Serum markers of collagen synthesis and degradation in acute respiratory failure patients.

BACKGROUND: Procollagen-derived propeptides reflect the rate of collagen synthesis and type I cross-linked collagen telopeptides (ICTP) collagen I degradation. We studied the collagen metabolism to find out if changes seen in acute respiratory distress syndrome patients are observed in patients with acute respiratory failure (ARF), and whether multiple organ dysfunction (MOD) has impact on it. METHODS: ARF patients with prolonged hospitalisation at least 21 days were included to the study. Blood samples for serum procollagen aminoterminal propeptide I (PINP) and III (PIIINP), and ICTP measurements were collected at study admission (day 0) and on days 2, 7, and 21. RESULTS: The study population comprised 68 patients. Forty-three patients (63%) developed MOD during the first week. PIIINP levels increased in all patients over time. The increase was slightly more pronounced in patients with MOD. During the first week, the synthesis of PIIINP increased more than PINP, and PINP degradation exceeded its production. By day 21, the balance of collagen metabolites returned to baseline. CONCLUSION: The collagen metabolism was altered in ARF patients. The first week was dominated by degradation of type I collagen and production of type III collagen, but by day 21, the collagen composition returned to more stable form.

Influence of high-altitude grazing on bone metabolism of growing sheep.

The objective of this study was to identify the effect of high alpine grazing, associated with varying pasture grass qualities and more pronounced exercise on typically steep slopes, on bone metabolism by improving bone density and enhancing bone turnover in growing sheep. Twenty-four 5-month-old sheep were randomly assigned to two groups. One group was kept at high altitude (HA; 2000-2200 m a.s.l.) for 3 months, and the other group (C; control) remained in the lowlands (400 m a.s.l.). Both groups were kept in grazing pastures with access to good-quality swards. Before the start of the experiment, blood samples were taken, the sheep were weighed, and the left metatarsus of each animal was analysed by quantitative computer tomography. After 1 month, blood samples were taken and body weight was measured, followed by biweekly sampling. Finally, the animals were slaughtered, and the bones were collected for analysis of various bone parameters. Body weight development did not differ between the groups. Concentrations of 25-OH-Vitamin D, carboxy-terminal telopeptide of type I collagen and activities of bone-specific alkaline phosphatase were always higher in the HA group than in the C group, except on the last two sampling dates. Bone mineral content and density increased in both groups during the experiment, but more intensively in the HA group. In addition, the cortical thickness of the HA group increased. The present study demonstrates an increase in bone turnover and mineral content of the bones of the growing sheep grazing in high alpine pastures. The factors associated with HA grazing, therefore, clearly seem to improve bone composition.

Effect of oral clodronate on structural damage and bone turnover in rheumatoid arthritis.

OBJECTIVES: To study the effect of oral clodronate on structural damage and bone metabolism in rheumatoid arthritis (RA). METHODS: In this 2-year proof-of-concept study, sixty patients with at least moderately active RA were randomised to receive anti-rheumatic therapy alone or together with oral clodronate 1600 mg daily. Radiographs of hands and feet and serum samples for bone biomarkers were studied at baseline and at 24 months. RESULTS: At 24 months, progression of radiographic joint damage was similar in the 2 groups. Clodronate suppressed carboxyterminal cross-linked peptide of type I collagen (p=0.03) and aminoterminal propeptide of type I procollagen (p=0.01). Eight patients (27%) withdrew from clodronate therapy due to adverse drug reactions. CONCLUSIONS: Oral clodronate did not retard the focal bone damage in RA despite its beneficial effect on overall bone metabolism, as judged by the decrease in the reference bone biomarkers.

Genitourinary prolapse and joint hypermobility are associated with altered type I and III collagen metabolism.

