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Biomedical subjects

J Risteli

Publications and source records attributed to J Risteli.

At least 181 records · Page 10Linked to original sources
PubMed1992

Laminin and its neurite outgrowth-promoting domain in the brain in Alzheimer's disease and Down's syndrome patients.

Immunocytochemistry, radioimmunoassay, immunoblotting, Northern analysis, and polymerase chain reaction (PCR) technique were applied to investigate the distribution of laminin and its neurite outgrowth domain in brains of neuropathologically verified cases of Alzheimer's disease and Down's syndrome. New antibodies against a neurite outgrowth domain of laminin were characterized and were used in localization of this peptide antigen in the human brain. Laminin was found as large punctate deposits in all plaques in the affected brains. Laminin synthesis was increased as assessed by RNA blotting and immunoblotting, and glial cells were heavily immunoreactive with antibodies for a neurite outgrowth-promoting peptide antigen of the B2 chain of laminin. This peptide antigen not only was produced by glial cells but also was deposited in the brain tissue. As this peptide antigen promotes neurite outgrowth at low concentrations, and is specifically neurotoxic at high concentrations, it may play a synergistic role with other molecules in inducing the sprouting and neurodegeneration occurring in brains of patients with either Alzheimer's disease or Down's syndrome.

Adult↗
PubMed1992

Assessment of bone formation by biochemical markers in metabolic bone disease: separation between osteoblastic activity at the cell and tissue level.

In this study , serum levels of classical serum markers of bone formation [carboxyterminal propeptide of procollagen type I (S-PICP), bone Gla protein (S-BGP)], and total alkaline phosphatase (S-AP)) were related to the calcium kinetic index of whole skeletal mineralization rate (m) by regression analysis in a variety of metabolic bone diseases. For each disease, the regression coefficient (r) as well as the fraction: standard error of estimate/mean dependent variable (SEE/Y) were determined. In a group of 19 normals, only the regression of S-PICP on m reached significance (r = 0.53, P < 0.02, SEE/Y = 0.44), whereas regressions of S-AP and S-BGP on m were nonsignificant. In a pooled material of high- and low-turnover bone diseases without mineralization defects or spinal fracture [myxedema, thyrotoxicosis, and primary hyperparathyroidism (n = 48)], a highly significant positive regression of S-PICP on m was demonstrable (r = 0.50, SEE/Y = 0.63, P < 0.001). The regression coefficients obtained for S-BGP and S-AP were 0.74 (P < 0.001, SEE/Y = 0.41) and 0.42 (P < 0.01, SEE/Y = 0.55), respectively. When analyzing individual diseases in this group, significant differences among the three markers were detectable. In a group of 52 osteoporotics, S-PICP correlated significantly to m (r = 0.49, P < 0.001, SEE/Y = 0.50). Corresponding r-values for S-BGP and S-AP were 0.21 (NS) and 0.48 (P < 0.001, SEE/Y = 0.61), respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Effect of insulin on serum amino-terminal propeptide of type III procollagen in non-insulin-dependent diabetes mellitus.

The effect of insulin on the serum levels of the amino-terminal propeptide of type III procollagen (PIIINP) was investigated in patients with non-insulin-dependent diabetes mellitus, whose disease was unsatisfactorily controlled by oral drugs. Before insulin therapy the PIIINP values of the patients (3.2 +/- 1.3 micrograms/l, n = 38) varied within the range of healthy subjects (3.1 +/- 0.6 micrograms/l, n = 50, NS). Insulin therapy (6-20 IU at bedtime plus the oral drugs) improved the glycemic control and increased the serum PIIINP during a 4 week (3.1 +/- 0.9 to 3.8 +/- 1.1 micrograms/l, P less than 0.01, n = 8) and an 8 week period (3.2 +/- 1.3 to 3.8 +/- 1.6 micrograms/l, P less than 0.001, n = 22). The values were still elevated after 6 months on insulin (3.5 +/- 1.5 to 4.0 +/- 1.7 micrograms/l, P less than 0.01, n = 12). Placebo-insulin did not alter the concentration of PIIINP (3.1 +/- 0.6 to 2.8 +/- 0.6 micrograms/l, NS, n = 8) whereas the glycemic control improved and body weight decreased. The PIIINP values correlated with fasting insulin before (r = 0.403, P less than 0.05, n = 30) and after the therapy (r = 0.452, P less than 0.001, n = 60). Insulin therapy, while correcting the hormone deficiency and restoring glucose and protein metabolism, seems to activate the synthesis of type III procollagen in patients with NIDDM. This may promote the atherosclerotic process.

