Effects of cigarette smoking or nicotine replacement on cardiovascular risk factors and parameters of haemorheology

OBJECTIVES

Cigarette smoking causes cardiovascular (CV) disease, but the relative roles of nicotine and other components of tobacco smoke remain unclear. We investigated the effect of stopping smoking, by using nicotine replacement therapy (NRT), on haemorheology parameters.

DESIGN

Open, parallel-group trial (intervention group and control smokers).

SETTING

Clinic within university department of pharmacology.

SUBJECTS

One hundred and ninety-seven males, aged 25-45 years, smoking >20 cigarettes per day.

INTERVENTIONS

One hundred and sixty-four subjects were instructed to stop smoking and received NRT for 12 weeks and 33 acted as controls. After 12 weeks, NRT was discontinued, and all subjects were followed-up at 26 weeks. At the end of the study, the NRT group was divided into abstainers (self-reported, verified by exhaled carbon monoxide <10 ppm) and relapsers, who were unable to remain abstinent.

MAIN OUTCOME MEASURES

Plasma viscosity, fibrinogen, erythrocyte deformability, reactive capillary blood flow, transcutaneous partial oxygen tension (tcpO2) and haematocrit, assessed at 4, 8, 12, and 26 weeks. Results. After 6 months, plasma fibrinogen (9.95 vs. 8.24 micromol x L(-1) at baseline; P < 0.003), reactive capillary flow (t-pmax: 9.3 vs. 11.2 s at baseline; P < 0.005), and tcpO2 (50.4 vs. 34.9 mmHg at baseline; P < 0.0001) were significantly improved in abstainers, but changes in plasma viscosity and erythrocyte deformability were inconclusive. Other CV risk factors, such as haematocrit and white blood cell count, decreased to a greater extent in abstainers than in relapsers. Expired carbon monoxide concentrations reflected the changes in smoking and decreased in abstainers from 30.4 ppm at baseline to 4.2 ppm; P < 0.0001). Conclusions. Smoking cessation improved CV parameters, and use of nicotine medications did not negate these improvements.

Development of a molecular diagnosis assay based on electrohybridization at plastic electrodes and subsequent PCR

Technologies enabling specific recognition of medically relevant nucleic acid sequences will play a pivotal role in future medical diagnosis. Whereas many approaches to molecular diagnosis systems include DNA microarrays on chips and fluorometric detection, the basis of our approach is the use of inexpensive components like plastic or metal thin film electrodes with low multiplexing and an electrochemical detection unit. To increase the sensitivity, PCR can be used as an intermediate step. For selective enrichment, specific nucleic acid probes were covalently attached at their 5'-ends to conducting polycarbonate/carbon fiber electrodes. Complementary oligonucleotides were enriched at the electrodes by cyclic inversion of an electrochemical potential, transferred into a PCR vial and thermally or electrochemically desorbed. The analysis of the PCR product shows the efficiency and selectivity of the electrochemical enrichment. Hybridization of DNA was shown by electrochemical methods, in this work especially by differential pulse voltammetry (DPV) using the single strand specific hybridization redox indicator osmium(VIII)-tetroxide, and potentiometric stripping analysis (PSA). This combination of experimental methods is the basis for a molecular diagnosis system including a disposable nucleic acid modified working electrode for specific enrichment, detection and quantification, and an optional capillary PCR module for fast amplification.

Biodecontamination of animal rooms and heat-sensitive equipment with vaporized hydrogen peroxide

Common methods used to decontaminate and disinfect laboratory animal areas are difficult to standardize, labor-intensive, and potentially hazardous for staff members and the environment. As an alternative to traditional methods, we tested fumigation with vaporized hydrogen peroxide by using the VHP 1000 Biodecontamination System. The design of our air-conditioning system allowed the connection of the generator to any animal room by using the ventilation piping, thus forming a closed circuit. A 3-h cycle consisting of dehumidification, conditioning, sterilization, and aeration was developed and shown to be effective. The biodecontamination process was monitored during five independent trials using chemical and biological (Bacillus stearothermophilus spores) indicators. Contact plates for testing surfaces and room air for environmental bacteria, yeasts, and fungi consistently showed fewer than 10 colony-forming units per 100 cm2 or per 1 liter air. In addition, this method proved successful with heat-sensitive equipment like the blower units of individually ventilated caging systems. Overall, the system was easy to use and very effective in biodecontaminating animal rooms and equipment in a reproducible manner. There were no signs of corrosion or functional damage after more than 10 fumigation cycles. Work load and potential health risk for staff members and the environment was negligible.

Long-term weight loss with sibutramine: a randomized controlled trial

CONTEXT

Treatment of obesity requires long-term therapy, which can be hampered by difficulties in achieving patient compliance. The effectiveness of sibutramine hydrochloride in treating obesity has been shown in randomized controlled trials.

OBJECTIVE

To compare the effectiveness of 2 distinct sibutramine regimens with each other and with placebo for weight reduction among obese persons.

DESIGN

Randomized, double-blind, parallel-group placebo-controlled trial from April 1997 to September 1998.

SETTING

One hundred eight private practices and 3 outpatient departments of university hospitals in Germany.

PATIENTS

A total of 1102 obese adults (body mass index, 30-40 kg/m(2)) entered the 4-week open-label run-in period with 15 mg/d of sibutramine, 1001 of whom had weight loss of at least 2% or 2 kg were randomized into the 44-week randomized treatment period.

INTERVENTIONS

Patients were randomly assigned to receive 15 mg/d of sibutramine continuously throughout weeks 1-48 (n = 405); 15 mg/d of sibutramine intermittently during weeks 1-12, 19-30, and 37-48, with placebo during all other weeks (n = 395); or placebo for weeks 5-48 (n = 201).

MAIN OUTCOME MEASURE

Weight loss during the randomized treatment period, compared among all 3 groups.

