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Biomedical subjects

O Jonsson

Publications and source records attributed to O Jonsson.

At least 37 records · Page 2Linked to original sources
PubMed1997

Examination of intrarenal blood flow by Doppler ultrasound before and after extracorporeal shock wave lithotripsy for urolithiasis.

This study was aimed to test whether therapeutical extracorporeal shock wave lithotripsy (ESWL) may induce changes in renal parenchymatous blood flow, thereby indirectly indicating shock wave side effects on the renal parenchyma. In 18 patients, a Duplex ultrasound investigation of both kidneys was performed before and after ESWL. Pulsatility Index (PI), which is an estimation of renovascular resistance, increased in both treated and untreated kidney. However, the increase was confined to a subgroup of seven patients, who had received meperidine (a morphine analgetic) for analgesia. This increase is more likely to be due to a pharmacological effect of meperidine rather than a direct effect of ESWL on renal hemodynamics. In conclusion, we did not find any evidence of ESWL related affection of renal blood flow measured with duplex ultrasound, a technique sensitive enough to detect changes in renal hemodynamics due to morphine analgetics.

Adult↗
PubMed1997

Serum levels of IgG antibodies against Tamm-Horsfall protein and urinary excretion of NAG and alpha-1-microglobulin as possible markers for tubular damage in patients with a continent ileal reservoir for urinary diversion.

Serum IgG antibodies against Tamm-Horsfall protein and urinary excretion of NAG and alpha-1-microglobulin were measured in 26 patients with a Kock reservoir for continent urinary diversion or orthotopic bladder reconstruction in order to detect any signs of tubular damage. None of these markers for tubular damage was correlated to the postoperative observation time ranging between 2 and 16 years. No correlation was found between these markers and signs of renal scarring or upper urinary tract dilatation as judged from urographies. A positive correlation was demonstrated between NAG excretion and antibodies against Tamm-Horsfall protein. The annual reduction in GFR was increased in patients with elevated alpha-1-microglobulin excretion but not in patients with elevated titres of antibodies against Tamm-Horsfall protein or increased NAG excretion. Patients with previous or present reflux nipple problems had elevated excretion of alpha-1-microglobulin. Regular determinations of alpha-1-microglobulin excretion appear to be of value in the follow-up of these patients.

Acetylglucosaminidase↗
PubMed1997

A study of phage- and ribotype patterns of Staphylococcus aureus isolated from bovine mastitis in the Nordic countries.

This study was conducted to investigate the geographical distribution of phage and ribotypes of Staphylococcus aureus causing bovine mastitis in the 5 Nordic countries. A total of 403 isolates of S. aureus was isolated from 403 different dairy herds. One hundred five strains were isolated in Denmark, 81 in Finland, 17 in Iceland, 96 in Norway and 104 in Sweden. The isolates were phage typed and characterized for their EcoRI restriction fragment length polymorphisms of the genes encoding ribosomal RNA (ribotyping). A total of 351 (87%) of the 403 isolates could be typed by phages assigning them to 25 different phage types. Two to 3 different phage types predominated within each country. One type (29/52) accounted for 36% of all the isolates and was found in 4 of the countries. A total of 87 different ribotypes was found among the isolates investigated. As for phage typing 2 to 3 different types predominated within countries. However, except for one type (ribotype 1), which was commonly found in Denmark, Sweden and Finland, different ribotypes predominated within each country. The combination of phage and ribotyping assigned the isolates to 178 different types. Ninety-six percent of the isolates of ribotype 1 belonged to phage type 29/52. This combined type accounted for 17% of all the 403 isolates. These findings show that a large number of different types of S. aureus can be isolated from cases of bovine mastitis. However, few types predominate within different countries. These predominating types seem to be specific in each country, however, a single type was common for both Denmark, Sweden and Finland. This could suggest differences in the virulence or in modes of transmission of predominating and rare types of S. aureus associated with bovine mastitis.

Animals↗
PubMed1996

Effect of a new inhibitor of lipid peroxidation on kidney function after ischaemia-reperfusion. A study on rat and rabbit kidneys.

