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Biomedical subjects

U Kuhlmann

Publications and source records attributed to U Kuhlmann.

At least 19 recordsLinked to original sources
PubMed2003

Basic biology and small-scale rearing of Celatoria compressa(Diptera: Tachinidae), a parasitoid of Diabrotica virgifera virgifera (Coleoptera: Chrysomelidae).

The tachinid Celatoria compressa Wulp has been evaluated as a candidate biological control agent for the western corn rootworm, Diabrotica virgifera virgiferaLeConte, in Europe, where it is an invasive alien pest of maize. Special emphasis has been placed on understanding aspects of the parasitoid basic biology and on developing a rearing technique for a small-scale production of C. compressapuparia. The age of C. compressa adults was found to be the most crucial factor in achieving mating. Only newly emerged, 1-h-old females, mated successfully with 2- to 5-day-old males, achieving a success rate of 74%. After mating, a prelarviposition period of 4 days occurred. The 5-day-old C. compressa females inserted their eggs containing fully-developed first instars directly into adults of D. v. virgifera. Total larval and pupal developmental time, including a pre-larviposition period of 4 days, was 29 days under quarantine laboratory conditions (25 degrees C daytime, 15 degrees C at night, L:D 14:10, 50% +/- 10% r.h). Females of C. compressa were capable of producing on average 30 puparia throughout a female's mean larviposition period of 15 days. A large number of host attacks by C. compressa were unsuccessful, resulting in a mean larviposition success rate of 24% per female. Parasitoid females appear to have difficulties inserting the egg through the intersegmental sutures or membranes around leg openings of the host adults. Although the small-scale rearing technique of C. compressa presented is both time and labour intensive, C. compressa has been reared successfully for at least 20 successive generations without shifting the 1 male : 1 female sex ratio using a non-diapause strain of D. v. virgifera.

Age Factors↗
PubMed2001

Accuracy and safety of online clearance monitoring based on conductivity variation.

BACKGROUND: Haemodialysis dose has been shown to have a distinct impact upon the morbidity and mortality rate in patients on regular dialysis therapy. Accordingly, the adequacy of dialysis treatment should be guaranteed. METHODS: In 200 dialysis sessions two or three +/-10% dialysate conductivity variations were applied to test patient compliance and the accuracy of an electrolyte based online clearance measurement (OCM) reflecting the total clearance of urea. RESULTS: Using a step profile the electrolytic clearance showed highly significant correlation with the reference data in the blood side (n=118, r=0.867, P<0.001) and dialysate side (n=118, r=0.820, P<0.001) if only reference values were taken into account for which the error in mass balance did not exceed 5%. Kt/V according to the single pool model (n=35, r=0.940, P<0.001), the equilibrated single pool variable volume kinetic model (n=36, r=0.982, P<0.001), Daugirdas formula (n=34, r=0.951, P<0.001) and direct quantification of dialysance via spent dialysate (n=26, r=0.900, P<0.001) showed outstanding correlations with electrolyte-based Kt/V at mass balance error below 5%. No adverse clinical effect of OCM was reported. Serum sodium, body weight, heart rate and breathing rate at rest, arterial pO(2) and pCO(2) and blood pressure before haemodialysis remained unaffected in OCM measurements in comparison with baseline parameters. A small influx of sodium (1.53+/-7.62 mmol) into the patient was seen following the impulse, but no signs associated with fluid overload were observed during the study period of 10 consecutive dialysis sessions. CONCLUSIONS: The OCM option of the haemodialysis machine provides a safe and accurate tool for continuous online monitoring of total urea clearance.

Adult↗
PubMed2001

Sustaining continuous ambulatory peritoneal dialysis after herniotomy.

