A proposal to standardize terminology for weak D antigen.
Explore the source record for details and available documents.
Biomedical subjects
Publications and source records attributed to D M Davies.
Explore the source record for details and available documents.
Of 446 deaths among serving and retired British Airways pilots between 1966 and 1989, 411 were analysed using the Proportional Mortality Ratio (PMR) technique. After removal of the predictable excess of aircraft accidents, excesses of cancer (PMR 1.31) and other accidents (1.60) were balanced by deficits in diseases of the circulatory (0.83) and respiratory (0.49) systems. While lung cancer was close to expectation (1.10), consistent excesses were shown in all analyses for malignant melanoma (6.68), cirrhosis of the liver (2.88), colon cancer (2.30) and brain/CNS cancer (2.68). Consideration of these ratios in relation to pilots' lifestyle and occupation leads to the conclusion that the brain/CNS cancer excess must be studied further.
The kinetics of the dithionite reduction of calf liver microsomal cytochrome b5, both free in solution and bound to dimyristoyl phosphatidylcholine vesicles, are consistent with electron transfer between SO2- and the exposed haem edge of the protein. The vesicle membrane does not hinder the approach of SO2- to the site of electron transfer on the protein. In 0.01 M-Tris/HCl buffer, pH 8.1, ket (25 degrees C), delta H et and delta S et are estimated to be 1.44 x 10(6) M-1.s-1, 7.8 kJ.mol-1 and -92.3 J.K-1.mol-1 respectively. The cytochrome exhibits an acid dissociation, pKa 9.3 +/- 0.3, and the rate of electron transfer from dithionite to the high-pH form is about one-third of that to the neutral-pH form. The effect of ionic strength on the kinetics is consistent with a reaction between like-charged species and is discussed in terms of a number of theoretical models. In systems comprising cytochrome b5 and negatively charged vesicles, the effect of increasing the charge density of mixed dimyristoyl phosphatidylcholine/dicetyl phosphate vesicles and of increasing the concentration of dicetyl phosphate vesicles is to lower the rate of electron transfer from dithionite to the haem moiety of the cytochrome. With vesicles of high charge density, however, the kinetics are complicated by vesicle-induced conformation changes of the cytochrome.
Revascularised grafts of jejunum and colon have been used to reconstruct the cervical oesophagus in dogs. The grafts were examined at 2 months to assess their morphological and morphometric behaviour in their new position in the oesophagus. The colonic grafts appeared to adapt completely, while the jejunal ones manifest persisting mucosal changes attributable to their new environment.
Explore the source record for details and available documents.
Changes in the u.v.-visible absorption spectrum of cytochrome b5 which occur upon addition of dicetyl phosphate, dimyristoyl phosphatidic acid (DMPA), or mixed DMPA/dimyristoyl phosphatidylcholine vesicles are consistent with haem transfer from the cytochrome to the membrane via an intermediate haemoprotein species. The effects of vesicle charge and concentration on the kinetics of haem transfer are discussed.
Pulsed Doppler ultrasound assessment of blood flow was performed in the fetal aorta and umbilical arteries of 41 patients with hypertension in pregnancy. Patients were grouped according to severity of the hypertension and the presence or absence of chronic hypertension. Doppler abnormalities were seen in two patients with chronic hypertension, both of whom delivered small for gestational age infants. Only one patient with mild to moderate preeclampsia had abnormal aortic Doppler assessment and was also delivered of a small for gestational age infant. The highest number of abnormal Doppler waveforms in both fetal aorta and umbilical artery were found in patients with severe preeclampsia. Abnormalities were detected more frequently in the fetal aorta than in the umbilical artery. Doppler assessment was often abnormal before a nonstress test or biophysical profile. The number of abnormal Doppler values correlated with perinatal outcome in patients with severe preeclampsia.
Our experience of phalloplasty using the radial forearm flap in five transsexual cases is reported. The results are disappointing due to the high incidence of complications. We had partial success in two cases, both complicated by a fistula, and complete failure in three cases due to vascular thrombosis.
Penile reconstruction remains a difficult surgical problem. To produce a phallus capable of erection and with a water-tight urethra to the tip has not been solved satisfactorily even by the introduction of free flap transfers. We present a method used in four cases, three transsexuals and one pseudohermaphrodite, in which a phallus was successfully constructed using the deep inferior epigastric flap.
The use of an innervated lateral trapezius flap to allow movement of the paralysed face is described. Five cases are presented, all of whom achieved some facial movement postoperatively. The place of this technique in the armamentarium of procedures for facial reanimation is discussed.
An experimental animal model was set up to study the comparative behaviour of revascularised transplants of colon and jejunum used to reconstruct the cervical oesophagus. Age, sex and size matched greyhound dogs were used in the study. An investigation of the physiological behaviour of the graft mucosa was carried out at 8 weeks using the mucosal specific activity of the enzyme Na+K+ATPase. The findings demonstrate a clear depression in the functional behaviour of the jejunal graft mucosa, while the colonic graft mucosa remained biochemically unchanged. The significance of these findings is discussed, and the conclusion drawn that they support the hypothesis that colon makes a more stable and functionally superior free graft than jejunum when replacement of the cervical oesophagus is required.
Explore the source record for details and available documents.
The reconstruction of the cervical esophagus and the hypopharynx by revascularized bowel grafts has become a well-recognized treatment option and often is the method of first choice. Problems described by several protagonists of the standard revascularized jejunal graft have caused us to hypothesize that the colon provides both a suitable alternative and a solution to these problems. Experimental work in dogs demonstrates clear functional differences between colon and jejunum as free esophageal grafts. Video-fluoroscopic and manometric assessment of the two types of graft show that structurally and functionally the colon integrates into the new position in the esophagus better than does the jejunum.
The reconstruction of the cervical oesophagus and the hypopharynx by revascularised bowel grafts has become a frequently described treatment option. Problems with the standard jejunal grafts have led us to suggest that the colon provides a suitable alternative. Experimental work in dogs demonstrates clear functional differences between colon and jejunum as free oesophageal grafts, and shows how structurally and functionally the colon integrates into the new position in the oesophagus better than the jejunum.
Explore the source record for details and available documents.