A post hoc analysis stratifying patients by race and CIR(gp) indicated that Caucasian patients with the greater degree of insulin hypersecretion appeared to derive the most benefit from treatment. The observed safety profile was consistent with the known effects of octreotide from previous studies.

Formation and stability of high-spin alkali clusters

Helium nanodroplet isolation has been applied to agglomerate alkali clusters at temperatures of 380 mK. The very weak binding to the surface of the droplets allows a selection of only weakly bound, high-spin states. Here we show that larger clusters of alkali atoms in high-spin states can be formed. The lack of strong bonds from pairing electrons makes these systems nonmetallic, van der Waals-like complexes of metal atoms. We find that sodium and potassium readily form such clusters containing up to 25 atoms. In contrast, this process is suppressed for rubidium and cesium. Apparently, for these heavy alkalis, larger high-spin aggregates are not stable and depolarize spontaneously upon cluster formation.

Glycoproteins E and I of Marek's disease virus serotype 1 are essential for virus growth in cultured cells

The role of glycoprotein E (gE) and gI of Marek's disease virus serotype 1 (MDV-1) for growth in cultured cells was investigated. MDV-1 mutants lacking either gE (20DeltagE), gI (20DeltagI), or both gE and gI (20DeltagEI) were constructed by recE/T-mediated mutagenesis of a recently established infectious bacterial artificial chromosome (BAC) clone of MDV-1 (D. Schumacher, B. K. Tischer, W. Fuchs, and N. Osterrieder, J. Virol. 74:11088-11098, 2000). Deletion of either gE or gI, which form a complex in MDV-1-infected cells, resulted in the production of virus progeny that were unable to spread from cell to cell in either chicken embryo fibroblasts or quail muscle cells. This was reflected by the absence of virus plaques and the detection of only single infected cells after transfection, even after coseeding of transfected cells with uninfected cells. In contrast, growth of rescuant viruses, in which the deleted glycoprotein genes were reinserted by homologous recombination, was indistinguishable from that of parental BAC20 virus. In addition, the 20DeltagE mutant virus was able to spread from cell to cell when cotransfected into chicken embryo fibroblasts with an expression plasmid encoding MDV-1 gE, and the 20DeltagI mutant virus exhibited cell-to-cell spread capability after cotransfection with a gI expression plasmid. The 20DeltagEI mutant virus, however, was not able to spread in the presence of either a gE or gI expression plasmid, and only single infected cells were detected by indirect immunofluorescence. The results reported here demonstrate for the first time that both gE and gI are absolutely essential for cell-to-cell spread of a member of the Alphaherpesvirinae.

The selection of a commercial route for the D1 antagonist Sch-39166

D1 Antagonists have been reported to be potentially useful in a number of therapeutic areas. Sch-39166 is an example of such a selective D1 antagonist. Three different routes based on (1S,2S)-1-phenyl-1,3-propanediol (19), (+)-L-homophenylalanine (27) or trans-(+)-(1R,2R)-2-hydroxy-1-(methylamino)-1,2,3,4-tetrahydronaphthalene (37) were developed for the commercial preparation of Sch-39166. After analyzing each route for the best combination of cost, yield, throughput and efficiency, the synthesis of Sch-39166 starting from 37, which involves the opening of an aziridinium, was selected for optimization into the commercial route.

Interferometric pump-probe study of intense field excitation of sapphire

Under intense optical excitation, the polarizability of transparent optical materials has a significant third order, nonlinear contribution. This manifests itself in a wide variety of effects, which, under certain conditions, are collectively referred to as white light continuum generation. We report on a new approach that isolates, for the first time, some of these effects.

