Biostereometric quantification of clinical denture tooth wear

In this study the wear of mandibular acrylic resin teeth opposed by porcelain maxillary teeth arranged in a lingualized occlusal scheme over a period of 3 years was measured. Six edentulous subjects received complete dentures as above and with three baseline markers of amalgam. At yearly intervals casts were made of the mandibular occlusal surfaces, including markers, and plotted by stereophotogrammetry. Volumetric loss of material was quantifiable. Ranges of 0.62-3.33 mm3/mm2 on the left side and 0.71-1.64 mm3/mm2 on the right were recorded. Friedman two-way ANOVA test indicated significant wear on teeth 35, 36, 45 and 46 but not on 34 and 44. A one-sided chewer displayed greater wear on the contralateral side, a finding difficult to explain.     

Biosynthesis and conformational state of 17-kDa and 27-kDa N-terminal fragments of elongation factor EF-2 in solution

N-Terminal fragments of the rat liver elongation factor EF-2 containing 162 (17 kDa) and 244 (27 kDa) amino acid residues of 857 (95 kDa) residues of the native protein were synthesized in E. coli cells and in a wheat germ cell-free translation system, and their conformations were studied. Both fragments were synthesized as inclusion bodies (nonspecific molecular aggregates). The conformations of the fragments in a solution were studied at neutral pH values by CD, fluorescence spectroscopy, scanning microcalorimetry, viscosimetry, gel-filtration, limited proteolysis, and interaction with monospecific anti-EF-2 antibodies and GroEL/ES molecular chaperone. Under nondenaturing conditions, both fragments existed in a solution as associates within a broad range of molecular masses, contained a considerable amount of elements of the intramolecular secondary structure, and represented globules without rigid tertiary structure (molten globules). A rigid tertiary structure was not formed even after the interaction of the fragments with the GroEL/ES molecular chaperone, thus indicating that the C-terminal fragment is essential for the formation of the rigid tertiary structure. Both fragments contained conformational antigenic determinants similar to those in the whole protein; i.e., despite the absence of the rigid tertiary structure, the fragments contained elements whose structure was similar to that of the corresponding regions in the whole protein.     

Drug-induced alterations of the hypothalamus-hypophysis axis

Omitting hormonal variations caused by other drugs already objects of research, the behaviour pattern of GH, PRL, TSH, following acute administration of cimetidine, nomifensine, domperidone has been considered in normal subjects, in patients with pituitary non-secreting and PRL-secreting adenomas and in patients with amenorrhea-galactorrhea syndrome without evidence of adenoma. The results confirm the influence which drugs employed in the therapy of non-endocrine diseases provide a way to alter the functions of the hypothalamus, sometimes relatively specifically, and the secretion of pituitary hormones provides us with a possibility of analyzing the CNS output.     

Use of the swarming phenomenon for the purpose of isolating pure cultures of salmonellae from feces. I

The authors elaborated and tested a number of elective-differential media for swarming of salmonellae. When pure cultures of Proteus, E. coli and salmonellae were seded on these media the latter exeeded the rest of enteric bacteria by the intensity of swarming. In the capacity of saprophyte inhibitors the most effective were media with the addition of penicillin and sodium selenite. Satisfactory results were obtained on the mentioned media in isolation of salmonellae from the artificially contaminated feces by the method of swarming     

Postural adaptations to workbench modifications in standing workers

Surveys have shown that many workers operate under conditions that require constrained standing. The aim of this study was to investigate postural adaptations in constrained standing to facilitate the development of design guidelines for standing workspaces. Standing postures were observed in six different workspaces that were designed using combinations of task distance (which was either constrained or unconstrained) and foot position (which was constrained, unconstrained or employed a footrest). Subjects at work were recorded stereophotogrammetrically and postural variables were obtained in three dimensions. Postural adaptation to increased task distance was found to be characterized by increased trunk flexion and increased hip flexion while adaptation to close work was found to be characterized by increased neck flexion and increased thoracic kyphosis. Constrained foot position resulted in increased hip flexion accompanied by increased plantar flexion. Although use of the footrest resulted in some reduced lumbar lordosis, it increased trunk flexion and was not associated with significantly less discomfort than any of the other workspaces.     

Remodeling dynamics of bone supporting rigidly fixed titanium implants: a histomorphometric comparison in four species including humans

The long-term maintenance of a rigid bone-implant interface (osseointegration) is the clinical goal of most dental implant systems, although the biological mechanism for retaining a foreign object in living bone is unclear. Little data are available on the physiological turnover (remodeling) of the supporting osseous tissue. The objective of this study was to histomorphometrically assess bone remodeling surrounding rigidly integrated titanium implants in multiple species. Implants, in place from 6 months to 5 years, were recovered from human, monkey, dog, and rabbit subjects. With the use of stereological point-hit and linear-intercept methods, indices of bone formation and resorption were determined. Remarkably similar patterns emerged among all investigated species. Repeated-measures ANOVA showed a 3 to 9 fold increase in remodeling within 1 mm of the bone-implant interface (P<0.001; data expressed as percent turnover / month, mean +/- SEM for n = 3-11). All morphometric indices (percent new bone, percent fluorochrome-labeled bone, percent resorption space) showed similar trends. These data suggest that the physiological mechanism for maintaining rigid osseous integration (osseointegration) is a sustained elevation of remodeling adjacent to the bone-implant interface.     

Regression of prostatic cancer metastasis by high doses of diethylstilbestrol diphosphate

Diethylstilbestrol diphosphate (DES-P) has shown effective symptomatic relief in patients with metastatic carcinoma of the prostate. Although there is little known about its role in soft tissue metastasis, our experience in 3 patients with advanced carcinoma of the prostate infiltrating the trigone and ureterovesical junction revealed significant improvement of hydronephrosis. All patients failed to respond to conventional doses of stilbestrol. Diethylstilbestrol diphosphate is recommended in the treatment of advanced carcinoma of the prostate with soft tissue metastasis. It is safe and effective, and the tumor responses outweigh the side effects of the drug. The mechanism of action of this compound is discussed.