[Results of a cardiovascular disease prevention study among administrative employees of a large city]. / Ergebnisse einer Herz-Kreislauf-Präventionstudie bei Angestellten einer Grossstadtverwaltung.

In parallel with the demographic changes in an increasingly ageing German population, cardiovascular diseases (HKE) are becoming increasingly frequent and thus more and more important. The main aim of this work is to derive individual preventive measures on the basis of classic risk factors. This study was performed on 101 administrative employees of a large city (71 women and 30 men). The tests included a general investigation of medical status [current individual and family case history, body mass index (BMI)] as well as the determination of the following laboratory values: glucose, HDL and LDL cholesterol. In addition, the study was completed by a job analysis, including a survey of individual health behaviour. Referring to the PROCAM study, ten traditional risk factors for cardiovascular disease (arterial blood pressure >140/90 mmHg, BMI > or =25 kg/m (2), family disposition etc.) were probed. On the basis of these results individual risk profiles for each participant were rated. A vulnerable person received individually tailored prevention recommendations, which were adapted to the individual health behaviour of the subjects. Each of the 101 study participants received a personal results and prevention bulletin with individual test results and prevention suggestions. This high effort promises a better implementation as general advice for prevention in terms of classic risk factors.

Evaluation of deformable models for femoral neck surgery.

OBJECTIVE: Using fluoroscopic images alone, it is difficult to guarantee that screws are positioned within the femoral head and neck. This study evaluates whether the introduction of deformable 3D models limiting the planning and navigation space is a helpful approach to minimizing the incidence of misplaced screws, thereby enhancing patient safety. BACKGROUND: Even though a screw may appear to lie within the femoral head and neck on fluoroscopic images, this may not, in fact, be the case. This is a particular problem for interventions such as fixation of a slipped femoral head or osteosynthesis of the femoral neck, where screws must be set close to the cortical bone without penetrating the joint or injuring the cortex of the femoral neck. METHODS: A system was developed which permits computer-based planning and navigation of screws for femoral neck fracture fixation based on fluoroscopic images. Different approaches were employed which either a) make use of a deformable model adapted to the femoral head/neck, constraining the screw positions within this model; or b) allow the user to position the screws with or without geometrical constraints on the X-rays while maintaining parallelism of the screws. All designs were evaluated and compared by 7 test users using integral projection X-rays calculated from the CT dataset. Results were checked using a 3D model of the bone, also calculated from the CT dataset. RESULTS: Positioning screws using the deformable model resulted in a significantly smaller distribution of screw tip locations and no penetrations into the hip joint, in contrast to the other approaches where up to 11% of screws were misplaced. CONCLUSIONS: Constraining the planning and navigation space by means of a deformable model allows better control of screw positioning and thus increases the chances of a successful intervention. In particular, CAS systems allowing for virtual fluoroscopy should consider supporting this planning approach.

[Adaptive planing model for osteosynthesis of femoral neck fracture]. / Untersuchung adaptiver Planungsmodelle zur Osteosynthese der Schenkelhalsfraktur.

To investigate how surgeons can be supported in planning of screws for femoral neck fracture fixation reducing incidents of misplaced screws, a system was developed which makes use of a deformable model to be adapted to the femoral head/neck. The accuracy and usability of the system was checked against planning support systems mimicking the conventional positioning of screws within bi-planar x-rays. All designs were evaluated and compared by N = 7 test user. Checking the rate of misplaced screws a) at the femoral neck yielded rates of 8% or up to 42%, b) at the femoral head yielded rates of 0% or up to 11% for model-based or conventional planning, respectively. It is thus suggested to constrain the planning and navigation space by means of deformable models of the bone.

Two-Stage Transformation Assay for Cigarette Smoke Condensates using Murine c3h-10t1/2 Fibroblasts.

We investigated whether the two-stage transformation assay can be applied in routine testing for promoter-like activity of cigarette smoke condensate (CSC) as an in vitro equivalent of an in vivo tumorigenicity assay (mouse skin painting). We adopted a published assay procedure (Frazelle et al., 1983a), using 3-methylcholanthrene (MCA, 0.37mumol/litre, 24hr treatment) as the initiator. Rigorously standardized experimental conditions, such as multiparameter-screened serum, one fixed subculture level, and a rigid preculturing schedule, were employed. Transformation was expressed as the fraction of dishes containing type II and type III foci. Compared to the positive control, 12-O-tetradecanoyl-phorbol-13-acetate (TPA), transformation responses to CSC (three CSC batches that had different in vivo activity) were lower. Variations in dose-response relationships did not allow distinction between two of the three CSC batches, even with data pooled from seven assay repetitions over 2 years. In a second approach, to enhance the assay resolution, that is, the signal-to-noise ratio, promoter treatment twice per week was ineffective: the response and the background were both increased. Lowering the initiator concentration (0.08mumol/litre) enhanced the signal-to-noise ratio for TPA, but not for CSC. Even after standardization and enhancement of sensitivity, the two-stage transformation assay is useful primarily for qualitative assessment of promoter-like activity of weak promoters, such as CSC, rather than for quantitative comparisons.

