Elevated ectodomain of type 23 collagen is a novel biomarker of the intestinal epithelium to monitor disease activity in ulcerative colitis and Crohn's disease

BACKGROUND

Impaired intestinal epithelial barrier is highly affected in inflammatory bowel disease. Transmembrane collagens connecting the epithelial cells to the extracellular matrix have an important role in epithelial cell homeostasis. Thus, we sought to determine whether the transmembrane type 23 collagen could serve as a surrogate marker for disease activity in patients with Crohn's disease and ulcerative colitis.

METHODS

We developed an enzyme-linked immunosorbent assay to detect the ectodomain of type 23 collagen (PRO-C23) in serum, followed by evaluation of its levels in both acute and chronic dextran sulphate sodium colitis models in rats and human inflammatory bowel disease cohorts. Serum from 44 Crohn's disease and 29 ulcerative colitis patients with active and inactive disease was included.

RESULTS

In the acute and chronic dextran sulphate sodium-induced rat colitis model, the PRO-C23 serum levels were significantly increased after colitis and returned to normal levels after disease remission. Serum levels of PRO-C23 were elevated in Crohn's disease (p < 0.05) and ulcerative colitis (p < 0.001) patients with active disease compared to healthy donors. PRO-C23 differentiated healthy donors from ulcerative colitis (area under the curve [AUC]: 0.81, p = 0.0009) and Crohn's disease (AUC: 0.70, p = 0.0124). PRO-C23 differentiated ulcerative colitis patients with active disease from those in remission (AUC: 0.75, p = 0.0219) and Crohn's disease patients with active disease from those in remission (AUC: 0.68, p = 0.05).

CONCLUSION

PRO-C23 was elevated in rats with active colitis, and inflammatory bowel disease patients with active disease. Therefore, PRO-C23 may be used as a surrogate marker for monitoring disease activity in ulcerative colitis and Crohn's disease.

Correlates of different facets and components of beta diversity in stream organisms

Recently, community ecology has emphasized the multi-facetted aspects of biological diversity by linking species traits and the environment. Here, we explored environmental correlates of taxonomically-based and traits-based compositional distances using a comprehensive data set of diatom and macroinvertebrate communities. We also explored the responses of different beta diversity components (i.e., overall beta diversity, turnover, and nestedness) of beta diversity facets (i.e., taxonomically and traits-based beta diversity) to environmental distances. Partial Mantel tests were used to test the relationships between beta diversity and environmental distance (while controlling for spatial distances). Taxonomically-based beta diversity varied much more than traits-based beta diversity, indicating strong functional convergence. We found that taxonomically-based beta diversity was largely driven by the turnover component. However, the nestedness component contributed more to overall traits-based beta diversity than the turnover component. Taxonomically-based beta diversity was significantly correlated with environmental distances for both diatoms and macroinvertebrates. Thus, we found support for the role of environmental filtering as a driver of community dissimilarities of rather different biological groups. However, the strength of these relationships between beta diversity and environmental distances varied depending on the biological group, facet, component, and the way which the environmental variables were selected to calculate the explanatory (distance) matrix. Our results indicated that both taxonomically and traits-based approaches are still needed to better understand patterns and mechanisms affecting the organization of biological communities in streams. This is because different facets of biological communities may be driven by different mechanisms.

The intestinal tissue homeostasis - the role of extracellular matrix remodeling in inflammatory bowel disease

Introduction: Extracellular matrix (ECM) remodeling of the intestinal tissue is important in inflammatory bowel disease (IBD) due to the extensive mucosal remodeling. There are still gaps in our knowledge as to how ECM remodeling is related to intestinal epithelium homeostasis and healing of the intestinal mucosa.Areas covered: The aim of this review is to highlight the importance of the ECM in relation to the pathogenesis of IBD, while addressing basement membrane and interstitial matrix remodeling, and the processes of wound healing of the intestinal tissue in IBD.Expert opinion: In IBD, basement membrane remodeling may reflect the integrity of the intestinal epithelial-cell homeostasis. The interstitial matrix remodeling is associated with deep inflammation such as the transmural inflammation as seen in fistulas and intestinal fibrosis leading to fibrostenotic strictures, in patients with CD. The interplay between wound healing processes and ECM remodeling also affects the tissue homeostasis in IBD. The interstitial matrix, produced by fibroblasts, holds a very different biology as compared to the epithelial basement membrane in IBD. In combination with integration of wound healing, quantifying the interplay between damage and repair to these sub compartments may provide essential information in IBD patient profiling, mucosal healing and disease management.

