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Biomedical subjects

M Ellis

Publications and source records attributed to M Ellis.

At least 145 records · Page 8Linked to original sources
PubMed1995

The influence of fibrinogen concentration on the development of vein graft stenoses.

OBJECTIVE: The aim of this study was to identify factors associated with the development of graft stenoses in the first year after bypass. DESIGN AND SETTING: Between January 1992 and April 1993, 75 consecutive patients undergoing distal vein bypass surgery were entered into a graft surveillance programme at Charing Cross Hospital. The grafts (n = 79) were surveyed by colour flow Doppler ultrasonography at 7 days, 3, 6, 9 and 12 months and the site of stenoses (> 50%) recorded. Position of the distal anastomosis, graft type (in situ or reverse) and clinical history were recorded. At the 3-month surveillance a blood sample was taken for the estimation of smoking markers, lipids and fibrinogen. RESULTS: The site of the distal anastomosis was to the suprageniculate popliteal in nine, infrageniculate popliteal in 32 and tibio/peroneal vessels in 38 cases. In the first month following bypass there were six deaths, giving a 30 day mortality of 7.5%, three patients were lost to follow up, seven grafts occluded, three were replaced by PTFE, four patients underwent amputation and one patient had a redo vein graft. In the remaining grafts 20/63 (32%) developed stenoses within the first year after bypass. The development of a graft stenosis was not associated with sex, diabetic status, site of distal anastomosis, graft type or serum lipids. Multiple regression analysis identified only one factor associated significantly with the development of vein graft stenosis: fibrinogen concentration (p = 0.003). Life table analysis showed that after 1 year only 46% of grafts remained free of stenoses in patients with above median fibrinogen concentrations compared with 84% of grafts in patients with below median fibrinogen concentrations, p = 0.009. CONCLUSIONS: Increased plasma fibrinogen concentration is a potent risk factor for the development of vein graft stenosis. These results prompt consideration of the role of fibrinogen in stimulating smooth muscle cell proliferation in the stenotic lesion.

Aged↗
PubMed1995

Monoclonal lymphocyte proliferation and bcl-2 rearrangement in essential mixed cryoglobulinaemia.

A patient with essential mixed cryoglobulinaemia (EMC) type II and hepatitis C virus (HCV) infection, in whom immunophenotypic and genotypic studies demonstrated a clonal proliferation of B lymphocytes, is described. Fluorescent in situ hybridization with probes to Ig heavy chain gene and to the oncogene bcl-2 demonstrated a translocation of bcl-2 to the immunoglobulin heavy chain locus on chromosome 14. A sharp rise in the level of the monoclonal IgM was associated with a second genetic aberration [t(8:22) (q24:q11)]. No other clinical evidence of disease progression could be demonstrated. Low grade lymphoproliferative disorder with typical cytogenetic abnormalities developed on the background of EMC and HCV. Clinical progression was associated with a second genetic abnormality involving the myc oncogene. It is possible that HCV chronic infection may indirectly influence oncogenes associated with lymphoma.

Adult↗
PubMed1995

Inhibition of influenza virus transcription by 2'-deoxy-2'-fluoroguanosine.

The nucleoside analog 2'-deoxy-2'-fluoroguanosine (2'-fluorodGuo) is phosphorylated by cellular enzymes and reversibly inhibits influenza virus replication in chick embryo cells within the first 4 h of infection. RNA hybridization studies revealed that primary and secondary transcription of influenza virus RNA were blocked at a compound concentration of 10 microM, but no inhibition of cell protein synthesis was seen even at high compound concentrations (200 microM). In vitro, the triphosphate of 2'-fluorodGuo is a competitive inhibitor of influenza virus transcriptase activity from disrupted virus, with a Ki of 1.0 microM. The cellular polymerases DNA polymerase alpha and RNA polymerase II were only weakly inhibited or were insusceptible to 2'-fluorodGTP. In kinetic studies with the influenza virus transcriptase, 2'-fluorodGTP, in the absence of GTP, blocked elongation of the virus RNA chain. Similarly, by using purified ribonucleoprotein complexes it was found that the addition of a single nucleotide of 2'-fluorodGTP to the virus RNA caused chain termination, which resulted in the blockage of further virus transcription. Furthermore, the specificity for influenza virus transcriptase was confirmed when the transcriptase from partially resistant virus was found to be 10-fold less susceptible to 2'-fluorodGTP (Ki = 13.1 microM).