Chronic inborn erythrocytosis leads to cardiac dysfunction and premature death in mice overexpressing erythropoietin

The most common cause of an increase of the hematocrit is secondary to elevated erythropoietin levels. Erythrocytosis is assumed to cause higher blood viscosity that could put the cardiovascular system at hemodynamic and rheological risks. Secondary erythrocytosis results from tissue hypoxia, and one can hardly define what cardiovascular consequences are caused by chronic erythrocytosis or hypoxia. Herein, a novel transgenic (tg) mouse line is characterized that is erythrocytotic because of chronic overexpression of the human erythropoietin gene. These mice grow up well, reaching a hematocrit of about 0.80 in adulthood. Blood volume of adult tg mice was markedly increased by 75%. Unexpectedly, blood pressure was not elevated and cardiac output was not decreased. Still, the adult tg mice showed features of cardiac dysfunction with increased heart weight. In vivo, high-frequency echocardiography revealed marked ventricular dilatation that was confirmed by histologic examination. Furthermore, by transmission electron microscopy, a prominent intracellular edema of the cardiomyocytes was seen. Exercise performance of the tg mice was dramatically reduced, unmasking the severity of their compromised cardiovascular function. In addition, life expectancy of the tg mice was significantly reduced to 7.4 months. Our findings suggest that severe erythrocytosis per se results in cardiac dysfunction and markedly reduced life span.

Reconstitution of Marek's disease virus serotype 1 (MDV-1) from DNA cloned as a bacterial artificial chromosome and characterization of a glycoprotein B-negative MDV-1 mutant

The complete genome of Marek's disease virus serotype 1 (MDV-1) strain 584Ap80C was cloned in Escherichia coli as a bacterial artificial chromosome (BAC). BAC vector sequences were introduced into the U(S)2 locus of the MDV-1 genome by homologous recombination. Viral DNA containing the BAC vector was used to transform Escherichia coli strain DH10B, and several colonies harboring the complete MDV-1 genome as an F plasmid (MDV-1 BACs) were identified. DNA from various MDV-1 BACs was transfected into chicken embryo fibroblasts, and from 3 days after transfection, infectious MDV-1 was obtained. Growth of MDV-1 recovered from BACs was indistinguishable from that of the parental virus, as assessed by plaque formation and determination of growth curves. In one of the MDV-1 BAC clones, sequences encoding glycoprotein B (gB) were deleted by one-step mutagenesis using a linear DNA fragment amplified by PCR. Mutant MDV-1 recovered after transfection of BAC DNA that harbored a 2.0-kbp deletion of the 2.6-kbp gB gene were able to grow and induce MDV-1-specific plaques only on cells providing MDV-1 gB in trans. The gB-negative virus reported here represents the first MDV-1 mutant with a deletion of an essential gene and demonstrates the power and usefulness of BACs to analyze genes and gene products in slowly growing and strictly cell-associated herpesviruses.

Valvular abnormalities and cardiovascular status following exposure to dexfenfluramine or phentermine/fenfluramine

CONTEXT

Fenfluramine and dexfenfluramine were voluntarily withdrawn from the market in September 1997 because of reports of an association with heart valve abnormalities. Studies have been limited by lack of comparison with untreated controls.

OBJECTIVE

To evaluate cardiovascular status and the prevalence of valvular abnormalities, as assessed by clinical cardiovascular parameters and echocardiography, in patients treated for obesity with dexfenfluramine or phentermine/fenfluramine.

DESIGN

Reader-blinded controlled study completed in February 1998.

SETTING AND PARTICIPANTS

Twenty-five clinical centers in the United States. Of 1640 enrolled subjects, 1473 were eligible (479 and 455 had taken dexfenfluramine and phentermine/fenfluramine, respectively, continuously for 30 days or more in the previous 14 months, and 539 were untreated matched controls) and provided clinical and echocardiographic data. Mean (SD) age was 47.4 (11.4) years, mean body mass index was 35.0 (7.4) kg/m2, and 74% were women. Mean (SD) duration of therapy was 6.0 (3.3) months (range, 1-18.4 months) in the dexfenfluramine group, and 11.9 (10.4) months (range, 1.4-63 months) in the phentermine/fenfluramine group, while the untreated group had no anorexigen use during the previous 5 years.

MAIN OUTCOME MEASURES

Cardiovascular signs and symptoms; echocardiographic evidence of aortic (AR) or mitral (MR) regurgitation according to US Food and Drug Administration (FDA) criteria (AR > or = mild or MR > or = moderate) and by grade; tricuspid and pulmonic valve regurgitation; and aortic, mitral, and tricuspid valve leaflet mobility and thickness, for treated vs untreated subjects.

