Tacrolimus and sirolimus have distinct effects on insulin signaling in male and female rats

Although the contribution of the immunosuppressants tacrolimus (TAC) and sirolimus (SIR) to the development of posttransplant diabetes mellitus (PTDM) are being increasingly recognized, the mechanisms of immunosuppressant-induced hyperglycemia are unclear. SIR induces insulin resistance predominantly, but is associated with β-cell dysfunction in rodents. TAC affects islet function but is associated with worsening insulin sensitivity in a few, and improvement in some, clinical studies. We sought to clarify the contributions of TAC and SIR to insulin resistance and islet function. Four groups of male and female Sprague-Dawley rats received TAC, SIR, TAC and SIR, or control for 2 weeks. All rats were administered an oral glucose challenge at the end of treatment. Half the groups were sacrificed 10 minutes after administration of regular insulin whereas the other half did not receive insulin before sacrifice. Liver, pancreas, fat, and muscle were harvested subsequently. Quantification of Western blots revealed that SIR and TAC plus SIR suppressed the phospho-Akt (pAkt)-to-Akt ratios in liver, muscle, and fat compared with control, regardless of sex. TAC alone did not impair the pAkt-to-Akt ratios in any of the tissues in male and female rats. β-Cell mass was reduced significantly after TAC treatment in male rats. SIR did not affect β-cell mass, regardless of sex. Our study demonstrated very clearly that SIR impairs insulin signaling, without any effect on β-cell mass, and TAC does not impair insulin signaling but reduces β-cell mass. Our efforts are key to understanding the mechanisms of immunosuppressant-induced hyperglycemia and to tailoring treatments for PTDM.

Vitamin D insufficiency is associated with diabetes risk in Native American children

AIMS/HYPOTHESIS

Vitamin D insufficiency has not been well studied in Native American (NA) children, who are at risk for obesity and diabetes. The authors examined vitamin D insufficiency and its association with body mass index (BMI) and insulin resistance.

METHODS

In a cross-section of NA children 5 to 18 years old (N = 198), anthropometrics, biomarkers of insulin resistance, and 25-hydroxy-vitamin D concentration [25(OH) vitamin D] were measured. BMI% and homeostatic model assessment of insulin resistance (HOMA-IR) were calculated.

RESULTS

Mean age was 10.8 ± 0.3 years (mean ± SEM). Mean serum 25(OH) vitamin D was 17.8 ± 0.4 ng/mL and 97% had vitamin D insufficiency [25(OH) vitamin D <30 ng/mL]. After adjusting for BMI, 25(OH) vitamin D was inversely associated with HOMA-IR (P < .0001) and several other markers of insulin resistance.

CONCLUSIONS/INTERPRETATION

Vitamin D insufficiency was nearly universal in this cohort of NA children and was associated with diabetes and vascular risk markers. Whether vitamin D supplementation can improve insulin resistance must be studied further.

Diabetes and cardiovascular disease following kidney transplantation

Kidney transplantation is being performed more frequently for individuals with end stage renal disease (ESRD) due to improved survival and quality of life compared to long-term dialysis. Though rates decrease after transplant, cardiovascular disease (CVD) remains the most common cause of death after kidney transplant. New-onset diabetes after transplant (NODAT), a common complication following kidney transplantation, and pre-transplant diabetes both significantly increase the risk for CVD. Several other risk factors for CVD in kidney transplant recipients have been identified; however, optimal therapy for controlling the risk factors of CVD after kidney transplantation, including NODAT and pre-transplant diabetes, is not well defined. In the following review we will discuss the role of traditional and non-traditional risk factors in CVD after kidney transplant and the mechanisms involved therein. We will also examine the current literature regarding treatment of these risk factors for the prevention of CVD. Finally, we will review the current recommendations for pre- and post-transplant cardiovascular evaluation and management.

Do subjective cognitive complaints correlate with cognitive impairment in systemic lupus erythematosus? A Danish outpatient study

This study examined the prevalence of cognitive impairment and its association with depressive symptoms and self-reported cognitive complaints in Danish outpatients with systemic lupus erythematosus (SLE). Fifty-seven consecutive female SLE-outpatients were examined with a comprehensive neuropsychological test-battery, a 20-item self-administered Perceived Deficits Questionnaire (PDQ) and a self-rated depression scale (Major Depression Inventory). Twenty-two patients (38.5%) were classified as cognitively impaired, mostly with deficits in executive functions and attention. Among cognitively impaired patients only 18.2% had significantly higher PDQ scores than the normal range. PDQ scores were highly correlated to depressive symptoms (r = 0.67, p < 0.001). Only two neuropsychological tests were significantly correlated with subjective cognitive complaints. When these variables and self-rated depression score were entered into a regression model both depression score and Symbol Digit Modalities Test performances were significantly associated with the PDQ score. In conclusion, cognitive impairments were common in this group of (mild) SLE outpatients, but the level of significant subjective cognitive complaints was low even among patients with cognitive impairment. Affective status may influence subjective experience of cognitive functions even more than cognitive functioning itself, and absence of subjective cognitive complaints did not exclude the presence of cognitive impairments.

Body mass index percentile more sensitive than acanthosis nigricans for screening Native American children for diabetes risk

BACKGROUND

Many Native American tribes use acanthosis nigricans to screen for type 2 diabetes risk. We hypothesized that acanthosis nigricans misses many children at risk for type 2 diabetes.

METHODS

We evaluated 5- to 18-year-old Native American children and youth to assess the sensitivity and specificity of acanthosis nigricans as a marker for insulin resistance.

RESULTS

In a cohort of 161 youth (72 males/89 females), mean age was 10.7 years + 3.9. Mean body mass index (BMI) percentile was 76.8 +/- 23.3, and 54% had a BMI at or above the 85th percentile. Acanthosis nigricans was present in 21.7% of the participants and was more common in 12-to 18-year-olds than in 5 to 11-year-olds (p = .02). Of those with acanthosis nigricans, 82.4% had insulin resistance (homeostatic model assessment of insulin resistance >4), but only 48.3% of those with insulin resistance had acanthosis nigricans. In contrast, BMI at or above the 85th percentile had a high sensitivity (74%) for insulin resistance, even though its specificity was lower (58%).

CONCLUSIONS

The presence of acanthosis nigricans alone was a specific, but not a sensitive, screening tool for identifying youth with insulin resistance. BMI at or above the 85th percentile was a more sensitive screening tool than acanthosis nigricans alone, or acanthosis nigricans and BMI together for identifying children and youth with IR who are at increased risk for type 2 diabetes.