Tobacco smoke-induced alterations of cytokeratin expression in the rat nasal activity cavity following chronic inhalation of room-aged sidestream smoke.

In a 12-month inhalation study on rats using room-aged sidestream smoke (RASS, 12 microg total particulate matter (TPM)/l) as an experimental surrogate for environmental tobacco smoke (ETS), we investigated differentiation changes, i.e. altered cytokeratin (CK) expression, in the epithelial lining at nasal cavity level 1 (NL1) (anterior portion of nasal cavity), and their correlation with histomorphological changes. In addition to conventional histopathological examination, routine paraffin sections were immunohistologically stained for various rat CK and evaluated. Changes in CK expression were observed in the nonciliated respiratory epithelium of maxilloturbinate, lateral wall, and nasoturbinate: in basal cells, increase of CK14 and CK18 and decrease of CK15; in nonciliated columnar cells, increase of CK15 and CK19. These CK changes had histomorphological correlates, i.e. reserve cell hyperplasia and squamous metaplasia. CK expression changes were also seen at sites without histomorphological changes, e.g. enhanced expression of CK14, CK18 in ciliated cells at the dorsal meatus, and CK15 at the septum. Most of the CK expression changes seen after 1 year of RASS exposure resembled the changes previously seen after 8 days of exposure.

Cytokeratin expression patterns in the rat respiratory tract as markers of epithelial differentiation in inhalation toxicology. II. Changes in cytokeratin expression patterns following 8-day exposure to room-aged cigarette sidestream smoke.

The expression of specific cytokeratin (CK) polypeptide patterns is a sensitive marker of the cytoskeletal differentiation of epithelial cells. We developed an immunohistochemical method to assess CK expression patterns in the rat respiratory tract using serial paraffin-embedded sections from the nasal cavity, trachea, and lung. In the present study, this method was used to detect exposure-related differences in CK expression patterns in adult Wistar rats following inhalation of room-aged sidestream smoke (11 mg total particulate matter/m3 air, 8 days, 12 hr/day, whole body). In the anterior nasal cavity level 1 (NL1), changes in CK expression patterns were observed in the respiratory epithelium of the lateral wall and the maxilloturbinate (CK14, CK15, and CK18) and in the squamous epithelium of the ventral meatus (CK13). At nasal cavity level 2 (NL2), immediately behind NL1, changes were observed in the olfactory epithelium (CK13, CK14, and CK18) and in the respiratory epithelium of the septum (CK7 and CK19), the lateral wall (CK7 and CK13), and the lateral aspect of the maxilloturbinate (CK14). Changes were also observed in the submucosal glands, nasolacrimal duct, and vomeronasal organ. In the trachea only CK7 expression changed, and in the lung expression of CK7 (bronchioli) and CK8 (bronchus) changed; the expression of other CK polypeptides did not change. The observed changes in CK expression at NL1 correlated with the histomorphological changes, whereas CK expression changes were also seen in the olfactory and respiratory epithelia at NL2 and in the trachea and lung, where no histomorphological changes were seen. These findings indicate that changes in CK expression in respiratory tract epithelial cells are a sensitive marker for cellular stress response.

Cytokeratin expression patterns in the rat respiratory tract as markers of epithelial differentiation in inhalation toxicology. I. Determination of normal cytokeratin expression patterns in nose, larynx, trachea, and lung.

Cytokeratin (CK) polypeptides constitute the intermediate filament cytoskeleton of epithelial cells. The patterns of CK expression can be regarded as specific markers for the epithelial differentiation status. Our objective was to map the cell type-specific CK expression patterns at all representative sites of the respiratory tract of untreated rats to use as a base for the detection of inhalation exposure-related differentiation changes. Using routine paraffin-embedded sections and a panel of well-characterized monoclonal antibodies for immunohistochemistry, we obtained CK staining patterns as follows. Nasal cavity: respiratory epithelium CK18, CK19 (basal, ciliated, nonciliated cells), CK14, and/or CK15 (basal and nonciliated cells); olfactory epithelium CK18 (basal, mid, apical zones and Bowman's glands), CK14, and CK15 (basal zone); squamous epithelium of ventral meatus CK14, CK15 (basal and suprabasal cells), CK1, 10/11, and CK13 (suprabasal cells); glands and columnar epithelia of vomeronasal organ and nasolacrimal duct CK7 and CK13 in addition to respiratory epithelial CK pattern. Trachea: similar to nasal respiratory epithelium with pronounced CK15 and additional CK7. Larynx: CK14, CK15 (basal, ciliated, nonciliated cells), CK8, CK18, CK19 (not in basal cells), CK4, and CK13 (cuboidal and squamoid cells of ventral half). Lung: bronchial epithelium CK14 and CK15 (basal cells only); bronchial and alveolar epithelium CK7, CK8, CK18, and CK19; bronchiolar epithelium similar but less CK8 and no CK7; pleural mesothelium CK7, CK8, and CK19. This inventory of complex CK expression patterns provides the basis for investigating test substance-related effects in inhalation toxicology, e.g., cigarette smoke-induced changes.

