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Biomedical subjects

K Brinch

Publications and source records attributed to K Brinch.

13 recordsLinked to original sources
PubMed2000

Central and systemic haemodynamic effects of terlipressin in portal hypertensive patients.

AIMS/BACKGROUND: Cirrhotic patients exhibit a hyperdynamic and hyporeactive circulation with central hypovolaemia which may influence the course of the disease. As terlipressin, a vasopressin analogue, may modify systemic haemodynamics in these patients, the aim of the present study was to assess the acute effects of terlipressin on central and systemic haemodynamics. METHODS: Sixteen patients with alcoholic cirrhosis and portal hypertension had their systemic, central, and splanchnic haemodynamics determined at baseline and after a blind randomised bolus infusion (2 mg) of terlipressin/placebo. RESULTS: After terlipressin, the arterial blood pressure and the systemic vascular resistance increased by 26% and 61%, respectively (both p<0.001), and the cardiac output, heart rate, and arterial compliance decreased by 18%, 11%, and 32%, respectively (all p<0.001). The central circulation time increased by 36% (p<0.001), whereas the central and arterial blood volume only increased by 4% (p= 0.07). As expected, both portal pressure and hepatic blood flow decreased (17% and 29%, both p<0.001). The decrease in portal pressure after terlipressin was significantly related to the increase in systemic vascular resistance (r=-0.52, p<0.05) and the central circulation time (r=-0.80, p<0.0001). CONCLUSIONS: Terlipressin significantly attenuates the hyperdynamic circulation in portal hypertensive patients without a further contraction of the central and arterial blood volume. The systemic haemodynamic response to terlipressin is moreover associated with the decrease in portal pressure. Terlipressin may therefore have potentially beneficial effects on the hyperdynamic circulation in cirrhosis in addition to its effects on portal pressure.

Adult↗
PubMed2000

Simplified scintigraphic methods for measuring gastrointestinal transit times.

To investigate whether simple transit measurements based on scintigraphy performed only 0, 2, 4 and 24 h after intake of a radiolabelled meal can be used to predict the mean transit time values for the stomach, the small intestine, and the colon, a study was conducted in 16 healthy volunteers. After ingestion of a meal containing 111indium-labelled water and 99mtechnetium-labelled omelette, imaging was performed at intervals of 30 min until all radioactivity was located in the colon and henceforth at intervals of 24 h until all radioactivity had cleared from the colon. Gastric, small intestinal and colonic mean transit times were calculated for both markers and compared with fractional gastric emptying at 2 h, fractional colonic filling at 4 h, and geometric centre of colonic content at 24 h, respectively. Highly significant correlations were found between gastric mean transit time and fractional gastric emptying at 2 h (111In: r=0.95, P<0.00001; 99mTc: r=0.96, P<0.00001), between small intestinal mean transit time and fractional colonic filling at 4 h (111In: r=-0.97, P<0.00001; 99mTc: r=-0.89, P<0. 00001), and between colonic mean transit time and geometric centre of colonic content at 24 h (111In: r=- 0.88, P<0.00001). We therefore conclude that reliable regional gastrointestinal transit times can be estimated from scintigraphic images taken 0, 2, 4 and 24 h after intake of radiolabelled markers.

Adult↗
PubMed2000

Gastrointestinal motor function in patients with portal hypertension.

BACKGROUND: Existing data on gastric emptying and small-intestinal transit rates in portal-hypertensive patients are scarce and contradictory, and so far, the motor function of the colon has not been assessed in these patients. In this study we evaluated the propulsive effect of all main segments of the gastrointestinal tract in patients with well-characterized portal hypertension. METHODS: Eight patients with a postsinusoidal hepatic pressure gradient of at least 13 mmHg and eight age- and sex-matched healthy controls participated in the study. Gastric emptying, small-intestinal transit, and colonic transit rates were evaluated in all subjects by means of a gamma camera technique. The technique was also used to measure the frequency of antral contractions. RESULTS: No difference was observed in gastric mean emptying time or small-intestinal mean transit time of liquid and solid markers between patients and controls. After 24 h, however, the geometric center of the liquid marker had a more caudal localization in the colon of the patient group than in the controls (P = 0.04); that is, the patients had a faster colonic transit. No difference was found in the frequency of antral contractions 45 min after the test meal between patients and controls. CONCLUSIONS: These data suggest that the colonic transit is often accelerated in patients with portal hypertension, whereas the motor function of the stomach and the small intestine is unaffected.