Controversy still exists as to whether peritoneal dialysis (PD) treatment can be safely continued after herniotomy. Many nephrologists withhold PD treatment for several weeks after herniotomy for fear of dialysate leakage and hernia recurrence. Here, we report on 9 patients (2 women, 7 men) in whom herniotomy was performed for umbilical (n = 3), inguinal (n = 5), or cicatricial hernia (n = 2), or for open processus vaginalis (n = 2). Surgery was performed according to the Lichtenstein method with insertion of a polypropylene mesh and ligation of the hernia sac. In all patients, PD treatment was paused for the day of surgery and for 1-3 days postoperatively, depending on residual renal function. Over the next several days, low-volume (1.0-1.5 L), high-frequency (6 per day) exchanges were started. The patient's original PD regimen was gradually reinstated over the next 2-4 weeks. All patients recovered rapidly, with no uremia or dialysis-related complications. Particularly, no leakage and no hernia recurrence could be observed 3 months thereafter. None of the patients had to be hemodialyzed intercurrently. In conclusion, continuing a modified regimen of CAPD treatment after herniotomy seems to be safe, with excellent patient comfort.

Adult↗
PubMed2001

Resting metabolic rate in chronic renal failure.

OBJECTIVE: A decrease in resting metabolic rate (RMR) in patients with chronic renal failure was assumed to occur because of the decreasing oxygen consumption of the kidneys, which in healthy subjects, accounts for 7.2% of RMR. Contrary to this assumption, RMR per body weight in end-stage renal disease was increased. DESIGN AND METHODS: To test the impact of chronic renal failure on the RMR, direct bedside calorimetry was performed on 51 outpatients (age, 53.2 +/- 13.9 y; creatinine clearance, 6.9 to 52 mL/min). Twenty two of 51 patients were examined repeatedly (at the start of the study, after 3 months, and after 6 months) during declining kidney function. RESULTS: In the total group, RMR per body weight (RMR/BW) was 100.0 +/- 4.96 kJ/kg/day and RMR per body surface area (RMR/BSA) was 4.582 +/- 0.181 kJ/min/1.73m(2). RMR/BW and RMR/BSA correlated significantly with creatinine clearance (n = 51, r = -.763, P <.001; n = 51, r = -.557, P <.001). In the follow-up group, creatinine clearance decreased from 27.5 +/- 9.5 mL/min initially, to 19.4 +/- 6.25 mL/min at 3 months, to 13.0 +/- 3.8 mL/min at 6 months (P <.001), while RMR/BW and RMR/BSA increased from 98.28 +/- 6.3, to 101.64 +/- 5.46, to 105.42 +/- 6.3 kJ/kg BW/d (P <.005), respectively, and 4.41 +/- 0.126, to 4.578 +/- 0.168, to 4.704 +/- 0.168 kJ/min/1.73 m(2) (P <.05), respectively. CONCLUSION: Taking into account the reduced oxygen consumption of the shrinking kidneys, the normal RMR suggests an increased energy expenditure per body cell mass. The raising RMR in deteriorating excretory kidney function reflects the increasing energy expenditure in progressive chronic renal failure.

Basal Metabolism↗
PubMed2000

Stimulated IFNgamma and IL-10 secretion of blood mononuclear cells in patients on renal replacement therapies show different secretion patterns.

Infection is still a leading cause of morbidity and mortality in patients on renal replacement therapy (RRT). Although the role of the immune system is of great importance, little is known about the influence of the mode of RRT to the preferential excretions of regulator cytokines of mononuclear cells. Therefore, we investigated the stimulated IFNgamma (Th1) and IL-10 (Th2) secretions of mononuclear cells from patients on RRT. Blood was drawn from 10 controls, 15 patients on hemodialysis (HD), 15 on peritoneal dialysis (PD), and 10 after kidney transplantation (Tx). The cells were separated, and phytohemagglutinine (PHA) was added for stimulation. After 0, 6, and 24 h, IFNgamma and IL-10 (pg/ml) were measured by enzyme-linked immunosorbent assay. IFNgamma secretion was significantly enhanced 6 (p < 0.001) and 24 h (p = 0.002) after stimulation in all groups (in mean +/- SEM). The analysis of the subgroups 6 h after adding PHA showed significant differences (p = 0.0239) with the lowest IFNgamma in Tx (16 +/- 5) and the highest in PD (79 +/- 30). For IL-10, secretion was enhanced in all groups 6 h after stimulation (p < 0.0116). The lowest secretions were seen in HD (18 +/- 8) and controls (27 +/- 9); the highest secretions were in Tx (98 +/- 20) and PD (57 +/- 12). The differences between HD and Tx (p < 0.01) and HD versus PD (p = 0.05) were significant. The stimulated cytokine secretion of blood mononuclear cells is preserved with RRT. The modes of RRT could influence the pattern of cytokine secretion. Surprisingly, the cells from patients on PD showed enhanced IL-10 secretion compared to HD. Presumably, this is due to the chronic contact of peritoneal dialysis fluids with monocytes and the lymphatic system in PD.

