Carboxyl ester lipase (bile salt-stimulated lipase), colipase, lipase, and phospholipase A2 levels in pancreatic enzyme supplements

BACKGROUND

Pancreatic lipolytic activity originates from lipase (LIP) and its cofactor colipase (COL), carboxyl ester lipase (CEL), and phospholipase A2 (PLA2). Yet there are few data on the levels of individual lipolytic enzymes in pancreatic enzyme supplements (PES). This study determines activity and immunoreactive mass in some commonly used PES and thus contributes to the understanding of the poor relationship between 'lipase dose' and clinical improvements.

METHODS

Recommended doses of each PES were incubated at 37 degrees C for 2 h in a 1-mM Tris-maleate buffer, pH 7.0, containing 150 mM NaCl and 1 mM CaCl2. Aliquots for determinations of enzyme activities and for immunochemical mass were taken every half hour. For comparison a standard dose was defined as 10,000 declared lipase units.

RESULTS

No simple parallelism between LIP, COL, CEL, and/or PLA2 activities was seen. The LIP contents ranged from 135% to 301% of the standard dose. None of the PES were short of COL (227%-504%). The variation in CEL was twentyfold, and in PLA2 sevenfold. Less variations were seen in the mass composition. There was considerable variation in activity to mass ratios (particularly for CEL), declared lipase units per recommended dose (6000-160,000), and cost (0.36-3.52 SEK).

CONCLUSIONS

PES differ considerably in their content of lipolytic enzymes. CEL activities were relatively low and COL and PLA2 activities high compared with normal duodenal content. The manufacturing procedure can be improved to increase the lipolytic activity in PES in a broader meaning. It seems to be most important to increase the amount of CEL. From these in vitro data we advocate a more careful decision in the choice of PES for each patient, depending on the total clinical picture. Money can be saved without disadvantage to the patient.

Impaired B cell maturation in mice lacking Bruton's tyrosine kinase (Btk) and CD40

Mutations in Bruton's tyrosine kinase (Btk) gene, in mice, result in reduced numbers and responses of peripheral B cells. Surface Ig-mediated signaling is defective in Btk mutant B cells as they do not proliferate upon slg cross-linking and lack thymus-independent (TI) type II responses. Signals through sIg and CD40 play a critical role in B cell maturation. To investigate the consequences of the lack of both Btk and CD40 on B cell development and function, mice were generated that were homozygous for targeted mutations in the Btk and the CD40 genes (BtkMCD40M). The CD40 mutation (CD40M) had a synergistic effect on the BtkM defects. In BtkMCD40M mice the number of B cells was reduced 3- to 4-fold compared to BtkM mice and mature B cells (IgMlow/IgDhigh) were virtually absent; serum levels of all Ig isotypes were diminished; and antibody responses to TI-I TI-II and thymus-dependent antigens were impaired. Furthermore, although wild-type BtkM and CD40M mice produced germinal centers in response to TI-I antigen, the BtkMCD40M mice did not. Maturational and functional B cell defects in BtkMCD40M mice may result from a combination of intrinsic B cell defects, lack of CD40L-dependent T cell help and microenvironmental defects. These data suggest that signals through Btk and CD40 are necessary for the production and maintenance of the mature B cell.

The effect of glycaemic control and the introduction of insulin therapy on retinopathy in non-insulin-dependent diabetes mellitus