RESULTS

Mean weight loss in the intention-to-treat population during the 44-week randomized treatment period was 3.8 kg (4.0%) in patients receiving continuous therapy (95% confidence interval [CI], - 4.42 to - 3.20 kg) and was 3.3 kg (3.5%) in patients receiving intermittent therapy (95% CI, - 3.96 to - 2.66 kg), vs a mean weight gain of 0.2 kg (0.2%) (95% CI, - 0.60 to 0.94 kg) in patients receiving placebo. Therapeutic equivalence of the 2 active treatments could be shown. Although there was a greater weight loss in the continuous than in the intermittent group, this difference was nonsignificant (P =.28) and the 95% CIs were within the predefined range of therapeutic equivalence-0 +/-1.5 kg (-1.37 to 0.28 for the intent-to-treat population). Overall weight loss during the 48-week period was 7.9 kg and 7.8 kg in the continuous and intermittent groups, respectively, but was 3.8 kg in the sibutramine run-in placebo group. Waist circumference reduction, triglyceride levels, and high-density lipoprotein cholesterol concentrations were also positively influenced by sibutramine treatment. Systolic and diastolic blood pressures were stable across all 3 groups. Overall, adverse events occurred at similar frequencies across all treatment groups, but the proportion was lowest in the group receiving intermittent therapy.

CONCLUSIONS

Sibutramine, administered for 48 weeks to a typically obese population, results in clinically relevant weight loss compared with placebo. Regarding effectiveness, continuous and intermittent sibutramine therapies are equivalent and the safety profiles for both treatments are comparable.

The social organization of fish shoals: a test of the predictive power of laboratory experiments for the field

By contrast with a multitude of laboratory studies on the social organization of fish, relatively little is know about the size, composition and dynamics of free-ranging fish shoals. We give an overview of the available information on fish shoals and assess to what degree the predictions made from laboratory studies are consistent with field data. The section on shoal choice behaviour in the laboratory is structured so that the evidence for different shoaling preferences is discussed in the context of their mechanisms and functions. Predictions based on experiments in captivity regarding preferences for conspecifics, individuals of similar body length and unparasitized fish were highly consistent with field observations on free-ranging shoals whereas preferences for familiar conspecifics and kin remain to be conclusively demonstrated in the field. In general, there is a shortage of studies in which shoaling preferences have been investigated both in the laboratory and the field, and field studies have so far been largely descriptive revealing little about the underlying mechanisms of observed patterns. Given the great importance of fish shoals both in fundamental and applied research, an advancement of our knowledge of their social organization should significantly contribute to a better understanding of a whole range of topics including reciprocal altruism, group-living and self-organization.

Fish shoal composition: mechanisms and constraints

Observations were made on three fish species (banded killifish (Fundulus diaphanus), golden shiner (Notemigonus crysoleucas) and white sucker (Catostomus commersoni)) in a temperate lake (New Brunswick, Canada) in order to investigate the relationship between shoal choice behaviour of individual fishes and shoal composition. Encounters between shoals were observed to take place every 1.1 min per shoal and an encounter lasted 3.7 s on average. The duration of shoal encounters was influenced by shoal size but not by differences between shoals in either body length or species. Conversely, the outcome of shoal encounters (i.e. ences between shoals in either body length or species. Conversely, the outcome of shoal encounters (i.e. whether or not an individual changes shoal) was influenced by body length and species differences but not by shoal size. Together, these results suggest that encounter duration itself is unlikely to have an important influence on encounter outcome. The collection of ten entire fish shoals showed that they were assorted by species and body length. A simulation model demonstrated that individual shoal choice behaviour alone could account for the generation and maintenance of the observed levels of size assortedness of shoals without invoking the existence of other sorting mechanisms such as differential swimming speeds. However, the generation of species assortedness was not predicted by the model. Furthermore, our data suggest that fish density acts as a constraint on shoal choice, influencing both shoal size and composition. This work has implications for studies on information transfer and reciprocal altruism within populations.

Attention deficit hyperactivity disorder: binding of [99mTc]TRODAT-1 to the dopamine transporter before and after methylphenidate treatment

Involvement of the dopaminergic system has been suggested in patients suffering from attention deficit hyperactivity disorder (ADHD) since the symptoms can be successfully treated with methylphenidate, a potent blocker of the dopamine transporter (DAT). This study reports the findings on the status of the DAT in adults with ADHD before and after commencement of treatment with methylphenidate, as measured using [99mTc]TRODAT-1. Seventeen patients (seven males, ten females, aged 21-64 years, mean 38 years) were examined before and after the initiation of methylphenidate treatment (3x5 mg/day). All subjects were injected with 800 MBq [99mTc]TRODAT-1 and imaged 3 h p.i. Single-photon emission tomography (SPET) scans were acquired using a triple-headed gamma camera. For semiquantitative evaluation of the DAT, transverse slices corrected for attenuation were used to calculate specific binding in the striatum, with the cerebellum used as background [(STR-BKG)/BKG]. Data were compared with an age-matched control group. It was found that untreated patients presented with a significantly increased specific binding of [99mTc]TRODAT-1 to the DAT as compared with normal controls [(STR-BKG)/BKG: 1.43+/-0.18 vs 1.22+/-0.06, P<0.001]. Under treatment with methylphenidate, specific binding decreased significantly in all patients [(STR-BKG)/BKG: 1.00+/-0.14, P<0.001]. Our findings suggest that the number of DAT binding sites is higher in drug-naive patients suffering from ADHD than in normal controls. The decrease in available DAT binding sites under treatment with methylphenidate correlates well with the improvement in clinical symptoms. The data of this study help to elucidate the complex dysregulation of the dopaminergic neurotransmitter system in patients suffering from ADHD and the effect of treatment with psychoactive drugs.

Spiral interpolation algorithm for multislice spiral CT--part I: theory

This paper presents the adaptive axial interpolator (AAI), a novel spiral interpolation approach for multislice spiral computed tomography (CT) implemented in a clinical multislice CT scanner, the SOMATOM Volume Zoom (Siemens Medical Systems, Forchheim, Germany). The method works on parallel-beam data generated from the acquired fan-beam data by azimuthal rebinning. Spiral interpolation is performed by distance-dependent weighting; i.e., for each ray, its distance to the image plane is evaluated and serves as an argument to a freely selectable weighting function, resulting in a weight factor. A normalization step is applied to the weight factors to ensure that the sum of all corresponding weights (i.e., the weights applied to rays that contribute to the same ray in the interpolated sinogram) is 1. By selection of appropriate weighting functions and suitable adjustment of the tube current, it is possible to keep the slice sensitivity profiles (SSP) as well as the pixel noise constant for all pitch values in the relevant range. Also, a large range of slice-thickness can be reconstructed from a given collimation. The method is, thus, very versatile. Further advantages are that it uses the entire applied dose for imaging and allows for efficient implementation using a table lookup approach.

