[GTR--technique--preparations, methods and results].
Explore the source record for details and available documents.
Alveolar Bone Loss↗
Biomedical subjects
A Zimmermann
Publications and source records attributed to A Zimmermann.
Diversity in motile responses of human neutrophil granulocytes: functional meaning and cytoskeletal basis.
Different agonists induce motility and shape changes, but only a specific polarized shape is correlated with directed migration. An intact and dynamic actin network appears to be important for motility and migration. Motility is usually associated with an increased level of F-actin, and a specific location of F-actin into surface protrusions. For locomotion, a specific location of F-actin, rather than a large net increase in F-actin appears to be of importance. Three major groups of responses can be distinguished on the basis of the type of shape changes, functional activity and organization of F-actin. 1. Agents capable of polarizing cells, such as chemotactic peptides, and microtubule-disassembling agents elicit, at appropriate concentrations, a marked chemokinetic response, but little if any fluid pinocytosis. F-actin shows a polar location, being concentrated mainly in the protrusions at the leading front. Chemotactic peptide also induces an increase in the level of F-actin and cytoskeleton-associated actin. It is, however, not clear if front-tail polarity and locomotion, induced by chemotactic peptide after longer time of stimulation, correlate with an actual increase in the level of cytoskeleton-associated actin. 2. Activators of protein kinase C such as PMA and diacylglycerols, induce nonpolar cells with surface projections. PMA and diacylglycerols stimulate pinocytosis substantially. All three agents tend to inhibit locomotion or chemotaxis as an immediate response. They also increase the percentage of cytoskeletal actin, and induce an enrichment of F-actin in surface projections. 3. Circus movement may occur in response to D20. These cells show little or no stimulation of locomotion or pinocytosis. Thus the functional significance of this motor response remains to be elucidated. We conclude that different agonists can induce motility and shape changes, but not necessarily chemotaxis. Only a polarized shape is correlated with directed locomotion. An intact and dynamic actin network appears to be important for motility including locomotion. Motility is usually associated with an increased level of F-actin, and a specific location of F-actin into surface protrusions. The actin-associated proteins alpha-Actinin, myosin and actin-binding protein appear also to be important for pseudopod formation. For locomotion, a specific location of F-actin, rather than a large net increase in F-actin may be of importance.
Actins↗
Crohn disease with sclerosing cholangitis and liver cirrhosis in adolescence.
A 17-year-old patient suffering from Crohn disease (CD) and liver cirrhosis is presented. At an advanced stage of the disease, he died of a concomitant urosepsis. Autopsy showed that the liver cirrhosis was caused by sclerosing cholangitis. This very rare complication of CD in adolescence is discussed.
Adolescent↗
90Y-resin particles--animal experiments on pigs with regard to the introduction of superselective embolization therapy.
Resin particles (diameter 45-75 microns) were labelled with 90Y, suspended in a glucose/dextran solution and infused into the kidneys of 3-month-old pigs (tumour model). Both kidneys of each animal were embolized with particles, but only one with active (90Y loaded) particles and the other, for comparison, with inactive particles. The organ measurements showed less than 1% of injected activity in bone, bone marrow, liver and lung compared to greater than 99% retention by the kidneys. Only minimal shunted activity was found in blood (less than 0.27%) and urine (less than 0.07%). There was a clear shrinkage of the 90Y-treated kidneys with a reduction in weight of up to 50%. Histologically, the ischaemic lesions (infarcts and atrophy) were clearly more pronounced and extensive in the 90Y-embolized kidneys than in the non-radioactive embolized kidneys. Furthermore, severe arterial wall changes and fibrotic necrosis due to radiation damage were observed in the 90Y-treated kidneys. It is concluded that with intra-arterially applied particles a dose of about 100 Gy is sufficient to completely destroy tissue-specific structures. Complications due to acute necrosis or inflammatory reactions were not observed, and there were no shunt related alterations seen in the liver or lungs. The 90Y-loaded resin particles are considered suitable for a super selective intra-arterial radioembolization.
Anesthesia↗
Glucose starvation and acidosis: effect on experimental metastatic potential, DNA content and MTX resistance of murine tumour cells.
Exposure to oxygen deprivation in vitro has been reported to cause drug resistance in CHO cells (Rice et al., 1986; PNAS 83, 5978) and enhancement of experimental metastatic (colonisation) ability of murine tumour cells (Young et al., 1988; PNAS 85, 9533). Both these studies also demonstrated the induction of a subpopulation of cells with excess DNA content. Since the micromilieu in tumours results in exposure of the tumour cells to conditions of acid pH and nutrient deprivation, as well as hypoxia, we have examined the effect of exposure to acidosis (pH 6.5) and glucose starvation on drug resistance, cellular DNA content and the experimental metastatic ability of KHT sarcoma and B16F1 melanoma cells. Cells were exposed to these conditions for 24 and 48 h and tested for resistance to methotrexate (MTX) or experimental metastatic ability either immediately following these exposures or after 24 or 48 h of recovery in normal growth medium. Both cell lines demonstrated an enhancement of colonisation potential, which was most marked when cells were injected after 48 h of exposure followed by a 24 or 48 h recovery period. Flow cytometric analysis demonstrated an increase in the fraction of KHT cells with excess DNA following both glucose starvation and acidosis we observed only a small increase in MTX resistance following acidic exposure of cells and no change following glucose starvation. Since both acidosis and glucose starvation are known to induce glucose regulated proteins (grp), a subset of the stress protein family, we studied the effect of treatment with another known inducer, 2-deoxyglucose. We found that this agent affected the metastatic efficiency of KHT cells in a manner similar to that observed following exposure to glucose starvation and acidosis. However, further studies are required to establish what role, if any, grp play in this effect. In conclusion this study shows that transient exposure of murine tumour cells to an acidic or glucose deprived environment can cause progression in terms of metastatic potential.