To study the progression of diabetic retinography in relation to diabetes treatment and glycaemic control in patients with non-insulin dependent (Type 2) diabetes mellitus (NIDDM), we performed a prospective study in a cohort of 1378 diabetic patients, aged > or = 40 years at diagnosis, of whom 333 were treated with insulin, and 1045 with oral antihyperglycaemic agents or diet alone. In the latter group 174 patients changed to insulin therapy during follow-up. We used the Wisconsin scale to grade retinopathy, recorded blindness (visual acuity < or = 0.1) and visual impairment (visual acuity 0.2-0.4), and measured the average HbA1c for each patient during a mean 3.1 year study period. In a multivariate analysis, patients who changed treatment from oral agents or diet alone to insulin therapy had a relative risk of 2.0 (95% confidence interval 1.7-2.3) for progression of retinopathy > or = 3 levels compared with all other patients in the study. The increase in risk remained even after controlling for mean HbA1c (relative risk 1.6; 95% confidence interval 1.3-1.9). Progression > or = 3 levels was significantly associated with a higher incidence of macular oedema and deterioration of visual acuity (p < 0.001). The relative risk for blindness/visual impairment due to retinopathy was 2.7 (95% confidence interval 1.8-4.0) in the group with changed treatment compared with all the other patients in the study. Poor glycaemic control (Hba1c%) before the start of insulin therapy and any retinopathy at baseline were significant risk factors for progression in the group with changed treatment (both p < 0.01). In the whole study group, poor glycaemic control was significantly associated with retinopathy progression > or = 3 levels; the relative risk for those having mean HbA1c above the median being 1.7 (95% confidence interval 1.4-2.1), compared to those with a HbA1c value below the median. Moderate non-proliferative diabetic retinopathy at baseline was also associated with progression (relative risk 2.5; 95% confidence interval 1.4-4.5). In contrast, insulin treatment at baseline was not associated with an increased risk of retinopathy progression. In conclusion, while hyperglycaemia was a risk factor for the progression of retinopathy in all patients, change of treatment from oral drugs to insulin was associated with a 100% increased risk of retinopathy progression and a 3-fold increased risk of blindness/visual impairment.

Modelling the volume of expandable body fluid spaces during i.v. fluid therapy

We have developed mathematical models to represent the changes in volume of fluid spaces associated with i.v. administration of a crystalloid solution. Input data for parameter estimations were dilution of blood, measured as reduction of blood haemoglobin concentration. The models were based on the assumption that the body strives to maintain volume homeostasis of fluid spaces and that the rate of restoration is a function of deviation from resting volume. Two models were derived; the first had a single fluid space into which fluid was administered and from which fluid left, the other model had a second fluid space communicating with the first. These models may be useful in the description and analysis of the effects of i.v. fluid therapy.

Retinyl ester storage is altered in liver stellate cells and in HL60 cells transfected with cellular retinol-binding protein type I

It is suggested that cellular retinol-binding proteins are important for intracellular metabolism of retinol. Retinol bound to cellular retinol-binding proteins may be esterified with long chain fatty acids by the enzyme lecithin: retinol acyltransferase or may be oxidized to retinoic acid metabolites used in the mechanism of action of vitamin A. The aim of this present report was to determine whether altered levels of cellular retinol-binding protein type I influenced retinol storage and activation. Two different cell types have been examined after transfection with vectors producing sense or antisense mRNA for cellular retinol-binding protein type I. When HL60 cells were transfected with the expression vector for sense cellular retinol-binding protein type I high amounts of cellular retinol-binding protein type I mRNA and protein were produced. We observed that HL60 cells esterified less retinol than control cells without cellular retinol-binding protein type I. Cellular retinol-binding protein type I had, however, no effects on the proliferation or differentiation of HL60 cells by retinoids. Liver stellate cells transfected with the vector for sense cellular retinol-binding protein type I esterified more retinol than cells transfected with the expression vector for antisense cellular retinol-binding protein type I, while retinol esterification in control cells was intermediate. In conclusion, our data show that cellular retinol-binding protein type I influences retinol esterification both in liver stellate cells and in HL60 cells.