Spiral interpolation algorithms for multislice spiral CT--part II: measurement and evaluation of slice sensitivity profiles and noise at a clinical multislice system

The recently introduced multislice data acquisition for computed tomography (CT) is based on multirow detector design, increased rotation speed, and advanced z-interpolation and z-filtering algorithms. We evaluated slice sensitivity profiles (SSPs) and noise of a clinical multislice spiral CT (MSCT) scanner with M = 4 simultaneously acquired slices and adaptive axial interpolator (AAI) reconstruction software. SSPs were measured with a small gold disk of 50 microm thickness and 2-mm diameter located at the center of rotation (COR) and 100 mm off center. The standard deviation of CT values within a 20-cm water phantom was used as a measure of image noise. With a detector slice collimation of S = 1.0 mm, we varied spiral pitch p from 0.25 to 2.0 in steps of 0.025. Nominal reconstructed slice thicknesses were 1.25, 1.5, and 2.0 mm. For all possible pitch values, we found the full-width at half maximum (FWHM) of the respective sensitivity profile at the COR equivalent to the selected nominal slice thickness. The profiles at 100 mm off center are broadened less than 7 % on the average compared with the FWHM at the COR. In addition, variation of the full-width at tenth maximum (FWTM) at the COR was below 10% for p < or = 1.75. Within this range, image noise varied less than 10% with respect to the mean noise level. The slight increase in measured slice-width above p = 1.75 for nominal slice-widths of 1.25 and 1.50 mm is accompanied by a decrease of noise according to the inverse square root relationship. The MSCT system that we scrutinized provides reconstructed slice-widths and image noise, which can be regarded as constant within a wide range of table speeds. With respect to this, MSCT is superior to single-slice spiral CT. These facts can be made use of when defining and optimizing clinical protocols: the spiral pitch can be selected almost freely, and scan protocols can follow the diagnostic requirements without technical restrictions. In summary, MSCT offers constant image quality while scan times are reduced drastically. Volume scans with three-dimensional (3-D) isotropic resolution are routinely feasible for complete anatomical regions.

Increased striatal dopamine transporter in adult patients with attention deficit hyperactivity disorder: effects of methylphenidate as measured by single photon emission computed tomography

Ten previously untreated adults with attention deficit hyperactivity disorder (ADHD) were investigated before and after 4 weeks of treatment with a dose of 3x5 mg methylphenidate/d by single photon emission computed tomography (SPECT) with [Tc-99m]TRODAT-1, the first Tc-99m labelled SPECT ligand specifically binding to the dopamine transporter (DAT). For semiquantitative evaluation of the DAT, specific binding ([STR-BKG]/BKG) was calculated in the striatum (STR) with the cerebellum used as background (BKG). The patients with ADHD presented with increased specific binding of Tc-99m-TRODAT-1 to the DAT as compared with age and sex matched controls ([STR-BKG]/BKG 1.43+/-0.18 vs. 1.22+/-0.05, P<0.001). After treatment with methylphenidate specific binding decreased in all patients ([STR-BKG]/BKG 1.02+/-0.23, P<0.001). Thus, for the first time it could be demonstrated using SPECT that methylphenidate lowers increased striatal DAT availability in adults suffering from ADHD.

Dendritic organization of neurons of the superior colliculus in animals with different visual capability

The aim of the study was to compare several morphological characteristics of neurons in the superficial layers of the superior colliculus in diurnal and nocturnal mammals with different visual specialization. Thus, we investigated the rat (Rattus norvegicus), a nocturnal animal; the tree shrew (Tupaia glis), a diurnal animal, and the Mongolian rodents, Microtus brandti (nocturnal) and Alticola barakshin (diurnal). The investigation was focused on the study of the organization and extent of dendrites of Golgi-impregnated projection neurons, which were divided in two classes: narrow-field and wide-field cells. We determined that the ratios between the volumes of dendritic fields of the investigated neuronal types and the total volume of the superior colliculus differed to a great extent between the different species. The tree shrew had the largest superior colliculus and the smallest wide-field neurons, while the rat had the largest wide-field neurons. As for the Mongolian rodents, we provided the first description of superior colliculus neurons. The day-active animal Alticola barakshin was found to have a 50% larger volume of the superior colliculus than that of the night-active animal Microtus brandti, and the size of the dendritic field of both wide-field neurons and narrow-field neurons was smaller than that of Microtus brandti. Electron microscopic investigation of wide-field neurons performed in the rat revealed only a few symmetric synaptic contacts on the arborizations of distal and terminal dendrites and numerous asymmetric synapses on the dendritic stem. Our findings support the hypothesis that whereas the narrow-field neurons are relay neurons in the retino-tecto-thalamic pathway of the visual system, the wide-field neurons may play additional roles in the retino-tecto-reticulo-spinal system.

The influence of nutritional state on shoal choice in zebrafish, Danio rerio

We investigated the mechanisms and functions of shoal choice in relation to nutritional state in the zebrafish. Single fish that had been well fed or food deprived for 2 days were presented with a choice between two stimulus shoals. Food-deprived test fish showed a significant preference for well-fed stimulus fish over food-deprived ones whereas well-fed test fish did not exhibit any significant preference. Subsequent experiments showed that food-deprived test fish had a significantly higher foraging success in shoals consisting of well-fed individuals than in ones that comprised food-deprived fish. No difference in the locomotory behaviour of food-deprived and well-fed stimulus fish was found with respect to the proportion of time spent swimming (as opposed to being motionless), the proportion of time spent in the upper part of the test tank and the number of sharp turns. However, body weight, stomach width (measured directly behind the pectoral girdle) and ventro-dorsal height significantly decreased over a 48-h food-deprivation period. The potential use of the latter factors for the recognition of food-deprived individuals is discussed. Copyright 1999 The Association for the Study of Animal Behaviour.

Controlling charge states of large ions

The charge state of ions produced in electrospray ionization (ESI) was reduced in a controlled manner to yield predominantly singly charged species by exposure of the aerosol to a bipolar ionizing gas. Analysis of the resulting ions on an orthogonal time-of-flight mass spectrometer yielded mass spectra greatly simplified compared with conventional ESI spectra. The decreased spectral complexity afforded by the charge reduction facilitates the analysis of mixtures by ESI mass spectrometry.