RESULTS

Cardiovascular signs and symptoms were similar among anorexigen-treated and untreated subjects. Prevalence rates and relative risk (RR) of AR were significantly increased in anorexigen-treated patients and were 8.9% in the dexfenfluramine group (RR, 2.18; 95% confidence interval [CI], 1.32-3.59), 13.7% in the phentermine/fenfluramine group (RR, 3.34; 95% CI, 2.09-5.35), and 4.1% in the untreated group (P<.001). No statistically significant differences in prevalence were observed for MR, thickening or decreased mobility of any valve leaflet, calculated pulmonary artery systolic pressure, or left ventricular ejection fraction. Serious cardiac events (including myocardial infarction, congestive heart failure, or ventricular arrhythmia) occurring at any time were not statistically different in treated and untreated subjects (dexfenfluramine, 9.0%; phentermine/fenfluramine, 4.0%; and untreated, 8.4%); and following anorexigen treatment were uncommon (dexfenfluramine, 2.3%; phentermine/fenfluramine, 2.4%, and untreated, 3.3%, when adjusted for the median start date of anorexigen use).

CONCLUSIONS

Our data indicate that use of dexfenfluramine and phentermine/fenfluramine is associated with an increase in the prevalence of AR using FDA echocardiographic criteria, but was not associated with an increase in the prevalence of MR using FDA criteria or with serious cardiac events.

Initial weight loss as a predictor of response to obesity drugs

BACKGROUND

Initial weight loss has been used as a predictor of long-term response to obesity drugs. Discontinuation of drugs has been recommended if weight loss is not > or =1.81 kg (4 lb) in the first month of treatment.

OBJECTIVE

We compared the weight loss response at 6 months of patients losing > or =1.81 kg (responders) vs. < 1.81 kg (non-responders) in the first month of treatment with the combination of fenfluramine and phentermine.

DESIGN

Outcomes at 6 months in 975 patients treated in a comprehensive program of phentermine (15-30 mg/d) d,l-fenfluramine (20-60 mg/d), were compared for responders vs. non-responders.

RESULTS

In the total population, first month weight loss highly correlated with % reduction in body mass index (BMI) after 6 months of treatment (P<0.001). The reduction in baseline BMI after 6 months treatment was greater for the responders (15.9% vs. 10%, P<0.02). However, the North American Association for the Study of Obesity (NAASO) guidelines for drug treatment of obesity state that a 5% weight loss produces significant health benefits, and may be used as a criteria for success. At 6 months, 76%, 37% and 14% of the non-respondents had lost > or = 5%, > or = 10% and > or = 15% of baseline BMI, respectively. After 6 months treatment the reductions in serum cholesterol, triglycerides and LDL-cholesterol were 0.55, 0.31 and 0.42 mmol/L, respectively, (P< or =0.006), for the non-responders. Adverse effects after 6 months of treatment and the dropout rates after 1 y of treatment were not significantly different for the two groups.

CONCLUSIONS

Although, the first month weight loss predicted the long-term response to phen-fen treatment, it was inadequate in identifying the non-responders and may unnecessarily preclude potential beneficiaries of the treatment.

Ultrastructural localization of alpha-3 integrin subunit in malignant melanoma and adjacent epidermis

Eight cases of malignant melanoma were studied by immunohistopathology and immunoelectron microscopy. Alpha3 integrin localization was documented in malignant melanoma cells, basal and suprabasal keratinocytes, melanocytes, blood vessels and in basement membrane material. In melanoma cell membranes and, to a lesser extent, the interior of melanosomal vesicles were labeled. In addition, neighbouring cells such as basal and suprabasal keratinocytes and melanocytes showed strong alpha3-integrin expression. The labeling was much stronger in the plasma membrane than in the cytoplasm. Endothelial cells showed stronger labeling of the cytoplasm than of the plasma membrane. In some cases we found increased flocculent material surrounding melanoma cells or nests that seems to contain basement membrane protein components, specifically alpha3-integrin subunits. Compared to normal epidermis alpha3-labeling was stronger in tissues of malignant melanoma.