Adult↗
PubMed1999

Increased circulating leptin in alcoholic cirrhosis: relation to release and disposal.

Leptin is a cytokine peptide that decreases appetite and thereby food intake and increases energy expenditure. It is produced in fat cells, but recent animal experiments have shown expression of leptin in modified stellate hepatic cells. Because a change in circulating leptin in cirrhosis could be caused by an altered production rate, altered disposal rate, or both, the present study was undertaken to identify regions of leptin overflow into the blood stream and regions of leptin extraction. Patients with alcoholic cirrhosis (n = 16) and control patients without liver disease (n = 12) were studied during catheterization with elective blood sampling from different vascular beds. Blood samples for leptin determination (radioimmunoassay) were taken simultaneously from artery/hepatic vein, artery/renal vein, artery/iliac vein, and artery/cubital vein. Patients with cirrhosis had significantly increased circulating leptin (7.3 vs. control 2.6 ng/mL, P <.002) that correlated directly to ascitic-free body mass index (r = 0.71, P <.005). A significant renal extraction ratio of leptin was observed in control patients (0. 16) and in patients with cirrhosis (0.07), but the latter value was significantly lower than in the control patients (-44%, P <.05) and inversely correlated to serum creatinine (r = -0.60, P <.05). A significant, but equal, hepatosplanchnic extraction of leptin was observed in cirrhotic patients and control patients (0.08 vs. 0.07). In patients with cirrhosis a significant cubital venous-arterial difference in leptin was observed, but not in control patients. The iliac venous/arterial leptin ratio was significantly above 1.0 in both groups and of similar size (1.16 vs. 1.15), but a higher difference in concentration was found in the cirrhotic patients (+33%, P <.05). The spillover rates of leptin in cirrhotic patients may be even higher than estimated from the increased systemic veno-arterial gradients. In conclusion, the elevated circulating leptin in patients with cirrhosis is most likely caused by a combination of decreased renal extraction and increased release from subcutaneous abdominal, femoral, gluteal, retroperitoneal pelvic, and upper limb fat tissue areas. The hepatosplanchnic bed drained through hepatic veins could not be identified as a source of increased circulating leptin in cirrhosis, but a contribution by the portosystemic collateral flow cannot be excluded.

Adult↗
PubMed1999

A deconvolution technique for processing small intestinal transit data.

The deconvolution technique can be used to compute small intestinal impulse response curves from scintigraphic data. Previously suggested approaches, however, are sensitive to noise from the data. We investigated whether deconvolution based on a new simple iterative convolving technique can be recommended. Eight healthy volunteers ingested a meal that contained indium-111 diethylene triamine penta-acetic acid labelled water and technetium-99m stannous colloid labelled omelette. Imaging was performed at 30-min intervals until all radioactivity was located in the colon. A Fermi function=(1+e-alphabeta)/(1+e(t-alpha)beta) was chosen to characterize the small intestinal impulse response function. By changing only two parameters, alpha and beta, it is possible to obtain configurations from nearly a square function to nearly a monoexponential function. Small intestinal input function was obtained from the gastric emptying curve and convolved with the Fermi function. The sum of least squares was used to find alpha and beta yielding the best fit of the convolved curve to the observed small intestinal time-activity curve. Finally, a small intestinal mean transit time was calculated from the Fermi function referred to. In all cases, we found an excellent fit of the convolved curve to the observed small intestinal time-activity curve, that is the Fermi function reflected the small intestinal impulse response curve. Small intestinal mean transit time of liquid marker (median 2.02 h) was significantly shorter than that of solid marker (median 2.99 h; P<0.02). The iterative convolving technique seems to be an attractive alternative to ordinary approaches for the processing of small intestinal transit data.