Acidosis↗
Anaerobic growth and cyanide synthesis of Pseudomonas aeruginosa depend on anr, a regulatory gene homologous with fnr of Escherichia coli.
Anaerobic growth of Pseudomonas aeruginosa on nitrate or arginine requires the anr gene, which codes for a positive control element (ANR) capable of functionally complementing an fnr mutation in Escherichia coli. The anr gene was sequenced; it showed 51% identity with the fnr gene at the amino acid sequence level. Four cysteine residues known to be essential in the FNR protein are conserved in ANR. The anr gene product (deduced Mr 27,129) was visualized by the maxicell method and migrated like a 32 kDa protein in gel electrophoresis under denaturing conditions. An anr mutant of P. aeruginosa constructed by gene replacement was defective in nitrate respiration, arginine deiminase activity, and hydrogen cyanide biosynthesis, underscoring the diverse metabolic functions of ANR during oxygen limitation. Pseudomonas fluorescens, Pseudomonas putida, Pseudomonas syringae, and Pseudomonas mendocina all had a functional analogue of ANR, indicating that similar anaerobic control mechanisms exist in these bacteria.
Amino Acid Sequence↗
Anaerobic regulation of transcription initiation in the arcDABC operon of Pseudomonas aeruginosa.
The arcDABC operon of Pseudomonas aeruginosa encodes the enzymes of the arginine deiminase pathway, which is inducible under conditions of oxygen limitation and serves to generate ATP from arginine. The 5' end of arc mRNA extracted from anaerobically grown cells was determined by S1 and primer extension mapping. The transcription initiation site was located upstream of the arcD gene and 41.5 bp downstream of the center of the sequence TTGAC....ATCAG. This sequence, termed the ANR box, is similar to the consensus FNR recognition site of Escherichia coli. Transcription of the arc operon in P. aeruginosa was strongly decreased by a deletion of the TTGAC half site or by a mutation in the anr gene, which is known to code for the FNR-like regulatory protein ANR. During a transition from aerobic to anaerobic growth conditions, the concentrations of arc mRNAs and the levels of the ArcD and ArcA proteins rose in a parallel fashion. Mutational analysis of the arc promoter region led to the conclusion that the distance between the ANR box and the -10 promoter region is important for promoter strength, whereas the -35 region does not appear to be critical for arc promoter function. These findings and previous results indicate that anaerobic induction of the arc operon occurs at the level of transcription and requires the ANR box in cis and the ANR protein in trans.
Amino Acid Sequence↗
Positive FNR-like control of anaerobic arginine degradation and nitrate respiration in Pseudomonas aeruginosa.
A mutant of Pseudomonas aeruginosa was characterized which could not grow anaerobically with nitrate as the terminal electron acceptor or with arginine as the sole energy source. In this anr mutant, nitrate reductase and arginine deiminase were not induced by oxygen limitation. The anr mutation was mapped in the 60-min region of the P. aeruginosa chromosome. A 1.3-kb chromosomal fragment from P. aeruginosa complemented the anr mutation and also restored anaerobic growth of an Escherichia coli fnr deletion mutant on nitrate medium, indicating that the 1.3-kb fragment specifies an FNR-like regulatory protein. The arcDABC operon, which encodes the arginine deiminase pathway enzymes of P. aeruginosa, was rendered virtually noninducible by a deletion or an insertion in the -40 region of the arc promoter. This -40 sequence (TTGAC....ATCAG) strongly resembled the consensus FNR-binding site (TTGAT....ATCAA) of E. coli. The cloned arc operon was expressed at low levels in E. coli; nevertheless, some FNR-dependent anaerobic induction could be observed. An FNR-dependent E. coli promoter containing the consensus FNR-binding site was expressed well in P. aeruginosa and was regulated by oxygen limitation. These findings suggest that P. aeruginosa and E. coli have similar mechanisms of anaerobic control.
Anaerobiosis↗
Chronic rejection and extrahepatic biliary tract obstruction 8 years after orthotopic liver transplantation using the gallbladder-conduit technique.
A case of delayed biliary obstruction and cholangitis, occurring in the setting of chronic allograft rejection, 8 years after liver transplantation using the gallbladder-conduit, is presented. Extrahepatic biliary obstruction may be seen in the late follow-up of liver grafting and rejection phenomena may play a significant role in the development of such obstruction.