Agglutination Typing of Vibrio anguillarum Isolates from Diseased Fish and from the Environment

Agglutinating activity was widely distributed among 101 Vibrio anguillarum strains of different origin and three Vibrio ordalii strains from salmonids. The spectrum of cells which were agglutinated comprised yeast cells and human (type O), poultry, guinea pig, and trout erythrocytes, whereas ovine, bovine, and tanned bovine erythrocytes were not affected. Mannose-sensitive hemagglutination, mannose-resistant hemagglutination, and non-agglutinating strains were recognized. The three V. ordalii strains showed mannose-resistant hemagglutination, whereas V. anguillarum exhibited either mannose-sensitive hemagglutination or was non-agglutinating. Among V. anguillarum, sensitivity to d-galactose and l-fucose occurred sporadically. An agglutination typing scheme was developed for strains of V. anguillarum based on the agglutination pattern of human, poultry, guinea pig, and trout erythrocytes and yeast cells. Eight different agglutination types (A through H) were defined. The distribution of these types among fish pathogenic and environmental V. anguillarum strains were studied. The application of the typing scheme in ecological and epidemiological studies and for preventive medical purposes is discussed.

Hyperglycemia induced by tacrolimus and sirolimus is reversible in normal sprague-dawley rats

Post-transplant diabetes mellitus (PTDM) worsens outcomes after kidney transplantation, and immunosuppression agents contribute to PTDM. We have previously shown that tacrolimus (TAC) and sirolimus (SIR) cause hyperglycemia in normal rats. While there is little data on the mechanism for immunosuppressant-induced hyperglycemia, we hypothesized that the TAC and SIR-induced changes are reversible. To study this possibility, we compared normal rats treated for 2 weeks with either TAC, SIR, or a combination of TAC and SIR prior to evaluating their response to glucose challenge, with parallel groups also treated for 2 weeks after which treatment was stopped for 4 weeks, prior to studying their response to glucose challenge. Mean daily glucose and growth velocity was decreased in SIR, and TAC+SIR-treated animals compared to controls (P < 0.05). TAC, SIR, and TAC+SIR treatment also resulted in increased glucose response to glucose challenge, compared to controls (P < 0.05). SIR-treated animals also had elevated insulin concentrations in response to glucose challenge, compared to controls (P < 0.05). Insulin content was decreased in TAC and TAC+SIR, and islet apoptosis was also increased after TAC+SIR treatment (P < 0.05). Four weeks after treatments were stopped, all differences resolved between groups. In conclusion, TAC, SIR, and the combination of TAC+SIR-induced changes in glucose and insulin responses to glucose challenge that were accompanied by changes in islet apoptosis and insulin content. These changes were no longer present 4 weeks after cessation of therapy suggesting immunosuppressant-induced changes in glucose metabolism are likely reversible.

Hepatitis-C prevalence in an urban native-American clinic: a prospective screening study

BACKGROUND

Native-American populations are disproportionately burdened by chronic liver disease, and the prevalence of hepatitis C (HCV) in native Americans is unknown.

PURPOSE

To determine the prevalence of hepatitis C in a local native-American population via a prospective screening study.

PROCEDURES

Two-hundred-forty-three native Americans (161 females/82 males) using an urban clinic and representing > 30 tribes from across the United States were screened. Mean age was 41 +/- 1 years. Hepatitis-C screening was by anti-HCV with confirmation by HCV RNA. A questionnaire assessed potential risk factors for HCV.

FINDINGS

Anti-HCV antibodies were found in 11.5% (95% CI: 7.5-15.5%). HCV RNA was present by polymerase chain reaction (PCR) in 8.6% (95% CI: 5.1-12.1%) and was more common in males [13.4% (95% CI: 6.0-20.8%)] than females [6.2% (95% CI: 2.5-9.9%)]. The most common potential risk factors for chronic HCV infection were intravenous (IV) drug or cocaine use (p < 0.0001), tattoos > 5 years old (p < 0.0001) and having a sexual partner with HCV (p = 0.0063).

CONCLUSION

HCV prevalence is higher in an urban native-American clinic population than reported in the general U.S. population. Use of IV drugs is the most prevalent risk factor, but tattoos and sexual transmission may also be important.

Tacrolimus and sirolimus cause insulin resistance in normal sprague dawley rats

BACKGROUND

Tacrolimus-sirolimus immunosuppression has improved islet graft survival but may affect islet function.

METHODS

We studied the effects of tacrolimus, sirolimus, or both in normal adult male Sprague Dawley rats. Glucose and insulin response to oral glucose load and pancreas pathology were evaluated after two weeks of daily tacrolimus (1-8 mg/kg/day), sirolimus (0.08-8 mg/kg/day), or low-dose sirolimus (0.08 mg/kg/day) plus tacrolimus (1 mg/kg/day) treatment compared to controls.

RESULTS

Tacrolimus and sirolimus each caused dose-dependent hyperglycemia with hyperinsulinemia in response to oral glucose compared to controls, suggesting insulin resistance. At the highest doses of sirolimus, fasting insulin concentrations were high and did not increase with oral glucose suggesting loss of first phase insulin release. The combination of low doses of tacrolimus and sirolimus, at concentrations used in clinical transplantation, resulted in hyperglycemia without hyperinsulinemia after oral glucose administration. The combination of tacrolimus and sirolimus decreased islet size, and increased islet apoptosis more than either medication alone, or controls.

CONCLUSIONS

In summary, short-term therapy with either tacrolimus or sirolimus causes insulin resistance in normal rats. Combination tacrolimus-sirolimus causes greater islet changes suggesting early islet failure.

Vibrio vulnificus serovar A: an emerging pathogen in European anguilliculture

The spread of the emerging pathogen Vibrio vulnificus biotype 2 serovar A in Danish anguilliculture is reported. Serovar A was originally isolated in a Spanish eel farm in 2000 and occurred in Denmark in the summer of 2004, affecting eels of 5-10 g body weight cultured in fresh water. The Danish eels showed clinical signs different from those reported for Spanish eels, such as severe haemorrhages in the head and gill region with necrosis of the soft tissues. Danish isolates were biochemically and serologically identical to Spanish serovar A strains and also highly virulent for eels by both intraperitoneal injection and immersion challenges. Vaccination with Vulnivaccine, a vaccine against V. vulnificus serovar E, cross-protected eels against serovar A. The LD(50) for experimentally infected vaccinated animals was significantly higher than for non-vaccinated animals.