Adult↗
PubMed1998

[Scientific activities in departments of clinical physiology/nuclear medicine in Denmark during the period 1989-1994. A bibliometric analysis of the "impact" and citation frequency].

This study reports a bibliometric analysis of 860 scientific publications of which 763 are papers in scientific journals emanating from departments of clinical physiology and nuclear medicine in Denmark in the years 1989-1994. The number of publications decreased significantly over time. The 763 papers were published in 239 different scientific journals, 80% in journals with an official "impact factor". The average impact per paper remained almost constant over time and was significantly above the national average. A close relationship was found between the number of papers from a department and its cumulated impact. In an analysis of 217 papers a direct relation was found between the journal impact factor and the citation factor. A linear relation was found between cumulated citations and time, and the number of citations per year reached a maximum 3-7 years after publication, whereas the general maximum for all medical specialties is 2-3 years. It is concluded that the total number of scientific papers from Danish departments of clinical physiology & nuclear medicine fell in the years 1989-1991, but the impact per paper was almost constant and above the national average. There seems to be a good agreement between journal impact factor and overall citation frequency in papers from clinical physiology & nuclear medicine.

Bibliometrics↗
PubMed1997

Effect of octreotide on systemic, central, and splanchnic haemodynamics in cirrhosis.

BACKGROUND/AIMS: Cirrhosis with portal hypertension is associated with changes in the splanchnic and systemic haemodynamics, and subsequent complications, such as bleeding from oesophageal varices, have led to the introduction of long-acting somatostatin analogues in the treatment of portal hypertension. However, reports on the splanchnic and systemic effects of octreotide are contradictory and therefore the aim of the present study was to assess the effects of continuous infusion of octreotide on central and systemic haemodynamics, portal pressures, and hepatic blood flow. METHODS: Thirteen patients with cirrhosis underwent liver vein catheterisation. Portal and arterial blood pressures were determined at baseline and 10, 30, and 50 min after a bolus injection of octreotide 100 micrograms, followed by continuous infusion of octreotide 100 micrograms/ h for 1 h. Hepatic blood flow, cardiac output, central and arterial blood volume, and central circulation time were determined at baseline and 50 min after the start of the octreotide infusion. RESULTS: The mean arterial blood pressure increased during the first 10 min (p < 0.0005), but returned to baseline after 50 min. The central and arterial blood volume (-16%, p < 0.005) and the central circulation time (-8%, p < 0.05) were significantly decreased after 50 min, whereas the cardiac output did not change significantly. The hepatic venous pressure gradient and the hepatic blood flow did not change significantly at any time after infusion of octreotide. CONCLUSIONS: Octreotide does not affect the portal pressure or hepatic blood flow, whereas it may further contract the central blood volume and thereby exert a potentially harmful effect on central hypovolaemia in patients with cirrhosis. However, these early effects do not exclude the possibility that administration of longacting somatostatin analogues over a longer period may have a beneficial effect.

Adult↗
PubMed1996

Scientific publications from departments of clinical physiology and nuclear medicine in Denmark. A bibliometric analysis of "impact' in the years 1989-1994.

This study reports a bibliometric analysis of scientific publications emanating from departments of clinical physiology and nuclear medicine, Denmark, during the years 1989-1994. The total number of publications during this period was 860 (763 scientific journal papers, 71 book/book chapters and 26 theses). Whereas the number of publications per year (188-113) decreased significantly with time (r = -0.94, P < 0.02), the number of authors (mean 4.1) was almost constant over time. University/ university-related departments accounted for 96% of the papers. Only 8% of the papers resulted from a collaboration between two or more departments of clinical physiology and nuclear medicine, but the collaboration with other medical specialities and institutions was much greater (85%). The 763 papers were published in 239 different scientific journals, 80% in journals with an official 'impact factor', a bibliometric measure of quality (the average number of times a paper is cited in a journal in the publishing year and the subsequent year). Twenty per cent (20%) and 8.4% were printed in journals with an impact factor, respectively, of above 2.1 (the 500 journals most cited) and 3.7 (the 200 most cited), which is significantly above the national average 16.6% and 6.0%, P < 0.001). The "cumulated impact' (i.e. the impact of all papers) showed a borderline significant decrease over time (r = -0.77, P = 0.1), whereas the average impact per paper (1.53) remained almost constant and was significantly above the national average (1.10, P < 0.001). A close relationship was found between the number of papers from a department and its cumulated impact (r = -0.97, P < 0.001). It is concluded that the total number of scientific papers from Danish departments of clinical physiology and nuclear medicine fell in the period, whereas the volume of quality, as assessed on the cumulated impact, only fell with borderline significance, and the impact per paper was almost constant from 1989 to 1994, and was above the national average.

