We studied the presence of donor-specific T lymphocytes in explanted human cardiac valve allografts in vivo. From five of seven explants we propagated lymphocyte cultures in an interleukin-2 conditioned medium. Phenotyping revealed the presence of T-cell receptors in more than 95% of the lymphocytes obtained in each culture. Donor-specific cytotoxicity was demonstrated in three patients with known HLA status of the donor. Cytotoxicity was directed against only HLA class I in one patient, and against class I and/or class II in the others. These results indicate that donor-specific cellular reactivity can be induced by transplantation of human cardiac valve allografts.
Objective
To assess with Doppler colour flow imaging whether a brain‐sparing effect is present in all cerebral arteries of the circle of Willis in the small for gestational age fetus, to determine which cerebral flow velocity parameter is most discriminating in this pathological condition, and to relate this parameter to the umbilical artery pulsatility index.
Design
Prospective, cross‐sectional, matched case‐control study.
Setting
Academic department of obstetrics and gynaecology.
Subjects
Twenty‐eight small for gestational age fetuses and 28 normal controls at 24 to 38 weeks of gestation.
Interventions
Blood flow velocity waveforms from the umbilical and fetal intracerebral arteries were studied with Doppler colour flow imaging for measurement of peak systolic, end‐diastolic and time averaged velocities, and calculation of the pulsatility index.
Main outcome measures
Comparison of intracerebral and umbilical artery waveform parameters between small for gestational age fetuses and controls.
Results
Acceptable flow velocity waveforms were obtained in the intracerebral circulation in more than 85%. In small for gestational age fetuses, all intracerebral arteries displayed reduced downstream impedance. The end‐diastolic velocities of the middle and anterior cerebral artery are the most discriminative factors between small for gestational age fetuses and controls. The highest sensitivity was reached for the umbilical artery pulsatility index.
Conclusions
Doppler colour flow imaging allows easy identification of fetal intracerebral arterial vasculature. Whereas for the intracranial vasculature, the end‐diastolic blood flow velocities in the anterior and middle cerebral artery are the most sensitive parameters discriminating between small for gestational age and controls, umbilical artery pulsatility index remains the best indicator for the small for gestational age fetus.
Background: In patients on chronic hemodialysis leukocyte activation has been related to the impaired function of the immune system. In this study we investigated if the vitamin E-coated dialyzer membrane could reduce monocyte activation thereby improving cellular immunity. Methods: This hypothesis was tested in a prospective crossover trial in which 14 stable hemodialysis patients were switched from the baseline hemophane dialyzer to a vitamin E-coated and thereafter a polysulphone dialyzer membrane or vice versa. Results: Monocyte MHC class I, CD54 and ICAM-1 expression was significantly downregulated when a vitamin E-coated or polysulphone dialyzer was used. The use of a vitamin E membrane specifically decreased monocyte CD40 and CD86 expression. Lectin induced T cell proliferation increased with the use of the vitamin E-coated membrane as compared to polysulphone and hemophane dialyzers. Conclusion: Vitamin E-coated dialyzers induced a less-activated phenotype of monocytes and may improve cellular immunity.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.