PURPOSE: The aim of this study was to determine whether benign joint hypermobility (BJH) is associated with urogenital prolapse and altered collagen metabolism. METHODS: 43 postmenopausal women with previous vaginal hysterectomy operated due to genitourinary prolapse were recruited. Each patient was also evaluated for joint hypermobility. The collagen metabolism was studied measuring serum concentrations of type I and III procollagen aminoterminal propeptides and trivalently cross-linked carboxyterminal telopeptide of type I collagen. RESULTS: Clinical joint hypermobility was found in 35% patients. Women with joint hypermobility had higher concentration of aminoterminal propeptide for type I procollagen and the values were statistically significant (P < 0.0178). Recurrent prolapse was found in 47% of the patients with BJH as compared to non-hypermobile group (25%). In this subgroup the results were statistically significant (P < 0.0085) for type III collagen. Also, the mean serum concentration for type III procollagen was significantly increased above the reference limit. CONCLUSIONS: Women with joint hypermobility have more recurrent genital prolapse as compared to women with normal joint mobility. Plain hypermobility was associated with higher concentrations for type I procollagen. Patients with recurrent prolapse and joint hypermobility have significantly high concentrations for type III procollagen.

Toll-like receptor 9 ligands enhance mesenchymal stem cell invasion and expression of matrix metalloprotease-13.

Human mesenchymal stem cells (hMSCs) are multipotent cells that are found in the bone marrow. Inflammation and tissue damage mobilize MSCs and induce their migration towards the damaged site through mechanisms that are not well defined. Toll-like receptor-9 (TLR9) is a cellular receptor for microbial and vertebrate DNA. Stimulation of TLR9 induces inflammatory and invasive responses in TLR9-expressing cells. We studied here the expression of TLR9 in human MSCs and the effects of synthetic TLR9-agonists on their invasion. Constitutive expression of TLR9 was detected in human MSCs but the expression was suppressed when MSCs were induced to differentiate into osteoblasts. Using standard invasion assays and a novel organotypic culture model based on human myoma tissue, we discovered that stimulation with the TLR9 agonistic, CpG oligonucleotides increased the invasion capacity of undifferentiated MSCs. Simultaneously, an increase in MMP-13 synthesis and activity was detected in the CpG-activated MSCs. Addition of anti-MMP-13 antibody significantly diminished the CpG-induced hMSC invasion. We conclude that treatment with TLR9-ligands increases MSC invasiveness, and this process is at least partially MMP-13-mediated.

Combination drug strategy in recent-onset rheumatoid arthritis suppresses collagen I degradation and is associated with retardation of radiological progression.

OBJECTIVE: To assess whether serum C-terminal cross-linking telopeptide of type I collagen (ICTP), a marker of type I collagen degradation, has any additional value in the assessment of treatment effect in patients with early rheumatoid arthritis (RA). METHODS: A total of 182 patients were randomized to treatment either with three disease-modifying anti-rheumatic drugs (DMARDs) and low-dose prednisolone (COMBI) or with a single DMARD with or without low-dose prednisolone (SINGLE). We investigated the prognostic value of serum ICTP level for the progression of joint destruction in X-rays (Larsen's score) from baseline to 2 years. RESULTS: There was a statistically significant decrease in serum ICTP levels from baseline to 1 year. At 6 months, the serum ICTP level was lower in the COMBI patients compared to that of the SINGLE cases (p = 0.008, after adjustment for baseline ICTP). When grouping the patients according to serum ICTP tertiles at 6 months, there was a statistically significant trend for increasing median change in Larsen score from baseline to 2 years from lowest to highest ICTP tertile in the SINGLE patients [p = 0.008, after adjustment for 28-joint Disease Activity Score (DAS28) score and RF status at baseline], while in the COMBI, the change remained low in all ICTP tertiles. CONCLUSIONS: The COMBI strategy for recent-onset RA results in early suppression of type I collagen degradation, which is reflected in radiological joint damage at 2 years. Serum ICTP at 6 months may be useful for identifying those RA patients whose treatment should be intensified to prevent further joint damage.

Sensitivity and specificity of autoantibodies binding to citrullinated carboxyterminal telopeptides of types I and II collagens in an early arthritis series.