Adult↗
Autoimmune adrenalitis, asthma and membranoproliferative glomerulonephritis.
We report the first case of membranoproliferative glomerulonephritis in a patient with chronic adrenal insufficiency due to autoimmune adrenalitis. In addition, this patient developed extrinsic asthma. The pathogenic implications of autoimmune adrenalitis with a long lasting hypocortisolemic state and the appearance of immunologically mediated diseases are discussed.
Addison Disease↗
Fluctuation of anti-A and anti-B histo-blood-group antibodies in a patient after liver transplantation.
The concentrations of anti-A and anti-B IgM and IgG antibodies have been studied in the serum of a patient with blood group AB who received a type A donor liver. A newly developed ABO-ELISA was used for this purpose and the values were compared to hemagglutination titers. During the postoperative study period over 8 weeks, the anti-A and anti-B levels showed a higher fluctuation than was measured in preoperative samples. Thus, in this AB-type patient, anti-A IgM varied 10-fold, anti-A IgG 20-fold and anti-B IgG 16-fold. Peak values corresponded to rejection episodes. Immunoactivation in the patient was further documented by the presence of abnormally high levels of soluble interleukin-2 receptors (sIL-2R) in serum samples. The study shows that monitoring of anti-A/B antibodies may represent a further criterion to follow-up transplanted patients during the critical postoperative graft acceptance period.
ABO Blood-Group System↗
[Transplantation of a bone with muscle pedicle in a case of pathological fracture of the femur neck].
Authors performed an operation for danger of fracture in case of extensive cystic fibrous dysplasia, localized in the femoral neck. The cyst was filled after refreshing its walls, with cancellous bone. To increase ossification a cortico-spongious bone cube, gained from the trochanter major and with retained connection with the insertion of the anterior third of the medial gluteus muscle was inserted in the area filled. The transplanted bone was fixed with an autologous fibular graft. Half a year after the operation bony transformation and good functional result could be observed.
Adult↗
[Gingivectomy].
The gingivectomy is the oldest surgical approach in periodontal therapy. During the centuries, the technique has been modified. Just at the middle of our century, gingivectomy was the most important surgical method in periodontal treatment. Indication for performance of the gingivectomy is the complete elimination of the periodontal pocket (gingival overgrowth/e.g. hyperplasia, subgingival caries, subgingivally located crown margins. The physiologic design of the free gingival margin by surgical means, gingivoplasty, must be taken under consideration. Depending on the long and painful healing for the patient, gingivectomy should be preserved for the indications above. Wherever possible, is recommended a flap procedure like the apically repositioned flap.
Anesthesia, Dental↗
[Preliminary results in periodontal treatment with guided tissue regeneration].
The objective of the present clinical study was to evaluate the predictability of a treatment procedure (GTR) aimed at regenerating periodontal tissue. 34 patients and 103 teeth were selected for the investigation. All teeth included in the study exhibited advanced loss of periodontal attachment. The periodontal defects were associated with even and/or angular bone defects or, in the case of multirooted teeth, advanced loss of periodontal tissue support in the furcation area. The probing bone level (PBL) and the probing tissue level (PTL) of the diseased sites were recorded using a standardized procedure. Treatment included placement of a barrier membrane (e-PTFE, Gore-Tex) according to the GTR method. After a healing period of 4-6 weeks the membrane was removed in a second surgical procedure. The result of healing was evaluated immediately after membrane removal. A further measurement was carried out during a re-entry operation 9 months later. The measurements of the treated sites revealed that GTR therapy had resulted in a marked tissue gain of more than 60% (p less than 0.001). In 33 of a total of 34 furcation-involved molars treatment had resulted in complete closure of the furcation defect. In the light of the findings of the present clinical trial it may be suggested that GTR therapy is an effective and predictable means of improving prognosis for both single- and multirooted teeth. A definite evaluation, of course, will be possible with the results of the re-entry procedure.
Adult↗
[New methods for determining surface hardness of dental materials].
Explore the source record for details and available documents.
Dental Materials↗
[Glossary of basic definitions for dental practice].
Explore the source record for details and available documents.
Suture Techniques↗
[Glossary of basic definitions for dental practice. Use of clinical indexes in daily dental practice].
Explore the source record for details and available documents.
Dental Plaque Index↗
[The etiopathogenesis of periodontal diseases: the role of microorganisms. A review].
The microbiology of periodontal diseases as well as associations between certain microorganisms and types/stages of periodontal diseases are discussed and the ecology and the composition of the subgingival plaque are included in this discussion, too. Furthermore, the possible role of microorganisms associated with periodontal diseases, their pathogenic mechanisms and their virulence factors are treated in the present article. Periodic upsets of the host-parasite equilibrium seem to be responsible for the bursts of disease progression. Several plaque hypotheses (specific, non-specific, opportunistic) have been proposed as likely models to explain the nature of periodontal infections and diseases. However, none of these theories is widely accepted at the moment. Therefore, we suggest that further investigations concerning the complex bacterial interactions and the manner in which the host responds to the mass and the composition of the dental plaque must be carried out in the future.
Adolescent↗