The influence of temperature during water-quench rapid heat treatment on the microstructure, mechanical properties and biocompatibility of Ti6Al4V ELI alloy

This study investigates the influence of a rapid heat treatment followed by water-quenching on the mechanical properties of Ti6Al4V ELI alloy to improve its strength for use in implants. Prior to the experiment, a dilatometry test was performed to understand the progressive α-to β-phase transformation taking place during heating. The results were then used to carry out heat treatments. Microstructure was analysed using SEM, EBSD, EDX and XRD techniques. Vickers micro-hardness, tensile and high cycle rotating bending tests were used to analyse the influence of the $\alpha'$-phase fraction on the strength of the studied alloy. Results show that this process can provide a Ti6Al4V ELI alloy with a better Yield Strength (YS)/uniform deformation (ε_u) ratio and improved high cycle fatigue strength than those observed in the current microstructure used in medical implants. Lastly, cytotoxicity tests were performed on two types of human cells, namely MG63 osteoblast-like cells and fibroblasts. The results reveal the non-toxicity of the heat-treated Ti6Al4V ELI alloy.

Engulfment of ceramic particles by fibroblasts does not alter cell behavior

Despite many studies, the impact of ceramic particles on cell behavior remains unclear. The aim of the present study was to investigate the effects of nano-sized ceramic particles on fibroblastic cells. Fibroblasts (dermal fibroblasts freshly isolated from skin samples and WI26 fibroblastic cells) were cultured in a monolayer in the presence of alumina or cerium-zirconia particles (≈50 nm diameter) at two concentrations (100 or 500 μg ml^-1). Fluorescent alumina particles were also used. The following properties were analyzed: cell morphology, cytoplasmic ceramic incorporation (using confocal and transmission electron microscopy) and migration (using a silicon insert). Sedimentation field-flow fractionation (SdFFF) was also used to evaluate the rate of incorporation of ceramic particles into the cells. Finally, after treatment with various concentrations of ceramic particles, fibroblasts were also included in a collagen type I lattice constituting a dermal equivalent (DE), and the collagen lattice retraction and cell proliferation were evaluated. In monolayer conditions, the presence of both alumina and cerium-zirconia ceramic particles did not cause any deleterious effects on cultured cells (dermal fibroblast and WI26 cells) and cell fate was not affected in any way by the presence of ceramic particles in the cytoplasm. Confocal (using fluorescent alumina particles) and electron microscopy (using both alumina and cerium-zirconia particles) showed that ceramic particles were internalized in the WI26 cells. Using fluorescent membrane labeling and fluorescent alumina particles, a membrane was observed around the particle-containing vesicles present in the cytoplasm. Electron microscopy on WI26 cells showed the presence of a classical bilayer membrane around the ceramic particles. Interestingly, SdFFF confirmed that some dermal fibroblasts contained many alumina ceramic particles while others contained very few; in WI26 cells, the uptake of alumina ceramic was more homogeneous. In DE, collagen lattice retraction and cell proliferation were unchanged when WI26 fibroblastic cells contained alumina or cerium-zirconia ceramic particles. Our data suggest that ceramic particles are internalized in the cells by endocytosis. The presence of ceramic particles in the cytoplasm has no affect on cell behavior, confirming the excellent biocompatibility of this material and anticipating a minimal harmful effect of potential wear debris.

Endovascular Treatment of Intracranial Aneurysms with the WEB Device: A Systematic Review of Clinical Outcomes

BACKGROUND AND PURPOSE

Despite the improvement in technology, endovascular treatment of bifurcation intracranial wide-neck aneurysms remains challenging, mainly due to the difficulty of maintaining coils within the aneurysm sac without compromising the patency of bifurcation arteries. The Woven EndoBridge (WEB) device is a recent intrasaccular braided device specifically dedicated to treating such aneurysms with a wide neck by disrupting the flow in the aneurysmal neck and promoting progressive aneurysmal thrombosis.

MATERIALS AND METHODS

Using several health data bases, we conducted a systematic review of all published studies of WEB endovascular treatment in intracranial aneurysms from 2010 onward to evaluate its efficacy and safety profile.

RESULTS

The literature search identified 6 relevant studies (7 articles) including wide-neck bifurcation aneurysms in ≥80% of cases. Clinical data supporting the efficacy and safety of the WEB are limited to noncomparative cohort studies with large heterogeneity from a methodologic standpoint. The WEB deployment was feasible with a success rate of 93%-100%. Permanent morbidity (mRS of >1 at last follow-up) and mortality were measured at 2.2%-6.7% and 0%-17%, respectively. The adequate occlusion rate (total occlusion or neck remnant) varied between 65% and 85.4% at midterm follow-up (range, 3.3-27.4 months).

CONCLUSIONS

Endovascular treatment of bifurcation wide-neck aneurysms with the WEB device is feasible and allows an acceptably adequate aneurysm occlusion rate; however, the rate of neck remnants is not negligible. The WEB device needs further clinical and anatomic evaluation with long-term prospective studies, especially of the risk of WEB compression. Prospective controlled studies should be encouraged.

Knee joint ultrasonography of the ACLT rabbit experimental model of osteoarthritis: relevance and effectiveness in detecting meniscal lesions

OBJECTIVES

To develop a protocol for rabbit knee joint ultrasonography (US); to grade ultrasonographically the meniscal injuries of the anterior cruciate ligament transection (ACLT) rabbit model of osteoarthritis (OA); to assess with US the effectiveness of the ACLT; to compare final US with macroscopy for the evaluation of medial and lateral meniscal injuries depending on the age and weight when ACLT is performed.

METHODS

Twenty-two skeletally mature and adolescent New Zealand white rabbits were housed during the same period at the Institut Claude-Bourgelat, Lyon, France. Surgical ACLT was performed in the left knee of nine adolescent and five adult rabbits. Final US and macroscopic semi-quantitative grading of the meniscal injuries were compared 5 months after ACLT.

RESULTS

A standardised protocol was developed to evaluate the rabbit knee joint. US was performed in both control and ACLT knees. Normal and abnormal meniscal US appearances were described. A semi-quantitative scale to grade US meniscal injuries was created. Macroscopic and US total meniscal scores were significantly positively correlated (P<0.001, r=0.70). US detection of meniscal injuries was 92% sensitive and 87.5% specific compared to macroscopy. Positive and negative predictive values of US were, respectively, 92% and 87.5%. US detection of the ACLT effectiveness was 100% specific and 78.5% sensitive.

CONCLUSION

A significant relationship was found between ultrasonographic and macroscopic grading of meniscal injuries. US was both specific and sensitive in detecting meniscal lesions. We propose US as a non-invasive, non-expensive, in vivo imaging technique for preclinical studies in the ACLT rabbit OA model.

Confocal laser scanning microscopy using dialkylcarbocyanine dyes for cell tracing in hard and soft biomaterials

The aim of this work was to study, in vitro, cell colonization of two biomaterials currently used for bone and cartilage repair, this step being important to understand the function of engineered tissues. Current methods that use histological approaches are not always suited to tissue-engineering analysis. We, therefore, set up a protocol to assess cell distribution, utilizing noninvasive confocal microscopy and fluorescent labels with a far red emission wavelength to optimize scaffold transparency and minimize light scattering. Hard (ceramic substitute) and soft (collagen sponge) biomaterials were seeded respectively, on one side of the scaffold, with human fibroblasts and bovine chondrocytes labelled with carbocyanine dyes (DiD and DiR). The mean penetration depth for DiR labelled fibroblasts and chondrocytes in the two scaffolds, around 270 m, was greater than for DiD (136-218 microm) labelled cells. These depths were independent of cell origin but were influenced by the nature of the scaffolds. Collagen sponge is transparent in contrast to ceramic substitutes where measurements could only be made in opened macropores. Besides the limits of the equipment, the limits of the supports were diffusion for collagen sponges and transmission for ceramic substitutes. Confocal microscopy techniques could thus be used to address the question of cell colonization of porous biomaterials in a noninvasive manner.

A novel in vitro model to study staphylococcal biofilm formation on intraocular lenses under hydrodynamic conditions

PURPOSE

To develop a novel in vitro model to study the formation of Staphylococcus epidermidis biofilm on intraocular lenses (IOLs) from the primary-attachment phase to the biofilm-accumulation phase. The model was designed to replicate intraocular conditions especially by taking into account intraocular hydrodynamics.

