[Digital knowledge in the coat pocket -- hand-held personal digital assistants in radiology]

The personal digital assistant (PDA) enables the independent access to large data in a pocket-sized format. The applications for hand-held computers are growing steadily and can support almost any kind of problem. An overview of the available hardware and software is provided and evaluated. Furthermore, the use of the PDA in the clinical daily routine is described. In view of the numerous software programs available in radiology, the range of software solutions for radiologists is presented. Despite the high acquisition cost, the PDA has already become the digital assistant for the radiologist. After a short time of getting used to the PDA, nobody wants to miss it at work or at home. New technical features and available software programs will continuously increase the integration of the PDA into the medical workflow in the near future.

[Metabolic and cardiovascular response in strength endurance training]

The purpose of this empirical study was: 1 (st): To evaluate the strain in three specifically trained training groups (untrained, athletics and wrestler) by a constant stress (20-RM) in a typically strength endurance training. 2 (nd): To predict the strain in strength endurance training over six sets. The results are: The workload as an objective parameter decreased over the six sets and there was a significant difference between the three different groups. Lactic acid concentration increased in the same way over the sets and there was no statistic difference between the groups. The findings of heart rate, systolic blood pressure, double product and rating of perceived exertion remain clear. There was no healthy risk by usage rate in the set in the three groups.

[The use of cross-sectional imaging modalities in the diagnosis of heart valve diseases]

Exact visualization of valve morphology seems to be possible with the cross-sectional imaging modalities, magnetic resonance imaging (MRI) and the recently introduced technique of multi-detector computed tomography (MDCT). These techniques are used, if other non-invasive imaging modalities, like echocardiography, fail or provide only insufficient information. This commonly occurs in the assessment of right ventricular valves. Quantification of valve stenosis is possible by calculating valve orifice area, which can be performed with MRI and MDCT. An estimation of the instantaneous peak gradient can only be achieved by MR flow measurements. MR flow measurement is a reliable method to quantify the degree of mild to moderate stenoses. Quantification of valve regurgitation is possible by measurement of the regurgitation fraction with MR flow measurements as well as with MR volumetry/CT volumetry. But only the MR flow measurement is suitable for the quantification of valve regurgitation in patients with multiple valves involved or cardiac shunting. MRI and probably MDCT are the most reliable methods in the evaluation of ventricular volumes and therefore suitable for the follow-up in patients with valvular heart disease, because changes in volumes are important for therapeutic decisions in these patients. The crucial advantages of MRI compared to CT in the diagnostic of valvular heart diseases however are the absence of radiation exposure, the possibility of quantitative evaluation of valves function using flow measurements and the higher temporal resolution as compared to MDCT.

Dysphonia subsequent to severe traumatic brain injury: comparative perceptual, acoustic and electroglottographic analyses

We tested the applicability of the Goettinger Hoarseness Diagram (GHD) for quantitative evaluation of voice disorders after severe traumatic brain injury (TBI) and compared the obtained data with those from established voice analysis systems such as the Multi-Dimensional Voice Program (MDVP), electroglottography (EGG) and perceptual ratings using sustained vowel productions from 10 patients with TBI dysarthrophonia at late stages postinjury and of 10 healthy control speakers. Statistical analyses revealed significant intergroup differences with respect to various acoustic and perceptual measures, i.e., irregularity component, noise component, noise-to-harmonic ratio, shimmer, jitter, roughness, creakiness, strained-strangledness, hypernasality. By contrast, the considered EGG estimates, i.e., open quotient and speed quotient, did not allow for separation of patients and controls. In addition, the two GHD components exhibited close correlations to perceived roughness and creakiness, on the one hand, and breathiness and, to some degree, nasality, on the other, whereas the MDVP parameters failed to differentiate between these two perceptual modes of phonation.

SIM--simultaneous inverse filtering and matching of a glottal flow model for acoustic speech signals

A new method "simultaneous inverse filtering and model matching" (SIM) is proposed that allows one to calculate voice source measures without any user interaction. It is based on the discrete all-pole modeling (DAP) technique for inverse filtering (IF), which is modified to include a model of the glottal flow as integral part [LF model, Fant et al., STL-QPSR (Stockholm) 4/1985, 1-13 (1986)]. As the correct LF parameters are initially unknown, they are estimated in an iterative procedure using multi-dimensional optimization techniques that are initialized according to the results of an exhaustive search. The error criteria applied reflect how well the IF is performed after the spectral contribution of the glottal flow has been removed. The resulting optimal LF parameter constellation serves as the basis to calculate 11 voice source measures. The performance was evaluated using synthesized signals and recordings of natural utterances. For the synthesized signals, the accuracy to reproduce the original parameters was high (correlations exceeding 0.88) for measures where the starting point of the glottal cycle did not enter explicitly. Errors were smaller compared to conventional estimation methods where the measures were estimated from the IF signal. The analysis of natural utterances indicates that problems still exist with regard to robustness, but that under advantageous conditions the open quotient, the speed quotient, the closing quotient, the parabolic spectral parameter, and the negative peak amplitude of the glottal flow derivative can indeed be determined automatically by the SIM method.

