Biomedical subjects

A Wichelhaus

Publications and source records attributed to A Wichelhaus.

18 recordsLinked to original sources

PubMed2000

Quantitation of Helicobacter pylori in dental plaque samples by competitive polymerase chain reaction.

AIM: To establish a competitive PCR (cPCR) assay for quantitation of H pylori organisms in dental plaque samples. METHODS: The cPCR co-amplified target H pylori DNA and a known amount of internal standard template in the same tube with the same primers directed to 0.86 kb DNA of H pylori. The internal standard was a synthesised DNA bearing the same primer recognition sites at two ends and a non-homologous core sequence as the target DNA fragment. Quantitation was based on determination of the relative, not absolute, amounts of the differently sized and [32P]-dCTP labelled products derived from H pylori DNA and the competitive internal standard after gel electrophoresis separation. RESULTS: A significant correlation between known amounts of H pylori added to dental plaque samples and the results of the cPCR was found, and a standard line was developed which allowed quantitation of H pylori in the plaque samples. cPCR was performed on supragingival plaque samples from 10 adult patients with H pylori infection in the stomach, and from five adults and six children without H pylori infection in the stomach. The ranges of H pylori numbers were 1-213 (median 25), 6-76 (10), and 4-94 (14) cells/mg of dental plaque in the three groups, respectively. CONCLUSIONS: cPCR is useful for quantitation of H pylori in supragingival dental plaque samples; however, the number of the organisms in dental plaque samples seems very low.

Adolescent↗

PubMed1998

The influence of the spring activator on the mobility of the lower jaw in traumatically injured patients.

For functional rehabilitation and improvement of mandibular mobility, 14 patients with dislocated collum or collum fracture dislocations were treated with a spring activator after surgical-conservative treatment. With an interincisal distance of < 12 mm, therapy was started with a loop spring. The average age of the patients was 26.6 years. Eight patients showed additional traumatic injuries, 2 patients were seriously polytraumatically injured. The clinical investigations referring to the maximum mouth opening and maximal interincisal distance resulted in a good to very good functional rehabilitation in all cases. The average maximal interincisal distance of 31.7 mm at the beginning of the spring activator therapy could be increased to 47.3 mm. The largest increase of the maximal interincisal distance was observed after 4 weeks of therapy. The type of reaction, however, differed interindividually. Three patients showed a spontaneous improvement of the interincisal distance within the first 2 to 3 weeks of removal of intermaxillary fixation, whereas 7 patients showed no improvement or only slightly improved values until insertion of the spring activator. An enlargement of the interincisal distance could be achieved in almost every patient within a relatively short period of time despite a drastically reduced mouth opening. Consequently, because of its mode of action in the form of a neuromuscular influence, the spring activator is especially suitable for the functional rehabilitation of patients with fractures of the condylar process.

Activator Appliances↗

PubMed1998

Root resorptions in upper first premolars after application of continuous intrusive forces. Intra-individual study.

A scanning electron microscopy study of possible root resorptions and their localization after application of continuous forces of different magnitudes was conducted. Twelve upper first premolars, indicated for extraction, were previously intruded with constant forces. The teeth were divided into 3 groups: 1. non-moved control teeth, 2. continuous force application of 50 cN for 4 weeks, 3. continuous force application of 100 cN for 4 weeks. Specially designed NiTi-SE-stainless steel springs were utilized to exert the actual forces. After experimental tooth movement, the extracted teeth were dehydrated, metal-coated and examined by scanning electron microscopy. The intruded teeth showed resorptive areas consisting of lacunae (concavities) in the mineralized root surface. The teeth moved with 50 cN showed in the apical third several, in the medial third few, and in the cervical third no resorptive areas. In the case of the teeth moved with 100 cN, we observed resorptive areas in most of the apical third--including the apex contour-, several in the medial third, and none in the cervical third. In the control group no resorptions were observed. Thus, our results suggest that intrusion of human teeth with continuous forces induces root resorption, depending on the magnitude of force applied.

Adolescent↗

PubMed1998

[Therapy of dislocated calcaneus joint fracture with the AO calcaneus plate].

