The proatherogenic cytokine interleukin-18 is secreted by human adipocytes

OBJECTIVE

Interleukin (IL)-18, an important mediator of innate immunity and strong risk factor for the development of cardiovascular disease, was shown recently to be elevated in obesity. The aim of our study was to investigate whether human adipocytes produce IL-18.

METHODS

Human adipose tissue was obtained from lean women undergoing elective plastic surgery and from obese individuals undergoing laparoscopic surgery (gastric banding). Preadipocytes from mammary adipose tissue were isolated and differentiated under defined adipogenic conditions. IL-18 expression was analyzed by real-time reverse transcriptase PCR, ELISA and immunocytochemistry.

RESULTS

Human preadipocytes of all differentiation stages spontaneously secreted IL-18. In parallel significant amounts of IL-18 mRNA were detected. Freshly isolated mature adipocytes from subcutaneous and omental depots also released IL-18. IL-18 release from adipocytes from obese donors was about 3-fold higher compared to adipocytes from non-obese donors.

CONCLUSIONS

We conclude that human adipose tissue produces IL-18 and thereby contributes to systemic IL-18 concentrations. This finding supports the concepts that adipocytes behave as primitive immune cells and that IL-18 may mediate some of the detrimental complications of obesity such as cardiovascular disease and type 2 diabetes.

An immune origin of type 2 diabetes?

Subclinical, low-grade systemic inflammation has been observed in patients with type 2 diabetes and in those at increased risk of the disease. This may be more than an epiphenomenon. Alleles of genes encoding immune/inflammatory mediators are associated with the disease, and the two major environmental factors the contribute to the risk of type 2 diabetes-diet and physical activity-have a direct impact on levels of systemic immune mediators. In animal models, targeting of immune genes enhanced or suppressed the development of obesity or diabetes. Obesity is associated with the infiltration and proinflammatory activity of macrophages in adipose tissue, and immune mediators may be important regulators of insulin resistance, mitochondrial function, ectopic lipid storage and beta cell dysfunction or death. Intervention studies targeting these pathways would help to determine the contribution of an activated innate immune system to the development of type 2 diabetes.

Association of humoral immunity to human Hsp60 with the IL-6 gene polymorphism C-174G in patients with type 2 diabetes and controls

The relationship between humoral immunity to hsp60 and type 2 diabetes along with other relevant metabolic, inflammatory and immunogenetic variables was studied in 76 non-diabetic and 74 diabetic persons aged 55-74 years selected from the population-based KORA Survey 2000. Antibodies to human hsp60 were measured in serum samples by ELISA. Hsp60 antibodies were detected in all but two individuals in a considerable range of titres (22-1,856 AU/ml). There was no significant association to age and sex, or to key clinical or metabolic parameters (BMI, WHR, HbA1c, total cholesterol, LDL cholesterol, HDL cholesterol, systolic and diastolic blood pressure, albumin, uric acid) or immunological parameters (CRP, IL-6, sIL-6R, TNFalpha, sTNFalpha R60, sTNFalpha R80). Analysis of antibody-positive individuals revealed an association between hsp60 antibodies and diabetes at borderline significance (p = 0.047), which was lost when the two antibody-negative individuals were included. Genetic analyses indicated that this association was significant in carriers of the C allele of the IL-6 promoter region polymorphism at nucleotide -174 (p = 0.02), but not in GG genotype carriers. We conclude that humoral immunity to human hsp60 may be enhanced in those diabetic patients carrying the -174C allele of the IL-6 gene. This finding may contribute to an understanding of the relationship between the -174C allele and increased risk of atherosclerosis.

