Family characteristics and behavior problems of suicidal and non-suicidal children and adolescents

The present study examined familial and individual variables in youngsters at high risk for suicide and non-suicidal youngsters. One hundred inpatient children and adolescents completed a battery of questionnaires including, FACES II, Family Strengths, and Problem Behavior Scales, to assess family dysfunction and individual behavior problems. The results indicated that suicidal youngsters have lower pride in their families and perceived them as less adaptable than non-suicidal youngsters as indicated by scores on the Family Strengths and FACES II, respectively. Scores on the Problem Behavior Scales indicated that suicidal youngsters also exhibited self-inflicted behaviors, withdrawal from others, little interest in activities, poor concentration, and difficulties with sleeping. In addition, youths at risk for suicide were more likely to be diagnosed with a mood disorder, including major depressive disorder and dysthymia, as well as substance abuse and phobias. These findings suggest that suicidal youngsters' negative perceptions of their families and their maladaptive behaviors should be given special attention in designing appropriate interventions. In this way, treatment would likely be effective by providing appropriate coping skills and preventing future suicidal attempts in high risk youngsters.

Type X collagen degradation in long-term serum-free culture of the embryonic chick tibia following production of active collagenase and gelatinase

Type X collagen has a very limited distribution during skeletal development in regions of hypertrophic cartilage destined for degradation. In solution assay, type X collagen is degraded to a 32-kDa cleavage product which is resistant to further degradation, suggesting this product may have a function in skeletal development. In this study, we have identified the 32-kDa cleavage product of type X collagen present in the conditioned media (CM) during incubation of isolated 12-day chick tibiae in the absence of serum. In this culture system, chondrocytes throughout the tibial cartilages hypertrophied and deposited type X collagen within their matrix. During culture, the cartilage matrix was degraded in two stages. First proteoglycan was lost followed by degradation of the collagenous components. Collagen degradation was accompanied by the release of active interstitial collagenase and gelatinase into the CM. Purified type X collagen incubated in this CM was cleaved to form a 32-kDa product which was resistant to further degradation. This cleavage product has the same electrophoretic mobility as the 32-kDa chain produced by purified human collagenase.

Late events in chondrocyte differentiation: hypertrophy, type X collagen synthesis and matrix calcification

During endochondral bone formation chondrocytes pass through several stages of differentiation which are characterized by cell proliferation, matrix synthesis and cell hypertrophy. Type X collagen is synthesized in vivo after chondrocytes have become hypertrophic, but before abundant mineral accumulates in the cartilage extracellular matrix. The molecule is also present in the uncalcified membranes of the avian eggshell. Type X collagen synthesis increased with the concentration of calcium phosphate deposited in the cell layer of chondrocyte cultures. The addition of calcium chloride to chondrocyte cultures increased the synthesis of type X collagen in a dose-and time-dependent manner.