Comparison of CT and dual-energy DEXA using a modified trunk compartment in the measurement of abdominal fat

The quantification of abdominal fat is a marker of health risk. While dual-energy x-ray absorptiometry (DEXA) is easily applied, it measures overall fat, although abdominal fat may be a better indicator of health risk from obesity. We have evaluated whether a subcomponent of DEXA measurements correlates better with computed tomography (CT) for body fat than those traditionally used. Forty-seven healthy adults (22 M/25 F), aged 54.5+/-15.8 yr (mean+/-SD), with BMI of 27.1+/-4.6 kg/m2 participated in a cross-sectional study. Body fat was measured using abdominal CT and DEXA for total fat, trunk fat, and a modified trunk measurement that excludes the chest, termed "lower trunk," and compared. The coefficient of variation for DEXA measurements for trunk, lower trunk, and total body were 1.98, 3.12, and 0.85%, respectively. Mean DEXA for percentage fat ranged from 31.7% to 34.1% for trunk, lower trunk, and total body, compared to 54.2% for abdominal CT (p<0.003 for each pairwise comparison). Lower trunk, whole trunk, and total body DEXA measurements were not different. Measurement of subcomponents of fat content by DEXA is not superior to whole body measurements and remains consistently lower than measurements by CT.

Pancreas transplantation: indications and consequences

Pancreas transplantation continues to evolve as a strategy in the management of diabetes mellitus. The first combined pancreas-kidney transplant was reported in 1967, but pancreas transplant now represents a number of procedures, each with different indications, risks, benefits, and outcomes. This review will summarize these procedures, including their risks and outcomes in comparison to kidney transplantation alone, and how or if they affect the consequences of diabetes: hyperglycemia, hypoglycemia, and microvascular and macrovascular complications. In addition, the new risks introduced by immunosuppression will be reviewed, including infections, cancer, osteoporosis, reproductive function, and the impact of immunosuppression medications on blood pressure, lipids, and glucose tolerance. It is imperative that an endocrinologist remain involved in the care of the pancreas transplant recipient, even when glucose is normal, because of the myriad of issues encountered post transplant, including ongoing management of diabetic complications, prevention of bone loss, and screening for failure of the pancreas graft with reinstitution of treatment when indicated. Although long-term patient and graft survival have improved greatly after pancreas transplant, a multidisciplinary team is needed to maximize long-term quality, as well as quantity, of life for the pancreas transplant recipient.

Heel ultrasonography is not a good screening tool for bone loss after kidney and pancreas transplantation

BACKGROUND

Solid organ transplant recipients, particularly simultaneous pancreas kidney recipients, are at high fracture risk. We tested whether quantitative ultrasonography (QUS) of the heel predicts bone mineral density (BMD) by dual energy X-ray absorptiometry (DXA) in solid organ transplant recipients.

METHODS

Thirty-eight transplant recipients (22 Female/16 Male) were studied. Spine and hip BMD was measured with a Hologic DXA scanner. 'Stiffness' of the heel was measured with a Lunar Ultrasound densitometer and compared with BMD by DXA. Contributing factors to bone loss were also assessed.

RESULTS

Mean age was 43.1 +/- 1.3 yr. Simultaneous pancreas-kidney, kidney, and pancreas alone transplant recipients were assessed. Mean time post-transplantation was 3.0 +/- 0.6 yr. Mean DXA spine T-score was -1.15 +/- 0.22 (mean +/- SEM) and hip T-score was -1.22 +/- 0.20. There was no difference in mean T-score between women and men at the hip or spine. Mean right heel stiffness T-score was -0.97 +/- 0.25. There was no correlation between QUS and DXA at either the hip or spine in women or men. QUS had a false negative rate for identifying osteopenia or osteoporosis of 17% compared with DXA. The false positive rate for identifying osteopenia was 61%.

CONCLUSIONS

The QUS is an unacceptable tool for identifying those at risk for bone loss after kidney or pancreas transplantation.

Pancreas transplantation improves vascular disease in patients with type 1 diabetes

OBJECTIVE

Pancreas transplantation (PTX) normalizes glucose and improves microvascular complications, but its impact on macrovascular disease is still debated.

RESEARCH DESIGN AND METHODS

Carotid intima-media thickness (IMT), shown to correlate with cardiovascular disease (CVD) risk and events, was determined prospectively by ultrasonography in successful pancreas transplant recipients to evaluate the effect of PTX on CVD risk. Carotid IMT and CVD risk factors of pancreas transplant recipients (n = 25) were compared with three groups: individuals with type 1 diabetes without significant nephropathy (n = 20), nondiabetic kidney transplant recipients (n = 16), and normal control subjects (n = 32). Mean age of pancreas transplant recipients at the time of transplantation was 42.4 +/- 1.2 years (mean +/- SE) and duration of diabetes was 25.9 +/- 1.4 years.

RESULTS

After PTX, HbA(1c) level (P < 0.0001) decreased to normal and, whereas creatinine level (P = 0.0002) decreased, it remained elevated compared with normal control subjects (P < 0.05). Blood pressure, BMI, fasting lipid levels, smoking frequency, and use of hypolipidemic agents were unchanged. Mean carotid IMT was increased in pancreas transplant candidates but decreased by 1.8 +/- 0.1 year after PTX (P = 0.0068), no longer different from that in normal control subjects or patients with type 1 diabetes.

CONCLUSIONS

Carotid IMT improves after successful PTX within 2 years of the procedure, with normalization of HbA(1c) and improved renal function, independent of changes in lipid levels, BMI, blood pressure, smoking, or use of hypolipidemic agents. This study suggests that CVD risk, future events, and mortality should improve after PTX in the absence of other significant, untreated CVD risk factors.

Characterization of Vibrio strains isolated from turbot (Scophthalmus maximus) culture by phenotypic analysis, ribotyping and 16S rRNA gene sequence comparison

AIM

The aim of the present study was to clarify the taxonomic status of Vibrio strains isolated from an aquaculture system and to compare the results of the identifications made by phenotypic and molecular methods.

METHODS AND RESULTS

Fifty-one Vibrio strains isolated from a turbot (Scophthalmus maximus) aquaculture system were characterized by ribotyping and 16S rRNA gene sequencing. The strains had been identified phenotypically in a previous numerical taxonomy analysis as Vibrio anguillarum, V. mediterranei, V. splendidus, V. aestuarianus, V. ordalii, V. fischeri and V. scophthalmi. Cluster analysis of ribotype patterns showed that the strains were separated into two main groups: V. splendidus-V. lentus and V. scophthalmi groups. The use of 16S rRNA gene sequence allowed differentiation among V. splendidus biovar I and V. lentus strains.

CONCLUSIONS

The molecular methods identified strains of V. splendidus biovar I, V. lentus and V. scophthalmi, showing discrepancies with phenotypic characterization.

SIGNIFICANCE AND IMPACT OF THE STUDY

The molecular methods, as 16S rRNA gene sequence analysis, are necessary for the identification of phenotypically close species to avoid mis-identifications. Interestingly, this is the first report of V. lentus strains associated to turbot culture.