Global patterns in the metacommunity structuring of lake macrophytes: regional variations and driving factors

We studied community-environment relationships of lake macrophytes at two metacommunity scales using data from 16 regions across the world. More specifically, we examined (a) whether the lake macrophyte communities respond similar to key local environmental factors, major climate variables and lake spatial locations in each of the regions (i.e., within-region approach) and (b) how well can explained variability in the community-environment relationships across multiple lake macrophyte metacommunities be accounted for by elevation range, spatial extent, latitude, longitude, and age of the oldest lake within each metacommunity (i.e., across-region approach). In the within-region approach, we employed partial redundancy analyses together with variation partitioning to investigate the relative importance of local variables, climate variables, and spatial location on lake macrophytes among the study regions. In the across-region approach, we used adjusted R2 values of the variation partitioning to model the community-environment relationships across multiple metacommunities using linear regression and commonality analysis. We found that niche filtering related to local lake-level environmental conditions was the dominant force structuring macrophytes within metacommunities. However, our results also revealed that elevation range associated with climate (increasing temperature amplitude affecting macrophytes) and spatial location (likely due to dispersal limitation) was important for macrophytes based on the findings of the across-metacommunities analysis. These findings suggest that different determinants influence macrophyte metacommunities within different regions, thus showing context dependency. Moreover, our study emphasized that the use of a single metacommunity scale gives incomplete information on the environmental features explaining variation in macrophyte communities.

Is distribution of cold stenotherms constrained by temperature? The case of the Arctic fairy shrimp (Branchinecta paludosa O.F. Müller 1788)

Small water bodies in cold climate respond fast to global warming, and species adapted to such habitats may be valuable indicators for climate change. We investigated the geographical and physiological temperature limits of the Arctic fairy shrimp (Branchinecta paludosa), which is common in cold water arctic ponds, but at present retracts its range in alpine areas along its southern outreach of Norway. Seasonal logging of water temperatures along an altitudinal transect revealed an upper temperature limit of 12.7°C for its presence, which closely matched a calculated upper temperature limit of 12.9°C throughout its entire Norwegian range. Field data hence point to cold stenotherm features, which would be consistent with its Arctic, circumpolar distribution. Lab experiments, on the other hand, revealed a linear increase in respiration over 10-20°C. When fed ad libitum somatic growth increased with temperature, as well, without negative physiological impacts of higher temperatures. The absence of Branchinecta paludosa in ponds warmer than 13°C could still be due to a mismatch between temperature dependent metabolism and limited energy supply in these ultraoligotrophic water bodies. We discuss the concept of cold stenothermy in this context, and the impacts of regional warming on the future distribution of the Arctic fairy shrimp.

The effect of carnitine supplemented total parenteral nutrition on lipid, energy and nitrogen metabolism in severely ill patients

To analyse the effects of L-carnitine supplemented TPN on lipid, energy and nitrogen metabolism, 16 severely injured patients were studied during the first 8 days after trauma. An L-carnitine solution (3g = 18.6mmol) was added to the fat emulsion and infused over 16h in a blind randomised fashion to half of the patients. Plasma triglyceride, free fatty acid and 3-OH-butyrate concentrations increased during the fat infusion, and fell to pre-infusion concentrations within 24h. There were no differences in plasma levels before, during or after infusion between the groups. ATP and phosphocreatine in muscle tissue were not influenced by carnitine supplementation. Glycogen, however, remained unchanged in the carnitine group and fell in the non-carnitine group. A cumulative N-balance measured from day 2 to day 8 was equally negative in both groups. Plasma carnitine levels were significantly higher in the supplemented group from day 3. The mean daily urinary carnitine excretion was increased 15-fold in the supplemented group. Muscle carnitine, however, remained unchanged in both groups and did not differ between them. The present results do not demonstrate any beneficial effects of parenterally administered L-carnitine on lipid, energy or nitrogen metabolism except for maintaining normal muscle glycogen levels in critically ill patients receiving TPN during the early phase after trauma.