Particulate air pollution is associated with an acute phase response in men; results from the MONICA-Augsburg Study

AIMS

Episodes of increased air pollution are associated with increases in hospital admissions for cardiovascular disease. Even modest acute phase responses are associated with increased risk of coronary heart disease. The study investigates whether induction of an acute phase response by exposure to air pollution may contribute to cardiovascular pathology.

METHODS AND RESULTS

A prospective cohort study based on a survey in 1984/85 with a 3-year follow-up was conducted in 631 randomly selected men aged 45 to 64 years free of cardiovascular disease at entry 1984/85. Serum C-reactive protein concentrations were determined by a high sensitivity immunoradiometric assay. C-reactive protein concentration was increased in association with the 1985 air pollution episode. In multivariate analyses, elevated concentrations were independently associated with concentrations of total suspended particles and the sulphur dioxide episode. At ambient concentrations of pollution, as noted during the 1985 air pollution episode, the odds of observing C-reactive protein concentrations above 5.7 mg. l(-1)(>90th percentile) tripled, and increases of 26 microg. m(-3)total suspended particles (mean of 5 days) raised the odds of C-reactive protein levels 50% above the 90th percentile.

CONCLUSIONS

Exposure to current levels of particulate matter in the atmosphere elicits an acute phase response in randomly selected healthy middle-aged men, which may contribute to the increased cardiovascular risk caused by air pollution.

Role of novel markers of inflammation in patients with stable coronary heart disease

The role of novel markers of inflammation in patients with coronary heart disease (CHD) is still unclear. We conducted a case-control study to assess the association between various markers of inflammation and the presence and severity of chronic stable CHD. We included 312 clinically stable patients with angiographically documented CHD, aged 40 to 68 years. Voluntary blood donors (n = 479) matched for age and gender served as controls. High-sensitivity C-reactive protein, serum amyloid A, plasminogen activator inhibitor-1 activity, von Willebrand factor, fibrinogen, plasma viscosity, albumin, and neutrophils were determined. The severity of CHD was evaluated by 3 coronary scoring systems: the clinical 1- to 3-vessel disease score, the American Heart Association extension score (1 to 15 segments), and the Gensini score. All markers of inflammation were highly significantly elevated (all p <0.005) in patients with stable CHD compared with controls. After multivariable adjustment by means of logistic regression analysis, the association between CHD and fibrinogen, plasma viscosity, von Willebrand factor, and plasminogen activator inhibitor-1 activity remained substantial, whereas it decreased in high-sensitivity C-reactive protein, serum amyloid A, and neutrophils. The combination of > or = 2 markers of inflammation was associated with a strongly increased risk of CHD. No association between markers of inflammation and any of the coronary scores applied was found. These results document an independent association between most of the markers of inflammation and chronic CHD, even in clinically stable patients. The combination of several of these biochemical markers, i.e., the determination of an "inflammatory risk profile," may be useful to further stratify cardiovascular risk.

Parameters influencing the determination of liposome lamellarity by 31P-NMR

The lamellarity of liposomes influences to a great extent the encapsulation efficiency, the efflux rate of liposomally encapsulated material, and the fate of a drug after cellular uptake. 31P-NMR in combination with the use of chemical shift reagents has been described for the determination of lamellarity of liposomes and this study was performed to evaluate the applicability of 31P-NMR analysis as published in the past. To date, very few details about the required conditions throughout the measurements are known. In this study the influence of various parameters on the measurement, such as different buffers with changing ion concentrations, varying pH and different shift reagents at increasing concentrations was investigated. Results were discussed by using cryo-electronmicroscopy as a reference method. The data of this study show that 31P-NMR might not result in the correct determination of liposome lamellarity, depending on the experimental settings and the shape of the liposomes.

Association between C-reactive protein and features of the metabolic syndrome: a population-based study

OBJECTIVE

To assess the association of circulating levels of C-reactive protein, a sensitive systemic marker of inflammation, with different components of the metabolic syndrome.

RESEARCH DESIGN AND METHODS

Total cholesterol (TC), HDL cholesterol, triglycerides, uric acid, BMI , and prevalence of diabetes and hypertension were assessed in 747 men and 956 women aged 18-89 years who were participating in the population-based National Health and Nutrition Survey, which was carried out in former West Germany in 1987-1988.