OBJECTIVE: To assess the specificity and sensitivity of autoantibodies binding to citrullinated carboxyterminal telopeptides of types I and II collagens in an early arthritis series. METHODS: A cohort of 146 patients from the Kuopio 2000 Arthritis Survey having RA, AS, PsA, ReA, uSpA or undifferentiated arthritis were studied. Autoantibodies binding citrullinated types I and II carboxytelopeptides were measured in two different inhibition ELISA assays. Sera from 135 adult persons were used as controls. RESULTS: In RA, the sensitivities were 0.83 with long type I telopeptide and 0.78 with long type II telopeptide and the respective specificities were 0.94 and 0.93, while the corresponding values in other inflammatory joint diseases were much lower. The likelihood ratio in RA increased with longer peptides from 4.20 to 14.06 for type I telopeptide and from 2.74 to 11.67 for type II telopeptide. CONCLUSION: The antibody assay using long telopeptide from type I collagen was the most specific and sensitive method in every diagnostic category, although in the arthritides other than RA, binding was much less abundant and possibly citrulline-independent.

Atrial extracellular matrix remodelling in patients with atrial fibrillation.

UNLABELLED: Atrial fibrillation (AF) is the most frequent clinical arrhythmia. Atrial fibrosis is an important factor in initiating and maintaining AF. However, the collagen turnover and its regulation in AF has not been completely elucidated. We tested the hypothesis that the extracellular matrix changes are more severe in patients with permanent AF in comparison with those in patients in sinus rhythm (SR). Intraoperative biopsies from the right atrial appendages (RAA) and free walls (RFW) from 24 patients with AF undergoing a mini-Maze procedure and 24 patients in SR were investigated with qualitative and quantitative immunofluorescent and Western blot analyses. As compared with SR, all patients with AF exhibited dysregulations in collagen type I and type III synthesis/degradation. Tissue inhibitors of metalloproteinases (TIMP2) was significantly enhanced only in RAA-AF. As compared with SR, collagen VI, matrix metalloproteinases MMP2, MMP9 and TIMP1 were significantly increased while TIMP3 and TIMP4 remained unchanged in all AF groups. Reversion-inducing cysteine-rich protein with Kazal motifs (RECK), a newly discovered MMPs inhibitor, was elevated in RFW as compared to RAA-AF (P<0.05) and RFW-SR (P<0.05). The level of transforming growth factor (TGF)-beta1 was higher in AF than SR. Smad2 and phosphorylated Smad2 showed an elevation in RFW-AF as compared to RFW-SR, RAA-AF, and RAA-SR groups (P<0.05). CONCLUSIONS: Atrial fibrosis in AF is characterized by severe alterations in collagen I and III synthesis/degradation associated with disturbed MMP/TIMP systems and increased levels of RECK. TGF-beta1 contributes to atrial fibrosis via TGF-beta1-Smad pathway by phosphorylating Smad2. These processes culminate in accumulations of fibrillar and non-fibrillar collagens leading to excessive atrial fibrosis and maintainance of AF.

Change of diagnoses and outcome of patients with early inflammatory joint diseases during a mean 13-month follow-up.

OBJECTIVE: To assess the state of the disease and verify the diagnoses during a 7-24-month follow-up of adult patients with newly diagnosed inflammatory joint diseases in a defined population. METHODS: Patients with previously undiagnosed synovitis in at least one peripheral joint or signs of inflammation in sacroiliac, glenohumeral or hip joints were enrolled on their first hospital visit in 2000 and followed-up for up to 24 months in Kuopio. RESULTS: A total of 138/173 adult patients completed a mean 13-month follow-up. During the follow-up the diagnosis was specified for 15/81 (19%) patients previously classified as undifferentiated arthritis (UA). Eight patients developed rheumatoid arthritis (RA). Of 28 patients with RA, 92% were on disease-modifying anti-rheumatic drugs (DMARDs) and 75% had a combination treatment with two or more DMARDs. According to the diagnosis at baseline, 75% of cases with RA, 38% with spondyloarthropathies (SpAs) and 42% with UA had active synovitis or arthralgia at follow-up. In multivariate analysis, older patients at disease onset were less likely to be in remission (p = 0.011). CONCLUSION: The diagnosis could be specified for 19% of patients with UA. Fifteen of 20 patients with RA had an active disease despite treatment with DMARDs. Patients with SpAs and UA had a better short-term outcome. Patients with active disease need aggressive therapy in all age groups.

