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Biomedical subjects

E M Thompson

Publications and source records attributed to E M Thompson.

At least 73 records · Page 4Linked to original sources
PubMed1994

Gene expression of plasminogen activator inhibitor 1 in transplant kidneys complicated by renal vein thrombosis: a combined study by in-situ hybridization and immunohistochemistry.

In an attempt to understand the pathogenesis of renal vein thrombosis occurring early after renal transplantation, gene expression of plasminogen activator inhibitor-1 (PAI-1) was investigated by an in-situ hybridization technique. The cases examined were six transplant kidneys complicated by renal vein thrombosis, four 'normal' kidneys and five time-matched transplant kidneys not complicated by renal vein thrombosis but showing acute tubular necrosis, infection, or normal histology. The cell types expressing PAI-1 mRNA were also studied by combined in-situ hybridization and immunohistochemical double staining techniques. Our results showed that PAI-1 mRNA was expressed in transplant kidneys complicated by renal vein thrombosis but there was no detectable expression in 'normal' kidneys, nor in time-matched transplant kidneys not complicated by thrombosis. Double staining showed that PAI-1 mRNA was predominantly expressed by capillary endothelial cells, particularly around large- or medium-sized renal arteries and small nerves. Smooth-muscle cells in the wall of major or medium-sized renal arteries also showed positive expression of PAI-1 in three of six thrombosed transplants. However, endothelium in the major renal vein showed relatively little signal. The pattern was different from that in rejection. The possible relevance of these findings is discussed.

Adult↗
PubMed1993

Non-invasive prenatal diagnosis of osteogenesis imperfecta.

The main mode of non-invasive prenatal diagnosis of osteogenesis imperfecta (OI) is fetal imaging, either by radiography or detailed ultrasonography. Radiography is more of historical interest and ultrasonography is in practice virtually exclusively used for non-invasive second trimester diagnosis of OI. Both methods have also been reported later in pregnancy when diagnosis allows the most appropriate method of delivery to be planned. For example, a caesarean section can be avoided if the fetus is shown to have a form of OI associated with limited survival. Ultrasonography is useful mainly for prenatal diagnosis of the severe forms of OI, especially the perinatally lethal forms (Sillence type II) and to a lesser extent for the severe progressively deforming forms (Sillence types III and III/IV). For the milder varieties of OI (Sillence types I and IV), many cases will be missed by scans. Invasive methods of prenatal diagnosis of OI (principally chorion villous sampling) are used for families with the milder dominant forms of OI and in severe forms of OI in which the actual biochemical or molecular defect in type I collagen is known. Many cases of type II OI and a few of type III have now been reported which were detected by scans before 20 weeks gestation, the earliest being at 15 weeks, for type IIA OI. These include cases not only at genetic risk but also sporadic cases in which scans were done either routinely or for obstetric indications. The ultrasonic abnormalities which are found include reduced echogenicity, multiple fractures, and deformity of the long bones, ribs and skull.(ABSTRACT TRUNCATED AT 250 WORDS)

Delivery, Obstetric↗
PubMed1993

Localization of plasminogen activator inhibitor-1 production in inflamed appendix by in situ mRNA hybridization.

The peritoneum has been shown to possess fibrinolytic activity which is thought to play a role in the prevention of intra-abdominal adhesion formation. Recently inflamed peritoneal tissue has been shown to have reduced fibrinolytic activity secondary to increased levels of plasminogen activator inhibitor-1 (PAI-1). The aim of this study was to localize the production of PAI-1 in appendix tissue using in situ mRNA hybridization. Sections of normal and inflamed appendix were hybridized with a digoxigenin-labelled cDNA probe. PAI-1 production was localized to both mesothelium and serosal blood vessel endothelium in all inflamed appendix samples. Cell identities were confirmed using immunohistochemistry directed against mesothelial and endothelial cell markers. Staining was not seen on 1 probe following ribonuclease digestion). The identification of the cells expressing the PAI-1 gene in peritoneum increases our understanding of the pathophysiological changes in fibrinolytic activity which occur in inflammation and may lead to adhesion formation.

Appendicitis↗
PubMed1993

Expression and localization of plasminogen activator inhibitor 1 mRNA in transplant kidneys.

Fibrinolysis in renal transplant rejection has not been systematically investigated but is known to be impaired. By an in situ hybridization technique, we have studied gene expression of plasminogen activator inhibitor 1 (PAI-1) in human renal tissue showing severe acute vascular rejection (n = 8), clinically irreversible (chronic) vascular rejection (n = 3), mild vascular rejection (n = 8), parenchymal rejection (n = 4), 'normal' kidneys (n = 6), and non-rejecting kidneys (n = 6). The results showed that in 7/8 cases showing severe acute vascular rejection and in all three chronic vascular rejection cases, PAI-1 mRNA was expressed by endothelial cells of arterioles and arteries, and interstitial inflammatory cells but was not detectable in any other groups. The expression of PAI-1 was frequently associated with areas of haemorrhage. Expression of PAI-1 might be expected to promote thrombosis and ischaemia, the catastrophic consequence of severe vascular rejection. In irreversible chronic rejection, this seems to be the principal mode of action. However, our observation that there is expression of PAI-1 in areas of haemorrhage in severe acute vascular rejection may suggest an additional potentially protective role, if it were produced as a response to haemorrhage.