Long-term drug treatment of obesity in a private practice setting

This study evaluated the long-term efficacy and safety of the combination of phentermine and fenfluramine for the treatment of obesity in a private practice setting. A total of 1388 consecutive, qualified patients presenting to a private general internal medicine practice in Charlotte, NC, were enrolled with eligibility criteria including: age 18 years to 60 years, 20% over "desirable" bodyweight or body mass index > 27, no serious medical or psychiatric disease, and no contraindications to drug therapy. Patients were instructed in diet, exercise, and behavior modification techniques and received phentermine (15 mg/day to 30 mg/day) and fenfluramine (20 mg/day to 60 mg/day) continuously for over 3 years. Average duration of treatment was 15.9 months, and average weight loss at the last visit was 11.6 kg, or 11.7% of initial bodyweight. For patients completing 1 year of drug treatment, mean weight loss was 16.5 kg, or 16% of initial weight. Weight loss persisted for 2 years, but partial regain was seen at 3 years. The dropout rates were 18% at 6 months, 39% at 1 year, 68% at 2 years, and 78% at 3 years. At 1 year, blood pressure of hypertensive patients fell from 151/95 mm Hg to 127/78 mm Hg, and serum cholesterol and triglycerides of hyperlipidemic patient fell by 0.750 mmol/L (29 mg/dL) and 0.937 mmol/L (83 mg/dL), respectively. Adverse events were modest. We conclude that, in a private practice setting, long-term treatment of obesity with the combination of phentermine, fenfluramine, and a weight maintenance program is generally safe and effective. More research is needed to determine efficacy and safety for longer than 3 years.

Long-Term Pharmacologic Treatment of Morbid Obesity in a Community Practice

OBJECTIVE

To determine the safety, efficacy, and metabolic changes in patients with morbid obesity treated with d,l-fenfluramine and phentermine in an open-label trial.

METHODS

In patients with a body mass index (BMI) =40.0 kg/m 2 (N = 298) who sought assistance at a private medical practice for treatment of obesity, 60 mg of d,l-fenfluramine and 15 to 30 mg of phentermine resin were administered daily in an open-label trial, without placebo controls, for up to 24 months. The setting was a community-based private practice. Study subjects were given instructions for a 1,200 to 1,400 kcal/day diet, exercise, and behavior modification. Follow-up included a monthly medical visit, behavior modification group attendance, quarterly laboratory evaluation, and electrocardiographic monitoring.

RESULTS

BMI decreased from 45.8 kg/m2 to 37.4 kg/m2 (P<0.0001) in those who completed 12 months of treatment and to 38.2 kg/m2 (P<0.0001) in those who continued the protocol for 24 months. Statistically significant decreases in fasting blood glucose, total and high-density lipoprotein cholesterol, triglycerides, systolic and diastolic blood pressures, and fasting insulin concentrations were noted. The dropout rate was 42.3% at 12 months and 69.8% at 24 months. The most common reason given for discontinuing participation in the study was "success" with the program (mean BMI loss of 7.8 kg/m2). Five patients discontinued treatment because of side effects. No laboratory or electrocardiographic abnormalities were noted that could be attributed to the medications. No statistically significant regain of weight occurred in those who completed 12 or 24 months of treatment.

CONCLUSION

In this study, treatment of morbid obesity with d,l-fenfluramine and phentermine was safe and efficacious in promoting and maintaining weight loss. Moreover, statistically significant changes were noted in metabolic variables associated with risk of heart disease. Future efforts must focus on methods to improve long-term compliance.

[Degradation of Maillard reaction products by amylolytic enzymes. 3. Inhibition of glucoamylase, alpha-amylase and alpha-glucosidase by heat treated alpha-glucans and melanoidins]

Amylolytic enzymes are only slightly inhibited by thermal treated alpha-glucans (10-15%). The addition of glycine to the thermolysis mixture produces no increase of the inhibition. The inhibition of the enzyme activity is probably caused by short-chain alpha-glucans that the secondary binding places of the active centre coat and therefore the hydrolysis is reduced. Glucoamylase and alpha-amylase are not inhibited by non-dialysed melanoidines from the reaction of D-glucose and glycine, but there is a strong inhibition of alpha-glucosidase by these melanoidines (up to 45%). Strongly coloured, low molecular compounds that are formed during the Maillard-reaction and are soluble in ethyl acetate cause no inhibition of Glucoamylase and alpha-amylase.