Bone metabolism of milk goats and sheep during second pregnancy and lactation in comparison to first lactation.

Substantial losses of skeletal tissue occur during late pregnancy and lactation. The goal of the present study was to follow these changes in pregnant and lactating goats and sheep, compare these two species during their second lactation, and also compare the results to the first lactation. Blood samples were collected from 12 adult dairy goats (Saanen goat) and sheep (Ostfriesen milk sheep) monthly during gestation, 2 or 3 days postpartum (pp), 2 weeks pp, 4 weeks pp, and then monthly during lactation until 7 months after parturition. Total bone mineral content (BMC) and total bone mineral density (BMD) were quantified using peripheral quantitative computed tomography (pQCT) at the same intervals as the blood was taken. Bone resorption was assessed in serum using two different domains of the carboxyterminal telopeptide of type I collagen (ICTP and crosslaps). Bone formation was quantified in serum with osteocalcin (OC) and bone-specific alkaline phosphatase (bAP). In addition, Ca and 1,25 dihydroxy vitamin D (VITD) were determined in serum. The same procedure was done during the first and second gestation and lactation. Mean ICTP and crosslaps concentrations of the two animal species showed an increase in the last month of gestation. In contrast, mean OC concentrations decreased slowly from the 2nd month of pregnancy until the first week pp. Also mean bAP activities showed a similar time course. Total BMC and BMD decreased until the first week pp in both species. Afterwards, BMC increased again during lactation. BMD levels of sheep and goats returned to prepartum levels during lactation. Vitamin D concentrations peaked in the first week pp. Only VITD concentrations in goats stayed elevated compared with prepartum values throughout the whole lactation during the second lactation. Around parturition and at the beginning of lactation, the bone resorptive phase of bone remodelling is accelerated, but is uncoupled from the process of bone formation. The mineral decrease in bone of these lactating animals seems to be reversible. Since during lactation, bone remodelling has bone resorption and formation phases tightly coupled. Interestingly, in these species, the bone loss in the second pregnancy and lactation measured with BMC and BMD is not as prominent as in the first lactation, but shows almost the same course, although the animals gave more milk in the second lactation. It seems that the organism adapts to the circumstances more easily in the second lactation compared to the first lactation in these two species.

Influence of different calcium contents in diets supplemented with anionic salts on bone metabolism in periparturient dairy cows.

At the initiation of lactation, Ca homeostatic mechanisms have to react to a tremendous increase in demand for Ca. Mobilization of Ca from bone and increased absorption from the gastrointestinal tract are required to re-establish homeostasis. It has been shown that dietary anions play an important role in the prevention of milk fever by mobilizing Ca from bone and by increasing Ca absorption in the GI tract. The purpose of the present study was to investigate the influence of different Ca contents in diets supplemented with anionic salts on bone metabolism of dairy cows. Twenty-four holstein cows (housed inside, second to fourth lactation) without a milk fever history were divided into four groups (A, B, C, D). Each group was fed a different diet which was given from day 263 of gestation till the day of parturition. Group A and B received a low calcium diet (4 g/kg DM) whereas group C and D received a high Ca diet (8 g/kg DM). In addition group B and D received anionic salts. The DCAD was calculated with the formula: DCAD (mEq/kg DM)=(0.2 Ca2++0.16 Mg2++Na++K+)-(Cl-+0.6 S2-+0.65 P3-). Blood and urine samples were collected on days 256, 270 and 277 of gestation, on the day of parturition as well as the following 5 days and on days 9, 14 and 19 after parturition. Serum Ca, P, Mg, ICTP, OC, VITD, PTH and urinary pH were analysed. The bone resorption marker ICTP showed a significant increase after parturition in all the groups. On the contrary, the bone formation marker OC decreased after parturition in all the groups. The VITD concentrations in group D and the urinary pH in group B were significantly lower compared to the other groups (p<0.05). The Ca concentrations tended to be higher in group B around parturition than in all the other groups. No significant influence of the four different diets on all the other parameters could be shown. In conclusion, this data showed that the addition of anions and the different Ca contents had no significant influence on bone resorption and bone formation markers. This may be because of the fact that the dietary cation-anion balance was not low enough (DCAD-group A: 181 mEq/kg DM, group B: -48 mEq/kg DM, group C: 210 mEq/kg DM and group D: 28 mEq/kg DM) to induce a metabolic acidosis with all its positive effects on calcium metabolism.