Working conditions, psychosocial resources and work stress in nurses and physicians in chief managers' positions

The study investigated whether psychosocial work conditions, professional network, job support, social network and support, sick leave and salary were associated with work stress in nurses in chief manager' positions above ward level and physicians in clinical director positions. A sample consisting of 205 nurses and 274 physicians in chief managers' positions at higher structural level answered a questionnaire. Odds ratios were used for estimating the bivariate association between work stress and psychosocial resources. The result showed that both nurse managers (OR 6.8; 95% CI: 3.5-13.5) and clinical directors (OR 6.7; 95% CI: 3.6-12.5) exposed to high job demands had a significantly higher probability of high level of work stress. The results also indicated that the available psychosocial resources taken together inside and outside work did not balance the experienced work stress in nurse managers and the clinical directors who were exposed to high work demands. No relation was found between work stress and sick leave and salary.

Nurse managers' professional networks, psychosocial resources and self-rated health

BACKGROUND

Nurse managers act under constant pressure to develop strategies in response to professional challenges within a changing and restructured health care system. When such environmental stress is present, they need access to sufficient psychosocial recourse.

AIM

The study aimed to investigate whether nurse managers' professional networks, psychosocial work conditions, job support, social network and support were associated with self-rated health, sick-leave and salary.

METHODS

From a total of 268 Swedish nurse managers, active in management positions, 205 (77%) agreed to participate in the study by answering a self-report questionnaire. Cronbach's alpha was used to calculate internal consistency. Odds ratios were used to estimate the bivariate association between self-rated health and psychosocial resources.

RESULTS

Nurse managers exposed to high job demands had significantly increased odds for low self-rated health. It was also found that low level of support from professional network, job support, social network and social support outside work displayed increased odds for low self-rated health, independently of age, gender and education. There were additive (but no synergistic) effects found for job demand in combination with professional networks, job support and emotional support and in relation to self-rated health.

CONCLUSION

The study showed that nurse managers exposed to high job demands had elevated odds for low self-rated health, regardless of level of psychosocial resources within or outside work. Two-thirds of the nurse managers who were affiliated to professional networks did not consider this a supporting factor in their management work. Those with low job support had increased odds for sick-leave compared with those with high support. No significant associations were found between psychosocial characteristics and salary.

Nurse managers' management direction and role over time

This study illuminates how 27 nurse managers experienced management direction and roles over a time period of three years. Fourteen of the nurse managers worked full-time in management positions during the time, while 13 during the same time completed a professional development course in advanced nursing at master-degree level. Two main directions were identified. One focused on management from the perspective of power and power transference, and the other focused on management from the perspective of theoretical knowledge related to nursing development.

Influence of nursing management education on management direction and role

The authors discuss how 13 nurse managers in Sweden experienced management direction and the management role before and 1 year after a professional development course in advanced nursing at the masters-degree level. The nurse managers related theoretical knowledge to an increased awareness of further possibilities inherent in managerial positions. They stressed the importance of networking for future support and growth.

Management from four different perspectives

AIM

This study intended to illuminate nursing management in a developing organization from the perspectives of nurse managers, chief physicians, hospital directors and politicians.

BACKGROUND

Increased responsibility in a changing health care system makes it important that nurses occupy advantageous positions so that they may safeguard and facilitate the development of their core area.

METHODS

Open-ended taped interviews were conducted with 15 nurse managers, 11 chief physicians, three hospital directors and three politicians from three Swedish cities.

FINDINGS

The main theme found was power and three dependent themes were identified as; power within activities, being in power and freedom to act.

CONCLUSION

The four professional groups related their opinion of nursing management to the needs and interests of their own group. Acceptance or nonacceptance between the groups was discussed in terms of the concept of knowledge, which was interpreted as being a more acceptable topic for discussion than the phenomenon of power.

