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Biomedical subjects

S C Robson

Publications and source records attributed to S C Robson.

At least 163 records · Page 9Linked to original sources
PubMed1994

The effect of a tumour necrosis factor antibody on the regenerative response after partial hepatectomy in rats.

In this study we investigated the effect of tumour necrosis factor (TNF) on the regenerative response after partial hepatectomy. Adult male rats were injected intravenously with an antibody to TNF immediately after partial hepatectomy. Animals were sacrificed at 0, 24, 48, 72 and 96 h postoperatively. Hepatic thymidine kinase (TK) activity, liver weight to body weight (LW/BW) ratio, and mitotic index (MI) were used as indices of hepatic regeneration. The rats treated with TNF-Ab had significantly lower levels of TK activity in the liver at 24 h postoperatively compared to the saline treated animals. Furthermore the peak hepatic TK activity was delayed to 48 h in the rats treated with TNF-Ab. The mitotic indices and LW/BW ratios in the TNF-Ab- and saline-treated animals were similar. These data suggest that TNF potentiates the regenerative response after partial hepatectomy.

Animals↗
PubMed1994

Hydralazine boluses for the treatment of severe hypertension in pre-eclampsia.

OBJECTIVE: To audit the use of bolus hydralazine for control of severe hypertension within a protocol for the management of severe pre-eclampsia. DESIGN: A retrospective review. SETTING: Three UK teaching hospitals. SUBJECTS: Seventy consecutive women who received hydralazine for the treatment of sustained severe hypertension. Twenty-five women had more than one episode of hypertension amounting to a total of 109 treatment episodes. INTERVENTION: Intravenous bolus hydralazine 5 mg, repeated every 15 min to reduce the mean arterial pressure to < 125 mmHg. MAIN OUTCOME MEASURES: Change in mean arterial pressure in response to bolus hydralazine, fetal condition, as assessed by heart rate changes and umbilical arterial pH at delivery, and protocol violations were analysed. RESULTS: Mean arterial pressure fell by 12 mmHg (95% CI 10-14) after the first bolus, 9 mmHg (95% CI 6.5-12) after the second bolus and 5 mmHg (95% CI 1-10) after the third bolus. Eighty-two (75%) episodes were managed strictly according to the protocol; of these, blood pressure was controlled by bolus therapy alone in 89%. Of the 27 instances in which the protocol was not adhered to, blood pressure was not controlled in four. There were no significant differences in the incidence of cardiotocographic abnormalities or umbilical acidaemia in the women treated before delivery (n = 36) compared with those in whom treatment was first initiated afterwards (n = 34). CONCLUSIONS: Hydralazine given in 5 mg boluses is a safe and effective method of treating severe hypertension in pre-eclampsia. Despite clear management guidelines, protocol violations were common, and in 4% of treatment episodes these were potentially serious resulting in failure to control blood pressure.

Adult↗
PubMed1994

Prediction of perinatal morbidity at term in small fetuses: comparison of fetal growth and Doppler ultrasound.

OBJECTIVE: To compare fetal growth assessed by ultrasound (change in standard deviation score of abdominal circumference and estimated fetal weight) during the third trimester with predelivery ultrasound measurements of fetal size and Doppler measurements from the umbilical and fetal arteries in order to predict suboptimal perinatal outcome in small babies at term. DESIGN: Prospective observational study. SETTING: Day assessment unit in a university hospital. SUBJECTS: One hundred and four consecutive women with a clinical suspicion of a small fetus during the third trimester confirmed by ultrasound (abdominal circumference below the 10th centile) and ultimately delivered at term. MAIN OUTCOME MEASURES: Acidaemia at birth, fetal distress requiring emergency caesarean section in labour, admission to the neonatal intensive care unit. RESULTS: Ninety-four babies (90%) weighed less than the 10th centile and the incidence of suboptimal perinatal outcome was 27%. The largest areas under the receiver operating characteristic curves for suboptimal perinatal outcome were obtained with the change in standard deviation score of abdominal circumference and estimated fetal weight, and the ratios of aortic/middle cerebral and renal/middle cerebral pulsatility index. Although low, the odds ratios of the change in estimated fetal weight standard deviation score and the Doppler ratios were significantly different from zero. CONCLUSION: Ultrasound assessment of fetal growth and predelivery fetal Doppler pulsatility index ratios were superior to predelivery estimates of fetal size and umbilical artery pulsatility index in predicting suboptimal perinatal outcome in small fetuses delivering at term, although the clinical value of such a prediction may be limited.