Photographic standards in plastic surgery

Standard photographic technique in plastic surgery is an important topic that has been stressed in the discipline over the past several years. Clinical photographs should always be taken with the same camera lens, lens setting, lighting, film, and patient position to ensure reproducibility and to enable valid pre- and postoperative comparisons. A 35-mm single lens reflex camera is highly recommended for this type of photography. Two lenses are suggested, one with a focal length range of 50 to 60 mm and one with a focal length range of 90 to 105 mm. Both should have macro capability. Two or more flash units are recommended, either camera-mounted or a studio system set-up in the office. Using the patient preparation method and technique outlined in the text, the Standards in Clinical Photography achieve consistency from patient to patient and also in the same patient in pre- and postoperative photographs. Henceforth, the information discussed in the article forms the basis for standard views, regardless of the image-capture medium.

[Hyperkinetic syndrome (attention deficit-/hyperactivity disorder) in adulthood]

The clinical picture of adult hyperkinetic syndrome (HKS) or attention deficit/hyperactivity disorder is nearly unknown in Germany. It can be estimated, that approximately one third of affected children also show symptoms as adults. In the combined type of the syndrome symptoms of inattention as well as of hyperactivity and impulsivity are present, a predominantly inattentive or hyperactive-impulsive type is possible. Retrospective diagnosis of HKS in childhood can be difficult. Disorganization, emotional disturbances and stress intolerance are common in adults with HKS as well as residual symptoms of learning disorders like dyslexia, dyscalculia and dysgraphia. In differential diagnosis especially affective, anxiety and antisocial personality disorders have to be considered, for which on the other side a frequent comorbidity with HKS is known. There is strong evidence for genetic transmission. Neurobiological findings revealed dysregulation of neurotransmitters. For treatment stimulants as pemoline and methamphetamin are effective, in addition tricyclic antidepressants or beta blockers; positive effects are probable for moclobemide, bupropion, fluoxetine and venlafaxine.

Astroglial distribution of neurokinin-2 receptor immunoreactivity in the rat spinal cord

Two mouse monoclonal antibodies, 11H9.1 and 1G7.10, raised against the COOH-terminus peptide (359-390) of the rat neurokinin-2 receptor, were used to visualize by light and electron microscope immunocytochemistry the distribution of this receptor in adult rat spinal cord. At all spinal levels, immunoreactivity was mainly observed in two narrow crescentic zones bordering the gray matter of the dorsal and ventral horns, and around the central canal. In the light microscope, this labelling was the densest within the outer part of lamina I facing the dorsal column, where it took the form of minute dots and streaks scattered in the neuropil. In the electron microscope, such a localization was exclusively astrocytic and essentially involved astrocytic leaflets, as indicated by the size and irregular shape of the immunostained processes, their location between and around neuronal profiles, and their occasional display of glial filaments. The diaminobenzidine reaction product showed some predilection for the plasma membrane and was occasionally seen at gap junctions of these labelled processes. Many labelled astrocytic leaflets were observed in the immediate vicinity of axon terminals containing large dense-cored vesicles, and around fibres morphologically identifiable as primary afferent, unmyelinated C-fibres. These observations suggest that astrocytic neurokinin-2 receptors could define the effective sphere of neurokinin A neuromodulation in rat spinal cord, via alterations in the regulation of the extracellular environment and glutamate uptake by astrocytes and/or the release of putative astroglial mediators. The astrocyte neurokinin-2 receptors, activated by extrasynaptic neurokinin A, might thus co-operate with neurokinin-1 and neurokinin-3 neuronal receptors in the modulation of nociceptive information.

[ACE-inhibitor-induced angioedema. The most frequent cause of oropharyngeal edema]

Angiotensin-converting enzyme (ACE) inhibitor-induced angioedema is supposed to be an uncommon cause for oropharyngeal edema. Between January 1, 1993 and February 1, 1997 we treated 20 patients with edema of the oropharyngeal region that was not caused by infection or irradiation. The most common reason was an ACE-inhibitor-induced angioedema and occurred in 9 cases, all of whom required inpatient treatment. The medical management consisted of the administration of intravenous (i.v.) glucocorticosteroids in all cases, H1-blockers in 6 cases, epinephrine by inhalation in one case and i.v. epinephrine in another case. Tracheostomy had to be performed in one patient. In our experience it is necessary to reconsider ACE inhibitor-induced angioedema in any case of an oropharyngeal edema. However, there is no reason for the routine application of epinephrine in these cases.

Effects of magnetic fluid hyperthermia (MFH) on C3H mammary carcinoma in vivo

Magnetic fluids (MF) have a potential for hyperthermia due to their good power absorption capabilities. Recent in vitro experiments with the so-called 'Magnetic Fluid Hyperthermia (MFH)' have shown that human tumours cells are homogeneously inactivated after AC magnetic field excitation of extracellular MF. The aim of the present study was the evaluation of a high dose MFH on intramuscularly implanted mammary carcinoma of the mouse. The tumours originated from initial in vivo passages of a spontaneous parent tumour. Because of larger variations of tumour growth in this rather primary model, logistic regression of non-averaged volumes was performed for each treatment modality. All growing tumours were randomized 30 days after transplantation (day of treatment) with an overall size distribution between 120-400 mm3. An intratumoural steady state temperature of 47 +/- 1.0 degrees C was maintained for 30 minutes with whole-body AC magnetic fields of 6-12.5 kA/m at 520 kHz. The magnetic fluid was #P6, which is a high biocompatible dextran magnetite. #P6 was given intratumourally (1.5 x 10(-2) mg ferrite/mm3) 20-30 minutes before excitation and was combined with magnetic targeting (50 mT), which yielded a 2.5-fold enhancement of the intratumoural iron concentration. Histological examinations of tumour tissue after intralesional ferrofluid administration alone indicated deep infiltration of the fluid into the carcinoma tissue, but no evidence of tissue damage as compared with untreated controls. In contrast, widespread tumour necrosis was observed after MFH. After application of either dextran or ferrofluid alone (no difference, p = 0.665), tumour growth was slightly delayed in comparison with untreated controls (p < 0.001). In contrast to the good fit of the controls (R = 0.92-0.87), tumour growth after MFH was much more heterogeneous; some tumours showed no evidence for regrowth at 50 days whereas others had grown quite readily. This most probably reflected the critical problem of homogeneity of the intratumoural MF distribution, which was also confirmed qualitatively by Magnetic Resonance Imaging (MRI), heterogeneous pigmentation of MFH treated tumours, and up to 1 degree C differences between temperature probes in the same tumour during AC magnetic field application. However, a quantitative comparison between intratumoural MF-heterogeneity and tumour response could not be performed in this study. Despite these current limitations, the regression analysis of the MFH data yielded a smaller tumour volume of about 1000 mm3 at 50 days growth time in contrast to all three controls. In conclusion, encouraging results have been obtained, which show, that one single high dose MFH is already able to induce local tumour control in many cases within 30 days after treatment. To overcome the uncertainties of intratumoural MF heterogeneity, advanced intralesional application methods are currently under development.