RESULTS

There was a statistically significant positive crude correlation between C-reactive protein and TC (R = 0.19), TG (R = 0.29), BMI (R = 0.32), glucose (R = 0.11), and uric acid (R = 0.14) (all P < 0.0001). A negative correlation was found between C-reactive protein and HDL cholesterol (R = 0.13, P < 0.0001). The age-adjusted geometric means of C-reactive protein concentrations in subjects grouped according to the presence of 0-1, 2-3, and > or =4 features of the metabolic syndrome were 1.11, 1.27, and 2.16 mg/l, respectively, with a statistically highly significant trend (P < 0.0001).

CONCLUSIONS

The data suggest that a variety of features of the metabolic syndrome are associated with a systemic inflammatory response.

Two-year clinical performance of two primer adhesives on class V restorations

The prime purpose of this clinical trial was to examine the clinical quality and retention rate of resin composite in connection with two recently developed acetone-based primer adhesives in Class V lesions according to ADA Clinical Protocol Guidelines for Dentin and Enamel Adhesive Materials. All cavities were nonretentive and predominantly in dentin (mixed Class V lesions). Total bonding was not limited either by sub-base or by base materials. All the trial restorations were placed under rubber dam. Group 1 (Version 16-135-1) and group 2 (Version 17-17-1) consisted of 42 patients with 46 trials and 38 patients with 43 fillings, respectively. The mean follow-up period and the recall response at the end of the study of group 1 were 22.8 months and 92.9% and of group 2 were 22.4 months and 94.7%. The trial restorations of both groups maintained their predominantly rated USPHS-Code Alpha level within the follow-up period. The cumulative failure rate of two trials in group 1 and four in group 2 determined a failure percentage of 4.4% and 9.3%, respectively, which is within the ADA-18 month limit of <10% Charlie. The Version KL 16-135-1 came into the market as Prime & Bond(R) 2.1, and the other one turned out to be Dyract Adhesive(R) PSA, which was primarily introduced as a single-component adhesive for compomer restorative Dyract(R) (Dentsply DeTrey, Germany).

Interaction patterns between dentin and adhesive on prepared class V cavities in vitro and in vivo

The interface between dentin and an acetone-based single-component adhesive system (Prime&Bond 2.1, DeTrey Dentsply, Germany) was morphologically investigated by scanning electron microscopy (SEM). Interaction patterns of human teeth were correlated in vivo and in vitro. The SEM examination proved that the formation of a hybrid and an adhesive layer, the peri- and intratubular adhesive penetration, as well as hiatus and nanoleakage formation were no different on vital and nonvital dentin within the limitation of the experimental arrangement of this study.

Immunoradiometric assay of circulating C-reactive protein: age-related values in the adult general population

BACKGROUND

: Increased values of C-reactive protein (CRP), the classical acute phase protein, within the range below 5 mg/L, previously considered to be within the reference interval, are strongly associated with increased risk of atherothrombotic events, and are clinically significant in osteoarthritis and neonatal infection.

METHODS

: A robust new polyclonal-monoclonal solid- phase IRMA for CRP was developed, with a range of 0.05-10.0 mg/L.

RESULTS

: Plasma CRP values in general adult populations from Augsburg, Germany (2291 males and 2203 females; ages, 25-74 years) and Glasgow, Scotland (604 males and 650 females; ages, 25-64 years) were very similar. The median CRP approximately doubled with age, from approximately 1 mg/L in the youngest decade to approximately 2 mg/L in the oldest, and tended to be higher in females.

CONCLUSION

: This extensive data set, the largest such study of CRP, provides valuable reference information for future clinical and epidemiological investigations.

Acoustic voice analysis by means of the hoarseness diagram

The hoarseness diagram (Michaelis, Fröhlich, & Strube, 1998a) has been proposed as a new approach to describe different acoustic properties of voices. To test its performance in the analysis of pathologically disturbed and normal voices five requirements are suggested that should be met by any acoustic voice-analysis protocol to be used in voice research and clinical practice. The hoarseness diagram is then tested with regard to these requirements. Individual voices are found to show a satisfactory localization in the diagram. Aspects of stationarity are discussed in the context of four case studies. The different cases illustrate that changes in the acoustic analysis results are observed if the voice-generation conditions change, whereas results are stationary if phonation conditions do not change. Different pathological voice groups defined on grounds of the specific phonation mechanism are found to map to specific regions of the hoarseness diagram, with differences between group locations being significant. All results can be interpreted without exceptions if the two hoarseness diagram coordinates are taken to reflect the vibrational irregularity of the voice-generation mechanisms on the one side and the degree of closure of the vibrating structures on the other side. The hoarseness diagram and its underlying algorithms are thus shown to constitute a useful approach to acoustic voice analysis in research and clinical practice. The tests themselves demonstrate several application possibilities, including the quantitative monitoring of individual voices.