Inhibitory effect of gastrin peptides on triacylglycerol secretion in Hep G2 cells

OBJECTIVES

To determine whether human liver cells respond to gastrin peptides by reducing their secretion of triacylglycerols, as recently observed in rat hepatocytes.

DESIGN

Cells of the human hepatoblastoma cell line Hep G2 were incubated with pentagastrin and heptadeca gastrin, followed by lipid analysis of media and cells.

METHODS

Cultivation of cells; analyses of triacylglycerols, cholesterol and protein; statistical analysis.

RESULTS

As the secretion of triacylglycerols in Hep G2 cells incubated with basal medium (Eagle's minimum essential medium with non-essential amino acids, penicillin, streptomycin and glutamine) is only about 20% of the triacylglycerol secretion reported for human liver cells, the possibility of detecting statistically significant effects of gastrin peptides on lipid secretion is reduced compared to the situation in normal hepatocytes. However, by a combined addition of 0.1 mmol/l albumin-bound oleate, 10 mmol/l sodium butyrate and 0.1 mg/ml dextran sulphate to the basal medium, the triacylglycerol secretion in Hep G2 cells was found to be more than twice as high as in cells incubated with basal medium alone. With this supplemented medium a biphasic concentration-dependent statistically significant inhibitory effect of both pentagastrin and heptadeca gastrin on triacylglycerol secretion in Hep G2 cells was demonstrated.

CONCLUSION

These results indicate that gastrin peptides may play a role in the regulation of lipoprotein secretion in human liver cells.

Fluid absorption during transurethral bladder surgery

We report 2 patients who absorbed large amounts of irrigating fluid during transurethral resection of bladder tumours (TURB). Ethanol indication facilitated diagnosis of this complication and showed that absorption had occurred by the extravascular route. Symptoms occurred in one case but they resolved when hypertonic saline and furosemide were given.

Inhibitory effect of gastrin and cholecystokinin fragments on the secretion of triacylglycerol in rat hepatocytes

In this investigation we studied the influence of two gastrin fragments, pentagastrin and nonsulfated heptadecagastrin, and two cholecystokinin fragments, sulfated and desulfated cholecystokinin 26-33, on intracellular and secreted triacylglycerol in isolated hepatocyte cultures. Both gastrin fragments inhibited triacylglycerol release in a biphasic manner, exhibiting maximal effect at 0.1 nmol/L (nonsulfated heptadecagastrin) and 0.3 nmol/L (pentagastrin). At these concentrations triacylglycerol secretion was 42% (nonsulfated heptadecagastrin, p < 0.001) and 62% (pentagastrin, p < 0.001) lower than in cells untreated with gastrin. Sulfated cholecystokinin 26-33 caused a 35% decrease in triacylglycerol secretion at 0.1 nmol/L (p < 0.01), and desulfated cholecystokinin 26-33 caused a 53% decrease at 0.2 nmol/L (p < 0.001). In all experiments, the hormone-induced decrease in triacylglycerol secretion was accompanied by an increase in intracellular triacylglycerol content. The cholecystokinin-A receptor antagonist L-364, 718 did not affect the decrease in triacylglycerol secretion induced by 0.3 nmol/L pentagastrin, whereas the cholecystokinin-B receptor antagonist L-365, 260 inhibited the pentagastrin effect at concentrations above 50 nmol/L. These results suggest that gastrin, cholecystokinin or some other gastrinlike hormone (or all three) may play a previously unrecognized regulatory role with respect to hepatic very low density lipoprotein secretion.

Comparison of dietary casein and soybean protein effects on plasma lipid and gastrin levels, hepatic delta 6-desaturase activity and coronary arteriosclerosis in male Sprague-Dawley rats. A 9-month study

An increased concentration of gastrin was observed in plasma of male Sprague-Dawley strain rats fed on soybean protein diet for a 9-month period, compared with rats fed on casein diet. Both diets contained 0.5% (w/w) cholesterol. Protein-dependent differences were also observed in the fatty acid pattern of hepatic phospholipids, hepatic delta 6-desaturase activity, and plasma cholesterol. No signs of arteriosclerosis were observed in the aortas. Sixty percent of the hearts showed various degrees of lipid staining in coronary arterial branches of different sizes. Despite a large difference in plasma cholesterol level, there was no quantitative or qualitative difference between groups in the occurrence of coronary lipid staining.