From August 1992 to March 1997, 66 patients with 71 displaced intraarticular calcaneal fractures were prospectively examined after an operative treatment using an extended lateral approach and the ASIF calcaneal plate followed by early functional postoperative treatment (mean follow-up 25 months, retrieval rate 96%). To classify the type of fracture and to verify the results of reduction and of retention CT scans in the coronal and transverse plane were performed pre- and postoperatively and on the day of assessment. The Zwipp Score was used for clinical evaluation. After fractures with 5 to 8 points according to the calcaneal fracture scale, 97% of the patients had an anatomical or near anatomical reduction of the posterior facet and the clinical outcome in 82% of the patients was graded as good or excellent. In 70% of patients with a fracture rated 9 to 10 points a good reduction was demonstrated and clinically there were 67% good or excellent results. But in the fractures with 11 to 12 points, despite 40% good reductions, the clinical outcome was graded as good in 10% of the patients only. However, if the post-operative displacement of the posterior facet was more than 2 mm no patient had a good result independent of the type of fracture. Due to restoration of the geometry of the most comminuted fracture types and the immediate partial weight bearing secondary soft tissue problems could be minimized without any loss of articular reduction. Anatomical reduction and stable internal fixation together with adequate physical therapy are apparently preconditions but not a guarantee for a good clinical result after displaced calcaneal fractures.

Adult↗

PubMed1996

Intrusion mechanics according to Burstone with the NiTi-SE-steel uprighting spring.

Intrusion mechanics according to Burstone can be regarded as a practicable method for the intrusion of incisors. 1. By applying the NiTi-SE-steel uprighting spring, relatively constant forces can be exerted over a large range of intrusion on both sides of the anterior tooth archwire. 2. By bending a 150 degrees tip-back bend or a curvature into the steel portion, the uprighting spring presented here is brought into the plastic range of the characteristic curve of force. 3. Application of sliding hooks on the intrusion spring permits readjustment for force transfer onto the anterior archwire. 4. Connecting the anterior archwire with the posterior elements by means of a steel ligature can be recommended only in some cases, because sagittally directed forces may be produced. 5. The adult patients presented showed an average intrusion of 0.6 mm/month, if a linear connection was presupposed. 6. An intrusive effect on the incisors could first be detected clinically after 6 to 8 weeks. 7. Application of a torque-key proves especially useful in controlling the incisor position during intrusion in order to avoid unnecessary radiography. 8. Actual prediction of the centre of resistance with the help of a cephalometric radiograph proved not to be feasible. 9. The calculated maximal intrusion of the mandibular incisors was 7 mm. 10. The torque-segmented archwire with crimped hooks and pseudoelastic springs between the molars and the crimped hooks proved very effective for retrusion and intrusion of maxillary incisors. The maxillary anterior teeth can be retruded by a total of 7 mm without readjustment. 11. Constant moments and forces could be transferred by applying preformed arch wires and segmented arch wires.

Adult↗

PubMed1995

[Clinical experiences with the torque-segmented arch (TSA)].

The torque segmented archwire presented here led to a good torque transfer in all patients, however this transfer differed on a case by case basis. With regard to the angle 1-NA, the average monthly torque change was 2.34 degrees. The smallest torque transfer was 1 degree; the biggest 5.5 degrees per month. Because the torque segmented arch wires consist of a pseudoelastic material for the anterior teeth and a steel portion for the lateral teeth, the anterior component can be adapted to the patient's individual situation and in addition the lateral components make possible the bending of first, second and third order bends. The dimensions of the superelastic materials are 0.016 x 0.022, 0.017 x 0.025, and 0.018 x 0.025. In all 3 dimensions it is possible to select a torque of 30 degrees or 45 degrees. The use of such arch wires yields the following advantages: 1. Problem-free adaptation to the patient's individual situation. 2. Torque segmented arch wires can be applied in the case of the standard edgewise technique as well as in each case of the straight wire technique. 3. The practitioner is no longer dependent on the torque loss of the archwire and the individual axial position of the incisors. 4. With the help of the torque key it is possible at any time to control the already transferred torque with regard to the occlusal plane. 5. The torque segmented archwire can also be applied in the segmented archwire technique. 6. The torque segmented archwire with right angular or round lateral components is well suited for the retraction of the anterior area.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1995

[The dental and skeletal effects of the jumping-the-bite plate and high-pull headgear combination. A clinical study of treated patients].

