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Biomedical subjects

H Ring-Larsen

Publications and source records attributed to H Ring-Larsen.

At least 37 records · Page 2Linked to original sources
PubMed1993

Cyclosporin A treatment in primary biliary cirrhosis: results of a long-term placebo controlled trial.

BACKGROUND: Effective treatment for primary biliary cirrhosis (PBC) resulting in slower progression and improved survival remains elusive. Cyclosporin A (CyA), which has been so effective in preventing human allograft rejection, has shown promise in small numbers of patients in early studies. METHODS: Three hundred forty-nine patients with PBC were randomized to receive CyA, 3 mg.kg-1.day-1, or placebo in a multicenter study with follow-up for 6 years. The end point was death or liver transplantation. RESULTS: Cox multivariate analysis showed time from entry to death or transplantation was significantly prolonged (by up to 50%) in the CyA-treated group. Liver-related mortality was also significantly lower. However, a univariate analysis of survival showed no statistical differences between the two groups. Biochemical liver indices deteriorated more slowly in the CyA-treated group, but serum creatinine concentration was elevated > 150 mumol/L in 9%, necessitating permanent discontinuation in half of these. A reduction in the dose of CyA was required in 11% because of hypertension. CONCLUSIONS: CyA has some therapeutic potential in primary biliary cirrhosis, providing blood pressure and renal function are closely monitored.

Adult↗
PubMed1992

Identification of patients with hereditary haemochromatosis by magnetic resonance imaging and spectroscopic relaxation time measurements.

A total of 4302 healthy blood donors were screened for elevated serum ferritin and transferrin saturation. Fifteen had increased serum ferritin at a follow-up examination. Five relatives of these donors also entered the study. Eleven patients had elevated liver iron concentrations, while five had normal liver iron concentrations. The R2 relaxation rate in the liver was first measured with a conventional multi-spin-echo imaging sequence, and then by a volume-selective spectroscopic multi-spin-echo sequence, in order to achieve a minimum echo time of 4 msec. No correlation was found between the relaxation rate R2 and the liver iron concentration, when R2 was calculated from the imaging data. Multi-exponential transverse relaxation could be resolved when the spectroscopic sequence was used. A strong correlation between the initial slope of the relaxation curve and the liver iron concentration was found (r = 0.90, p < 0.001). Signal intensity ratios between liver and muscle were calculated from the first three echoes in the multi-echo imaging sequence, and from a gradient echo sequence. A strong correlation between the logarithm of the signal intensity ratios and the liver iron concentration was found. Although both spectroscopic T2 relaxation time measurements and signal intensity ratios could be used to quantify liver iron concentration, the gradient echo imaging seemed to be the best choice. Gradient echo imaging could be performed during a single breath hold, so motion artifacts could be avoided. The accuracy of liver iron concentration estimates from signal intensity ratios in the gradient echo images was about 35%.

Biopsy↗
PubMed1992

Estimated central blood volume in cirrhosis: relationship to sympathetic nervous activity, beta-adrenergic blockade and atrial natriuretic factor.

The estimated central blood volume (i.e., blood volume in the heart cavities, lungs and central arterial tree) was determined by multiplying cardiac output by circulatory mean transit time in 19 patients with cirrhosis and compared with sympathetic nervous activity and circulating level of atrial natriuretic factor. Arterial norepinephrine level, an index of overall sympathetic nervous activity (3.08 nmol/L in patients vs. 1.36 nmol/L in controls; p < 0.01) was negatively correlated (r = -0.54, p < 0.01) with estimated central blood volume (mean = 23 ml/kg in patients vs. 27 ml/kg in controls; p < 0.05). Similarly, renal venous norepinephrine level (an index of renal sympathetic tone; 4.26 nmol/L in patients vs. 1.78 nmol/L in controls; p < 0.01) was inversely correlated with estimated central blood volume (r = -0.53, n = 18, p < 0.02). No significant correlation could be established between arterial atrial natriuretic factor level (8.9 pmol/L in patients vs. 9.6 pmol/L in controls; not significant) and estimated central blood volume. Hemodynamic values were subsequently modified with oral propranolol (80 mg). During beta-adrenergic blockade, the mean estimated central blood volume was not altered significantly, except in six patients who exhibited decreases in mean arterial blood pressure (85 to 69 mm Hg; n = 6) and decreases in mean estimated central blood volume (23.2 to 20.6 ml/kg; n = 6, p < 0.05). Slight increases were observed in mean right atrial pressure (2.2 to 3.7 mm Hg; n = 14, p < 0.05); this change was positively correlated with the change in estimated central blood volume (r = 0.44, n = 14, p = 0.06).(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenergic beta-Antagonists↗
PubMed1991

Screening for haemochromatosis: prevalence among Danish blood donors.