Critically ill patients and fat emulsions

In critically ill patients, lipid tolerance may be impaired. In ICU, patients are usually given TPN including fat emulsions. If sedation with propofol is given simultaneously the fat load increases and may exceed the maximal clearing capacity of exogenous fat emulsion unless the administration of the parenteral fat is adjusted to take account of the lipid contained in propofol. An accumulation of fat may result in the so-called 'fat overload syndrome'. Close monitoring of serum triglyceride concentration is therefore recommended to avoid fat overload.

Hepatotoxicity due to repeated intake of low doses of paracetamol

The cases of two patients with fulminant hepatic failure after intake of therapeutic doses (4-8 g) of paracetamol, and who were admitted to hospital for assessment for liver transplantation, are described. In both patients starvation, due to abdominal pain, nausea and vomiting or diarrhoea, was probably contributing to the toxic effect of the drug. One of the patients also had an excessive alcohol intake. Paracetamol should not be prescribed for patients with alcoholism or with low food intake.

The effects of dietary protein on the fatty acid composition and delta 6 desaturase activity of rat hepatic microsomes

Recently, significant differences between rats fed a casein diet and rats fed a soybean protein diet have been observed in hepatic phospholipid fatty acid patterns (Sjöblom, L., and Eklund, A., Biochim. Biophys. Acta 1004, 187-192, 1990). The influence of these two diets on the delta 6 desaturase activity was investigated in the present study because the hepatic desaturase system is a source of unsaturated fatty acids. The rats fed a casein diet showed higher desaturase activity than those fed soybean protein when using either linoleic acid (P less than 0.005) or oleic acid (P less than 0.05) as substrates. The phosphatidylcholine fraction of hepatic microsomes showed increases in oleic acid (P less than 0.005) and 20:3 omega 9 (P less than 0.001) levels as well as decreases in stearic acid (P less than 0.001), linoleic acid (P less than 0.005) and arachidonic acid (P less than 0.005) levels in rats which were fed casein rather than soybean protein. Similar differences between the two groups were also observed in the phosphatidylethanolamine and phosphatidylinositol fractions. These data indicate that the qualitative properties of the dietary protein source may influence the fatty acid pattern of rat hepatic microsomes by interfering with delta 6 desaturase activity.

Accuracy of plasma turbidity measurement for determining fat intolerance during total parenteral nutrition

The accuracy of plasma turbidity measurements in predicting ability to metabolise intravenous fat emulsions during total parenteral nutrition was studied in 35 adult surgical patients. Plasma turbidity, expressed as a light scattering index (LSI), was determined by nephelometry and compared with measured triglyceride (TG) concentrations. A poor coefficient of correlation was found between LSI and TG (r = 0.52). The sensitivity and specificity of LSI in predicting TG concentration were 19% and 96% respectively. This indicates that the measurement of LSI is more useful in ruling out hypertriglyceridaemia than in detecting it. Consequently, clinical tolerance of intravenous fat emulsion cannot be monitored by measuring plasma turbidity. In order to avoid metabolic complications which may occasionally occur during intravenous nutritional therapy including fat emulsion, determination of plasma TG levels at timed intervals are recommended.