Heat shock protein 60: specific binding of lipopolysaccharide

Human heat shock protein 60 (HSP60) has been shown to bind to the surface of innate immune cells and to elicit a proinflammatory response. In this study we demonstrate that the macrophage stimulatory property of recombinant human HSP60 is tightly linked to the HSP60 molecule and is lost after protease treatment. However, inhibition of macrophage stimulation was reached by the LPS-binding peptide magainin II amide. Indeed, HSP60 specifically bound [(3)H]LPS. [(3)H]LPS binding to HSP60 was saturable and competable by the unlabeled ligand. To identify the epitope region of the HSP60 molecule responsible for specific LPS binding, we analyzed the effect of several anti-HSP60 mAbs on HSP60-induced production of inflammatory mediators from macrophages. We identified only one mAb, clone 4B9/89, which blocked the macrophage stimulatory activity of the chaperone. The epitope specificity of this mAb points to the region aa 335-366 of HSP60. Clone 4B9/89 also strongly inhibited [(3)H]LPS binding to HSP60. A more detailed analysis was performed by screening with selected overlapping 20-mer peptides of the HSP60 sequence, covering the region aa 331-380. Only one peptide blocked LPS binding to HSP60, thereby restricting the potential LPS-binding region to aa 351-370 of HSP60. Finally, analysis of selected 15-mer peptides and a 13-mer peptide of the HSP60 sequence revealed that most of the LPS-binding region was accounted for by aa 354-365 of HSP60, with the motif LKGK being critical for binding. Our studies identified a defined region of HSP60 involved in LPS binding, thereby implicating a physiological role of human HSP60 as LPS-binding protein.

Production and release of macrophage migration inhibitory factor from human adipocytes

BACKGROUND AND AIM OF THE STUDY

Macrophage migration inhibitory factor (MIF) has been identified as a critical mediator of inflammatory responses. Because of its potent migration inhibition activity, it regulates macrophage accumulation in tissues. We therefore analyzed whether human adipocytes produce MIF, in the search of candidate mediators of macrophage infiltration of obese adipose tissue.

METHODS

Human adipose tissue samples were obtained from various depots. The precursor cells were allowed to differentiate under defined adipogenic culture conditions. MIF expression was analyzed by RT-PCR, ELISA, and immunocytochemistry.

RESULTS

Human preadipocytes secreted MIF in a differentiation-dependent fashion with maximum concentrations at d 12, whereas MIF mRNA was detected in both undifferentiated and differentiated cells at relatively constant levels. Immunocytochemical analysis showed that MIF protein was present in preadipocytes and more pronounced in differentiated adipocytes. Freshly isolated mature adipocytes from sc, omental, and mammary depots released MIF at rates of up to 10,000 pg/ml.24 h. Most importantly, MIF production was positively correlated with donor body mass index. Secretion of MIF was not influenced by lipopolysaccharide, interferon-gamma, or IL-4. The rates of MIF release from sc and omental adipocytes were similar but approximately 10 times higher compared with mammary adipocytes.

CONCLUSIONS

Human preadipocytes and mature adipocytes from different depots spontaneously release substantial amounts of MIF. Expression levels were positively associated with donor body mass index. Hence, MIF may be an obesity-dependent mediator of macrophage infiltration of adipose tissue.

Identification of pancreatic exocrinopathy in non-obese diabetic mice by gene subtraction analysis

Type 1 diabetes is an immune-mediated disease with pancreatic infiltration and subsequent beta cell destruction. In this study pancreatic exocrinopathy in non-obese diabetic mice (NOD) was identified using gene subtraction methods (SSH) and macroarray analysis. Female NOD mice were treated with cyclophosphamide for acceleration and synchronization of the disease process at 70 d of age and analysed 10 d later, before the onset of overt diabetes. Extraction of total RNA of pancreas was followed by subtraction using the SSH technique. Pools of cDNA were generated using total RNA from treated and untreated NOD mice. Subtraction of cDNA pools of cyclophosphamide treated mice from cDNA pools of untreated mice resulted in a cDNA library, from which 480 clones were randomly selected. The clones were hybridized against labelled cDNA-probes generated from cyclophosphamide-treated and control NOD mice. Fifty-three clones (11 %) revealed at least twofold differential gene expression after cyclophosphamide treatment. Three of the downregulated genes (amylase, carboxypeptidase and preprotrypsin) were selected for evaluation of macroarray data by quantitative real-time PCR. Analysis of real-time PCR data confirmed suppression of gene expression with highest fold change for amylase (4.68-fold) followed by carboxypeptidase (2.79-fold) and preprotrypsin (2.14-fold). These results lead to the conclusion that inflammation in this animal model of type 1 diabetes is not restricted to pancreatic islets and that subtraction followed by macroarray analysis is capable of identifying genes responsible associated with disease progression.

Multiple Organ Failure due to 5-Fluorouracil Chemotherapy in a Patient with a Rare Dihydropyrimidine Dehydrogenase Gene Variant

BACKGROUND

Dihydropyrimidine dehydrogenase (DPD) is the initial and rate-limiting enzyme in the metabolism of the chemotherapeutic drug 5-fluorouracil (5-FU). Application of 5-FU is restricted by a narrow therapeutic index because of severe toxicity of WHO grades III-IV. The exon 14-skipping mutation (c.1905+1G>A) accounts for approximately a quarter of all severely toxic cases. However, numerous other polymorphisms have been identified within the DPYD gene in affected patients, and the pathophysiological significance of most of them is unclear.