Cytokeratin patterns of epithelial cells of the rat nasal cavity in vivo and in vitro.

Nasal epithelial cells are a primary target for the actions of inhaled substances. To enable the determination of alterations in cell differentiation in the rat inhalation model, we developed a methodology to assess cytokeratin expression in rat nasal tissue. A panel of commercially available antibodies was validated for specificity to defined rat cytokeratins by immunoblotting. The development of immunohistological procedures to enhance spatial resolution enabled mapping of cytokeratin patterns in various cell types at defined regions and levels of the rat nasal cavity using serial sections and a standardized evaluation schedule.

Signals required for differentiating dendritic cells from human monocytes in vitro.

Human peripheral blood monocytes (Mo) can quantitatively be differentiated into potent accessory cells which exhibit dendritic cell (DC) function and phenotype. This alternative differentiation of Mo into DC rather than into macrophages (M phi) will be triggered when signals leading to M phi differentiation are omitted from the culture. Serum contains such stimulatory signals and was therefore omitted from the cultures. The cells were cultured on solid agarose surfaces. This newly developed technique allows for the attachment-free differentiation of DC. In the absence of signals, Mo do not survive in culture. IL-1 and IL-6 are endogenously produced by Mo and create an autokrine stimulatory milieu which increases the accessory function. However, also mature Mph will respond by an increased accessory activity upon stimulation by these cytokines. Cyclic AMP is the most likely second messenger to trigger an increase in accessory activity. IL-4 plus GM-CSF further act to upregulate dendritic cell properties and function. By action of these mediators, virtually all markers and functions of Mo/M phi are lost, and the cells convert to the phenotype and function of dendritic cells.

Expression of CD54, CD58, CD14, and HLA-DR on macrophages and macrophage-derived accessory cells and their accessory capacity.

Human peripheral monocytes can differentiate in vitro into macrophages (Mph) possessing a low accessory activity in T cell stimulation. Mph can be converted into a state of high accessory activity by treatment with dibutyryl cyclic AMP. This finding was used in this study to achieve Mph-derived AC (MphAC). Among the surface antigens on AC which have been shown to participate in accessory events leading to T cell proliferation, MHC class II antigens, CD58 (LFA-3) and CD54 (ICAM-1) seem to be especially important. We show here that the high accessory capacity of MphAC was not correlated with a high level of the surface antigens HLA-DR, CD58, and CD54. The amount of CD54 molecules was, in fact, lower on the MphAC than on the Mph.

IL-4 decreases the expression of the monocyte differentiation marker CD14, paralleled by an increasing accessory potency.

IL-4 has been found to affect the phenotype and a variety of functions of human monocytes and macrophages and has been discussed as a monocyte activating protein along with other cytokines, such as IL-1 and IL-6. In this study we compared the effects of the cytokines IL-1, IL-6, IL-4, and a combination of IL-1 and IL-6 on the expression of the CD14 antigen, the FcIIIg receptor molecule CD16 and the MHC-class II molecules HLA-DR and HLA-DP. These molecules represent characteristic monocyte surface markers. Furthermore, the CD14 molecule has been described as a surface antigen of high in vivo relevance representing an indirect receptor for LPS. We further analyzed the effect of IL-4 on monocytes and macrophages with respect to their accessory function to initiate T-lymphocyte proliferation. Human peripheral blood monocytes strongly express the antigen CD14 and maintain it as a stable surface molecule during their differentiation to macrophages. Flow cytometry analysis of cultured monocytes demonstrated that cells incubated in the presence of IL-4, but not IL-1 and/or IL-6 revealed a reduced expression of the CD14 antigen in a dose- and time-dependent manner. After 3 days IL-4 treated cells were virtually CD14-negative. At the same time the expression of the CD16 antigen (FcRIIIg) was also strongly reduced, whereas the treatment with IL-4 led to an increased expression of MHC class II antigens such as HLA-DR and HLA-DP. The spontaneous low expression of HLA-DQ antigen on monocytes was not affected by any of the cytokines. Functionally, IL-4 treated CD14-negative monocytes exhibited a more than 2-fold higher activity to stimulate an accessory cell-dependent T cell proliferation. This was found in a mitogenic assay and in MLC when compared to monocytes cultured in the absence of IL-4. These observations provide further evidence that IL-4 is a major modulator of monocyte surface antigen expression. Moreover, IL-4 has an enhancer-effect on monocytes as accessory cells and therefore may be of considerable importance as a regulatory factor during monocyte development to accessory cells. Inasmuch as the CD14 molecule functions as a receptor for LPS-binding protein, our results suggest that IL-4 might also play an important regulatory role in processes initiated by bacterial lipopolysaccharides during inflammation and sepsis.

