Current concepts of protein turnover and amino acid transport in liver and skeletal muscle during sepsis

The metabolic response to trauma and sepsis is characterized by a negative nitrogen balance, accelerated muscle proteolysis, increased ureagenesis, and stimulated acute-phase protein synthesis in liver. Inhibited uptake of amino acids and accelerated protein breakdown in muscle increase the flux of amino acids from the periphery to the liver. Concomitantly, hepatic uptake of amino acids is stimulated and protein synthesis and gluconeogenesis in the liver are enhanced. These events are important to the survival of patients with sepsis. Stimulated ureagenesis resulting in nitrogen loss from the body is another important aspect of hepatic nitrogen metabolism following trauma and sepsis. The mediator(s) initiating metabolic changes is not yet exactly defined, although regulatory protein(s) released from stimulated macrophages (particularly interleukin 1 and tumor necrosis factor) may play a major role in altered amino acid and protein metabolism in muscle and liver during sepsis. However, these factors alone are probably not responsible for the metabolic disturbances, since the catabolic hormones cortisol, glucagon, and the catecholamines can simulate the metabolic pattern observed in sepsis. Other possible mediators include prostaglandins and thyroid hormones. It is possible that the interaction between different types of mediators is necessary for the full manifestation of host responses to severe injury and sepsis.

Long saphenous vein saving surgery for varicose veins. A long-term follow-up

The autologous saphenous vein is widely recognised as the graft material of choice in infra-inguinal arterial reconstructions. This study was undertaken to evaluate the long-term results of long saphenous vein saving surgery compared with standard stripping. Forty-two patients with varicose veins were randomly allocated to treatment, either with standard stripping of the long saphenous vein or high ligation. In both groups, local varicosities were avulsed and insufficient perforators ligated, on the basis of physical examination and phlebography. Follow-up was performed 52 +/- 5 months postoperatively. The recurrence rate was 12 and 11% in the stripping and the high ligation group respectively. At follow-up, the venous return time was increased significantly in both groups (P greater than 0.001). Vein mapping by means of high-resolution, real-time ultrasound at follow-up showed that 78% of the preserved saphenous veins were suitable for use as arterial conduits. These results suggest that removal of the long saphenous vein per se is of no therapeutic value if insufficient perforators have been ligated. It is possible to perform elective vein surgery for varicose veins with good results and preserve the long saphenous vein, which in turn can be used for future arterial reconstruction in most cases.

Clinically overt hereditary hemochromatosis in Denmark 1948-1985: epidemiology, factors of significance for long-term survival, and causes of death in 179 patients

The object was to analyze, in a nationwide survey, the incidence and course of hereditary hemochromatosis in relation to the degree of iron overload and the presence of organ damage. The study included 179 Danish Caucasian patients with clinically overt hemochromatosis diagnosed between 1948 and 1985. A cohort of 158 patients was followed for a median of 8.5 years (range: 0.2-29.5). From 1951 to 1975, the yearly relative incidence rate was constant: 0.58/100,000 persons >20 years of age. From 1981 to 1985, the yearly relative incidence rate rose to 1.40/100,000 persons >20 years of age. Survival was reduced in the entire series when compared with a matched control population ( p<0.0001). There was a steady increase in survival from 1948 to 1985 ( p<0.002). Survival was significantly reduced in patients with liver cirrhosis and/or diabetes mellitus ( p<0.01). In contrast, survival in patients without cirrhosis or diabetes was similar to rates expected. Survival in patients with arthropathy was higher than in patients without joint affection ( p<0.004). Patients adequately treated with phlebotomy ( n=66) had a higher survival than inadequately treated patients ( n=62; p<0.0001). Adequately treated patients with cirrhosis and/or diabetes had better survival than inadequately treated patients with similar organ damage ( p<0.001). The main causes of death were hepatic failure due to cirrhosis (32.0%) and cirrhosis with liver cancer (23.1%). Sharpened diagnostic awareness has improved early diagnosis and increased the diagnostic frequency of clinical hemochromatosis. Adequate phlebotomy treatment was the major determinant of survival and markedly improved prognosis. Early detection and treatment of this common iron overload disorder is crucial and can completely prevent any excess mortality caused by hemochromatosis.