Adult↗
PubMed1992

Purification of porcine aminoterminal propeptide of type III procollagen from lymph and use for lymphatic clearance studies in pigs.

To investigate the lymphatic transport of the aminoterminal propeptide of type III procollagen (PIIINP) we established a thoracic duct-venous shunt in 6 pigs. Porcine PIIINP was purified, characterised, and compared with human PIIINP to ensure the suitability of the radioimmunoassay of human PIIINP for measurements in pigs. SDS-PAGE and radioimmunoinhibition assays show human and porcine PIIINP to be similar, thus indicating that the assay of human PIIINP is also reliable for determinations on pig serum and lymph. Intact PIIINP, as identified by gel filtration, accounted for 60% and 40% of the total PIIINP immunoreactivity in lymph and serum, respectively. The higher amount of total immunoreactivity and proportion of intact PIIINP in lymph compared with serum support the hypothesis that intact PIIINP is transported from peripheral tissue into the circulation by lymph. Two days after the shunt was established, the lymph was collected quantitatively hour-by-hour for 24 h. The flow was higher during the light periods than in the dark (p less than 0.01). The PIIINP concentration varied inversely with the flow, being higher in the dark hours (p less than 0.03). However, the total collected amount of PIIINP in lymph did not differ during the light and dark periods. Serum PIIINP remained unchanged over the 24 h. The lymphatic clearance of total PIIINP immunoreactive components was 6.2 ml serum/min and the lymphatic clearance of intact PIIINP was 9.1 ml serum/min, equal to 7 and 10 times the plasma volume/24 h, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Serum concentration of the cross-linked carboxyterminal telopeptide of type I collagen (ICTP) is a useful prognostic indicator in multiple myeloma.

Type I collagen is the main collagen type found in mineralised bone. Specific immunoassays for PICP (carboxyterminal propeptide of type I procollagen) and ICTP (cross-linked carboxyterminal telopeptide region of type I collagen) allow simultaneous assessment of the synthesis and degradation of type I collagen in serum samples, respectively. Our aim was to find out whether these metabolites of type I collagen are useful markers for following bone turnover and evaluating treatment response in multiple myeloma, which is a good model disease of excessive osteolysis. Fifteen consecutive patients were studied before and throughout their treatment. Samples for serum PICP and ICTP were collected before starting each treatment course of melphalan and prednisolon. Response to treatment was evaluated by following the changes in M protein and bone roentgenograms. The disease was progressing in four and regressive in 11 patients, but in four of these a recurrence occurred. In nonresponders the ICTP concentration was permanently elevated despite treatment. In responders both increased or normal levels of ICTP were initially observed, but they returned to or remained in the reference interval during treatment. The ICTP concentration increased upon recurring disease. There was a strong correlation between the extent of bone lesions and ICTP. There was no correlation between ICTP and PICP, the latter mainly remaining within the reference range, a finding that suggests no change in bone formation. ICTP was a significant predictor for survival in this patient group (P less than 0.05). We conclude that ICTP is a specific and sensitive marker for bone resorption. Simultaneous use of serum ICTP and PICP offers an additional and easy means to follow bone turnover and evaluate the response to therapy in multiple myeloma.

