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Biomedical subjects

F Wells

Publications and source records attributed to F Wells.

At least 19 recordsLinked to original sources
PubMed1995

Clinical experience with a collagen impregnated woven Dacron graft.

Vascular grafts continue to evolve. Recent developments have been aimed at decreasing porosity, increasing strength of prosthesis, increasing ease of handling and suturing and optimising flow characteristics. This study describes results with a recently developed collagen impregnated polyester prosthesis Hemashield Woven Double Velour, which does not require pre-clotting. Between January 1988 and December, 1991 such prostheses were used in 90 patients at Papworth Hospital. Fifty-eight, were used to replace the ascending aorta, 10 for the arch of the aorta and 28 for the descending aorta seven of whom were for coarctation and four for traumatic transections. In 60 cases the underlying disease was a dissected or ruptured aorta requiring emergency operation. There were 66 survivors with X-ray and CT follow-up of 6-52 months. Median blood loss was 630 ml range 380-1800 ml. There was no leakage from any of the grafts during surgery despite full perioperative heparinisation. For emergency/elective operations (N = 60/30) early mortality was 25%/10% (15/3) and late mortality 5%/6.6% (3/2). Of 15 patients who had interposition grafts for Type A dissection CT scans at 5-47 months showed one with chronic dissection proximal to the repair and 11 with persistent distal dissection. There was no evidence of late bleeding, seroma impaired healing or thickened neointima formation. It is concluded that there are no clinical disadvantages associated with collagen impregnation to set against the notable convenience of initial impermeability.

Adult↗
PubMed1992

Massive hemothorax due to enlarging arteriovenous fistula in pregnancy.

A 37-year-old woman with hereditary telangiectasia suffered a life-threatening hemothorax due to an enlarging pulmonary arteriovenous malformation in pregnancy. This was treated by emergency right lower lobectomy and excision of arteriovenous malformations in the right middle and upper lobes, with no postoperative complications, and the subsequent delivery of a normal infant. Women with hereditary telangiectasia contemplating pregnancy should be screened for the presence of PAVM to anticipate complications.

Adult↗
PubMed1989

Frequency and extent of allelic loss in the short arm of chromosome 3 in nonsmall-cell lung cancer.

DNA was prepared from tumour and normal tissue from 48 patients representing all common histological types of nonsmall-cell lung cancer. Using eight DNA probes, which detect nine restriction enzyme fragment length polymorphisms (RFLP) on chromosome 3, we established that among the 44 informative patients 32 had lost alleles on the short arm of one of their copies of chromosome 3. Of these 32, at least 13 had also lost alleles on the long arm of chromosome 3, suggesting that the whole chromosome might be lost. For one patient, cytogenetic analysis indicated that the mechanism of allelic loss was reciprocal translocation followed by chromosomal loss of one of the reciprocal products. Two patients with allelic loss distal to the D3S3 locus (which maps to 3p13-14) retained heterozygosity at that locus. These results indicate that loss of alleles on the short arm of chromosome 3 is a common event in lung tumours of the nonsmall-cell type, that this loss occurs by a variety of chromosomal mechanisms, and that the minimally deleted region is 3p13-14----3pter.

Alleles↗
PubMed1989

Effect of donor heart damage on survival after transplantation.

Evaluation of the functional condition of the heart prior to its removal from the donor or after transport to the recipient is difficult. Biopsies of the myocardium allow serial assessments to be made throughout this period, but suffer from the disadvantage that the average analysis of biopsies has only a tenuous connection with physiological function. Quantitative birefringence measurements (QBM), on the other hand, assess the ability of myocardial fibres to respond to ATP and calcium and have been shown to correlate well with measurements of cardiac function (P less than 0.001). A prospective study of myocardial biopsies before excision, after transport and again after transplantation, using quantitative birefringence measurement of biopsies of the heart has recently been completed. These studies have shown evidence of impaired myocardial function in 73 (43%) of 172 donor hearts studied prior to excision, with a further 27% showing significant deterioration during storage and transport to the recipient. Biopsy assessments therefore indicated that at the moment of implantation, only 30% of the donor hearts were normal. Functional assessment of the biopsies by QBM correlated with early clinical outcome of transplantation (P less than 0.001). Longer term follow-up of the recipients (up to 5 years) has shown that the mortality of recipients of hearts with impaired function before transplantation is significantly increased (44% of 120) compared with that of recipients of undamaged hearts (6% of 52, P less than 0.001).

Biopsy↗
PubMed1987

Lymphoid cells in the spleens of woodchuck hepatitis virus-infected woodchucks are a site of active viral replication.

Lymphoid cells were purified from the spleens of 15 woodchucks and examined for the presence of woodchuck hepatitis virus (WHV). Lymphoid cells from the spleens of eight of eight chronically infected animals contained high levels of WHV RNA and DNA. A 100-fold lower level of WHV DNA was found in the spleen from one of five animals that had recovered from acute WHV infections 2 years before this analysis. No WHV nucleic acids were observed in either of two uninfected animals. WHV DNA patterns in the lymphoid cells from the spleens of the chronically infected animals, which included the presence of single-stranded DNA and RNA-DNA hybrid molecules, were identical to those observed in WHV-infected liver. WHV DNA in these cells was present in intact, 27-nm core particles which also contained the endogenous DNA polymerase activity. These results indicate that the spleen is a site of active WHV DNA replication and is most likely a major source of WHV-infected cells in the circulating lymphoid cell population.

Animals↗