Chronic infection with Helicobacter pylori does not provoke major systemic inflammation in healthy adults: results from a large population-based study

It has been suggested that chronic infection with Helicobacter pylori (H. pylori), in particular infection with virulent strains producing the cytotoxin-associated protein CagA, may increase the risk of coronary heart disease by generation of a persistent low-grade inflammatory stimulus. We assessed the relation between serological markers of H. pylori infection and various markers of systemic inflammation in a population-based sample of 1834 men and women aged 18-88. A total of 39.3% of the sample had a positive IgG response, and among these a slight majority was CagA positive. Infection with H. pylori was unrelated to C-reactive protein and the leukocyte count, regardless of CagA status. There was an inverse relation between H. pylori infection and serum albumin. The adjusted OR (95% CI) of an albumin level in the bottom versus the top third were 2.2 (1.5-3.1) and 2.0 (1.4-3.1) for infection with CagA-positive and CagA-negative H. pylori strains, respectively. These results do not support the hypothesis that chronic infection with virulent H. pylori strains provokes major systemic inflammation. The mechanisms underlying the inverse association between H. pylori infection and serum albumin and the clinical relevance of this finding require further research.

C-Reactive protein, a sensitive marker of inflammation, predicts future risk of coronary heart disease in initially healthy middle-aged men: results from the MONICA (Monitoring Trends and Determinants in Cardiovascular Disease) Augsburg Cohort Study, 1984 to 1992

BACKGROUND

Inflammatory reactions in coronary plaques play an important role in the pathogenesis of acute atherothrombotic events; inflammation elsewhere is also associated with both atherogenesis generally and its thrombotic complications. Recent studies indicate that systemic markers of inflammation can identify subjects at high risk of coronary events.

METHODS AND RESULTS

We used a sensitive immunoradiometric assay to examine the association of serum C-reactive protein (CRP) with the incidence of first major coronary heart disease (CHD) event in 936 men 45 to 64 years of age. The subjects, who were sampled at random from the general population, participated in the first MONICA Augsburg survey (1984 to 1985) and were followed for 8 years. There was a positive and statistically significant unadjusted relationship, which was linear on the log-hazards scale, between CRP values and the incidence of CHD events (n=53). The hazard rate ratio (HRR) of CHD events associated with a 1-SD increase in log-CRP level was 1.67 (95% CI, 1.29 to 2. 17). After adjustment for age, the HRR was 1.60 (95% CI, 1.23 to 2. 08). Adjusting further for smoking behavior, the only variable selected from a variety of potential confounders by a forward stepping process with a 5% change in the relative risk of CRP as the selection criterion, yielded an HRR of 1.50 (95% CI, 1.14 to 1.97).

CONCLUSIONS

These results confirm the prognostic relevance of CRP, a sensitive systemic marker of inflammation, to the risk of CHD in a large, randomly selected cohort of initially healthy middle-aged men. They suggest that low-grade inflammation is involved in pathogenesis of atherosclerosis, especially its thrombo-occlusive complications.

C-reactive protein frequently colocalizes with the terminal complement complex in the intima of early atherosclerotic lesions of human coronary arteries

There is increasing evidence that complement activation may play a role in atherogenesis. Complement proteins have been demonstrated to be present in early atherosclerotic lesions of animals and humans, and cholesterol-induced atherosclerotic lesion formation is reduced in complement-deficient animals. Potential complement activators in atherosclerotic lesions are now a subject matter of debate. C-reactive protein (CRP) is an acute-phase protein that is involved in inflammatory processes in numerous ways. It binds to lipoproteins and activates the complement system via the classic pathway. In this study we have investigated early atherosclerotic lesions of human coronary arteries by means of immunohistochemical staining. We demonstrate here that CRP deposits in the arterial wall in early atherosclerotic lesions with 2 predominant manifestations. First, there is a diffuse rather than a focal deposition in the deep fibroelastic layer and in the fibromuscular layer of the intima adjacent to the media. In this location, CRP frequently colocalizes with the terminal complement complex. Second, the majority of foam cells below the endothelium show positive staining for CRP. In this location, no colocalization with the terminal complement proteins can be observed. Our data suggest that CRP may promote atherosclerotic lesion formation by activating the complement system and being involved in foam cell formation.

[Objective description of voice quality using the hoarseness diagram]

The need for an objective assessment of voice quality can be seen in the increasing use of acoustic analysis methods for clinical diagnosis and research. The hoarseness diagram allows clinicians to objectively describe even highly disturbed or aphonic votes. Its application possibilities are illustrated in three case studies in which changes in voice quality were monitored during voice rehabilitation. The distributions of voice groups that were defined on the basis of specific pathophysiological phonation conditions were then compared for their acoustic differences. The groups comprised various phonation conditions after the resection of laryngeal tumors and different types of laryngeal paralyses. Interpretation of the results suggests a direct correspondence of the hoarseness diagram coordinates and the irregularity of vibration on the one side and the degree of glottal closure on the other. This illustrates the potential usefulness of the hoarseness diagram in a clinical context.