[Degradation of Maillard reaction products by amylolytic enzymes. 2. Enzymatic degradation of heat-treated alpha-glucans with and without amino compounds]

The enzymatic degradation of thermal treated alpha-glucans with amylolytic enzymes depends on the reaction environment (T, pH, moisture), the degree of polymerisation (DP) and the branch of the substrates as well as on the presence of amino compounds. The chemical changes of the alpha-glucans due to thermolysis at 180 degrees C are characterized by means of the amount of reducing substances and the amount of maltooligosaccharides (HPLC). In general the enzymatic degradability of the thermal treated alpha-glucans is decreased with increasing time of thermolysis, temperature and moisture content. The enzyme activity with the thermal treated alpha-glucans is diminished in the same way. The addition of amino compounds reduces the enzymatic degradability only at the beginning of the reaction. With increasing time of thermolysis the thermolysates without glycine addition are hardly degraded. As reason for these differences in the enzymatic degradation transglycosylation and non-enzymatic browning reactions (caramalisation/Maillard-reaction) are assumed.

[The effect of Maillard reaction products on enzyme reactions]

In this article current knowledge about the Maillard reaction in vivo is described first, especially the glycosylation reactions of various tissues and the identification of different final products and intermediates of Maillard reaction. The influence of MRP on digestion is of significant importance. These products are absorbed in different ways and are excreted in various amounts. Hence, the organism is variably influenced by MRP. The influence of defined MRP, of glycosylated proteins and of melanoidins on glycosidases and proteases is described. The effects produced depend on the enzyme and on the used MRP. Reactive alpha-dicarbonyl compounds play an important role in the organism. Further possible reactions of these compounds caused by reductases are discussed. The protein structure of enzymes is changed by Maillard reaction. Thereby the enzyme activity is influenced by covalent modifications of different amino acids and by inter- and intramolecular crosslinking. Finally, the use of enzymes and monoclonal antibodies for detection of MRP is discussed.

In vivo diode dosimetry for total marrow irradiation

PURPOSE

To describe a method and evaluate the efficacy of using a p-type silicon diode as an alternative to thermoluminescent dosimeters for verifying the accuracy of total marrow irradiation setups and calculations.

METHODS AND MATERIALS

A calibration factor has been measured for a 6 MV photon beam incident horizontally onto a polystyrene phantom inside an in-house built total marrow irradiation stand. Signal responses due to positioning and orientation of the diode with respect to the source were compared to a 0.6 cc cylindrical ionization chamber inside a polystyrene phantom. Procedures for predicting the diode reading and taking entrance measurements have been developed and action levels established to determine causes for discrepancies when ratios between predicted and actual values fell outside a +/- 5% tolerance range. Measurements were taken at the skin surface over the umbilicus calculation point for alternating 1.5 Gy anterior and posterior fractions given bidaily over a 3-day period.

RESULTS

A total of 137 measurements taken from January to September 1994 for 23 patients were analyzed using a frequency histogram. The histogram indicated a mean reading of 1.002 +/- 2.6, and that three of the measurements fell outside the 5% tolerance. Investigation into the cause of the discrepancies showed that the diode had been improperly placed one time and that further patient immobilization needs to be considered.

CONCLUSION

It is possible to use a diode as an in vivo dosimeter for a total marrow irradiation technique. The ease of implementation and immediate readouts make a diode system preferable to a thermoluminescent system for identifying systematic errors and verifying treatment configurations and monitor unit calculations.

Combined drug treatment of obesity

Pharmacological treatment of obesity has been neglected as a viable therapeutic option for many years. Recent long term studies with combinations of obesity drugs gives promise that drugs may play a role in weight maintenance, which classically has been the most difficult aspect of treating obesity. Currently available obesity drugs include centrally acting adrenergic agents and serotonin agonists. Drugs still in development include a lipase inhibitor that produces fat malabsorption, a combined adrenergic-serotonergic reuptake inhibitor, various gut-central nervous system peptides, and a number of beta-3 agonists. Any of these obesity drugs given alone produces modest weight loss, and for most, weight loss continues for as long as medication is given. The most successful drug regimens to date are combinations of phentermine and fenfluramine or of ephedrine, caffeine, and/or aspirin. The former combination produces reduction in body weight and complications of obesity for 2 to almost 4 years in clinical trials to date. More research is needed to document long term efficacy and particularly the long term safety of these and other combinations.