Hereditary haemochromatosis is an autosomal recessive disease that is genetically expressed by excessive accumulation of iron in the tissues, resulting in cirrhosis, diabetes mellitus, cardiomyopathy and hypogonadism. As the disease may be diagnosed before the appearance of symptoms, and prevented by repeated phlebotomies, there are strong implications for adoption of a screening procedure. Determinations of transferrin saturation (TS) and serum ferritin concentration (SF) were used to screen 4302 blood donors, who were selected for follow-up studies if they fulfilled any of the following three criteria: (i) TS greater than or equal to 0.7; (ii) TS greater than or equal to 0.5 together with SF greater than or equal to 150 micrograms l-1; (iii) SF greater than or equal to 300 micrograms l-1. A total of 58 subjects who fulfilled at least one of these criteria were reinvestigated, after which 18 individuals still fulfilled at least one criterion. Fifteen subjects having SF greater than or equal to 300 micrograms l-1 were offered liver biopsy and thirteen of these accepted. In one individual, no stainable iron was detected, and two subjects did not fulfil the previously established diagnostic criteria for the diagnosis of hereditary haemochromatosis. Ten subjects who had a high TS and liver iron grade 2-4 according to Bassett were classified accordingly as homozygotes. On the basis of these results, the prevalence of haemochromatosis in Denmark was estimated to be 0.0037-0.0046.

Adult↗
PubMed1991

Chronic evolution of acute hepatitis B: the significance of simultaneous infections with hepatitis C and D. Copenhagen Hepatitis Acuta Programme.

Seventy-six of 77 consecutive patients with hepatitis B surface antigen (HBsAg)-positive acute hepatitis were reevaluated using anti-hepatitis C virus (HCV), anti-hepatitis D virus (HDV), and IgM anti-hepatitis B core (HBc) testing. Anti-HCV and/or anti-HDV was found in 32 patients (42%). The presence of these markers was significantly associated with intravenous drug abuse (p less than 10(-6). Sixty-nine patients were IgM anti-HBc-positive, of whom two (3%) (95% confidence limits, 1-12%) became chronic HBsAg carriers with histologically verified chronic liver disease; both were anti-HCV and anti-HDV-negative. Among the remaining 67 IgM anti-HBc-positive patients 8 had HBV and HDV co-infection, 3 had HBV and HCV co-infection, and 1 had HBV, HCV, and HDV co-infection. Twenty-two had evidence of preceding or past HCV infection; two developed chronic active hepatitis in spite of HBsAg clearance. Seven patients with IgM anti-HBc negative. One was a chronic HBsAg carrier with HDV superinfection. One had subclinical acute HBV infection and became a chronic HBsAg carrier. In a further two patients reactivation of replication in a chronic HBV infection could not be disregarded. Three patients could not be classified; all had acute recent onset of symptoms, cleared HBsAg within 6 months, but lacked IgM anti-HBc. It is concluded that HCV and HDV superinfections in HBV carriers mimicking acute HBV infection with chronic evolution are rarely encountered in the present population in spite of high frequency of both HCV and HDV markers.

Adolescent↗
PubMed1990

Early appearance of antibodies to hepatitis C virus in community acquired acute non-A, non-B hepatitis is associated with progression to chronic liver disease. The Copenhagen Hepatitis Acuta Programme.

24 consecutive patients (14 females; median age 36, range 18-77) with liver biopsy proven acute non-A, non-B hepatitis (NANBH) were assayed for antibodies to hepatitis C virus (HCV). 14 (58%) were positive initially or during follow-up. Three patients were positive within 4 weeks following onset of symptoms and 7 patients in a serum sample obtained 4-8 weeks after clinical onset. Seroconversion was documented in 7/8 patients in paired sera from the acute phase of the disease. Anti-HCV was detected in 6% and 13% of control patients with acute hepatitis A and toxic hepatitis. NANBH in 6/14 patients (43%) with anti-HCV progressed to chronic liver disease (CLD). In contrast none of the anti-HCV negative patients developed CLD (p = 0.02). In addition, 2 anti-HCV positive patients developed fulminant and fatal hepatitis. The predominant route of HCV transmission was intravenous drug abuse. It is concluded that hepatitis may be ascribed to HCV infection in more than half of patients with community aquired NANBH, that seroconversion occurs in the majority within 8 weeks following onset of symptoms and that seropositive individuals often progress to CLD.