Bibliometrics↗
PubMed1996

No effect of oxygen therapy on myocardial ischaemia during gastroscopy.

BACKGROUND: Myocardial ischaemia (defined as an ST-segment depression on ECG) may occur during upper gastrointestinal endoscopy, but the mechanism is still unknown. The aim of our study was to evaluate the effect of oxygen therapy and tachycardia on the occurrence of ST-segment depression during routine diagnostic esophagogastroduodenoscopy. METHODS: Eighty-nine consecutive patients were randomized to receive either oxygen (21/min by nasal prongs) or nothing during endoscopy, in which arterial oxygen saturation was measured by continuous pulse oximetry, and ECG was measured continuously with a Holter tape recorder. RESULTS: A total of 28 patients (12 receiving oxygen) developed ST-segment depression ( > 0.1 mV) during endoscopy. In 22 patients (12 receiving oxygen) ST depression was related to tachycardia, and in 5 of these (none receiving oxygen) simultaneous episodic hypoxaemia was present during the event. Thus, in every case of ST depression related to episodic hypoxaemia there was simultaneous tachycardia. In six patients developing ST depression during endoscopy we did not find preendoscopy levels, and 63 patients (29 receiving oxygen) developed tachycardia during the procedure (rate > 100 min-1_. CONCLUSIONS: Oxygen therapy had no significant effect on the occurrence of ST-segment depression during upper gastrointestinal endoscopy. The results suggest that tachycardia is more important than hypoxaemia in the pathogenesis of ST depression during gastroscopy.

Adult↗
PubMed1995

[Portal hypertensive gastropathy].

Portal hypertensive gastropathy (PHG) as defined by congestive changes in the gastric mucosa owing to increased portal pressure, was first described about ten years ago. Whereas definition and grading of severity are still under debate, there is general agreement that PHG is a new clinical entity. PHG is present in 50-80% of patients with liver cirrhosis. PHG is a major cause of upper gastrointestinal bleeding in patients with portal hypertension (25-90% depending on severity). Presence of portal hypertension is a prerequisite for the development of PHG, and reduction of portal pressure and splanchnic blood flow with beta-adrenergic blockers has shown promising results, but an established medical treatment of PHG does not exist. Trials with new vasoactive drugs are awaited.

Chronic Disease↗
PubMed1990

Sexual dysfunction in male and female patients with epilepsy: a study of 86 outpatients.

Sexual dysfunction is a well-known complication of chronic somatic illness. Eighty-six consecutive epileptic outpatients, 38 men and 48 women, without accompanying disorders, were studied. The frequency and symptoms of sexual dysfunction were compared with results from previous studies using identical sexological methodology. The previous studies were of diabetic patients and healthy controls. Eight percent of the epileptic men reported a sexual dysfunction compared to 44% of the diabetics and 13% of the controls. Epileptic women, diabetic women, and controls showed no significant differences in sexual dysfunction (29%, 28%, and 25%, respectively). In both sexes, the sexual function measured by frequencies of coitus and masturbation was normal. Most patients had good control of epileptic attacks on a treatment of monotherapy. Hormonal status was generally within normal limits in both men and women; only a few minor differences were found and they showed no correlation with sexual dysfunction. Psychologically and socially the patients did not differ appreciably from normals, and they exhibited a high degree of disease acceptance. This study, using a biopsychosocial approach in understanding sexual dysfunctions, is in contrast with previous, mainly uncontrolled, studies of epileptic patients that reported high frequencies of "hyposexuality" in males. We conclude that epilepsy does not necessarily increase the risk of sexual dysfunction in male or female.

Adult↗