Adult↗
PubMed2000

A new lactate-based, plasticizer-free, neutral peritoneal dialysis fluid provided in a two-compartment system: effect on peripheral leukocyte function.

BACKGROUND: A new neutral peritoneal dialysis fluid (PDF; Balance) provided in a two-compartment bag (pH 7.4, no plasticizers, minimal glucose degradation products - GDP) was investigated in comparison with a neutral control (Hanks' balanced salt solution with gelatin 0.1%) and other PDFs with standard properties and plasticizers (Andy plus, pH 5.2, GDP), plasticizer free (stay safe, pH 5.2, GDP), and in addition plasticizer free after sterile filtration instead of heat sterilization (pH 5.2) regarding the function of peripheral blood leukocytes. METHODS: Blood was drawn from 12 volunteers, and blood monocytes (MN) and polymorphonuclear leukocytes (PMNL) were collected. The cells were incubated for 30 min in control medium and the PDFs: glucose 1.5% (83 mmol/l) and 4.25% (238 mmol/l). Respiratory burst of cells was evaluated by chemiluminescence and superoxide (SO) generation after stimulation with phorbol myristate acetate. RESULTS: In comparison with the control medium, incubation of MN in the two-compartment PDF showed preservation of respiratory burst. In contrast, the incubation of MN in standard PDF and plasticizer-free PDF showed impaired functions. The same was found for PMNL. SO anion measurement in MN and PMNL after incubation in the new two-compartment PDF also showed preservation of cell function in comparison with the control medium. The incubation of PMNL in standard PDF and plasticizer-free PDF with a high glucose content showed depressed SO anion generation. CONCLUSIONS: These in vitro data demonstrate a better preservation of in vitro phagocyte function with adaptation of pH and reduction of glucose, GDP, and plasticizers in PDFs. The best results are achieved with the two-compartment, lactate-based neutral PDF.

Adult↗
PubMed2000

Plasmapheresis in life-threatening verapamil intoxication.

Verapamil intoxications are life-threatening conditions with a far too often fatal outcome. In 2 patients, severe suicidal intoxication by 2.4 g and 9.6 g of verapamil orally resulted in life threatening hypotension and bradycardia with the need of heart-pacing and resuscitation. Plasmapheresis was started within less then 4 hours after intoxication and seemed to reduce the verapamil plasma concentration to less then 40%. A dramatic improvement of cardiovascular stability was already observed during plasmapheresis. In-vitro plasmapheresis was performed to verify the effectiveness of the extracorporeal detoxification. Verapamil was removed out of the blood by a clearance of 29.2 ml/min at blood flow of 200 ml/min. In conclusion, severe verapamil poisoning should be treated by early aggressive gut decontamination and an appropriate management of the haemodynamic complications. In case of lack of effectiveness for stabilisation, plasmapheresis can reduce verapamil related life threatening symptoms and bridge the time for the hepatic detoxification.

Acute Disease↗
PubMed2000

Sleep-apnea in patients with end-stage renal disease and objective results.

BACKGROUND: A high prevalence of sleep apnea syndrome (SAS) of 54%-80% has been reported in patients with end-stage renal disease (ESRD). However, these studies were either done in highly selected small patient groups or without objective data using questionnaires only. PATIENTS AND METHODS: We, therefore, studied the prevalence of SAS in a large, unselected group of patients with ESRD. During a 6-month period 77 out of 84 unselected patients with ESRD filled out the sleep apnea questionnaire of the University of Marburg and the Epworth Sleepiness Scale. In 55 of these patients, snoring sounds, heart rate, body position and transcapillary arterial oxygen saturation were recorded with an ambulatory device during the night after hemodialysis. RESULTS: In the questionnaires, 70.3% of the patients reported of an excessive day-time sleepiness, 40.5% of unwillingly falling asleep during the daytime and 35.2% rated their ability to concentrate as decreased. 30.9% (40% male/15% female) of the patients showed evidence of sleep-disordered breathing with an apnea-hypopnea-index (AHI) equal or more than 5/hour. 16.4% (20% male/10% female) of the patients met the diagnostic criteria of SAS. Neither dialysis and biochemical data nor anamnestic parameters measured by the questionnaires correlated significantly with sleep-disordered breathing. CONCLUSION: The prevalence of SAS in this large unselected patient group was not as high as previously reported, but it is still considerably higher than in the general population. Objective recordings are essential, as questionnaires overestimate the prevalence of SAS in patients with ESRD. As SAS promotes hypertension and impairs quality of life, ESRD patients might benefit from a treatment of concomitant SAS.