Pregnanolone emulsion. A preliminary pharmacokinetic and pharmacodynamic study of a new intravenous anaesthetic agent

Pregnanolone emulsion, a new steroid anaesthetic agent, was administered intravenously as bolus doses to six young healthy male volunteers in a preliminary pharmacokinetic and pharmacodynamic study. The plasma concentration-time curves fitted a two-compartment model. The elimination half-life was between 0.9 and 1.4 hours, volume of central compartment between 0.95 and 2.10 litres/kg, volume of distribution between 3.75 and 5.58 litres/kg and total body clearance between 1.80 and 3.07 (litres/hour)/kg. The excretion in urine of unchanged pregnanolone was less than 0.1%. The pharmacodynamic properties were found to be similar to those of Althesin, with immediate induction of anaesthesia of short duration. The anaesthetic affected haemodynamics only slightly; minor depression of ventilation, with an increase in PaCO2, occurred in several of the subjects. Excitation of short duration occurred in one subject during induction of sleep and slight involuntary muscle movements in another subject during sleep. It is impossible to draw any clear conclusions of the clinical efficacy and tolerance from this limited normal subject trial, but pregnanolone emulsion seems worthy of further clinical trial.

Time course for the changes of serum lipoproteins and apolipoprotein T concentrations after major surgical trauma in man

Trauma induces changes in the serum lipoprotein pattern in man. A characteristic apolipoprotein, named apolipoprotein T existing in its isoforms T-I to T-IV, in the high density lipoprotein (HDL) fraction of serum, also appears in response to trauma. In this report eight patients operated on for abdominal aortic aneurysms were studied concerning the time dependency in changes of serum lipoproteins and the appearance of apolipoprotein T. Blood samples for lipoprotein analysis were taken preoperatively, postoperatively on days 1, 2, 4, 6 and thereafter twice a week until discharge from the hospital. The serum lipoprotein concentrations were compared with those from a group of healthy men. The most striking abnormalities were found in serum VLDL where both concentrations of triglycerides and cholesterol decreased during the first 2 days by more than 50%, compared to the initial level, and remained low for about 1 week. Also the concentration of LDL cholesterol in serum decreased about 40% from the preoperative value during the first days. Serum HDL cholesterol either increased during the first 2 days in those patients with a low preoperative concentration or stayed on a subnormal level during the first 4 days. After day 4 the serum HDL cholesterol decreased and reached the minimum level on days 10 to 13. Already on day 1 after trauma apolipoprotein T had reached a high level in order to stay high for several weeks. The apolipoprotein T isoforms had different appearance with time and varied independently of serum cholesterol in HDL.

Intralipid disappearance in critically ill patients

Intralipid elimination patterns were compared in 25 healthy controls, 12 patients recovering from uncomplicated cholecystectomy, and 25 critically ill patients. The intravenous fat tolerance test revealed a similar fractional removal rate (k2) in healthy controls and critically ill patients, but k2 was increased in cholecystectomy patients. The concentration of cross-reactive protein (CRP) correlated positively to the concentration of total triglyceride and low-density lipoprotein-triglyceride, and negatively to low-density lipoprotein-cholesterol and high-density lipoprotein-cholesterol. The extrapolated zero-time concentration of Intralipid in the critically ill patients was only one-third of the value in healthy controls. After this initial loss, however, Intralipid was removed from the circulation after first-order kinetics. These low concentrations of Intralipid were not correlated with concentrations of CRP. Possible explanations for this phenomenon include a change in the configuration of the lipid particles, the so-called creaming phenomenon, and/or immediate and substantial uptake of the emulsion by certain organs.

Agglutinate formation in serum samples mixed with intravenous fat emulsions

The degree of fat agglutination (the so-called "creaming phenomenon") was measured in sera from 51 critically ill patients, 200 ambulatory patients and 24 healthy volunteers. A 400-microliter serum sample was mixed with 10 microliter of a fat emulsion (Intralipid), incubated at 37 degrees C, and examined after 2, 6, and 24 h. Almost all samples from critically ill patients exhibited creaming, as did 31% of the samples from ambulatory patients. Serum samples from healthy volunteers were incubated with purified C-reactive protein (CRP). At a CRP concentration of 40 mg/L, creaming was always observed. Creaming also occurred at normal serum levels of CRP, but at increased concentrations of other serum proteins. Finally, the creaming test was performed with 12 different fat emulsions, mixed with sera from critically ill and healthy subjects. Healthy sera produced no creaming and sera from critically ill patients invariably showed creaming with every emulsion.

