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Biomedical subjects

B Zimmer

Publications and source records attributed to B Zimmer.

At least 55 records · Page 3Linked to original sources
PubMed1990

[Scanning electron microscopic research on the clinical use of interdental stripping].

The morphology of approximal enamel that has been stripped for therapeutic reasons was evaluated under the scanning electron microscope (SEM) twelve weeks and one year after treatment. In part one of the study the teeth were extracted before evaluation, in the second part replica were taken. For comparative reasons the morphology of the natural approximal enamel surface was evaluated under the SEM, too. After twelve weeks the edges of the furrows were seen to be smoother and plaque accumulations were found in the depths of the furrows. One year after there was found essentially no difference. In some of the specimens there was found a certain levelling of the edges in the approximal contact area, but not in the cervical region of the artificially abraded tooth surface. The natural enamel surface of the contact area showed excavations of similar size as the furrows that remain after stripping and finishing. But our study shows that the therapeutic approximal abrasion leaves furrows in the cervical region that even after one year had not undergone repair. The question is discussed, if thus predispositions for periodontal pathologies and caries could be created.

Bicuspid↗
PubMed1990

[Changes in the functional status of the stomatognathic system due to orthodontic multiband treatment in the adult].

Ten patients who undergo an orthodontic therapy with a full-band modified straight-wire-appliance were examined clinically and by means of an electronic axiographic device (SAS-system) at the beginning of treatment and after an average of 12.6 months, respectively. While the clinical functional status showed only minor changes, alterations of all examined axiographic parameters could be detected. This finding reemphasizes the necessity of modern axiographic means to get additional information about the functional status of the TMJ. The alterations point to a shift in the functional pattern of articular and muscular components during orthodontic treatment. In the majority of cases, axiographic parameters remained constant, however. In that respect, it might be of special interest that even uncoordinated tracings, mainly in the horizontal plane, kept up its characteristic appearance. These findings show clearly, that alterations of occlusal relationships must not influence articular functional patterns immediately.

Adult↗
PubMed1990

Purification and amino-terminal sequence analysis of the complement-fixing and precipitin antigens from Coccidioides immitis.

Two proteins (21 and 48 kilodaltons) purified from endospore-spherule culture filtrates of Coccidioides immitis are identified as precipitin and complement-fixing antigens, respectively. To allow specific structural comparison to antigens identified by other investigators and as a first step to eventual serodiagnostic antigen production by recombinant DNA technology, amino-terminal amino acid sequences were determined for these antigens.

Amino Acid Sequence↗
PubMed1990

The Charles Bonnet syndrome. Visual perceptive dysfunction in sensory deprivation.

We present a series of four patients with the Charles Bonnet syndrome, which is characterized by recurrent vivid visual hallucinations in the presence of normal cognition and insight. It usually occurs in elderly people with ophthalmic pathology causing severe visual sensory deprivation. Our experience suggests that this syndrome is frequently overlooked or misdiagnosed by both ophthalmologists and psychiatrists. To our knowledge this is only the second series of cases of the syndrome in the American literature.

Adult↗
PubMed1990

[Axiographic irregularities in patients with different clinical function statuses].

A group (n = 20) of young, clinically symptom-free subjects (Helkimo Di = 0) was compared with a group (n = 22) of TMJ-patients (Di greater than 2) regarding the frequency and the amount of axiographic findings of malfunction. 5 different mandibular movements were monitored using the SAS-system with tenfold magnification in 2 planes of recording. An analysis of these results showed significant effects in several parameters. According to these findings the highest reliability to detect functionals differences is at the maximum distance between the ex- and incursive tooth-guided protrusive path in the sagittal-vertical plane. Although other parameters showed only slight discrepancies, a cautious interpretation of axiographic tracings must be recommended.

Dental Occlusion↗
PubMed1989

Continuous monitoring of mixed venous oxygen saturation in infants after cardiac surgery.

Continuous mixed venous oxygen saturation (SvO2c) was measured in 16 infants immediately after cardiac surgery. A polyurethane 4F, dual channel catheter (Opticath, Modell U440, Oximetrix) with fiberoptic filaments was introduced into the pulmonary artery during cardiothoracic surgery. The catheters were left in place for an average of 67.5 h (range 27 h -125 h) and there were no catheter-related complications. Correlation between continuous in vivo SvO2 values and in vitro values was satisfactory (r = 0.85), whereas a correlation between SvO2c and arterial oxygen saturation (SaO2) was not found (r = 0.07). The sampled arterial lactate values were inversely correlated to the simultaneously measured SvO2c, but the correlation coefficient was only r = -0.4. There was an inverse correlation between SvO2c and arteriovenous oxygen content difference (Ca-vDO2) (r = -0.82), and a marked inverse correlation to the calculated oxygen utilization ratio (r = -0.97). Therefore SvO2c continuously reflects the overall balance between oxygen consumption and delivery, but the use of SvO2 as a predictor of blood lactate levels is unreliable. A further purpose of the present study was to demonstrate the clinical applications and to show the usefulness of SvO2c-monitoring; particularly as a surveillance and early warning system, as a guide for assessing therapy and its relevance in interpreting other monitored parameters. In our opinion continuous SvO2 measurement is a reliable and valuable indicator of cardiopulmonary function in the immediate post-operative period, even in infants with complicated repair of cardiac malformations.