Adolescent↗
PubMed1989

[Effect of posture on the diuretic treatment of decompensated cirrhosis and heart failure].

The diuretic effect of the supine position was evaluated in six patients with cirrhosis and ascites and six with congestive cardiac failure. All patients received 1 mg bumethanide intravenously and were randomly assigned to either bed rest in the supine position or normal daily activity in the upright position for the next six hours. The diuretic response was similar in patients with heart failure and cirrhosis, and was significantly greater in the supine than in the upright position: mean 1,133 v 626 ml/6 h (p less than 0.01). The natriuresis was similarly greater during recumbency: mean sodium 96 v 45 mmol (mEq)/6 h (p less than 0.01), and the excreted potassium in six hours was similar in both postures. The glomerular filtration rate was 100 and 66 ml/min (p less than 0.01) and the heart rate 76 and 83 beats/min (p less than 0.05) in the supine and upright positions, respectively. Plasma concentrations of noradrenaline, renin, and aldosterone rose significantly during the upright position. The results suggest that the attenuated response to intravenous bumethanide in the upright position and during normal daily activity may be due to the activation of several, homoeostatic mechanisms which may reduce the excretion of water and salt.

Adult↗
PubMed1989

Reduced central blood volume in cirrhosis.

The pathogenesis of ascites formation in cirrhosis is uncertain. It is still under debate whether the effective blood volume is reduced (underfilling theory) or whether the intravascular compartment is expanded (overflow theory). This problem has not yet been solved because of insufficient tools for measuring the central blood volume. We have developed a method that enables us to determine directly the central blood volume, i.e., the blood volume in the heart cavities, lungs, and central arterial tree. In 60 patients with cirrhosis and 16 control subjects the central blood volume was assessed according to the kinetic theory as the product of cardiac output and mean transit time of the central vascular bed. Central blood volume was significantly smaller in patients with cirrhosis than in controls (mean 21 vs. 27 ml/kg estimated ideal body weight, p less than 0.001; 25% vs. 33% of the total blood volume, p less than 0.0001). The lowest values (18 ml/kg) were found in patients with gross ascites and a reduced systemic vascular resistance. In patients with cirrhosis central blood volume was inversely correlated to the hepatic venous pressure gradient (r = -0.41, p less than 0.01), and the total blood volume was inversely correlated to the systemic vascular resistance (r = -0.49, p less than 0.001), the latter being significantly reduced in the patient group. Patients with cirrhosis apparently are unable to maintain a normal central blood volume. This may be due to arteriolar vasodilation, portosystemic collateral flow, or sequestration of fluid in the peritoneal cavity, or any combination thereof. The present results indicate that central circulatory underfilling is an integral part of the hemodynamic and homeostatic derangement observed in cirrhosis.

Adult↗
PubMed1989

Continuous infusion of tracer norepinephrine may miscalculate unidirectional nerve uptake of norepinephrine in humans.

In order to evaluate uptake kinetics of norepinephrine (NE) in different tissues, a catheterization study was performed in control subjects (n = 6) and patients with enhanced sympathetic nervous activity (cirrhosis, n = 12) during constant intravenous infusion of L[3H]norepinephrine ([3H]NE) for 75 minutes. In spite of a higher NE spillover from kidneys in patients compared with controls (82 vs. 49 ng/min, p less than 0.01), renal extraction ratios of [3H]NE were similar in the two groups (0.33 vs. 0.32, NS), and no significant change was observed during the time of infusion. In contrast, liver-intestine extraction ratios of [3H]NE decreased significantly and equally with infusion time in patients (from 0.57 to 0.44, p less than 0.01) and controls (from 0.59 to 0.46, p less than 0.01). This was observed despite the fact that spillover of NE from this vascular bed was observed only in patients with cirrhosis and not in controls (41 vs. -5 ng/min, p less than 0.02). In the lower limb, net release of NE was similar in patients and controls, and extraction ratios of [3H]NE decreased almost equally with infusion time (from 0.35 to 0.30, p less than 0.01 and from 0.40 to 0.24, p less than 0.1, respectively). Whole-body clearance of [3H]NE decreased over time in patients (-6%, p less than 0.01) and controls (-20%, p less than 0.01), but significant difference was not observed between the groups. We conclude that failure to attain a steady state with respect to [3H]NE removal was demonstrated in areas of large tissue volume relative to blood flow.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