Transmission of ESBL/AmpC-producing Escherichia coli from broiler chicken farms to surrounding areas.

Although previous studies have demonstrated high carriage of ESBL/AmpC-producing Escherichia coli in livestock, especially in broiler chickens, data on emission sources of these bacteria into the environment are still rare. Therefore, this study was designed to systematically investigate the occurrence of ESBL/AmpC-producing E. coli in slurry, air (inside animal houses), ambient air (outside animal houses) and on soil surfaces in the areas surrounding of seven ESBL/AmpC-positive broiler chicken fattening farms, including investigation of the possible spread of these bacteria via the faecal route and/or exhaust air into the environment. Seven German broiler fattening farms were each investigated at three points in time (3-36 h after restocking, 14-18 and 26-35 days after housing) during one fattening period. The occurrence of ESBL/AmpC genes in the investigated samples was confirmed by PCR, detecting blaCTX-M, blaSHV, blaTEM and blaCMY-genes, and, if necessary, by sequencing and/or the disc diffusion method. The results showed a wide spread of ESBL/AmpC-producing E. coli in broiler farms, as well as emissions into the surroundings. 12 out of 14 (86%) slurry samples were positive for ESBL/AmpC-producing E. coli. Additionally, 28.8% (n=23/80) of boot swabs taken from various surfaces in the areas surrounding of the farms as well as 7.5% (n=3/40) of the exhaust air samples turned out to be positive for these microorganisms. Moreover, a small proportion of air samples from inside the barns were ESBL/AmpC-positive. By comparing selected isolates using pulsed field gel electrophoresis, we proved that faecal and airborne transfer of ESBL/AmpC-producing microorganisms from broiler fattening farms to the surrounding areas is possible. Two isolates from farm G2 (slurry and boot swab 50 m downwind), two isolates from farm G3 (slurry and individual animal swab) as well as two isolates from farm G6 (air sample in the barn and air sample 50 m downwind) showed 100% similarity in PFGE analysis.

Longitudinal monitoring of extended-spectrum-beta-lactamase/AmpC-producing Escherichia coli at German broiler chicken fattening farms.

Antimicrobial resistance of Escherichia coli to modern beta-lactam antibiotics due to the production of extended-spectrum beta-lactamases (ESBL) and/or plasmid-mediated AmpC beta-lactamases (AmpC) represents an emerging and increasing resistance problem that dramatically limits therapeutic options in both human and veterinary medicine. The presence of ESBL/AmpC genes in commensal E. coli from food-producing animals like broilers may pose a human health hazard. However, there are no data available concerning the prevalence of ESBL/AmpC-producing E. coli in German broiler flocks using selective methods. In this longitudinal study, samples were taken from seven conventional broiler fattening farms at three different times within one fattening period. Various samples originating from the animals as well as from their direct environment in the barn were investigated for the occurrence of ESBL/AmpC-producing E. coli. Average detection levels of 51, 75, and 76% in animal samples collected during the three samplings in the course of the fattening period demonstrate a colonization of even 1-day-old chicks, as well as a continuous significant (P < 0.001) increase in prevalence thereafter. The detection frequencies in housing environmental samples were relatively high, with an increase over time, and ranged between 54.2 and 100%. A total of 359 E. coli isolates were characterized by PCR and partly via the disc diffusion method. This study shows that prevalence of ESBL/AmpC-producing E. coli increases during the fattening period of the broiler flocks examined. Both colonized day-old chicks and contaminated farm environments could represent significant sources of ESBL/AmpC-producing E. coli in German broiler fattening farms.

A reliable test to detect impending pump failure during long-term support on the Novacor N100 Left Ventricular Assist System.

The Durastudy is a new surveillance protocol to detect impending pump failure in Novacor N100 Left Ventricular Assist Systems implanted for the long term. Our patient, a 54-year-old man with a history of dilated cardiomyopathy and contraindications for heart transplantation, received a Novacor pump in May 1995 and did not experience sustainable ventricular recovery during the subsequent 3 years. After more than 3 years of support, symptoms of pump wear were detected in this patient, through application of the Durastudy protocol. This enabled us to electively exchange the pump at 3.8 years. Our patient remained in New York Heart Association functional class I until he died in July 1999 of causes unrelated to the pump, after some 1,514 days of support. This, we believe, still constitutes a world record.

A new semi-automatic endothelial cell seeding technique for biological prosthetic heart valves.