Biomarkers, Tumor↗
PubMed1992

Type III collagen metabolism in soft tissue sarcomas.

Sera of 85 patients with benign soft tissue lesions or sarcomas of soft tissues were investigated for a collagen metabolite, the aminoterminal propeptide of type III procollagen (PIIINP). Patients were divided into three groups: benign soft tissue lesions (n = 39), localised (n = 29) and metastatic (n = 18) soft tissue sarcomas (STS). Values of PIIINP above the reference range were found in 15%, 28% and 50% of the respective groups. The difference in the concentration of PIIINP was statistically significant between the benign lesions and the localised sarcomas; P = 0.05, and between the benign lesions and the metastatic sarcomas; P less than 0.001. In localised sarcomas there was a correlation between PIIINP and bone-involvement (r = 0.61, P = 0.002) and in metastatic disease between PIIINP and liver metastases (r = 0.77, P less than 0.001). In localised sarcomas the overall survival for patients with a value of PIIINP above the reference range was significantly poorer (P = 0.03) than for patients with values within the reference range, even after stratification for the histological malignancy grade of the tumours (P = 0.04).

Collagen↗
PubMed1992

A new method to measure type I and III collagen synthesis in human skin in vivo: demonstration of decreased collagen synthesis after topical glucocorticoid treatment.

Collagen is synthesized as procollagen and large extra domains known as propeptides are cleaved off enzymatically. In the present study we have measured the carboxyterminal propeptide of type I collagen (PICP) and the aminoterminal propeptide of type III collagen (PIIINP) in blister fluids of human skin. High concentrations of PICP were found in the spontaneous blisters of patients with bullous pemphigoid, erysipelas, or erythema multiforme. Detectable amounts were also found in suction blisters induced on healthy skin. Because the concentrations in suction blisters were several times higher than in corresponding serum, most of PICP and PIIINP was derived from the underlying dermis. This method was used for assessing type I and type III collagen synthesis after topical glucocorticoid treatment. Clobetasol-17-propionate (CP) decreased the concentrations of PICP by 75% after 1 d of treatment, the maximum inhibition (92%) being found after 2 d treatment. PIIINP was also affected. Hydrocortisone and hydrocortisone-17-butyrate also decreased the concentrations of PICP and PIIINP, but less markedly than CP. Partial recovery was seen 3 d after stopping the treatment. Thus measurement of collagen type specific propeptides in suction blisters can be used as an estimate of collagen synthesis in vivo, avoiding both local anesthesia and skin biopsing. With radioimmunoassays for PICP and PIIINP a large number of samples can also be processed simultaneously.

Administration, Topical↗
PubMed1992

Systemic glucocorticoid treatment decreases serum concentrations of carboxyterminal propeptide of type I procollagen and aminoterminal propeptide of type III procollagen.

The effect of systemic glucocorticoid treatment on collagen synthesis in patients with various dermatoses was studied by measuring the carboxyterminal propeptide of type I procollagen (PICP) and the aminoterminal propeptide of type III procollagen (PIIINP) in serum. Changes in the propeptide concentrations were compared with those of osteocalcin, which reflects osteoblastic activity, and tartrate resistant acid phosphatase (TRAP), which reflects osteoclastic activity. The treatment caused significant decreases in levels of PICP, PIIINP and osteocalcin of 38, 34 and 49%, respectively (P less than 0.001). For TRAP, both increases and decreases were seen. The effects on PICP and PIIINP were evident 2-4 days after the onset of steroid therapy. The decrease in PICP was dose-related (r = 0.470, P less than 0.005) but even relatively small doses (0.1 mg of prednisone/kg/1 day) caused a significant reduction in PICP. After cessation of treatment, the levels of PICP returned to the pretreatment level in 1 week. The present study demonstrates that systemic glucocorticoid therapy in humans suppresses the synthesis of type I and III collagens and also non-collagenous bone matrix proteins.

