Light scattering by red blood cells in ektacytometry: Fraunhofer versus anomalous diffraction.

In the present literature on ektacytometry, small angle light scattering by ellipsoidal red blood cells is commonly approximated by Fraunhofer diffraction. Calculations on a sphere with the size and relative refractive index of a red cell, however, show that Fraunhofer diffraction deviates significantly from exact Mie theory. Anomalous diffraction is found to be a much better approximation.

Clinical evaluation of the CORDIS vascular access port systems: a multicenter study.

Two non-metallic vascular access port systems, the Multipurpose Access Port (MPAP) and Miniport, developed by CORDIS S.A., France, have been evaluated clinically in 78 cancer patients.

Bone growth and remodeling after distraction epiphysiolysis of the proximal tibia of the rabbit. Effect of electromagnetic stimulation.

The effect of pulsed electromagnetic stimulation on bone formation was tested in a lower-limb-lengthening model in the rabbit. Limb lengthening was performed by distraction epiphysiolysis. A specially designed external distraction device allowed 10 mm of lengthening of the tibia.

Effect of aniosmotic media on the volume of the T-lymphocyte nucleus.

Time-resolved measurements of the nuclear volume response of human peripheral T-lymphocytes, under aniosmotic conditions, are presented. In the experiments slit scanning FlowCytometry methods were used. We propose an extension to the standard solid viscoelastic model to interpret the observed dynamical behavior of the nucleus.

Effect of direct current stimulation on bone growth after distraction epiphysiolysis of the rabbit tibia.

The effect of direct current stimulation on bone formation during limb lengthening was tested in a lower leg lengthening model in the rabbit. Limb lengthening was performed by distraction epiphysiolysis. A specially designed external distraction device was placed at the tibia.

The value of local 99mTc(Sn)-MDP bone to soft tissue uptake ratio in osteoporosis, before and during fluoride therapy.

The reproducibility and diagnostic value of local bone to soft tissue uptake ratio of 99mTc(Sn)-MDP as a bone tracer was examined in a prospective study in 35 patients who were under investigation and/or treatment for postmenopausal osteoporosis. The ratio of tracer uptake in the second lumbar vertebra (L2) and both femoral shafts was calculated from the number of counts in suitable regions of interest. Results obtained with settings and calculations in the routine practice were compared to the results obtained by revision of all raw data in one run by one person.

Complexing of copper in drinking water samples to enhance recovery of Aeromonas and other bacteria.

The presence of copper in drinking water samples at concentrations as low as 10 micrograms/l resulted in a rapid die-off of aeromonads. Coliform bacteria, heterotrophic plate count bacteria and faecal streptococci were also sensitive to copper but to a lesser degree than aeromonads. The effect was particularly noticeable in soft water (less than 3 meq/l Ca + Mg) and at pH-values below 8.

Scattering matrix elements of biological particles measured in a flow through system: theory and practice.

Light scattering techniques (including depolarization experiments) applied to biological cells provide a fast nondestructive probe that is very sensitive to small morphological differences. Until now quantitative measurement of these scatter phenomena were only described for particles in suspension. In this paper we discuss the symmetry conditions applicable to the scattering matrices of monodisperse biological cells in a flow cytometer and provide evidence that quantitative measurement of the elements of these scattering matrices is possible in flow through systems.

Bilateral total hip and knee replacement in rheumatoid arthritis patients.

Between 1978 and 1983, 14 patients suffering from rheumatoid arthritis were treated by bilateral total hip and knee replacement. At the time of this follow-up study (32-92 months postoperatively) one patient had died of concomitant disease and was excluded. The postoperative results regarding pain relief, improvement in performing daily activities, and function were studied in the remaining 13 patients.

Osmotic response of lymphocytes measured by means of forward light scattering: theoretical considerations.

Recent data provide solid experimental evidence that increase in cell size of human lymphocytes, caused by osmotic stress, is not directly proportional to forward scattering intensity but rather is inversely proportional. Here, we provide arguments that this phenomenon can be quantitatively explained by means of a model based on a modified Rayleigh-Debye-Gans theory. As a consequence, the current view that forward scattering intensities can be used as a measure of gross cell size needs to be reconsidered.

Effect of ICS 205-930 (a specific 5-HT3 receptor antagonist) on gastric emptying of a solid meal in normal subjects.

The effects on gastric emptying of a solid meal of the specific 5-HT3-receptor antagonist ICS 205-930, 10 mg and 20 mg intravenously were assessed with a scintigraphic technique in 12 normals. The 50% emptying time was less, the lag phase was shorter and the post lag emptying rate was faster after 20 mg ICS 205-930 (p less than 0.02).

Bone healing during lower limb lengthening by distraction epiphysiolysis.

A study of limb lengthening by distraction epiphysiolysis in the rabbit tibia is presented. A special external distraction device was developed that allowed 10 mm lengthening of the leg. Bone formation in the elongated zone was studied by computed tomography and [99mTc] methylene diphosphonate (MDP) scintigraphy.

Effect of oral calcium and vitamin D on glucocorticoid-induced osteopenia.