Lipid peroxidation of mitochondrial and cell membrane structures is the final step in the oxygen radical-induced damage observed at reperfusion of kidneys after ischaemia. We compared the ability of an indeno-indol compound (code name H290/51) with that of alpha-tocopherol to inhibit lipid peroxidation in reoxygenated isolated rat renal tissue in vitro measured as production of TBARS (thiobarbituric acid reactive substances). H290/51 was 100 times more efficient than alpha-tocopherol. Treatment of rats in vivo with H290/51 in a dosage giving a plasma concentration of 500 nmol L-1 inhibited TBARS production measured in vitro by 80%. Treatment of rabbits with H290/51 almost completely inhibited radical production at reperfusion after 60 min of ischaemia measured with spin trap technique using OXANOH (2-ethyl-3-hydroxy-2,4,4-trimethyloxazolidine) as a spin trap. Furthermore, such pretreatment significantly improved kidney function and survival of rabbits subjected to 60 min of ischaemia to the left kidney and contralateral nephrectomy. These studies stress the importance of inhibiting lipid peroxidation to prevent the ischaemia-reperfusion damage and furthermore suggest a role for treatment with antioxidants like H290/51 in clinical practice, e.g. at reconstructive renal surgery and transplantation.

Animals↗
PubMed1996

Concrement formation and urease-induced crystallization in urine from patients with continent ileal reservoirs.

OBJECTIVES: To study the relationship between urinary tract infection, urine composition and concrement formation in patients with continent ileal reservoirs for urinary diversion. PATIENTS AND METHODS: The study comprised 27 patients (seven men and 20 women, mean age 47 years, range 23-76) with continent ileal reservoirs who were followed for a mean of 67 months (range 13-146) by annual reservoiroscopy, intravenous urography and urine culture; at the final follow-up, a sample of their morning urine was analysed for a range of compounds and the number and size of any particles present or produced in response to incubation with urease. RESULTS: The presence of urease-producing bacteria was associated with the formation of concrement. However, a few patients in whom an infection with urease-producing organisms was not detected also formed concrement. Urine from those patients forming stones tended to have a high calcium and a low citrate concentration. After incubation with urease, significantly more and larger particles were formed in the urine from stone formers. There was a strong correlation (r = 0.8) between urinary calcium content and urinary pH when the urease-induced precipitation commenced, and between urinary calcium and the size and volume of the crystals developed (r = 0.9) after 4 h of incubation. CONCLUSIONS: There are many factors which might influence the formation of concrement, e.g. outflow conditions, the presence of staples or infection in the reservoir, and the composition of the urine is also important. It thus appears appropriate to determine if measures to reduce urinary calcium and increase urinary citrate can decrease the episodes of stone formation in those patients with continent ileal reservoirs for urinary diversion who frequently form stones.

Adult↗
PubMed1996

Stabilization of the nipple base with titanium rings when reoperating patients with continent urostomies for nipple dysfunction.

Nipple dysfunction in Kock reservoirs used for continent urinary diversion is usually caused by a flattening out of the intestinal nipple due to a lateral tore at the base of the nipple when the reservoir expands. This study describes a new method to repair dysfunctioning nipples based on the use of titanium rings applied outside the reservoir around the base of the nipple. Experiments on dogs and rats have shown that rings and plates of titanium rapidly attach to the serosal surface of ileum exposed to urine with only minor signs of inflammation. Ten patients with Kock reservoirs for urinary diversion have been reoperated for nipple dysfunction due to nipple sliding with elongation of the nipple and fixation of the nipple base with titanium rings. The functional result is excellent in 9 out of the 10 patients. No signs of erosion of the rings into the reservoirs have been noted. With this new method for nipple repair the need for using more intestine to construct a new nipple is eliminated.

Adult↗
PubMed1996

Bone mineral and related biochemical variables in patients with Kock ileal reservoir or Bricker conduit for urinary diversion.

