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Biomedical subjects

M Bowen

Publications and source records attributed to M Bowen.

At least 73 records · Page 4Linked to original sources
PubMed1985

Changes in plasma fibronectin during donor apheresis and therapeutic plasma exchange.

Changes in plasma levels of the opsonic glycoprotein fibronectin were studied during machine apheresis in 32 healthy plasma donors and 18 patients undergoing a total of 86 therapeutic plasma exchanges. Donation of 500 ml of plasma at 3-monthly intervals produced a 10% immediate decrease in plasma fibronectin with no evidence of a long-term affect on levels of this protein. One plasma volume exchange with fibronectin-poor plasma protein fraction produced subnormal plasma fibronectin levels in 98% of post-exchange samples. Efficiency of exchange was significantly lower in patients with paraproteinaemia, probably reflecting increased plasma volume in such patients. Daily plasma exchange produced progressive depletion of plasma fibronectin (index of recovery 0.68) whereas levels were maintained close to the initial value with longer exchange intervals, except in the more severely ill patients. Reduction of plasma fibronectin by plasma exchange may increase susceptibility to infection and reduce the efficacy of this procedure when the object of exchange is to reverse reticuloendothelial blockade.

Adult↗
PubMed1985

Changes in plasma fibronectin during allogeneic bone marrow transplantation.

Plasma fibronectin concentrations were measured serially in nine patients undergoing allogeneic bone marrow transplantation. Concentrations were reduced by conditioning treatment and episodes of bacterial infection. Acute graft versus host disease may exacerbate or prolong this process. Reduced plasma fibronectin concentrations impair the function of the mononuclear phagocyte system and the maintenance of capillary endothelial integrity and may thus contribute to the morbidity and mortality in patients undergoing bone marrow transplantation.

Adolescent↗
PubMed1984

The diagnosis of pleural effusions--are cancer markers clinically helpful?

We submitted 83 consecutive patients with pleural effusion to routine clinical investigation; 57 were diagnosed as malignant, 18 as benign, and 8 were not diagnosed. Pleural fluid and serum were analysed for carcinoembryonic antigen (CEA), acid glycoprotein (AGP), antichymotrypsin (ACT), C-reactive protein (CRP), alpha 2-pregnancy associated glycoprotein (alpha 2-PAG) and ferritin. Multivariate discriminant analysis was performed on the results of the protein measurements. CEA and ACT values in serum and fluid were found to give a good discriminating function between the benign and malignant groups. The use of such an analysis, in a clinical context, is discussed.

Adult↗
PubMed1984

Relation of alpha 2-macroglobulin and other antiproteases to the clinical features of acute pancreatitis.

alpha 2-macroglobulin is probably the most important of the antiproteases in plasma. In this study, the relationships of plasma alpha 2-macroglobulin to the clinical features of acute pancreatitis as well as to plasma levels of other antiproteases, immunoglobulins, and immunoreactive trypsin, were investigated in 55 patients with acute pancreatitis. The mean level of alpha 2-macroglobulin in 395 plasma samples from the patients was 2.12 g/liter compared with 2.41 g/liter in 29 healthy subjects and 2.93 g/liter in 17 patients with septicemia. Plasma levels were lower in 12 patients with severe pancreatitis than in 43 with mild attacks, and the lowest levels in three fatal attacks were less than half the mean of the normal range. Lowest levels were recorded at a mean time of 3 days after admission in the patients with mild attacks, at 5 days after admission in the patients with severe attacks, and 9 days after admission in those with fatal attacks. In contrast, plasma levels of the alpha 1-proteinase inhibitor antichymotrypsin and C-reactive protein increased to above normal levels during the attack, significantly more so in severe compared with mild attacks. Plasma levels of IgA, IgG, and IgM remained within the normal range or were increased. In patients with severe pancreatitis, plasma levels of immunoreactive trypsin remained elevated for longer than in those with mild attacks although there was little initial difference in the levels. These data suggest that decreasing levels of alpha 2-macroglobulin during the course of acute pancreatitis are due to a specific mechanism and unrelated, for the most part, to any generalized effect of pancreatitis on protein synthesis. The formation of rapidly cleared complexes between alpha 2-macroglobulin and active proteases is the most tenable explanation for the depletion of plasma levels, but the clinical significance of the changes remains unclear.

Acute Disease↗
PubMed1984

C reactive protein: an aid to assessment and monitoring of acute pancreatitis.

