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Biomedical subjects

G Nyberg

Publications and source records attributed to G Nyberg.

At least 55 records · Page 3Linked to original sources
PubMed1997

Glomerular volume and the glomerular vascular pole area in patients with insulin-dependent diabetes mellitus.

The vascular pole area (VPA) and glomerular volume were measured in renal biopsies from 9 insulin-dependent diabetes mellitus (IDDM) patients with normal albumin excretion rate (IDDM group 1), 38 IDDM patients with albumin excretion rate > 15 micrograms/min (IDDM group 2) and 10 living kidney donors (ND). The volume of individual glomeruli was estimated as the sum of profile areas factored by the measured distance between levels, t approximately 10 microns, and VPA as the sum of chords multiplied by t. Mean glomerular volume was increased in IDDM patients but reached statistical significance only in IDDM group 2 (P = 0.002 vs ND). VPA was significantly different among the groups, mean (CV%) was 2036 (29) microns2 in ND, 3555 (34) micron2 in IDDM group 1, and 3528 (48) microns2 in IDDM group 2, p = 0.004 and 0.001, IDDM versus ND. VPA calculated as a percentage of the surface area of the corresponding glomerulus was 2.4 (23)% in ND, 3.4 (27)% in IDDM group 1, and 3.3 (42)% in IDDM group 2; P = 0.007 and 0.01, IDDM versus ND. The intra-biopsy coefficient of variation was high (20-35%) and of the same order in all groups for all three measurements. Glomerular volume and absolute as well as relative size of VPA showed a positive correlation with estimates of mesangial expansion in IDDM group 2 and the VPA showed a negative correlation with GFR. Thus, part of the enlargement may represent a compensatory phenomenon triggered by the development of structural and functional abnormalities in the diabetic kidney.

Adolescent↗
PubMed1997

Rejection rates in kidney transplant patients with and without IgA nephropathy.

BACKGROUND: Based on graft survival rates it has been claimed that patients with IgA nephropathy have a reduced risk of rejection after kidney transplantation. We wanted to evaluate this hypothesis. METHODS: Certified IgA nephropathy was the original disease in 70 of 874 consecutive kidney transplant patients (8.0%). Eighty per cent of the patients were men. Median age was 37 years, range 9-64. Fifty-three per cent had living donors and 20% of the transplantations were pre-emptive. Non-diabetic patients matched for age, sex, type of donor, and transplant number served as controls. Median follow-up time was 68 months. Duration of treatment for rejection during the first year post-transplant and graft loss due to rejection was recorded. RESULTS: The fraction of patients treated for rejection during the first year was 53% versus 54% of controls and the number of days when any antirejection treatment was given was 5.0 +/- 7.5 versus 5.5 +/- 7.4. Actual 3-year graft survival was 81% versus 80% and the number of grafts lost due to rejection was 9 versus 11. CONCLUSIONS: Rejection rates were not reduced in patients with IgA nephropathy and survival of grafts and patients not better than for matched controls.

Adolescent↗
PubMed1997

Gender differences in a kidney transplant population.

The purpose of this study was to compare female and male kidney transplant recipients. Of 1095 consecutive kidney transplants, 63.7% were to male recipients. Detailed demographic background data and follow-up data were used in the analysis. Female and male recipients were the same age, median 44, range 1-71 years. The male/female ratio was increased in all adult age groups, and most pronounced in the middle-aged. The proportions of first transplants and of preemptive transplants were not different, and 22.0% of men compared with 24.4% of women had living donors. Biopsy-verified chronic glomerulonephritis was found 2.4 times more often in men than in women, unknown diagnosis including non-biopsy-verified chronic glomerulonephritis 2.3 times, and adult dominant polycystic kidney disease 1.8 times. A larger proportion of men than women received antirejection treatment, 59.5% vs 49.5% (P = 0.002). Cumulative survival of patients or grafts was not different, but women > or = 50 years of age tended to have poorer 1-year graft survival than men, 69% vs 78% (P = 0.06). It is concluded that the increased proportion of men in our transplant programme is mainly due to their higher requirement of renal replacement therapy.