Selection and combination of acoustic features for the description of pathologic voices

The glottal to noise excitation ratio (GNE) is an acoustic measure designed to assess the amount of noise in a pulse train generated by the oscillation of the vocal folds. So far its properties have only been studied for synthesized signals, where it was found to be independent of variations of fundamental frequency (jitter) and amplitude (shimmer). On the other hand, other features designed for the same purpose like NNE (normalized noise energy) or CHNR (cepstrum based harmonics-to-noise ratio) did not show this independence. This advantage of the GNE over NNE and CHNR, as well as its general applicability in voice quality assessment, is now tested for real speech using a large group of pathologic voices (n = 447). A set of four acoustic features is extracted from a total of 22 mostly well-known acoustic voice quality measures by correlation analysis, mutual information analysis, and principal components analysis. Three of these measures are chosen to assess primarily different aspects of signal aperiodicity, while the fourth one indicates the noise content of the signal. All analysis methods lead to the same feature set that consists of a measure of period correlation, jitter, shimmer, and GNE. The two-dimensional projection of this set named "hoarseness diagram" allows a graphical illustration of voice quality that can be easily interpreted.

Effects of hormone replacement therapies on fibrinogen and plasma viscosity in postmenopausal women

In women, cardiovascular morbidity and mortality sharply increase after the onset of menopause. There is substantial evidence that hormone replacement therapy (HRT) may decrease the risk of coronary heart disease (CHD); however, the mechanisms of this preventive effect are unclear. We investigated the association between HRT and plasma viscosity as well as fibrinogen levels in postmenopausal women of a population-based sample (n=300, age 52-65 years). A total of 94 women used HRT; of these, 50 took oestrogen monotherapy and 44 used oestrogen-progesterone combinations. HRT was associated with significantly lower fibrinogen concentrations (2.32 v 2.68 g/l, P<0.001) and decreased plasma viscosity (1.147 v 1.176 mPa/s, P=0.01). Multivariate analyses controlling simultaneously for the effects of age, smoking, body mass index, and use of diuretics confirmed decreased fibrinogen and plasma viscosity values in women using HRT. A trend towards lower plasma viscosity (1.139 v 1.160 mPa/s) and plasma fibrinogen (2.28 v 2.44 g/l) was observed in women on oestrogen-progesterone combinations as compared with oestrogen monotherapy users: however, after controlling for the above-mentioned variables these differences were not statistically significant. This study demonstrates decreased plasma viscosity in women on HRT. Improved rheology offers a mechanism by which HRT lowers the risk of CHD in postmenopausal women.

Seasonal variations of rheological and hemostatic parameters and acute-phase reactants in young, healthy subjects

The incidence of cardiovascular diseases is increased in winter months. Recent studies have shown seasonal changes in plasma viscosity, fibrinogen, and factor VII activity with elevated levels during winter. An increase in these factors generates a "hypercoagulable state," which may lead to a rise in cardiovascular morbidity and mortality. It has been suggested that an increase in upper respiratory infections might be the underlying cause for the raised acute-phase reactants, in particular fibrinogen, during the winter season. We investigated seasonal variations of 26 parameters, determining blood rheology and hemostasis in 16 healthy volunteers (8 men and 8 women) aged 20 to 41 years. They were seen at monthly intervals over a period of 1 year. Seasonal variation with peak fitted values in the winter months was found for plasma viscosity (P < .001 for the seasonal difference), red blood cell deformability (P < .001), whole blood viscosity (P < .001), hemoglobin (P < .001), hematocrit (P < .001), mean corpuscular volume (P = .001), platelet count (P = .01), alpha 1-glycoprotein (P < .001), fibrinogen (measured by immunonephelometry; P < .001), plasminogen activator inhibitor-1 (P = .002), LDL cholesterol (P = .003), and triglyceride levels (P < .001). HDL cholesterol (P < .001) and cortisol (P = .001) showed inverse seasonal patterns, with a maximum during summertime. No statistically significant seasonal variations were seen for red blood cell aggregation, complement factor C4, total cholesterol, ceruloplasmin, haptoglobin, white blood cell count, and plasminogen. These data do not support the hypothesis that increased morbidity and mortality from cardiovascular diseases during winter may be mainly attributable to increased synthesis of acute-phase proteins due to infections. The cause for the seasonal variations in rheological and hemostatic parameters remains unclear and should be studied in more detail.

Predictors of bad and good outcome of lumbar spine surgery. A prospective clinical study with 2 years' follow up

STUDY DESIGN

Based on prospective assessment, patients with lumbar disc surgery were examined to determine reliable predictors for clinical outcome.

OBJECTIVES

The prognostic value of a screening checklist developed in a previous study was evaluated in a 2-year follow-up.

