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Biomedical subjects

J Mustonen

Publications and source records attributed to J Mustonen.

At least 73 records · Page 4Linked to original sources
PubMed1995

Albumin excretion rate and its relation to kidney disease in non-insulin-dependent diabetes mellitus.

OBJECTIVE: To estimate the occurrence of increased albumin excretion rate (AER) and its significance as a marker of diabetic kidney disease in non-insulin-dependent diabetic subjects. DESIGN: Population-based, controlled cross-sectional study. SETTING: A primary health care centre in the city of Tampere, south-west Finland. SUBJECTS: Consecutive, recently diagnosed (n = 150) and long-term (n = 146) middle-aged non-insulin-dependent diabetic subjects. Matched non-diabetic control subjects (n = 150). MAIN OUTCOME MEASURES: Albumin excretion rate, fractional AER, microalbuminuria (AER 30-300 mg 24 h-1), clinical nephropathy (AER exceeding 300 mg 24 h-1) and kidney biopsy in diabetic subjects with an AER exceeding 100 mg 24 h-1. RESULTS: Mean (+/- standard deviation [SD]) 24-h AER was increased in recently diagnosed diabetic subjects, 54 (111) mg, and long-term diabetic subjects, 134 (479) mg, compared to non-diabetic control subjects, 16 (19) mg. The fractional AER was 7.5 (18.3) x 10(-6) in recent diabetic subjects, 53.1 (306.9) x 10(-6) in long-term diabetic subjects and 2.8 (3.7) x 10(-6) in non-diabetic control subjects. Microalbuminuria was found in 8% of non-diabetic subjects, in 29% of recent and in 27% of long-term diabetic subjects. The prevalence of clinical nephropathy was 7% in long-term and 4% in recent diabetic subjects, whilst no non-diabetic subject had nephropathy. In 12 of 16 eligible kidney biopsies, diabetic glomerulosclerosis was found, in four subjects the finding was normal. CONCLUSIONS: The AER is clearly increased in recent non-insulin-dependent diabetic subjects and further increased in diabetic subjects with a mean disease duration of 10 years. An increased AER in non-insulin-dependent diabetic subjects suggests diabetic kidney disease.

Adult↗
PubMed1995

Myocardial sympathetic nervous dysfunction detected with iodine-123-MIBG is associated with low heart rate variability after myocardial infarction.

UNLABELLED: The association between myocardial sympathetic innervation and heart rate variability after myocardial infarction was studied in a group of 12 men (aged 30-65 yr) 3 mo after their first myocardial infarction. METHODS: Viable myocardium was imaged using 123I-phenylpentadecanoic acid (pPPA). Functioning myocardial sympathetic nervous tissue was imaged using [123I]-metaiodobenzylguanidine (MIBG). Heart rate variability was measured as the ratio of maximum-to-minimum RR intervals in ECG during deep breathing. RESULTS: The patients were divided into normal (n = 6) and low (n = 6) heart rate variability groups. Myocardial infarction size (pPPA defect) was comparable in the normal and low heart rate variability groups. Even the MIBG defect size was not significantly different in the normal and low groups, the portion of viable myocardium with impaired sympathetic innervation (MIBG defect minus pPPA defect) was significantly greater in the low heart rate variability group than in the normal group. CONCLUSION: The extent of viable myocardium with disturbed sympathetic innervation was greater in patients with low heart rate variability as compared to those with normal heart rate variability 3 mo after myocardial infarction.

3-Iodobenzylguanidine↗
PubMed1995

Isolated microscopic hematuria in patients with rheumatoid arthritis compared with age and sex matched controls. A population based study.

OBJECTIVE: To evaluate the prevalence and causes of isolated microscopic hematuria in patients with rheumatoid arthritis (RA). METHODS: An unselected population of 1018 patients with RA (810 women, 208 men) were studied prospectively (n = 604) or retrospectively (n = 414), and the results were compared with an age and sex matched control population (n = 457; 352 women, 105 men). Hematuria was defined as a positive dipstick result in 2 urine samples, and was regarded as isolated when no concomitant proteinuria was found (urine protein excretion < or = 0.15 g/24 h). To investigate the urological causes of isolated hematuria, urine cytology, renal ultrasound, and urethrocystoscopy were undertaken. Renal biopsy was performed when no urological lesions were found. RESULTS: There was no difference in the prevalence of isolated hematuria between patients with RA and controls (women 10 and 9%, men 5 and 6%, respectively; total 9% for both). Mild mesangial glomerulopathy was the most common renal biopsy finding in patients with RA with isolated hematuria, found in 13 of 15 adequate renal biopsy specimens. The cause of hematuria remained uncertain or unknown in 52% of the patients with RA and in 61% of controls. CONCLUSION: The prevalence of isolated microscopic hematuria was not significantly more frequent in patients with RA than in age and sex matched controls. This result was independent of the definition or grade of hematuria. Mesangial glomerulopathy was the most common renal biopsy finding in patients with RA with isolated hematuria.