METHODS

The model consisted of Tygon tubing connected to a vial containing acrylic hydrophobic IOLs. Three septa, placed along the tubing, allowed, respectively, the artificial aqueous humor's arrival and its elimination and the bacterial suspension's inoculation. A first pump allowed the aqueous humor's movement along the circuit, whereas a second one regulated the flow at which the nutritive environment was regenerated. The whole circuit was placed in a 34 degrees C water bath. Every 2 to 4 hours, lenses were taken from this environment. Bound bacteria were removed by scraping of optical faces and counted. All data are presented as the mean, SD, and coefficient of variation (CV). Comparisons among experiments were performed by one-way analysis of variance (ANOVA).

RESULTS

Calculated CVs were close to 30, showing that biofilm formation was homogeneous. Differences between experiments were nonsignificant for each removal time. The model provided the full kinetics of S. epidermidis biofilm growth on acrylic hydrophobic IOLs, with a stationary phase reached after 28 hours of incubation.

CONCLUSIONS

Biofilm development is modulated by many variables, including environmental factors. The findings in the present study of bacterial colonization of IOLs under intraocular physiological conditions allow understanding and more accurate targeting of biomedical device-related infections such as endophthalmitis.

Complete Unilateral Ureteral Obstruction in the Fetal Lamb. Part II: Long-Term Outcomes of Renal Tissue Development

PURPOSE

We analyzed the dynamics of the renal tissue response to experimental fetal urinary flow impairment concerning renal morphology, extracellular matrix composition, regulators of connective tissue degradation and PAX2 protein expression.

MATERIALS AND METHODS

A total of 26 fetal lambs underwent surgical unilateral ureteral obstruction at 90 days of gestation and 14 twin matched animals served as controls. Kidneys were harvested 10, 20 and 40 days after the prior procedure in groups 1 to 3, respectively and in 1-month-old lambs (group 4). Morphological analysis was done using light microscopy. Picrosirius red staining was used to evaluate the area occupied by extracellular matrix components. Collagen I, III and IV, alpha-smooth muscle actin, MMP-1, 2 and 9, TIMP-1 and 2 and PAX2 protein were assessed using immunochemistry.

RESULTS

All obstructed kidneys were hydronephrotic without dysplasia. Hypoplasia resulting from a decreased NGG was observed. The inflammatory response to obstruction was poor in fetal obstructed kidneys. From 10 days after obstruction interstitial fibrosis was noted and confirmed by an increase in picrosirius red staining. In obstructed kidneys immunochemistry showed an increase in collagen deposition beginning from the papillae and extending through the whole parenchyma. Aberrant interstitial collagen IV deposition was observed. The increase in alpha-smooth muscle actin staining was mainly localized in the blastema and interstitial cells in obstructed kidneys. MMP and TIMP immunostaining was mainly present in tubules throughout the whole nephrogenic period and persisted in mature kidneys. Beginning from 20 days after obstruction a progressive increase in MMP and TIMP expression was noted. This was associated with ectopic expression in the medullary tubules. PAX2 protein was highly expressed in the nephrogenic zone, decreasing progressively to being markedly decreased in control lamb kidneys. No difference was found in PAX2 expression during the fetal period when comparing unobstructed and obstructed kidneys, it but remained strongly expressed in the dilated collecting ducts of obstructed lambs.

CONCLUSIONS

Complete unilateral ureteral obstruction performed in fetal lambs at 90 days of gestation led to pure hydronephrotic transformation, hypoplasia and a marked increase in connective tissue deposition. Inflammatory infiltrates and PAX2 dysregulation were not seen as having a decisive role in these modifications.

Electrophoretic and immunochemical study of collagens from Sepia officinalis cartilage

Electrophoretic and Western blot studies were conducted on collagen fractions extracted from Sepia officinalis (cuttlefish) cartilage using a modified salt precipitation method developed for the isolation of vertebrate collagens. The antibodies used had been raised in rabbit against the following types of collagen: Sepia I-like; fish I; human I; chicken I, II, and IX; rat V; and calf IX and XI. The main finding was that various types of collagen are present in Sepia cartilage, as they are in vertebrate hyaline cartilage. However, the main component of Sepia cartilage is a heterochain collagen similar to vertebrate type I, and this is associated with minor forms similar to type V/XI and type IX. The cephalopod type I-like heterochain collagen can be considered a first step toward the evolutionary development of a collagen analogous to the typical collagen of vertebrate cartilage (type II homochain). The type V/XI collagen present in molluscs, and indeed all phyla from the Porifera upwards, may represent an ancestral collagen molecule conserved relatively unchanged throughout evolution. Type IX-like collagen seems to be essential for the formation of cartilaginous tissue.

Age-dependent changes in the expression of matrix components in the mouse eye

Although the presence of 'cartilage-specific' collagens in the eye has been documented earlier, very little is known about their synthesis rates during ocular development, growth and aging. The purpose of the present study was to follow changes in the mRNA levels and distribution of key components of the extracellular matrix in the eyes of normal and transgenic Del1 mice, harboring a short deletion mutation in the type II collagen gene, during ocular growth and aging. Total RNAs extracted from mouse eyes were studied by Northern analysis for mRNA levels of type I, II, III, VI, IX and XI collagens, biglycan, fibromodulin and decorin. A predominant finding of the present study was the marked reduction in the mRNA levels of type I and II collagens in the eye upon aging. The changes in the mRNA levels of type III and VI collagen and proteoglycans were smaller. Localization of type II and IX collagen in the eye was performed by immunohistochemistry. Despite the reduction in the type II collagen mRNA levels, immunohistochemistry confirmed widespread distribution of the protein also in aging mouse eyes, suggesting its slow turnover. Although the Del1 mutation caused gradual degenerative lesions in the eyes, the distribution of the protein remained essentially unchanged. The widespread distribution and marked downregulation of type II collagen production in the mouse eye upon aging probably explain the gradual development of degenerative lesions, particularly in the eyes of transgenic Del1 mice, where production of mutant type II collagen chains also contributes to the process.

Type V collagen regulates the assembly of collagen fibrils in cultures of bovine vascular smooth muscle cells

Vascular smooth muscle cells (SMCs), the major cellular constituent of the medial layer of an artery, synthesize the majority of connective tissue proteins, including fibrillar collagen types I, III, and V/XI. Proper collagen synthesis and deposition, which are important for the integrity of the arterial wall, require the antioxidant vitamin C. Vitamin C serves as cofactor for the enzymes prolyl and lysyl hydroxylase, which are responsible for the proper hydroxylation of collagen. Here, the role of type V collagen in the assembly of collagen fibrils in the extracellular matrix (ECM) of cultured vascular SMCs was investigated. Treatment of SMCs with vitamin C resulted in a dramatic induction in the levels of the cell-layer associated pepsin-resistant type V collagen, whereas only a minor induction in the levels of types I and III collagen was detected. Of note, the deposition of type V collagen was accompanied by the formation of striated collagen fibrils in the ECM. Immunohistochemistry demonstrated that type V collagen, but not type I collagen, became masked as collagen fibrils matured. Furthermore, the relative ratio of type V to type I collagen decreased as the ECM matured as a function of days in culture, and this decrease was accompanied by an increase in the diameter of collagen fibrils. Together these results suggest that the masking of type V collagen is caused by its internalization on continuous deposition of type I collagen on the exterior of the fibril. Furthermore, they suggest that type V collagen acts as framework for the initial assembly of collagen molecules into heterotypic fibrils, regulating the diameter and architecture of these fibrils.

Mycophenolate mofetil reduces myofibroblast infiltration and collagen III deposition in rat remnant kidney

BACKGROUND

Myofibroblasts have been shown to play a pivotal role in the synthesis of extracellular matrix components in several animal models of renal fibrosis. The purpose of the present study was to investigate whether mycophenolate mofetil (MMF) reduces interstitial myofibroblast infiltration and collagen III deposition in 5/6 nephrectomized rats.