Veiled accessory cells deduced from monocytes.

Human peripheral blood monocytes were cultured under conditions which prevent macrophage development. Media containing selected charges of fetal calf serum as well as a number of serum-free and protein-free media were found to convert monocytes into homogenous populations of loosely adherent veiled cells. After one week of culture, these cells developed dendritiform elongations. Functionally, these cells acquired an increased capability of serving as accessory cells in T lymphocyte mitogenic stimulation. Phenotypically, they were strongly reduced in macrophage markers such as nonspecific esterase, phagocytosis and Fc-receptors. The majority of the population was even negative for these markers. It thus appears that highly active accessory cells, which closely approach the phenotype of lymphoid dendritic cells, could be deduced from monocytes. These accessory cells could be maintained in culture for several weeks without proliferation and without converting to macrophages. They could further be induced to differentiate to macrophages by an activity present in human serum. Ontogenetically, the accessory state as described here is a differentiation stage preceding macrophage differentiation. When macrophages differentiate from monocytes, they have to pass the transient stage of increased accessory activity.

On the stimulation of gluconeogenesis by L-lysine in isolated rat kidney cortex tubules.

UNLABELLED: 1. L-Lysins (2 mM) stimulates (30-50%) gluconeogenesis in isolated kidney cortex tubules from 24-h-starved rats in the presence of lactate and Krebs cycle intermediates, but not pyruvate and glutamate. The stimulation of renal gluconeogenesis by L-lysine is a short-term effect. The effect is of catalytic nature, but not due to sparing of substrate. L-lysine caused a decrease of lactate/pyruvate ratio. 2. Apart from L-lysine, 1-10 mM NH-4Cl (16-40%) and 2 mM aspartate (66%) were capable to stimulate gluconeogenesis from lactate. Other amino acids tested did not stimulate renal gluconeogenesis, except L-alanine. The stimulation of gluconeogenesis by lysine was not additive to the stimulation by NH-4Cl. Likewise, there was no stimulation of gluconeogenesis from lactate by L-lysine in the presence of glutamate or arnithine. Levels of ammonia, glutamate and aspartate were elevated in the presence of L-lysine, NH-4Cl or glutamate about two-fold, were capable to stimulate gluconeogenesis. 3. The stimulation of gluconeogenesis by L-lysine from malate, succinate and oxoglutarate was abolished in the presence of amino oxy-acetate (0.05 mM), whereas controls were not significantly affected. 4. After 1 h of incubation about 5% of added [U-14C] lysine was recovered as 14-CO-2. The extra ammonia formed in the presence of L-lysine would also correspond with about 5-10% of added lysine being metabolized. 5. 14-CO-2 formation from [1-14C] butyrate and [1-14C] palmitate was inhibited by 20-30% in the presence of 2 mM L-lysine. 6. O-2 uptake and cellular levels of K+ were not significantly affected by L-lysine. 14-CO-2 fixation from pyruvate and 14-CO-2 formation from [1-14C]-pyruvate by isolated, intact rat liver mitochondria remained unchanged by L-lysine. Likewise no direct effect of L-lysine on enzyme activities could be detected. 7. CONCLUSION: The data seem compatible with the assumption that stimulation of gluconeogenesis in isolated kidney cortex tubules by L-lysine is due to a stimulation of the malate-aspartate shuttle as a consequence of an increased provision of glutamate and aspartate.

Stimulation of renal gluconeogenesis by L-alanine and AIB.

L-alanine as well as AIB have been shown to stimulate gluconeogenesis in isolated kidney cortex tubules in a catalytic way. The data reported are consistent with the view, that the stimulation of renal gluconeogenesis by L-alanine and AIB is due to an inhibition of glycolysis at the level of the pyruvate kinase reaction. In the light of results of Carminatti et al. [8], showing that in kidney cortex 70-80% of total pyruvate kinase activity is represented by a type which is insensitive to inhibition by ATP but sensitive to inhibition by alanine, it appears conceivable also from our results, that alanine counteracted by FDP might contribute to the regulation of pyruvate kinase acti-ity and consequently thereby gluconeogenesis in kidney cortex.