Phosphate supplementation in parenteral nutrition

Pronounced serum phosphate deficiency has been shown to be deleterious when starting parenteral nutrition in severely malnourished patients. The consequences of phosphate deficiency and the need for phosphate supplementation in critically ill patients are not well known. Thirty ICU patients randomized into two groups were studied. The patients received complete parenteral nutrition with and without addition of extra phosphate. The low phosphate group got 7.5 mmol phosphate (from the phospholipids in the fat emulsion) and the high phosphate group got 60-80 mmol phosphate/day. There were no significant differences in serum phosphate or calcium levels between the groups. In the high phosphate group the phosphate balance was positive and calcium balance zero while in the low phosphate group both phosphate and calcium balances were negative. The phosphate content in a standard nutrition programme is not sufficient to create a positive phosphate balance. With the addition of 80 mmol phosphate/day a positive balance was achieved. It is hard to establish guidelines for the administration of phosphate in ICU patients. 20-40 mmol may normally be satisfactory but we have shown that ICU patients may need and can tolerate up to 80 mmol/day.

Plasma catecholamine and free fatty acid levels during infusion of lipid emulsion in critically ill patients

The fractional elimination rate of exogenous fat, and fat-mobilizing lipolysis in relation to plasma catecholamine (CA) levels were studied in seven ventilator-treated ICU patients. Blood levels of CA, triglycerides, cholesterol and free fatty acids (FFA) were also analyzed before and during constant infusion of a soybean oil emulsion (Intralipid). Triglyceride concentrations rose significantly during the infusion. FFA levels also increased significantly within 30 min after the infusion was begun, reflecting fatty acids derived from Intralipid triglycerides. Plasma norepinephrine levels showed large interindividual variations and were inversely related to FFA concentrations. No correlation was found between plasma CA levels and the fractional removal rate of fat. These data suggest a deficiency of substrate in these critically ill patients.

Interrelations between lipoprotein and the elimination of exogenous triglycerides from the circulation in intensive care patients

The interrelations between the fractional turnover rate (k2) of exogenous triglycerides from the circulation and the serum lipoproteins have been studied in 34 intensive care patients who were classified into two groups depending on the severity of the clinical condition. Group I included 13 patients in relatively good clinical condition after elective surgery and Group II consisted of 21 critically ill patients. The k2 values were increased in Group I while Group II patients had K2 values similar to healthy male controls. Low concentrations of total serum TG, VLDL-TG and total serum cholesterol were found in Group I and LDL-TG was raised more than threefold and HDL cholesterol decreased by over 50 percent in Group II. In both groups the cholesterol/TG ratio in VLDL was higher than that of the controls. The negative correlations between K2, total serum TG and VLDL-TG in controls were also found in Group I. In contrast to the control group a positive correlation between K2 and the cholesterol/TG ratio in VLDL was found in Group I, whereas the only correlations found in Group II were between K2 and the concentration of both total serum cholesterol and LDL cholesterol. There was no correlation with HDL lipids in any of the groups. Qualitative changes in the lipoprotein composition and altered characteristics in the tissues which remove Intralipid particles from the circulation may be responsible for many of the changes observed.

Rate of elimination of the intralipid fat emulsion from the circulation in ICU patients

The rate of removal of Intralipid was studied in 2 groups of intensive care patients by analysis of the fractional removal rate after a single iv dose and by analysis of the removal rate during a constant infusion of Intralipid which immediately followed. The patients in group I were moderately ill after uncomplicated surgery whereas group 2 patients were critically ill and had a mortality of 44%. The fractional removal rate was 2-fold greater in group 1 than group 2 and controls; the 2 latter groups had similar rates of removal. During the constant infusion of Intralipid, 0.42 g/min for 3 h, group 1 patients were found to have a first order removal rate with a constant plasma concentration of Intralipid. The rate constants were not different during the entire infusion from those obtained by the single injection. In all of the group 2 patients, a zero order removal rate was present as the concentration of Intralipid particles increased linearly with time. Group 2 patients had cleared all Intralipid within 6 h after the end of the infusion. Some patients were treated with heparin and/or insulin for clinical reasons. The removal rates were not influenced in either group by these drugs. Thus, moderately traumatized patients were found to clear plasma from Intralipid at recommended infusion rates. However, in critically ill patients, the infusion rate of Intralipid may have to be adjusted below the maximal elimination capacity to avoid Intralipid accumulation in plasma.

