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PubMedDate not supplied

Microradiography of the collecting ducts in the perfusion fixed rabbit kidney: suggestions for the anatomic basis for the radiographic appearance of cortical striations and intrarenal reflux.

Perfusion fixation was used to preserve the rabbit kidney, in its in vivo state (open tubules). Barium sulfate was either injected through the renal artery at a pressure sufficient to cause postulated microruptures in the glomerular tufts and opacify the tubules, or refluxed via the ureter to opacify the collecting ducts and tubules to the level of Bowman's capsule. The anatomy of the collecting ducts and their relationships to the nephrons were demonstrated, allowing suggestions for the anatomical basis for the radiographic appearances of cortical striations and intrarenal reflux.

Animals↗
PubMed1989

Comparative histopathology, microradiography and per-rectal ultrasonography of the prostate using cadaver specimens.

A technique for examining cadaver prostates by per-rectal ultrasonography has been developed. The ultrasonic plane was defined and corresponding sections taken for microradiographic and histopathological examination. The technique has enabled a comparison to be made of the structural changes that occur in the prostate in disease states and the corresponding ultrasonic features.

Adolescent↗
PubMed2007

Monitoring of the heavy-metal hyperaccumulation in vegetal tissues by X-ray radiography and by femto-second laser induced breakdown spectroscopy.

This article reports on the utilization of X-ray microradiography and laser induced breakdown spectroscopy (LIBS) techniques for investigation of the metal accumulation in different part of leaf samples. The potential of the LIBS-analysis for finding the proper plant species for phytoremediation is compared with the results of microradiography measurements at the HERCULES source at ENEA, Rome (Italy) and X-ray microradiography experiments at the ELETTRA Synchrotron, Trieste (Italy).

Cadmium↗
PubMed1987

SEM and microradiographic investigation of initial enamel caries.

In this paper a combined microradiography and SEM study is presented on human enamel after a caries attack in vivo for a 4-wk period. The initial enamel caries is induced under a specially designed orthodontic band; plaque accumulation takes place under a niche in the band. The microradiography and SEM were done on the same sections. A special manipulation and breaking technique of the thin sections makes it possible to observe with the SEM, demineralized enamel areas with a mineral content known from microradiography. The results show that with a mineral content of about 50 vol. %, the observable porosity is noticeable at the prism level (interprismatically) but barely noticeable at the cyrstallite level. The surface morphology of the demineralized enamel is at low magnifications not very different from sound enamel. At high magnifications, however, the surface porosity becomes visible. The results indicate that the mineral in vivo losses in enamel after an initial caries attack can be explained mainly by mineral losses from interprismatic areas and from the prism peripheries.

Adolescent↗
PubMed1989

Dentine caries in vivo. Combined scanning electron microscopic and microradiographic investigation.

Dentine subjected to an in vivo demineralization challenge by plaque looses substantial amounts of mineral and is expected to change its ultrastructure. Results are presented of a combined microradiography and scanning electron microscopy (SEM) study on in vivo demineralized human dentine. The tissue was first demineralized in vivo under plaque for 3 weeks and subsequently analyzed by microradiography and SEM. In 6 participants dentine was positioned in a full prosthesis just under M2 in such a way that the outer surface of the tissue was 1.5 mm lower than the surface of the prosthesis; plaque accumulation takes place in the recessed area. A special technique allows SEM observations (at a given distance from the outer surface) on broken thin sections of demineralized dentine with a mineral content determined by microradiography. The results show that the ultrastructure of the dentine changes during severe demineralization. The main ultrastructural features are, however, still largely intact, even if half of the mineral originally present has been lost. In dentine with a mineral content of about 25 vol%, the dentinal tubules are enlarged by about 30%. In vivo demineralized dentine looses mineral in substantial amounts both from intertubular and from peritubular regions.

Adolescent↗
PubMed1992

Comparison of fluoride profiles by SIMS with mineral density of subsurface enamel lesions treated intra-orally with a fluoride-releasing device.

A variety of intra-oral model systems has evolved which allows for the study of remineralization of coronal and/or root-surface lesions following application of topical fluoride (F) agents. The problem of interpretation of the results has led to a variety of analytical methods (i.e., microhardness, F biopsy, microradiography, and polarizing light microscopy), each of which provides important but limited information related to the overall understanding of remineralization. Microhardness measures change in mineral content which is more precisely localized by microradiography and polarized light microscopy. F biopsy allows for assessment of the F uptake of lesions, but does not suggest the chemical state of the F. Previous work has demonstrated that patterns of mineral deposition during remineralization do not necessarily parallel the F uptake profiles, and fluoridated apatites cannot be distinguished from non-specifically-adsorbed F (Clark et al., 1988). Because artificial lesions demonstrate variations in depth and mineral content, complementary analytical methods that demonstrate profiles of both F content and mineral density curves on the same section are needed so that the process of remineralization can be more clearly understood. This study used secondary ion mass spectrometry (SIMS) for F profiles and quantitative microradiography for assessment of mineral deposition on the same section. These state-of-the-art methods demonstrate the precision with which information about remineralization can be obtained. Subsurface lesions in human enamel specimens were developed by immersion in 0.1 M lactate buffer with 1% CMC at a pH of 4.5 for 48 h.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1978

Microradiographic study of cerebral and ocular aneurysms in hypertensive rabbits.

Cerebral and ocular microaneurysms were produced in rabbits made hypertensive by surgically induced silk-turpentine perinephritis combined with contralateral nephrectomy 7 days later. The aneurysms distributed throughout the brain and iris were studied by microradiography; a few representative aneurysms selected from the microradiographs were studied histologically. The microradiographic findings and histological sections correlated well. Intracranial microaneurysms were multiple and frequently located in the basal ganglia and near the cortex. Arterial changes in the iris paralleled intracranial arterial changes in degree and type except for the addition of hemorrhage around some microaneurysms. The results of this study show the potential of microradiography and histological sections guided by microradiography for studying the natural history of hypertensive arterial lesions and support the contention that hypertension, microaneurysms and intracerebral hemorrhages are related.

Aneurysm↗
PubMed2000

Measurement of bone metal contact (BMC) in retrieved maxillofacial osseointegrated implants.

Eighteen screw-shaped extraoral osseointegrated implants retrieved from 10 patients were analysed by microradiography. Retrieved implants were trephined with a border of surrounding bone, fixed, embedded in epon plastic, ground and processed for microradiography. The reasons for retrieval were unexplained pain (n = 4), inability to cope with the implants (n = 2), fracture of central screw (n = 2), skin penetration problems (n = 1) and trauma (n = 1). The study group comprised six males and four females with a mean age of 53.4 years (range: 9-81 years). All implants were clinically stable at the time of removal, and mean osseointegration time was 3 years (range: 1-5 years). Six implants were removed from the temporal bone, five from the frontal bone and seven from the maxilla. Bone metal contact was estimated to vary between 27% and 83%. Bone metal contact was lower in the frontal bone compared to the temporal bone or maxilla, and was further reduced after preoperative irradiation. Longer osseointegration time increased bone metal contact, as did increased age up to 60 years. It is concluded that extraoral osseointegrated implants in humans may integrate morphologically as well as clinically. By microradiography it was possible to define bone metal contact in the region of implant installation.

Adolescent↗