Adult↗
PubMed1994

Modelling contrast sensitivity as a function of retinal illuminance and grating area.

We extended the contrast detection model of human vision [Rovamo, Luntinen & Näsänen (1993b) Vision Research, 33, 2773-2788] to low light levels by taking into account the effect of light-dependent quantal noise. The extended model comprises (i) low-pass filtering due to the optical modulation transfer function of the eye, (ii) addition of light-dependent noise at the event of quantal absorption, (iii) high-pass filtering of neural origin (lateral inhibition), (iv) addition of internal neural noise, and (v) detection by a local matched filter whose efficiency decreases with increasing grating area. To test the model we measured foveal contrast sensitivity as a function of retinal illuminance and grating area at spatial frequencies of 0.125-32 c/deg. In agreement with the model, monocular contrast sensitivity at all grating areas increased in proportion to I when retinal illuminance (I) was smaller than critical illuminance. Thereafter the increase saturated and contrast sensitivity became independent of retinal illuminance. Similarly, at all levels of retinal illuminance contrast sensitivity increased in proportion to A when grating area (A) was smaller than critical area. Thereafter the increase saturated and contrast sensitivity became independent of area. Critical level of retinal illuminance increased in proportion to the spatial frequency squared. Critical area marking the saturation of spatial integration was constant at low spatial frequencies but decreased in inverse proportion to spatial frequency squared at medium and high spatial frequencies. The maximum contrast sensitivity obtainable by spatial integration in bright light increased at low spatial frequencies in proportion to spatial frequency, was constant at medium spatial frequencies, and decreased in inverse proportion to spatial frequency cubed at high spatial frequencies. The increase was due to the neural modulation transfer function of the visual pathways whereas the decrease was due to the optical modulation transfer function of the eye. The model explained 91-99% of the total variance of our contrast sensitivity data at various spatial frequencies.

Adult↗
PubMed1994

Two simple psychophysical methods for determining the optical modulation transfer function of the human eye.

The foveal optical modulation transfer function (OMTF) of the human eye for a pupil 8 mm in diameter was determined at 1-23 c/deg by using two new methods. The first method was based on the comparison of the effects of quantal and added spatial noise on grating contrast sensitivity at each spatial frequency. The rationale behind the comparison is the fact that quantal noise is not affected by the OMTF of the human eye, because individual quanta cannot be blurred by the point spread function of ocular optics. In the second method we measured spatial contrast sensitivity for gratings whose area decreased but illuminance increased in proportion to spatial frequency squared. For such gratings the variation of contrast sensitivity with spatial frequency (f > or = 0.5 c/deg) is solely due to the OMTF of the human eye, because the effects of grating area and retinal illuminance (quantal noise) on contrast sensitivity are independent of spatial frequency. The two methods provided identical OMTFs. The foveal optical modulation transfer function of the human eye for an 8 mm pupil was found to be OMTF = [1 + (f/11.1)2.5]-1, where f refers to spatial frequency in c/deg. The equation means that the OMTF is constant at low spatial frequencies, becomes reduced to 50% at 11.1 c/deg and decreases thereafter with a slope of -2.5 when plotted in double logarithmic coordinates. At 1-16 c/deg our OMTF showed less image degradation than any foveal OMTF of the human eye for 6-8 mm pupils reported so far in the literature.

Adult↗
PubMed1994

Clinical picture of nephropathia epidemica in children.

The clinical picture of nephropathia epidemica (NE) among children is poorly understood. We made a retrospective analysis of 32 patients aged 4-15 years treated in hospital for serologically verified recent NE. The most common clinical findings were high fever (100%), nausea (81%), vomiting (72%), tenderness in the kidney area (63%), abdominal pains (59%) and headache (59%). A peculiar symptom of NE, transient visual abnormalities, was found in 25% of patients. Four children had clinical bleeding and 1 had encephalitis. 44% were transiently hypertensive. Renal function was impaired in 84%, proteinuria was present in 97%, hematuria in 73% and leukocyturia in 44%. Other common laboratory findings were thrombocytopenia (87%), leukocytosis (41%), elevated ERS (74%, up to 76 mm/h) and CRP level (89%, up to 97 mg/l), elevated liver enzymes (53%) and hypoalbuminemia (50%). No child needed dialysis therapy and all recovered. NE seems to be less severe in children than in adults.