Antiviral Agents↗
PubMed1994

Smoking and growth rate of small abdominal aortic aneurysms.

Smoking is an important risk factor for abdominal aortic aneurysm. Limiting the growth rate of small aneurysms has the potential to prevent them reaching a size at which surgical repair is considered. In 43 patients, with small aneurysms, growth rates were studied by serial ultrasound over 3 years. The median expansion rate of these small aneurysms was 0.13 cm per year. Growth rates were higher in those who continued to smoke (0.16 vs 0.09 cm per year in those who no longer smoked, p = 0.038). Higher growth rates were significantly correlated with the concentration of serum cotinine. Stopping smoking could reduce the growth rate of small abdominal aortic aneurysms.

Aged↗
PubMed1994

Desmoplastic malignant melanoma presenting with orbital involvement.

Desmoplastic malignant melanoma (DMM) is a rare variant of spindle cell melanoma. We report a case of DMM on the forehead secondarily involving the orbit. The diagnosis was based on light microscopic features, including prominent peripheral cell nest formation and spindle cell fascicles in densely collagenous stroma. Immunohistochemical studies showed strong uniform staining for S100 antigen throughout the tumour. It was negative for HMB 45, smooth muscle actin, desmin, cytokeratins and Type IV collagen. Electron microscopy showed neither melanosomes nor myelin figures. The clinical and histological characteristics of desmoplastic malignant melanoma, and its differential diagnosis of malignant schwannoma, are discussed. DMM has a poor prognosis, since it tends to invade deeply, recur locally and metastasize readily.

Aged↗
PubMed1994

Leiomyomatosis peritonealis disseminata. A report of two cases.

Leiomyomatosis peritonealis disseminata (LPD), also known as diffuse peritoneal leiomyomatosis, is characterized by the presence of multiple, small nodules scattered over the abdominopelvic viscera and peritoneum. These nodules are composed of benign smooth muscle cells. As shown in this report of two cases, the disorder occurs mostly in women of reproductive age and rarely in postmenopausal ones. LPD is a benign condition for which conservative management is indicated.

Adult↗
PubMed1993

Effect of growth promoters on pig muscle structural protein and proteolytic enzyme levels in vivo and in vitro.

To elucidate the biochemical mechanism by which the growth hormone porcine somatotrophin (PST) promotes skeletal muscle growth, we have determined the activity of a comprehensive range of protein catabolizing proteolytic enzymes and structural proteins (determined by analytical electrophoresis, SDS-PAGE) in longissimus dorsi muscle from control and PST treated pigs. There was no significant difference in the levels of muscle structural proteins, or in the activity of muscle proteolytic enzymes at point of slaughter in control or PST treated animals. Similarly, in post-mortem muscle proteolysis time course experiments at pH 5.5 or pH 7.5, there was no significant difference in the rate of structural protein degradation by endogenous muscle proteases (determined via SDS-PAGE) using muscle from control or PST treated animals. In addition, investigation of a range of beta-agonist related drugs (clenbuterol, salbutamol, pirbuterol, fenoterol) showed no effect (10(-4)-10(-8) M) in vitro on the activity of individual protease types in control muscle, or on the degradation rate of muscle structural proteins by endogenous proteases in time course experiments at pH 5.5 or pH 7.5.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenergic beta-Agonists↗
PubMed1993

Migration regions and interstate labor flows by occupation in the United States.

"This paper investigates the migration patterns of occupational groups [in the United States]. The results confirm previous analyses of the differences in movement behavior between occupations but, in addition, show that this variation is a function of the industrial sector of employment. The chief aim of the paper, however, is to uncover the geography of labor flows for different occupational groups using a principal components analysis of interstate flow matrices....Results indicate that migration regions vary by occupation and industry and we argue that these differences reflect job information flows and regional employment structure for various classes of labor." Data are from the Public Use Microdata Sample A taken from the 1980 census.

Americas↗
PubMed1993

Psychiatric aspects of epilepsy in childhood treated with carbamazepine, phenytoin or sodium valproate: a random trial.

Sixty-four new cases of childhood epilepsy were randomly assigned to either carbamazepine, phenytoin or sodium valproate, and were assessed with behavioural measures before medication and after one and six months of treatment. Those treated with carbamazepine and sodium valproate had minor behavioural difficulties after a month of treatment, but these did not persist. Mothers of the epileptic children had unusually high levels of anxiety and depression two months, on average, after epilepsy was diagnosed.

Adolescent↗
PubMed1993

A comparative analysis of alkylating agent and epipodophyllotoxin-related leukemias.

