Comparison of the acoustic streaming in amniotic fluid and water in medical ultrasonic beams.

AIM: Acoustic streaming in amniotic fluid has been investigated under a variety of conditions relevant to the diagnostic use of ultrasound. METHOD: An ultrasonic Doppler method has been used for measurement. Streaming velocities have been compared with those generated in water for the same exposure conditions. Beams were generated by laboratory equipment simulating beams from clinical systems. The fluids were insonated IN VITRO using 3.5 MHz, 5 MHz and 7.5 MHz transducers in continuous wave (CW) and pulsed mode. RESULTS: Acoustic streaming was measured in both amniotic fluid and water at the power levels 50 mW and 140 mW. Enhancement of velocities due to non-linear effects in high amplitude pulses was demonstrated for amniotic fluid as well as for water. The potential and limitations of present numeric methods for the prediction of acoustic streaming were explored. CONCLUSION: Pulsed ultrasound caused similar streaming velocities in amniotic fluid and water while continuous wave beams induced significantly faster streaming in amniotic fluid than in water.

Perforin expression is upregulated in the epidermis of psoriatic lesions.

BACKGROUND: There are currently very few data regarding the role of cell-mediated cytotoxicity in psoriasis. Both cytotoxic T lymphocytes and natural killer (NK) cells mediate cytotoxicity reactions, mainly by two distinct pathways, the perforin/granzyme and the Fas/Fas ligand pathway. OBJECTIVES: To study the expression and distribution of perforin, T- and NK-cell subsets in psoriatic lesional and nonlesional skin. METHODS: Skin biopsy specimens from both lesional and nonlesional skin of 11 patients with chronic plaque psoriasis and eight healthy controls were analysed by immunohistochemistry. RESULTS: We found a significant increase in CD4+ and CD8+ cells in psoriatic lesions compared with nonlesional and healthy skin. The expression of CD16+ NK cells was significantly lower in lesions compared with healthy skin. Perforin expression was significantly enhanced in the epidermis of psoriatic lesions. CONCLUSIONS: Perforin expression is upregulated in the epidermis of psoriatic lesions, suggesting a potential role for perforin in the creation of the psoriatic plaque.

Perforin expression in peripheral blood lymphocytes and skin-infiltrating cells in patients with lichen planus.

BACKGROUND: Current evidence suggests that lichen planus is a T-cell-mediated autoimmune disease in which cytotoxic mechanisms have been poorly investigated. OBJECTIVES: We investigated the expression of perforin in subpopulations of peripheral blood lymphocytes (PBL) in exacerbation and remission phases of the disease as well as in skin lesions. METHODS: We performed a simultaneous detection of perforin (intracellular molecule) and cell surface antigens on PBL by flow cytometry, and skin lesions were investigated by immunohistochemistry. RESULTS: The most interesting finding was a significant increase of perforin expression in cytotoxic T lymphocytes (CD3+ perforin+ cells) in the exacerbation phase of disease (P < 0.05), which was mostly located in the CD8+ subpopulation (CD8+ perforin+) (P < 0.01). Using immunohistochemistry we confirmed the infiltration of T lymphocytes in skin lesions, especially of CD4+ and CD8+ phenotypes, compared with uninvolved (P < 0.05) and healthy skin (P < 0.01). The expression of perforin was also significantly higher in lesional skin compared with nonlesional and healthy skin (P < 0.05). CONCLUSIONS: Our results clearly show the upregulation of perforin expression in peripheral blood as well as in lesions of patients with lichen planus and therefore suggest an important role for perforin in this autoimmune disease.

Studies of acoustic streaming in biological fluids with an ultrasound Doppler technique.

Acoustic streaming generated by diagnostic ultrasound fields is an important area for study both for safety reasons and because of its potential application as a diagnostic tool. A method of investigating streaming in biological fluids is reported. A number of fluids were insonated using a 3.5 MHz weakly focused single element transducer which was driven in pulsed mode. Streaming was detected in each fluid using an 8 MHz continuous wave Doppler system. The maximum streaming velocity was obtained by spectral analysis of the Doppler signal. Using this system longitudinal streaming profiles were measured. At an acoustic power of 150 mW the maximum streaming velocities detected were: 9.3 cm s-1 in water, 6.8 cm s-1 in 4.5% human serum albumin (HSA) solution and 4.9 cm s-1 in blood, when transmission was through a water path of approximately 10 cm into a 3 cm sample of fluid. When measurements were made in the biological fluids alone, without a water path, the maximum streaming velocities were reduced.

Sonographic measurement of absolute and relative renal length in adults.

PURPOSE: The aim of this study was to evaluate sonographically measured absolute and relative lengths of normal kidneys according to subject height, sex, and age. METHODS: Real-time sonography was performed on 202 subjects. Measurements of longitudinal renal diameter represented absolute renal length. Relative renal length was calculated using the kidney length: body height ratio (KBR). RESULTS: Statistical analyses were done on findings in 175 subjects without renal impairment (104 men and 71 women) whose ages ranged from 17 to 85 years (mean +/- SD, 46.3 +/- 17.1). The mean heights of the subjects were 176 +/- 7 cm for men and 167 +/- 6 cm for women. The left kidney was absolutely (mean +/-SD, 112 +/- 9 mm) and relatively (mean KBR +/- SD, 0.655 +/- 0.042) longer than the right kidney (absolute length, 110 +/- 8 mm; KBR, 0.641 +/- 0.038), regardless of sex (p < 0.01). The absolute renal length was significantly greater in men than in women for both kidneys (p < 0.01), but there was no significant difference between KBRs (p > 0.05). Renal length decreased with age, and the rate of decrease seemed to accelerate at 60 years and older. When height and age were included in the multivariate regression analysis, sex was not a significant predictor of kidney length. CONCLUSIONS: Relative renal length better represents kidney size than absolute renal length because it eliminates sex and height differences.

[Smoking behavior of Styrian physicians--results of a 1995 questionnaire survey]. / Rauchverhalten steirischer Arzte--Ergebnisse einer Fragebogenaktion 1995.

Tobacco use among all physicians registered in the state of Styria was investigated at the beginning of the year 1995 using an anonymous questionnaire. In addition to the smoking prevalence among different specialties in medicine the main interest was focused on motives for smoking as well as for stopping it. Nearly all physicians were aware of the associated health risks. The overall prevalence of smoking was 14% which lay markedly below the Austrian average of 36%. 52% started smoking before the age of 18. In addition 70% of smoking doctors wanted to reduce or stop smoking within the next 6 months. The early start of smoking during adolescence emphasizes the importance of educational and special teaching programs because even in the medical profession there is a big difference between the intention to stop smoking and the actual success in doing so.