BACKGROUND: Until today, tissue heart valve prostheses have been made with biological dead porcine or bovine tissue. However, the durability of this tissue is limited due to degeneration and calcification. Surface seeding with vital human endothelial cells (EC) could improve valve durability and bio-compatibility. A new seeding technique that includes a newly developed special seeding device is presented here. METHODS: The aortic valve, including a cylinder of the aortic root, was prepared from a fresh porcine heart taken from the slaughterhouse. Porcine endothelial cells were removed by surface treatment with chemical detergent solutions. A new seeding device with an integrated CO2-incubator was designed. The device is composed of: the seeding chamber (SC), the rotation unit (RU), and the Control Unit (CU). The porcine aortic root cylinder with the valve leaflets is placed into the SC. A matrix of fibronectin is applied to the acellular valve. The SC is then filled with the endothelial cells suspended in modified Dulbecco's eagle medium (DMEM). Under cell culture conditions, the endothelial cell seeding of the tissue valve is established by rotating the valve around two orthogonal axes simultaneously and independently. This is done following the software controlled preset parameters. RESULTS: Using initial endothelial cell seeding concentrations of 6x10(6) endothelial cells/ml DMEM, it was possible to achieve a seeding efficiency of 80-85% within 3-4 hrs. Cell viability tests proved that 90-95% of the seeded endothelial cells are vital after the seeding procedure. CONCLUSIONS: This new seeding technique allows the complex warped surface of a tissue heart valve to be covered with vital endothelial cells to form a confluent endothelial cell monolayer.

Diagnosis and management of left ventricular assist device valve-endocarditis: LVAD valve replacement.

A 57-year-old man who has been wearing a Novacor N100 left ventricular assist device (LVAD) for more than 3 years suffered from LVAD endocarditis. Only by immunoscintigraphic methods was it possible to localize the septic focus. After successful exchange of in- and outflow tract valves, the infection was eradicated. Microscopic investigation confirmed the scintigraphic findings: Gram-positive bacteria were found. The valves showed no gross degenerative lesions after more than 1,100 days of implantation. The patient is now doing well.

Clinical experience with autologous endothelial cell-seeded polytetrafluoroethylene coronary artery bypass grafts.

OBJECTIVE: Autologous endothelial cell seeding was used to improve the patency of 4-mm polytetrafluoroethylene vascular prostheses. METHODS: Since 1995, 14 patients with coronary artery disease received 21 autologous endothelial cell-seeded polytetrafluoroethylene vascular bypass grafts for coronary artery revascularization. The polytetrafluoroethylene grafts were seeded with the endothelial cells in a multiple step procedure, including cell culture techniques before coronary bypass operation. With the use of extracorporal circulation and cardioplegic arrest, a bypass operation was performed by means of conventional surgical techniques. RESULTS: After a mean postoperative follow-up of 27.7 months (range, 7.5-48 months), the graft patency rate is 90.5%. Follow-up angiograms of the aorta-coronary polytetrafluoroethylene bypass grafts showed patent bypasses in all cases except two. Angiograms of all 19 patent endothelial cell-seeded polytetrafluoroethylene bypass grafts showed a smooth luminal borderline without stenotic regions. The percutaneous transluminal angioscopic evaluation showed a glossy white and smooth endoluminal graft surface without any fibrin, platelet, or erythrocyte deposits. Intravascular ultrasonographic examinations confirmed the results. CONCLUSION: Patency of autologous endothelial cell-seeded 4-mm polytetrafluoroethylene vascular prostheses as coronary artery bypass grafts was much better than that of unseeded polytetrafluoroethylene grafts. Further evaluations and a larger population of patients will prove whether the encouraging patency will last.

Recovery from end-stage ischemic cardiomyopathy during long-term LVAD support.

A patient with ischemic cardiomyopathy and extremely reduced left ventricular function (left ventricular ejection fraction=0.10) presented to our institution for cardiac transplantation. Because of his worsening condition he was placed on the Novacor left ventricular assist device. During 3 months of support his left ventricular function recovered and he successfully underwent percutaneous transluminal coronary angioplasty and minimally invasive direct coronary artery bypass grafting procedures; subsequently he could be weaned from the left ventricular assist device and discharged. The patient is no longer considered for cardiac transplantation.

The effect of acarbose on insulin sensitivity and proinsulin in overweight subjects with impaired glucose tolerance.