Acid Phosphatase↗
PubMed1992

Monitoring of multiple myeloma and bone marrow fibrosis with aminoterminal propeptide of type III collagen (PIIINP).

Bone marrow fibrosis is known in myelomatosis and depends on the extent of plasma cell infiltration. The serum concentration of the aminoterminal propeptide of type III procollagen (PIIINP) has previously been reported to reflect fibrogenesis in the marrow in myelofibrosis. Here we followed 15 consecutive patients with newly diagnosed multiple myeloma with repeated PIIINP measurements during treatment with intermittent courses of melphalan and prednisolone. PIIINP was found to change with clinical behaviour of the disease, nonresponders and patients with recurrent disease having elevated values and the values in responders decreasing to the normal level or remaining there. Collagen fibres in plasma cell infiltrates of biopsies from bone marrow or skeletal tumours of these patients stained heavily with antibodies against PIIINP. Our results suggest that PIIINP works as a noninvasive indicator of bone marrow fibrogenesis. In multiple myeloma PIIINP is a sensitive, but not specific marker of disease course.

Adult↗
PubMed1992

Connective tissue response to major surgery and postoperative infection.

Type I and type III collagen are components of a healing wound, and major structural proteins. According to our previous study, wound fluid concentrations of the liberated propeptide extensions of procollagens can be used to monitor collagen synthesis in the wound. Serum concentrations of the carboxyterminal propeptide of type I procollagen (PICP), and the aminoterminal propeptide of type III procollagen (PIIINP) were studied here for up to half a year in 102 patients, admitted for major abdominal surgery. In a frequent follow-up (n = 9), one minimum and two maxima were found for S-PICP, occurring 1 day, 7 days, and 2 months after surgery, respectively. S-PIIINP had a minimum at 1 day and a peak at 10 days. Relative changes (follow-up result/pre-operative concentration) of the propeptides in 50 uncomplicated patients were compared. The 1-day minimum of S-PICP was 0.60 (SD 0.18), and that of S-PIIINP 0.89 (0.27), (P less than 0.0001, 95% CI for the mean difference 0.21 to 0.36). The 7-day peak of S-PICP was 1.4 (0.5), and that of S-PIIINP 2.5 (1.2), (P less than 0.0001, CI 0.81 to 1.42). The 2-month-peak of S-PICP was 1.6 (0.3), and at the same time the relative S-PIIINP was still 1.7 (0.3) without any separate peak. Major infectious (n = 8) and other (12) complications, exploratory procedures (22) and patients with abnormal pre-operative propeptide levels (8) were studied separately. Two early deaths were excluded. Only major infection had a remarkable effect on the responses of S-PICP (3/8) and S-PIIINP (5/8).(ABSTRACT TRUNCATED AT 250 WORDS)

Collagen↗
PubMed1992

Aminoterminal propeptide of type III procollagen in ovarian cancer. A review.

The concentration of the aminoterminal propeptide of type III procollagen (PIIINP) in serum is a measure of the activity of the metabolism of type III collagen, which is a major constituent of soft connective tissues and of the connective tissue stroma of solid tumours. In advanced ovarian carcinoma, serum PIIINP serves as a tumour-associated antigen, its changes reflecting and preceding changes in the clinical behaviour of the malignancy. Elevated values of serum PIIINP are also observed in endometrial and cervical malignancies, though less frequently than in ovarian tumours. Very high concentrations of PIIINP are found in ovarian carcinoma ascites, suggesting an ongoing fibro-proliferative reaction in the peritoneal cavity as a response to the tumour.

Antigens, Tumor-Associated, Carbohydrate↗
PubMed1992

Metabolism of the aminoterminal propeptide of type III procollagen in cultures of human proximal tubular cells.