Genetic and constitutional influences on bone turnover markers: a study of male twin pairs.

Biochemical markers of bone turnover originating from type I procollagen synthesis or type I collagen breakdown were examined in men using a classic twin study design based on monozygotic (MZ) and dizygotic (DZ) twins. The aim was to estimate the influence of heredity (genes and shared family childhood elements) and constitutional factors in determining procollagen type I amino-terminal propeptide (PINP), type I collagen carboxy-terminal telopeptide (ICTP), and urinary amino-terminal type I collagen telopeptide (NTx) marker levels in a sample of in 98 MZ and 108 DZ male twin pairs. We are not aware of any prior studies conducted in men that address the influence of genetic factors on bone turnover marker variability. The findings support a dominant role for heredity in the variation of bone resorption marker levels in men, with additive genetic effects explaining two-thirds of the variance in the bone resorption markers NTx and ICTP. Genetic factors may contribute less for PINP, a marker of bone formation. The genetic loci influencing PINP or NTx and body weight/disc axial area, although related in part, appeared to be largely independent, indicating that genetic effects on bone turnover are unlikely to be to a large degree a result of genetic regulation of individual body weight.

PINP: a serum biomarker of bone formation in the rat.

Serum PINP has emerged as a reliable marker of bone turnover in humans and is routinely used to monitor bone formation. However, the effects of PTH (1-34) on bone turnover have not been evaluated following short-term treatment. We present data demonstrating that PINP is an early serum biomarker in the rat for assessing bone anabolic activity in response to treatment with PTH (1-38). Rat serum PINP levels were found to increase following as few as 6 days of treatment with PTH (1-38) and these increases paralleled expression of genes associated with bone formation, as well as, later increases in BMD. Additionally, PINP levels were unaffected by treatment with an antiresorptive bisphosphonate. PINP may be used to detect PTH-induced early bone formation in the rat and may be more generally applicable for preclinical testing of potential bone anabolic drugs.

The predictive role of bone turnover markers for BMD in middle-aged men.

Measurement of bone turnover markers has been proposed as a potentially valuable clinical laboratory aid in osteoporosis risk assessment. These markers may allow quantitative evaluation of rates of bone loss, and thereby identify persons at risk for osteoporosis at an earlier stage. As far as we know, this is the longest longitudinal study on bone turnover markers conducted in adult men. The objectives of this study were to determine whether markers of bone formation (type I procollagen amino-terminal propeptide, PINP, and carboxy-terminal propeptide, PICP), and of bone resorption (type I collagen carboxy-terminal telopeptide, ICTP), are predictive of changes in lumbar spine and femoral neck BMD over a 5-year period, and to determine the ability of the bone resorption marker urine amino-terminal telopeptide (NTx) to explain the variance in BMD change over the past 5 years in a group of men 35-69 years old. In this group, NTx was the only marker to correlate significantly with BMD changes at the femoral neck (r = -0.21), but not at the spine. The use of the biochemical markers studied to predict change in bone density in adult men in middle-aged years is of very limited value.

Inhibitory characteristics of citrullinated telopeptides of type I and II collagens for autoantibody binding in patients with rheumatoid arthritis.

