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Biomedical subjects

G Nyberg

Publications and source records attributed to G Nyberg.

At least 73 records · Page 4Linked to original sources

Latent overhydration and nocturnal hypertension in diabetic nephropathy.

With the aim of studying the diurnal variation in blood pressure in relation to degree of fluid retention, 24-h ambulatory blood pressure monitoring was performed in 31 insulin-dependent diabetic patients with nephropathy. The extracellular volume was calculated from the distribution volume of 51Cr-EDTA after a single injection. The study population was arbitrarily divided into two groups, depending on their extracellular volume. Group 1 included 15 patients with a lower extracellular volume and group 2, 16 patients with a higher extracellular volume. Ambulatory blood pressure was measured with a portable monitor using an oscillometric technique. In all patients, the mean +/- SD 24-h ambulatory blood pressure was 135/79 +/- 14/7 mmHg. Day and night-time blood pressure were 136/81 +/- 14/7 and 133/75 +/- 17/8, respectively (p < 0.02). The ambulatory blood pressure was 135/80 +/- 14/7 in group 1 and 136/78 +/- 15/6 mmHg in group 2. The nocturnal change in blood pressure was significantly greater in group 1 than in group 2, -9/-9 +/- 10/5 mmHg and 1/-3 +/- 10/6 mmHg, respectively (p = 0.005/0.01). There were no other significant differences between the groups than the diurnal blood pressure pattern. There were significant correlations between day ambulatory blood pressure and night ambulatory blood pressure and 24-h ambulatory blood pressure and urinary albumin excretion. There was no correlation between ausculatatory clinic blood pressure on the one hand and albuminuria on the other. Latent fluid retention therefore may contribute to nocturnal hypertension in diabetic nephropathy.

Adult↗

A quantitative ultrastructural study of juxtaglomerular arterioles in IDDM patients with micro- and normoalbuminuria.

Hyalinization of juxtaglomerular arterioles is prominent in advanced diabetic nephropathy and may have important functional consequences. We studied the early stages of diabetic renal disease using kidney biopsy material from insulin-dependent diabetic patients, 8 with normal albumin excretion rate (< 15 micrograms/min) and 16 with microalbuminuria (15-200 micrograms/min). Ten living non-diabetic kidney donors served as a control group. Median duration of diabetes was 9.5 years (range 5-31) in patients with normoalbuminuria, and 12 years (7-22) in patients with microalbuminuria (p = 0.27). The tissue was sectioned systematically, 1-micron thick sections for light microscopy at 10-micron intervals, and thin sections for electron microscopy taken at 60-micron intervals. The arterioles were identified as afferent or efferent, and total profiles were photographed (magnification 7500x), providing a systematic independent sample for measurements using standard stereological methods. Patients with microalbuminuria had significantly increased arteriole parameters compared with the control group: for afferent and efferent arterioles the volume fraction of matrix/media, means and (co-efficient of variation, CV), was 0.47 (0.16) vs 0.33 (0.19) (p = 0.0009), and 0.62 (0.14) vs 0.45 (0.23) (p = 0.0004) and matrix-T, expressing amount of matrix per unit arteriolar surface, 2.38 (0.38) micron vs 1.44 (0.30) micron (p = 0.004), and 1.62 (0.28) micron vs. 1.03 (0.34) (p = 0.0009). Patients with normoalbuminuria showed no significant differences from the control group, and had lower values than microalbuminuric patients for all parameters except the afferent matrix-T. In the normoalbuminuric group a correlation was found between parameters for afferent arterioles and those for glomerular structure. In conclusion there is arteriolar accumulation of extracellular material in the early phase of diabetic nephropathy, concomitant with early glomerulopathy.

Adolescent↗

Glomerular epithelial foot processes and filtration slits in IDDM patients.

Diabetic nephropathy is associated with functional changes in the glomerular filtration barrier but the structural counterpart remains unknown. Width of glomerular epithelial cell foot processes and of filtration slits were determined by morphometric methods in 11 non-diabetic kidney donors and in 28 diabetic patients with albumin excretion rates ranging from normal to proteinuria. Foot process width was estimated from the ratio of tuft surface density to length density of slits. At high magnification independently sampled, perpendicularly cut slits were classified. Foot process width on peripheral basement membrane was increased in microalbuminuric compared to normoalbuminuric diabetic patients (p<0.05) but showed no significant correlation with the level of albumin excretion when patients with increased barrier permeability were considered. Width of filtration slits in normo- and microalbuminuric diabetic patients exceeded that in non-diabetic control subjects (p<0.05). Filtration slits were narrower in patients with overt proteinuria than in patients with microalbuminuria (p<0.05) and correlated with glomerular filtration rate in all of the diabetic patients (r=0.65, p<0.005). The results show that insulin-dependent diabetic patients with nephropathy present changes of epithelial cells and filtration slits, demonstrable already in the stage of microalbuminuria. The mechanism of albumin leakage is not achieved by these measures. The dimension of filtration slits may play a contributing role in the level of glomerular filtration rate in diabetic patients.