Long-chain saturated fatty acids can be alpha-oxidised by a purified enzyme (M(r) 240,000) in cucumber (Cucumis sativus)

An enzyme (M(r) 240,000) with high fatty acid alpha-oxidation activity has been purified from the fruit of cucumber (Cucumis sativus). The specific alpha-oxidation activity in the purified fraction was 370 nmol/min per mg protein determined as liberation of 14CO2 from [1-14C]palmitic acid. alpha-Oxidation activity was observed both in the 12,000 x g pellet and 150,000 x g pellet by differential fractionation of cucumber homogenate. The enzyme was purified about 220-fold to near homogeneity from a 12,000 x g fraction by solubilisation with Triton X-100R, ammonium sulphate precipitation, hydrophobic interaction and anion-exchange chromatographies and Superose 12 gel filtration. The molecular mass of the native enzyme was 240,000, and the major subunit molecular mass of 40,000 indicated an oligomeric structure.

Intralipid rapidly attenuates the agonist-induced activation of rat platelets in vitro

This study examines the uptake of Intralipid by rat platelets and the effect of Intralipid on platelet activation and platelet lipid composition in vitro. 3H-cholesteryl hexadecyl ether labeled Intralipid (3H-Intralipid) was incubated with rat platelets for up to 4 hours. A significant uptake of 3H-Intralipid occurred as indicated by the increase of 3H in platelets with time. Addition of unlabelled Intralipid or chyle chylomicrons decreased the uptake of labeled Intralipid by the platelets, whereas Intralipid had less effect on the uptake of 14C linoleic acid labeled chylomicrons. Incubation of rat platelets with Intralipid caused a dose dependent inhibition of ADP, collagen and thrombin induced platelet aggregation and serotonin release. Both an attenuated response and a reduction of platelet cholesterol contents was seen within 10 minutes. Intralipid thus causes a rapid, dose- dependent inhibition of agonist-induced activation of rat platelets in vitro. This inhibition is linked to a loss of cholesterol and to an uptake of Intralipid particles by the platelets.

Blood haemoglobin and the long-term incidence of acute myocardial infarction after transurethral resection of the prostate

OBJECTIVES

To study risk factors for acute myocardial infarction (AMI) in men suffering from benign prostatic hypertrophy.

METHODS

We followed 811 patients who underwent transurethral resection of the prostate (TURP) between 1983 and 1992 until the end of 1993 with regard to the incidence of AMI. The association between AMI and various potential risk factors was evaluated by epidemiological methods.

RESULTS

Fifty-two patients developed a first-time AMI after TURP. A pre-operative blood haemoglobin concentration in the range of 100-129 g/l (normal range 130-165 g/l) was associated with an increased long-term relative risk of a first-time AMI, which was estimated to be 2.0 (95% confidence interval = 1.0-4.1). This estimate became slightly stronger when we also included the 76 patients with a first AMI before surgery, 10 of whom developed a re-infarction after TURP. Furthermore, it was largely unchanged on adjusting for impaired health status and age > or = 75 years (patient factors) and for fluid absorption > or = 500 ml and a blood loss > or = 275 ml (operative factors), which had been reported to increase the long-term risk of AMI in a previous study.

CONCLUSION

A moderately reduced blood haemoglobin level before TURP is associated with a doubled risk of developing AMI in later life.

Occupational exposure: Organochlorine compounds in blood plasma from potentially exposed workers. PCB, PCN, PCDD/PCDF, HCB and methylsulphonyl metabolites of PCB

Concentrations of polychlorinated biphenyls (PCB), polychlorinated naphthalenes (PCN), polychlorinated dibenzo-p-dioxins (PCDD), polychlorinated dibenzofurans (PCDF), hexachlorobenzene and methylsulphonyl metabolites of PCB were determined in blood plasma from potentially exposed workers and controls. Three of the potentially exposed subjects had worked with cable incineration and two were electricians. Extraction of the organochlorine compounds and lipids were performed using the lipophilic gel Lipidex. Different adsorbents and gel permeation chromatography were applied for further purification of the samples and separation of analytes. Determinations of the chlorinated compounds were made by using gas chromatography with electron-capture detection and gas chromatography-mass spectrometry. Only small differences in the concentrations of organochlorine compounds were found in the plasma from the three subject groups. Thus, specific exposure of the workers could not be confirmed.