SUMMARY OF BACKGROUND DATA

Outcome studies of lumbar disc surgery document a success rate between 49-90%. It has been shown that a number of medical history data and sociodemographic and psychodiagnostic findings are of prognostic value for the outcome of lumbar spine surgery.

METHODS

In addition to clinical and neuroradiologic examinations, 164 patients took part in a standardized interview. Eighty-two percent participated in a follow-up performed 2 years after the operation. Preoperative findings, outcome, and prediction of three diagnostic subgroups were compared. Eighty-three (51%) patients had disc herniation only, 29 (18%) had disc herniation and other relevant back diagnoses, and 51 (31%) had no disc herniation but had other relevant back diagnoses.

RESULTS

In patients with disc herniation only, good results were observed in 53%, moderate in 19%, and bad in 28%. The accuracy of prediction of the postoperative result was 75% for the patients with good outcome and 86% for those with bad outcome. In the group of patients with diagnoses other than disc herniation, the success rate of the operation was 38% good, 28% moderate, and 41% bad, but the predictor score was not as useful as for the other groups.

CONCLUSION

Patients with a high risk of a bad operation outcome after lumbar discectomy could be identified preoperatively. It is suggested that those patients take part in a pain management approach instead of or in addition to surgical intervention.

Effect of hyperglycaemia on gallbladder motility in type 1 (insulin-dependent) diabetes mellitus

Patients with diabetes mellitus are at increased risk of developing gallstones. This has been attributed, among other factors, to alterations in gallbladder motility in the presence of autonomic neuropathy. Since high blood glucose concentrations impair gastric emptying in diabetic patients, we have investigated the effect of acute hyperglycaemia on gallbladder motility. Seven Type 1 (insulin-dependent) diabetic patients were studied twice during euglycaemia (blood glucose 5 mmol/l) and hyperglycaemia (blood glucose 15 mmol/l) using a clamp technique. In addition, seven healthy volunteers were studied during euglycaemia and hyperglycaemia. Gallbladder volumes, measured with ultrasonography, were studied before and during infusion of step-wise increasing doses of cholecystokinin-33, 0.25, 0.5 and 1.0 Ivy Dog Unit.kg-1.h-1, each dose for 30 min. Mean basal gallbladder volumes were not significantly different in the four experiments. Administration of cholecystokinin resulted in significant (p < 0.05) dose-dependent reductions in gallbladder volume in all experiments. During euglycaemia the gallbladder contraction in diabetic patients was not significantly different from the control subjects. During hyperglycaemia the gallbladder contraction in the diabetic patients was significantly (p < 0.05) reduced compared to euglycaemia only during infusion of 0.25 Ivy Dog Unit.kg-1.h-1 of cholecystokinin (19 +/- 6% vs 33 +/- 6%). Compared to euglycaemia, during hyperglycaemia the gallbladder contraction in the control subjects was significantly (p < 0.05) reduced during infusion of 0.25, 0.5 and 1.0 Ivy Dog Unit.kg-1.h-1 of cholecystokinin (14 +/- 4% vs 31 +/- 3%; 42 +/- 6% vs 65 +/- 5%; 74 +/- 4% vs 90 +/- 3%, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

Subunit interactions of GTP-binding proteins

Fluorescence energy transfer [cf. Förster, T. (1948) Ann. Phys. 6, 55-75] was tested for its suitability to study quantitative interactions of subunits of G0 with each other and these subunits or trimeric G0 with the beta 1-adrenoceptor in detergent micelles or after reconstitution into lipid vesicles [according to Feder, D., Im, M.-J., Klein, H. W., Hekman, M., Holzhöfer, A, Dees, C., Levitzki, A., Helmreich, E. J. M. & Pfeuffer, T. (1986) EMBO J. 5, 1509-1514]. For this purpose, alpha 0- and beta gamma-subunits and trimeric G0 purified from bovine brain, the beta gamma-subunits from bovine rod outer segment membranes and the beta 1-adrenoceptor from the turkey erythrocyte were all labelled with either tetramethylrhodamine maleimide or fluorescein isothiocyanate under conditions which leave the labelled proteins functionally intact. In the case of alpha 0- and beta gamma-interactions, specific high-affinity binding interactions (Kd approximately 10 nM) and nonspecific low-affinity binding interactions (Kd approximately 1 microM) could be readily distinguished by comparing fluorescence energy transfer before and after dissociation with 10 microM guanosine 5'-O-[gamma-thio]triphosphate and 10 mM MgCl2 where only low-affinity binding interactions remained. Interactions between alpha 0- and beta gamma-subunits from bovine brain or from bovine retinal transducin did not differ much. The beta gamma-subunits from bovine brain were found to bind with high transfer efficiency and comparable affinities to the hormone-activated and the nonactivated beta 1-receptor reconstituted in lipid vesicles: Kd = 100 +/- 20 and 120 +/- 20 nM, respectively; however, beta gamma-subunits from transducin appeared to bind more weakly to the beta 1-adrenoceptor than beta gamma-subunits from bovine brain. Separated purified homologous alpha 0- and beta gamma-subunits from bovine brain interfered mutually with each other in binding to the beta 1-adrenoceptor presumably because they had a greater affinity for each other than for the receptor. These findings attest to the suitability of fluorescence energy transfer for studying protein-protein interactions of G-proteins and G-protein-linked receptors. Moreover, they supported the previous finding [Kurstjens, N. P., Fröhlich, M., Dees, C., Cantrill, R. C., Hekman, M. & Helmreich, E. J. M. (1991) Eur. J. Biochem. 197, 167-176] that beta gamma-subunits can bind to the nonactivated beta 1-adrenoceptor.