Tunable terahertz radiation from Stark wave packets

We investigate the possibility that Stark wave packets can be used as a source of shaped terahertz radiation. Calculations for the sodium atom reveal that the frequency and intensity of the THz emission can be controlled over a broad range by varying the parameters of the excitation pulse.

Introduction

When a coherent superposition of Rydberg states is excited by a laser pulse, a Rydberg wave packet is created. These wave packets are supremely quantum mechanical objects. However, they can be constructed to display classical, nearly classical, or semiclassical behavior, and thus serve as a natural bridge between the microscopic and mesoscopic worlds. In addition, their comparative simplicity allows detailed studies of the fundamental interactions of light with matter. The authors of this focus issue were invited to submit papers that reflect both the range of dynamical behavior exhibited by Rydberg wave packets, and the depth of understanding of them that is possible with current experiments and theory. In particular, the papers in this issue illustrate the possibility that emerging laser technology can be used not only to observe quantum behavior, but also to control it.

Profound and sustained inhibition of platelet aggregation by Fradafiban, a nonpeptide platelet glycoprotein IIb/IIIa antagonist, and its orally active prodrug, Lefradafiban, in men

BACKGROUND

Clinical trials have demonstrated that platelet glycoprotein (GP) IIb/IIIa antagonists effectively prevent acute thrombotic events. Orally active GP IIb/IIIa antagonists are essential to evaluate the clinical benefit of long-term treatment. We therefore investigated platelet inhibition by the GP IIb/IIIa antagonist Fradafiban (BIBU 52; Fradafiban is the recommended INN of BIBU 52) and its orally administered prodrug, Lefradafiban (BIBU 104; Lefradafiban is the recommended INN of BIBU 104) in healthy subjects.

METHODS AND RESULTS

The activity and plasma levels of Fradafiban and Lefradafiban were evaluated in double-blind, placebo-controlled studies in 130 healthy male subjects. One to 15 mg Fradafiban continuously infused over 30 minutes reversibly inhibited platelet aggregation in platelet-rich plasma ex vivo in response to 20 micromol/L ADP (5 mg, 100% inhibition at 27 minutes after administration) and to both 1.0 (5 mg, 100%) and 10 microg/mL (15 mg, 97+/-3%) collagen. Single oral doses of Lefradafiban inhibited ADP-induced aggregation by 59+/-14% (50 mg [mean+/-SD]; n=8), 90+/-12% (100 mg), and 99+/-2% (150 mg) 8 hours after administration. Correlations between activity and Fradafiban plasma levels were identical after Fradafiban and Lefradafiban treatment. After day 1, oral TID Lefradafiban treatment for 7 days inhibited aggregation by > or = 31+/-9.6% (25 mg TID; n=8), 53+/-12% (50 mg; n=7), and 88+/-6.6% (75 mg; n=8) just before the next dose. A similar correlation between the activity and Fradafiban plasma levels was observed at days 1, 2, and 7.

CONCLUSIONS

Oral administration of Lefradafiban maintains the potent platelet GP IIb/IIIa antagonism of Fradafiban during treatment of healthy subjects for 1 week without signs of loss of the antiplatelet activity.

Immunoelectron microscopic localization of NK-3 receptor in the rat spinal cord

The immunocytochemical localization of tachykinin NK-3 receptor (NK-3R) was studied in rat spinal cord using a mouse monoclonal antibody directed against the C-terminus peptide (434-465) of the human NK-3R. Light microscopic labeling prevailed in lamina II and lamina X. Under the electron microscope, the immunolabeling in lamina II involved mainly dendritic spines inside glomeruli, preterminal axons and axon terminals. This suggests that neurokinin B can modulate primary afferent, sensory information, both post- and pre-synaptically. These actions are likely to involve extrasynaptic diffusion of the peptide, since NK-3R immunoreactivity was not found in association with postjunctional differentiations.

Frequency of BCL-2/J(H) translocations in peripheral blood of follicular lymphoma patients

Polymerase chain reaction (PCR) assays have been developed for follicular lymphoma-associated BCL-2/J(H) translocations. Few data are available on the quantitation by PCR of these translocations in peripheral blood mononuclear cells (PBM) of follicular lymphoma (FL) patients. We report that only one of five studied FL patients had a high level of these translocations in the circulation, namely, about 35,000 translocations per 5 x 10(6) PBM. This patient was stable with an excellent performance status at the time of this assay; however, he died of leukemia 1 month later.

Factor V Leiden is not responsible for stroke in patients with sickling disorders and is uncommon in African Americans with sickle cell disease

Cerebrovascular accidents in patients with sickle cell anemia are among the most devastating complications of the disease. It has recently been demonstrated that some patients have a hypercoagulable state on the basis of the presence of an abnormal factor V molecule, factor V Leiden. We undertook this study to evaluate the presence of factor V Leiden in sickle cell patients with stroke. Eighty-two patients with either Hgb SS, Hgb SC, or Hgb S(beta+)-thalassemia comprised the study population. Of the 82 patients in the study, 19 of them had a history of stroke. In our study population, none of the stroke patients possessed the factor V Leiden mutation. One of the non-stroke patients was a heterozygote for the mutation (P = 1.00). The overall frequency of the factor V Leiden allele in our population is 0.6%. The estimated prevalence for this mutation is reportedly between 3 and 7% in Caucasian populations. We conclude that the gene frequency for factor V Leiden is less common in Africa Americans with sickle cell disease. Furthermore, factor V Leiden does not appear to be responsible for the development of stroke in sickle cell patients.