Prevalence of diabetic retinopathy in relation to age at onset of the diabetes, treatment, duration and glycemic control

To study the frequency of diabetic retinopathy in relation to age at diagnosis, treatment, duration of diabetes and glycemic control as measured by means of HbA1c levels, we performed a cross-sectional, registered-based study in the Helsingborg area of southern Sweden, comprising 2232 diabetic patients. Of the known diabetic population < 75 years old, approximately 70% were estimated to be included. We graded retinopathy according to the alternative classification of the Wisconsin study. With an age at diagnosis < 30 years (19% of patients) the prevalence of retinopathy was 64%, whereas with an age at diagnosis > or = 30 years the prevalence of retinopathy was 57% in insulin-treated, and 26% in non-insulin treated patients. Levels of glycated hemoglobin and duration of diabetes were associated with retinopathy in the group with younger onset. In the older-onset group, there was a relationship between retinopathy and duration of diabetes and insulin treatment; glycated hemoglobin had a relationship which was of borderline significance with any retinopathy, but clearly significant with the pooled group: severe non-proliferative, proliferative retinopathy and/or macular edema. Hyperglycemia and duration of diabetes were thus associated with retinopathy in both younger- and older-onset diabetes, but hyperglycemia less so in the older-onset group.

Transient hypertriglyceridemia of infancy

A premature boy who had suffered from IRDS, bronchopulmonary dysplasia and retinopathy of prematurity developed massive hypertriglyceridemia (48.1 mmol/L) together with moderate hypercholesterolemia (12.6 mmol/L) at 5 months of age. Lipoprotein electrophoresis revealed a marked elevation of the level of the very low density lipoprotein fraction. There was a moderate decrease in the activity of a lipolytic enzyme, lipoprotein lipase (LPL). The child had neither liver or renal disorder nor any inflammatory disease. The hyperlipidemia disappeared spontaneously at the age of 3 years. The cause of the decreased LPL activity could not be established. A partial genetic deficiency in lipoprotein lipase appears the most likely explanation, since no signs of secondary lowering of LPL activity could be found.

Pharmacokinetics of eltanolone following bolus injection and constant rate infusion

Disposition of intravenous anaesthetic eltanolone was studied when administered as a bolus injection (B) of 0.75 mg/kg and constant rate intravenous infusion at 2 mg/kg/hr (12) and 3.5 mg/ kg/hr (13.5) for 2 hr in healthy male volunteers. Venous blood samples were collected for 12 hr and 20 hr following bolus injection and intravenous infusion, respectively. Serum eltanolone concentrations were determined by a specific gas chromatographic mass spectrometric assay. Using a nonlinear regression analysis, the individual data sets were best fitted by a three-compartment mamillary model with central elimination. Derived pharmacokinetic parameters expressed as median and 95% confidence intervals indicated an initial fast distribution with a half-life of 1.80 (0.23-5.47) min (B), 1.44 (0.97-2.06) min (12) and 1.44 (0.95-2.39) min (13.5), an intermediate phase with a half-life of 35.4 (28.7-45.2) min (B), 39.6 (31.0-47.9) min (12) and 35.4 (33.3-44.9) min (13.5) and a moderately short terminal phase with a half-life of 3.8 (2.7-5.9) hr (B), 5.0 (4.2-6.1) hr (12) and 4.6.(4.0-4.8) hr (13.5). The serum clearance after bolus injection was 1.37 (1.23-1.67) L/hr/kg and after infusion was 1.36 (1.25-1.52) L/hr/kg (12) and 1.17 (1.11-1.31) L/hr/kg (13.5). The pharmacokinetics of eltanolone appear to be linear over the dosage range studied. Pharmacokinetic parameters obtained after bolus injection were very much similar to the parameters obtained after infusion with the exception of t1/2 beta which was longer after the infusion (significant) and the volume of central compartment which was lower after infusion (not significant). Context sensitive times were estimated for a 30%, 50% and 80% drop in the concentration of eltanolone after different infusion times. A 30% drop in concentration is estimated to take about 2 to 3 min. A 50% drop in concentration is estimated to take about 8 min when duration of infusion is 3 hr and reaches a value of about 10 min by a duration of infusion of 10 hr. A 80% drop in concentration is estimated to take about 55 min following an infusion of 1 hr and it reaches a value of 70-80 min following an infusion of 10 hr.