An evaluation of C reactive protein as an indicator of the progress of acute pancreatitis has been made, and the data have been compared with the information given by the white cell count, erythrocyte sedimentation rate, and temperature and by two antiproteases--alpha 1 protease inhibitor and alpha 1 antichymotrypsin. The main value of C reactive protein is to provide a guide to the severity of the inflammation and to increase clinicians' awareness of the patient's enhanced risk of developing pancreatic collections when the C reactive protein concentration remains high (greater than 100 mg/l) at the end of the first week of the illness. In this respect C reactive protein concentrations are superior to white cell count, erythrocyte sedimentation rate, and temperature and the concentrations of antiproteases.

Acute Disease↗
PubMed1984

Plasma beta-2-microglobulin and fibronectin levels in beta-thalassaemia.

The plasma beta 2-microglobulin (beta 2-MG) levels in 118 children with thalassaemia were investigated. The mean level was higher than in healthy children. A significant increase of beta 2-MG was associated with hypersplenism (3.14 +/- 0.6 mg/l). The beta 2-MG levels appeared to reflect reticuloendothelial system activity but were not related to iron overload. Fibronectin levels were generally lower than in healthy adults; profound chronic fibronectin depletion was not accompanied by an increased liability to infection.

Adolescent↗
PubMed1983

Fighting fire.

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Disaster Planning↗
PubMed1983

Plasma fibronectin in myeloproliferative disorders and chronic granulocytic leukaemia.

A significant reduction of plasma fibronectin levels was found in polycythaemia vera and myelofibrosis, the lowest levels being found in patients with marked splenomegaly. Plasma fibronectin concentration was normal in essential thrombocythaemia, and only modest reduction was seen in chronic granulocytic leukaemia in either controlled chronic phase or blast cell crisis. In a patient with myelofibrosis, the plasma fibronectin rose from less than 100 mg/l to 177 mg/l after splenectomy. Possible explanations include increased consumption of plasma fibronectin in the expanded mononuclear phagocyte system present in the liver and spleen, reduced hepatic synthesis, and the clearance of circulating immune complexes. Low plasma fibronectin concentrations may increase susceptibility to infection.

Adult↗
PubMed1983

Low fibronectin in portal hypertension.

We have measured plasma fibronectin in 28 patients with well-compensated chronic liver disease, 4 patients with non-cirrhotic portal hypertension and 6 patients who have undergone shunt surgery for the relief of portal hypertension and splenectomy. 17 patients with portal hypertension had significantly lower levels of fibronectin (207 +/- 54; mean +/- SD) compared with 15 patients without portal hypertension (315 +/- 75, p less than 0.001) and the 6 patients who had undergone shunting and splenectomy (330 +/- 66, p less than 0.001). We suggest that in patients with portal hypertension and splenomegaly, low levels of fibronectin might result from increased consumption by the enlarged spleen.

Fibronectins↗
PubMed1983

The diagnosis of acute pancreatitis: enhanced sensitivity from an ELISA assay of lipase.

An enzyme linked immunosorbent assay (ELISA) for human pancreatic lipase was compared, for diagnostic sensitivity, to a chromogenic assay of total plasma amylase in 37 patients with acute pancreatitis. Data from patients were related to a control group of 38 patients with gastrointestinal disease but without pancreatic diseases. During the first 24 hours of admission, lipase was elevated 131 standard deviations (SD) above the mean of the control range compared to 25 SD for amylase (p less than 0.001). When amylase fell to within the control range (less than 531 iu/l) lipase was still elevated at a mean of 11 SD above the control mean. In patients followed for longer, lipase usually remained above normal for at least ten days, whereas amylase lay within 1 SD of the mean of the control samples in most plasma samples after 4 days. These data show that lipase is considerably more sensitive than total amylase for the diagnosis of acute pancreatitis.

Acute Disease↗
PubMed1982

Limitations of using pregnancy-associated alpha-2 glycoprotein as a tumour marker.

The development of a new enzyme-linked immunoassay for pregnancy-associated alpha-2 glycoprotein (alpha 2-PAG) has provided an opportunity to reassess the value of this protein as a tumour marker. Serum samples from 800 healthy individuals and patients with various benign and malignant diseases were assayed. There was a very wide range of alpha 2-PAG levels in normal females (1- greater than 100 mg/l), and although the levels found in normal males were lower and better defined, this intrinsic variation between individuals makes a single determination in a tumour-bearing patient meaningless. Also, the levels of alpha 1-PAG in patients with advanced cancer were not significantly different from levels in localized cancer, benign disease or even healthy controls, and furthermore, levels before and after successful cancer treatment did not show a significant change. Our results therefore indicate that alpha 2-PAG is unsuitable for use as a tumour marker as there was no apparent relationship between the levels of alpha 2-PAG and either tumour burden or response to treatment.

Adolescent↗