Studies on the selection of new matrices for ultraviolet matrix-assisted laser desorption/ionization time-of-flight mass spectrometry

A new group of compounds has been successfully tested as matrices for ultraviolet matrix-assisted laser desorption/ionization mass spectrometry (UV-MALDI MS). Several new matrices for UV-MALDI MS have been found by choosing, as potential matrices, compounds that perform an intramolecular proton transfer along an intramolecular H-bond under UV irradiation. Compounds of this type are, for example, salicylamide, salicylanilide, several ortho-hydroxyacetophenones and ortho-hydroxybenzophenones. The matrix activity of these compounds is compared to the corresponding meta- and para-isomers and to the matrix activity of such well known matrices as 2,5-dihydroxybenzoic acid and 2,4,6-trihydroxyacetophenone. It was found that meta- and para-substituted hydroxycarbonyl compounds show either a significantly lower or no matrix activity compared with the ortho isomers.

Studies on the selection of new matrices for ultraviolet matrix-assisted laser desorption/ionization time-of-flight mass spectrometry

A new group of compounds has been successfully tested as matrices for ultraviolet matrix-assisted laser desorption/ionization mass spectrometry (UV-MALDI MS). Several new matrices for UV-MALDI MS have been found by choosing, as potential matrices, compounds that perform an intramolecular proton transfer along an intramolecular H-bond under UV irradiation. Compounds of this type are, for example, salicylamide, salicylanilide, several ortho-hydroxyacetophenones and ortho-hydroxybenzophenones. The matrix activity of these compounds is compared to the corresponding meta- and para-isomers and to the matrix activity of such well known matrices as 2,5-dihydroxybenzoic acid and 2,4,6-trihydroxyacetophenone. It was found that meta- and para-substituted hydroxycarbonyl compounds show either a significantly lower or no matrix activity compared with the ortho isomers.

Asbestos-related diseases and asbestos types used in the former GDR

In the period from 1960 to 1990 about 1.4 million tonnes of asbestos were imported by the former German Democratic Republic (GDR) and mainly processed into asbestos-cement products for the building industry. The production was concentrated in the former counties of Magdeburg and Dresden. In the past, asbestos was primarily used as insulation and fire prevention material, etc. in the large-scale chemical industry. Chrysotile was predominantly imported from the former Soviet Union, partly from Canada. Very small amounts of amphiboles came from Mozambique, but they were not processed in the counties of Magdeburg and Halle. In the German Federal State of Saxony-Anhalt, approx. 600 asbestoses, almost 2,700 pleural changes caused by asbestos, 843 asbestos-induced mesotheliomas and 787 bronchial and laryngeal carcinomas caused by asbestos were recorded in the period from 1960 to 1990. A considerable percentage of the mesotheliomas are solely due to exposure to chrysotile asbestos.

[Evaluation of prognostic factors in preoperative therapy of endometrial carcinoma]

The authors evaluated in a group of 23 women with carcinoma of the endometrium the possibility of reliable assessment of prognostic factors and their part in the selection of a suitable surgical method. They used computed tomography for preoperative assessment of the extent of myometrial invasion which is considered from the prognostic aspect an important factor of first order. They also evaluated the contribution of CT to assessment of the state of regional lymph nodes and to assess the stage of the disease. They proved the reliability of CT in the assessment of myometrial invasion in 87% and a significant contribution to the assessment of the stage of the disease. Preoperative histological assessment of the subtype and grading of the endometrial carcinoma made it possible to differentiate patients with a low and high risk of development of a malignant neoplasm.

[Severe oropharyngeal angioedema caused by ACE inhibitor. A case report]

Inhibitors of angiotensin converting enzyme (ACE) are suspected of inducing angioedemas in up to 0.2% of all patients. These angioedemas are mainly localized in the upper airways and therefore can cause severe airway obstruction and even death due to suffocation. We report the case of a 64-year-old man, who underwent emergency tracheotomy because of severe angioedema of the larynx, which was refractory to pharmacological treatment. We conclude that patients with ACE inhibitor-induced angioedemas should be observed by monitoring in an intensive care unit to ensure the possibility of early intubation, because conventional antiallergic-antiedematous therapy by histamine-receptor antagonists and corticosteroids is an insufficient, unreliable form of therapy in severe cases. Especially otolaryngologists should know about this uncommon potentially life-threatening side-effect of ACE inhibitors.

Salivary duct carcinoma. Part I. A clinicopathologic evaluation and DNA image analysis of 13 cases with review of the literature

Salivary duct carcinoma is an uncommon and relatively unknown clinically aggressive adenocarcinoma of salivary origin that histologically demonstrates a remarkable resemblance to invasive carcinoma of the breast. We report the clinicopathologic features of 13 cases that were also examined by image analysis for DNA ploidy. The results were then analyzed collectively with the less than 100 cases of salivary duct carcinoma reported in the English-language literature to define the characteristics of this unusual neoplasm. The 12 men and one woman averaged 68 years of age (range, 49 to 90 years). All tumors arose in the parotid (10 cases) or submandibular glands (three cases). Nine tumors were aneuploid, three diploid, and one was indeterminate because of insufficient tissue. Follow-up (median, 24 months) was available in 12 cases: three patients died of disease, six were alive without disease, and three died of other causes. Combining our cases with those in the literature, a total of 104 cases, confirms that salivary duct carcinoma is a highly malignant neoplasm with distinctive clinical and pathologic features. It arises almost exclusively in the major salivary glands (96% of cases), is three times more common in men, and usually occurs in patients over 50 years of age (range, 22 to 91 years). One-third of patients experience local recurrences, 59% develop positive regional lymph nodes, 46% have systemic metastases (lungs and bones), and 65% die of their disease, usually within 4 years of diagnosis. Determination of tumor ploidy has no prognostic significance. The presence of distant metastasis was the only clinicopathologic feature that was statistically associated with prognosis (p = 0.02); all patients with systemic metastasis died of disease.