While planning treatment of the 30 patients with a dental and skeletal class II anomaly on which this study is based, the primary treatment goals were correction of the dental and skeletal structures and attenuation of vertical growth by means of influencing the maxillary skeletal structures and the resultant mandibular reaction. The desired treatment results were achieved in all patients. Even so, however, the effects on individual patients in respect to skeletal influences were markedly different. It was especially helpful that during therapy simultaneously with exerting influence on the maxillary base plane, the influencing of the occlusal plane occurred in the same direction. Through the additional application of high-pull headgear, maxillary growth was clearly restrained and the inclination of the maxillary base plane inhibited. Even difficult skeletal discrepancies, sagittal as well as vertical, can be treated with the bite-jump appliance in combination with a high-pull headgear. This also makes it possible to achieve protrusive repositioning of the mandible in patients with a pronounced vertical growth pattern without causing on open bite. In retrospective the patients' treatment plans proved to be completely appropriate, however, the fact should not be overlooked that changing the occlusal plane is essential for the realization of a positive therapeutic result.

Activator Appliances↗

PubMed1995

[Biomechanical testing of the new torque-segmented arch (TSA)].

New torque-segmented arch wires are presented which consist of a superelastic anterior component with 30 degrees or 45 degrees torque and which are connected to 2 steel lateral components by means of a crimped connector. When using such torque-segmented arch wires, the crimped connector rests mesially to the canine bracket and the lateral components exhibit a torque of 0 degree. The use of the torque-segmented arch wires requires the practitioner to adjust the anterior tooth segment, to bend in first order bends in the steel lateral portion as well as to bend in a sweep to avoid an anterior tooth extrusion, and, if desired, to bend in third order bends to influence premolars and molars. In some cases the simultaneous application of palatal arches can become necessary, because each torque transfer results in a transversal enlargement in the molar area. Compared to conventional steel wires with dimensions of 0.016 x 0.022 in which an anterior tooth torque is bent, the torque segmented arch wires exhibit considerably fewer side effects, but there is a larger distally rotating moment for the molars. 1. When applying torque-segmented arch wires, the extrusive force transferred to the anterior teeth is considerably smaller. 2. The protrusive force acting on the anterior teeth is also considerably smaller, which results in a reduced demand being placed on the anchorage of the molars. 3. The torque transfer to the incisors rests in a quite moderate range, even in the case of a 50 degrees torque. For this reason, the practitioner can expect diminished or no resorptions at all compared to the aforementioned steel wires. 4. The Martensite plateau of the torque-segmented arch wires exhibit constant moments in large areas so that such arch wires can be used in almost every anterior tooth position. 5. The segmented wires presented here can be applied not only in the case of the standard edgewise technique but also in each case of the straight-wire technique. 6. These new arch wires require no readjustment of torque values. 7. To control the transferred torque values it is recommended that the already transferred torque values be monitored during each check-up with the help of the described torque key. 8. When the torque values of the brackets are known, the torque key renders frequent patient X-rays superfluous. 9. When the desired torque values are attained, treatment can proceed using conventional arch wires.

Biomechanical Phenomena↗

PubMed1995

[The development and testing of a new NiTi-SE-steel uprighting spring].

The uprighting spring presented here consists of a combination of superelastic material which is connected with a steel were by means of a crimped connector. Pseudo-elastic areas of such a spring can be used well by combining superelastic material with steel. The uprighting spring presented here yields the following advantages: 1. The uprighting moment of the molar is between 10 and 20 N with a 40 degree tipping of molar.2. The uprighting springs exhibit a large plateau in the area of 8 to 15 Nmm depending on a bending-in of an alpha-bend. 3. An intrusive force of approximately 0.5 to 1.0 N can be produced by varying the alpha-bend. The preformed uprighting spring in combination with a cross tube can be affixed without any problems, because only the alpha-activation must be bent in. 5. Practically, a reactivation during uprighting is not required. 6. An enlargement of the alpha-moment to produce an intrusive force makes great demands on the anchoring element. For this reason, one must check in each individual case, if an anchoring segment displays the required stability. 7. By lengthening the SE material at the crimped connector, the alpha and beta-moments become smaller, as does the intrusive (extrusive) force applied to molars.