Acidosis↗
PubMed1994

Umbilical vessel wall fatty acids after normal and retarded fetal growth.

In a prospective observational study, the fatty acid content of human umbilical artery and vein wall phospholipids was determined in fetuses classified according to their change in abdominal circumference during the third trimester. Three groups were identified: appropriate for gestational age (AGA; 24 infants) and small for gestational age (SGA; 38 infants) with normal antenatal growth rate, and SGA with fetal growth retardation (22 infants). The venous linoleic acid (18:2 omega 6) content (expressed as a percentage of the total fatty acids identified) was greater in growth retarded SGA fetuses (3.5 (0.6)%) than in SGA fetuses with a normal growth rate (3.1 (0.5)%) and AGA fetuses (3.0 (0.5)%), whereas the venous contents of eicosatrienoic (20:3 omega 6) and docosahexaenoic acid (22:6 omega 3) were lower. In growth retarded SGA fetuses, the venous and arterial 20:3 omega 6 content correlated with the change in abdominal circumference. In SGA fetuses with a normal growth rate, lower contents of arterial 18:2 omega 6 and 22:6 omega 3 were associated with a smaller change in abdominal circumference and birth weight. Different metabolic derangements appear to underly normal and subnormal growth rate in SGA fetuses, suggesting that different strategies of dietary intervention may be required to aid fetal growth and reduce the sequelae of fetal growth retardation.

Abdomen↗
PubMed1994

Distribution of hepatic nerve fibers in liver diseases.

Autonomic hyperactivity with increased cardiac output and other manifestations occurs in patients with both cirrhosis and noncirrhotic portal hypertension. The role of the disordered hepatic autonomic innervation in the mediation of these abnormalities is unknown. We have studied the hepatic nerve network and associated extracellular matrix proteins in patients with portal hypertension (alcoholic cirrhosis, extrahepatic portal vein obstruction, idiopathic portal hypertension), and in patients without portal hypertension (alcoholic hepatitis, psoriasis before and after treatment with methotrexate, a potentially hepatotoxic drug) by immunohistochemical methods. Histologically normal liver biopsies from patients undergoing abdominal surgery served as normal controls. Hepatic parenchymal nerves were absent in cirrhotic nodules and were depleted in the fibrotic strands of alcoholic cirrhotic livers. In alcoholic hepatitis, where clinical and histological features associated with portal hypertension were absent, nerve fibers were increased around the portal vein branches. Similar increase was also noted in liver biopsies from patients with noncirrhotic portal hypertension. Increased numbers of nerve fibers around portal veins were demonstrated in psoriatics, particularly those treated with methotrexate. Immunohistochemical studies of extracellular matrix proteins revealed apparent inverse relationships between innervation and fibronectin deposition with direct relationships to laminin staining. The association of nerve network with portal hypertension and cellular inflammation was inconsistent.

Autonomic Nervous System↗
PubMed1993

The introduction of external cephalic version at term into routine clinical practice.

External cephalic version (ECV) at > or = 37 weeks' gestation in suitable women with breech presentation was introduced in 1991 as a new management option at a University Teaching Hospital. After 16 months, the policy was audited by analysing a prospectively collected database of women offered ECV at term and by a retrospective review of all breech deliveries during the same period. A total of 52 women had ECV attempted with an immediate success rate of 46%. Four other cases had undergone spontaneous version by the time they attended for ECV. Of the remaining 72 breech deliveries, 49 were known to be breech and were not offered ECV; 39 of these had no contraindication (28% failure to offer ECV). Of the breech presentations, 22 remained undiagnosed until labour (18% of total study group). These results suggest that ECV at term can be introduced safely and without difficulty, with a strict protocol. Whilst the overall impact of ECV at term in clinical practice may be limited, if some vaginal breech deliveries and caesarean sections can be avoided it is a useful addition to the antenatal management of individual women with breech presentation.