Degradation of the intact form of the aminoterminal propeptide of type III procollagen (PIIINP) has been established in the liver, whereas the col 1 domain of PIIINP is extracted by the kidneys. We used native human PIIINP and col 1 domain of PIIINP to investigate the degradation of PIIINP in cultures of human proximal tubular cells. Normal renal tissue was obtained from the healthy part of kidneys surgically removed and from biopsies from a total of 10 patients. The degradation was characterized by incubation of [125I]-PIIINP followed by gel filtration. We found that in physiological concentrations (4.4 micrograms l-1 and 11.9 micrograms l-1 intact PIIINP was almost totally degraded, but not col 1 domain. High concentrations of PIIINP (20-50 micrograms l-1) had a non-linear, non-monoexponential degradation over time, which suggests several steps. Gel filtration of [125I]-PIIINP after 1 h, 3 h, 6 h and 24 h of incubation confirmed the observation by showing the rapid formation of a high-molecular-weight fraction, followed by the slower formation of a low-molecular-weight fraction. The high-molecular-weight fraction was PIIINP immunoreactive, but not the low-molecular-weight fraction. We conclude that cultures of human proximal tubular cells degrade intact human PIIINP by the formation of high- and low-molecular-weight fractions. Earlier findings that extraction of the PIIINP col 1 domain takes place in the kidneys, cannot be explained by degradation by the proximal tubular cells.

Cells, Cultured↗
PubMed1991

Aminoterminal propeptide of type III procollagen in cerebrospinal fluid. Variation with age and in childhood leukemia.

Analyses of the aminoterminal propeptide of type III procollagen (PIIINP) in the cerebrospinal fluid (CSF) of 55 children and five young adults without any structural central nervous system (CNS) lesion are reported. The concentration was age-dependent, in that infants and small children had quite high values, whereas the concentration remained relatively constant after the age of 1.5 years. The concentrations of PIIINP in the CSF of 44 children with acute lymphoblastic leukemia (ALL) were prospectively determined at the time of diagnosis and during treatment, since deposition of type III collagen is known to occur during fibroproliferative responses triggered by inflammation. Chemical arachnoiditis is known to be associated with intrathecal methotrexate therapy in children with leukemia. The mean concentration in these children at diagnosis (5.8 micrograms/l +/- SD 2.8 micrograms/l) did not differ from that in age-matched controls (6.7 micrograms/l +/- SD 3.2 micrograms/l). Depending on type of the disease, the children were treated according to two different protocols. PIIINP concentrations were significantly higher during the therapy phases which included intrathecally administered methotrexate (P less than 0.001) than at diagnosis of the disease. Corticosteroid treatments were always associated with a significant decrease in PIIINP concentrations (P less than 0.01 and P less than 0.001 in the two groups, respectively), irrespective of the therapy phase. The results suggest that an increase in PIIINP concentration in the CSF of children with ALL is an indicator of a fibroproliferative response in the arachnoid. Corticosteroids may repress this response and possibly also prevent the development of adhesions in the arachnoid.

Adolescent↗
PubMed1991

Effect of dextran on synthesis, secretion and deposition of type III procollagen in cultured human fibroblasts.

When subconfluent cultures of primary human skin fibroblasts are incubated for 20 h in the presence of 5% neutral dextran, the newly synthesized procollagens are shifted from the medium into the pericellular matrix fraction. This is accompanied by an overall decrease by 30-50% in the secretion rates of these proteins, as indicated by the incorporation of tritiated proline into collagenase-sensitive macromolecules and by radioimmunoassays for the propeptide regions of type I and III procollagens. Inhibition of tyrosine sulphation in newly formed type III procollagen by NaClO3 does not change the distribution of this protein between the medium and matrix fractions either in the presence or in the absence of the polymer. Processing of type III procollagen at its N-terminus is incomplete in this situation, irrespective of whether the protein is present mainly in the medium or in the pericellular matrix. The concentrations of the mRNAs for the pro alpha 1(I)- and pro alpha 1(III)-chains of procollagens and for actin were monitored for up to 20 h; in the dextran-treated cultures these are not different from the corresponding concentrations in control cultures, indicating that the rapid down-regulation of the synthesis of type I and III procollagens in response to the enhanced pericellular matrix deposition induced by dextran is not due to transcriptional mechanisms.