Adolescent↗
PubMed1994

Nephropathia epidemica in Finland: a retrospective study of 126 cases.

A total of 126 (99 males, 27 females) serologically confirmed hospital-treated adult cases of nephropathia epidemica (NE) were studied. The initial diagnosis suggested by the referring physician was correct in only 28%. Some rare clinical manifestations of NE were observed; acute myopericarditis in 3 patients and encephalitis in 1. Pulmonary involvement due to vascular congestion was observed in 16% and liver involvement in 34% of the patients. Thrombocytopenia was present in 75%, leukocytosis in 50% and anemia in 50%. Erythrocyte sedimentation rate (ESR) was 2-108 (mean 38) mm/h and C-reactive protein (CRP) 0-126 (mean 52) mg/l. Proteinuria was observed in 94%, hematuria in 58% and pyuria in 28%. Electrolyte abnormalities (hyponatremia, hypokalemia, hypocalcemia, hyperphosphatemia) were all common but rarely serious. Serum lipid changes caused by the acute infection and renal failure included very low total and HDL-cholesterol as well as high triglyceride levels. Renal function was transiently impaired in 94% of the patients and 7 needed transient dialysis therapy. All recovered.

Adolescent↗
PubMed1994

Community-acquired pyelonephritis in adults: characteristics of E. coli isolates in bacteremic and non-bacteremic patients.

Escherichia coli strains isolated from the urine in 49 consecutive episodes of community-acquired pyelonephritis in adult women were characterized for adhesins and hemolysin production. The mean age of the patients was 56 years and 47% had at least 1 compromising condition. P fimbriae was found in 67% and hemolysin production in 35% of the strains; these figures were significantly (p < 0.001) higher than the corresponding figures (11% for each) among 287 strains isolated from stool of healthy adults (Siitonen A. J Infect Dis 1992; 166: 1058-1065). The prevalence of Non-P mannose-resistant adhesins and type 1C fimbriae was low (4 and 8%, respectively) and did not differ significantly from the corresponding prevalences (1 and 7%) in healthy adults. 74% fo the pyelonephritic (but only 22% of the stool) isolates had at least 1 of these 4 virulence factors (p < 0.001) and 37% and 7%, respectively, had at least 2 (p < 0.001). Nevertheless, the strains represented a wide variety of O:K serotypes without any indication of specially virulent clones. Of the 49 patients 15 had concomitant bacteremia, and in all except 2 compromised elderly patients the urinary and blood isolates were identical.

Adult↗
PubMed1994

Renal biopsy findings and clinicopathologic correlations in nephropathia epidemica.

A series of 126 adult patients with a serologically confirmed diagnosis of nephropathia epidemica (NE) were studied during the acute phase of the disease. In 86 cases, renal biopsy was performed. The severity of renal failure correlated slightly with blood inflammatory parameters and the degree of hematuria but not with the amount of proteinuria. The degree of hematuria correlated inversely with the level of thrombocytopenia. The most common histopathologic lesion was acute tubulointerstitial nephritis. Interstitial edema and inflammatory cell infiltrations were most usually present, followed by tubular epithelial and luminal alterations. Slight glomerular mesangial changes were present in 25% of the biopsy specimens. Except for hemorrhage in the outer renal medulla, the histologic lesions were relatively mild and unspecific. Interstitial hemorrhage should remind a pathologist of the possibility of NE. Tubular, interstitial and glomerular histologic damage were but vascular lesions were not associated with the clinical severity of renal failure. Glomerular alterations did not relate to the amount of urine protein excretion. Correlations, however, were so weak that in clinical work renal biopsy is usually not indicated for determination of the severity of renal failure in NE. Intrinsic renal events are probably important in the development of renal failure in NE.

Acute Kidney Injury↗
PubMed1993

Cross-reactivity between antibodies to thyroid microsomal antigens and myeloperoxidase.

Antibodies against thyroid microsomal antigen (thyroid peroxidase, TMA/TPO) and myeloperoxidase (MPO) were measured from 115 patients with vasculitic disorders and 144 patients with suspected thyroid disorders. Nineteen patients, three with vasculitis and 16 with thyroid disorders, were shown to have both TPO and MPO antibodies, suggesting cross-reactivity of these antibodies. Their cross-reactivity was further strengthened by studying the capacity of antibodies to tolerate dilution in enzyme immunoassay and reactivity with synthetic TPO/MPO peptides.

Antibody Specificity↗
PubMed1993

The effects of grating area and spatial frequency on contrast sensitivity as a function of light level.