Biomechanical Phenomena↗

PubMed1995

[The clinical use of the new NiTi-SE-steel uprighting spring].

In clinical practice the NiTi steel uprighting spring presented in this study has been employed up until now to upright 30 molars. The advantage of this spring is that in large areas the pseudoelastic part of the spring transfers constant moments and forces to the molars. In addition, the steel part makes it possible to simply and easily adjust and fasten alpha-bends. Because of the relatively small uprighting moments of 10 up a maximum of 25 Nmm such an uptighting spring can also be applied without any modifications in cases in which the molars are tipped up to 50 degrees. Going beyond this our study determined that it is possible to exert intrusive forces of 0.4 N over the entire uprighting area by bending-in an 45 degrees alpha-bend. From a 15 degrees tipping on up the uprighting moments applied to molars remain relatively constant and they are only dependent on the bent alpha-activation. An uprighting by intrusive force on the molars can also be achieved through an alpha-activation of 0 degree (90 degrees + 40 degrees), when the vertical length of the pegs is enlarged. An on average 1.43 mm per month root mesialization of the uprighting spring with the Memory Maker, should such for whatever reason be considered desirable, take place only in the final stage. In almost every case of molar uprighting it is possible to fasten a figure eight ligature from the molar to the cross tube. The uprighting spring presented here combined with a cross tube proves to be an effective method for achieving a fast and trouble free uprighting of molars.

Adolescent↗

PubMed1995

[How effective is asymmetrical headgear in practical use?].

The asymmetrical face bow with internal hinge was successfully employed in the treatment of all examined patients. It finds application as an individual appliance, in combination with removable appliances, and in conjunction with the fixed appliance technique. The major advantage of the face bow is that during a check-up visit, because it is already in place, it presents itself as a proven means for the treatment of asymmetries by adding a hinge on the side not to be distalized and by shortening the external arm on the same side. It is not necessary to employ a new, special face bow or even to change the orthodontic bands. In addition, in the case of an intermaxillary midline correction, no anchorage loss occurs. In the case of more extensive molar rotations, a pretreatment with a palatal archwire is recommended to rotate the molars. Because in 4% of the patients a cross bite or a cross bite tendency arises on the side distally treated, at the beginning of treatment the use of bands with attachments for palatal archwires should be considered. Relatively sizable distal forces in the range of 2:1 to 4:1 are exerted on the molar. This should be taken into account when selecting the forces of the external arm. It is recommended to apply on each of both sides a distal force of no more than 4 to 5 N. Decoupling of forces and movements through the internal hinge makes it possible for the practitioners to check the asymmetrical effect of the face bow by pulling out carefully the lingual archwire from the right or left tube. As long as the hinge still folds down, when the face bow is applied, the geometrics of the face bow should be altered. The following procedures can be recommended: 1. Further shortening of the already shortened arm; 2. outward bending of the long external arm; 3. use of an additional stop tube at the lingual archwire on the side that must be distalized. During the use of related low-pulls, the molars are subjected to diverse forces as a result of preferred sleeping positions, head bearings, and extensive friction, To avoid these non-calculable asymmetries, it is recommended to use gliding low-pulls. Because of the excellent results achieved throughout the use of the asymmetrical headgear with the lingual archwire, it can be recommended that it become a standard appliance in clinical practice.

Biomechanical Phenomena↗

PubMed1995

[Skeletal and dental changes during the use of the bite-jumping plate. A cephalometric comparison with an untreated Class-II group].