Salivary duct carcinoma. Part II. Immunohistochemical evaluation of 13 cases for estrogen and progesterone receptors, cathepsin D, and c-erbB-2 protein

Salivary duct carcinoma is an infrequent highly aggressive salivary gland tumor that is histologically similar to ductal carcinoma of the breast. We studied 13 cases by immunohistochemistry for the presence of estrogen and progesterone receptors, cathepsin D, and c-erbB-2 protein to determine whether the similarity to breast carcinoma extended beyond the light microscope to the molecular level and, if so, whether these markers might have therapeutic or prognostic value. Twelve of 13 cases contained sufficient amounts of tumor tissue for evaluation. Of these 12 cases, one (8%) was positive for estrogen receptors, none was positive for progesterone receptors, five (42%) were positive for cathepsin D, and three (25%) were positive for c-erbB-2 protein. Expression of cathepsin D and c-erbB-2 protein does not appear to have prognostic significance in salivary duct carcinoma. The 8% incidence of immunopositivity for estrogen receptors and absence of progesterone receptors in salivary duct carcinoma is considerably less than that seen in breast cancer. Nevertheless, because the occurrence of systemic metastasis in salivary duct carcinoma is such an ominous development largely unresponsive to chemotherapy, antihormonal therapy, such as used in breast cancer, might be considered on a trial basis for those tumors that are estrogen receptor-positive when conventional therapeutic modalities fail.

Use of asbestos, health risks and induced occupational diseases in the former East Germany

In the period from 1960 to 1990 about 1.4 million tons of asbestos were imported and mainly processed into asbestos-cement products for the building industry. The production was concentrated in the former countries of Magdeburg and Dresden. In the past asbestos was primarily used as insulation and fire prevention material, etc. in the large-scale chemical industry. The asbestos was imported from the former Soviet Union, smaller amounts came from Canada. In the German Federal State of Saxony-Anhalt, approximately 600 asbestoses, almost 2700 pleural changes caused by asbestos, 843 asbestos-induced mesotheliomas and 787 bronchial and laryngeal carcinomas were recorded in the period from 1960 to 1990. A considerable percentage of the mesotheliomas are solely due to exposure to chrysotile asbestos.

Differential fitness returns in relation to spatial position in groups

1. A general overview of position-related fitness differences in group-living animals is given for the first time. 2. Differential fitness returns in groups are often related to competition for resources among group members due to resource limitation. If resources are very scarce, then competition may finally lead to the disbandment of groups. The encounter-dilution effect predicts that grouping confers a benefit if the conspicuousness of large groups does not outweigh the dilution effect and each predator or parasite attacks only one (or a few) prey per encounter (Uetz & Hieber, 1993). While the encounter-dilution effect limits the number of predators and parasites a group is faced with at a given time, marginal predation and communal defence are probably the most important factors for position-related differences in predation risk. 3. Limitation of resources increases competition between groups members and should widen the gap between fitness returns of dominant and subordinate group members. In some group-living animals such as schooling fish, however, predator pressure has apparently selected for uniformity in morphology and behaviour which presumably restricts the potential for resource competition (Magurran & Seghers, 1991). 4. A general problem of assessing individual fitness returns in that different short-term strategies may achieve the same long term goals (Magurran, 1993). The use of feeding rates and predation risks as currencies for fitness returns over short time periods is therefore questionable and can only be a first step. So far, hardly any information is available on long-term effects of differences in positioning behaviour. 5. Food availability and food intake rates tend to be higher in edge positions, whereas energy expenditure does not differ significantly with group position in non-roosting mobile groups. This suggests that edge positions achieve a higher net-energy pay-off and should therefore be preferred by individuals with low energy reserves. 6. Differential predation risks are well documented for stationary and colony-breeding species, but there is a lack of data for mobile, non-breeding species. The reason for the latter is that predation is rarely observed (in the field) and often difficult to relate to group position in fast-moving species such as flocks of birds. Further studies, especially in the field, are needed. 7. Vigilance rates and attack rates do not necessarily give a true reflection of mortality risk. Vigilance is not exclusively related to predation and can be confounded by competition effects and hunger. Attack rates are difficult to translate into per capita risks if hardly any mortality is observed and therefore little information is available about the ratio of successful attacks/total attacks. 8. Most of the literature up to date consists of descriptive studies. There is a need for experimental work that investigate (a) the influence of predator attack mode on differential predation risks; (b) the influence of internal states (such as hunger) on the tradeoff between predation risk and foraging behaviour and its consequences for the positioning behaviour in groups; (c) the 'egalitarian' nature of groups with respect to group position. Do all individuals continuously rotate positions? Or do dominant individuals monopolize certain positions?, and (d) that separate the effects of nutritional state, vigilance and food availability on feeding rates in different group positions. 9. Reproductive success is often related to group position in breeding colonies and lekking animal species. Females probably prefer the safer territories in the group centre, but more empirical data are required to test this hypothesis. 10. Position-related differences in parasitism rate between group members are well documented with per capita rate of parasitism being lower in the centre of groups than at the periphery.(ABSTRACT TRUNCATED AT 400 WORDS)

Influence of sequential exposure to R-verapamil or B8509-035 on rhodamine 123 accumulation in human lymphoblastoid cell lines

Modulators for the reversal of multidrug resistance such as R-verapamil and B8509-035, a dihydropyridine, effectively overcome multidrug resistance in vitro and are currently undergoing clinical trial. One problem with their use is the application protocol; the question as to whether they should be given by continuous administration or in sequential doses in combination with the cytotoxic drugs has to be addressed. Therefore, we examined the influence of the exposure time and the sequence of modulator administration on the active transport of the fluorescent dye rhodamine 123 (R123), a substrate for the P-glycoprotein, in the resistant lymphoblastoid cell line VCR1000 and the parental nonresistant cell line CCRF-CEM. Our results demonstrate the importance of coadministration of R-verapamil and the cytotoxic agent for the modulation of multidrug resistance, whereas the exposure sequence does not seem to be such an essential parameter in the case of B8509-035. This observation should be considered for the further design of clinical studies.