PATIENT AND METHODS

We report a patient with advanced caecum cancer who twice received 950 mg 5-FU and 45 mg folinic acid as adjuvant by bolus injection. 2 days after onset of chemotherapy, the patient developed a multiple organ dysfunction exhibiting a cardiogenic shock with severe left ventricular insufficiency, marked reduction of renal function, and beginning hepatic encephalopathy with somnolence, myoclonus, and a seizure. In order to investigate a possible defect within the DPYD gene direct sequencing of all 23 exons was carried out.

RESULTS

Genotyping revealed a rare c.1601G>A polymorphism which causes a change in the protein sequence (S534N). Data regarding the clinical relevance are ambiguous. The polymorphism has been detected together with an intronic mutation and both polymorphisms have consistently been reported with reduced enzyme activity.

CONCLUSION

The present case provides further evidence of an etiologic role of the c.1601G>A mutation for DPD deficiency and the occurrence of severe 5-FU-related toxicity and underlines the value of comprehensive pharmakogenetic diagnostics with respect to the dihydropyrimidine dehydrogenase.

Wheat gluten causes dendritic cell maturation and chemokine secretion

Wheat gluten causes gut inflammation in genetically predisposed individuals. We tested the hypothesis that wheat gluten is not only a target of adaptive immunity, but also modulates the function of APC. Dendritic cells (DC) derived from the bone marrow of BALB/c mice were exposed to chymotrypsin-treated wheat gluten. This induced DC maturation as estimated by all surface markers tested (MHC class II, CD40, CD54, and CD86). The effect was dose dependent, and, at 100 microg/ml gluten matched that caused by 10 ng/ml LPS. A role of endotoxin contamination was ruled out by demonstrating the resistance of wheat gluten effects to LPS antagonist polymyxin B. DC from LPS nonresponder strain C3H/HeJ were affected by wheat gluten, but not by LPS. Proteinase K-digested wheat gluten was unable to stimulate DC maturation. Wheat gluten induced a unique secretion pattern of selected cytokines and chemokines in DC. Classic pro- or anti-inflammatory mediators were not produced, in contrast to LPS. Rather, chemokines MIP-2 and keratinocyte-derived cytokine were secreted in large amounts. We conclude that wheat gluten lowers the threshold for immune responses by causing maturation of APC, by attracting leukocytes and increasing their reactivity state. In the presence of an appropriate genetic predisposition, this is expected to increase the risk of adverse immune reactions to wheat gluten or to other Ags presented.

Prolonged stenting does not prevent obstruction after TIP repair when the glans was deeply incised

PURPOSE

To evaluate whether prolonged postoperative stenting may reduce the risk of obstruction of the neourethra after TIP repair with deep glanular incision.

METHODS

In a 1-year period 27 patients were operated for penile hypospadias using the TIP technique described by Snodgrass. In contrast to a previous study with 8 - 10 days of postoperative catheter drainage, the indwelling transurethral catheter was kept in place for 12 - 14 days. Deep incision of the urethral plate up to the tip of the glans is the most remarkable surgical detail, resulting in a meatus on top of the glans but in a defect on the dorsal rim of the neomeatus as well. After 3 - 6 months 22 patients were re-investigated during an outpatient visit using a scheme to describe the position of the neomeatus. Uroflowmetry was also performed. Information in three toddlers was gained by phone and 2 patients were lost to follow-up.

RESULTS

Two patients returned with significant obstruction including an urethrocutaneous fistula in one. In contrast to the good assessment by parents and compared to the early appearance after catheter removal a change in meatal position was observed in the majority of patients. Only 6 patients presented with an unchanged meatal position whereas in 16 patients the meatus lost its oval or slit-like shape as well as its position on the tip of the glans. However, despite one obstructive meatus in the coronal position 15 patients showed a sufficient size and position of the meatus underneath the tip of the glans. Uroflowmetry revealed reduced peak-flow values (mean: 8.1 ml/s) in some of the 9 patients evaluated.

