Search PubMed⌕ Search

Biomedical subjects

T Denneberg

Publications and source records attributed to T Denneberg.

At least 55 records · Page 3Linked to original sources

Small intestinal dipeptidases and disaccharidases in uraemic rats on a low protein diet.

Small intestinal dipeptidases (substrate: glycyl-L-leucine, L-methionyl-L-methionine, and L-alanyl-L-proline) were determined in uraemic and sham-operated rats given normal protein diet (24%), low protein diet (6%), and total parenteral nutrition for 10-14 days. Disaccharidases (substrate: maltose, sucrose, trehalose, and lactose) were measured after normal and low protein diet orally. Glycyl-L-leucine and L-methionyl-L-methionine splitting activities were increased on normal protein diet but decreased after low protein feeding in uraemic rats. Parenteral nutrition further lowered the enzyme activity. L-Alanyl-L-proline dipeptidase activity showed an inverse relation to protein intake with the highest values after parenteral nutrition. Lactase increased in uraemic rats after low protein feeding and was the only disaccharidase to be affected by the nutritional change. It is suggested that the changes of the intestinal dipeptidase activities in uraemia are adaptive to variation in the luminal content of di- and oligopeptides because of the type of nutrition given.

Animals↗

Alternative treatment of cystinuria with alpha-merkaptopropionylglycine, Thiola.

Sixteen patients with cystinuria have been treated with Thiola for 0.5-4 years. Only two of the patients had recurrence of stones because of initial inadequate dose. The excretion of free cystine and the mixed Thiola-cysteine disulphide in the urine has been measured on an automatic amino acid analyser. Thiola has less side effects than D-penicillamine with respect to bone marrow, kidney, liver, gastrointestinal tract and skin. No chelating properties on urinary excretion of copper and zinc were observed during Thiola treatment. We conclude that successful treatment will depend on determining an individual dose of Thiola for every patient and from monitoring free cystine and Thiola-cysteine disulphide in the urine.

Adolescent↗

Plasma free amino acid levels in uremic rats given high and low protein diets or intravenous infusions of amino acid solutions.

Plasma free amino acids were measured in uremic and sham-operated rats fed for 10 days a high (24%) or a low (6%) protein diet or given total parenteral nutrition, either with a complete amino acid solution or a solution containing only the amino acids considered to be indispensible in uremia. The plasma levels of citrulline, glycine, hydroxyproline, and 1- and 3-methylhistidine were elevated in all uremic rats compared with the corresponding controls. Plasma tryptophan was reduced in three out of four uremic groups and the brached-chain amino acids and tyrosine were reduced in plasma of orally fed uremic rats but not after intravenous infusion. Plasma serine increased with increased plasma glycine levels. The ratio serine:glycine was, however, significantly smaller in the uremic rats. The ratios of plasma valtine:glycine and indispensable:dispensable amino acids were affected by nitrogen intake as well as by uremia, whereas plasma citrulline:tryptophan was influenced only by the uremic state. This ratio was markedly elevated in all uremic groups. The alterations observed in the plasma free amino acid levels and ratios of the uremic rats were similar to those reported from clinical observations on patients with chronic renal failure.

Amino Acids↗

Effects of total parenteral nutrition in rats with experimental chronic renal failure.

The effects of total parenteral nutrition (TPN) in partially nephrectomized rats (n = 17) and sham-operated controls (n = 12) were evaluated and compared to the effect of low and high nitrogen oral diets (6% and 24% protein). TPN included fat (9 g/kg per day), high energy (1385 KJ/kg per day), and low nitrogen content (0.6 g N/kg per day, corresponding to 8% protein) either as essential amino acids (EAA) or as a mixture of essential and nonessential amino acids (CAA). The parenteral nutrition was administered intravenously via a permanent catheter continuously for 10 days. Most animals tolerated the treatment with no signs of overhydration or electrolyte imbalances. Uremic rats on TPN gained in weight similarly to control animals, whereas uremic rats given oral diets showed a lower weight increase. Both amino acid solutions promoted positive nitrogen balance and growth. Plasma urea dropped during TPN and low protein oral feeding in uremic and control rats, but not in the high protein-fed animals. Serum creatinine decreased with TPN but not with oral feeding in uremic rats. Albumin and hemoglobin levels were significantly reduced in all uremic rats irrespective of dietary treatment. The experimental model presented here could be useful for further studies on parenteral nutrition in uremia.