Pronounced dyslipoproteinemia in intensive care patients

Concentrations of triglycerides (TG) and cholesterol in serum and in lipoproteins were determined in two groups of intensive care patients. Group I included 17 moderately ill, postelective surgery patients, and group II, 23 critically ill patients. All were studied in an intensive care situation. The lipoprotein lipid concentrations were compared with those from a group of healthy men and women. In group I, both TG and cholesterol concentrations in serum were decreased, whereas in group II, only cholesterol concentration was lowered and the TG concentration was close to control values. In the lipoproteins, marked abnormalities were found. The most striking was an increase in low density lipoprotein (LDL)-TG and a decrease in high density lipoprotein (HDL)-cholesterol concentrations. In group II, 5/18 males had a LDL-TG concentration above any control value and 21/23 had a HDL-cholesterol concentration below any value in the control group. In addition, the alpha-lipoprotein (HDL) band on electrophoresis was often grossly abnormal with a broad or double-peaked band. There was a highly significant negative correlation between LDL-TG and HDL-cholesterol concentrations. Patients who received conventional treatment with insulin or heparin had similar lipid concentrations as those not given these drugs. The time effect on lipoprotein changes was analyzed in 11 patients, from whom samples were drawn repeatedly during the intensive care period. A tendency was found for LDL-TG to increase and HDL-cholesterol to decrease with time. The mechanisms causing the lipoprotein changes are not presently known; however, possible explanations include liver function impairment, gastrointestinal tract paralysis, physical inactivity, the catabolic state as such, and combinations.

Hemodynamic effects of hyperosmolal glucose infusion in the critically ill patient

A 30% glucose solution was infused for 4 h at a rate of 1.53 ml . kg-1, corresponding to 10 g . kg-1 . 24 h-1 in 8 critically ill patients requiring parenteral nutrition. The osmotic load resulted in an expanded blood volume due to hemodilution. Stroke volume (SV) increased, while peripheral vascular resistance (PVR) and pulmonary capillary wedge pressure (WP) decreased. Otherwise, no major effects on the circulation were observed. Thus, during these experimental conditions, the heart seems to cope very well with the increased osmotic load.

Lipid infusion in critically ill patients. Acute effects on hemodynamics and pulmonary gas exchange

Hemodynamics, pulmonary diffusing capacity (DLCO) blood gases, oxygen consumption (VO2) and carbon dioxide excretion (VCO2) were studied in healthy volunteers and ventilator-treated, critically ill patients before and during infusion of lipid emulsion for 4 h. Triglyceride levels rose from 1.0 mmole/L to 8.5 mmole/L in the volunteers and from 1.4 mmole/L to 6.3 mmole/L in the patients after h. No adverse effects on cardiovascular performance were observed. Increases in VO2, and VCO2 and cardiac output were found in both groups, while RQ remained constant. No changes in DLCO and blood gases occurred.

A comparison between the influence of halothane or fentanyl and droperidol anaesthesia on the adrenergic receptor response in human adipose tissue in vitro

A comparison was made between the adrenergic receptor response in vitro in human adipose tissue obtained under halothane and neuroleptanaesthesia. In both groups the net release of glycerol was significantly stimulated (P less than 0.01) by the combined alpha- and beta-adrenergic agonist, 1-noradrenaline. In the halothane group, the lipolysis was further increased by the addition of phentolamine (an alpha-adrenergic blocking agent). No such effect could be demonstrated in specimens from the fentanyl/droperidol group. This difference in response was most probably explained by the fact that droperidol had quite a long-lasting alpha-adrenergic blocking property, which totally obliterated the effect of another alpha-adrenergic blocking agent. The findings stress the importance of using a standardized procedure, including the choice of anaesthetic agents, when human adipose tissue is sampled for metabolic studies in vitro. The results also indicate the possibility of a difference in metabolic effects in vivo between the two procedures.