Recombinant mannan-binding lectin (MBL) for therapy

Mannan-binding lectin (MBL) is a plasma protein involved in the innate immune response. It binds to a number of micro-organisms and promotes killing of these through complement activation either directly or through opsonization. Clinical evidence indicates that in a variety of situations genetically determined low MBL levels are associated with increased susceptibility to infections. Infusions of plasma-derived MBL into MBL-deficient individuals was found to be safe in preliminary trials, but we considered that sufficient production and product safety could only be achieved through synthesis of recombinant MBL. A transfected human cell line produces MBL showing the same biological activity as plasma-derived MBL, and an essentially identical profile on MS. The production has been scaled up and clinical trials will start this year.

Carotid intima media thickness decreases after pancreas transplantation

BACKGROUND

Pancreas transplantation (PTX) improves diabetic microvascular complications, but it is unknown whether PTX alters macrovascular disease. Carotid intima media thickness (IMT) has been shown to correlate with cardiovascular events, so this study was designed to evaluate changes in carotid IMT after PTX.

METHODS

Four groups were studied: PTX candidates (n=60); successful PTX recipients (n=89; mean time since PTX=4.0+/-0.3 years); patients with type 1 diabetes but without nephropathy (n=20); and normal controls (n=32). Mean IMT and mean of maximum carotid IMT measurements (mean-max IMT), hemoglobin A1C, serum creatinine, body mass index (BMI), blood pressure, smoking status, use of hypolipidemic medications, and fasting lipids were determined in all groups.

RESULTS

Age, gender distribution, and BMI were not different among the groups. Duration of diabetes was also equal between pre- and post-PTX groups. Mean and mean-max IMT were greatest pre-PTX and decreased after PTX (P<0.05) to a value that was not different from controls. Hemoglobin A1C and creatinine decreased, and high density lipoprotein (HDL) increased after PTX (P<0.05), but there were no significant differences in other lipids, BMI, use of lipid lowering agents, blood pressure, or smoking status.

CONCLUSIONS

Carotid IMT is lower after PTX, suggesting a reduction in overall cardiovascular risk independent of changes in use of hypolipidemic agents, smoking, blood pressure, BMI, or lipids, except HDL. Improved carotid IMT after successful PTX predicts a reduction in future vascular disease events and suggests that the macrovascular disease of type 1 diabetes is at least partially reversible with improved glucose control.

Incidence, distribution, and spread of tetracycline resistance determinants and integron-associated antibiotic resistance genes among motile aeromonads from a fish farming environment

A collection of 313 motile aeromonads isolated at Danish rainbow trout farms was analyzed to identify some of the genes involved in high levels of antimicrobial resistance found in a previous field trial (A. S. Schmidt, M. S. Bruun, I. Dalsgaard, K. Pedersen, and J. L. Larsen, Appl. Environ. Microbiol. 66:4908-4915, 2000), the predominant resistance phenotype (37%) being a combined oxytetracycline (OTC) and sulphadiazine/trimethoprim resistance. Combined sulphonamide/trimethoprim resistance (135 isolates) appeared closely related to the presence of a class 1 integron (141 strains). Among the isolates containing integrons, four different combinations of integrated resistance gene cassettes occurred, in all cases including a dihydrofolate reductase gene and a downstream aminoglycoside resistance insert (87 isolates) and occasionally an additional chloramphenicol resistance gene cassette (31 isolates). In addition, 23 isolates had "empty" integrons without inserted gene cassettes. As far as OTC resistance was concerned, only 66 (30%) out of 216 resistant aeromonads could be assigned to resistance determinant class A (19 isolates), D (n = 6), or E (n = 39); three isolates contained two tetracycline resistance determinants (AD, AE, and DE). Forty OTC-resistant isolates containing large plasmids were selected as donors in a conjugation assay, 27 of which also contained a class 1 integron. Out of 17 successful R-plasmid transfers to Escherichia coli recipients, the respective integrons were cotransferred along with the tetracycline resistance determinants in 15 matings. Transconjugants were predominantly tetA positive (10 of 17) and contained class 1 integrons with two or more inserted antibiotic resistance genes. While there appeared to be a positive correlation between conjugative R-plasmids and tetA among the OTC-resistant aeromonads, tetE and the unclassified OTC resistance genes as well as class 1 integrons were equally distributed among isolates with and without plasmids. These findings indicate the implication of other mechanisms of gene transfer besides plasmid transfer in the dissemination of antibiotic resistance among environmental motile aeromonads.

Idiopathic hypothalamic dysfunction with precocious puberty and adipsic hypernatremia first presenting in adolescence

BACKGROUND

Idiopathic hypothalamic dysfunction is a rare syndrome that has been described in young children. This syndrome is characterized by a disturbance of thirst regulation with hypernatremia, hyperosmolarity, and altered hypothalamic function.

PATIENT REPORT

At age 6 years the reported patients presented with precocious puberty, by age 12 years she had hypernatremia presumed secondary to central diabetes insipidus and was treated with DDAVP, and at age 14 was identified to have hyperprolactinemia. At age 19 she presented with serum sodium of 185 mg/dl during an episode of illness associated with dehydration. After hydration, her sodium remained elevated. Arginine vasopressin was measurable but inappropriate to serum sodium, while urinary cyclic AMP response to vasopressin was appropriate.

CONCLUSIONS

This is the first case of precocious puberty identified in association with the more classic features of idiopathic hypothalamic dysfunction, including later-onset hypernatremia, poor thermoregulatory function, obesity, and hyperprolactinemia.

Is Aeromonas hydrophila the dominant motile Aeromonas species that causes disease outbreaks in aquaculture production in the Zhejiang Province of China?

The significance of Aeromonas hydrophila in association with disease outbreaks in aquaculture production in the Zhejiang province of China was investigated. Bacteriological examination of moribund fish and crabs resulted in 95 bacterial isolates: 88 bacterial isolates from fish and 7 isolates from crabs. PCR and traditional biochemical methods were used for identification of A. hydrophila. Out of 69 motile aeromonads, 35 isolates were identified as A. hydrophila by biochemical tests. However, 6 of those were not identified as A. hydrophila by a species specific PCR method. Serotyping revealed 2 dominant serotypes (O9 and O97) among A. hydrophila isolates. The data presented show that approximately 42% of the motile aeromonads isolated from disease outbreaks among various fish species were A. hydrophila. It is noteworthy that A. hydrophila accounted for more than 50% of the isolated aeromonands isolated from crucian carp Carassius carassius and Wuchang bream Megalobrama amblycephala with haemorrhagic septicaemia. Although this species was the most frequently isolated organism from internal organs of diseased fish and crabs in the present study, other motile Aeromonas spp. were also found. The PCR assay was useful in preventing misidentification of A. hydrophila, which may occur when only phenotypic tests are employed.