Adult↗
PubMed1993

Kivlin syndrome and Peters'-Plus syndrome: are they the same disorder?

Manifestations of Peters'-Plus syndrome include Peters' anomaly, short stature, small hands, mental retardation, abnormal ears and cleft lip and palate. 'Kivlin' syndrome is a similar disorder involving Peters' anomaly, short stature, short limbs, delayed development, facial clefting in some, ear abnormalities and a characteristic facial appearance attributable mainly to a 'cupid's bow' shape of the upper lip. Two new adult cases of Peters'-Plus are described, and follow-up information on a previously reported case of 'Kivlin' syndrome is presented. The two syndromes are reviewed and it is concluded that they are the same autosomal recessively inherited disorder, which we suggest should be called Peters'-Plus syndrome.

Abnormalities, Multiple↗
PubMed1993

Changes in pericardial morphology and fibrinolytic activity during cardiopulmonary bypass.

The presence of pericardial adhesions at resternotomy not only increases the operation time but also increases the risk of serious damage to the heart, great vessels, and extracardiac grafts. The reported prevalence of damage is 2% to 6%. The fibrinolytic activity of pericardial tissue may be a crucial factor in determining the extent of adhesion formation following primary operation. Ten patients undergoing cardiac operations were studied to assess the plasminogen activating activity of homogenates of pericardial tissue samples. Samples were taken at three times during the operation and the plasminogen activating activity was measured by means of a standard fibrin plate technique. Tissue-type plasminogen activator, urokinase-type plasminogen activator, plasminogen activator inhibitor-1, and plasminogen activator inhibitor-2 were also measured by means of enzyme-linked immunosorbent assays. Compared with its initial levels (median 2.06 IU/cm2, range 1.28 to 6.48 IU/cm2), the plasminogen activating activity of pericardial biopsy tissue was significantly reduced at 75 minutes (median 0.64 IU/cm2, range 0.12 to 2.44 IU/cm2, p < 0.01) and at 135 minutes (median 1.45 IU/cm2, range 0.12 to 4.39 IU/cm2, p < 0.05). The major plasminogen activator present was tissue-type plasminogen activator. Compared with its initial levels (median 2.34 ng/ml, range 1.03 to 6.42 ng/ml), subsequent tissue-type plasminogen activator values were also significantly reduced at 75 minutes (median 0.83 ng/ml, range 0.75 to 5.13 ng/ml, p < 0.005) and at 135 minutes (median 1.24 ng/ml, range 0.75 to 6.67 ng/ml, p < 0.05). Low levels of urokinase-type plasminogen activator were found in 5 of 10 patients. However, neither plasminogen activator inhibitor-1 nor plasminogen activator inhibitor-2 was detected. Examination with a light microscope showed both increasing pericardial mesothelial damage and increasing features of acute inflammatory changes with time. This study shows that plasminogen activating activity is present in pericardial tissue and that tissue-type plasminogen activator is the major plasminogen activator. The observed inflammatory changes and concomitant damage to the pericardial mesothelium, and the significant reductions in pericardial tissue-type plasminogen activator and plasminogen activating activity seen during cardiac operations, may be important factors contributing to the early development of pericardial adhesions.

Adult↗
PubMed1992

Apparent cleidocranial dysplasia associated with abnormalities of 8q22 in three individuals.

Cleidocranial dysplasia is an autosomal dominant, generalised skeletal disorder characterised by variable clavicular hypoplasia, frontal bossing, multiple Wormian bones, and delayed eruption of the teeth. The gene locus for this syndrome has not yet been assigned. Three individuals with manifestations of cleidocranial dysplasia associated with rearrangements of chromosome 8q22 are described. The evidence presented suggests that the gene for cleidocranial dysplasia may be located on chromosome 8q in humans in a region showing homology to mouse chromosome 3.

Adult↗
PubMed1991

Problems in day care surgery.

In-patient admission represents a failure of a day care service. The hospital records of 105 patients transferred from the day ward to the in-patient wards were studied retrospectively. Of 2,039 patients treated in the day care ward, 105 (5%) required in-patient admission over a 12 month period. Of these 105 admissions, 17% did not fulfil the criteria for day care patients, 46% had surgical problems, and 35% anaesthetic-associated problems. The in-patient admission rate could be reduced by improved out-patient selection of cases, use of a separate day care theatre, increased use of local anaesthetic techniques, reduction in the use of parenteral opioids, the use of simple oral analgesics or non-steroidal anti-inflammatory agents as pre-emptive analgesia and a wider use of propofol as an induction agent which provides superior recovery from anaesthesia.

Ambulatory Surgical Procedures↗
PubMed1990

Vargula hilgendorfii luciferase: a secreted reporter enzyme for monitoring gene expression in mammalian cells.