CONCLUSIONS

Our data indicate that prolonged stenting does not give better results in those TIP repairs, in whom the urethral plate was incised across the rim of the neomeatus. The early excellent aspect of the glans after stent removal is often impaired by partial closure of the glans incision with a short-term change in size and position of the meatus. To prevent this, the rim of the meatus during reconstruction should be kept completely epithelialised.

Significant association of the interleukin-6 gene polymorphisms C-174G and A-598G with type 2 diabetes

Elevated blood concentrations of IL-6 have been shown to predict type 2 diabetes. Because the impact of IL-6 gene polymorphisms on diabetes status, parameters of the metabolic syndrome, and low-grade systemic inflammation has not been analyzed in a population-based study, we investigated the association of the IL-6 single nucleotide polymorphisms C-174G and A-598G on these parameters in 704 elderly participants of the Kooperative Gesundheitsforschung im Raum Augsburg/Cooperative Research in the Region of Augsburg (KORA) Survey 2000. Both -174G and -598G alleles were significantly associated with type 2 diabetes (-174G: odds ratio = 1.51, 95% confidence interval = 1.11-2.07, P = 0.0096; -598G: odds ratio = 1.56, 95% confidence interval = 1.13-2.15, P = 0.0069) but not with impaired glucose tolerance. In subgroup analyses, the association reached statistical significance in men and in leaner subjects (body mass index <or= 28.7 kg/m(2), i.e. study median) but not in women or more obese persons. Circulating IL-6 levels were not associated with the IL-6 polymorphisms, but significantly elevated levels of the chemokine monocyte chemoattractant protein-1/CC chemokine ligand 2 in carriers of the protective genotypes indicated an indirect effect of these single nucleotide polymorphisms on the innate immune system. Our findings confirm that immune gene polymorphisms can be considered as independent risk factors in the etiology of type 2 diabetes and suggest that their contribution may be indirect, by influencing the levels of other immune mediators like monocyte chemoattractant protein-1.

Evaluation of diagnostic relevance of mRNA levels in peripheral blood: predictive value for mortality in hemodialysis patients

In clinical practice, diagnosis and risk prediction are usually based on the analysis of serum or plasma proteins whereas gene expression analysis is not used on a routine basis. In order to compare the diagnostic and predictive relevance of serum protein and peripheral blood mRNA levels, we determined cytokine levels of end-stage renal failure patients undergoing hemodialysis. These patients face a high mortality mainly due to acceleration of atherosclerosis and subsequent severe vascular events. mRNA expression of the pro-inflammatory cytokine TNF alpha was significantly elevated in hemodialysis patients and further increased after 2 h of dialysis treatment. In contrast, gene expression of the anti-inflammatory cytokine TGF beta was significantly decreased. Patients who died during the observation period of 36 months had significantly increased mRNA levels of TNF alpha and decreased TGF beta mRNA expression at baseline. Survival analysis indicated that increased TNF alpha mRNA levels (P < 0.02) and TNF alpha/TGF beta mRNA ratios (P < 0.001) predict mortality. The corresponding cytokines in serum showed some association with disease, but serum concentrations neither changed during hemodialysis nor predicted mortality. This study shows that gene expression patterns of circulating leukocytes may present an important new diagnostic tool to predict clinical outcome in patients with inflammatory vascular diseases.

Identification of the heat shock protein 60 epitope involved in receptor binding on macrophages

In the present study, we identified the human heat shock protein 60 (HSP60) epitope responsible for binding to macrophages. Studies using overlapping 15- and 20-mer peptides of the human HSP60 sequence to compete with binding of HSP60 to macrophages indicated that surface binding was accounted for by the region aa481-500. Deletion mutants of HSP60, lacking the N-terminal 137, 243 or 359 amino acids, strongly inhibited HSP60 binding to macrophages. Monoclonal antibodies addressing regions aa1-200, aa335-366 or aa383-447 did not block HSP60 binding. We conclude that a single C-terminal region, aa481-500, accounts for the binding of HSP60 to macrophages.