Field testing of a vaccine against eel diseases caused by Vibrio vulnificus

The field results of a vaccination programme against Vibrio vulnificus serovar E (biotype 2) in a Spanish eel farm are reported. A total of 9.5 million glass eels were vaccinated from January 1998 to March 2000 by prolonged immersion followed by 2 subsequent reimmunisations after 12 to 14 and 24 to 28 d, respectively. The acquired protection and the immune response against serovar E were estimated over a period of 6 mo after vaccination. A similar vaccination schedule was conducted with elvers in a Danish eel farm. In this case, the acquired protection and the immune response against serovar E and the new eel-pathogenic serovars, recently described in Denmark, were evaluated over a short term. The overall results show that the vaccine against V. vulnificus serovar E induces a satisfactory protective immunity during the main growth period of eels (around 6 mo) with a relative percentage survival of 62 to 86% and protects them against the new eel-pathogenic serovars. Vaccination of eels by immersion seems to be the best strategy to prevent diseases caused by V. vulnificus.

Comparison of selective media for the detection of Vibrio vulnificus in environmental samples

AIMS

To compare two selective agars, cellobiose-colistin (CC) agar and a modification of the Vibrio vulnificus medium (VVMc agar), for the isolation of Vibrio vulnificus from environmental samples.

METHODS AND RESULTS

The efficiencies of recovery of V. vulnificus collection strains on CC, VVM, VVMc and on thiosulphate-citrate-bile salts-sucrose (TCBS) agar were compared and similar efficiencies were obtained. A slightly higher recovery was observed on VVMc agar. The detection of V. vulnificus in environmental samples (eels and water) was performed by combining culture-based methods (CC and VVMc agars) with DNA-based methods using species-specific probes based on the cytolysin-haemolysin and the 16S rDNA genes. A lower accompanying microbiota was found on CC agar than on VVMc agar.

CONCLUSION

The comparison between CC and VVMc agars confirms that both are useful for the detection of V. vulnificus in environmental samples. However, the use of any of these media should be combined with a species-specific probe.

SIGNIFICANCE AND IMPACT OF THE STUDY

The combined use of a selective medium and a specific probe provides a feasible method for the detection of V. vulnificus for epidemiological and ecological studies.

In vitro interactions between rainbow trout (Oncorhynchus mykiss) macrophages and Vibrio anguillarum serogroup O2a

The sensitivity of Vibrio anguillarum serogroup O2a to killing by rainbow trout macrophages in the presence or absence of specific antibodies and complement components was evaluated using an in vitro assay. Fluorescence microscopy revealed that V. anguillarum serogroup O2a was phagocytosed by rainbow trout macrophages. In the absence of specific antibodies and complement components the bacteria were killed to a limited extent by the macrophages and there was no increased killing if the bacteria were opsonised with either antibodies or antibodies and complement. Furthermore, activated macrophages did not show enhanced ability to kill the bacteria. Vibrio anguillarum serogroup O2a were susceptible to both cell-free superoxide anion (O2-) and hydrogen peroxide (H2O2), which might be generated during the macrophage respiratory burst and the bacteria did not quench cell-free O2-. However, the production of O2- by macrophages was undetectable during the first 30 min following infection and no respiratory burst was inducible by phorbol myristate acetate (PMA) 4 h after infection with V. anguillarum. This suggests that the bacteria were able to inhibit the production of O2- by the infected macrophages. Naive fish were protected when passively immunised with anti-V. anguillarum serogroup O2a antiserum. However, previous results suggest that antibodies are unlikely to provide the fish with protective immunity directly through activation of the complement system and lysis of the bacterial cells. The present in vitro findings suggest that the protective mechanisms of antibody against V. anguillarum serogroup O2a may not involve the opsonising effect of antibodies for enhanced killing by macrophages. However, the possibility exists that such antibodies may prevent the attachment of the pathogen to the host's tissues.

Patients' views on importance and usefulness of plain radiography for low back pain

STUDY DESIGN

Quantitative and qualitative cross-sectional interview study.

OBJECTIVES

To investigate how patients who are referred for plain radiography because of low back pain perceive the importance and usefulness of the examination.

SUMMARY OF BACKGROUND DATA

Up to 50% of plain radiography examinations for low back pain may be unnecessary based on clinical criteria. However, many patients have great confidence in these examinations. A further exploration of the patients' views may indicate how their needs can be met without unnecessary use of radiography.

METHODS

Ninety-nine patients (65 women, 34 men) 14-91 years of age who were referred from Norwegian general practitioners for plain radiography of the lumbosacral spine were asked to rate the examination as slightly/fairly or very important (93 responded). Chi-squared tests were used to evaluate differences in rating according to age, gender, clinical history, and clinical appropriateness of the examination, as determined by comparing information in the referral form with Norwegian (NR) and British (BR) recommendations for use of radiography. Each of the 99 patients also underwent a semistructured interview that was based on questions about importance, usefulness, and reasons for the radiography referral. Answers were categorized and described using a qualitative method (template analysis).

RESULTS

Seventy-two percent (68 of 93) of patients rated radiography as very important. The proportion was higher for men than women (85% vs. 65%, P = 0.04), higher for those with worsening than those with improving/unchanged symptoms (86% vs. 65%, P = 0.03), and higher for inappropriately than appropriately referred patients (NR: 76% vs. 61%, P = 0.17; BR: 81% vs. 56%, P = 0.01). The qualitative analysis showed that the patients related their views on the importance and usefulness of receiving radiography to seven different issues: symptoms and clinical history, information and advice (especially from health care providers), need for emotional support from the physician, need for certainty and reassurance, need for symptom explanation and diagnosis, reliability of radiography compared with clinical evaluation, and expected practical consequences of the radiologic examination.

CONCLUSIONS

The finding that inappropriately referred patients tended to rate their radiography referral as more important than appropriately referred patients indicates that the patient's view may be a substantial barrier to appropriate use of radiography. The study identified seven issues underlying the patients' views on importance and usefulness of receiving radiography. Strategies to prevent unnecessary use of plain radiography for low back pain that address these issues are suggested.

Characterization of class 1 integrons associated with R-plasmids in clinical Aeromonas salmonicida isolates from various geographical areas

Class 1 integrons were found in 26 of 40 antibiotic-resistant isolates of the fish pathogen Aeromonas salmonicida from Northern Europe and North America. Three different dhfr genes, conferring trimethoprim resistance, and one ant(3")1a aminoglycoside resistance gene were identified as gene inserts. The gene cassettes tended to be conserved among isolates from a particular geographical area. Nineteen isolates transferred R-plasmids carrying different tet determinants to Escherichia coli in filter mating assays, and in 15 cases, the class 1 integrons were co-transferred. Transferable sulphadiazine, trimethoprim and streptomycin resistances were invariably encoded by integrons. It thus appears that integron-encoded antibiotic resistance genes contribute substantially to the horizontal spread of antimicrobial resistance within this species, being associated with conjugative plasmids.