PURPOSE: Bone material content was studied with single photon absorptiometry and dual energy x-ray absorptiometry , and the various biochemical parameters related to bone metabolism in patients with Kock reservoirs or Bricker conduits for urinary diversion. MATERIALS AND METHODS: We examined 34 patients with Kock ileal reservoirs to the skin (29) or urethra (5) and 14 with Bricker conduits 2 to 17 years after urinary diversion. Bone mineral density was measured in the radius with single photon absorptiometry, and in th femur, lumbar spine and whole body with dual x-ray absorptiometry. Serum concentrations of 25-hydroxyvitamin D, 1,25-dihydroxyvitamin D, osteocalcin, parathyroid hormone, bone specific alkaline phosphatase and ionized calcium were determined. Arterial blood gases were analyzed. RESULTS: The mean values for bone mineral density did not differ from age-matched controls in either group and no signs of decrease were observed with followup. Vitamin D serum concentration values remained within normal limits in all patients. Most patients had normal blood gas values. Mean values for osteocalcin, parathyroid hormone, bone specific alkaline phosphatase and ionized calcium also were within normal limits, although a few patients had elevated osteocalcin values indicating increased bone turnover. CONCLUSION: Urinary diversion with a Kock reservoir or Bricker conduit did not cause bone demineralization of significant changes in different markers of bone metabolism in patients examined 2 to 17 years after urinary diversion.

Absorptiometry, Photon↗
PubMed1995

Clean intermittent catheterization in spinal cord injury patients: long-term followup of a hydrophilic low friction technique.

Clean intermittent self-catheterization is an established option in bladder management of spinal cord injury patients. Several early and a small number of long-term studies have reported good preventive or therapeutic effects on hydronephrosis, vesicourethral reflux, urinary tract infection and incontinence. Most reports describe the use of small catheters and liberal use of jelly but urethral complications, such as strictures and false passages, seem to increase with the length of followup. All 30 spinal cord injury patients in this retrospective study had used disposable hydrophilic, low friction catheters from the early shock phase to a median of 7 years (range 5 to 9). There were 26 upper motor neuron and 4 lower motor neuron lesions. After tap water soaking, the surface layer of the catheter coating has a friction constant more than 10 times lower than that for a regular plastic catheter (Nélaton) with chlorhexidine jelly. There was no hydronephrosis, pyelonephritis or renal scarring. In 3 patients who had decreased the clean intermittent self-catheterization regimen, signs of upper tract dilatation developed but the excretory urogram returned to normal after correction of the regimen. Of 30 patients 12 (40%) maintained sterile urine, while 4 of the remaining 18 with bacteriuria had episodes of urinary sepsis and chronic infections. Two patients had epididymitis. Of 6 men with occasional insertion difficulties when the clean intermittent self-catheterization regimen started after the indwelling catheter had been removed 4 showed yielding signs of strictures during the subsequent clean intermittent self-catheterization regimen. In 1 patient 2 dilation attempts had failed but the patient can perform the clean intermittent self-catheterization regimen. One patient with Crohn's disease had advanced urethral changes in the acute phase but could perform clean intermittent self-catheterization with a small catheter. One patient has had recurrent modifications of the urethral wall but no development of a false passage. The study indicates that patients who use hydrophilic low friction low friction catheters do as well as or better than patients using conventional catheters. Above all, there is no increase in severe urethral complications with time after injury. Progression towards strictures after early urethral trauma seems to be preventable by the use of this catheter.

Adult↗
PubMed1995

Effect of pre-treatment with desferrioxamine and mannitol on radical production and kidney function after ischaemia-reperfusion. A study on rabbit kidneys.

The effects of pre-treatment with mannitol and the iron chelator desferrioxamine on oxygen radical formation and glomerular and tubular function after ischaemia in the rabbit kidney were studied. Radicals were measured with ESR and spin trapping. At reperfusion after 60 min of renal ischaemia there was a significant increase in the production of free radicals in the venous effluent from the kidney. Administration of either mannitol or desferrioxamine given before ischaemia and before recirculation reduced the radical production significantly. The iron chelator appeared to be more effective. Glomerular function measured 48 h after reperfusion was significantly better after pretreatment with desferrioxamine and mannitol compared with mannitol alone. Tubular function did not differ between the two pre-treatment groups.

Animals↗
PubMed1994

Identification of potassium flux pathways and their role in the cytotoxicity of estramustine in human malignant glioma, prostatic carcinoma and pulmonary carcinoma cell lines.