Systemically and locally administered growth hormone stimulates bone healing in combination with osteopromotive membranes: an experimental study in rats

Growth hormone (GH) is known to be of a major importance for longitudinal bone growth, but its local effects on osteogenesis and, thus, regeneration of bone defects are less known. The aim of this investigation was to study whether GH, systemically or locally administered, has any stimulatory effects on local osteogenesis, utilizing standardized, membrane-covered, transosseous defects (5 mm diameter) in mandibles of adult albino rats. The study also addressed the question of whether GH might be a feasible option to further promote bone regeneration and neogenesis in conjunction with expanded polytetrafluoroethylene (e-PTFE) "osteopromotive" membranes (GORE-TEX). Human GH (hGH; 0.2, 2, 20, 200 micrograms/day), bovine GH (bGH; 200 micrograms/day), prolactin (200 micrograms/day) or saline was administered systemically by means of mini-osmotic pumps, implanted subcutaneously at the back of the animal. Healing was analyzed after 2, 3, and 4 weeks. Healing was also studied after local administration, just outside the defects, of hGH (0.2, 2, 20 micrograms/day) via catheters connected to mini-osmotic pumps during 4 weeks. Human GH and bGH stimulated local bone formation compared to saline and prolactin. Bone formation was significantly promoted by systemically administrated hGH, after 3 weeks and at 2 micrograms/day or higher concentrations. Enhanced bone formation was also found after 4 weeks in animals given 0.2, 2 and 20 micrograms/day of hGH locally, compared to local administration of saline. The results show that GH exerts a direct, nonliver mediated effect on bone tissue. Moreover, the study suggests that hGH may be used to stimulate bone healing and formation in conjunction with osteopromotive membranes.

Bile but not chyle lipoprotein is an important source of arachidonic acid for the rat small intestine

Arachidonic acid (AA) functions as a structural component, eicosanoid precursor and surface material for chylomicron production in the gastrointestinal tract. The origin of this AA is poorly characterized. [3H]AA labelled chylomicrons and [14C]AA albumin-FFA were injected intravenously into biliary diverted rats and controls. Radioactivity in tissue lipids was measured after different time intervals. Output of 3H and 14C in bile was 8% of the injected dose during 24 h. Radioactivity of the upper small intestine but not of colon and stomach increased with time. Bile drain reduced the recovered amounts of radioactivity in upper small intestine by 75% after 24 h. In stomach and colon 3H/g tissue was 16-20 fold lower than in liver after 24 h. Recovery of 3H in liver was higher than of 14C. In liver 3H/g tissue was 15-40 fold higher than in stomach and colon after 10-60 min. Equilibration between AA pools of liver and other organs was not complete after 96 h. Biliary phospholipid is an important source of AA for the small intestine.

Retinyl ester storage is normal in transgenic mice with enhanced expression of cellular retinol-binding protein type I