Insulin sensitivity is impaired in overweight subjects with IGT and is accompanied by hyperinsulinemia, a condition, that might promote early B-cell exhaustion. Twelve subjects were recruited for a double-blind trial using either 100 mg of acarbose or placebo for three months. Insulin sensitivity was measured by hyperglycemic clamp and with the minimal model. Baseline characteristics such as body weight, BMI, blood glucose, HB-A1c and serum lipids did not change throughout the study period. The steady state glucose infusion rate (SSGIR) improved significantly following acarbose. The insulin sensitivity as measured by clamp (MI) or minimal model, (SI), however, increased only descriptively (p = 0.08). The fasting proinsulin was raised in all subjects during pretreatment. Following acarbose, the proinsulin dropped from 20.3 +/- 12.9 to 13.6 +/- 7.1 ng/ml, but remained unchanged in the placebo group. Due to the high variability of values and the low number of subjects in this study, differences were only descriptive and did not reach significance (p = 0.08). The proinsulin/insulin ratio, however, significantly decreased after 3 months of acarbose treatment. Acarbose might therefore be considered recommendable for the protection of the B-cell function and for delaying the transition of IGT to overt NIDDM.

Intensive therapy in adult insulin-dependent diabetes mellitus is associated with improved insulin sensitivity and reserve: a randomized, controlled, prospective study over 5 years in newly diagnosed patients.

Optimal blood glucose levels and normal insulin sensitivity are aims in the treatment of insulin-dependent diabetes mellitus (IDDM). Insulin sensitivity and insulin reserve are closely interrelated. It is essential to know more about both of these parameters at clinical diagnosis, because their preservation may delay the occurrence of diabetes-related complications. B-cell function is likely to be retained for a longer period in patients with adult onset of the disease compared with children. In this study, intensive insulin treatment was initiated in newly diagnosed adult patients to determine if it preserved endogenous insulin secretion longer than conventional therapy. Forty-nine patients with newly diagnosed diabetes were carefully categorized as having IDDM according to clinical and serological criteria. They were randomized to an intensive (I group) or conventional (C group) insulin therapy and evaluated for 5 years. Every 6 months, a check-up included glucagon-stimulated C-peptide (GSCP), hyperglycemic glucose clamp with arginine bolus, euglycemic-hyperinsulinemic clamp, and screening for microalbuminuria, retinopathy, and neuropathy. At the end of the study, hemoglobin A1c (HbA1c) was 6.3% +/- 1.9% in the I patients and 8.1% +/- 2.1% in the C patients (P < .001). Blood glucose concentrations less than 3.5 mmol/L were more frequent in the I group than in the C group (P < .05). Insulin sensitivity (M/I) and GSCP were higher in intensively treated patients after 5 years (M/I, I group 40 +/- 10 nmol x kg(-1) x min(-1) x pmol/L1 v C group 21 +/- 11, P < .005; GSCP, I group 0.6 +/- 0.2 nmol/L v C group 0.19 +/- 0.11, P < .005). The prevalence of peripheral neuropathy was significantly lower in the I group at the end of the study. In conclusion, intensive therapy is more effective in the preservation of insulin action and reserve. In our patients, no case of severe hypoglycemia was observed, indicating that intensive therapy was safe in these patients.

Effect of dietary protein intake on insulin secretion and glucose metabolism in insulin-dependent diabetes mellitus.

Adult-onset insulin dependent diabetes mellitus (IDDM) is associated with significant residual insulin secretion. The process leading to the ultimate destruction of B cells may be influenced, among other factors, by the quality and amount of ingested protein. Using a standardized food questionnaire, we matched 13 individuals with normal protein (NP; 0.74 +/- 0.08 g/kg.day) and high protein (HP; 1.87 +/- 0.26 g/kg.day) intake from a sample of 117 newly diagnosed IDDM patients according to sex, age, body mass index, and energy intake. Nondiabetic control subjects were also selected. Dietary habits did not change significantly over an observation period of 1 yr. Glucagon-stimulated C peptide was significantly higher in the NP compared to the HP group (0.71 +/- 0.06 vs. 0.50 +/- 0.04 nmol/L; P < 0.002). NP food was associated with higher overall insulin sensitivity in both patients and nondiabetic subjects. Hepatic glucose output was significantly increased in individuals with HP intake [HP IDDM, 14.8 +/- 0.6 vs. NP IDDM, 12.7 +/- 0.7 (P < 0.01); HP control, 12.2 +/- 0.5 vs. NP control, 10.9 +/- 0.5 (P < 0.01 mumol/kg.min). Insulin-mediated suppression of hepatic glucose production was impaired in diabetic patients with high protein intake, but not in patients with normal protein diet. Gluconeogenesis estimated from 13C enrichment in breath and plasma was increased in individuals on a HP diet. We conclude that a NP diet is accompanied by delayed progression of the continuous loss of endogenous insulin in IDDM. This phenomenon is possibly due to decreased insulin demand on the B cells and/or reduced hepatic glucose production favoring enhanced insulin sensitivity.