IL-10 induces gene expression in macrophages: partial overlap with IL-5 but not with IL-4 induced genes

The hypothesis that IL-10, in addition to down-regulating pro-inflammatory activities of macrophages, induces an alternative state of macrophage reactivity was tested. We therefore conducted a systematic search for genes induced by IL-10 using the method of suppression subtractive hybridisation. Of an initial 1,300 candidate clones obtained, several screening rounds led to the identification of 51 clones which were reproducibly at least twofold up-regulated in mouse J774 macrophages in response to treatment with IL-10. Of these, 41 genes were homologous to known genes involved in cell metabolism or immunoregulation, five contained novel sequences and another five were homologous to ESTs without known function. One major finding was that about 25% of the IL-10 genes were also found expressed in response to IFNgamma, and several of these also reappeared in IL-4 or IL-5 induced mRNA species. Hence, Th1 and Th2 type cytokines may elicit a common basal activation response in macrophages. The second major finding was that 57% of IL-10 induced genes reappeared in IL-5 induced mRNA but no more than 18% were also found in IL-4 induced mRNA of J774 cells. We conclude that the gene expression response to IL-10 in macrophages is partially different from the response to IL-5 and is substantially different from the response to IL-4, which suggests an unexpected diversity of biological phenotypes induced by different Th2 type cytokines.

C-peptide is the appropriate outcome measure for type 1 diabetes clinical trials to preserve beta-cell function: report of an ADA workshop, 21-22 October 2001

The underlying cause of type 1 diabetes, loss of beta-cell function, has become the therapeutic target for a number of interventions in patients with type 1 diabetes. Even though insulin therapies continue to improve, it remains difficult to achieve normal glycemic control in type 1 diabetes, especially long term. The associated risks of hypoglycemia and end-organ diabetic complications remain. Retention of beta-cell function in patients with type 1 diabetes is known to result in improved glycemic control and reduced hypoglycemia, retinopathy, and nephropathy. To facilitate the development of therapies aimed at altering the type 1 diabetes disease process, an American Diabetes Association workshop was convened to identify appropriate efficacy outcome measures in type 1 diabetes clinical trials. The following consensus emerged: While measurements of immune responses to islet cells are important in elucidating pathogenesis, none of these measures have directly correlated with the decline in endogenous insulin secretion. HbA(1c) is a highly valuable clinical measure of glycemic control, but it is an insensitive measure of beta-cell function, particularly with the currently accepted standard of near-normal glycemic control. Rates of severe hypoglycemia and diabetic complications ultimately will be improved by therapies that are effective at preserving beta-cell function but as primary outcomes require inordinately large and protracted trials. Endogenous insulin secretion is assessed best by measurement of C-peptide, which is cosecreted with insulin in a one-to-one molar ratio but unlike insulin experiences little first pass clearance by the liver. Measurement of C-peptide under standardized conditions provides a sensitive, well accepted, and clinically validated assessment of beta-cell function. C-peptide measurement is the most suitable primary outcome for clinical trials of therapies aimed at preserving or improving endogenous insulin secretion in type 1 diabetes patients. Available data demonstrate that even relatively modest treatment effects on C-peptide will result in clinically meaningful benefits. The development of therapies for addressing this important unmet clinical need will be facilitated by trials that are carefully designed with beta-cell function as determined by C-peptide measurement as the primary efficacy outcome.

Combined activation of innate and T cell immunity for recognizing immunomodulatory properties of therapeutic agents

Complex syndromes such as atherosclerosis and type 2 diabetes are disorders that are associated with inflammatory processes involving innate and adaptive immunity. Emerging knowledge about the pathological consequences of immune imbalances in a wide range of disease settings is expected to help to identify novel therapeutic targets. However, current test systems for immunomodulatory drugs tend to be too simplistic, as they rely only on cells of the innate- or the adaptive-immune system, or they are complex, in vivo models, which are not suitable for screening purposes. Using a modified mixed lymphocyte culture (MMLC) assay for combined analysis of innate and adaptive immunity, we show that this assay is very sensitive for the presence of low concentrations of immunomodulatory agents. Low-dose lipopolysaccharide stimulation of cells from two unrelated donors yields a strong cytokine response including interleukin (IL)-12 and IL-18, which induce interferon-gamma as a potential analysis parameter. As the MMLC assay is based on the mutual interaction of cells of the innate and adaptive immunity, it enables the monitoring of cytokine release under almost physiological conditions and might be of interest for the characterization of known and novel drugs concerning their immunomodulatory potency.