Female↗
PubMed1999

[Severe nephrotic syndrome with reversible acute kidney failure in lupus-associated membranous nephropathy].

HISTORY AND CLINICAL FINDINGS: A 20 year old, previously healthy woman presented with a four week history of progressive oedema of the legs and the eyelids and a weight gain of 10 kg. INVESTIGATIONS: Biochemical tests revealed a nephrotic syndrome with a protein-loss in urine of 13.6 g/24 hours and a serum-albumin of 1.2 g/dl. Serological tests showed positive response for antinuclear antibodies, anti-double-stranded-DNA antibodies and cardiolipin antibodies. Renal histology revealed a lupus-associated diffuse membranous nephropathy (WHO-type Vd). DIAGNOSIS, TREATMENT AND COURSE: We first started a treatment regimen with oral steroids and intravenous loop-diuretics without improvement of the nephrotic syndrome. Two weeks after initial presentation the patient developed dialysis-dependent, acute renal failure. Having excluded a renal vein-thrombosis and the transition to diffuse proliferative form of the glomerulonephritis we suggested a nephrotic etiology of the acute renal failure. We initiated cyclophosphamide pulse-therapy which led to dramatic improvement of the nephrotic syndrome after the first cycle with reduction of protein-loss to 6 g/24 hours. Concurrently renal function recovered and treatment with hemodialysis could be stopped after 3 weeks. CONCLUSION: Acute renal failure in nephrotic syndrome has also to be considered in an acute form of a membranous lupus nephritis. Renal recovery is much better when acute renal failure is caused by nephrotic syndrome.

Acute Kidney Injury↗
PubMed1999

Immediate and long-term results of ATG induction therapy for delayed graft function compared to conventional therapy for immediate graft function.

The use of polyclonal antibodies for delayed graft function (DGF) was tested in 83 renal allograft recipients. Conventional immunosuppression (CI) was given to 52 patients with immediate graft function (IGF) while 31 patients with DGF received the polyclonal antibody ATG. Administration of OKT3 was restricted to steroid-resistant acute rejections in both groups. The incidence and severity of acute rejections, graft survival rate, CMV infections, and lymphocyte subsets were examined. ATG patients experienced a total of 0.6 acute rejections per patient, whereas CI patients had 0.9 on the average (P < 0.05). Second and third acute rejections occurred less frequently and later in the ATG group than in the CI group (P < 0.01). Steroid-resistant acute rejections occurred in 20 of the CI patients (38 %) but in only 7 of ATG patients (23 %). One-year graft survival in the CI and ATG groups was 98.1% and 93.2%, respectively. A decreased CD4 + to CD8 + T-lymphocyte ratio of about 0.5 was still detectable 5 years after the initial ATG administration. Hence, patients with DGF appear to benefit from induction therapy with ATG.

Adult↗
PubMed1999

Effects of L-carnitine on leukocyte function and viability in hemodialysis patients: A double-blind randomized trial.