Adolescent↗
PubMed1997

Autosomal dominant polycystic kidney disease in a kidney transplant population.

AIM: To define specific manifestations of autosomal dominant polycystic kidney disease in kidney transplant patients. METHODS: Of 874 consecutive first renal transplant patients 1985-1993, 114 (13%) had autosomal dominant polycystic kidney disease (ADPKD). Mean age was 53 +/- 8 years, 62% were men, and 83% received cadaveric kidneys. Control patients were matched for sex, age and donor type. Median follow-up time was 63 months. One patient was lost to follow-up. Medical records before and after transplantation were reviewed. RESULTS: Survival of patients and grafts was similar in ADPKD patients and controls. Twenty-five ADPKD patients died, four of causes not seen in the controls; two aortic aneurysms, one urothelial cancer, one colon perforation. Four more ADPKD patients but no control had diverticulitis (P = 0.03), two with perforation. Cardiovascular morbidity was not increased. Eight patients had subarachnoidal haemorrhage before transplantation and two during follow-up. Nineteen patients had undergone nephrectomy before transplantation, 11 because of voluminous kidneys, five for infection, pain or bleeding, two for suspected malignancy, one for hypertension. After transplantation, seven patients underwent nephrectomy, only one related to kidney size. During the first year, need of phlebotomy occurred in 14% of patients versus 4% of controls, P = 0.02. Urinary tract infection rates were not increased. No morbidity was related to liver cysts. CONCLUSION: The specific features of kidney transplantation to patients with ADPKD were few: enlarged kidneys, relevant only before transplantation, erythrocytosis, and as rare but serious events, diverticulitis with perforation.

Adult↗
PubMed1997

Predictors of renal morphological changes in the early stage of microalbuminuria in adolescents with IDDM.

OBJECTIVE: To evaluate the impact of glycemic control, blood pressure, lipid levels, glomerular filtration rate (GFR), age, and duration of IDDM on the degree of structural glomerular changes in the transitional stage of microalbuminuria. RESEARCH DESIGN AND METHODS: Fifteen adolescents (seven boys and eight girls) with > 5 years of duration of IDDM and with low-grade microalbuminuria (15-30 micrograms/min) participated. Seventeen living kidney donors served as healthy control subjects. Five-year mean HbA1c; 5-year mean systolic and diastolic blood pressure; GFR, cholesterol, and triglycerides 2-5 years before renal biopsy; age; and duration of IDDM were investigated and related to basement membrane thickness (BMT), mesangial and matrix volume fractions, and the overall glomerulopathy index [(BMT/10 + mat/glom, %) + matrix star volume]. RESULTS: BMT and the overall diabetic glomerulopathy were increased in diabetic patients as compared with control subjects (P < 0.001), whereas matrix volume fraction, but not mesangial volume fraction, tended to be increased (P = 0.11). In multivariate analysis, BMT was predicted by 5-year mean HbA1c, diabetes duration, and previous GFR (R2 = 0.71, P = 0.003). With matrix volume fraction as the dependent variable, BMT and diabetes duration were the only significant determinants (R2 = 0.63, P = 0.003). Diabetes duration, 5-year mean HbA1c, and GFR were the variables with an independent influence on the overall diabetic glomerulopathy index (R2 = 0.72, P = 0.003). Preceding blood pressure and lipid levels or age had no significant independent influence on these morphometric measures. CONCLUSIONS: In the very early stage of microalbuminuria in IDDM adolescents, a high percentage of the variation in BMT and overall severity of glomerulopathy is explained by prolonged hyperglycemia and diabetes duration. Previous glomerular hyperfiltration may also add to the prediction of these morphological changes.

Adolescent↗
PubMed1997

PET-methionine of skull base neuromas and meningiomas.