In this study 95 patients with a malocclusion type Angle class II were treated with a bite jumping appliance and the results achieved were compared with untreated class II patients. A clear improvement in the skeletal and dental relationships was observed. Significant changes were achieved yearly in the following: 1. the angle SNA was reduced (0.82 degrees), 2. the angle SNB was increased (0.57 degrees), 3. the angle ANB was reduced (1.39 degrees). All 3 of these variables are significant. Other skeletal variables, most notably the incline of the maxilla to the line NS, were not influenced nor was the relation of posterior facial height to anterior facial height. The mandibular incisors did not exhibit increased protrusion relative to the mandibular plane. Only the angle of the mandibular incisor to NB was changed by the total protrusion of the mandible. The maxillary incisors in these cases manifested obvious lingual tipping. For this reason the orthodontist must weigh carefully on an individual patient basis, whether the use of adjunctive torque springs is required and necessary.

Activator Appliances↗

PubMed1994

Photoaffinity labelling of cardiac membrane GTP-binding proteins in response to insulin.

Plasma membranes from rat cardiac ventricular tissue and insulin receptors partially purified by wheat-germ-agglutinin chromatography were subjected to direct photoaffinity labelling with [alpha-32P]GTP in order to elucidate the presence of insulin-receptor-coupled GTP-binding proteins. In plasma membranes three proteins have been identified that exhibit an enhanced photolabelling with the nucleotide in response to insulin. The apparent molecular masses of these proteins were found to be 56, 60 and 74 kDa. Photolabelling of partially purified insulin receptors showed the copurification of the 60-kDa species, whereas the 56-kDa and 74-kDa proteins could not be detected. Furthermore, the 60-kDa G-protein was found to be specifically co-immunoprecipitated with the insulin receptor. Incubation of insulin receptors with insulin increased the labelling of the 60-kDa band to 205 +/- 27% (n = 5) of control. Immuno- and ligand-blotting experiments revealed the additional presence of a 39-kDa G(o)-like protein and two G-proteins with molecular masses of 24 and 26 kDa in the receptor preparation. Under basal conditions the insulin receptor and the 60-kDa G-protein exhibited an apparent inverse distribution between plasma and microsomal membranes with the G-protein being extensively labelled in the microsomal fraction. In conclusion, our data show that, in its native environment, the cardiac insulin receptor couples to at least three GTP-binding proteins. Out of these, a 60-kDa species of microsomal origin, copurifies with the insulin receptor. It is suggested that this G-protein is associated with the insulin receptor and may be involved in insulin receptor signalling in target cells.

Affinity Labels↗

PubMed1994

[Can magnets or additional intermaxillary forces improve the mode of action of jumping-the-bite plates?].

The use of accessory intermaxillary elastic traction or magnets during bite jumping appliance therapy marks a significant improvement in patient treatment. The use of interarch traction results in 100% mouth closure during the night, which is independent of the patient's sleeping position. During the night the guide pegs are subjected to almost no stress, which guarantees a quick adaptation. Additional intermaxillary traction does call for anchoring procedures in the maxillary anterior (torque springs) and mandibular molar region (clasps). According to the dental situation, the application of dynamic force can be withdrawn for a transitory period of time. Use of additional magnets in the anterior, depending on sleeping position, leads to complete mouth closure in up to 70 to 90% of the cases. Extensive measures in the mandibular and maxillary anterior areas must be considered when using this variant. In many cases the application of brackets is an absolute necessity. However, when the dental situation calls for it, magnets cannot be deactivated. All magnets in use today corrode very easily. It is, therefore, recommended that magnets used interorally be especially well shielded. Leaky capsules must considered especially problematic. Correct adjustment in the sagittal plane does not in any case guarantee stabilization. Only when a 3- or 4-stage bite has been reached, can it be said that a good adjustment in the neuromuscular masticatory pattern has been achieved. Depending on patient compliance, this period can be significantly drawn out. A functional analysis is not a suitable method for analyzing an extant stable result. With both of these modifications there is a tendency to greater dentoalveolar effect and diminished influence on the skull. The issue of whether magnets have no place in orthodontics, as Gianelly [3] claims, cannot be definitively answered, however, it can be said that intermaxillary traction, especially when force is applied by using super-elastic springs, is less expensive, demonstrates a better effectiveness, and it is much easier to use.