METHODS

Forty-five Wistar rats underwent 5/6 renal ablation and received by daily oral gavage either vehicle (N = 20) or MMF (N = 25) during the 60 days following surgery. Groups of five treated and five untreated rats were killed at two, four, and eight weeks after subtotal nephrectomy. Four untreated and three treated rats were killed at week 12, one month after treatment withdrawal. At the time of sacrifice, proteinuria, plasma, and urine creatinine were determined. Immunohistochemistry was performed on renal tissue for alpha-smooth muscle actin (alpha-SMA), a cytoskeletal marker of myofibroblasts, for type III collagen, and for proliferating cell nuclear antigen (PCNA). Moreover, in order to study the in vitro effects of MMF on fibroblast proliferation, rat fibroblasts were cultured in the presence or absence of mycophenolic acid (MPA).

RESULTS

At all periods studied, MMF treatment improved renal functional parameters and progressively decreased remnant kidney hypertrophy and glomerular volume increment. Proliferating cells in renal tubules, interstitium, and glomeruli, as well as interstitial myofibroblast infiltration and interstitial type III collagen deposition, were also significantly reduced by MMF treatment. In addition, MPA exhibited a dose-dependent inhibitory effect on in vitro proliferation of rat fibroblasts.

CONCLUSION

Reduction of interstitial myofibroblast infiltration may be an important event by which MMF significantly prevents renal injury following subtotal renal ablation. Thus, our results suggest that MMF could be useful to limit the progression of chronic renal disease toward end-stage renal failure.

Serum laminin and type IV collagen are accurate markers of histologically severe alcoholic hepatitis in patients with cirrhosis

BACKGROUND/AIMS

Severe alcoholic hepatitis occurs mainly in patients with cirrhosis, and has a high death rate. Corticosteroid therapy has been particularly advocated as reducing mortality in patients with severe histologic lesions. However, identification of these patients is difficult, requiring transvenous liver biopsy. Extracellular matrix serum markers have been proposed as non-invasive diagnostic tools in alcoholic liver disease. The aim of this study was to determine the accuracy of 5 extracellular matrix serum markers, i.e. laminin (Lam), N-terminal peptide of type III procollagen (PIIINP), type I (CI), type III (CIII) and type IV (CIV) collagens in identifying patients with severe histologic alcoholic hepatitis from among those with cirrhosis and suspected alcoholic hepatitis.

METHODS

We studied 80 consecutive patients with alcoholic cirrhosis and clinical suspicion of alcoholic hepatitis referred for transvenous liver biopsy. Clinical severity of alcoholic hepatitis was assessed according to Maddrey's score. Histological severity was scored using the sum of the 3 following items: polynuclear infiltration (0-3); hepatocytes alterations (0-3); Mallory bodies (0-2). According to this score, patients were divided into 3 groups: mild (1-3), moderate (4-6), and severe (7-8) alcoholic hepatitis. Serum levels of the 5 extracellular matrix serum markers were measured at the time of biopsy using radioimmunoassays. Diagnostic value for histologically severe alcoholic hepatitis of the 5 extracellular matrix serum markers was assessed using receiver operating characteristic curves.

RESULTS

Histological alcoholic hepatitis was present in 67 patients (mean alcoholic hepatitis score: 3.4+/-2.3). Maddrey's score was 66% sensitive and 69% specific for the diagnosis of severe histologic alcoholic hepatitis. The serum Lam and CIV concentrations were the most accurate in identifying correctly patients with severe histologic alcoholic hepatitis. At a cut-off of 4.1 UI/ml, Lam was 90% sensitive and 77% specific, whereas at a cut-off of 150 ng/ml, CIV was 89% sensitive and 77% specific. Combination of markers did not result in improved diagnostic value.

CONCLUSION

In patients with cirrhosis, determination of serum Lam or CIV could represent a simple and accurate non-invasive method for identification of patients with histologically severe alcoholic hepatitis eligible for corticosteroid treatment.

Modifications of bone and connective tissue after orthostatic bedrest

Eight male volunteers were submitted to a 6-week anti-orthostatic bedrest trial followed by a 1-month reambulation period. We prospectively monitored whole-body composition by dual-energy X-ray absorptiometry, bone and connective tissue metabolism by biochemical markers and calcium regulating hormones by 1-84 parathyroid hormone and 1,25-dihydroxyvitamin D(3). Bone mineral density (BMD) did not vary significantly; however, a trend toward an increase in head BMD and a decrease in trunk, lumbar vertebrae and lower limb BMD was observed. A decrease in the lower limb lean content occurred by day 27 and was maximum by day 42 after the beginning of bedrest; it normalized by day 30 after bedrest. The serum levels of both osteocalcin and C-terminal crosslinked telopeptide of type I collagen increased as a consequence of bedrest. A slight increase in the serum levels of the N-terminal propeptide of type III collagen, a marker of connective tissue metabolism, was observed during the bedrest period. Except for the C-terminal extension propeptide of type I collagen, all markers decreased to baseline pre-immobilization levels during the 1-month recovery phase. Serum PTH and 1,25-dihydroxyvitamin D(3) levels were low during the bedrest period and rose during the reambulation phase. These results seem to reflect early changes in bone and connective tissue metabolism as a result of bedrest unloading, but their order of magnitude remains moderate, thus emphasizing the necessity to perform longer-duration trials.

Immunohistochemical study of collagens of the extracellular matrix in cartilage of Sepia officinalis

We used various anti-collagen antibodies to perform indirect immunofluorescent staining of cartilage sections from cuttlefish (S. officinalis). On ultrathin sections and collagen fibril preparations from the same tissue, we performed immunostaining with colloidal gold. The extracellular matrix (ECM) of S. officinalis cartilage reacted intensely and homogeneously with an antibody directed against type I-like collagen isolated from the cartilage of cuttlefish and with anti-rat type V collagen antibody. A weak reaction was observed with anti-fish and anti-chicken type I collagen antibodies, while no reaction was observed with anti-rat type I and anti calf type II collagen antibodies. Anti-chicken type II, anti calf type IX and type XI collagen antibodies reacted weakly with ECM, while stained cell bodies and cell processes reacted more intensely. A similar pattern of reaction was observed on cartilage section and isolated collagen fibrils prepared for electron microscopy. These findings suggest that ECM of cuttlefish cartilage may be composed of molecules similar to the type I, type V, type IX and type XI collagen molecules of vertebrates. Cephalopods have evolved a cartilage of structure and macromolecular organisation similar to that of vertebrate cartilage. However, the main molecular components of S. officinalis cartilage--type I-like and type V collagens--differ from those of vertebrate cartilage. We suggest that this type I-like collagen can be considered an initial step toward the evolution of type II collagen typical of vertebrates.

Effect of calcitonin on bone and connective tissue metabolism in hemiplegic patients: a two-year prospective study

OBJECTIVES

To test the effects of 200 IU/day of a nasal spray of salmon calcitonin in modulating the increased bone tissue metabolism observed in hemiplegic patients.

DESIGN

A two-year, prospective, randomized, double-blind, placebo-controlled study.

PATIENTS

Thirty-four patients with hemiplegia due to a cerebrovascular accident were included in the study during the first month after onset of hemiplegia after giving their informed consent. All patients followed a suitably planned course of active rehabilitation according to Bobath. They were randomly allocated to either the calcitonin or the placebo group but all of them received a daily oral calcium supplementation of 1000 mg.

RESULTS

Biochemical markers of bone formation, serum total alkaline phosphatase, osteocalcin and type I procollagen did not vary during the two years of follow-up. Cross-linked carboxy-terminal telopeptide of type I collagen, a biochemical marker of bone resorption, was elevated initially after stroke and then decreased significantly (p <0.001), stabilizing as of month 12. Urinary calcium/creatinine and total hydroxyproline/creatinine ratios presented with similar profiles. The serum levels of the type III procollagen, a marker of connective tissue metabolism, were also elevated upon entry and decreased thereafter. No significant difference could be found between the calcitonin-treated and the placebo group for any of the biochemical markers at any time point.

CONCLUSION

This prospective study demonstrated that biochemical markers of bone and connective tissue metabolism were elevated shortly after the occurrence of stroke and then gradually decreased during the first two years after injury. The daily administration of 200 IU of intranasal calcitonin did not influence the levels of these markers.