Eighteen patients with intracranial skull base tumours diagnosed at CT or MR as neuromas or meningiomas were studied with positron emission tomography (PET) using L-(methyl-11C) methionine. Compared with normal cerebellar tissue, the uptake of methionine in the tumours increased more rapidly and reached a higher level, and showed a slow decline after a peak occurring about 5 min after the injection. All the meningiomas exhibited considerably higher accumulation of the tracer compared with the surrounding cerebellar tissue, which made the tumour easy to identify and to demarcate from the surrounding cerebellar tissue, which made the tumour easy to identify and to demarcate from the surrounding structures (tumour to cerebellum ratios 2.62-5.37, mean 3.63). The uptake was homogeneous in all meningiomas, which were all of the syncytial type. The neuromas showed lower contrast against the cerebellum (tumour to cerebellum ratios 1.1-1.87, mean 1.48). Some neuromas displayed an irregular pattern with regions of decreased tracer uptake corresponding to small cystic areas within the neuroma. There was no overlap in methionine uptake between the two tumour groups. The results indicate that PET-methionine may contribute to the evaluation, treatment planning and follow-up of patients with skull base meningiomas and neuromas.

Adult↗
PubMed1997

Evaluation of quality of life and symptoms after translabyrinthine acoustic neuroma surgery.

OBJECTIVE: This study aimed to describe the consequences of acoustic neuroma surgery in terms of symptoms and quality of life. STUDY DESIGN: This study was a retrospective case review. SETTING: The surgery was conducted in Uppsala, Sweden. PATIENTS: A consecutive sample of acoustic neuroma patients operated on between 1988 and 1994. INTERVENTION: All patients had been operated on with the translabyrinthine technique. MAIN OUTCOME MEASURES: A questionnaire was constructed including questions about the surgery and symptoms. The House and Brackmann scale was used for grading facial function and the Brackmann and Bars scale was used for self-assessment of facial function. RESULTS: Follow-up data were collected by a postal questionnaire sent out and returned by 141 patients, which yielded a 90% response rate. Normal to moderately impaired facial function (House I-III) was evident in 85.2% of patients, although residual facial problems were reported. Most considered hearing to be worse after surgery (80%), and tinnitus was found in 60% of the sample. Balance problems (45%), dizziness (19%), and headache/pain (22%) were also reported. Work ability was affected in 23%, and 37% reported a continued need for medical consultations, mainly because of facial problems and pain. Most (89%) were pleased with the preoperative information. CONCLUSIONS: This study showed that few patients with acoustic neuroma had experienced negative social consequences after surgery. Although not linked to the operation, residual symptoms were reported that may necessitate further rehabilitation.

Adult↗
PubMed1996

Isolation of haemorphin-related peptides from filter membranes collected in connection with haemofiltration of human subjects.

This paper describes the extraction and isolation from dialysis filters of two peptides containing the opioid active sequence haemorphin-7. The filter devices were obtained from uraemic patients subjected to haemofiltration. Following acidic extraction of the filter membranes the peptides were purified by size-exclusion, ion-exchange chromatography and finally by reversed-phase chromatography using different columns and different chromatographic systems. The purification was guided by radioimmunoassay and the structure of the final products was elucidated by N-terminal sequencing and fast-atom bombardment mass spectrometry as well as micro-electrospray mass spectrometry. The isolated peptides were suggested to be identical to fragments 1-41 and 32-41 of the beta-chain of human haemoglobin.

Amino Acid Sequence↗
PubMed1996

Kidney transplantation to patients with congenital malformations of the distal urinary tract.

Fourteen of 1000 consecutive kidney transplant patients had congenital malformations affecting the bladder or urethra: six had congenital valvulus of the urethra, two congenital sclerosis of the bladder outlet, and six a neurogenic bladder. Pretransplant surgery had been performed in all patients: reimplantation of ureter (n = 11), resection of congenital valvulus (n = 7), and nephrectomy (n = 6). Four patients had an intestinal bladder. Age was 0-17 (median 1) years at diagnosis. Follow-up time was 3-10 (median 5) years. Special transplant surgery techniques were required in five patients. Patient survival after 2 years was 100% and graft survival 93%. No graft was lost due to outflow obstruction, infection or other causes related to the underlying disorder. Late technical problems were seen in two patients. Urinary tract infections were reported in 13 patients before transplantation and in eight after. Results of transplantation were excellent. Infections and surgical problems had a minor impact on outcome.