Blood Gas Analysis↗
PubMed1989

[The results of scanning electron microscopy research on interdental stripping in vitro].

In an in-vitro study the abrasive qualities of different orthodontic finishing strips were evaluated on the enamel surfaces of human teeth by means of a scanning electron microscope. As a result we can state that even the use of the finest finishing strip cannot eliminate the deep furrows that resulted from prior abrasion with a strip that is more coarse. The remaining furrows caused by the abrasive procedure are so deep and wide, that plaque accumulation may well be expected therein, and thus be predisposing for caries and periodontal pathology.

Dental Enamel↗
PubMed1989

[A comparison of axiographic tracings before and after orthodontic-oral surgical interventions].

Examination of patients who underwent orthognathic surgery showed, that axiographic tracings of the TMJ's change between a pre- and a 2.5 months postsurgical check-up. Typical changes such as shortening and loss of curvature of the TMJ's were detected. Axiographic findings after 7.5 months show that there is a reversion to initial functional patterns as well as formation of altered patterns.

Dental Occlusion↗
PubMed1989

A new method using simple solid phase extraction for the rapid gas-chromatographic mass-spectrometric determination of 11-dehydro-thromboxane B2 in urine.

A new gas-chromatographic mass-spectrometric method for the rapid determination of 11-dehydro-thromboxane B2 in urine, the major metabolite of systemic thromboxane formation, has been developed. Excellent sample clean-up was obtained in a single step by adsorption of 11-dehydro-TXB2 on phenylboronate cartridges, vigorous polar and organic washing and elution with an acidic methanol mixture. Then the pentafluorobenzylester trimethylsilylether derivative of 11-dehydro-TXB2 was formed and quantified in isotope dilution technique by negative chemical ionisation gas-chromatography tandem mass-spectrometry. The daughter fragments m/z 243/247 of the parent ion m/z 511/515 were monitored. Recovery was linear and quantitative over a wide range, accuracy was 95 + 7% and precision was 11% down to the very low pg range in biologic samples. Independent validation of this very fast extraction method with a reference method applying extensive sample purification with consecutive reversed and straight phase extraction, precolumn derivatisation, reversed phase high pressure liquid chromatography and tandem gas-chromatography mass-spectrometry gave excellent agreement of values. Values for 11-dehydro-TXB2 excretion in 8 healthy controls were 501 + 298 (range 231 to 1141) ng/g creatinin. Excretion was suppressed by aspirin, moderately elevated in heavy smokers (range 680 to 1540) and increased in patients with venous thrombosis or pulmonary embolism (2370 to 13350 ng/g creatinin). This rapid extraction method is useful for the highly specific and sensitive determination of 11-dehydro-TXB2 in large sample numbers.

Chromatography, High Pressure Liquid↗
PubMed1989

Prognostic factors in small-cell carcinoma of the lung: an analysis of 1,521 patients.

Cancer and Leukemia Group B (CALGB) accrued 1,745 patients with limited (LD) or extensive (ED) small-cell lung cancer (SCCL) to five separate trials between 1972 and 1986. We reviewed these data to evaluate the impact of pretreatment prognostic factors on outcome. In multivariate analysis, female gender was predictive of improved response (LD, P = .01; ED, P = .04) and survival (LD, P = .01; ED, P = .02). A performance status of 0 or 1 was associated with improved response rates in both subsets, but was statistically significant (P = .04) only for overall objective response in LD patients. Performance status was a highly significant predictor of survival in both LD and ED groups (P less than .001). Supraclavicular lymph node involvement, while still LD, had a borderline unfavorable impact on survival (P = .06) compared with a lesser extent of LD involvement. In ED patients, a decrease in survival rates was associated with an increased number of metastatic sites (P = .01). Changes in the patient population were noted with time: the percentage of women increased from 21% to greater than 35%; an increased number of metastatic sites was identified among ED patients; mean performance status improved for both LD and ED subsets. These trends reflect the changing demographics of lung cancer, improved lung cancer staging, and probably lead-time bias. Response rates, overall survival, and long-term (greater than 2-year) survival varied significantly among the five protocols, both before and after multivariate correction for identified prognostic variables. However, the changing character of the study population limits the ability to determine retrospectively how much improvements in therapy contributed to the positive changes in failure-free survival, overall survival, and long-term survival observed in our sequentially studied population.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1989

A randomized trial of anticoagulation with warfarin and of alternating chemotherapy in extensive small-cell lung cancer by the Cancer and Leukemia Group B.