Small intestinal transit time and intraluminal pH in ileocecal resected patients with Crohn's disease

The pH and transit times of the gut are important for the delivery of active drug from several tablets used in the treatment of Crohn's disease (CD). Many patients with CD undergo an ileocecal resection, which might influence small intestinal pH and transit time. The effect of ileocecal resection on these variables has not previously been studied. Intraluminal pH and transit time were measured in nine ileocecal-resected CD patients and 13 healthy volunteers using pH-sensitive radiocapsules. Small intestinal transit time (SITT) was significantly shorter in ileocecal-resected patients (5.2 hr, controls 8.0 hr). The pH levels of the small intestine were identical in patients and controls, whereas cecal pH was 0.9 pH units higher in resected CD patients. The time spent with pH higher than 5.5, 6.0, 6.5, and 7.0 was significantly shorter in patients than in controls. There was no correlation between the SITT and the length of resected ileum or between the SITT and the time elapsed since the resection. We conclude that ileocecal resection decreases the SITT and the time with pH higher than 5.5-7.0. The study indicates that this reduction of the SITT is mainly due to the resection of the ileocecal valve and is, to a certain extent, independent of the length of resected ileum. An ileocecal resection might therefore affect the delivery of active drug from tablets with pH-dependent delivery.

Changes of protein metabolism in liver and skeletal muscle following trauma complicated by sepsis

The effects of trauma (laparotomy) and trauma complicated by sepsis (laparotomy and ligation and puncture of the cecum) on protein metabolism in liver and skeletal muscle were studied in rats. Unoperated animals served as controls. Rate of amino acid incorporation into proteins was determined in incubated liver slices and bundles of muscle fibers. Proteolysis in skeletal muscle was measured as release of tyrosine from incubated muscle biopsies. Protein synthesis in liver tissue was increased by 42% following trauma and by 164% following trauma and sepsis. In skeletal muscle amino acid incorporation into proteins was reduced by 50% in both conditions while protein degradation was enhanced by about 70%. Thus when injury was complicated by sepsis the metabolic response was augmented in liver but not in skeletal muscle. One reason for this difference might be that changes of protein metabolism in trauma and sepsis are regulated by different mechanisms in liver and skeletal muscle. The results also indicate that increased amino acid supply from peripheral protein breakdown is not the only signal for enhanced hepatic protein synthesis in trauma and sepsis.

Evidence that the Cys282Tyr mutation of the HFE gene originated from a population in Southern Scandinavia and spread with the Vikings

Hereditary hemochromatosis has been recognized as a clinical disorder for more than 100 years. The common form of the disorder is caused by the Cys282Tyr mutation (C282Y) of the HFE gene. Hereditary hemochromatosis affects predominantly people of Northern European origin. The C282Y mutation probably occurred on a single chromosome carrying the ancestral hemochromatosis haplotype, which subsequently was spread by emigration and the founder effect. It has been estimated that the C282Y mutation appeared 60-70 generations ago. It was initially suggested that the ancestral C282Y mutation occurred within the Celtic group of peoples. However, we hypothesize that the distribution of the C282Y mutation in Europe is more consistent with an origin among the Germanic Iron Age population in Southern Scandinavia. From this area, the mutation could later be spread by the migratory activities of the Vikings. The aim of the present study was to evaluate the validity of these two hypotheses. Several arguments are in favor of the 'Viking hypothesis': first, the highest frequencies (5.1-9.7%) of the C282Y mutation are observed in populations in the Northern part of Europe, i.e. Denmark, Norway, Sweden, Faeroe Islands, Iceland, Eastern part of England (Danelaw) and the Dublin area, all Viking homelands and settlements. Second, the highest allele frequencies are reported among populations living along the coastlines. Third, the frequencies of the C282Y mutation decline from Northern to Southern Europe. Intermediate allele frequencies (3.1-4.8%) are seen in the populations in Central Europe, which is the original Celtic homeland. Low allele frequencies (0-3.1%) are recognized in populations in Southern Europe and the Mediterranean.

Epidemiology of respiratory syncytial virus infection requiring hospitalization in East Denmark

BACKGROUND

Prophylaxis against infection caused by respiratory syncytial virus (RSV) with high titered RSV immunoglobulin or humanized antibody may soon be available in Europe.