Adolescent↗

Cost-effectiveness studies of renal transplantation.

This study analyzes opportunity costs for the treatment of end-stage renal disease. Kidney transplantation remains the most cost-effective treatment for uremia and is one of the most cost-effective technologies in health care. Improved survival of grafts and increased numbers of transplants have the potential to reduce costs for dialysis programs. To support organ donation activities, the public and concerned health professionals should be informed about the opportunity cost of "unnecessary" dialysis. These resources could be reallocated from dialysis to other programs. Among patients in dialysis, a more common use of chronic ambulatory peritoneal dialysis instead of institution-based hemodialysis would greatly increase cost-utility and further reduce the program costs of renal replacement therapy.

Adult↗

Original renal disease in a kidney-transplant population.

Classification of the underlying renal disorder in kidney transplant patients involves some uncertainties. To allow evaluation of the risk of recurrence of renal disease in the transplanted kidney and other characteristics and risks inherent to the specific renal disorder we have investigated the basis for and reevaluated the diagnosis of 1000 consecutive patients who received transplants in Göteborg 1985-1993. In the original registry, 36% of patients had been given the diagnosis chronic glomerulonephritis but the diagnosis was confirmed by biopsy in only half of them, 18% of the total population. Systemic vasculitides and hereditary disorders other than adult polycystic kidney disease which constituted 3% and 6%, respectively, had frequently been overlooked. The term chronic pyelonephritis (15%) covered a variety of conditions including toxic tubulointerstitial disease, but was dominated by those caused by congenital urinary tract formations. Diabetic nephropathy (21%) was the consequence of Type 1 diabetes in 18% and Type 2 or other forms of diabetes in 3%. The proportion of patients with unknown cause of renal failure was 20%. The registry allows identification of small, distinct entities, which may be characterised as regards prerequisites for and consequences of kidney transplantation.

Aged↗

Spectrum of hereditary renal disease in a kidney transplant population.

Re-evaluation of the underlying renal disease in 1000 consecutive kidney transplant patients revealed 129 cases of adult autosomal dominant polycystic kidney disease and 60 clear and seven suspected cases with other hereditary renal disorders. Twenty-four of 60 patients had cystic/dysplastic disease--10 of these classified as nephronophthisis, five as polycystic disease, and nine with the renal affection as part of a congenital malformation syndrome. Thirteen patients had Alport's syndrome, nine were diagnosed with tubulointerstitial nephritis, and six had an adult form of focal segmental glomerular sclerosis (FSGS). Two had changes classified as nephrosclerosis, but with an autosomal dominant mode of inheritance. Finnish type congenital nephrotic syndrome was present in two children and familial amyloidosis in two adults. Two patients had an unclassified disease. During follow-up, five patients with cystic/dysplastic disorders manifested liver disease. None of the patients with FSGS had recurrence and none of the Alport patients had anti-GBM disease. There were no other complications related to the renal condition. In conclusion, hereditary disorders are underestimated in regular registries of patients with end-stage renal failure. An adult form of FSGS and what seems to be a hereditary form of nephrosclerosis are among those that merit further study.

Adolescent↗

Physical performance does not improve in elderly patients following successful kidney transplantation.

In a prospective study before, and during 1 year following, kidney transplantation, physical strength and performance were tested in patients over the age of 60 and in younger control patients. Quadriceps strength increased significantly in the control patients (+3.3 +/- 3.2 kg, n = 11, P = 0.007) but remained stable in the successfully grafted elderly patients (-0.1 +/- 4.2 kg, n = 16). Grip strength tended to increase in the control patients (P = 0.064) but not in the elderly. Stepping up on a chair--a test of strength and coordination in combination--could be performed by all control patients on all occasions. Fourteen of 16 elderly patients managed it before transplant, but only 3/12 after 3 weeks, 5/13 after 6 months, and 10/16 after 1 year. Forced expiratory volume during 1 s and working capacity on the ergometer bicycle also tended to decline during 1 year. We conclude that the average elderly person does not gain strength during 1 year after successful kidney transplantation.