A diet enriched in protein accelerates diabetes manifestation in NOD mice.

Diet modifies the development of insulin-dependent diabetes mellitus in animals and in humans. We examined female non-obese-diabetic (NOD) mice, a diabetes-prone mouse strain with 70% spontaneous diabetes incidence and metabolic abnormalities in non-overtly diabetic litters. They were fed a diet containing 55% (n = 27) or 15% (n = 26) protein, respectively, after weaning. At an age of 30 weeks, non-diabetic NOD mice were submitted to an intravenous glucose tolerance test (0.5 g/kg body weight; blood samples were taken after 2, 4, 8, 10, 15, 20 and 30 min) and to perfusion of the pancreas (stimulation media were Krebs-Ringer-Hepes buffer with 5 mmol/l glucose, 30 mmol/l glucose and 5 mmol/l glucose plus 19 mmol/l arginine). Diabetic mice were removed from the experiment. Serum glucose concentration and body weight were monitored weekly. Food ingestion was checked at an age of 11 weeks. On average, the onset of diabetes was diagnosed in mice on a high-protein diet (19.7 +/- 1.3 weeks) 4 weeks earlier than in mice on a low-protein diet (23.5 +/- 1.1 weeks; P < 0.05). Non-diabetic NOD mice on a high-protein diet showed significantly better glucose tolerance (as determined by the glucose disappearance rate) and mean insulin secretion (at 30 mmol/l glucose). No difference in the serum glucose concentration between non-diabetic mice on the low-protein diet or high-protein diet could be proved. In non-diabetic mice on the high-protein diet the body weight and food ingestion exceeded those of mice on the low-protein diet (P < 0.05). High insulin secretion and glucose tolerance in non-diabetic mice may reflect the capacity of beta-cells to adapt; however, beta-cells tend to be destroyed under such circumstances. Thus, a high-protein diet promoted the onset of diabetes, but it did not increase significantly the incidence of the disease.

[Endoventricular patch-plasty for reconstruction of ventricular geometry and pump function in myocardial aneurysm]. / Endoventrikuläre Patchplastik zur Wiederherstellung von Ventrikelgeometrie und Pumpfunktion beim Herzwandaneurysma.

This report deals with the first experience with endoventricular patch plasty in patients suffering from left ventricular aneurysm. The early postoperative results in 18 patients operated upon during January and May 1995 are encouraging. All patients survived the procedure. In contrast to patients operated on according to a linear resection technique the postoperative outcome and the early results are much better with this technique. We recommend the endoventricular patch plasty on a beating heart.

[Acute and chronic mechanical circulatory support]. / Akute und chronische mechanische Kreislaufassistenz.

Mechanical circulatory support and mechanical unloading of the left ventricle become more and more routine in clinical treatment regimens of both acute and chronic heart failure. Along with increasing availability of different cardiac assist systems one can adjust the degree of support according to the clinical situation. We report about our experience in the period between January 1994 and May 1995 with following assist systems: Hemopump, centrifugal pumps, Medos, HIAVAD and Novacor. We implanted those devices in 21 patients out of following indications: postinfarct--cardiac failure (CF), postcardiotomy CF, elective postcardiotomy support, myocarditis CF and "bridge" to transplant. Ten patients survived the period of mechanical support and could be weaned successfully. Circulatory support was sufficient in all cases, indication, time of implantation, anticoagulation and prevention of infections are discussed.

Clinical spectrum of the MELAS mutation in a large pedigree.