Lipoatrophic diabetes and end-stage liver disease secondary to nonalcoholic steatohepatitis with recurrence after liver transplantation

BACKGROUND

Lipoatrophic diabetes is an insulin resistance syndrome characterized by the complete or partial lack of adipose tissue and disturbances in lipid and glucose metabolism. Nonalcoholic steatohepatitis (NASH) is a well-described change in liver pathology consisting of steatosis, hepatitis, and fibrosis that can be associated with lipoatrophic diabetes.

RESULTS

This article describes the first reported case of lipoatrophic diabetes with NASH leading to liver failure and liver transplantation. Before transplantation, the patient required 600-700 U of insulin/day. After transplantation, a dramatic decline in her insulin requirements was observed, despite corticosteroids. Eighteen months after transplantation, her glycemic control worsened, and she developed recurrent NASH on serial liver biopsies.

CONCLUSIONS

NASH associated with lipoatrophic diabetes can recur after liver transplantation, and in this case, was accompanied by increased insulin requirements. These results suggest that the development of NASH itself may contribute to the insulin resistance observed in lipoatrophic diabetes.

Acoustic neuroma--treatment modalities. Surgery, gamma-knife or observation?

We present our results of 211 patients with acoustic neuroma over a period of 10 years, 1988-97. We operated on 100 and 111 had Gamma-knife (GK) treatment (69 were available to follow-up). The results are excellent for surgery on small and intracanalicular tumours. In tumours of the same size, surgery and GK treatment give comparable, but somewhat different, results. In the GK group of 54 primary treated patients, 3 patients had to be operated on and another 4 developed hydrocephalus. A group of 35 acoustic tumours was observed for more than 3 years. Nineteen did grow (54%). Hearing was unchanged in 23%. We performed surgery in 11 patients and gave 2 patients GK treatment because of tumour growth of > 2 mm in diameter a year. We conclude that either treatment is effective for small and medium-sized acoustic neuromas. Hearing preservation was best in the GK-treated group (80%), compared to only 12.5% in the group operated via the suboccipital route. Larger tumours and most medium-sized tumours should be operated, as should smaller tumours with persistent symptoms of vertigo and pain. Medical contraindications to surgery or reluctance to undergo surgery make GK treatment a good alternative. Treatment of residual tumours with the GK could also be a solution to a difficult problem.

Cyclosporine challenge test revisited: does it predict outcome after solitary pancreas transplantation?

BACKGROUND

The selection of patients for solitary pancreas transplantation (PTA) requires identification of individuals who will not develop acute renal dysfunction in response to immunosuppressants. A cyclosporine challenge test (CCT) was developed to predict post-PTA kidney dysfunction secondary to calcineurin inhibitor immunosuppressants. We now report on the long-term follow-up of patients who received a PTA after undergoing a CCT.

METHODS

Twelve potential PTA recipients were administered cyclosporine A (CsA) for 6 wk. Creatinine clearance (CrCl) was measured at 2, 4, and 6 wk. Those who did not fail the CCT received PTA. Baseline and post-transplant CrCl were retrospectively evaluated in the original cohort and in a group of matched patients who received PTA without a CCT.

RESULTS

Of the original 12 recipients evaluated with the CCT, 6 received PTA. CrCl was followed for a mean of 45.8 months. Of the 4 who remained alive, 2 went on to develop renal failure (CrCl < 30 mL/min) at 18 and 65 months post-transplant. The baseline CrCl was higher in PTA recipients who had not been selected to be studied with CCT than those that were (117 +/- 32 vs 78 +/- 13 mL/min). By 12 months post-PTA, the CrCl was no longer different between the groups selected to be screened with CCT and those that were not.

CONCLUSIONS

CCT may help predict risk for short-term changes in renal function (< 18 months) in response to CsA. CCT may be most helpful in candidates for PTA with borderline renal insufficiency (60-80 mL/min).

[How are radiographic examinations documented in medical records?]

BACKGROUND

In order to improve the quality of our activity at the Department of Radiology, Haukeland University Hospital, we investigated how the referring clinical departments registered the results from diagnostic imaging.

MATERIAL AND METHODS

We made a prospective registration of all hospitalized patients who received one or more diagnostic imaging or interventional procedures during a 24-hour period. Starting three months later, we performed a survey of how the radiological reports had been recorded by the referring departments.

RESULTS

Results from 11 of a total of 177 examinations (6%) could not be found in the medical records. Altogether 67 examinations (38%) were not mentioned even as a note in the patient files, and 57 examinations (32%) were not mentioned in the final report at discharge.

INTERPRETATION

In our opinion this study demonstrates a considerable potential for improvement in making important information more available to doctors, in the hospital and in general practice.

[Patients' knowledge of the effects of X-rays]

BACKGROUND

Exposure to radiation from different non-medical sources in the community is given more attention in the media. The effects of radiologic examination, however, seldom receive the same amount of interest.

MATERIAL AND METHODS

295 patients were interviewed immediately after an X-ray examination at Haukeland Hospital to investigate what they knew about the effects of X-rays on the human body. In addition we wanted to find out whether referring doctors had informed their patients about possible unwanted effects of the radiological examination.

RESULTS

The patients were more aware of possible effects of radiation from high-voltage cables than of the effects from X-raying. Only three patients had been informed by their referring doctors that X-ray examination could have unwanted effects.

INTERPRETATION

Information to patients about diagnostic radiation should be improved.

Occurrence of antimicrobial resistance in fish-pathogenic and environmental bacteria associated with four danish rainbow trout farms

Surveillance of bacterial susceptibility to five antimicrobial agents was performed during a 1-year period in and around four freshwater fish farms situated along a stream in western Denmark. Besides assessing the levels of antibiotic resistance among the culturable fraction of microorganisms in fish, water, and sediment samples, two major fish pathogens (88 Flavobacterium psychrophilum isolates and 134 Yersinia ruckeri isolates) and 313 motile Aeromonas isolates, representing a group of ubiquitous aquatic bacteria, were isolated from the same samples. MICs were obtained applying a standardized agar dilution method. A markedly decreased susceptibility of F. psychrophilum isolates to most antimicrobial agents presently available for use in Danish aquaculture was detected, while the collected Y. ruckeri isolates remained largely sensitive to all therapeutic substances. Comparing the inlet and outlet samples, the increase of the antibiotic-resistant proportions observed among the culturable microflora was more pronounced and statistically significant among the motile aeromonads. High levels of individual and multiple antimicrobial resistances were demonstrated within the collected flavobacteria and aeromonads, thus indicating a substantial impact of fish farming on several groups of bacteria associated with aquacultural environments.