Contrast sensitivity was measured as a function of retinal illuminance (I) for vertical cosine gratings of various circular areas (A) and spatial frequencies (f < or = 4 c/deg). Spatial frequency and grating diameter varied in inverse proportion to each other in order to keep the relative grating area (A x f2) constant at either 3.14, 12.6, 50.3, or 201 square cycles. At all grating areas and spatial frequencies contrast sensitivity in dim light first increased in proportion to the square root of retinal illuminance. Then the increase saturated and contrast sensitivity became independent of luminance level in bright light. For gratings with constant relative area contrast sensitivity functions were similar in shape and had the same maximum sensitivity but were shifted horizontally towards lower illuminances with decreasing spatial frequency. However, when replotted as a function of retinal illuminance divided by spatial frequency squared, contrast sensitivity functions fell on a common curve at all levels of relative retinal illuminance (I/f2).

Adult↗
PubMed1993

Abnormalities in left ventricular diastolic function in male patients with rheumatoid arthritis without clinically evident cardiovascular disease.

Epidemiological studies have suggested that patients with rheumatoid arthritis (RA) have increased mortality due to cardiovascular disease. We studied cardiac performance in 12 asymptomatic male patients with RA and 14 control subjects to elucidate early disturbances in cardiac function. In echocardiography, isovolumic relaxation time was longer (64 +/- 6 vs. 49 +/- 3 ms, mean +/- SEM, P = 0.010) and peak filling rate (134 +/- 10 vs. 159 +/- 6 mm s-1, P = 0.015) lower in patients with RA than in control subjects, reflecting an impairment in left ventricular diastolic function. Left ventricular systolic function assessed by radionuclide angiocardiography at rest and during exercise was similar in both groups. There were no differences between the patients with RA and control subjects in the heart rate, systolic blood pressure and oxygen uptake during peak exercise. Left ventricular diastolic function is impaired in spite of normal left ventricular systolic function in patients with RA without clinically evident cardiovascular disease and this may contribute to the excess of cardiovascular mortality in patients with RA.

Adult↗
PubMed1993

Metabolism of calcium and vitamin D3 in patients with acute tubulointerstitial nephritis: a study of 41 patients with nephropathia epidemica.

We studied serum concentrations of calcium, phosphate, intact parathyroid hormone (PTH) and vitamin D3 metabolites in 41 patients with nephropathia epidemica. Thirty-four of the 41 patients had a mild to moderate, mostly nonoliguric acute renal failure (ARF). Hypocalcemia developed in relation to the severity of renal failure, and parathyroid gland response to hypocalcemia was normal. The serum concentration of 1,25-dihydroxyvitamin D3 was lower than normal in patients who developed ARF. Serum phosphate was the most important factor in regulating the serum 1,25(OH)2D3 level, though only mild phosphate retention was seen in the patients. We observed normal or slightly elevated serum phosphate, hypocalcemia accompanied by elevated PTH levels and a decreased serum concentration of 1,25(OH)2D3 in patients with ARF caused by nephropathia epidemica.

Acute Kidney Injury↗
PubMed1992

Left ventricular function and dimensions in newly diagnosed non-insulin-dependent diabetes mellitus.

Left ventricular (LV) function and dimensions were assessed with Doppler and M-mode echocardiography in 26 men and 17 women with newly diagnosed non-insulin-dependent diabetes mellitus, and in 13 healthy control men and 13 women. The diabetic men had lower peak filling rate normalized to mitral stroke volume than the control men (mean +/- standard error of the mean, 4.2 +/- 0.1 vs 4.9 +/- 0.3 stroke volume/s, p less than 0.01). The diabetic women had increased LV mass (102 +/- 12 vs 86 +/- 8 g/m2, p less than 0.01) and decreased fractional shortening (34 +/- 1 vs 38 +/- 1%, p less than 0.05) when compared with control women. At 3 and 15 months, 23 diabetic men and 15 women were reexamined. Concomitantly with decreasing blood glucose levels, fractional shortening improved mainly during the first 3 months and was significantly higher in both diabetic men (36 +/- 2 vs 30 +/- 2%, p less than 0.05) and women (38 +/- 1 vs 34 +/- 1%, p less than 0.05) at 15 months than at baseline. In the diabetic men, peak filling rate increased from 4.3 +/- 0.1 stroke volume/s at baseline to 4.8 +/- 0.2 stroke volume/s at 15 months (p less than 0.05). At 15 months, peak filling rate was correlated (r = 0.61, p less than or equal to 0.001) with autonomic nervous function assessed as heart rate variability during deep breathing test in diabetic men who also showed an inverse correlation between LV hypertrophy and heart rate variability throughout the follow-up.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