OBJECTIVE: To study how soluble citrullinated telopeptides of type I and II collagens inhibit the binding of autoantibodies to the respective antigens immobilized onto solid phase, and to use modifications of previous methods to re-analyse rheumatoid arthritis (RA) and control serum samples. METHODS: Autoantibody binding was inhibited with normal or citrullinated carboxytelopeptides using enzyme-linked immunosorbent assay (ELISA) methods. Serum samples were available from 120 patients with RA and 81 controls. RESULTS: Autoantibodies that bind normal C-telopeptides were not inhibited with soluble normal or citrullinated telopeptides. However, the antibodies that bind only citrullinated telopeptides could be inhibited with corresponding citrullinated telopeptides. Thus, it is not necessary to study the binding of autoantibodies to normal collagens if the specificity of their binding is assessed by immunological inhibition. For type I telopeptide, there are two arginines, the latter of which, when citrullinated, is important for binding. For type II telopeptide, there is one arginine, which is important when citrullinated. The other amino acids, e.g. the last alanine, have only a slight effect on binding. These improved methods differentiate better between RA patients, who have specific citrullinated autoantibodies, and controls than previous ELISA methods. CONCLUSIONS: Based on inhibition assay, it is possible to measure the autoantibodies binding specifically to citrullinated telopeptides of type I and II collagens. When only one assay is involved, variance is decreased and the overall performance is easier than before.

The effects of first gestation and lactation on bone metabolism in dairy goats and milk sheep.

The goal of the present study was to compare mobilization rate of calcium (Ca) from bone in pregnant and lactating goats and sheep. Blood samples were collected from goats and sheep monthly during pregnancy and at 1, 2, and 4 weeks postpartum (pp) and monthly during lactation until 6 months after parturition. Total bone mineral content (BMC) and total bone mineral density (BMD) were quantified using peripheral quantitative computed tomography at the same intervals as the blood was taken. Bone resorption was assessed by immunoassays quantitating two epitopes of the carboxyterminal telopeptide of type I collagen (ICTP, CTX). Bone formation was estimated by quantifying serum osteocalcin (OC) and bone-specific alkaline phosphatase (bAP). In addition, Ca and 1,25-dihydroxy vitamin D (1,25-VITD) concentrations were determined in serum. Mean ICTP and CTX concentrations of both animal species increased the first week after parturition. By the second week pp, the concentrations of both markers had decreased toward early gestation levels. In contrast, mean OC concentrations continually decreased until the 1st week pp. By the 2nd week pp, the mean concentrations of OC started to increase again. Mean bAP activities decreased during gestation and reached a nadir in the first week pp in goats and 4 weeks pp in sheep. Afterwards, mean bAP activities increased again in goats and sheep. 1,25-VITD concentrations peaked the first week pp and returned to early gestation values thereafter. Total BMC and BMD decreased from the 4th month of pregnancy until the 1st week pp in both species. Afterwards, BMC increased throughout the first month pp in goats and the first 3 months pp in sheep. BMD levels of sheep and goats returned to prepartum levels during lactation. The resorptive phase of bone remodeling is accelerated at parturition and in early lactation and is uncoupled from the process of bone formation. This allows the animal to achieve Ca homeostasis at the expense of bone. Increased bone remodeling during lactation may represent physiological mechanisms to help replace the maternal skeleton lost as the animal adapted to enormously increased Ca losses to the fetus and milk in late gestation and early lactation.

Are there autoantibodies reacting against citrullinated peptides derived from type I and type II collagens in patients with rheumatoid arthritis?

OBJECTIVES: To assess the possible presence in patients with rheumatoid arthritis (RA) of autoantibodies recognising citrullinated peptides derived from type I and II collagens. METHODS: Firstly, the binding of four pairs of synthetic peptides (arginine-containing and artificially citrullinated forms) related to different regions of human type II collagen were tested with sera from 120 patients with RA and 81 controls. Secondly, two similar pairs of peptides related to the carboxy terminal telopeptides of the alpha1 and alpha2 chains of human type I collagen were tested. RESULTS: 42-53% of the RA sera showed increased binding of arginine peptides related to type II collagen. However, 12 RA sera bound the citrullinated form of the alpha1(II) telopeptide more strongly than the corresponding arginine peptide. 20 RA sera bound the citrullinated carboxytelopeptide from the alpha1 chain of type I collagen (alpha1(I) telopeptide) more strongly than the respective arginine peptide. The correlation between the autoantibodies to type I and II collagen telopeptides was r(s) = 0.576, p < 0.001. Anti-cyclic citrullinated peptide (anti-CCP) assay was positive in 71/120 (59%) patients with RA. An anti-CCP assay detects a different subgroup of antibodies than anti-telopeptide assays. However, both anti-telopeptide and anti-CCP antibodies were increased in patients with RA. CONCLUSION: Some patients with RA were identified whose sera contained antibodies that specifically bound citrullinated peptides related to the carboxy terminal telopeptides of the alpha1 and alpha2 chains of type I collagen and the alpha1 chains of type II collagen (sequences YYXA, FYXA, and YMXA, where X stands for citrulline).