Breech Presentation↗
PubMed1993

Neonatal morphometric indices of fetal growth: analysis of observer variability.

Measurements of triceps and subscapular skinfold thickness, mid-arm circumference (MAC), head circumference (HC) and crown-heel length were performed by two observers in 30 healthy neonates. Intra-observer standard deviation for all measurements, calculated using one-way analysis of variance, was small and similar for each observer. Inter-observer variability was assessed using limits of agreement. There were small, systematic, differences between observers for measurements of triceps skinfold thickness and crown-heel length, and for calculated ponderal index (PI). When related to respective published reference ranges, the 95% prediction intervals for subscapular (-0.51, 0.68 mm) and triceps (-0.65, 0.29 mm) skinfold thicknesses were less than those for the MAC/HC ratio (-2.1, 1.9) and PI (-0.23, 0.28). The results indicate that skinfold thickness measurements are a more robust measure and, therefore, may be of greater value in the assessment of neonates with suspected fetal growth retardation.

Anthropometry↗
PubMed1993

Fibrin and fibrinogen degradation products with an intact D-domain C-terminal gamma chain inhibit an early step in accessory cell-dependent lymphocyte mitogenesis.

Although the low molecular weight degradation products of fibrinogen (FgDP) and fibrin (FbDP) are known to inhibit lymphocyte blastogenesis, the effect of purified macro-molecular FgDP and FbDP (molecular weight, 90 to 200 Kd) is unclear. We have examined the effect of these latter FgDP and FbDP and find that products that contain the D domain inhibit lymphocyte proliferation in response to T-cell mitogens, allogeneic mononuclear leukocytes, and anti-CD3 in vitro. Plasmic digestion of D1 in the absence of calcium with removal of the C-terminal end of the gamma chain or disruption of the gamma-gamma C-terminal cross-link site of D-dimer (DD) by puffadder venom (PAV-D) abrogates their inhibitory potential. Prior incubation of monocytes with DD or D1 inhibits subsequent lymphocyte transformation. Binding studies with radiolabeled DD and PAV-D confirm that monocytes interact only with DD. This specific binding may be competitively inhibited by monoclonal antibodies to CD11b/CD18 or by peptide analogues of the C-terminal gamma chain of fibrinogen that mimic the adhesion recognition site of integrins. We postulate that DD and D1 bind to CD11b/CD18 on adherent monocytes and modulate lymphocyte activation. These products are typically present in the plasma of patients with disseminated intravascular coagulation with sepsis and could therefore influence inflammatory processes in vivo.

Antigen-Presenting Cells↗
PubMed1993

An investigation of fetal growth using serial ultrasound data.

Serial ultrasonic measurements were performed in 67 Caucasian fetuses from 20 weeks' gestation until term to derive reference standards for abdominal circumference (AC) and estimated fetal weight (EFW). The variances of both AC and EFW increased with gestational age. Four mathematical models (linear, quadratic, Gompertz and Rossavik) were fitted to the log(10)(AC) and log(10)(EFW) data from each fetus using least squares regression analysis. The standard deviations of the residual error were greatest for the linear model. The linear model also overestimated the final log(10)(AC) while the linear, Gompertz and Rossavik models all overestimated the final log(10)(EFW) when these data were omitted from the fitting process. The individual quadratic constants were, therefore, used to produce 67 individual growth curves. Values of log(10)(AC) and log(10)(EFW) for each fetus at exact gestational ages between 20 and 40 weeks were derived by interpolation; the mean and standard deviation values were then used to derive centile ranges for abdominal circumference and estimated fetal weight. These standards should prove useful in the assessment of fetal growth.