Relationships between several markers of extracellular matrix turn-over and ultrasonography in human Schistosomiasis mansoni

We measured the concentrations of several serum and urinary fibrosis markers, which are metabolites of extracellular matrix, in schistosomiasis patients to investigate their relationship with the ultrasonographic scoring system and with parasitologic data. This study was conducted in patients with various stages of the disease evaluated by ultrasonography (intestinal disease with no organ involvement, with minor hepatosplenic involvement and with severe disease) and in endemic controls. The level of hyaluronan, which were increased in infected patients compared with controls (P < 0.01), was the only fibrosis marker that correlated with the ultrasonographic score (P = 0.003) and is thus a potential serum marker of schistosomiasis-associated morbidity. Urinary free pyridinoline levels were lower (P < 0.001) in infected patients with fibrosis (score > or = 1) than in nonfibrotic patients. A two-year follow-up of the patients treated with praziquantel showed that type I collagen and hyaluronan decreased during the first year post-treatment, whereas free pyridinolines peaked after 12 months and decreased thereafter.

Replication and extension analyzing the factor structure of Locus of Control scales for substance-abusing behaviors

Two research questions were addressed in this study. First, what are the dimensions of the concept of control orientation with respect to substance-abusing behaviors as measured by Keyson and Janda's 1972 Drinking-related Locus of Control Scale and by an adaptation of that scale developed for users of other drugs. Second, utilizing a large sample of both male and female clients who abused both alcohol and other drugs, how does that dimensional structure differ from the one presented by Donovan and O'Leary in 1978 for male alcoholics at a VA hospital. Since the present sample was a large (N = 542) representative sample of publicly subsidized clients in Missouri, it provided an opportunity to extend earlier work across type of drug abused and sex. Like Donovan and O'Leary we used a principal components analysis with a varimax rotation to examine the dimensions of the 25-item locus of control scales. Like those authors, the analysis for male alcohol users produced a three-factor solution with interpretations resembling their "intrapersonal" and "interpersonal" factors but with a more fully developed third factor interpretable as a fate or luck dimension. These dimensions were apparent for the other groups as well, although the first two factors were reversed for male users of other drugs and the analysis for female alcohol abusers showed a more consistent sociability dimension than for males. While the derived structures are therefore similar to Donovan and O'Leary's results and consistent with the theoretical uses of control orientation in discussion of alcohol and other drug abuse, they also show some differences for type of drug abused and by sex. These are necessary but not sufficient conditions for including such measures in more specific models relating clients' motivation and propensity for change to outcomes.

Biochemical markers of bone metabolism in draught and warmblood horses

Concentrations of the cross-linked carboxyterminal telopeptide of type I collagen (ICTP) and osteocalcin (OC) have been determined in the serum of one hundred clinically healthy adult Draught or Warmblood horses. The correlation between these two markers has been evaluated and the influence of gender, age and type of horse described. No significant variations were observed between animals of different sex, but a significant inverse correlation (P < 0.0001) with age was observed for both measured parameters. After correction for age, serum levels of OC were found to be lower in Draught [adjusted least square mean (LSM) = 6.612 micrograms.L-1] than in Warmblood horses (adjusted LSM = 8.596 micrograms.L-1), whereas levels of ICTP were higher in Draughts (adjusted LSM = 8.035 micrograms.L-1) than in Warmbloods (adjusted LSM = 6.643 micrograms.L-1). A significant correlation (P < 0.0001) was observed between OC and ICTP. This correlation was stronger if the type of horse was taken into account in the statistical model. The ratio OC:ICTP was independent of gender and age. A higher OC:ICTP ratio in Warmbloods compared to the Draught horses might reflect a higher bone remodelling level of horses submitted to regular daily work. It was concluded that ICTP and OC are influenced by the type of horse, and probably reflect a physiological difference in bone remodelling between these animals.

Monitoring of extracellular matrix metabolism and cross-linking in tissue, serum and urine of patients with chromoblastomycosis, a chronic skin fibrosis

BACKGROUND

Chromoblastomycosis is a fungal disease leading to a granulomatous reaction associated with dermal fibrosis.

METHODS

In an attempt to elucidate the mechanisms leading to improvement in the cutaneous lesions after treatment with terbinafine, a new antifungal drug, we analysed collagen content and cross-linking before and at the end of the treatment. The turnover of extracellular matrix was monitored for 1 year by following up serum and urinary metabolites.

RESULTS

The serum levels of type III collagen and its N-terminal propeptide were correlated with the lesion size (P < 0.035) after 4 and 12 months of treatment respectively. After 4 months of treatment, urinary pyridinoline was higher (P = 0.04) in patients whose lesion size was reduced by more than 50% and serum hyaluronan was lower in patients who had lesions active for less than 5 years (P < 0.05). The treatment increased pyridinoline and pentosidine cross-links in the lesions but significantly reduced the collagen content (P = 0.05).

CONCLUSION

This is the first demonstration that, in addition to its fungicidal activity, terbinafine acts in vivo as an antifibrotic drug.

Spatiotemporal patterns of expression of extracellular matrix molecules in the developing and adult rat olfactory system

Using immunocytochemical methods, we have examined extensively the spatial and temporal patterns of expression of three extracellular matrix molecules-laminin, fibronectin, and type IV collagen-in the embryonic, postnatal (days 2 and 11) and adult rat olfactory system. The study started at embryonic day 14 when olfactory fibres and their associated migrating cells course through the nasal mesenchyme. From embryonic day 14 to the adult, a sheet-like pattern of labelling for laminin, fibronectin and type IV collagen was observed along the basal surface of the olfactory epithelium and around the telencephalon. This type of labelling was continuous around the telencephalic vesicle, whereas it appeared disrupted in the basal lamina of the olfactory epithelium to permit exit of the olfactory axons and their associated migrating cells into the mesenchyme. From embryonic day 14 to day 20, punctate labelling for the three molecules studied was observed along the mesenchymal olfactory pathway, the ventral part of the olfactory bulb, the olfactory nerve layer and the presumptive glomerular layer, respectively. By embryonic day 17, the punctate labelling initially detected in the mesenchymal olfactory pathway was replaced by a sheet-like pattern related to the mature basal lamina surrounding the olfactory axon fascicles. Punctate labelling for laminin and type IV collagen persisted in the olfactory nerve layer and around the glomeruli through adult life whereas that of fibronectin declined and disappeared by postnatal day 2. The spatiotemporal distribution of the punctate pattern for laminin, fibronectin and type IV collagen observed in the embryonic olfactory system suggests a role in delineating the pathway for olfactory axon elongation. The continuous expression of laminin and type IV collagen in the adult olfactory bulb may be related to the regenerative activity and high plasticity of the olfactory system.

Development of an ELISA for pantothenic acid (vitamin B5) for application in the nutrition and biological fields

Immunological assays appear to be the only alternative to the microbiological method for analysis of pantothenic acid in foods and blood. In order to evaluate the influence of the linker on the immunogenicity of the hapten, we have tried to raise antisera against pantothenic acid in rabbits using different conjugates. The hapten was coupled to a carrier protein (BSA or thyroglobulin) using adipoyl dichloride (adipoyl conjugate) or bromoacetyl bromide (acetyl conjugate). Only the acetyl conjugate has induced the production of a specific antibody. With this antibody, an assay on microplate using the ELISA inhibition technique was developed to measure pantothenic acid. The use of pantothenic acid coupled to thyroglobulin with adipoyl dichloride as the capture antigen has improved the sensitivity of the ELISA. This assay was applied to food products and blood.

Immunolocalization of type IX collagen in normal and spontaneously osteoarthritic canine tibial cartilage and isolated chondrons

OBJECTIVE

The pericellular localization of type IX collagen in avian and mammalian hyaline cartilages remains controversial, while its distribution during osteoarthritic degeneration is poorly understood. This study aimed to compare and contrast the immunohistochemical distribution of type IX collagen in normal mature and spontaneously osteoarthritic canine tibial cartilage.

DESIGN

Thick vibratome sectioning techniques were evaluated and compared with isolated chondrons using a range of streptavidin-linked probes in combination with light, confocal and transmission electron microscopy.