The small marine ostracod crustacean, Vargula hilgendorfii, produces a bright blue luminous secretion which is ejected into seawater. The luminescence is due to a simple enzyme-catalyzed reaction involving only luciferase, luciferin (substrate), and molecular oxygen. Thus, V. hilgendorfii luciferase (VL) should be useful as a reporter enzyme in studies of gene expression in mammalian cells. Expression plasmids consisting of VL cDNA (vl) linked to the promoters simian virus 40 early region, Rous sarcoma virus long terminal repeat, human elongation factor, or mouse granulocyte colony-stimulating factor were introduced into a series of mammalian cell lines. Following transfection, VL activities in cell extracts and culture media were determined by a rapid light emission assay with V. hilgendorfii luciferin. Parallel experiments were carried out with the chloramphenicol acetyltransferase (CAT)-encoding gene. In all cell lines tested, VL was secreted, allowing the reporter activity to be determined directly from a small aliquot of the culture medium. The results indicate that the secreted VL enzyme is superior to CAT, firefly luciferase, and bacterial luciferase as a convenient and versatile indicator of gene expression in mammalian cells.

Animals↗
PubMed1990

The incidence of delta F508 CF mutation, and associated haplotypes, in a sample of English CF families.

Data are presented for delta F508 screening and KM19/XV2c haplotype analysis of 195 cystic fibrosis (CF) chromosomes from the British Caucasian population. We report the frequency of delta F508 in this group to be 80% and find pronounced disequilibrium between the deletion and the KM 2, XV 1 haplotype. Haplotype analysis of 71 normal chromosomes is also presented. We report one individual who had meconium ileus and who does not have the delta F508 mutation on either chromosome.

Cystic Fibrosis↗
PubMed1990

Kinetics of enteroendocrine cells with implications for their origin: a study of the cholecystokinin and gastrin subpopulations combining tritiated thymidine labelling with immunocytochemistry in the mouse.

Evidence for a common endodermal stem cell has been derived from kinetic studies in mouse small intestine which indicate that the turnover characteristics of endocrine cells are similar to those of other cell lineages (columnar and goblet cells). We have used continuous tritiated thymidine labelling and peptide immunocytochemistry on resin embedded semithin sections, a combination of techniques which have not been used before in the small intestine. Our data show that the turnover time for endocrine cells in the small intestine is 10 days, considerably longer than the four days suggested by previous studies, although for columnar and mucous cell lineages, turnover rates are similar to the published literature. In the stomach, the turnover time was very slow indeed (of the order of 45-60 days). These results show that endocrine cells do not share turnover characteristics with the other cell types and suggest that they constitute a kinetically distinct cell population independent of the other cell lineages. These data are not consistent with a common stem cell origin for gut endocrine cells.

Animals↗
PubMed1989

Cloning and expression of cDNA for the luciferase from the marine ostracod Vargula hilgendorfii.

The marine ostracod Vargula hilgendorfii ejects luciferin and luciferase into seawater to produce a bright luminous cloud. The light is due to the oxidation of luciferin, an imidazopyrazine compound, by molecular oxygen, catalyzed by luciferase. The mechanism of the reaction has been studied extensively and the 60 kcal/mol required for the blue emission have been shown to be derived from the oxidation of luciferin via a dioxetanone intermediate, in which the excited state oxyluciferin bound to luciferase is the emitter. However, only limited information is available regarding the properties of the enzyme. This paper reports the cloning and sequence analysis of the cDNA for Vargula luciferase and the expression of the cDNA in a mammalian cell system. The primary structure, deduced from the nucleotide sequence, consists of 555 amino acid residues in a single polypeptide chain with a molecular weight of 62,171. Two regions of the enzyme show significant amino acid sequence homology with an N-terminal segment of the photoprotein aequorin. The Vargula luciferase gene, which contains a signal sequence for secretion, should be well suited as a reporter in studies of gene expression.

Amino Acid Sequence↗
PubMed1989

X linked mental retardation: a family with a separate syndrome?

Four males with X linked mental retardation are described. Manifestations similar to those seen in the FG syndrome include severe constipation, tall, broad foreheads, hypotonia, and cowlicks of the hair line, but no individual patient had all the features of the syndrome and none had macrocephaly. The facial appearance was distinctive but different from that seen in the FG syndrome. The cases are presented in order to discuss the phenotypic limits of the FG syndrome and to consider the need to separate other distinct but similar entities.

Female↗
PubMed1989

Kyphomelic dysplasia.

A case of kyphomelic dysplasia is reported in a boy followed up over three years. The most striking feature of this recessively inherited generalised bone dysplasia is marked angulation of the femora, associated with short stature, bowing and shortening of other long bones, metaphyseal changes in infancy, flared ribs, small thoracic cage, and platyspondyly. The good prognosis regarding motor and intellectual development in this condition is stressed and the association with cleft lip and palate is described for the first time.

Bone Diseases, Developmental↗