OBJECTIVE

To study the epidemiology of RSV infections requiring hospitalization in infants <6 months in East Denmark to provide a rational basis for decisions concerning prophylaxis against RSV.

METHOD

Populat ion-based retrospective review of case records of infants <6 months admitted to pediatric departments with RSV infection in East Denmark from November 1, 1995, to April 30, 1996.

RESULTS

Data were obtained from 459 infants. Seventy-three had predisposing conditions: prematurity, 49; pulmonary disease, 2; congenital heart disease, 7; neurologic disease, 6; others, 9. One preterm infant had bronchopulmonary dysplasia. The incidence of RSV infection requiring hospitalization in East Denmark among infants <6 months was estimated to be 34/1000/season. It was 32/1000/season among term infants and 66/ 1000/season among preterm infants (P<0.001). Infants with predisposing conditions and/or nosocomial infection (n = 24) had significantly more severe courses than otherwise healthy infants (P<0.01). One-hundred thirty infants received respiratory support by nasal continuous positive airway pressure, but only six required mechanical ventilation. No infants died.

CONCLUSION

The course of RSV disease in East Denmark was milder than reported elsewhere, possibly as a result of the low prevalence of bronchopulmonary dysplasia in Denmark. However, RSV constitutes a considerable burden to the Danish pediatric health care system, and therefore prophylaxis against RSV is desirable.

Factors associated with heterotopic bone formation following total hip replacement

In order to delineate groups of patients suitable for treatment to prevent heterotopic bone formation (HBF) following total hip replacement, 99 patients were examined to evaluate predisposing factors. One year after surgery, HBF was found in 73% of the patients. A significantly increased frequency of HBF was found among men. There was no correlation between age, severity of osteoarthritis, size of osteophytes, or preoperative hip movement and HBF. Previous ipsilateral hip surgery did not increase the risk of HBF. Although not significant, all patients who developed heterotopic bone after previous ipsi- or contralateral hip surgery showed HBF of the same or even a higher grade after the present replacement.

The Value of Dihydrouracil/Uracil Plasma Ratios in Predicting 5-Fluorouracil-Related Toxicity in Colorectal Cancer Patients

This study investigated the relationship between the dihydrouracil/uracil (UH2/U) plasma ratio, a surrogate marker of dihydropyrimidine dehydrogenase (DPD) activity, and 5-fluorouracil (5-FU)-related early toxicity. Plasma UH2/U ratios were determined in 68 colorectal cancer patients and 100 healthy controls. A cutoff value indicative of DPD deficiency was calculated using receiver operator characteristics. Patients experiencing toxicity were screened for the DPD G-to-A point mutation within the 5′-splicing donor site of intron 14 (IVS14+1G>A). Overall, 24/68 patients (35%) experienced toxicity (all grades) and abnormal UH2/U ratios were demonstrated in 21/24 (87.5%) patients. Drug concentrations up to 130 times the recommended level were found in 13/24 (54%) patients experiencing toxicity. One patient experiencing toxicity was a heterozygous carrier of the IVS14+1G>A mutation. A low UH2/U plasma ratio had a sensitivity of 0.87 and specificity of 0.93 for predicting 5-FU-induced toxicity. Systematic detection of DPD-deficient patients using the UH2/U ratio could optimize 5-FU-based chemotherapy and minimize life-threatening toxicity.

Children with nutritional rickets referred to hospitals in Copenhagen during a 10-year period

AIM

To describe the prevalence of nutritional rickets among children admitted to three large paediatric departments in the Copenhagen area during a 10 y period.

METHODS

Retrospective analysis of cases identified from the diagnosis registers fulfilling the diagnostic criteria for nutritional rickets.

RESULTS

Forty cases were identified, distributed in two distinct age groups: 0.5-4 y (n = 31) and 9-15 y (n = 9). All cases were immigrants, of whom 95% were born in Denmark. The main symptoms in the younger age group were bowed legs and clumsy walk, and in the peripubertal group were painful joints. Two children had generalized convulsions. None of the cases had received vitamin D supplementation.

CONCLUSION

Nutritional rickets is still present among immigrants in Denmark, and it is likely that the prevalence of mild cases is high. Prevention through vitamin D supplementation is important, but requires a dedicated health education effort.