This report describes the production and characterization of transgenic mice with high expression of human cellular retinol-binding protein type I [hCRBP(I)]. In initial experiments, overexpression of hCRBP(I) was driven by the strong promoter SR(alpha), but no transgenic offspring were produced. When we used the less efficient mouse metallothionein I promoter fused to the hCRBP(I) cDNA for microinjection, we obtained 12% transgenic offspring. Two of these transgenic mice (409/1 and 401/2) expressed mRNA and immunoreactive hCRBP(I) in several organs. Both lines had relatively high contents of hCRBP(I) in intestine, testis and epididymis. On the other hand, only 401/2 transgenic mice had high contents of hCRBP(I) in kidney. Effects on storage of vitamin A were studied by measuring the concentration of retinyl esters in different organs. The concentrations of retinyl esters in liver, lung and kidney did not significantly differ between transgenic and control mice, and the concentration of total retinol in plasma was within the normal range in transgenic mice. Furthermore, feeding mice a diet with high or low concentrations of vitamin A for 2 wks resulted in no marked differences in the concentrations of retinyl esters in liver, kidney, lung, intestine and testis in transgenic mice compared with control mice. Therefore, in spite of high expression of hCRBP(I) in several organs, the transgenic mice had normal storage of retinyl esters in all organs studied. The present in vivo study indicates that the CRBP(I) content alone does not control retinyl ester storage.

Bacterial adherence and mucosal cytokine responses. Receptors and transmembrane signaling

By attaching to cells or secreted mucosal components, microbes are thought to avoid elimination by the flow of secretions that constantly wash mucosal surfaces. The attached state enhances their ability to trap nutrients and allows the bacteria to multiply more efficiently than do unattached bacterial cells. Attachment is therefore regarded as an end result in itself, and emphasis has been placed on the role of adherence for colonization of mucosal surfaces. Specific adherence was shown to be essential for the tissue tropism that is to guide microbes to their respective sites of colonization/infection. Attachment is not only a mechanism of tissue targeting but also a first step in the pathogenesis of many infections. The attaching bacteria engage in a "cross-talk" with the host cells through the mutual exchange of signals and responses. Enteropathogenic E. coli induce attaching and effacing lesions (Finley et al., this issue). Shigella and Listeria sp. invade the cells and cause actin polymerization (Sansonetti et al., this issue). This review describes the ability of bacteria to trigger mucosal inflammation through activation of cells in the mucosal lining. The results suggest that receptors for bacterial adhesins bind their ligands with a high degree of specificity and that ligand-receptor interactions trigger transmembrane signaling events that cause cell activation. Receptors for microbial ligands thus appear to fulfill also the same criteria as those used to define receptors for other classes of ligands such as hormones, growth factors, and cytokines.

A comparison between a PCR method and a conventional culture method for detecting pathogenic Yersinia enterocolitica in food

The aim of this study was to develop a polymerase chain reaction (PCR) method for the detection of pathogenic Yersinia enterocolitica and to compare it with an official culture method (NMKL-117). Primers were selected for nested PCR directed at the attachment invasion locus, ail, on the bacterial chromosome, as well as at a sequence on the pathogenic marker plasmid, termed virulence factor, virF. The final results obtained by the two methods were similar. However, while the conventional method yielded contradictory data for some steps the PCR method provided unambiguous results. Considerable advantages, i.e. higher sensitivity and specificity of the PCR method, compared with the conventional method for detecting pathogenic Y. enterocolitica, were demonstrated in this study.

Distribution of alkaline sphingomyelinase activity in human beings and animals. Tissue and species differences

The alkaline sphingomyelinase (SMase) was first found in rat intestinal brush border. The important roles of this enzyme in digestion of sphingomyelin and in mucosal cell proliferation have been suggested. In the present work, the distribution of the alkaline SMase in the tissues of human beings and animals have been studied. By assaying the enzyme activity in human biopsy samples, we found that the alkaline SMase activity was absent in the stomach, increased in the duodenum, present at high levels in the small intestine, and slightly declined in the colon and rectum. High activities were found similarly in the intestinal contents of the healthy adults and infants. The activities were also found in the intestinal mucosa of rats, normal and germ-free mice, and hamsters with the same distribution pattern as in humans, but not in the intestinal mucosa of guinea pigs. Apart from the intestinal tract, a SMase activity preferring alkaline pH was identified in human and guinea pig bile, but not in the bile of rat, pig, sheep, and cow. No activity was found in either pancreatic tissue or pancreatic juice in all species tested, and none was detected in human urine and milk. In conclusion, alkaline SMase exists predominantly in the digestive system with considerable tissue and species differences.