RESULTS

In normal intact samples, type IX collagen was concentrated in the pericellular microenvironment, while a weaker extracellular reaction around each chondron separated the territorial matrix from the unstained interterritorial matrix. Further differentiation was evident in isolated chondrons where the fibrous pericellular capsule stained more intensely than the tail and interconnecting segments between columnated chondrons. Two regions of type IX reactivity were identified in osteoarthritic tissue: an intensely stained superficial reactive region below the eroding margins, and normal deep layer cartilage where pericellular staining persists. The superficial reactive region was characterized by chondron swelling and chondrocyte cluster formation, a loss of pericellular type IX staining, and a significant increase in matrix staining between clusters. Disintegration and loss of fibrillar collagens was evident in both the swollen microenvironment and adjacent territorial matrices.

CONCLUSIONS

The results suggest that changes in type IX distribution, expansion of the pericellular microenvironment and chondrocyte proliferation represent key elements in the chondron remodeling and chondrocyte cluster formation associated with osteoarthritic degeneration.

Analysis of types I, II, III, IX and XI collagens synthesized by fetal bovine chondrocytes in high-density culture

OBJECTIVE

This study was undertaken in order to determine phenotypic modulation of the chondrocytes more closely in high-density culture conditions and to clarify the role of ascorbate. Levels of five collagen types were analyzed qualitatively and quantitatively, and their distribution was observed in the cell layer and the culture medium.

DESIGN

Types I, II, III, IX and XI collagens, synthesized by fetal bovine chondrocytes in high-density culture, were analyzed qualitatively and quantitatively by direct measurement of radiolabeled collagens separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and by specific radioimmunoassays.

RESULTS

Under the experimental conditions used in this study (0.6 x 10(6) cells/cm2), chondrocytes did not proliferate in the absence of ascorbate, whereas a twofold increase in cell number was observed in the presence of ascorbate at day 14. Cartilage-specific collagens (types II, IX and XI) were synthesized throughout the culture period (up to 47 days), as was type III collagen, which appeared as early as day 1 and was essentially present in the culture medium. Partial dedifferentiation of chondrocytes was demonstrated by the synthesis of type I collagen, which was detected by day 2 in culture medium containing ascorbate, and by day 6 without ascorbate. After 33 days of culture, a threefold increase in type I collagen synthesis was observed in culture medium with ascorbate, reaching 66% of the type II collagen content of the cell layer. One month of culture marked the onset of a progressive decrease in the synthesis of all collagen types.

CONCLUSIONS

Under these high-density culture conditions, fetal bovine chondrocytes undergo a time and ascorbate-dependent program of partial dedifferentiation. This system provides a simple model for studying the initial mechanisms of chondrocytes dedifferentiation.

Processing of type XI collagen. Determination of the matrix forms of the alpha1(XI) chain

Type XI collagen is mainly found as a minor constituent in type II-containing fibrils and presents a alpha1(XI)alpha2(XI)alpha3(XI) stoichiometry. This molecule was shown to be partially processed in its intact tissue form. Moreover, alternative splicing has been demonstrated in the variable region of the N-terminal domain of alpha1(XI) and alpha2(XI) chains. In this work, the processing of a major intact form of alpha1(XI) from matrix laid down by chick chondrocytes in culture was identified using N-terminal sequencing and antibodies to synthetic peptides corresponding to the N-terminal propeptide cDNA-derived sequence. The results show that the fully processed form of alpha1(XI) begins at Gln254 of the N-terminal propeptide, seven residues before the end of the proline/arginine-rich protein region encoded by exon I (Zhidkova, N. I., Justice, S. K., and Mayne, R. (1995) J. Biol. Chem. 270, 9486-9493). This sequence is immediately followed by a sequence encoded by exon III. The processing takes place at an Ala-Gln sequence that corresponds to a consensus sequence for procollagen N-proteinase. The antibody raised against a sequence located within the region corresponding to exon IV (anti-P8) fails to recognize this fully processed form of the alpha1(XI) chain. It recognizes, however, two minor bands of high molecular mass. These results suggest that a major cartilage form of alpha1(XI) is the product of alternative splicing in which sequences encoded by both exons II and IV are skipped. The presence of a highly acidic subdomain encoded by exon III at the N terminus of the major form of the alpha1(XI) chain, as predicted by these data, provides potential sites for interaction of collagen XI with other molecules.

Characterization of crosslinked collagens synthesized by mature articular chondrocytes cultured in alginate beads: comparison of two distinct matrix compartments

We have characterized immunohistochemically and biochemically the collagens accumulating in two compartments of the matrix formed by mature bovine articular chondrocytes in alginate beads. At all times of the 28-day culture period, more than 90% of the collagen molecules were recovered from the rim of cell-associated matrix (CM) which encapsulates individual chondrocytes and chondrocyte clusters. Both the total amount and concentration of collagens in this matrix compartment rose progressively with time. The ratio of collagen/proteoglycan remained relatively constant with time and was always five to seven times higher in the CM than in the interterritorial matrix compartment further removed from the cells. In the CM, collagen types II, IX and XI were present on Day 28 in relative proportions (95/l/3) similar to those in adult cartilage. A higher proportion of newly synthesized collagen type XI than types II or IX molecules did not become incorporated into the pericellular rim of matrix but accumulated in the further removed matrix. Although collagen type I was synthesized in small amounts by flattened cells at the surface of the beads, it did not become incorporated as heterotrimers or homotrimers in the matrix. Mature pyridinium crosslinks, principally pyridinoline, were detected as early as Day 7 of culture but became much more abundant between Days 15 and 28, especially in the CM which contained at all times more than 90% of the crosslinks formed. The codistribution of collagen types II, IX and XI and mature collagen-specific crosslinks support the contention that mature chondrocytes cultured in alginate matrix surround themselves with a protective shell whose composition is very similar to that which encapsulated the cells in vivo.

Highly sensitive immunoradiometric assay for serum thyroglobulin with minimal interference from autoantibodies

Five monoclonal antibodies (MAbs) directed against antigenic domains on thyroglobulin (Tg) not recognized by most anti-Tg human autoantibodies (aAbs) have been used to develop an improved IRMA for serum Tg with a limit of detection of 0.2 micrograms/L. Samples are incubated for 3 h in tubes coated with four anti-Tg MAbs. After washing, the tubes are incubated with the tracer MAb for 20 h at room temperature. Dilution and reproducibility tests demonstrated assay reliability. Tests performed on samples with (n = 361) or without (n = 283) aAbs showed that the TG IRMA Pasteur is largely independent of the marked interference generally caused by aAbs. These results were confirmed with an extended population of 2759 samples. For a cutoff of 1 micrograms/L, sensitivity and specificity were 0.97 and 1, respectively, in a follow-up of differentiated thyroid carcinoma in patients treated by total thyroidectomy.

Highly sensitive immunoradiometric assay for serum thyroglobulin with minimal interference from autoantibodies

Five monoclonal antibodies (MAbs) directed against antigenic domains on thyroglobulin (Tg) not recognized by most anti-Tg human autoantibodies (aAbs) have been used to develop an improved IRMA for serum Tg with a limit of detection of 0.2 micrograms/L. Samples are incubated for 3 h in tubes coated with four anti-Tg MAbs. After washing, the tubes are incubated with the tracer MAb for 20 h at room temperature. Dilution and reproducibility tests demonstrated assay reliability. Tests performed on samples with (n = 361) or without (n = 283) aAbs showed that the TG IRMA Pasteur is largely independent of the marked interference generally caused by aAbs. These results were confirmed with an extended population of 2759 samples. For a cutoff of 1 micrograms/L, sensitivity and specificity were 0.97 and 1, respectively, in a follow-up of differentiated thyroid carcinoma in patients treated by total thyroidectomy.