Nonsteroidal progesterone receptor ligands with unprecedented receptor selectivity

We have characterized a series of nonsteroidal progesterone receptor ligands, the tetrahydropyridazines. Compounds in this series, exemplified by RWJ 26819, demonstrate high affinity and unprecedented specificity for the progesterone receptor relative to other steroid hormone receptors. Like steroidal progestins, RWJ 26819 induces binding of the receptor to a progesterone response element in vitro, and stimulates gene expression in and proliferation of T47D human breast cancer cells. When administered to rabbits orally or subcutaneously, the compound induces histological changes in the uterine lining comparable to those induced by levonorgestrel. It also inhibits ovulation in monkeys. Though less potent in cells and in animal models than would be predicted from binding affinity alone, their enhanced selectivity suggests that they could be effectively used in a clinical setting. Most of the tetrahydropyridazines synthesized are progestin agonists or mixed agonists and antagonists in vitro; however, one compound with antagonist activity in the rabbit uterine transformation assay has been identified.

Cerebral response to electric stimulation of the colon and abdominal skin in healthy subjects and patients with irritable bowel syndrome

BACKGROUND

Visceral hyperalgesia may play an important part in the pathophysiology of the irritable bowel syndrome (IBS). We investigated the neuronal afferent pathways in healthy volunteers and IBS patients by recording evoked potentials (EPs) elicited by electrical stimulation of the colon and abdominal skin inside and outside the referred pain area.

METHODS

Six healthy subjects and nine IBS patients met the inclusion criteria. Morphology and topography of EPs to painful electrical stimuli were estimated in the rectosigmoid junction and on the skin inside/outside the referred pain areas.

RESULTS

The EPs to painful stimuli of the gut showed a shorter latency and a smaller amplitude of the first positive peak (P1) in the IBS group. The controls had a mid-latency frontal positive component after 100 ms, whereas no reliable early activation was seen in the IBS patients. In controls, a single late (>150 ms) positive component was seen, whereas the late component was biphasic in the IBS group. The EPs to painful stimuli of the two skin areas differed in IBS patients, but not in controls.

CONCLUSION

Differences in the EPs to electrical painful stimulation of the sigmoid colon and skin inside/outside the experimentally evoked referred pain area were seen comparing healthy subjects and IBS patients. The results indicate altered central nervous system responses.

Combined treatment with indomethacin and low-dose heparin after total hip replacement. A double-blind placebo-controlled clinical trial

We studied the safety of combining the postoperative use of a non-steroidal anti-inflammatory drug with low-dose heparin. In a double-blind, placebo-controlled clinical trial we reviewed the complications in 235 patients after total hip replacement, all treated with low-dose heparin and either indomethacin or a placebo. The incidence and type of complications in the two groups were nearly equal; indomethacin-treated patients had no increase in complications related to bleeding. Postoperative bleeding into drains was marginally greater in the indomethacin group, although the difference was not statistically significant. We conclude that treatment with indomethacin and low-dose heparin after hip replacement does not significantly increase the bleeding or other complications. We also found that patients receiving indomethacin were mobilised an average of one day before those on placebo.

A polymorphic variant in the human electron transfer flavoprotein alpha-chain (alpha-T171) displays decreased thermal stability and is overrepresented in very-long-chain acyl-CoA dehydrogenase-deficient patients with mild childhood presentation

The consequences of two amino acid polymorphisms of human electron transfer flavoprotein (alpha-T/I171 in the alpha-subunit and beta-M/T154 in the beta-subunit) on the thermal stability of the enzyme are described. The alpha-T171 variant displayed a significantly decreased thermal stability, whereas the two variants of the beta-M/T154 polymorphism did not differ. We wished to test the hypothesis that these polymorphisms might constitute susceptibility factors and therefore determined their allele and genotype frequencies in (i) control individuals, (ii) medium-chain acyl-CoA dehydrogenase-deficient patients homozygous for the K304E mutation (MCAD E304), (iii) a group of patients with elevated urinary excretion of ethylmalonic acid (EMA) possibly due to decreased short-chain acyl-CoA dehydrogenase activity, and (iv) in patients with proven deficiency of very-long-chain acyl-CoA dehydrogenase (VLCAD). No significant overrepresentations or underrepresentations were found in the first two patient groups, suggesting that the polymorphisms studied are not significant susceptibility factors in either the MCAD E304 or the EMA patient group. However, in the VLCAD deficient patients the alpha-T171 variant (decreased thermal stability) was significantly overrepresented. Subgrouping of the VLCAD patients into three phenotypic classes (severe childhood, mild childhood, and adult presentation) revealed that the overrepresentation of the alpha-T171 variant was significant only in patients with mild childhood presentation. This is compatible with a negative modulating effect of the less-stable alpha-T171 ETF variant in this group of VLCAD patients that harbor missense mutations in at least one allele and therefore potentially display residual levels of VLCAD enzyme activity.