Reproductive hormones after pancreas transplantation

BACKGROUND

Reproductive hormone function after pancreas transplantation (PTX) is unknown as it has not been studied.

METHODS

We prospectively studied PTX recipients to determine changes in reproductive hormones after PTX. Testosterone or estradiol, leutinizing hormone, follicle stimulating hormone, and prolactin were determined before and 1 year after PTX in 23 patients (10 women, 13 men) followed for more than 1 year after PTX. Of these, 11 received simultaneous kidney-PTX; 8 PTX only; and 4, PTX after kidney. Average age was 38.4+/-1.6 years and average duration of diabetes was 24.5+/-1.3 years. Nine (four women, five men) patients had been on dialysis pre-PTX. Sixteen of 23 patients were treated with cyclosporine and seven with FK-506 along with prednisone and azathioprine post-PTX.

RESULTS

Mean testosterone in men was normal pre- and post-PTX. Two men had secondary hypogonadism pre-PTX with resolution in one and persistence in the other post-PTX. Five of the ten women had evidence of hypogonadism pre-PTX: three had primary hypogonadism and two had secondary hypogonadism. Post-PTX, 7 of 10 women had abnormal reproductive hormones: 4 had primary hypogonadism, 2 had secondary hypogonadism, and 1 developed hyperestrogenemia with elevated estradiol (482 pg/ml) and leutinizing hormone (41 IU/liter). Mean prednisone dose and cyclosporine trough level were higher in the women than the men (P<0.05). No cases of secondary hypogonadism that developed or resolved post-PTX were related to changes in prolactin, renal function, or hyperglycemia.

CONCLUSIONS

Women are more likely than men to have reproductive hormone abnormalities pre- and post-PTX and the causes may be multiple.

Pulsed-field gel electrophoriesis analyis of Aeromonas salmonicida ssp. salmonicida

A total of 133 strains of Aeromonas salmonicida ssp. salmonicida, isolated from a wide variety of sources, were characterized by pulsed-field gel electrophoresis patterns. Sixteen profiles were demonstrated, with one profile being predominant in samples from all the countries and species of fish. Our results suggest a clonal distribution of this subspecies, with a predominant clone being responsible for most of the outbreaks worldwide.

[Radiography of the lumbosacral spine--do the referrals conform to clinical recommendations?]

The aim of this study was to evaluate how referrals from Norwegian general practitioners for plain radiography of the lumbosacral spine conform to clinical recommendations. The clinical information given in 274 referral letters was compared with Norwegian and British recommendations. We also interviewed 99 of the patients about symptoms and prior radiographs, and performed a new comparison using all available information. Only 27% (43%) of the 274 referrals conformed to the Norwegian (British) recommendations, 36% (41%) did not conform, and 37% (16%) were considered uncertain, mainly because of lack of pertinent information in the referral letters. Of 143 referrals which were in disagreement with the Norwegian and/or the British recommendations, only four resulted in "important" findings (osteoporotic fractures in two patients, uncertain sacroiliac joint arthritis in one patient, and probably benign bony sclerosis in one patient). In the interview group, the proportion of non-conforming referrals decreased from 40% (47%) to 31% (29%) when the additional clinical information was considered. Nevertheless, we conclude that a substantial proportion of referrals for plain radiography of the lumbosacral spine do not conform to clinical recommendations. Referrals outside the advised criteria yield few relevant findings and could probably be cancelled.

Characterization by numerical taxonomy and ribotyping of Vibrio splendidus biovar I and Vibrio scophthalmi strains associated with turbot cultures

Twelve Vibrio strains were examined phenotypically in 91 biochemical characters and genotypically by ribotyping. Ten were isolated from sea water and two from diseased turbot (Scophthalmus maximus). All isolates originated from one experimental system located in Ría de Vigo (Galicia, north-west Spain). Different type strains were used for comparative purposes. The taxonomic position was analysed with the NTSYST-pc and similarities among strains were calculated by the Simple Matching coefficient (SSM). rRNA gene restriction patterns were performed with the HindIII enzyme. The SSM coefficient separated the 12 Vibrio strains into two groups which included strains that showed a SSM coefficient quite similar to V. splendidus biovar 1 (ATCC 33125) and V. scophthalmi (CECT 4638). None of 91 phenotypical characters were specific in distinguishing both species. The ribotyping confirmed the taxonomic classification of strains. The pathogenicity of each strain was evaluated; 10 environmental strains were avirulent and two, isolated from diseased turbot, were virulent. Different biotypes and ribotypes were found among the avirulent isolates. This work showed ribotyping to be a valuable tool for identification and confirmed the necessity of extending the ribotype database within closely related Vibrio species in order to clarify the taxonomic position.

Colon cancer at barium enema examination and colonoscopy: a study from the county of Hordaland, Norway

PURPOSE

To evaluate the efficacy of barium enema examination as routinely performed in the detection of colon cancer in the inhabitants of a well-defined and circumscribed geographic region.

MATERIALS AND METHODS

The study comprised 571 patients with histopathologically verified colon cancer during 1990-1993 from the county of Hordaland. The barium enema examination results were reviewed retrospectively.

RESULTS

The correct diagnosis was reached in 351 cases (sensitivity, 90.9%) in 386 tumor locations on the basis of the results of 381 barium enema examinations. Cancer or an important precancerous lesion was overlooked in 26 cases (6.7%), and the examination was not feasible in nine cases (2.3%). The correct diagnosis was reached in 172 cases (sensitivity, 80.0%) in patients with 215 tumor locations on the basis of the results of 213 colonoscopies. Cancer or an important precancerous lesion was overlooked in 13 cases (6.0%). The examination was technically not successful (i.e., the affected area was not reached with the scope) in 30 cases (13.9%).

CONCLUSION

Barium enema examination is valuable in the diagnosis of colon cancer and compares favorably with colonoscopy. The main reason for missed radiologic diagnosis is failure to observe important lesions visible on the radiographs.

Extended serotyping scheme for Vibrio anguillarum with the definition and characterization of seven provisional O-serogroups

The present paper summarizes the serotyping scheme of the fish pathogenic bacterium Vibrio anguillarum and defines seven additional O-serogroups. Strains, collected in our laboratories that were nontypable with antisera against the previously defined 16 O-serotypes, were used for generating new antisera and were characterized further by means of LPS profiles, Western blots, and serological reactions. On the basis of the results, it is suggested that the seven new O-serogroups are to be included in the existing serotyping system as serotypes O17-O23. However, the existence of further V. anguillarum strains that were not typable with any of the 23 O-antisera suggested the existence of additional O-serotypes within this species. The relevance of the description of additional O-serotypes for the species V. anguillarum is discussed.