Ultrastructural Localization of elastin-like immunoreactivity in the extracellular matrix around human small lymphatic vessels

The distribution of elastin-like immunoreactivity around small lymphatic vessels was investigated in three different human tissues (skin, heart and dental pulp) using high resolution immunocytochemistry. Quantitative assessment of the immunogold reaction was performed with an image analysis system. Intense and moderate elastin-immuno-reactivity was detected in the extracellular matrix around small lymphatic vessels of the skin and heart, respectively. By contrast, absence of immunostaining was observed around lymphatic vessels in the dental pulp. Although the staining was mostly detectable on the non-fibrillar amorphous component of the extracellular matrix, some microfibrils were also immunostained in close proximity to the lymphatic vessel wall. These findings support the concept that small lymphatic vessels may be heterogeneous with respect to the composition of the extracellular matrix around their wall. The observation that it is possible to observe small lymphatic vessels displaying low or no elastin-immunoreactivity in the adjoining matrix militates against the hypothesis that elastic fibers play a pivotal role in the mechanisms that regulate the function of small lymphatic vessels.

Imbalance between 95 kDa type IV collagenase and tissue inhibitor of metalloproteinases in sputum of patients with cystic fibrosis

A growing body of evidence suggests that neutrophil-derived proteinases play a major role in lung tissue damage in cystic fibrosis (CF). Most previous studies have focused on serine proteinases such as neutrophil elastase, providing no information on the extent to which metalloproteinases participate in proteolytic processes in CF. To address this issue, we evaluated the contribution of one of the major neutrophil metalloproteinases, i.e., 95 kDa gelatinase (type IV collagenase), to the total gelatinolytic activity measured in sputum specimens from 27 patients with CF. Compared with asthmatic children (n = 9), CF patients had a 6.7 times greater level of total gelatinase activity in sputum revealed by zymography. The 95 kDa gelatinase was increased 3.7-fold in the CF subjects (2,441 +/- 411 [SEM] arbitrary units [AU] x 10(6) per ml of sputum versus 665 +/- 201 in asthmatics) and the 88-kDa active form 23.2-fold (2,272 +/- 372 AU x 10(6) per ml of sputum versus 98 +/- 43, respectively). Using radiolabeled 3H-gelatin as the substrate, we demonstrated uninhibited gelatinolytic activity in all CF patients; this activity was significantly correlated to disease severity as assessed by pulmonary function tests. Western blotting using anti-tissue inhibitor of metalloproteinase (anti-TIMP) and anti-95/88-kDa gelatinase antibodies demonstrated a more than 10-fold excess of 95/88 kDa gelatinase over TIMP. Bacterial proteinases from Pseudomonas aeruginosa were shown to contribute little to the gelatinolytic activity measured in sputum supernatants from patients with CF, although culture supernatants from various P. aeruginosa strains expressed gelatinolytic activity in vitro. Finally, lung damage, as assessed by increased type IV collagen degradation products in sputum, was significantly correlated to concentrations of active 88 kDa gelatinase. These data argue for a significant role of 95/88 kDa gelatinase in airway damage in CF.

Ultrastructural characterization of mesenchymal and epithelial cells co-cultured from human dental root apical explants

Previous studies have shown the role of cell-cell and cell-matrix interactions in the differentiation of the specific secretory cells of the tooth. In order to elucidate the mechanisms implicated in root dentin formation, we developed a co-culture system of human pulpal mesenchymal and epithelial root sheath cells. Root tips of premolars were cultured in Eagle's basal Medium supplemented with fetal calf serum, ascorbic acid, antibiotics and, for some of them, with sodium beta-glycerophosphate. After 60 days of culture, cells were prepared for light and electron microscopy. Three main cell types were observed: (1) polygonal mesenchymal cells showing a functional polarity and producing a dense network of tactoid collagenous fibers. The latter had a specific circular organization that delimited small lacunae around the cells and mineralized in the presence of beta-glycerophosphate; (2) spindle-shaped mesenchymal cells mainly localized inside epithelial-mesenchymal knots and synthesizing an abundant collagenous matrix; and (3) epithelial cells lying on the plastic culture dish, on the dense collagenous matrix, or on spindle-shaped cells. Epithelial cells deposited a structured basement membrane when they were lying on the plastic culture dish or on spindle-shaped cells. On the contrary, no basement membrane was found when epithelial cells were overlying the dense collagenous network. Immunoelectron microscopic analysis of type IV collagen and laminin indicated that these two specific basement membrane components were produced by all cell types. These results show that the co-culture system should be valuable for (1) studying the in vitro formation of human dental root hard tissues, (2) characterizing cell-cell and cell-matrix interactions implicated in dental basement membrane production, and (3) isolating populations of cells implicated in dental root formation.

Qualitative study of collagenous and noncollagenous glycoproteins of the human healthy keratinized mucosa surrounding implants

The purpose of this study was to analyse the distribution of interstitial collagenous and noncollagenous glycoproteins of keratinized mucosa surrounding successful endosseous implants. Biopsies were incubated with highly purified antibodies against types I, III, IV collagen, laminin and fibronectin and routinely observed by immunofluorescence staining. Whereas no significative difference in the distribution of collagenous components was observed in comparison with healthy human gingiva, the collagen fibers of the connective tissue attachment ran parallel to the long axis of the implant. In 50% of the biopsies the gingival connective tissue underlying the junctional epithelium was rich in inflammatory cells and poor in collagenous components. However, the increased staining of type III collagen and the intense presence of fibronectin in this area reflect the very important remodeling ability of the local keratinized mucosa.

Transforming growth factor beta 1 stimulates type V collagen expression in bovine vascular smooth muscle cells

Vascular smooth muscle cells (SMCs) produce the bulk of the connective tissue of major arteries, including collagen types I, III, and V. Recently, we have shown, they also have the capacity to synthesize the alpha 1 chain of type XI, a collagen related to type V (Brown, K., Lawrence, R., and Sonenshein, G. (1991) J. Biol. Chem. 266, 23268-23273). Furthermore, expression of types V and XI collagen were coordinately regulated with respect to serum deprivation and cell density in a fashion distinct from that for types I and III. To begin to determine the factors that influence vascular SMC production of types V/XI collagen, we have examined the effects of transforming growth factor (TGF)-beta 1, a major modulator of connective tissue expression. In serum-deprived confluent cultures of bovine pulmonary artery SMCs, TGF-beta 1 treatment increased the steady-state levels of the mRNAs of collagen types V and XI, as well as of types I and III, elastin and fibronectin. The largest increase was seen for alpha 2(V) procollagen. The increase in alpha 2(V) mRNA was detectable by 12 h after addition of 2 ng/ml TGF-beta 1, and concentrations as little as 0.5 ng/ml were effective. A similar increase in alpha 2(V) mRNA levels was observed with SMCs derived from the aortic arch and carotid artery. Type V collagen protein was found to be elevated by TGF-beta 1 treatment in both the conditioned media and the cell layer associated fraction of pulse-labeled cultures. A slight decrease in SMC proliferation as judged by DNA content, [3H]thymidine incorporation, and steady-state levels of histone H3.2 mRNA resulted from TGF-beta 1 treatment. These results suggest that the elevated levels of TGF-beta 1 in the vessel wall during atherosclerosis may be, in part, responsible for the increase in type V collagen that typifies advanced fibrotic lesions.

The managerial nature of case management

Case managers have been viewed as engaging in direct practice, community practice, or both. This article offers a third view: Case managers also engage in the practice of management. Employing Mintzberg's seminal research on chief executive behavior, the authors argue that case managers' work is similarly characterized by brevity, variety, and fragmentation. Case managers perform the 10 roles developed in Mintzberg's original study. These roles are divided into three groups: interpersonal, including figurehead, leader, and liaison; informational, including monitor, disseminator, and spokesperson; and decision-making, including entrepreneur, disturbance handler, resource allocator, and negotiator. Case managers' tasks associated with each role are presented. Considering their work as managerial in nature will help case managers more effectively assist clients in goal achievement.

The effects of PEG on second antibody immunoprecipitation and its use in immunoassay

The effects of PEG on the second antibody immunoprecipitation have been studied in several radioimmunological systems. The following parameters have been studied in the assays: the average molecular weight and concentration of PEG, the species of the animal producing the first and second antibody, the nature of the antigen, the concentration of carrier immunoglobulins, and the rate of the immunoprecipitation. Thus, optimal conditions for the use of PEG with a second antibody have been defined in order to be used in any liquid phase immunoassay.