Bone-loss in glucocorticoid-induced osteopenia is most evident in trabecular bone such as the vertebrae. Bone mineral content (BMC) measurements of the spine were prospectively studied, comparing the preventive effect of calcium (500 mg a day) and calcium plus Vitamin D (4000 IU on alternate days) during long-term corticosteroid treatment. A small increase in BMC was noted in both groups, but no differences between preventive calcium and calcium plus Vitamin D became evident.

Reversible harmless interruption of testicular blood supply in the ram.

An effective method of interrupting testicular blood flow temporarily and repeatedly in the ram has been developed. Blockade of flow has been achieved mechanically by an inflatable occluder placed around the testicular artery at the level of the spermatic cord. The effect of the blockade on total testicular blood supply was investigated using Doppler flowmetry and a percutaneous Xenon-133 injection method.

Radioiodinated Rhodamine-123: a potential cationic hepatobiliary imaging agent.

The labelling of the cationic dye Rhodamine-123 with 125I is described. The biodistribution of the iodinated Rhodamine-123 has been determined at different time intervals after intravenous injection into fasted rats. It turned out that the dye is predominantly cleared by the liver and discharged into the bile.

Monitoring fluoride therapy in osteoporosis by dual photon absorptiometry.

Dual photon absorptiometry (DPA) was used to evaluate changes in bone mineral mass in 108 osteopenic patients. Ninety were treated with fluoride and 18 served as controls. All osteopenic patients and 9 of the controls took calcium and vitamin D supplements.

On the mechanism of gallium accumulation in tumours. Isolation of N-hydroxypeptides.

With the use of A SEP-PAK Alumina N cartridge, peptide fractions containing the hydroxamate moiety have been isolated from tumour-tissue homogenate. It is therefore postulated that N-hydroxypeptides might play a role in the accumulation of gallium-67 in tumours. The biodistribution of several 67Ga-labelled hydroxamate peptide fractions is determined.

Evaluation of the renal scanning agent N-succinyldesferrioxamine B in dogs.

The mechanism of the excretion of 67 Ga-N-succinyldesferrioxamine B (SDF) was investigated in five healthy dogs. Comparison of the SDF clearance rates for whole blood and plasma as well as SDF renograms with those of 131 I-o-iodohippuric acid (OIH) and 111In-diethylenetriamine-pentaacetic acid (DTPA) revealed that SDF is cleared by glomerular filtration and not by an active tubular transport mechanism.

Synthesis and tumour-localizing properties of [18F]-5-fluorocytosine-arabinoside and [18F]-5-fluorocyclocytidine.

[18F]-5-fluorocytosine-arabinoside (2) and [18F]-5-fluorocyclocytidine (4) were prepared by reaction of [18F]-acetylhypofluorite with cytosine-arabinoside (1) or cyclocytidine (3) in acetic acid and were isolated in an overall radiochemical yield of 20% and 9%, respectively. The biodistribution of both radiopharmaceuticals was determined in melanoma bearing Syrian golden hamsters. It was found that 2 is a good tumour-localizing agent for pigmented and non-pigmented Greene melanoma.

Synthesis and biodistribution of [18F]-5-fluorocytosine.

[18F]-5-fluorocytosine was prepared by reaction of [18F]-acetylhypofluorite with cytosine in acetic acid and was isolated in an overall radiochemical yield of 20%. Tissue distribution studies in sarcoma-bearing rats indicated in vivo stability, limited tissue uptake and rapid urinary excretion.

The placenta as a substitute for cancerous models.

The tissue distribution of various radiopharmaceuticals was investigated in Rhabdomyosarcoma-bearing rats and in pregnant rats during the period of rapid foetal and placental growth (days 17-19 of pregnancy). The results indicate that with the radiopharmaceuticals tested the uptake in placental tissue followed closely the data obtained with tumour tissue in Rhabdomyosarcoma-bearing rats (1). We describe here the parallels between cell replication in the placenta and in malignant tumours and propose that the placenta merits more attention in the field of biomedical research.

The developing placenta in selecting potential radiopharmaceuticals for tumour-localizing properties: a simple in vivo pre-screening model.

The tissue distribution of various radiopharmaceuticals was investigated in rhabdomyosarcoma-bearing and in pregnant rats during the period of rapid foetal and placental growth (days 17-19 of pregnancy). The preliminary results indicate that with the radiopharmaceuticals tested the uptake in placental tissue followed closely the data obtained with tumour tissue in rhabdomyosarcoma-bearing rats.

N-Succinyldesferrioxamine B: a potential radiopharmaceutical for assessing renal function.

N-Succinyldesferrioxamine B was found to be cleared very fast by the kidneys. Since this compound can strongly chelate several metals, including the generator-produced isotopes 113mIn and 68Ga, 67Ga-N-succinyldesferrioxamine B (SDF) was tested as a substitute for 131I-o-iodohippuric acid (OIH) in the measurement of renal tubular secretion. In rats both compounds showed similar biodistribution patterns with a greater excretion rate of SDF.

The effects of chlorpromazine, mianserin and Org GC94 on reproductive function in the rat.

In the assessment of drug safety with respect to mammalian reproductive function chlorpromazine and two serotonin antagonists, mianserin (Org GB94 ) and Org GC94 were studied for their effects on ovulation and ovum transport. In addition, the effect of coitus on drug-induced ovulation inhibition was investigated. The compounds were intragastrically administered to Charles River CD rats in a single dose or in consecutive daily doses for one or two weeks.