Methods for studying protein synthesis and degradation in liver and skeletal muscle

Different methods used for measuring protein turnover in liver and skeletal muscle are described, with special emphasis on technical and practical aspects and the advantages and limitations of different techniques. In the first part of the review, the concept of precursor specific radioactivity and its importance for accurate determination of protein synthesis rate is discussed. In the second part, different in vivo techniques for protein turnover measurements are reviewed, including continuous administration of tracer amino acid, flooding dose technique, indirect measurement of protein synthesis, and estimation of protein degradation in vivo. In the third part of the report, in vitro techniques are described, including measurement of protein turnover in incubated liver slices, perfused liver, isolated hepatocytes, incubated isolated muscles or muscle biopsies, and perfused rat hemicorpus. In vivo techniques are preferred when accurate absolute values of protein turnover rates are desired. In vitro techniques offer the advantage of standardized conditions, maintaining strict control of substrate and hormone concentrations, and eliminating complicating interactions with other tissues. For several in vitro techniques, a good correlation has been demonstrated between relative changes in protein turnover in vitro and in vivo in different conditions.

Influence of ionizing radiation on nucleus 24 cochlear implants

HYPOTHESIS

To evaluate the influence of conventional or hyperfractionated radiotherapy on Nucleus CI24M or CI24R(CS) implant systems.

BACKGROUND

As a consequence of more than 70,000 cochlear implant recipients worldwide, the potential need for radiotherapy is an issue requiring consideration by both implantees and implantation centers. Conditions requiring radiotherapy of the head may include head, neck, or brain tumors.

METHODS

The study examines the effect of ionizing radiation on cochlear implant function. The implanted devices examined were the Nucleus CI24M and Nucleus CI24R(CS). In a modeled study, two implants of each type were treated with fraction schemes most frequently used in clinical routine (e.g., conventional fractionation [total dose, 120 Gy] and hyperfractionation [total dose, 116 Gy]). Parameters quantified were the implant output amplitude changes at high and low current level (current levels 255 and 100, respectively), the charge balance of the biphasic pulse, and the accuracy of the impedance telemetry function.

RESULTS

Within the clinically relevant dose range (< 80 Gy), implant function in all four devices was normal. Failure occurred in one Nucleus CI24R(CS) device treated with hyperfractionation. A dramatic drop in the output amplitude at 106 Gy was observed, and the impedance measurement failed at a total dose of 111 Gy.

CONCLUSION

The results suggest that conventional or hyperfractionated radiotherapy can be applied safely at Nucleus CI24M or CI24R(CS) implant systems in a patient-like setting. Therefore, the authors propose that the results of the study can be applicable in clinical practice.

Effect of catabolic hormone infusion on protein turnover and amino acid uptake in skeletal muscle

Increased plasma levels of the catabolic hormones glucagon, epinephrine, and cortisol have been implicated in mediating various metabolic alterations in trauma and sepsis. Their role in altered protein turnover and amino acid transport in skeletal muscle during sepsis, however, is not known. In the current study, rats were infused with a mixture of the catabolic hormones for 16 hours. Control animals were infused with vehicle solution. Protein synthesis and degradation rates were measured in incubated, intact soleus muscles as incorporation of 14C-phenylalanine into protein and release of tyrosine into incubation medium, respectively. Muscle amino acid uptake was determined by measuring the intracellular to extracellular ratio of [3H]-alpha-aminoisobutyric acid after incubation for 2 hours. Infusion of catabolic hormones for 16 hours resulted in elevated plasma glucose and lactate levels, reduced plasma concentrations of most amino acids, and accelerated muscle protein breakdown, similar to previous findings in septic rats. Protein synthesis rates and amino acid uptake in incubated muscles were not significantly different in control and hormone-infused rats. The current study suggests that increased muscle proteolysis in sepsis and severe injury may be mediated in part by catabolic hormones. In contrast, reduced muscle protein synthesis and amino acid uptake are probably signaled by other substances or mechanisms.