C-peptide is the appropriate outcome measure for type 1 diabetes clinical trials to preserve beta-cell function: report of an ADA workshop, 21-22 October 2001

The underlying cause of type 1 diabetes, loss of beta-cell function, has become the therapeutic target for a number of interventions in patients with type 1 diabetes. Even though insulin therapies continue to improve, it remains difficult to achieve normal glycemic control in type 1 diabetes, especially long term. The associated risks of hypoglycemia and end-organ diabetic complications remain. Retention of beta-cell function in patients with type 1 diabetes is known to result in improved glycemic control and reduced hypoglycemia, retinopathy, and nephropathy. To facilitate the development of therapies aimed at altering the type 1 diabetes disease process, an American Diabetes Association workshop was convened to identify appropriate efficacy outcome measures in type 1 diabetes clinical trials. The following consensus emerged: While measurements of immune responses to islet cells are important in elucidating pathogenesis, none of these measures have directly correlated with the decline in endogenous insulin secretion. HbA(1c) is a highly valuable clinical measure of glycemic control, but it is an insensitive measure of beta-cell function, particularly with the currently accepted standard of near-normal glycemic control. Rates of severe hypoglycemia and diabetic complications ultimately will be improved by therapies that are effective at preserving beta-cell function but as primary outcomes require inordinately large and protracted trials. Endogenous insulin secretion is assessed best by measurement of C-peptide, which is cosecreted with insulin in a one-to-one molar ratio but unlike insulin experiences little first pass clearance by the liver. Measurement of C-peptide under standardized conditions provides a sensitive, well accepted, and clinically validated assessment of beta-cell function. C-peptide measurement is the most suitable primary outcome for clinical trials of therapies aimed at preserving or improving endogenous insulin secretion in type 1 diabetes patients. Available data demonstrate that even relatively modest treatment effects on C-peptide will result in clinically meaningful benefits. The development of therapies for addressing this important unmet clinical need will be facilitated by trials that are carefully designed with beta-cell function as determined by C-peptide measurement as the primary efficacy outcome.

Change in patients' body weight after 12 months of treatment with glimepiride or glibenclamide in Type 2 diabetes: a multicentre retrospective cohort study

AIMS/HYPOTHESIS

Our study compared the effects of glimepiride or glibenclamide treatment on body weight over 12 months of treatment in patients with Type 2 diabetes in routine outpatient practice.

METHODS

This new retrospective study design used data from physicians in a restricted manner (retrolective). Data from case report forms from 520 patients from 91 randomly selected centres were assessed and covariance analysis performed.

RESULTS

The influence of practice and patient characteristics on treatment assignment was low, reflecting the design of randomised controlled trials. Mean weight loss and reduction in body mass index from baseline to study endpoint were greater with glimepiride than with glibenclamide (-2.04+/-3.99 kg vs -0.58+/-3.65 kg, p<0.001; -0.71+/-1.38 kg/m(2) vs -0.20+/-1.28 kg/m(2), p<0.001). Duration of treatment at baseline influenced treatment outcome, but propensity score, sex, age and fasting blood glucose at baseline did not. Both glimepiride and glibenclamide led to decreases in fasting blood glucose (-2.43+/-0.24 mmol/l vs -3.03+/-0.24 mmol/l; p<0.001 vs baseline) and HbA(1c) (-1.23+/-0.09% vs -1.26+/-0.09%; p<0.001 vs baseline). Both treatments were associated with a decrease in serum total cholesterol and low density lipoprotein cholesterol. Triglycerides were lower in the glibenclamide group and high density lipoprotein cholesterol was higher in the glimepiride group only.

CONCLUSIONS/INTERPRETATION

Initial treatment of Type 2 diabetes with glimepiride was associated with a significantly greater decrease in body weight and body mass index than treatment with glibenclamide, while providing equivalent glycaemic control.

Diagnosis and classification of inguinal hernias

BACKGROUND

The aim of this prospective clinical study was to determine whether the presence of a hernia, its size, and its type can be established preoperatively by clinical and ultrasound, examination.

METHODS

The study population comprised 220 consecutive patients referred to our department for the surgical management of an inguinal hernia. On admission, both inguinal regions were examined clinically and by ultrasound. All patients were operated on laparoscopically.

RESULTS

In regard to the intraoperative findings for both inguinal regions, clinical and ultrasound examination for the diagnosis of inguinal hernia yielded a high total rate of accuracy of 93% respective 94%. However, when the same methods were used to differentiate between lateral and medial hernia, the total rate of accuracy fell to only 54% respective 62%. In the determination of inguinal hernia size, it was even lower: 50% respective 53%.

CONCLUSIONS

Although a diagnosis of inguinal hernia can be established reliably by clinical and ultrasound examination, only an approximate classification is possible by these methods.