Activator Appliances↗

PubMed1994

G protein expression and adenylate cyclase regulation in ventricular cardiomyocytes from STZ-diabetic rats.

Isolated adult ventricular cardiomyocytes have been used to study the effects of insulin-deficient diabetes on the expression of cardiac G protein alpha-subunits. Immunoblot analysis of plasma membranes revealed the presence of three different Gs proteins with molecular masses of 45, 47, and 52 kDa. Furthermore, cardiomyocytes were found to contain Gi-2 (41 kDa) and G(o) (39 kDa). Heart cells from streptozotocin-diabetic rats exhibited an unaltered expression of the Gs proteins, whereas Gi-2 and G(o) were reduced by 58 +/- 2 and 27 +/- 11%, respectively. In cells from diabetic rats, adenosine 3',5'-cyclic monophosphate (cAMP) accumulation in response to isoproterenol decreased by approximately 30% at agonist concentrations of 10(-7) to 10(-5) M, with an unaltered maximum stimulation by forskolin. Treatment of cardiomyocytes with pertussis toxin resulted in an incremental increase of isoproterenol-stimulated cAMP formation, which was significantly lower in cardiac myocytes from streptozotocin-diabetic animals (19.2 +/- 1.7 vs. 11.5 +/- 2.4 pmol cAMP.5 x 10(4) cells-1 times 10 min-1). The inhibition of the isoproterenol-induced cAMP accumulation by carbachol in the intact cell was not altered in streptozotocin-diabetes. In conclusion, our data show that insulin-deficient diabetes is associated with a reduced expression and concomitant functional loss of Gi in ventricular cardiomyocytes. Receptor-mediated inhibition of adenylate cyclase remains unaffected by this process, whereas the beta-adrenergic stimulatory pathway involves an additional defect upstream of the adenylate cyclase/G protein system.

Adenylyl Cyclases↗

PubMed1992

Contraction-induced translocation of the glucose transporter Glut4 in isolated ventricular cardiomyocytes.

Field stimulation of isolated adult ventricular cardiomyocytes was used to study the effect of contractile activity on 3-O-methylglucose transport and the subcellular distribution of Glut4. Cells contracting at a frequency of 1 Hz for 30 min exhibited unaltered basal and insulin-stimulated rates of glucose transport when compared to resting cells. However, at 5 Hz 3-O-methylglucose transport increased to 224% of control after 5 min. Under these conditions insulin was unable to produce a significant additional stimulation of glucose transport. Immunoblotting with an anti-Glut4 polyclonal antibody showed that both insulin and contraction (5 Hz) increased the amount of Glut4 in a plasma membrane fraction by about 8-fold with a parallel decrease in an intracellular membrane fraction by 60-65%. These data suggest the existence of an identical insulin- and contraction-recruitable Glut4 transporter pool in cardiomyocytes.

3-O-Methylglucose↗

PubMed1988

[Individual sensitivity of cilia. A simple in vitro test method].

A simple patient-related method is described that determines the effect of toxic substances on the ciliary activity of human nasal cilia cells. The method is suitable for investigating and numerically determining substance-specific toxicity and individual sensitivity even between patients of different states of health. This is illustrated by the example of two preservatives introduced in human medicine: chlorhexidine and merthiolate.

Chlorhexidine↗

PubMedDate not supplied

Surgical treatment of bone metastases in breast cancer.

Breast cancer is an osteotropic primary tumor. For the patient metastases to the skeleton imply functional restriction with immobility and pain. Unlike other primary carcinomas breast cancer shows a distinctly longer life expectancy after occurrence of skeletal filiae. LOTE even states a mean survival rate of 4 years. Impending or manifest pathologic fractures as well as pain refractory to medication therapy are indications for operative treatment. As a function of the estimated life expectancy, the number and localisation of metastases and possible adjuvant therapy (hormonal or chemotherapy, radiotherapy) the operative procedure must be chosen. Available options are' intramedullary stabilizing procedures, compound osteosynthesis or endoprothetic means. The objective is the restitution of the weight bearing capacity of the affected skeletal region in addition to pain reduction. This leads to early function and mobility and improves the patient's quality of life.

Bone Cements↗