Infusion of a branched-chain amino acid-enriched solution and alpha-ketoisocaproic acid in septic rats: effects on nitrogen balance and skeletal muscle protein turnover

Sepsis was induced by cecal ligation and puncture in male Sprague-Dawley rats weighing approximately 70 g and the animals were intravenously infused with one of four isocaloric solutions: group I (N = 16), 8.5% dextrose solution; group II (N = 16), alpha-ketoisocaproic acid (KIA, 5.1 mg/ml) in 8.5% dextrose; group III (N = 16), FreAmine HBC (containing 45% branched-chain amino acids) in 2.5% dextrose; and group IV (N = 17), FreAmine HBC in 2.5% dextrose + KIA (5.1 mg/ml). Eighteen hr after induction of sepsis, extensor digitorum longus (EDL) and soleus (SOL) muscles were dissected with intact tendons and incubated for the study of protein synthesis and degradation, which were measured as incorporation of 14C-phenylalanine into protein and release of tyrosine into incubation medium, respectively. Urine was collected for determination of nitrogen balance. Nitrogen balance, which was equally negative in groups I and II, was significantly improved in groups III and IV and became equally positive in these groups. Protein synthesis and degradation rates in incubated EDL and SOL muscles were similar to those which we have reported previously in septic rats. Except for a higher synthetic rate in SOL in group II, no other differences in protein synthesis or degradation rates between the four experimental groups were found. Thus, the present study showed that infusion of a branched-chain amino acid-enriched solution improved nitrogen balance in septic rats. KIA alone or administered with the amino acid solution did not affect nitrogen balance.(ABSTRACT TRUNCATED AT 250 WORDS)

Feasibility of self-directed learning in clerkships

BACKGROUND

Self-directed learning has been well described in preclinical settings. However, studies report conflicting results when self-directed initiatives are implemented in clinical clerkships.

AIM

To explore the feasibility of self-directed learning stimulated by clinical encounter-cards (CECs) in clinical clerkships.

METHODS

Two focus groups of year-four and year-five students were interviewed about the usefulness of CECs to their learning in clerkships. The CECs were then introduced in two cohorts of 248 year-four and 250 year-five medical students and evaluated on a nine-point scale with regard to usefulness and feasibility.

RESULTS

The pilot groups reported that the CECs had positive effects in terms of engaging in diagnostic reasoning, reflection on management plans, and professional identity formation. However, the two large cohorts of students rated the usefulness of the CECs on learning in clerkship low (year-four: mean 2.92, SD 1.54; year-five: mean 2.28, SD 1.06) along with preceptor support (year-four: mean 2.68, SD 1.62; year-five: mean 2.59, SD 1.78, p = 0.34).

CONCLUSION

Self-directed CECs can have a positive effect on participation and clinical reasoning but are highly dependent on the context of use. Self-directed learning initiatives that aim to increase participation in communities of practice may not be feasible without major faculty development initiatives.

Protein synthesis in liver following infusion of the catabolic hormones corticosterone, epinephrine, and glucagon in rats

