Biomedical subjects
Publications and source records attributed to W Walther.
Missing data in a clinical trial may produce a change in the stratification of a controlled group. The method of statistical analysis employed should thus be designed for incomplete data to avoid false conclusions. This approach is illustrated in a realistic clinical example using cross-sectional and longitudinal data.
This study reports the clinical success rates of 6 different implant types inserted with defined clinical indications. The criterium used was implant loss. The survival periods of a total of 1723 implants were statistically evaluated according to Kaplan and Meier's method in relation to the type of implant used and the indication chosen.
The sequence similarities between Int-2 and members of the fibroblast growth factor (FGF) family have prompted functional as well as structural comparisons with other FGFs. Here we examine the ability of int-2 sequences to induced morphological transformation of NIH3T3 cells, a characteristic property of the secreted FGFs, such as FGF-5 and Hst1/kFGF. Despite encoding a short signal sequence, which directs the product to the secretory pathway, mouse int-2 DNA is incapable of inducing foci of transformation in the standard transfection assay. However, when transfected cells are enriched by co-selection with the neomycin resistance gene, a proportion of the int-2-expressing cells display a transformed phenotype, including the ability to grow as colonies in soft agar and in defined medium. Analyses of int-2 RNA and protein in these cells suggest that transformation by int-2 may require a threshold level of expression, and that the subsequent phenotype is dependent on the level of int-2 protein present in the cells.
A survival rate analysis of 426 CEREC restorations, made in a general dentistry practice, was carried out for a period of 3 years. 12 restorations were lost. Thus the Kaplan-Meier probability of survival decreased to 0.95 within 23 months. The mortality rates of restorations in molars and of restorations in premolars showed no significant difference. The patients assessed the treatment results in 96% of the cases as "good" or very good". In 4 cases chewing sensibility necessitated the reconstruction of the inlay restoration. With increasing observation time a reduced quality of the marginal integrity was found.
In Germany groundwater represents the main source for the water supply. Up to the present the nitrogen surplus due to agricultural production has increased to about 100 kg N/ha and year. This surplus reaches other, mainly aquatic ecosystems, transported by water and trough the air. The impact of the long-term load through nutrients on groundwater is exemplified here in the case of Lower Saxony. In karst and rock aquifers the transport velocities are usually relatively high. After nutrients have left the root zone of the soil there remains in this kind of aquifer little opportunity for nitrate decomposition. Therefore rising nitrate values can soon be observed in pumpage wells. Intensive cattle production is especially widespread in the northern parts of Lower Saxony. In these areas of sandy aquifers the period of substance transport between the input into the system and reaching pumpage wells may cover years or even decades. Therefore there is a greater chance for nitrate decomposition. Nonetheless many upper aquifers are severely contaminated with nitrates, for instance. In many cases a reductive chemical environment can be observed, which causes an increase in substances such as iron or trace elements like nickel. This leads to considerable problems for water supply and treatment. In order to protect the quality and decomposition capacity of the groundwater for the next generation it is urgently necessary to minimise nutrient surpluses in the field of agricultural production.
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int-2 was discovered as a proto-oncogene transcriptionally activated by MMTV proviral insertion during mammary tumorigenesis in the mouse. Sequence analysis showed int-2 to be a member of the fibroblast growth factor family of genes. In normal breast and most other adult mouse tissues, int-2 expression was not detected except for low levels in brain and testis. However, using in situ hybridization, expression was found at a number of sites during embryonic development, from day 7 until birth. An analysis of the int-2 transcripts found in embryonal carcinoma cells revealed six major classes of RNA initiating at three promoters and terminating at either of two polyadenylation sites. Despite the transcriptional complexities, all size classes of RNA encompass the same open reading frame. Using an SV40 early promoter to drive transcription of an int-2 cDNA in COS-1 cells, several proteins were observed. These were shown to be generated by initiation from either of two codons: One, a CUG, leads to a product which localizes extensively to the cell nucleus and partially to the secretory pathway. In contrast, initiation at a downstream AUG codon results in quantitative translocation across the endoplasmic reticulum and the accumulation of products ranging in size from 27.5 x 10(3) Mr to 31.5 x 10(3) Mr in organelles of the secretory pathway. These proteins represented glycosylated and non-glycosylated forms of the same primary product with or without the signal peptide removed. These findings suggest the potential for a dual role of int-2; an autocrine function acting at the cell nucleus, and a possible paracrine action through a secreted product.
The presented investigation was carried out on 19 individuals who were referred for prothetic and periodontal treatment. All patients suffered from advanced periodontal disease and had no more than 3 teeth left in the jaw going to be treated. Following a baseline examination comprising assessment of oral hygiene and tooth mobility the patients were subjected to prothetic and periodontal treatment. Removable partial dentures were constructed using the conical crown system. The patients were distributed into 2 different maintenance groups. 10 patients (group 1) were instructed to use the Bass Technique for cleaning the remaining abutment teeth. Group 2 applied proximal brushes for cleaning the interdental spaces prior to removing the partial dentures for cleaning as prescribed for group 1. Three months after treatment a reexamination was performed. In both groups a significant reduction of plaque was observed. The plaque scores of the second group were below those of the first group but the difference was statistically not significant.
A computer system for recording clinically relevant parameters is described. The system represents a modification of previous methods for the collection and evaluation of follow-up data. Once installed, it permits the observation of dental therapy and subsequent treatment measures without additional organizational requirements. The results show the number of cases that can be controlled over 5 years without special appointments for reexamination.
Crown fractures following prosthodontic treatment with tapered crowns were studied in a group of 209 controlled cases after a wearing period of 36 months. Out of a total of 841 abutment teeth 29 fractured. There was no correlation between the number of abutments and the risk of crown fracture. Incisors and canines were affected to the same extent as premolars. 27 teeth could be saved by post retention.
The survival rate of 2094 abutment teeth in 671 removable partial denture cases was analysed. Within an interval of 2-7 years 150 abutments were lost. The survival-rate of abutments in severely reduced dentitions differs significantly from that in dentitions with more than 3 teeth. Regarding the framework design there was no significant difference in the survival-rate of abutment teeth for removable partial dentures supported by more than 3 teeth.
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The extraction rate was studied in a group of 151 patients treated for periodontal and prosthodontic reasons. 29 of 588 abutments had to be extracted due to periodontal problems within a period of 6 years after prosthodontic treatment. The initial findings of the extracted teeth are correlated with the initial findings of all abutments. It can be shown that periodontally reduced teeth involve a higher risk of extraction; nevertheless, in the majority of the cases, they could be successfully used as abutments.