The quality of routinely collected maternity data

OBJECTIVE

To assess the validity of clinical information held on a regional maternity database, the St Mary's Maternity Information System (SMMIS).

DESIGN

A retrospective review of 892 maternity case notes and matched SMMIS records, by a midwife trained in clinical coding techniques.

SETTING

Three maternity units in the North West Thames Region.

MAIN OUTCOME MEASURES

Percentage agreement for 17 directly recorded SMMIS data items and equivalent data abstracted from the notes. Frequencies of diagnosis codes abstracted from case notes, as compared with those generated by SMMIS on the basis of directly recorded data.

RESULTS

A generally high level of agreement was observed between the abstracts of the notes and the SMMIS records. Of the 17 data items examined, 10 showed 95% agreement or better, and all but two exceeded 80% agreement. Little difference was found between the levels of agreement observed at the three sites. A greater number and range of diagnosis codes were abstracted from the notes than were generated by SMMIS.

CONCLUSIONS

The directly recorded clinical data held on the SMMIS regional database is largely accurate and consistently recorded across a variety of units. The database can therefore be considered a valuable resource for the comparative audit of maternity practice. The SMMIS technique for deriving, on a semi-automatic basis, diagnosis codes from the directly recorded fields, appears to work moderately well. We suggest that the direct method of data collection used in SMMIS could provide a model for other specialties in the National Health Service.

[The decomposition of Maillard reaction products by amylolytic enzymes. 1. Reversible inhibition of alpha- and glucoamylase and alpha-glucosidase by oligosaccharide Amidori compounds]

The influence of Amadori-compounds (fructosyl-, maltulosyl- and maltotriulosylglycin) on the activity of the enzymes alpha-glucosidase (from Saccharomyces cerevisiae), glucoamylase (from Aspergillus niger) and alpha-amylase (from porcine pancreas) was studied. Fructosylglycin was not hydrolyzed by all three enzymes. alpha-Glucosidase hydrolyzes maltulosylglycin 10 times slower than maltotriulosylglycin. Glucoamylase and alpha-amylase catalyze only the cleavage of maltotriulosylglycin to form glucose and maltulosylglycin. The activities of alpha-glucosidase and glucoamylase are inhibited through the Amadori-compounds fructosyl- and maltulosylglycin. These Amadori-compounds don't influence the activity of alpha-amylase. Electronic effects or interactions between the secondary amino function of Amadori-compounds and the carboxyl- or carboxylate groups of active centres could be responsible for such an inhibition.

Comparative hospital databases: value for management and quality

OBJECTIVES

To establish an accurate and reliable comparative database of discharge abstracts and to appraise its value for assessments of quality of care.

DESIGN

Retrospective review of case notes by trained research abstractors and comparison with matched information as routinely collected by the hospitals' own information systems.

SETTING

Three district general hospitals and two major London teaching hospitals.

PATIENTS

The database included 3905 medical and surgical cases and 2082 obstetric cases from 1990 and 1991.

MAIN MEASURES

Accessibility of case notes; measures of reliability between reviewers and of validity of case note content; application of high level quality indicators.

RESULTS

The existing hospital systems extracted insufficient detail from case notes to conduct clinical comparative analyses for medical and surgical cases. The research abstractors at least doubled the diagnostic codes extracted. Interabstractor agreement of about 70% was obtained for primary diagnosis and assignment to diagnosis related group. These data were sufficient to create a comparative database and apply high level quality indicators designed to flag topics for further study. For obstetric-specific indicators the rates were comparable for abstractors and the hospital information systems, which in each case was a departmentally based system (SMMIS) producing more detailed and accessible data.

CONCLUSIONS

Current methods of extracting and coding diagnostic and procedural data from case notes in this sample of hospitals is unsatisfactory: notes were difficult to access and recording is unacceptably incomplete.

IMPLICATIONS

Improvements as piloted in this project, are readily available should the NHS, hospital managers, and clinicians see the value of these data in their clinical and managerial activities.