Amino Acids↗

Effects of chronic uremia on bone.

Iliac crest bone biopsies in patients with chronic renal failure with severely disturbed renal function were measured with regard to osteoclast activity and active and inactive osteoid. In none of the 21 patients had hemodialysis been applied. In uremia cases, as earlier demonstrated in hemodialysis cases, the alkaline phosphatase and the parathyroid hormone activity were the best variables for prediction of bone complications. However, none of the laboratory variables or all taken together could predict the type of bone changes. The osteoclast activity was less than in hemodialysis cases indicating that secondary hyperparathyroidism may be less important in the non-hemodialysed cases.

Adult↗

Glomerulonephritis in infections with Yersinia enterocolitica O-serotype 3. II. The incidence and immunological features of Yersinia infection in a consecutive glomerulonephritis population.

In a consecutive series of 38 patients with acute glomerulonephritis (GN), 17 showed serological or immunological signs of current or previous yersiniosis. None of these 17 patients had raised antistreptolysin-o titres. Only half of these patients had had clinical symptoms of Yersinia infection. Light microscopic examination revealed that 12 of the 17 patients had proliferative and 4 epimembranous GN. In 8 out of 14 biopsy specimens, Yersinia antigen could be demonstrated by immunoglobulins and complement. Immunofluorescence microscopy examination of all biopsy specimens containing sufficient tissue for a valid analysis showed deposits of complement and immunoglobulin G, most specimens also immunoglobulins A and M. It is considered highly likely that Y. ent. O:3 may be, and frequently is, an etiological factor for development of acute GN. It would be advisable not only to investigate all patients with acute GN for streptococcal infections, but also to carry out serological and bacteriological tests for Y. eng. O:3 infection and to institute an active therapeutic approach to acute infections caused by this bacterium.

Acute Disease↗

Glomerulonephritis in infections with Yersinia enterocolitica O-serotype 3. I. Evidence for glomerular involvement in acute cases of yersiniosis.

Signs of damage to the glomerular basement membrane appearing as haematuria and proteinuria have been observed in 16 cases of proven acute yersiniosis. The infecting agent was Yersinia enterocolitica serotype O:3 in all. In a few cases a transient deterioration of the renal function was observed. The renal symptoms were not related to the acute febrile state, but seemed to appear about 14 days after the onset of yersiniosis and to be reversible in the observation period. Infection with other microorganisms known as nephritogenic was not found in spite of attempts to do so. Kidney biopsy was performed in one case and immunofluorescence microscopy showed deposits of immunoreactants. Based on these observations we suggest that acute glomerulonephritis can be included in the spectrum of complications of infection with Yersinia enterocolitica serotype O:3. The frequency of complicating glomerulonephritis in yersiniosis could not be estimated from this study.

Adolescent↗

Small intestinal dipeptidases and disaccharidases in experimental uremia in rats.

Rats were made severely uremic with partial nephrectomy (24-hour creatinine clearance 10% of normal). Jejunal dipeptidase activities (substrates: glycyl-L-leucine, L-alanyl-L-proline, and L-methionyl-L-methionine), disaccharidase activities (maltase, sucrase, trehalase, and lactase) and morphology were studied. A highly significant increase in glycyl-L-leucine and L-methionyl-L-methionine dipeptidases was found in uremic rats compared with controls. Proline dipeptidase activities were unaltered. Disaccharidase activities showed a slight increase in sucrase in uremic rats; otherwise no change was found.

Animals↗

Netilmicin therapy of serious renal and urinary tract infections in patients with normal and impaired renal function.

29 patients with serious renal or urinary tract infections were treated with netilmicin (initial dose 1.5 mg/kg twice daily). All but two patients were bacteriologically cured and responded well clinically. 13 patients with initial renal impairment were analysed separately. Whereas the patients with initial normal renal function did not show any increase of serum creatinine levels during and after treatment, the patients with renal impairment showed a significant increase of serum creatinine during the course of treatment, but no clinical signs of renal function deterioration. During the follow-up period (18 months), serum creatinine values in all cases but one returned to the pretreatment levels. Thus, the investigation revealed that netilmicin had a good clinical and bacteriological effect without signs of persistent renal damage.