[Pilot study of controlled retrospective analysis (retrolective study design) of care for type 2 diabetics since 1990]

BACKGROUND AND OBJECTIVE

There are few data on the quality of care received by patients with type 2 diabetes under routine conditions and only a few long-term studies that investigated the influence of treatment strategies on the development of clinical endpoints. It was the aim of this study, using retrospectively obtained data, to determine whether it is possible to document over a 10 year period the treatment design and clinical end-points in type 2 diabetics under the care of general practitioners.

PATIENTS AND METHODS

General practitioners were randomly selected and informed by independent collaborating monitors about the aim of the study and data documentation. At a second visit by a monitor the completed data forms were audited and entered into a database. Course of treatment was documented by 21 general practitioners, two of them diabetes specialists, for all patients in whom, between 1.1.1990 and 31.12.1993, type 2 diabetes had been diagnosed for the first time (n=455; 251 females, 204 males, mean age 61,5 years). Continuous complete documentation of the course of treatment in the given practice was obtained in 85% of patients over a mean observation period of 8,7 years. 45 myocardial infarcts in 40 patients (9%), 42 strokes in 37 patients (8%), blindness in seven eyes of five patients (1,5%) and 19 amputations (4,2%) were recorded; 72 patients died (15,8%).

CONCLUSION

The data of this pilot study indicate that detailed analysis of treatment quality can be obtained in a sizeable cohort, using of a well controlled retrospective (retrolective) study design.

An association of autoantibody status and serum cytokine levels in type 1 diabetes

At onset of type 1 diabetes, the islet autoantibody status of patients has been reported to predict progression of the disease. We therefore tested the hypothesis that the systemic immunoregulatory balance, as defined by levels of circulating cytokines and chemokines, is associated with islet autoantibody status. In 50 patients with recent-onset type 1 diabetes, antibodies to GAD and insulinoma-associated antigen 2 (IA-2) were analyzed by radioimmunoassay; cytoplasmic islet cell antibodies were determined by indirect immunofluorescence. Cytokine and chemokine concentrations were measured by rigidly evaluated double antibody enzyme-linked immunosorbent assay. Of four classically defined Th1/Th2 cytokines (gamma-interferon, interleukin [IL]-5, IL-10, IL-13), none showed an association with multiple autoantibody positivity. Of six mediators mainly produced by innate immunity cells, three were associated with multiple autoantibody status (IL-18 increased, MIF and MCP-1 decreased) and three were unaffected (IL-12, MIP-1beta, IP-10). GAD and/or IA-2 antibody titers negatively correlated with systemic concentrations of MIF, MIP-1beta, and IL-12. Combining the data of several cytokine and chemokine levels made it possible to predict islet antibody positivity in individual patients with 85% sensitivity and 94% specificity. These data suggest a close association of islet antibody status with systemic immunoregulation in type 1 diabetes.

Human heat shock protein 60 induces maturation of dendritic cells versus a Th1-promoting phenotype

Heat shock protein (HSP) 60 nonspecifically activates cells of the innate immune system. In the present study, we characterized the effects of human HSP60 maturation, cytokine release, and T cell-activating capacity of bone marrow-derived dendritic cells (DC). Furthermore, we analyzed HSP60-induced signal transduction in DC. HSP60 strongly stimulated DC for maturation and release of TNF-alpha, IL-12, and IL-1 beta. However, HSP60 elicited only a weak IL-10 response in DC suggesting a Th1 bias. HSP60-treated DC induced proliferation of allogeneic T cells. Again, a Th1 bias was noted in that cocultures of allogeneic T cells and HSP60-treated DC released IFN-gamma but only small amounts of IL-10 and no detectable IL-4. Signaling via Toll-like receptor 4 was involved in HSP60-induced cytokine release and maturation because DC of C3H/HeJ mice with a mutant Toll-like receptor 4 showed deficient response to HSP60. HSP60 was found to rapidly activate the mitogen-activated protein kinases p38, c-Jun N-terminal kinase, and extracellular signal-regulated kinase as well as I kappa B in DC. Phosphorylation of these signaling molecules was also mediated by LPS, but with much slower kinetics. Thus, HSP60 stimulates DC more rapidly than LPS and elicits a Th1-promoting phenotype. These results suggest that DC play a pivotal role in priming for destructive Th1-type responses at sites of local HSP60 release.