INTRODUCTION: MELAS is most often due to an mentally transmitted A-G transition mutation of mitochondrial DNA (mtDNA) at position 3243. In this study we report on the clinical spectrum associated with the mutation in the largest family reported so far. PATIENTS AND METHODS: In a family with three MELAS cases we identified 47 persons at risk for the mutation; sufficient data was available on 29. Mitochondrial disease was diagnosed in two of 9 deceased numbers (posthumous molecular analysis in one); 27 surviving family members underwent examination and 25 a molecular analysis of mt DNA from lymphoblasts. Then had a muscle biopsy and two were later autopsied. RESULTS: All 26 cases investigated by molecular analysis showed the mutation at position 3243. The 18 symptomatic patients without stroke-like episodes had sensorineural hearing loss in 15 cases, diabetes in 6, nephropathy in 7, mild myopathy in 4, cardiomyopathy in 2, cerebellar disease in 4 and mental retardation in 2 cases. Eight carriers were asymptomatic. Autopsy showed > 80% mutant mt DNA in all tissues except blood (20%) examined in a MELAS patients, but < 20 mutant mt DNA in all tissues except lever (40%) and kidney (70%) in a patient with hepatopathy, renal failure and diabetes. Histologic and biochemical studies of muscle biopsy were often non-informative. CONCLUSIONS: The mutation of mt DNA at position 3243 causes a multisystem disorder with a variable phenotype due to heteroplasmy. Most carriers are oligosymptomatic with hearing loss and a variety of neurological and internal medical symptoms. Diabetes, cardiomyopathy and renal disease, which is newly reported here for this mutation, are frequent. The blood test is a reliable screening tool in affected families, but is of prognostic value only combined with examination of other tissues.

Natural course of insulin sensitivity and insulin reserve in early insulin-dependent diabetes mellitus.

Preservation of endogenous insulin in insulin-dependent diabetes mellitus (IDDM) may prevent the occurrence of diabetes-related complications. Therefore, it is important to known about insulin reserve and insulin sensitivity at clinical manifestation. Twenty-four patients (aged 23 +/- 6 years) were evaluated for 2 years starting at the day of clinical manifestation. Insulin secretion was stimulated by glucagon, arginine, and glucose on separate days. Insulin sensitivity was evaluated by hyperinsulinemic-euglycemic clamp. Two control groups were established, one consisting of age-, weight-, and sex-matched healthy individuals, the other of patients with diabetes of long duration (6 to 13 years). Sensitivity improved from 30% of normal at baseline to 84% after only 2 weeks in the newly manifested patients. Subsequently, insulin released by nonglucose stimuli increased by 75%. Glucose-induced first-phase insulin secretion did not recover. After 2 years, sensitivity was 20% less than normal and glucagon-stimulated C-peptide (GSCP) was 0.64 +/- 0.20 nmol/L (0.41 +/- 0.19 at baseline, P < .002). Insulin sensitivities in euglycemic and hyperglycemic conditions were closely correlated. In conclusion, improvement of insulin sensitivity precedes and is possibly a prerequisite for the recovery of residual insulin in early IDDM.

[Glomus tumors: a diagnostic and surgical challenge?]. / Glomustumoren: eine diagnostische und chirurgische Herausforderung?

Within a population of 1150 vascular patients over a time period of 10 years we saw a carotid body tumor (synonymous chemodectoma) in only 11 cases. A correct preoperative diagnosis was found only in three patients. Before being treated by a specially trained team of vascular surgeons, eight patients had undergone inadequate operations. These were performed with a high incident of local complications. Simple bedside physical examination of the patient while looking for the signs of Fontaine and Kocher I + II (20) assures the diagnosis. Confirmation can be achieved by color-flow Doppler sonography (2). For the surgical resection, the only therapeutic alternative to the "gold standard" is angiography in digital subtraction technique which illustrates the blood supply of the tumor (70% exclusively by the external carotid artery). Also, it shows the typical intercarotid widening and the rich vascular conglomerate in between. Malignancy was detected in one case only (pulmonary metastasis). In two cases concomitant tumors of the jugular vein were seen. The interruption of the blood flow in the external carotid artery facilitates the surgical approach substantially. The ligature of this vessel (six patients) and the interposition of saphenous vein grafts (all 11 cases) for reconstruction of the internal carotid vessel were employed as the surgical strategy. Even the exstirpation of a large tumor (18 x 11 x 9 cm) extending from the skull base and almost reaching the left clavicular bone was successfully performed.(ABSTRACT TRUNCATED AT 250 WORDS)