[Prophylaxis of alcohol withdrawal syndrome in prolonged oral and maxillofacial surgery procedures]

Alcohol-addicted patients have a high risk of intercurrent complications during the postoperative period. In addition to the predisposition for infection, alcohol withdrawal syndrome is potentially life-threatening in these patients. However, this concerns only addicts, and definite preoperative diagnosis of addiction therefore is a crucial parameter in assessing the postoperative risks. In our department, 40% of maxillofacial tumor patients with a history of alcohol abuse were assessed as alcohol-addicted according to a complex diagnosis scheme. In these patients, postoperative withdrawal syndrome prophylaxis with continuous, low-dose alcohol infusion is indicated after exclusion of contraindications. If prophylaxis is impossible and differential diagnosis has confirmed a withdrawal syndrome, therapy must take into account the patient's symptoms and the latest neurobiochemical findings on withdrawal-related imbalances in neuronal transmitter systems.

Binding of alpha- and beta gamma-subunits of Go to beta 1-adrenoceptor in sealed unilamellar lipid vesicles

First, we describe a preparation of sealed unilamellar lipid vesicles. When this preparation was subjected to sucrose density gradient centrifugation, two rather uniform fractions emerged, one consisting of lighter lipid-rich vesicles with average diameters ranging over 150-200 nm (fraction I), the other consisting of heavier vesicles with average diameters ranging over 30-70 nm (fraction II). When the lipid mixture containing dimyristoylglycerophosphocholine, cholesterol, dipalmitoylglycerophosphoserine and dipalmitoylglycerophosphoethanolamine at molar ratios of 54:35:10:1 was reconstituted with alpha- and beta gamma-subunits of Go-proteins purified to homogeneity from bovine brain, the lipid-rich lighter vesicle fraction I took up these subunits nearly exclusively. Whereas, when a beta 1-adrenoceptor preparation purified from turkey erythrocyte membranes was reconstituted, it was found nearly completely in the smaller heavier vesicle fraction II where it was incorporated inside-out. On co-reconstitution of either alpha o or beta gamma alone with beta 1-adrenoceptors, some of these subunits appear together with beta 1-adrenoceptors in the small vesicle fraction II, but much more alpha o was bound to the receptor in the presence of beta gamma-subunits. The observations reported are novel and surprising in several respects: firstly, they suggest that beta gamma-subunits can bind to the non-activated beta 1-receptor where they may serve as an anchor for alpha-subunits. Secondly, the binding of alpha o- and beta gamma-subunits to the beta 1-adrenoceptors enhances the basal GTPase activity of alpha o. Thirdly, since the binding domains of the beta 1-adrenoceptor for G-proteins were facing outwards in our sealed vesicle preparations, it follows that interactions of G-proteins with the beta-receptor can occur at the aqueous membrane interface as was postulated originally by M. Chabre [Trends Biochem. Sci. 12, 213-215 (1987)] for the transducin-rhodopsin interactions. Finally, the binding of Go-subunits from bovine brain to a beta 1-adrenoceptor from turkey erythrocytes was not expected, since these polypeptides are not likely to be physiological partners.

[Evaluation of intratumoral bleomycin application in a tumor model and in a clinical pilot study]

In a total of 21 patients with squamous cell carcinomas of the oral mucosa 26.9% of the total volume of 57Co-Bleomycin injected into the tumor was found in the blood as early as 10 min following injection. Examinations using a gamma camera demonstrated that 94.6% of the substance have cleared the tumor tissue after just 1 h. This sharp and rapid drop in activity, which was particularly pronounced in carcinomas of the tongue and the floor of the mouth, might be caused by rapid resorption due to the high degree of vascularization of the maxillofacial region. Autoradiography showed deposits of the substance in tumor-free areas of the operation specimens. It seems that the postulated advantages of intratumoral application--increased concentration and depot effect in the tumor tissue--are no longer tenable, thus large-scale clinical trials with intratumoral bleomycin treatment cannot be justified.