Journal Article↗
PubMed1993

Unusual lymphangioma observed prenatally in a 45,X fetus.

We present a case of a large frontal lesion, suspected on antenatal ultrasound to be a cephalocele. The cardiac anatomy was abnormal and fetal blood sampling showed a 45,X chromosome constitution. Postmortem examination proved this to be a lymphangioma and confirmed the presence of a cardiac defect. We suggest that this lymphangioma represents an unusual manifestation of monosomy X and discuss the importance of doing chromosome analysis in the presence of such a lesion which is of similar appearance as a cephalocele.

Adult↗
PubMed1993

Immunological similarity between the 170 kD amoebic adherence glycoprotein and human beta 2 integrins.

Amoebiasis is an important cause of morbidity and mortality in developing countries. Virulence of Entamoeba histolytica depends on the trophozoite's being able to bind to colonic epithelium; binding is mediated by the 170 kD subunit of a 260 kD lectin. We found, by microcytofluorometry and western blotting studies, that this 170 kD subunit protein shares an epitope with human beta 2 integrins--a subfamily of cell-surface glycoproteins expressed exclusively on leucocytes and involved in many adhesive and signalling interactions. The immunological similarity between these proteins may explain the trophozoite's ability to bind to and invade colonic epithelium.

Amebiasis↗
PubMed1993

Disordered hemostasis in extrahepatic portal hypertension.

To assess the contribution of naturally occurring portal-systemic shunts to the coagulopathy of patients with liver disease, we studied laboratory parameters of hemostasis in 20 adult patients with extrahepatic portal hypertension, secondary to portal vein thrombosis, that had resulted in variceal bleeding. All extrahepatic portal hypertension patients had normal liver function and histological appearance. None had any evidence of preexisting coagulation disorders, and none had bled or undergone sclerotherapy in the 6 mo before study. Age- and gender-matched groups of 20 healthy individuals and 20 stable patients with cirrhosis and portal hypertension who had a history of variceal bleeding served as controls. Both patient groups had thrombocytopenia consistent with hypersplenism and portal hypertension. Prothrombin international normalized ratio (extrahepatic portal hypertension, 1.3 +/- 0.12; cirrhosis, 1.7 +/- 0.2; control, 1.02 +/- 0.06; p < 0.05) and partial thromboplastin time ratios (extrahepatic portal hypertension, 1.12 +/- 0.1; cirrhosis, 1.26 +/- 0.2; controls, 1.01 +/- 0.03; p < 0.05) were significantly prolonged in both patient groups. Extrahepatic portal hypertension and cirrhotic patient groups had significantly increased levels of serum total fibrin(ogen)-related antigen (extrahepatic portal hypertension, 818 +/- 150 ng/ml; cirrhosis, 454 +/- 52 ng/ml; controls, 124 +/- 7.3 ng/ml; p < 0.05), fibrin monomer (extrahepatic portal hypertension, 168.8 +/- 16.9 ng/ml; cirrhosis, 115.6 +/- 11.1 ng/ml; controls, 19.7 +/- 0.4 ng/ml; p < 0.05) and D-dimer (extrahepatic portal hypertension, 118 +/- 9.6 ng/ml; cirrhosis, 129 +/- 10 ng/ml; controls, 53.2 +/- 1.6 ng/ml; p < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Ultrasonic fetal weight estimation: analysis of inter- and intra-observer variability.

Standard ultrasound measurements were performed by two observers in 40 third-trimester fetuses. Observers were blinded to the results of the measurements. Estimated fetal weight (EFW) was calculated using two published formulae. The intra-observer standard deviation for EFW, assessed using one-way analysis of variance, was < 75 g for both observers. The 95% prediction intervals for inter-observer comparisons of EFW, calculated using the limits of agreement method, were -187.3 g to 139.8 g, and -159.9 g to 124.3 g, using the two formulae. The results suggest that measurements of EFW are reproducible. The prediction interval is comparable to the weekly fetal weight increment in normal fetuses.

Analysis of Variance↗