The mediator(s) and mechanism(s) of acute-phase protein synthesis in the liver following injury and sepsis are not fully known. Elevated plasma levels of the catabolic hormones cortisol, glucagon, and epinephrine have been reported in trauma and sepsis. In previous reports, when these hormones were infused simultaneously (triple hormone infusion), several, but not all, of the metabolic alterations characteristic of sepsis occurred. In the current investigation, the effect of triple hormone infusion on hepatic protein synthesis was studied. Rats were infused intravenously during 16 hours with a solution containing corticosterone (4.2 mg/kg/h), glucagon (2.5 micrograms/kg/h), and epinephrine (6 micrograms/kg/h). Control animals were infused with a corresponding volume of vehicle. Total hepatic protein synthesis in vivo was measured with a flooding dose technique using [14C]-leucine. The synthesis of total secretory proteins and of the individual proteins albumin, complement component C3, and alpha 1-acid glycoprotein was measured in isolated, perfused liver using [3H]-leucine and a recirculating technique. Urinary excretion of nitrogen and plasma concentration of glucose were higher and plasma total amino acid concentration was lower in hormone-infused than in control rats. Total hepatic protein synthesis in vivo, expressed as the proportion of the protein pool that was replaced each day, was increased from 39% +/- 2% per day to 48% +/- 3% per day (P less than .05) by hormone infusion, but synthesis of secretory proteins in perfused liver was not significantly altered. The results suggest that although total hepatic protein synthesis may be increased by catabolic hormones, other mediator(s) are probably responsible for the stimulation of acute-phase protein synthesis in sepsis.

Synthesis of acute-phase proteins in perfused liver following administration of recombinant interleukin 1 alpha to normal or adrenalectomized rats

The purpose of this study was to investigate the effects of recombinant interleukin 1 alpha (rIL-1 alpha) on metabolic rate and synthesis of acute-phase proteins in intact and adrenalectomized rats. Animals were housed in metabolic cages with daily recording of food intake and body weight. Twice daily, for 3 days, the rats were injected intraperitoneally with 5000 LAF U of human rIL-1 alpha, purified from Escherichia coli. Control animals were pair-fed and received corresponding injections with saline. In the morning of the fourth day, resting energy expenditure (REE) was determined by indirect calorimetry, and synthesis of total secreted proteins, albumin, complement component C3, and seromucoid fraction was measured by radioimmunological method using rat-specific antisera and [3H]leucine in livers perfused for 2 hr. Food intake decreased by approximately 30% during rIL-1 alpha administration to intact rats. The decrease in food intake occurred later and was less pronounced in adrenalectomized rats receiving rIL-1 alpha. Growth rate was significantly reduced on the first day of rIL-1 alpha treatment in intact rats, while there was no effect on growth rate in adrenalectomized animals. After rIL-1 alpha administration, REE was increased by 26% in intact rats (P less than 0.001) and by 14% in adrenalectomized rats (N.S.). Increased synthesis rates of total secreted proteins, complement component C3, and seromucoid fraction were observed in livers of intact rats following rIL-1 alpha administration. In adrenalectomized rats, only production of C3 was significantly increased after treatment with rIL-1 alpha. Albumin synthesis rate was not changed in either group following rIL-1 alpha injections.(ABSTRACT TRUNCATED AT 250 WORDS)

Oral ciprofloxacin versus intravenous cefuroxime as prophylaxis against postoperative infection in vascular surgery: a randomised double-blind, prospective multicentre study

OBJECTIVES

To test the hypothesis that oral ciprofloxacin is equally effective as intravenous cefuroxime in preventing postoperative infectious complications in patients undergoing peripheral arterial surgery involving the groins.

DESIGN

Prospective, randomised, double-blind multicentre study.

MATERIALS

580 patients undergoing arterial surgery involving the groins were randomised to ciprofloxacin (Ciproxin, Bayer) 750 mg x 2 p.o. or cefuroxime (Zinacef, Glaxo) 1.5 g x 3 i.v. given only on the day of surgery. The primary endpoint was wound/graft infection within 30 days postoperatively. Wound infection was defined as pus.

RESULTS

The wound infection rate in the ciprofloxacin group was 9.2% (27 patients) and in the cefuroxime group 9.1% (26 patients) according to intention to treat. For correct treatment the corresponding numbers were 9.5% (23 patients) and 9.7% (22 patients), respectively. There were three graft infections (0.5%). The infection rate was 7.1% (31/433) in the absence and 14.9% (22/147) in the presence of distal ulcers (p < 0.05). S. allreus was the most common bacteria isolated. Forty percent of the wound infections were localised to the groins. By multivariate analysis presence of distal ulcer was the only factor of prognostic significance.

CONCLUSIONS

The infection rate was similar in the two groups. Thus, oral administration of ciprofloxacin is an attractive, cost-effective and safe alternative to prophylaxis in vascular patients capable of taking oral medication on the day of surgery.