This review deals with the differences between leukemias--induced by alkylating agents as opposed to a "new form" of treatment related leukemia due to prior exposure to epipodophyllotoxins the latter having a short treatment--disease onset interval, absence of a MDS phase, a monocytic component and cytogenetic abnormalities involving the 11q23 band. The link between the existence of oncogenes or tumor suppressor genes located on the involved portion of chromosome 11 and the development of epipodophyllotoxin-related leukemia still needs to be examined. Alkylating agents--induced leukemias have a longer treatment--disease onset interval, have a prior myelodysplastic syndrome, and are most frequent myeloblastic or myelomonocytic in nature. Karyotype analysis reveals partial or complete deletion of chromosomes no. 5 or 7. This form of leukemia is highly resistant to treatment in the majority of cases. Some of the possible molecular mechanisms of leukemogenesis are discussed.

Alkylating Agents↗
PubMed1993

Second malignancies following treatment in non-Hodgkin's lymphoma.

Second malignancies represent an important iatrogenic complication of the treatment of hematologic and other neoplasms. In this review we summarize the literature relating specifically to malignancies developing in the wake of treated non-Hodgkin's lymphoma (NHL). In these patients, the risk of myelodysplastic syndrome (MDS) and acute non lymphocytic leukemia (ANLL) is reported to be increased 10-105 fold over that of the general population. Factors in the development of MDS and ANLL include basic defects in cellular immunity in NHL patients as well as treatment with alkylating agents and low dose total body irradiation. Biologically these secondary MDS and ANLLs are characterized by specific cytogenetic abnormalities and results of treatment are poor. Currently bone marrow transplantation offers the only potential cure. There is no clear statistical evidence that solid tumors occur more frequently after NHL. However, bladder carcinoma, in cyclophosphamide treated patients, and lung cancer have been reported by some to occur with an increased incidence. Further investigation of the molecular events leading to the occurrence of second malignancies in NHL patients and the role played by oncogenes and tumor suppressor genes in this process is still needed.

Actuarial Analysis↗
PubMed1993

Defense spending and interregional labor migration.

The impact of defense-related industry on labor migration within the United States is analyzed using census data for the period 1975-1980. The results "suggest that workers follow jobs in the defense industry, rather than vice versa, and indicate that a process of defense-related regional labor pool formation, amplified by interstate migration, adds to the volume of interregional labor flows."

Americas↗
PubMed1993

Health care crisis: the head and neck cancer patient and affordable health insurance.

In an evaluation of 30 patients with head and neck cancer, we found that 14 (46%) were uninsured at the time of diagnosis and 15 (50%) had yearly incomes below the poverty level. Tobacco and alcohol were identified as risk factors in 25 (83%) of the patients. These patients spent an average of $2,781 on carcinogenic agents yearly, increasing the risk of cancer 55 times that of the unexposed population, whereas the cost of a health insurance policy was $2,321 per year. To remedy the disparities and incongruities of this situation, we advocate patient education to influence behavioral change in these high-risk groups, a lowering of insurance rates, legal reform, and continued physician activism toward managing the current health care crisis.

Adult↗
PubMed1992

Insulin-like growth factor expression in breast cancer epithelium and stroma.

The insulin-like growth factors (IGFs) are mitogens for many cancer cell types. In breast cancer cells, IGF-I and IGF-II have both been shown to stimulate cell proliferation. However, IGF-I mRNA has not been found in human breast cancer cell lines, making it unlikely that IGF-I is commonly expressed as an autocrine growth factor for breast cancer cells. Nevertheless, IGF-I mRNA can be detected in breast cancer tissue samples, and in situ hybridization studies have shown that the message originates from the stromal cells adjacent to normal lobules. IGF-II, on the other hand, has been detected in some breast cancer cell lines. In the estrogen receptor positive cell line T47-D, IGF-II mRNA was induced by estradiol. Furthermore, transfection of an IGF-II expression vector into a previously estrogen-dependent cell line resulted in hormone independent growth. Thus, IGF-II can be expressed as an autocrine growth factor in some breast cancers and its expression may, in part, result in hormone independence. Finally, stromal cells obtained from breast tissues showed that IGF-I was commonly expressed in fibroblasts derived from non-malignant biopsy specimens, while IGF-II mRNA was detected in fibroblasts adjacent to malignant tissue. These studies suggest that IGF-II expression may be important in both autocrine and paracrine regulation of breast cancer cell growth.

Breast↗