An XPS and SEM evaluation of six chemical and physical techniques for cleaning of contaminated titanium implants

The purpose of the present study was to analyse clinically failed and retrieved implants prior to and after cleaning by means of scanning electron microscopy (SEM) and X-ray induced photoelectron spectroscopy (XPS) as compared to unused controls. Six different chemical and physical techniques for cleaning of contaminated titanium implants were evaluated: 1) rinsing in absolute ethanol for 10 min, 2) cleaning in ultrasonic baths containing trichloroethylene (TRI) and absolute ethanol, 10 min in each solution, 3) abrasive cleaning for 30 s, 4) cleaning in supersaturated citric acid for 30 s, 5) cleaning with continuous CO2-laser in dry conditions at 5 W for 10 s, 6) cleaning with continuous CO2-laser in wet conditions (saline) at 5 W for 10 s. SEM of failed implants showed the presence of contaminants of varying sizes and XPS showed almost no titanium but high carbon signals. XPS of unused titanium implants showed lower levels of titanium as previously reported, probably due to contamination of carbon which increased with time in room air. Cleaning of used implants in citric acid followed by rinsing with deionized water for 5 min followed by cleaning in ultrasonic baths with TRI and absolute ethanol gave the best results with regard to macroscopical appearance and surface composition. However, as compared to the unused implants the results from an element composition point of view were still unsatisfactory. It is concluded that further development and testing of techniques for cleaning of organically contaminated titanium is needed.     

Reporting levels of spinal blockade

With spinal anesthesia the level of surgical analgesia is mostly reported without reference to the neuroanatomic map of spinal nerves. The classical maps are variably and inconsistently reported in many textbooks. Because of the differences between the classical maps of Keegan and Garrett and of Foerster, and also because of the variability in their interpretation, we applied them to the same clinical data. This resulted in a theoretically clinically significant difference of two segments. It is concluded that clear reference should be made to the implemented segmental map in expressing the level of spinal blockade.     

On language laterality in normal dextrals and sinistrals: Results from the Bilateral Object Naming Latency Task

Rasmussen and Milner [N.Y. Acad. Sci. Vol. 299, pp. 355–379, 1977] published data on late-lesioned (after age 6) epileptic patients who had suffered left hemisphere lesions. They estimated that left hemisphere dominance occurred in 96% of dextrals and 70% of sinistrals. These figures have been regarded as valid estimates for normal dextrals and sinistrals. We administered the Bilateral Object Naming Latency Task, a verbal tachistoscopic task with very good psychometric properties, to 188 dextral and 72 sinistral normals. Results showed that 93.6% of the dextrals and 80.3% of the sinistrals were left hemisphere dominant. A consideration of results from a number of carefully conducted dichotic listening studies suggests, as do present results, that the 70% left-dominance estimate of Rasmussen and Milner for normal sinistrals may be too low by about 10%. It is suggested that ‘bilateral dominance’, present in 15% of the epileptic sinistrals of Rasmussen and Milner, may be much less common in normal sinistrals.     

Medical removals of the Multiload IUD

In a follow-up evaluation of 3721 Multiload IUD users, the removal rate for medical reasons other than bleeding/pain was only 2.6 per 100 women at three years. Most of these removals were for reasons that appeared to be unrelated to IUD use. The removal rate for pelvic inflammatory disease was 0.3 per 100 woman years. Women were followed up for up to three years after removal of their IUDs. Among women with PID at least 70% of those who desired pregnancy subsequently became pregnant, a rate similar to that of women who had their IUDs electively removed to become pregnant. The study provides further data on the safety of intrauterine contraception.

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Resumen Durante el seguimiento de 3721 usuarias del DIU Multiload, la tasa de remociones por otras razones médicas que sangrado/dolor, fué de 2.6 por 100 mujeres en tres años. La mayoría de estas remociones fueron hechas por razones que parecen no estar relacionadas con el uso del DIU. La tasa de remociones por enfermedad inflamatoria pelviana fué de 0.3 por 100 años-mujer. Las mujeres tuvieron seguimiento hasta tres años después de la remoción de sus DIU. Entre las mujeres con enfermedad inflamatoria pelviana, al menos 70% de las que desearon un embarazo lo consiguieron; una tasa similar a la de mujeres que eligieron la remoción del DIU para quedar embarazadas. El estudio proporciona más información sobre la inocuidad de la anticoncepción intrauterina.

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Résumé Lors d'une évaluation de suivi effectuée sur 3721 utilisatrices de DIU Multiload, le taux de retrait pour des raisons médicales autres que des pertes sanguines/douleurs n'a atteint que 2,6 pour cent des femmes après trois ans. La plupart de ces retraits ont été pratiqués pour des raisons qui ne semblaient pas liées à l'utilisation du DIU. Le taux de retrait pour cause d'inflammation pelvienne s'est élevé à 0,3 pour cent femmes-an. Les femmes ont été suivies pendant des périodes allant jusqu'à trois ans après le retrait du DIU. Parmi les patientes qui avaient contracté une inflammation pelvienne, 70% au moins de celles qui souhaitaient une grossesse sont par la suite devenues enceintes; taux semblable à celui des femmes qui avaient choisi de ne plus porter leur DIU précisément pour avoir un enfant. Cette étude fournit des données supplémentaires sur la sécurité qu'apporte la contraception intrautérine.