Ultrastructural organization of type XI collagen in fetal bovine epiphyseal cartilage

Type XI collagen was localized with polyclonal antibodies specific for alpha 1 (XI) and alpha 2 (XI) chains in the resting zone of epiphyseal cartilage from calf fetuses. The immunofluorescence technique was used on sections of cartilage, and the immunogold labelling technique for electron microscopy on fibrils isolated from cartilage and, for the first time, in situ on blocks of cartilage fractured in liquid nitrogen. Immunofluorescence showed that without pepsin treatment the staining of type XI collagen was restricted to the pericellular zones; after pepsin treatment, the staining was co-distributed with that of type II collagen. Immunoelectron microscopy performed on isolated fibrils and on cartilage blocks showed that after disruption of fibrils with pepsin, type XI collagen was labelled on small filaments on the fibrils. When the fibrils were not disrupted, labelling was observed in situ only at the ends of the fibrils or on cross-sections of some fibrils. These results indicate that type XI collagen is located inside type II collagen fibrils in fetal bovine epiphyseal cartilage, as already postulated for embryonic chicken sterna.

Composition and organization of the collagen network produced by fetal bovine chondrocytes cultured at high density

Fetal bovine chondrocytes isolated from the resting zone of epiphyseal cartilage were maintained in high-density culture for 4 weeks. From Day 2 in culture, the chondrocytes deposited an extracellular matrix composed of Types II, IX, and XI collagen. Types IX and XI collagen were restricted to the pericellular domain from Day 5. By 2 weeks the entire cell layer stained for antibodies to Type II and IX collagens. Type XI could be demonstrated throughout the cell layer by pepsinization of the sections. Results from both rotary shadowing and immunochemistry showed that the fibrils formed in culture were heterotypic, with Type IX collagen arranged along the surface and with Type XI collagen buried in Type II fibrils. Nonspecific Type VI collagen and the glycoproteins tenascin and fibrillin, previously described in cartilaginous tissue, were identified by their ultrastructural characteristics in the cell layer homogenate. Although the cells presented morphological characteristics of chondrocytes and still expressed cartilage-specific collagens, the appearance of Type I collagen in the culture cell layer after 4 weeks of culture demonstrates a partial dedifferentiation of the chondrocytes. The culture system described in this report provides an interesting tool for maintaining chondrocytes in a cartilage-like matrix to study the influence of different physical and chemical factors on the expression and differentiation of the cells.

Four markers of collagen metabolism as possible indicators of disease in the adult respiratory distress syndrome

During the adult respiratory distress syndrome (ARDS), an irreversible fibrotic process can occur extremely rapidly. To establish indices of ARDS in pneumonia as well as the severity of the lung fibrosis, we have undertaken for the first time a study of four markers of collagen metabolism obtained from both bronchoalveolar lavage fluid (BALF) and serum: Type I (CI), Type III (CIII), N-terminal peptide of Type III procollagen (PIIINP), and galactosylhydroxylysylglucosyltransferase activity (GGT). We studied 61 patients (13 coma controls, 29 with pneumonia, and 19 with ARDS). In BALF, the average values of CI, CIII, PIIINP, and GGT were significantly higher in ARDS than in the control patients. The values for patients with pneumonia, although increased, were significantly lower than those in ARDS for CI, CIII, and PIIINP. In serum, the mean CI and PIIINP were significantly increased in pneumonia and ARDS, but the mean CIII was significantly increased only in ARDS compared with the control group. Significant positive linear correlations were observed for ARDS between CI and CIII or PIIINP and CIII in BALF and serum. Such correlations were observed for pneumonia only in serum. Molecular mass determinations demonstrated that CI- and CIII-related antigens in BALF were essentially intact triple helices of collagens or procollagens. Among patients with histologically defined interstitial fibrosis, the level of PIIINP in BALF was significantly higher for those with an additional intraalveolar fibrosis. In conclusion, measurements of these collagen markers may be useful for assessing disease activity and reflecting the flux of collagen molecules in the lung.

[Comparison of six potential serum markers of hepatic fibrosis in alcoholic disease of the liver]

The aim of this study was to compare 6 potential serum markers for hepatic fibrosis in patients with alcoholic liver disease. Ninety-three patients (50 +/- 11 years old, 62 males) with biopsy-proven alcoholic liver disease were included in the study. A liver biopsy and serum assays of type I, type III and type IV collagens, N-terminal peptide of type III procollagen, laminin (by radioimmunoassays) and apolipoprotein A1 (by nephelometry) were performed in all patients. A histological score of hepatic fibrosis was established. Alcoholic hepatitis lesions and perisinusoidal fibrosis were assessed separately. A significant correlation was found between the score of hepatic fibrosis and serum levels of type I collagen (r = 0.44, P < 10(-3)), type III collagen (r = 0.36, P < 10(-2)), N-terminal peptide of type III procollagen (r = 0.50, P < 10(-3)), type IV collagen (r = 0.44, P < 10(-3)), laminin (r = 0.50, P < 10(-3)), and apolipoprotein A1 (r = 0.21, P < 0.05). After adjustment for the presence of lesions of alcoholic hepatitis and perisinusoidal fibrosis (partial correlation), serum levels of type I collagen, type III collagen, N-terminal peptide of type III procollagen, type IV collagen, and laminin remained significantly correlated with the score of hepatic fibrosis; in contrast, correlation with serum apolipoprotein A1 was no longer significant. Serum levels of N-terminal peptide of type III procollagen, type IV collagen and laminin were significantly higher in patients with perisinusoidal fibrosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Inpatient and outpatient outcomes in Missouri's alcohol and drug treatment programs

A comparison of the effectiveness of inpatient and outpatient services for alcohol and drug clients is presented. Controls for program completion and severity of substance use on entry to treatment are included. While inpatients do only as well as outpatients overall, inpatient services show significant advantage for particular classes of clients. Results, though preliminary, suggest that the recent call for a cutback in inpatient services is premature.

The human rhabdomyosarcoma cell line A204 lays down a highly insoluble matrix composed mainly of alpha 1 type-XI and alpha 2 type-V collagen chains

The biosynthesis of collagen by the A204 cell line was examined using polyclonal antibodies raised against collagen type V and type XI. The study of the pepsin-digested collagen showed that it is composed mainly of alpha 1(XI) and alpha 2(V) collagen chains in an apparent 2:1 ratio, suggesting the formation of heterotypic molecules [alpha 1(XI)]2 alpha 2(V). The existence of this chain stoichiometry was further demonstrated by immunoprecipitation of the molecule with an antibody recognizing alpha 2(V) but not alpha 1(XI) collagen chains. Electron microscopy analyses of 24-h cultures showed that this matrix is composed of thin fibrils, that can be decorated with immunogold-labelled anti-(type-V collagen) IgG, but not with anti-(type-XI collagen) IgG. The collagen matrix laid down by A204 cells is highly insoluble. In the presence of beta-aminopropionitrile, an inhibitor of lysyl oxidase, only a small proportion of intact collagen could be extracted without proteolytic treatment. Immunoblotting of intact medium collagen from cultures performed in the presence of beta-aminopropionitrile showed four distinct bands with each antibody. The migration of the bands, stained with anti-(type-V collagen) IgG, had apparent molecular masses of 127, 149, 161 and 198 kDa (compared to globular standards) while the bands stained with anti-(type-XI collagen) IgG had apparent masses of 145, 182, 207 and 225 kDa. These data indicate that type-V and type-XI collagen chains can assemble in heterotypic isoforms. In this system, the synthesized isoforms are able to aggregate into a highly cohesive matrix and they undergo a proteolytic processing closely similar to that of other fibrillar collagens.

Two-site direct immunoassay specific for active renin

A sensitive immunoradiometric assay, without an enzymatic step and specific for active human renin, was developed with use of two monoclonal antibodies (MAbs). In this assay system, the first MAb was coupled to magnetic beads (Magnogel); the second one, directed against the active form of the enzyme, was radiolabeled with 125I. The specificity of this assay was demonstrated in experiments measuring the active plasma renin concentration in the presence or absence of inactive renin. The assay, performed in two steps, was sensitive enough to detect 0.9 pg of renin per tube (3.5 ng/L). Intra- or interassay CVs were < 10%. Concentrations of active plasma renin measured in normotensive subjects were between 7 and 40 ng/L.