[Comparative studies of carcinomas of the human oral mucosa and xenografts in the nude mouse with the aid of computer-supported microscope image analysis]

The complete preservation of the original characteristics of donor tumors after xenografting into nude mice is more and more doubtful. With the aid of traditional biological methods and computer-assisted microscope image analysis the original human tumor tissues, including primary and recurrent tumors and metastases, are compared with nude mouse-grown xenografts. Squamous cell carcinomas of the oral mucosa served as original tumor tissues. Tumor takes were observed in 7 out of 12 cases. 5 transplantable lines could be established. Primaries, recurrent tumors and lymph node metastases are suitable for transplantations into nude mice and yield a comparable success rate. With one exception complete conformity between the original human tumor tissues and nude mouse-grown tumors could be found regarding the degree of differentiation and keratinizing tendency. As to the growth pattern of xenografts characterized by continuous shortening of growth periods, certain variations in the biological properties due to selection processes cannot be excluded. The results of microscope image analysis based on 35 different parameters suggest important differences within the developmental tendency of human tumor tissues and nude mouse-grown xenografts.

[Multicentric retrospective study on the carcinoma of lips and oral mucosa. Analysis of coherence between pre- and posttherapeutical categories of classification]

The coherence between prae- and posttherapeutical TNM findings had been checked up in a multicentrically registered patient material of 2,481 non-praetreated plate epithelium carcinomas of the lips and oral mucosa. Whereas the extension of the tumour has in the main been the same, the findings on lymph nodes had a trend showing essential deviations. In a two-dimensional examination of 851 histologically prepared preparations of lymph nodes, a prognostic relevance acc. to metastases had been registered for the characteristics palpation finding of the lymph node, tumour extension, tumour infiltration. Multidimensional analyses have to be realized.

[Bullet injuries in the maxillary-facial range. Report on experiences of treatment of 60 patients at the Gondar College of Medical Sciences in Ethiopia]

A report on the management of 60 patients with missile injuries to the soft and bony tissues of the maxillofacial region is given. The period between the injury and the beginning of the treatment was on the average 2.2 days. There were 15 penetrating, 36 perforating and 9 avulsive wounds. A primary wound closure was carried out after gentle debridement of the soft and bony tissues and the using of the bone suturing as the only method of fixation. In 4 cases the secundary wound closure was performed following an open wound management. There was a primary wound healing in 31 patients. The 22 cases of disturbed wound healing partly associated with osteomyelitis occurred frequently in patients suffering from perforating wounds who came to the the hospital more than 4 days following the injury.

[New aspects of therapy for alveolitis with Grisaldon]

In the GDR, Grisaldon has been used in alveolitis therapy since 1974. The results from the bacteriological testing of this preparation and the diluting and rinsing effects of saliva and blood on it arouse doubts about its antibacterial efficiency. Thrombelastographic studies demonstrated the clotting-accelerating and the marked fibrin-stabilizing effect of pure acetylsalicylic acid. In contrast to other publications, it was stated that the p-hydroxybenzoic acid propyl ester is absolutely indifferent. Histological studies on animals have shown that Grisaldon is detectable in the alveolus as a foreign body even 28 days after application, and that it decelerates wound healing.

[Analysis of hemorrhagic diatheses treated in hospital]

An analysis of the patients hospitalized for haemorrhagic diatheses during the years 1970--1976 leads to the statement that their number had been increasing. It is concluded that the number of stationary treatments might by considerably reduced by regular stomatological check-ups of these patients. Therefore, the authors advocate the establishment of several facilities for regular stomatological check-ups of this group of patients in each district of the GDR.

[Results of in vitro sperm penetration tests in cervical mucus under takings of the sequential oral contraceptive ovanon and sequilar (author's transl)]

The in vitro penetrability of cervical mucus by sperm was investigated in women who were taking Ovanon or Sequilar. Measurements were made under constant experimental conditions on every day of the cycle. The depth of penetration differed strikingly between women with normal menstrual cycles and women taking the sequential hormonal contraceptives. The penetration depth was substantially less when Sequilar or Ovanon was used. The Sequilar induced cervical sperm barrier during the entire cycle was almost as strong as that observed when combined preparations are used. During the proliferative phase of the cycle the penetration depth allowed by Ovanon was less than that observed during normal cycles but greater than that seen with Sequilar. During the secretion phase no appreciable differences in the penetrability of cervical mucus between the two contraceptives was observed. The hypothetical relationship between these data and the problem of cervical carcinoma was described.

[Comparative studies on the bacteriostatic effect of "Grisaldon" and "Cholinesalicylate gel"]

The authors present a choline salicylate gel at present on trial and compare it, by means of microbiologic studies, with Grisaldon as to composition, consistency and bacteriostatic properties. Choline salicylate showed a good bacteriostatic effect. As to Grisaldon, the conditions are considerably less favorable due to the poor solubility of acetylsalicylic acid.