Clinically-used drugs such as furosemide, bumetanide and cardiac glycosides, are modulators of transmembrane fluxes of cations. Recently, it has been suggested that the regulation of intracellular cation concentrations could be a primary target for anti-neoplastic drugs, and that the cytotoxic activity may be altered by inhibitors of cation fluxes at the level of the plasma membrane. Therefore, we investigated the mechanisms by which cations are translocated across the plasma membrane of malignant glioma (U251 MG), prostatic carcinoma (PC3) and pulmonary carcinoma (P31) cell lines. The interactions between cation flux inhibitors and the cytotoxicity of estramustine were also evaluated. Ouabain, the classical inhibitor of Na+, K+ATPase, markedly reduced 86Rb (K+) influx in all three lines, indicating that this ion transport system is present in the cells. Furosemide and especially bumetanide inhibited the 86Rb influx, indicating the presence of the Na+, K+, Cl- co-transport system. The potassium channel blocker, tetraethylammonium, but not apamin reduced the influx of 86Rb showing that high conductance K+ channels are present, but that channels of low conductance probably do not exist in these cell lines. The Na+, K+, Cl- co-transport inhibitors furosemide and bumetanide significantly reduced cytotoxicity of estramustine in P31 cells, whereas no interaction between other K+ flux inhibitors and the anti-neoplastic drugs were detected in any of the cell lines investigated. Thus, the data show that Na+, K+, ATPase and NA+, K+, Cl- co-transport systems and K+ channels of high conductance are present in malignant glioma (U251 MG), prostatic carcinoma (PC3) and pulmonary carcinoma (P31) cell lines, and that inhibition of the Na+, K+, Cl- co-transport system in P31 is associated with reduced cytotoxicity of estramustine. The results justify further studies evaluating the role of these cation flux pathways in terms of targets for anti-neoplastic therapy.

Bumetanide↗
PubMed1994

Effect of recombinant human growth hormone on cellular sodium metabolism.

1. The effect of treatment with recombinant human growth hormone on urinary sodium excretion, total body water, the renin-angiotensin system and erythrocyte sodium metabolism was investigated in 16 adults with growth hormone deficiency. 2. Total body water was determined by isotopic dilution, and erythrocyte electrolyte contents were analysed using flame photometry. The rate of sodium influx and the efflux rate constant of sodium were calculated from values of 22Na in erythrocytes in vitro. 3. One week of treatment with recombinant human growth hormone caused a decrease in urinary sodium excretion in 9/10 patients and an increase in erythrocyte sodium content. Total body water, plasma renin activity, angiotensin II concentration and transmembrane sodium transport were unaltered. 4. Six months of treatment with recombinant human growth hormone caused significant increases in total body water, erythrocyte sodium content and sodium transmembrane influx. Plasma renin activity tended to increase, whereas blood pressure and serum sodium and potassium concentrations remained unchanged. After 6 months on recombinant human growth hormone total body water showed a significant negative correlation with plasma renin activity. 5. The enhanced erythrocyte sodium transport, if this reflects what happens in the renal tubular cell, combined with a decrease in urinary sodium excretion, during treatment with recombinant human growth hormone could indicate an increase in tubular sodium reabsorption induced by the hormone. An increased plasma renin activity associated with the lack of blood pressure rise would reinforce sodium and water retention.

Adult↗
PubMed1994

Bacteriuria in patients with a continent ileal reservoir for urinary diversion does not regularly require antibiotic treatment.

OBJECTIVE: To elucidate the importance of bacteriuria in patients with a continent urinary diversion. PATIENTS AND METHODS: Eighteen asymptomatic patients (16 women and two men, with a mean age of 53 years [range 22-73]) with ileal reservoirs coupled to the skin for urinary diversion were studied. Consecutive urine cultures were performed over 5 months. Concomitant measurements of antibody titres against Escherichia coli and Proteus, and C-reactive protein (CRP) values were made. RESULTS: The results of the urine cultures varied considerably between samples. Increased titres of antibodies against E. coli were seen in several patients but the correlation with bacteriuria caused by E. coli was weak (sensitivity 33%, specificity 56%). Increased titres of antibodies against Proteus were rarely seen and in no patient correlated with bacteriuria caused by Proteus. Increased levels of CRP were seen in three patients. CONCLUSION: The present results indicate that asymptomatic bacteriuria in patients with a continent ileal reservoir for urinary diversion is generally of no clinical importance and should not be treated with antibiotics. This conclusion is based on the observations that the bacterial strains growing in the reservoir changed spontaneously indicating colonization rather than infection. Raised titres of antibodies against E. coli correlated weakly with bacterial growth. The observed elevations in antibody titres were usually just above the normal upper limit.