Excess morbidity and mortality among long-term hemodialysis patients because of infectious complications is partly caused by an impairment of cellular immune defense. We hypothesized this impairment is related to an abnormal carnitine metabolism also present in these patients. In a double-blind, randomized, placebo-controlled trial, we investigated the effect of L-carnitine on phagocytic function and viability of blood leukocytes in 17 patients undergoing maintenance hemodialysis. After an observation period of 1 month, the patients received either 10 mg/kg of L-carnitine or placebo intravenously at the end of each hemodialysis session over a period of 4 months. Leukocyte oxidative metabolism was measured by means of luminol-enhanced chemiluminescence and superoxide generation after stimulation with Staphylococcus aureus or phorbol myristate acetate. Killing capacity and phagocytosis of radiolabeled staphylococci were determined. A lactate dehydrogenase (LDH) release test was applied to assess cell viability. We were unable to show an effect of L-carnitine on phagocytic function and viability in vivo. Several clinical parameters were observed during the trial. No statistically significant differences concerning dialysis-related morbidity, anemia, or reduction of blood urea nitrogen and creatinine levels were detected. Additionally, we tested the effect of L-carnitine on phagocytic function after in vitro incubation of blood leukocytes, which also showed no changes. LDH release was decreased, indicating an improved viability of these cells. The latter results were found after in vitro incubation of cells, but could not be confirmed in vivo. In summary, we could not show beneficial effects of L-carnitine administration in hemodialysis patients for the dosage and duration of treatment stated, either on phagocytic function and viability or on the clinical and biochemical parameters observed.

Adult↗
PubMed1999

Pharmacokinetics of morphine and its glucuronides following intravenous administration of morphine in patients undergoing continuous ambulatory peritoneal dialysis.

BACKGROUND: Conjugation with glucuronic acid represents the major route of biotransformation of morphine. The glucuronides morphine-3-glucuronide (M3G) and morphine-6-glucuronide (M6G) are eliminated via the kidneys. Therefore, chronic renal failure should affect the disposition of M3G and M6G. Numerous patients undergoing long-term continuous ambulatory peritoneal dialysis (CAPD) require pain treatment with morphine. There are only limited data available about the disposition of morphine and its active metabolites M6G and M3G in patients on CAPD. We therefore investigated the pharmacokinetics of morphine and its metabolites in CAPD patients. METHODS: This was a single intravenous dose pharmacokinetic study in 10 CAPD patients (1 female, 9 male, age 31-69 years). Morphine-hydrochloride (Mo) (10 mg) was administered intravenously. Serum, urine, and dialysate samples were collected during 24 h. GC-MS-MS and HPLC-MS methods were used to quantify respectively morphine and morphine glucuronides. RESULTS: While systemic clearance of morphine (1246+/-240 ml/min) was in the range observed in patients with normal kidney function, both M3G and M6G showed substantial accumulation. The area under the concentration-time curve (AUC) ratio of M3G:Mo (33.4+/-7.1) and of M6G:Mo (12.2+/-3.2) was 5.5 and 13.5 times higher than in patients with normal kidney function. Renal clearances of morphine, M3G, and M6G (morphine 3.0+/-2.5 ml/min; M3G 3.9+/-2.2 ml/min; M6G 3.6+/-2.2 ml/min) and dialysate clearances (morphine 4.1+/-1.3 ml/min; M3G 3.2+/-0.7 ml/min; M6G 3.0+/-0.8 ml/min) were extremely low. Therefore the accumulation of M6G and M3G is readily explained by kidney failure which is not compensated by CAPD. CONCLUSION: Accumulation of M3G and M6G is due to the substantially lowered clearance by residual renal function and peritoneal dialysis. In view of the accumulation of potential active metabolites, subsequent investigations have to assess the frequency of side-effects in patients on CAPD.

Adult↗
PubMed1999

On-line monitoring of the intravascular volume during haemodialysis by continuous refractometry.

The control of intravascular volume (IVV) by continuous on-line measurement of protein concentration would optimise the patients' specific rate of ultrafiltration. To prove the accuracy of a refractometric device, plasma was continuously drawn by haemofiltration during 10 haemodialysis treatments of male patients. Refractometry reflects highly significant changes in the concentrations of filtrate proteins (r = 0.862, p < 0.001) and blood proteins (rtotal = 0.593, ptotal < 0.001). In vitro, the refractometric device detected a change of protein concentration of 0.041 g/L through a refraction increase of 0.1 mV. The power of discrimination was 0.067% of IVV However, in vivo, the accuracy of IVV refractometric monitoring is reduced by interference factors such as sodium (0. 141 mV/mmol/L), glucose (0.034 mV/mg/dl) and triglycerides (-0.040 mV/mg/dl). Adjustment of the refraction data using sodium and glucose electrodes and plasma filters with a cut-off below the size of chylomicrons is recommended.

Blood Proteins↗