Clonality of Vibrio anguillarum strains isolated from fish from the Scandinavian countries, Sweden, Finland and Denmark

In order to investigate whether outbreaks of vibriosis in the Baltic region were caused by the spread of certain pathogenic clones, 291 Vibrio anguillarum isolates from Finland (n = 156), Sweden (n = 88) and Denmark (n = 47) were studied with respect to serogroup, ribotype, plasmid content, and biochemical phenotypes as expressed with the PhenePlate (PhP) typing system. For comparison, 54 V. anguillarum serogroup O1 from other countries worldwide were included. Most isolates from Finland, Sweden and Denmark belonged to serogroup O1 (255), followed by O2 (30). Four Finnish isolates cross-reacted strongly with antisera against two new serogroups VaNT2 and VaNT4, whereas two strains were non-typeable. The serogroup O1 isolates displayed ten different ribotype patterns, whereas the other strains were considerably more diverse with respect to ribotypes. Most of the O1 isolates carried the 67 kb virulence plasmid and a group of Finnish isolates, in addition, carried an 86 kb plasmid. Additional plasmids with molecular weights of 63, 76, 135 or 260-290 kb were found in single O1 isolates. With few exceptions, strains of serogroup O2 either had no plasmids or carried one or two small plasmids. PhenePlate typing revealed considerable diversity within the species, serogroup O1 being the most homogeneous. A few PhP types were dominant, whereas other types were observed only in one to four isolates. The prevalence of the different types changed significantly from one year to another but in Finland, one clonal lineage became increasingly important from 1992 (20% of isolates) to 1996 (80%). Remaining clones were mostly restricted to specific geographic areas. By cluster analysis, it was demonstrated that most of the isolates from Finland, Sweden and Denmark belonged to two clusters, and most of the strains from Southern Europe fell into two other, distinct clusters. Most isolates from the UK, North America, Chile and Tasmania grouped together in a distinct cluster. For the typing of V. anguillarum, O-serotyping should be the primary method. For isolates belonging to serogroups other than O1, plasmid profiling in combination with ribotyping gives a very good discrimination between strains, whereas for serogroup O1, another method is required. It is concluded that PhP typing is a tool that provides a good discrimination between O1 isolates.

Lipids increase after solitary pancreas transplantation

OBJECTIVE

The aims of this study were to determine 1) changes in lipids after solitary pancreas transplantation (SPTX) in patients with type 1 diabetes and 2) factors that influence those changes.

RESEARCH DESIGN AND METHODS

Lipids were evaluated prospectively in 24 patients who underwent SPTX. Three were excluded because of early graft failure. The remaining patients (n = 21; 13 men, 8 women) were studied for changes in lipids over time (pre-SPTX, 0-2, 3-6, 7-12, and > 12 months). Glycohemoglobin, serum creatinine, BMI, and medications were also analyzed for their effects on lipid changes.

RESULTS

Cholesterol, HDL, and LDL decreased in the immediate postoperative period (0-2 months), whereas triglycerides (TGs) increased (P < 0.05). At 3-6 months, cholesterol, HDL, and TG were higher than before the SPTX, whereas LDL returned to pre-SPTX levels. After 12 months, HDL and TG remained higher than their pre-SPTX levels (P < 0.05). During the study, systolic and diastolic blood pressure increased, renal function decreased, glyco-hemoglobin improved, and weight was unchanged. Changes in cholesterol/HDL ratio, HDL, and TG correlated with changes in prednisone dose (P < 0.05), and changes in TG correlated with changes in creatinine (P < 0.05). The same pattern of lipids occurred in patients prescribed or not prescribed hypolipidemic agents.

CONCLUSIONS

Lipids do not improve within the 1st year after SPTX, despite improved glycemic control and blood pressure control, and renal function is worse. These results are in contrast to those reported for combined kidney-pancreas transplantation, where lipids, blood pressure, and renal function improved immediately after transplant. Further studies are needed to determine whether lipids continue to change with time after SPTX. The impact of these changes after SPTX on overall cardiovascular risk is unknown.

Vibrio anguillarum resistance to rainbow trout (Oncorhynchus mykiss) serum: role of O-antigen structure of lipopolysaccharide

The sensitivity of Vibrio anguillarum to the bactericidal effect of rainbow trout serum was investigated with different strains of serogroups O1 and O2a, which are the most frequently found serogroups in clinical outbreaks of vibriosis. All of the V. anguillarum strains were able to activate complement in rainbow trout serum, but smooth strains of V. anguillarum serogroup O1 were resistant to complement-mediated killing in the absence of specific antibodies. In the case of V. anguillarum serogroup O2a strains, 80% of the analyzed strains were resistant to rainbow trout serum even when specific antibodies were present. Analysis of the lipopolysaccharide structures of the tested V. anguillarum strains showed a positive correlation between the O-antigen size of the lipopolysaccharide and resistance to serum killing. The classical complement pathway was responsible for the antibody-dependent serum killing of susceptible V. anguillarum strains. When serum-resistant V. anguillarum serogroup O2a strains were grown in glucose-enriched Lennox L broth, they produced lipopolysaccharide molecules with fewer high-molecular-weight O-antigen units than did strains grown in broth without the addition of glucose. Strains grown in glucose-enriched medium became sensitive to rainbow trout serum killing, indicating that the high-molecular-weight O-antigen side chains prevented the activated complement from damaging the bacterium.

Plain radiography of the lumbosacral spine. An audit of referrals from general practitioners

PURPOSE

To evaluate how referrals from Norwegian general practitioners for plain radiography of the lumbosacral spine conform to clinical recommendations, and whether non-conforming referrals yield important findings.

MATERIAL AND METHODS

The clinical information reported in referral letters of 323 patients was compared with recommendations given in a Norwegian and in a British "guide". Additional clinical data were obtained by interviewing 100 of the patients. Using all available information, a new comparison was performed. Radiological findings were obtained from the routine reports.

RESULTS

Of the 323 referrals, 24% (37%) conformed to the Norwegian (British) "guide", 34% (46%) did not conform, and 42% (18%) were considered uncertain, mainly because of lack of pertinent information in the referral letters. A total of 182 examinations were in disagreement with one or both "guides". Only 4 of these examinations revealed potentially important findings (osteoporotic fractures in 2 patients, uncertain sacroiliac joint arthritis in 1 patient, and "probably benign" sclerotic densities in 1 patient). In the interview group, the proportion of non-conforming referrals was 40% (48%) based on the referral letters, and 31% (30%) when the interview data were taken into account.

CONCLUSION

A great proportion of referrals for plain radiography of the lumbosacral spine do not conform to recent clinical recommendations. Referrals outside the advised criteria yield few relevant findings and could probably be cancelled. They require at least supplementary information to justify radiography.