Blotting, Northern↗
PubMed1991

Effects of a combined estrogen-gestagen regimen on serum levels of the carboxy-terminal propeptide of human type I procollagen in osteoporosis.

Estrogen stimulates osteoblastic collagen production in vitro, but whether the same stimulation takes place in vivo is still unknown. To test the stimulatory effects of a combined estrogen-gestagen regimen in vivo we monitored serum levels of the carboxy-terminal propeptide of human type I procollagen (S-PICP) in a group of 12 osteoporotic women over a 150 week treatment period. Spinal bone mineral content (BMC) increased to a maximum of 5% over pretreatment values around week 90. Serum alkaline phosphatase (S-AP) and serum bone gla protein (S-BGP) both fell from initial values of 220 U/liter and 39 ng/ml, respectively, to 146 U/liter (p less than 0.01) and 27.2 ng/ml (NS) around week 60 and remained reduced over the remaining treatment period. S-PICP also fell from 117 to 68 micrograms/liter at week 60 and 70 micrograms/ml at week 150 (P less than 0.01). This is equal to a reduction to 32 +/- 10% pretreatment levels. The reduction in S-PICP was not significantly different from that of the other two markers of bone formation (S-AP and S-BGP). Thus, provided the metabolic clearance of PICP remains unaltered after hormone replacement therapy, no major stimulation of osteoblastic collagen type I synthesis was demonstrable during estrogen-gestagen treatment in this population of osteoporotic women. The changes in bone markers seen in this study are therefore consistent with an estrogen-mediated reduction in the frequency of remodeling activation. Because of the reduction in bone turnover and methodologic limitations of bone marker assays, however, smaller increases in the amount of bone formed per activation could remain undetectable.

Aged↗
PubMed1991

Use of a marker of collagen formation in osteoporosis studies.

Type I collagen accounts for most of the organic matrix of bones, but it is also an important constituent of soft connective tissue. Assessment of the turnover of such collagen is particularly relevant to bone metabolism. Determination of the carboxyterminal propeptide of type I procollagen (PICP) is a means of estimating the rate of type I collagen synthesis in the body. Serum concentrations of PICP have been shown to correlate with the rate of bone formation.

Adult↗
PubMed1991

The carboxy-terminal propeptide of type I procollagen in serum as a marker of bone formation: the effect of nandrolone decanoate and female sex hormones.

Seventy-nine osteoporotic (prior forearm or vertebral fracture), but otherwise healthy, postmenopausal women (aged 55 to 75 years) were allocated to two double-blind trials: (1) 39 women received either nandrolone decanoate (anabolic steroid) 50 mg as an intramuscular depot injection or a placebo injection every 3 weeks for 1 year; and (2) 40 women received either 2 mg 17 beta-estradiol plus 1 mg norethisterone acetate or placebo tablets daily for 1 year. Sixty-seven (85%) completed the 1 year of treatment. Serum concentration of type I procollagen carboxy-terminal propeptide (PICP) was measured before and at 3, 6, 9, and 12 months of therapy. In addition, 32 of the women had an iliac bone biopsy taken after double tetracycline labeling. Initial serum PICP correlated significantly with histomorphometrically measured rate of bone formation (r = .4; P less than .05) and plasma bone Gla protein (r = .6; P less than .001), but not with histomorphometrically measured bone resorption or biochemical estimates of bone resorption (fasting urinary hydroxyproline and calcium). Estrogen-progestogen therapy significantly decreased (P less than .001) serum PICP by about 30%, whereas anabolic steroid therapy hardly affected it. We conclude that serum PICP may be used as a noninvasive measurement of bone formation on a group basis. Whereas bone formation is clearly decreased during estrogen-progestogen therapy, it is not affected by long-term therapy with anabolic steroids.

Aged↗