Adolescent↗

Outcome of renal transplantation in patients over the age of 60: a case-control study.

The outcome of kidney transplantation in 70 consecutive patients aged 60 years or more was compared to that of matched contemporary controls aged 18-54 years. Although the elderly patients were a positive selection from a much larger population in dialysis their first-year mortality was significantly increased (8 versus one of the controls, P = 0.016). Morbidity in bronchopneumonia was also increased (11 versus 2, P = 0.009). In the group of elderly patients six grafts were lost due to the death of the patient. Neither the rate of irreversible rejection nor the need for extra antirejection therapy differed between the groups. The increased mortality and morbidity suggest that the selection had not been too restricted. Thus kidney transplantation should only be offered to a minority of elderly uraemic patients.

Adolescent↗

Reversed-phase high-performance liquid chromatography for the determination of haemorphin-like immunoreactivity in human cerebrospinal fluid.

The haemorphins are opioid peptides derived form the blood protein haemoglobin. This study was focused on the detection and determination of haemorphin-like immunoreactivity in human cerebrospinal fluid (CSF) by reversed-phase HPLC. For this purpose a SMART System, optimized for micropurification, was applied. Prior to application to HPLC, the peptide fraction of the CSF sample was extracted using a reversed-phase silica gel cartridge (Sep-Pak C18). In the HPLC separation, the peptide-like material associated with haemorphin-7 immunoreactivity was recovered and determined using a UV detector. The tryptophan residue present in the haemorphin sequence allowed UV detection at wavelengths (e.g., 276 nm) where interference with other co-eluting peptides lacking this residue is minimized. Recorded levels of haemorphin-like immunoreactivity were compared with those detected by radioimmunoassay.

Amino Acid Sequence↗

Long-term renal allograft function.

Long-term function of transplanted kidneys was measured as 51Cr EDTA clearance (GFR). All kidneys transplanted in 1985 with preserved function after 6 months were again studied after 12, 24, 36, and 60 months. Grafts lost due to the patient's death were excluded. There was no significant GFR difference at 6 months between grafts with continued function (median 42 ml/min, range 15-79 ml/min; n = 69) and those that failed later (median 39 ml/min, range 20-87 ml/min; n = 18). Median GFR of surviving grafts remained stable, but individual variations included reductions by 5-49 ml in 29 patients and increases by 5-33 ml in 22 patients. Nine of the failing grafts showed a continuous but rarely linear decline, while eight had initially increased GFR. The long-term GFR changes were not statistically correlated with the dosage of cyclosporin at 6 months or with later dose reductions. In conclusion, renal transplant function may deteriorate in the long-term but can also improve.

Adolescent↗

Clinical evaluation in organ transplant patients of a polymerase chain reaction test for CMV DNA applied on white blood cells and serum.

A polymerase chain reaction (PCR) test for CMV DNA was evaluated for clinical usefulness. Leukocytes and serum were sampled from 36 patients who had recently undergone organ transplantation. Clinical symptoms, virus culture, and IgG and IgM antibodies were used to identify, in retrospect, patients with CMV disease certified beyond all doubt, with probable disease, with asymptomatic infection, or without infection. PCR tests for CMV DNA in leukocytes (BC-PCR) and serum (SE-PCR) were then evaluated. BC-PCR was positive in all patients with certified CMV disease but also in 31% of the samples from patients without infection. SE-PCR was positive in 11/13 patients with certified disease and was concordant with CMV culture in 192/231 tests. Of the 39 discordant cases, 27 had a positive SE-PCR with a negative culture. The effect of ganciclovir treatment could not be predicted by any test. In conclusion, a negative BC-PCR is strong evidence against CMV disease and a positive SE-PCR strongly suggests CMV disease, but the opposite results are of little clinical help.

Adult↗

A long-term cross-over pharmacokinetic study comparing perphenazine decanoate and haloperidol decanoate in schizophrenic patients.