Pancreatic lipase-related protein 2 but not classical pancreatic lipase hydrolyzes galactolipids

The pancreatic lipase family contains three subfamilies, the 'classical' lipases and the pancreatic lipase-related proteins 1 (PLRP1) and 2 (PLRP2). Galactolipids are present in membranes of leaves and vegetables and consist of digalactosyldiacylglycerol (DGalDG) monogalactosyldiacylglycerol (MGalDG) and sulfoquinovosyldiacylglycerol (SQDG). These lipids were incubated with PLRP2 from guinea-pig (GPLRP2) and rat (RPLRP2). In the presence of bile salts DGalDG was efficiently hydrolyzed by GPLRP2 and, although less efficiently, by RPLRP2 to digalactosylmonoacylglycerol (DGalMG), free fatty acids and water-soluble galactose-containing compounds. Also, MGalDG and SQDG were hydrolyzed by GPLRP2 and RPLRP2. These data suggest a possible role of PLRP2 in the digestion of dietary galactolipids.

Essential fatty acids and abnormal involuntary movements in the general male population: a study of men born in 1933

Spontaneous and tardive dyskinesias were studied in a random population sample of 446 men, aged 59 years. Dyskinesia, defined as an AIMS score of at least 2 in any body part, was seen in 15.1% (n = 74). Dyskinetic men had a higher cigarette consumption, and they had higher frequencies of psychiatric morbidity and exposure to neuroleptics. Dyskinesia was also associated with several abnormalities in EFA concentrations in plasma, but the most consistent finding was the low arachidonic acid levels in phospholipids, triglycerides and cholesterol esters. In a logistic regression model, cigarette consumption (P < 0.02), exposure to neuroleptics (P < 0.01), and low arachidonic acid levels in the phospholipid fraction (P < 0.0001) were independently associated with dyskinesia.

How to interpret findings on mortality of long-term lithium treated manic-depressive patients?! Critique of different methodological approaches

Many studies have shown that patients with affective disorders have a mortality markedly higher than that of the general population. Studies of manic-depressive patients given prophylactic lithium treatment have yielded varying results. Some authors have reported mortalities which were more than four times that of the general population. Others have found mortalities which did not differ significantly from that of the general population. In order to examine these discrepancies we re-analysed the data of a previous study by IGSLI, using three different methods to calculate the Standardised Mortality Ratio (SMR). The data base was enlarged by adding mortality data from two additional centres. The results indicate that the discrepancies may result from the common use of a 'cumulative' approach which produces a distortion of the data if the treatment duration is not taken into consideration properly. An analysis which eliminates this artefact and takes the treatment duration into account ('year-by-year' approach) provides the strongest evidence that the mortality of lithium treated patients is not significantly different from that of the general population.

Renal function during intravenous infusion of urological irrigating fluids in the sheep

BACKGROUND

Oliguria or anuria is an important sign of the transurethral resection syndrome, but the mechanism is not clear.

METHODS

We gave an intravenous infusion of 40 ml/kg of glycine 1.5%, sorbitol 2%-mannitol 1%, and isotonic saline (control) in 6 conscious ewes and studied if irrigating fluids cause acute disturbances of kidney function.

RESULTS

Both the electrolyte-free solutions induced an increase in urine flow and persistent hypo-osmolality. The renal clearances of p-aminohippuric acid and inulin as well as the unilateral renal blood flow, which was measured via ultrasonic flow probes, increased in response to infusion of glycine but not to sorbitol-mannitol. After the infusions, the renal clearances decreased transiently to below baseline levels. Hypertonic saline was given after half of the infusions of electrolyte-free irrigating fluid. This treatment redistributed water from the cells to the extracellular fluid, but had no effect on renal function.

CONCLUSIONS

We conclude that 2500 ml of electrolyte-free irrigating fluid had no detrimental effects on kidney function in sheep. The changes we observed were essentially the same as after infusion of isotonic saline.