Adolescent↗
PubMed1996

Activation PET scanning in pretreatment evaluation of patients with cerebral tumours or vascular lesions in or close to the sensorimotor cortex.

Treatment of tumours and vascular lesions in or close to eloquent cortex may inflict neurological deficits. Intra-operative mapping procedures have been used for many decades in efforts to minimize neurological sequelae. The possibility for non-invasive pre-operative brain mapping has emerged with the advent of positron emission tomography (PET). In this paper we report on 11 patients with a tumour or vascular lesion in or close to the sensorimotor (10 patients) or visual cortex (one patient). The patients were subjected to activation PET scanning by means of vibrotactile or visual stimulation. The results show that in most of the patients the important relation between the lesion and the sensorimotor cortex could be determined. The patient with a lesion in the occipital lobe had involvement of the entire visual cortex as judged by comparison with activated areas on the nonlesion side.

Adult↗
PubMed1996

Concentration-related pharmacodynamic effects of thioridazine and its metabolites in humans.

OBJECTIVE: To measure cardiac and other effects of thioridazine and relate these to the plasma concentration of the parent drug and its principal metabolites. METHODS: A double-blind, randomized-order crossover study involving nine healthy male subjects compared the effects of single doses of thioridazine (10 mg and 50 mg) with placebo. Plasma concentrations of thioridazine and its ring sulfoxide, side-chain sulfoxide, and side-chain sulfone metabolites were measured, together with effects on the ECG, blood pressure, salivary flow, and a batch of psychomotor tests for 72 hours after administration. RESULTS: Thioridazine, 50 mg, reduced standing systolic blood pressure (mean peak changes from baseline [95% CI] -32 mm Hg [-55, 10 mm Hg]; p < 0.01 versus placebo) and diastolic blood pressure (-14 mm Hg [-26, -2 mm Hg]; p < 0.05), increased standing heart rate (7 beats/min [-1, 16 beats/min]; p < 0.05), impaired psychomotor function, and prolonged the JT (20 ms1/2 [7, 34 ms1/2]; p < 0.05), QTa (22 ms1/2 [8, 36 ms1/2]; p < 0.05), and QTc (22 ms1/2 [11, 33 ms1/2]; p < 0.01) intervals, but had no effect on QT dispersion (-12 ms1/2 [-31, 6 ms1/2]). Thioridazine, 1.0 mg, also significantly increased QTc, but the effect was less marked (9 ms1/2 [-1, 19 ms1/2]; p < 0.05). Plasma thioridazine and metabolite concentrations did not correlate significantly with these effects. Maximum effects on QTc occurred after peak concentrations of thioridazine but before peak concentrations of the ring sulfoxide and side-chain sulfone metabolites. CONCLUSIONS: These data suggest that thioridazine has dose-related effects on ventricular repolarization and that the parent drug causes an important proportion of these effects, although its metabolites may also contribute.

Adult↗
PubMed1996

Type 2 diabetic patients with nephropathy in a Scandinavian kidney-transplant population.