Adult↗
PubMed1994

Influence of pH on reservoir mucosal absorption/-secretion and tubular and glomerular function. Studies in patients with a continent ileal reservoir for urinary diversion.

Ten patients with a continent ileal reservoir for urinary diversion were studied regarding transmucosal fluxes of water and electrolytes at different pH. The urine was by-passed the reservoir via a Foley catheter. The experiment set-up was designed to exclude urine from reservoir mucosa exposition during the study. Test solutions of pH 4 and pH 7 with electrolytes and a non-absorbable volume marker (PEG MW 4000) were instilled into the empty reservoir. The influence of altered pH on the flow of water and Na,+K+ and Cl- across the reservoir mucosa was analysed. The maximal concentration ability after intranasal desmopressin (Minirin), the creatinine and Na-clearance as well as the fractional Na-excretion were calculated from measurements on the by-passed urine. The results showed a secretion of water, Na+ and Cl- into the reservoir while the K+ content was constant. The mucosal flows of water and electrolytes were not affected by alterations in reservoir pH. Maximal concentration ability appeared to be reduced compared to normals. Fractional Na excretion was within normal limits.

Adult↗
PubMed1994

Relationship between change in erythrocyte sodium and antihypertensive response to enalapril.

To investigate the effects of enalapril and hydrochlorothiazide on erythrocyte sodium and potassium in relation to their effects on BP, 28 men (mean age 46 years, range 22-64 years) with previously untreated essential hypertension (casual DBP > or = 95 mmHg) were randomised to enalapril (n = 14) or hydrochlorothiazide (n = 14) treatment. BP was also measured intraarterially (brachial artery) and the mean arterial pressure (MAP) recorded. Intraerythrocyte sodium and potassium were measured by flame photometry at baseline and after 26 weeks of active treatment in the hypertensive patients and also in 28 age- and sex-matched normotensive control subjects. There was a significant positive relationship between intra-arterial BP and intraerythrocyte sodium in untreated hypertensives, but there was no significant difference in mean intraerythrocyte sodium or potassium content between hypertensive and normotensive subjects at baseline. The distribution of values of intraerythrocyte sodium, however, differed between hypertensive and normotensive subjects. Supine MAP was lowered from 113 +/- 4 to 97 +/- 3 mmHg and from 110 +/- 3 to 102 +/- 2 mmHg on enalapril and hydrochlorothiazide treatment, respectively. BP reduction with enalapril was associated with a significant decrease in intraerythrocyte sodium (P = 0.02), while hydrochlorothiazide had no effect. There was no significant correlation between delta MAP and delta intraerythrocyte sodium after 26 weeks in any of the groups. Intraerythrocyte potassium did not change on treatment with either drug. In conclusion, there wa a significant relationship between intra-arterial BP and intraerythrocyte sodium in untreated hypertensives. Both enalapril and hydrochlorothiazide reduced BP effectively while enalapril only reduced intraerythrocyte sodium.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

ESR-measurement of oxygen radicals in vivo after renal ischaemia in the rabbit. Effects of pre-treatment with superoxide dismutase and heparin.

The effects of intracellular and extracellular superoxide dismutase and heparin administration on oxygen radical formation after ischaemia in the rabbit kidney were studied. Radicals were measured with ESR and spin trapping. At reperfusion after 60 min of renal ischaemia there was a significant increase in the production of free radicals in the venous effluent from the kidney. Administration of either intracellular superoxide dismutase or extracellular superoxide dismutase before ischaemia and before reperfusion prevented approximately 85% of the radical formation seen in the untreated control group. Administration of heparin 5 min before recirculation resulted in a 65% decrease in radical production compared to the control group.

Animals↗