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Biomedical subjects

M Rees

Publications and source records attributed to M Rees.

At least 91 records · Page 5Linked to original sources
PubMed1995

Computed tomographic portography in preoperative imaging of hepatic neoplasms.

Preoperative selection of suitable patients for liver resection is dependent on the quality of radiological imaging. Computed tomography (CT) identifies approximately 70 per cent of lesions. Computed tomographic arterial portography (CTAP) during contrast enhancement of the liver via the portal vein may be superior to conventional CT. Preoperative CTAP was evaluated in 60 patients with hepatic neoplasm (48 having colorectal metastases) who subsequently underwent laparotomy. The preoperative images were compared with intraoperative palpation, intraoperative ultrasonography and histology of the resected liver. Fifty-six patients (93 per cent) underwent partial hepatectomy. The detection rate sensitivity for CTAP was 110 of 116 lesions in the 56 patients (95 per cent) and for intraoperative ultrasonography was 114 of 116 (98 per cent). CTAP correctly identified all lesions found at histology in 50 of 56 (89 per cent) resected specimens. At laparotomy four of 60 patients (7 per cent) were inoperable; two of these had been predicted to be so by this technique. CTAP correctly identifies and locates the majority of hepatic tumours, particularly metastases, and is the procedure of choice for selection of suitable candidates for partial hepatectomy.

Adult↗
PubMed1995

Exclusion of the locus for autosomal recessive pseudohypoaldosteronism type 1 from the mineralocorticoid receptor gene region on human chromosome 4q by linkage analysis.

Pseudohypoaldosteronism type 1 (PHA1) is an uncommon inherited disorder characterized by salt-wasting in infancy arising from target organ unresponsiveness to mineralocorticoids. Clinical expression of the disease varies from severely affected infants who may die to apparently asymptomatic individuals. Inheritance is Mendelian and may be either autosomal dominant or autosomal recessive. A defect in the mineralocorticoid receptor has been implicated as a likely cause of PHA1. The gene for human mineralocorticoid receptor (MLR) has been cloned and physically mapped to human chromosome 4q31.1-31.2. The etiological role of MLR in autosomal recessive PHA1 was investigated by performing linkage analysis between PHA1 and three simple sequence length polymorphisms (D4S192, D4S1548, and D4S413) on chromosome 4q in 10 consanguineous families. Linkage analysis was carried out assuming autosomal recessive inheritance with full penetrance and zero phenocopy rate using the MLINK program for two-point analysis and the HOMOZ program for multipoint analysis. Lod scores of less than -2 were obtained over the whole region from D4S192 to D4S413 encompassing MLR. This provdes evidence against MLR as the site of mutations causing PHA1 in the majority of autosomal recessive families.

Alleles↗
PubMed1994

Linkage analysis of idiopathic generalised epilepsy in families of probands with Juvenile Myoclonic Epilepsy and marker loci in the region of EPM 1 on chromosome 21 q: Unverricht-Lundborg disease and JME are not allelic variants.

The locus for Unverricht-Lundborg disease, EPM 1, has recently been mapped to chromosome 21q22.3. A locus, EJM 1, predisposing to idiopathic generalised epilepsy in families of probands with juvenile myoclonic epilepsy has been localised to chromosome 6p by evidence of linkage to the HLA region. However, segregation analysis suggests a two-locus model for JME and evidence has been obtained for genetic heterogeneity within the JME/IGE phenotype. EPM 1 was therefore investigated as a candidate locus in the set of families segregating for IGE and JME which do not show linkage to markers on chromosome 6p. Linkage analysis was carried out in 25 families using three microsatellite DNA markers around the EPM 1 gene region using different models of inheritance. Multipoint linkage analysis provided definite exclusion for 20cM around PFKL, the closet linked marker to EPM 1, under three out of four models tested. These results strongly suggest that the EPM 1 gene is not linked to the phenotype expressed in these families, and therefore that Unverricht-Lundborg disease and juvenile myoclonic epilepsy are not allelic variants.

Adolescent↗
PubMed1994

Frequent normal allele loss and maternal origin of the mutation shown by DNA homoduplex analysis in a severely affected patient with adenomatous polyposis coli.

An atypically high frequency of loss of heterozygosity at chromosome 5q22 in small adenomas from a severely affected new mutation patient with adenomatous polyposis coli was recently reported. DNA homoduplex analysis has now been used to show that the deletion in the adenomas extends to include the APC locus and that the normal allele is lost. These data also prove the maternal origin of the mutation.

Adenomatous Polyposis Coli↗
PubMed1994

The epilepsies.

There is good evidence for a genetic causation of a significant proportion of the human epilepsies. These genetic epilepsies include a large number of rare mendelian syndromes in which epilepsy usually occurs as part of a more complex neurological phenotype, and the more common familial epilepsies in which seizures occur in isolation but inheritance is not mendelian. The molecular basis of these epilepsies is entirely unknown. The current revolution in genetics and neuroscience is, however, providing methods for the molecular genetic analysis of epilepsy. Two principal strategies exist. The first, positional cloning, requires localization of the disease genes by linkage analysis followed by analysis of transcripts within the disease-gene region. The second, candidate gene analysis, comprises direct screening of cloned genes which may on theoretical grounds have a role in epilepsy. At present, two epilepsy genes have been localized by linkage analysis: that for benign familial neonatal convulsions to chromosome 20, and that for progressive myoclonic epilepsy of Unverricht and Lundborg to chromosome 21. Linkage analysis of non-mendelian epilepsies is more difficult, but may be feasible with the generation of high-resolution linkage maps of the human genome. A number of plausible candidate genes for the epilepsies have now been cloned, including in particular the ligand-gated and voltage-gated ion channels. An understanding of the genetic epilepsies at a molecular level will provide new precision in diagnosis and genetic counselling, and may allow new strategies for pharmacological control of seizures.

Animals↗
PubMed1994

Effects of antiplatelet therapy with indobufen or aspirin-dipyridamole on graft patency one year after coronary artery bypass grafting.

Saphenous vein coronary artery bypass graft patency can be increased by antiplatelet therapy. Aspirin plus dipyridamole are effective but are associated with tolerability problems. Indobufen is a possible alternative antiplatelet agent that may be better tolerated. A prospective, randomized, double-blind, parallel-group study was undertaken to compare the efficacy and safety of indobufen 200 mg twice daily with aspirin 300 mg thrice daily plus dipyridamole 75 mg thrice daily in preventing occlusion of autologous saphenous vein coronary artery bypass grafts. A total of 803 patients were randomized in the study, of whom 552 had a follow-up coronary angiogram approximately 1 year after operation. All anastomoses were patent in 56% of indobufen-treated patients and 59% of aspirin-dipyridamole recipients (p = 0.384). The percentage of all anastomoses patent was 82% in the indobufen group and 83% in the aspirin-dipyridamole group (p = 0.297). Mean postoperative blood loss was significantly less in the indobufen group (p = 0.043). Patients who received indobufen also had significantly fewer adverse events considered to be treatment-related compared with aspirin-dipyridamole recipients (p = 0.02). At the doses tested indobufen was as effective as aspirin plus dipyridamole in preventing occlusion of saphenous vein grafts and was better tolerated. Because indobufen was associated with less postoperative blood loss it may be used before operation in coronary artery bypass grafting.

Adolescent↗