Twenty-seven patients in a cohort of 1000 who received kidney transplants in Göteborg 1985-1993 were found to have diabetes of Type 2 as primary cause of renal failure. All took insulin at the time of transplantation. Four received concomitant pancreas transplants. Mean age was 53 years (range 40-64). All but four were men. Average waiting time on dialysis was less than a year. One year after transplantation 24 of 27 (89%) were alive, 22 (81%) with functioning grafts. However, during follow-up for a total of 51 +/- 27 months 9 (33%) of the diabetic patients died, mainly of cardiac disease or sudden death (n = 7), compared with 17% of matched controls (NS). Diabetic patients had an increased risk of death with a functioning graft, 6/27 versus 3/54 controls (p = 0.02). Graft survival rates were 56% and 65%, respectively (NS). Morbidity was dominated by cardiovascular events and foot ulcers leading to amputations (six patients) and septicaemia. During follow-up body mass index increased from 24.6 +/- 3.0 to 25.9 +/- 3.4 kg/m2. There was no difference in HbA1c-values although one pancreas-transplanted patient remained insulin-independent. The mortality and morbidity rates in this positive selection from a much larger population of Type 2 diabetic patients supports continued restriction in the acceptance rate for transplantation. Type 2 diabetes is not an indication for pancreas transplantation, which is one reason to distinguish this form of diabetes.

Adult↗
PubMed1996

Glomerular ultrastructure in kidneys transplanted simultaneously with a segmental pancreas to patients with type 1 diabetes.

BACKGROUND: Pancreas transplantation has been reported to prevent development and progression of diabetic glomerulopathy. STUDY DESIGN: Kidneys transplanted to type 1 diabetic patients were investigated for signs of diabetic glomerulopathy. Biopsies were obtained from 11 patients 2-4 years after simultaneous pancreas and kidney transplantation and from six patients 2-6 years after kidney transplantation alone. During follow-up, glycaemic control was monitored as glycated haemoglobin and, in the pancreas transplant patients, as i.v. glucose tolerance. RESULTS: Measures of glycaemic control were consistently normal in only two pancreas transplant patients. Four had mean k values <1.0. In kidney biopsies from the pancreas transplant patients, thickness of the glomerular basement membrane was 395 (0.13) nm (mean, coefficient of variation), which is higher than normal (324 (0.13) nm, P=0.01) and not different from diabetic patients with kidney transplants alone, 418 (0.15) nm. The mean calculated annual increase in thickness did not differ between patients with and without a pancreas transplant, 26 (0.77) versus 29 (0.54) nm/year. Estimates of the mesangium and mesangial matrix were in the normal range in both groups while the interstitial volume fraction was increased and to a similar extent. CONCLUSION: The increase in thickness of the glomerular basement membrane in kidneys transplanted simultaneously with a segmental pancreas is probably an expression of diabetic glomerulopathy caused by the modest impairment in glucose metabolism present in most patients.

Adult↗
PubMed1996

Reduced left ventricular hypertrophy in type 1 diabetic patients with end-stage renal failure. A comparison between groups investigated 1977-80 and 1991-93.

BACKGROUND: During the last decade, control of hypertension, oedema, anaemia, uraemia, and blood glucose has improved in patients with diabetic nephropathy. We have investigated whether this has influenced cardiac function at the time of end-stage renal failure. STUDY DESIGN: Echocardiographic investigations were performed in 26 type 1 diabetic patients evaluated for kidney transplantation and the results compared with those obtained in healthy controls and in a similar group of patients investigated in 1977-1980. RESULTS: Blood pressure was 153 +/- 21/85 +/- 12 mmHg versus 174 +/- 17/91 +/- 9 (recent group versus early group). The left ventricular (LV) diameter index, a measure of volaemia, was increased in systole and diastole in the early but not in the recent group. Both groups had LV hypertrophy, but this was much less pronounced in the recent group; posterior wall thickness was 1.1 +/- 0.16 cm versus 1.3 +/- 0.26 cm (P = 0.0001) and LV mass index 132 +/- 43 g/m2 versus 166 +/- 44 g/m2 (P = 0.009). Blood pressure correlated significantly with indices of LV hypertrophy in the recent group. Systolic function was normal in both groups but diastolic function was disturbed in both and to the same extent, atrial systole contributing by 27 +/- 14% to ventricular filling. CONCLUSION: Better treatment of hypertension, fluid overload, and uraemia has led to less pronounced LV hypertrophy. The remaining correlation with blood pressure suggests that more could be gained by intensified antihypertensive treatment.

Adult↗