The Cancer and Leukemia Group B (CALGB) conducted a prospective randomized trial to evaluate the role of warfarin and alternating chemotherapy in extensive small-cell lung cancer (SCCL). After stratification for sex and performance status, patients were randomly assigned to receive chemotherapy with methotrexate, doxorubicin (Adriamycin; Adria Laboratories, Columbus, OH), cyclophosphamide, and lomustine (CCNU) (MACC), or MACC plus warfarin (MACC + W), or mitomycin, etoposide, cisplatin, and hexamethylmelamine alternating with MACC (MEPH/MACC). Warfarin was given continuously to maintain a prothrombin time of one and one half to twice the control values. A total of 328 patients were enrolled, and 294 were evaluable. There was a statistically significant advantage in objective response rates (complete [CR] and partial responses [PR], respectively) for MACC + W (17% and 50%) as compared with MACC alone (8% and 43%) or MEPH/MACC (10% and 38%) (P = .012). Both failure-free survival (P = .054 Wilcoxon test) and overall survival (P = .098 Wilcoxon test) were higher on MACC + W (median, 6.6 months and 9.3 months, respectively), as compared with MACC (5.0 months and 7.9 months) and MEPH/MACC (5.0 months and 7.9 months). Toxicity was comparable among the three arms, except for increased hemorrhagic events on MACC + W, which were life-threatening in four patients (4%), and lethal in two others (2%). These data support the role of warfarin in the treatment of SCCL, but do not establish its mechanism of action. Warfarin deserves further studies in SCCL, particularly in patients with limited disease.

Altretamine↗
PubMed1989

[Studies on the reliability of axiographic recordings using the SAS system].

The objective of this study was to compare the differences in the electronic axiographic tracings within one axiographic examination and the differences between two axiographies, with respect to the reliability of their length, curvature and inclination values. 22 patients with varying degrees of TMJ dysfunction were examined using the SAS system after Meyer/Dal Ri. The results indicated a high degree of reliability within one axiography, but a remarkably reduced reliability when comparing two axiographies. In both comparisons maximal mouth opening was significantly less reliable than protrusive and lateral movements, irrespective of whether these movements were occlusally guided or TMJ-guided. No significant differences could be found between occlusally and TMJ-guided movements and between patients with different functional status values (Helkimo dysfunction index 0 and 1 as against 2 and 3).

Dental Articulators↗
PubMed1989

[Differences of clinical and axiographic function parameters in patients with skeletal Class II and Class III anomalies].

21 young individuals with skeletal and dental class II-relationships were compared to an analogous group of class III individuals as to their mandibular range of motion. The measurements of clinical movements in pro- and laterotrusion as well as the lengths of axiographic tracings showed a significantly reduced capacity of motion in the class III group. Because all examined individuals exhibited undisturbed TMJ-function or, at most, had mild symptoms (Helkimo-indexes 0 or 1), the reported findings cannot be interpreted as signs of pathology, but seem to demonstrate the broad range of normality.

Humans↗
PubMed1989

[Value of electronic measuring instruments for optimizing functional TMJ diagnosis].

In order to get additional information about the significance of electronic axiographic recordings in TMJ-diagnosis, 34 patients, who showed 47 clicking TMJs, were examined by use of an electronic axiographic instrument (SAS-system). The frequency of the detected findings emphasize the value of electronic axiographic devices for differential diagnosis. In detail the following conclusions could be drawn: examination of different types of movement is recommended because clicking must not exist in all types, recording in more than one plane is necessary in order to detect the (prevailing) plane of dislocation, a magnification of tracings provides addition information concerning different types of clicking.

Electronics, Medical↗
PubMed1989

[Changes in axiographic patterns in orthodontic treatment. A comparison of findings in upper and lower early displacement pre- and two month post-operation].

It has been shown that electronic axiographic tracings of patients 2.5 months after a surgical advancement of the maxilla by Le-Fort-I osteotomie changed only slightly in comparison to preoperative tracings. The sagital opening path as well as the sagital protrusive path showed alterations in curvature. On the other hand sagital split osteotomie with consecutive advancement of the mandible influenced axiographic patterns profoundly. We found almost regularily shortenings of the tracings and often loss of curvature.

Humans↗
PubMed1989

[The reliability of axiographic tracings].

The aim of this study was to compare the within- and between-session reliability of axiographic tracings. 22 patients with different degrees of TMJ dysfunction were examined using the SAS system. Within one and between two axiographies, respectively, the most frequent evaluation according to an index assignment was "very good". However, when tracings between two axiographies were compared the evaluations "extensive", "low", or "none" could be found in a considerable number of cases. These findings indicate a loss of reliability of irregularities between two axiographies. Testing of differences in reliability between different types of movement showed no significant effects.

Adult↗