The purpose of the study was to investigate clinical and pharmacokinetic parameters concerning perphenazine decanoate (PD) and haloperidol decanoate (HD) with an interval of 3 weeks during a study period of 51 weeks. This was done by using the available drug preparations in chronic schizophrenic patients in a randomised, double-blind, cross-over, multicentre study. In addition, an elimination phase of 6 weeks was added, when no IM injections of the depot drugs were given. Twenty-nine patients in a stable neuroleptic maintenance phase entered the study. The patients were rated during the trial according to the CPRS-SCHZ and CGI scales, the UKU side effect scale and serum concentrations of the drugs and prolactin were monitored. There was no significant difference between the drugs in antipsychotic efficacy or side effects. Thus, the doses were equipotent with regard to the CPRS-SCHZ scores. However, the patients' global improvement rating was higher for PD (52%) than for HD (39%) (P > 0.05). The elimination of both drugs was very slow. No interaction effects between PD and HD were observed. The serum levels of HD were in most patients lower than those recommended for acute-subacute treatment. The mean doses were 117 mg (0.29 mmol), range 20-313 mg PD and 120 mg (0.32 mmol), range 20-350 mg HD. The serum concentrations in nmol/L of perphenazine and haloperidol (week 24) were 0.8-15.9 and 2.3-46.7, respectively.

Adult↗

Characterization of the anti-A antibody binding in an ABO-incompatible living donor renal transplantation.

A 57-year-old female, blood group B, with polycystic kidney disease, received an ABO-identical, HLA-A,B,DR 5-mismatched renal allograft in 1986. Due to graft artery thrombosis and vascular rejection, she lost the kidney 6 months after transplantation and developed HLA antibodies with a panel reactivity of 99%. Despite 5 years on a European waiting list for highly immunized patients, she was not offered a second kidney. An attempt to remove her HLA antibodies by plasmapheresis combined with cyclophosphamide therapy did not succeed. Her 53-year-old HLA-identical, but ABO-incompatible sister (blood group A1), was then accepted as a donor. After immunoadsorption on Biosynsorb-A columns, transplantation was performed. The post-transplant course was uneventful without any signs of rejection. Studies on the anti-A antibody binding characteristics before and after immunoadsorption and after transplantation, showed that IgM and IgG antibodies recognizing the A trisaccharide epitope based on the type 1, 2, and 4 core saccharide chains, were effectively removed by Biosynsorb-A adsorption, but the column failed to remove anti-A antibodies recognizing the A type 3 antigen. These antibodies probably requires part of the core saccharide chain for binding. The presence of these antibodies did not seem to influence the outcome of the ABO-incompatible transplantation.

ABO Blood-Group System↗

Early renal graft function in recipients treated with the calcium channel blocker felodipine.

Calcium channel blocking agents (CCB) differ in molecular structure and effects. Each must therefore be evaluated separately. Out of 139 patients who received cadaveric kidney transplants between March 1990 and December 1991 22 were treated with the CCB agent felodipine as antihypertensive therapy on admission and post transplant. The early function of their grafts was compared with that of grafts to patients not treated with any CCB agent pre or post transplant (n = 38). There were no other significant differences in patient or donor characteristics. In the felodipine treated group, 18/22 showed immediate onset of graft function vs 20/38 in the non CCB group (p = 0.02). Dialysis post transplant was required by one felodipine-treated patient vs 12 in the non CCB group. Serum creatinine on day 7 was lower in felodipine treated patients, median 155 vs 259 mumol/l. Felodipine treatment did not seem to cause any significant interaction with cyclosporin A (CyA). The frequency and severity of acute rejection did not differ between the groups.

Adolescent↗

[Terminal kidney failure, uremia care and kidney transplantation].

In the Nordic countries, the annual figures for new patients scheduled for renal replacement therapy (i.e., dialysis or kidney transplantation) are 49 (Denmark), 55 (Finland), 65 (Norway) and 99 (Sweden) per million of the population (pmp). Some 40-50 of those patients are medically eligible for transplantation. If the transplant rate of the individual transplant centre or country is less, the waiting list will increase, as they do at some of the Nordic centres. The annual rate of transplants from living related donors, including spouses, varies from almost zero in Finland to nearly 20 pmp in Norway. The average age of recipients has increased with the increasing age of patients accepted for dialysis. Of the Nordic countries, Norway has the highest acceptance rate of patients above the age of 70, whereas dialysis is the preferred treatment for most of the elderly patients in the other Nordic countries. During the period 1989-93, death with a functioning kidney accounted for nearly half the graft losses in the Norwegian transplant population, and graft rejection for 37 percent. Cardiovascular disease was a predominant cause of death.

Adult↗