Adult↗

Pharmacokinetic and therapeutic studies of pivmecillinam in patients with normal and impaired renal function.

Pivmecillinam which is the oral form of mecillinam was evaluated by treatment of 26 patients presenting various types of urinary tract infections and by prophylactic treatment of 12 patients. Pivmecillinam given in a daily dosage of 1.2 g for periods of 1 to 56 weeks was well tolerated in all of the patients including those with impaired renal function without any dose reduction. The original bacterial strain in the urine was eradicated in 100% of the cases. Two patients had a superinfection and 4 had a recurrence during a 3-month follow-up period. The oral absorption of pivmecillinam was investigated in 15 patients with normal or slightly reduced renal function and in 5 patients on maintenance hemodialysis. High serum levels were achieved within 1 to 2 h after administration. Patients with reduced renal function showed retarded elimination rates, suggesting that the dose should be adjusted in this category of patients.

Acute Kidney Injury↗

Hemolytic uremic syndrome. Results of treatment with hemodialysis.

The characteristics of the hemolytic-uremic syndrome in 7 children living in a well defined area in the south of Sweden are described. All the patients had a severe form of the disease and were critically ill. The clinical activity could best be followed by measuring blood platelets and urinary FDP. Early institution of hemodialysis treatment, given almost daily until normalisation of platelet count and urinary output, is the most important live-saving measure. Full dosage heparin seems not to be necessary. Six patients survived and were followed-up for 1-7 years. When last seen they all had normal renal function and blood pressure.

Blood Cell Count↗

Cytomegalovirus hepatitis in an artificial kidney unit.

Serum hepatitis is a dreaded risk in connection with regular dialysis treatment (RDT). Liver damage, however, can be cuased by other diseases, such as infection with cytomegalovirus (CMV). Two cases in our artificial kidney unit revealed signs of liver damage with increased liver enzyme activity. Case 1, a woman, was on RDT after an unsuccessful renal transplantation, and Case 2, a man, belonged to the staff. Serum hepatitis was initially suspected in both cases, but repeated examinations of the sera revealed no hepatitis B antigen or antibodies (HbAg and HbAb). Later on, both showed a significant increase in antibodies in complement fixations reaction (CF) to CMV-antigen. CMV could be isolated from urine in Case 2. Case 1 had been bilaterally nephrectomized. The symptoms (tiredness, muscle pain and headache) and the course of the disease were mild in both cases and liver enzymes became normal within 1-2 weeks. Twenty out of 31 examined patients and staff had antibodies in CF to CMV-antigen, but in none was there any significant increase. The source of infection may have been transfusion of fresh blood in Case 1, but in Case 2 no particular source could be suspected. Thus, in liver damage CMV-infection may be an etiological alternative. In routine work at artficial kidney unite patients and personnel are regularly examined in respect of bilirubin, liver enzymes, HbAg and HbAb in serum. We recommend also examination of serum for antibodies in CF to CMV-antigen. Until a firm differential diagnosis has been established the patient should be isolated and the dialysis equipments used only by that patient.

Adult↗

Co-trimoxazole in the long-term treatment of pyelonephritis with normal and impaired renal function.

The effect of co-trimoxazole was studied in 29 cases of acute or chronic pyelonephritis. The therapy produced the desired effect in 22 out of 23 cases and in the 6 cases treated prophylactically. We used a special dosage schedule for the combination of sulphamethoxazole and trimethoprim in the treatment of patients with normal renal function and with varying degrees of renal impairment. The results show that the plasma concentrations were at satisfactory therapeutic levels, with no accumulation of the three substances and without causing any toxic side effects, even in patients with severe impairment of the renal function. The mean duration of the treatment was 12.3 months. The material is, however, not largelu enough to warrant the recommendation of standardized treatment according to the schedule described, in spite of the favourable experience gained. It does, however, permit us to recommend that the plasma concentrations should be determined, particularly of the total sulphamethoxazole in patients with severely impaired renal function.

Acute Disease↗