Effect of jaundice and its resolution on wound re-epithelization, skin collagen synthesis, and serum collagen propeptide levels in patients with neoplastic pancreaticobiliary obstruction.

BACKGROUND: Wound and anastomotic healing is considered to be delayed in patients with obstructive jaundice. The study was designed to find out whether the healing of experimental suction blister wounds, skin collagen synthesis, and serum procollagen levels are affected by obstructive jaundice, and if biliary drainage may cause any alterations in these processes. PATIENTS AND METHODS: Suction blisters were induced on 24 patients with obstructive jaundice caused by neoplastic pancreaticobiliary obstruction and 17 control patients with the corresponding condition without jaundice, to compare healing parameters and collagen synthesis between the groups. A second set of suction blisters were induced on 13 formerly jaundiced patients after the resolution of jaundice and on 14 control patients, to find out whether drainage or time modifies healing or collagen synthesis. By using this model, it is possible to evaluate the re-epithelization and inflammation on wound healing and to assess the baseline skin collagen synthesis. The healing of suction blisters was followed up by measuring water evaporation and blood flow in the wound. Blister fluids and serum samples were collected to study collagen propeptides. RESULTS: Healing of the blister wound was unaffected by obstructive jaundice. Drainage had no effect on healing. The baseline synthesis of type I and type III collagen in the skin was decreased in jaundiced patients. Biliary drainage improved the synthesis. Serum type III procollagen propeptide levels were elevated in jaundiced patients, but began to normalize after drainage. CONCLUSION: Healing of an experimental blister wound is not disturbed by obstructive jaundice. The decreased baseline skin collagen synthesis is partly restored by the resolution of jaundice. The results indicate that cell protein synthesis is disturbed earlier than cell dynamics in obstructive jaundice. The elevated serum PIIINP levels, which are most likely to be related to early fibrosis in liver, decreased after drainage.

Influence of phytase added to a vegetarian diet on bone metabolism in pregnant and lactating sows.

The purpose of the study was to find out if the supplementation of phytase to a diet of gestating and lactating sows has any effects on performance and bone parameters of the animals. Forty primiparous gilts were assigned into four groups: group A with phytase [4.2 g total phosphorus (P)/kg (gestation) and 4.5 g total P/kg (lactation)], group B without phytase (with phytase supplementation in diet for rearing) and same P content as group A, group C without phytase and higher P contents [5.0 g total P/kg (gestation) and 5.5 g total P/kg (lactation)] and group D with the same diet as group B (no phytase during the rearing). A 6-phytase was used in this trial (750 FTU/kg diet). The four diets were fed during gestation and lactation. Faeces were collected to determine apparent digestibility of minerals. Blood samples were taken to analyse minerals and bone markers. After weaning the sows were slaughtered and the bones of one hind leg were prepared to measure bone mineral density (BMD) and bone mineral content (BMC) of the tibia. Bone ash and mineral content of the phalanx III were determined. Mean P concentrations in serum decreased during gestation and lactation. But there were no significant differences between the groups. Bone formation marker bone-specific alkaline phosphatase decreased at the beginning of lactation whereas bone resorption marker serum crosslaps increased. The BMD and BMC of the tibia were slightly higher in the groups fed higher concentrations of P and phytase. The ash and mineral contents of the phalanx were the highest for the group fed the highest concentration of P. The apparent digestibility of P increased during gestation mostly in group A (57%--> 69%). In conclusion, high P content and addition of phytase to the diet induced a slightly higher ash content of the bones. It is of high importance, that sows during gestation absorb enough P, to avoid lamenesses and sudden fractures. As not many studies with phytase have been performed during gestation and lactation in sows yet, we can recommend, that phytase as supplement can be used to keep P in the diet at a lower level without negative consequences for bone health.