Evidence for carbohydrate-independent endocytosis of tissue-type plasminogen activator by liver cells

In the liver, tissue-type plasminogen activator (t-PA) is endocytosed by hepatic parenchymal (PC), endothelial (EC) and Kupffer (KC) cells. Although the endocytosis is receptor-mediated, it remains a matter of discussion which receptors are involved in this catabolic process. To evaluate the role of a protein-specific receptor, as well as the possible involvement of the galactose receptor on PC and the mannose receptor on EC, we have employed different glycosylation variants of t-PA in biochemical and immunocytochemical studies. Partial or total removal of carbohydrate side-chains by endoglycosidases did not prevent clearance and hepatic endocytosis of t-PA by either of the liver cell types. Blockade of the galactose and mannose receptors by co-application of a large excess of the glycoprotein ovalbumin remained without effect on the binding and uptake of t-PA by hepatic cells. However, the contribution of different liver cell types to the hepatic clearance of t-PA was to a certain extent dependent on the type of oligosaccharide chains removed. The mannose receptor on EC is partially responsible for the clearance of t-PA by this cell type, whereas the galactose receptor does not seem to be involved in this process. The results obtained in this study further demonstrate that the major portion of the hepatic catabolism of t-PA is independent of its carbohydrate side-chains.

[Anti-basement membrane antibody disease of the lungs without clinical kidney involvement]

Anaemia (haemoglobin 10.7 g/dl) and small spotty infiltrates in both lungs were found in an 18-year-old man who had increasing haemoptysis over the preceding 3 weeks. Bronchoscopy revealed diffuse bilateral pulmonary haemorrhage. Further diagnostic measures provided no evidence of involvement of other organs, in particular the kidneys. The demonstration of anti-basement membrane antibodies confirmed the diagnosis of a disease within the group of immune-induced alveolar haemorrhage. The radiological signs in the lungs regressed over 3 weeks of administering prednisone, initially 100 mg daily, then 60 mg daily, and the patient was discharged. While being treated as an out-patient, with reduction of prednisone to 10 mg daily, the haemoptysis recurred so that a single dose of cyclophosphamide, 1.5 g, was added to the immunosuppressive treatment. There was no further haemoptysis and the prednisone was discontinued after having been given for 15 months. The patient has now been in complete clinical remission for 3 years and anti-basement membrane antibodies are no longer demonstrable. At no time was there any evidence of renal involvement in the sense of the classical Goodpasture's syndrome.

Neuropeptide Y1 subtype pharmacology of a recombinantly expressed neuropeptide receptor

Neuropeptide Y (NPY) is an important central and peripheral modulator of neural and endocrine functions. This neuropeptide interacts with at least two pharmacologically distinct receptors, termed Y1 and Y2. At Y1 receptors, the NPY analog [Leu31,Pro34] NPY, but not the carboxyl-terminal fragment NPY-(18-36), displaces radiolabeled NPY and the sequence-related peptide YY, whereas Y2 receptors exhibit the opposite selectivity. We have used cultured mammalian 293 cells for the high level transient expression of a previously cloned putative neuropeptide receptor of rat brain. We report that this receptor displays the ligand binding properties and selectivity of a Y1 receptor, with a single high affinity site for 125I-NPY (Kd, 0.7 +/- 0.2 nM). The functionality of the recombinantly expressed receptor was demonstrated by an inhibition of adenylyl cyclase and a concomitant mobilization of intracellular Ca2+.

Endocytosis and intracellular processing of tissue-type plasminogen activator by rat liver cells in vivo

Endocytosis of tissue-type plasminogen activator (t-PA) by different types of rat liver cells was studied in immunocytochemically labelled cryosections as well as in biochemical experiments. For morphological localization of the ligand in different endocytic compartments involved in its catabolism, rat livers were fixed at various times (1-24 min) after injection of t-PA. Late-endosomal and lysosomal compartments were identified by double-labelling the sections with antibodies to the lysosomal proteins glycoprotein Igp 120 and cathepsin D. In liver t-PA was localized in sinusoidal endothelial cells (EC), parenchymal cells (PC) and to some extent in Kupffer cells (KC), indicating that it is internalized and degraded in all three cell types. In specimens fixed 6 min after injection PC, EC and KC were found to contribute to 69, 24 and 7% respectively of total t-PA endocytosed. The transfer from late endosomes to lysosomes was found to be faster in EC than in PC. The morphological findings were supported by studies of the endocytic mechanisms employing isolated perfused livers and primary hepatocytes. The presence of monensin, an inhibitor of lysosomal protein degradation, reduced the amount of t-PA degraded to about 50% of the control values. The catalytic site seems not to be required for the catabolism of t-PA in hepatic cells. The inhibition of t-PA by D-phenylalanyl-L-prolylarginyl-chloromethane did not influence receptor recognition and catabolic processing, as determined in morphological studies using labelled cryosections, in binding studies employing liver cell membranes and primary hepatocytes, as well as in liver-perfusion experiments.

Pharmacokinetics and hepatic catabolism of tissue-type plasminogen activator

Recombinant tissue-type plasminogen activator (rt-PA, alteplase, Actilyse, Activase; CAS 105857-23-6) is the most effective agent currently available for thrombolytic therapy of life-threatening diseases such as acute myocardial infarction. It acts by rapid, clot-specific lysis of pathological thrombi, with only limited effects on systemic hemostasis. Pharmacokinetics of rt-PA have been extensively characterized in animal species and man, and can be generally described by a 3-compartment model. Preferred analytical methods for rt-PA in plasma are ELISA and chromogenic activity assays. The dominant plasma half-life of rt-PA in myocardial infarction patients is short (3.6 min), which allows excellent control of plasma levels during therapy. Steady-state plasma concentrations effecting coronary thrombolysis using the current dosage regimen are 2.2 micrograms/ml. A deep compartment results in elevated rt-PA concentrations several hours after termination of infusions, which may contribute to short-term maintenance of patency of reperfused blood vessels. Clearance of rt-PA can be saturated in animals at very high plasma concentrations (Km = 12-15 micrograms/ml), however, pharmacokinetics in clinical settings are linear. Clearance occurs via hepatic receptor mediated endocytosis and intracellular degradation in liver parenchymal, endothelial and Kupffer cells. The catabolism involves coated pits, coated vesicles, endosomes, and finally degradation in lysosomes. Current evidence supports the existence of hepatic receptors recognizing carbohydrate as well as polypeptide determinants in rt-PA. In conclusion, increasing knowledge of rt-PA pharmacokinetics will contribute to the optimization of new clinical dosage regimens, such as front-loaded infusions and boluses, and to the identification of novel molecular targets for pharmacologic control of rt-PA catabolism and of circulating fibrinolytic activity.