     

Ecology of a Southern Ohio stream receiving fly ash pond discharge: Changes from acid mine drainage conditions

Prior to 1975, Stingy Run was a third-order tributary of Kyger Creek, which empties into the Ohio River at Mile 260 (Gallia County, Ohio). Both streams drained strip mine refuse areas and physicochemical measurements indicated acidicmine drainage conditions (e.g., low pH). A depauperate macroinvertebrate community, dominated by a few acid-tolerant taxa, was found in both streams and no fishes were collected. In 1974, Stingy Run was impounded to form a fly ash pond which contains fly ash sluiced from Ohio Power Company's General James M. Gavin coal-fired power plant. Physicochemical and biological sampling during 1975–1986 indicated marked changes in the aquatic ecology of Stingy Run between 1) pre-impoundment and post-impoundment conditions; and 2) effluent pH control treatments after impoundment. Fly ash discharge eliminated acidicmine drainage characteristics in Stingy Run and lower Kyger Creek. After impoundment, net spinning caddisflies and a few dipteran taxa dominated the Stingy Run benthic community, reflecting changes in functional niches likely due to improved habitat and greater food availability. Replacement of acid feed by CO₂ injection for effluent pH control and changes in ash pond chemistry occurred concomitant with elimination of a substrate floc; increased species richness and densities of invertebrates were subsequently observed. In Stingy Run, species richness and diversity of fishes increased from 1983 to 1986, reflecting improved water quality and increased benthic production after impoundment. Many of these fishes are opportunistic feeders on drifting insects.     

Increased collagen IV layer in the basal membrane area of the capillaries in severe chronic venous insufficiency

Lipodermatosclerosis is a sign of severe chronic venous insufficiency. In this stage of CVI one can find capillary leakage of water and plasmaproteins which results in a higher capillary filtration rate. In skin biopsies the result of this process can be seen as a pericapillary halo. The group of Burnand recently described fibrinogen deposits in this area. We studied the capillaries and their surrounding tissue to determine the thickness of the collagen IV deposits. In severe CVI with lipodermatosclerosis a significant increase of the collagen IV layer was observed. Collagen IV thickness was measured by an index method. The collagen IV thickness for this purpose refers to the capillary diameter. It can be suggested that the increase of the venous pressure in the capillaries leads to leakage of several proteins and namely fibrinogen. As a result of the increase of fibrinogen the collagen IV layer becomes thicker which leads to a decreasing function of the capillaries. In this way an auto-amplification mechanism maintains CVI. An other explanation can be induction of collagen IV due to the high capillary pressure in CVI.     

R 75251, a new inhibitor of steroid biosynthesis

R 75251, a new imidazole derivative, inhibited the conversion of androgens to estrogens, of progestins to androstenedione and testosterone, and of 11-deoxycorticosterone to corticosterone in human placenta microsomes, subcellular fraction of rat testis, bovine adrenocortical mitochondria, in cultured rat granulosa, testicular and adrenal cells, respectively. In vitro, no effect on cholesterol synthesis and cholesterol side-chain cleavage was found at concentrations up to 10 microM. In rat granulosa cells, no effect on progesterone production was detected. In vitro, no effect on steroid radioligand binding was observed. In male volunteers, a single dose of 300 mg of R 75251 significantly lowered plasma testosterone and estradiol for 24 hours and increased plasma concentration of 17 alpha-hydroxyprogesterone and progesterone. As compared with ketoconazole high dose (600 mg b.i.d), R 75251 (300 mg b.i.d) was at least as efficacious as inhibitor of testosterone synthesis when studied during ACTH stimulation. In contrast to ketoconazole, R 75251 did not significantly affect circulating adrenal androgen levels in male volunteers. Precursors of gluco- and mineralocorticoids such as 11-deoxycortisol and 11-deoxycorticosterone accumulated more than after ketoconazole administration. The data show that the cytochrome P450-dependent aromatase, 17-hydroxylase/17,20-lyase, and 11-hydroxylase are the target enzymes for R 75251.     

Development of progressive glomerulosclerosis in experimental chronic serum sickness

A rat model of chronic serum sickness was used to study the pathogenesis of progressive glomerulosclerosis complicating experimental immune-complex glomerulonephritis. Chronic serum sickness was induced by immunising rats with bovine serum albumin followed by intraperitoneal administration of the antigen. Early lesions consisted of mesangial deposits of rat immunoglobulins, followed later by transient subendothelial and persistent subepithelial immune aggregates. On the basis of the peak level of proteinuria around day 80, three groups of rats were distinguished: I physiological proteinuria; II 50-500 mg/24 h; and III greater than 500 mg/24 h. The animals were killed at day 220 and the presence of mesangial proliferation, epithelial proliferation, and synechiae, as well as focal glomerulosclerosis was scored. It appeared that all and only proteinuric animals developed progressive glomerulosclerosis, although all three groups of animals passed through a phase with mesangial and subendothelial immune deposits. A strong correlation was found between the degree of proteinuria and the proportion of glomeruli affected. We conclude that the combination of mesangial and subendothelial deposits on the one hand and subepithelial deposits associated with increased protein loss on the other constitute a conditio sine qua non for the development of progressive glomerulosclerosis in this model. The use of specific antibodies to investigate the composition of the sclerotic lesions showed the presence of laminin and type IV collagen, but not of types I and III collagen in sclerotic areas of glomeruli. This indicates that the development of progressive glomerulosclerosis in this model is due to an increased production of glomerular basement membrane components by presumably solely glomerular cells after the occurrence of immunological glomerular injury.