Two-Site Direct Immunoassay Specific for Active Renin

A sensitive immunoradiometric assay, without an enzymatic step and specific for active human renin, was developed with use of two monoclonal antibodies (MAbs). In this assay system, the first MAb was coupled to magnetic beads (Magnogel); the second one, directed against the active form of the enzyme, was radiolabeled with 125I. The specificity of this assay was demonstrated in experiments measuring the active plasma renin concentration in the presence or absence of inactive renin. The assay, performed in two steps, was sensitive enough to detect 0.9 pg of renin per tube (3.5 ng/L). Intra- or interassay CVs were &lt; 10%. Concentrations of active plasma renin measured in normotensive subjects were between 7 and 40 ng/L.

The role of fibroblasts in dermal vascularization and remodeling of reconstructed human skin after transplantation onto the nude mouse

The vascularization and the dermal remodeling of two different types of human skin reconstructed "in vitro" and grafted onto the nude mouse were studied. They were composed of human keratinocytes grown either on a human acellular deepidermized dermis (DED), or on a lattice composed of human fibroblasts embedded in bovine type I collagen, a living dermal equivalent (LDE). At different stages after grafting, the transplants were harvested and processed for an immunohistological study with species-specific and non-species-specific antibodies. At one month after grafting, the two types of grafted dermis contained blood vessels whose vascular basement membranes were labeled with a mouse-specific anti-type IV collagen antibody. With an antibody specific for human type IV collagen, a constant labeling of the vascular basement membrane was only observed in the LDE containing fibroblasts. In the DED, a constant association of the mouse endothelial cells with human type IV collagen was observed at early stages after grafting. At later stages, the human type IV collagen progressively disappeared. On the other hand, the dermal-epidermal junction underneath the human epidermis contained human type IV collagen in the two types of reconstructed skin. Labeling with the species-specific antibodies directed against human or murine type I collagen showed that the ratio murine type I collagen versus human type I collagen increased with time, suggesting that the DED is progressively invaded by mouse fibroblasts that produce the mouse collagen. On the other hand, in the LDE, the preexisting bovine type I collagen became progressively undetectable while both human type I collagen and elastic fibers were deposited by numerous human fibroblasts. Mouse type I collagen was not detected. Altogether, these observations made by grafting human skin reconstructed "in vitro" onto the nude mouse should be interesting for evaluating the usefulness of grafting a dermal substrate together with the epidermal sheet in the treatment of burns.

Interleukin-1 alpha as a potent inhibitor of gonadotropin action in porcine Leydig cells: site(s) of action

The effects of interleukin on testicular steroidogenesis have been studied in several laboratories, most often by using cultured rat Leydig cells. Several reports have indicated that interleukin-1 beta (IL-1 beta), but not interleukin-1 alpha (IL-1 alpha), exert a potent effect on gonadotropin action in rat Leydig cells. By using cultured porcine Leydig cells as a model, we found that IL-1 alpha (and to a lesser extent IL-1 beta), contrary to previous reports, is a potent inhibitor of LH/hCG steroidogenic action; and we further localized the steroidogenic biochemical step(s) affected by IL-1 alpha. IL-1 alpha inhibited hCG-induced testosterone secretion (about 67%) in a dose- and time-dependent manner. Half maximal and maximal effects were obtained with 4 U/ml (approximately 0.4 ng/ml, 0.3 x 10(-10) M) and 20 U/ml (approximately 2 ng/ml, 1.4 x 10(-10) M) of IL-1 alpha, respectively. The inhibitory effect of IL-1 alpha on gonadotropin action was detected at 6 h and was maximal after 24 h of treatment with the cytokine. The IL-1 alpha inhibitory effect was more potent than that of IL-1 beta: the maximal inhibitory effect of IL-1 beta was obtained with 400 U/ml. Subsequent investigations indicated that IL-1 alpha inhibited different biochemical steps involved in gonadotropin-induced testicular steroidogenesis. In this context, although IL-1 alpha appears to inhibit Leydig cell membrane functions (through a decrease in LH/hCG binding and gonadotropin-induced cAMP production), the antigonadotropin action of the cytokine is probably exerted predominantly at a step(s) located beyond cAMP formation.(ABSTRACT TRUNCATED AT 250 WORDS)

Exploration of the relationship between choral singing and successful aging

This paper describes a retirement village community chorus of 49 with the goal of understanding the place of choral activities in the lives of these older people. Group musical activity provides a link to previous satisfying experiences and serves as a preventive measure against alienation. However, the nature of the activity may be consistent with a willingness to give up some inner directedness. Additional research is recommended since the present design with a comparison group of 49 non-choral members did not allow separation of effects of selection from those of activity.

Serum type I collagen and N-terminal peptide of type III procollagen in patients with alcoholic liver disease: relationship to liver histology

This study compared, in patients with alcoholic liver disease, the serum concentration of N-terminal peptide of type III procollagen and of a novel serum marker, type I collagen, with liver histological data and assessed the role of these markers in the diagnosis and follow-up of liver changes. Ninety-six patients (mean age 51 years, 61 men and 35 women) were included. All had alcoholic liver disease diagnosed on usual clinical, biochemical, and histological criteria. Two histological scores, one for alcoholic hepatitis and one for fibrosis, were established. Serum N-terminal peptide of type III procollagen and type I collagen were assayed by liquid phase radioimmunoassay. Significant correlations between serum type I collagen and score of fibrosis (r = 0.34, p less than 0.001) and between serum N-terminal peptide of type III procollagen and score of alcoholic hepatitis (r = 0.60, p less than 0.0001) were noted. There was no significant correlation between serum aminotransferases and the score of alcoholic hepatitis. In 25 patients with alcoholic hepatitis reassessed between 3 and 6 months, serum N-terminal peptide of type III procollagen significantly decreased (p less than 0.05) as did the score of alcoholic hepatitis, but serum type I collagen and the score of fibrosis were not modified. These serum markers of collagen metabolism could be useful for the assessment and follow-up in patients with alcoholic liver disease.

Transforming growth factor beta 1 inhibits gonadotropin action in cultured porcine Sertoli cells

In the present study, we have tested the effects of transforming growth factor beta 1 (TGF beta 1) on FSH action toward aromatase activity and lactate production in cultured Sertoli cells isolated from immature porcine testes. Whereas treatment of Sertoli cells with FSH resulted in a dose-dependent increase (about 7-fold) in aromatase activity (conversion of testosterone into estradiol) (ED50 = 80 ng/ml FSH), the addition of TGF beta 1 reduced this gonadotropin action. The inhibitory effect of TGF beta 1 on FSH aromatase activity was dose dependent (ED50 = 0.1 ng/ml, 4 pM TGF beta 1) with a maximal decrease (about 40%) observed after a long term (48-h) treatment. TGF beta 1 exerted its inhibitory effect on FSH action at the level(s) of cAMP accumulation, exerting no apparent effect on the gonadotropin receptor or at a site(s) related to cAMP action. TGF beta 1 (2 ng/ml) significantly (P less than 0.002) reduced (52% decrease) FSH-stimulated cAMP levels in cultured porcine Sertoli cells. However, such an inhibitory effect of the growth factor was no longer observed when stimulation of cAMP accumulation with FSH occurred in the presence of methyl isobutyl xanthine (0.5 mM), an inhibitor of cAMP-phosphodiesterase activity. This observation suggests that TGF beta 1 decreased cAMP levels by increasing catabolism of the cyclic nucleotide through an enhancement of cAMP-phosphodiesterase activity. The inhibitory effect of TGF beta 1 was not limited to the action of FSH on aromatase activity but also extended to the gonadotropin action (mediated by cAMP) on lactate production. As for the inhibitory effect of TGF beta 1 on FSH-induced aromatase activity, the inhibitory effect of the growth factor on FSH-stimulated lactate production was dose and time dependent with a maximal decrease (about 30%) observed in the picomolar range (1 ng/ml, 40 pM) after 48 h treatment with TGF beta 1. In conclusion, the present study demonstrates that TGF beta 1 attenuates FSH action on Sertoli cell activity and that such inhibitory action is potentially exerted through a decrease in cAMP levels. Because of the local production of TGF beta 1, it is suggested that the effects of the growth factor reported here might be exerted in the context of the testicular paracrine mechanisms.