Ecosystem change and human health: implementation economics and policy.

Several recent initiatives such as Planetary Health, EcoHealth and One Health claim that human health depends on flourishing natural ecosystems. However, little has been said about the operational and implementation challenges of health-oriented conservation actions on the ground. We contend that ecological-epidemiological research must be complemented by a form of implementation science that examines: (i) the links between specific conservation actions and the resulting ecological changes, and (ii) how this ecological change impacts human health and well-being, when human behaviours are considered. Drawing on the policy evaluation tradition in public economics, first, we present three examples of recent social science research on conservation interventions that affect human health. These examples are from low- and middle-income countries in the tropics and subtropics. Second, drawing on these examples, we present three propositions related to impact evaluation and non-market valuation that can help guide future multidisciplinary research on conservation and human health. Research guided by these propositions will allow stakeholders to determine how ecosystem-mediated strategies for health promotion compare with more conventional biomedical prevention and treatment strategies for safeguarding health.This article is part of the themed issue 'Conservation, biodiversity and infectious disease: scientific evidence and policy implications'.

Correlation of pharmacokinetics with the antitumor activity of Cetuximab in nude mice bearing the GEO human colon carcinoma xenograft.

PURPOSE: The epidermal growth factor receptor (EGFR), a protein tyrosine kinase expressed in many types of human cancers including colon and breast, has been strongly associated with tumor progression. Cetuximab, an IgG1 anti-EGFR chimeric mouse/human monoclonal antibody, has been proven to be effective in the treatment of advanced colon cancer. To date, there has not been a study to systematically evaluate the pharmacokinetics (PK) of Cetuximab in a preclinical model and to further explore any correlation of drug exposure between animal models and cancer patients. In the present study, we characterized the PK of Cetuximab in nude mice at efficacious dose levels and further compared the preclinical optimal dose and active plasma drug concentration with those determined in clinical studies. EXPERIMENTAL DESIGN: The antitumor activity of Cetuximab was evaluated using the GEO human colon carcinoma xenografts implanted subcutaneously in nude mice. The drug was administered ip every 3 days for five total injections (inj) (q3dx5) at dose levels ranging from 1 mg/inj to 0.04 mg/inj. The plasma PK of Cetuximab was determined at dose levels of 1.0, 0.25, and 0.04 mg/inj with a single bolus iv or ip administration in nude mice. The tumoral PK of Cetuximab was determined at dose levels of 0.25, and 0.04 mg/inj with a single bolus ip administration in nude mice bearing GEO tumor xenografts. The plasma and tumoral levels of Cetuximab were quantitated by an ELISA assay. RESULTS: Cetuximab demonstrated a dose-dependent antitumor activity at dose levels of 0.25, 0.1, and 0.04 mg/inj, with a statistically significant tumor growth delay (in reaching a tumor target size of 1 gm) of 18 days (P < 0.001), 12.3 days (P < 0.01), and 10 days (P < 0.01) for 0.25, 0.1, and 0.04 mg/inj, respectively. A separate study employing the same treatment schedule showed that Cetuximab was equally active at dose levels ranging from 0.25 mg/inj to 1 mg/inj. Therefore, dose levels of Cetuximab from 1 mg/inj to 0.04 mg/inj can be considered to be within the efficacious range, while dose levels of 0.25 mg/inj or higher appeared to be optimal for the antitumor activity of Cetuximab in the GEO tumor model. When Cetuximab was given iv to mice, the elimination half life (t(1/2)) was 39.6, 37.8, and 42.2 h for doses of 1.0, 0.25, and 0.04 mg/inj, respectively, suggesting a similar disposition kinetics of Cetuximab within this dose range. The volume of distribution (V(d)) ranged from 0.062 l/kg to 0.070 l/kg, suggesting that Cetuximab is primarily confined to the plasma compartment with limited peripheral tissue distribution. Clearance (CL) was similar and no apparent PK saturation was observed across the dose ranging from 0.04 mg/inj to 1.0 mg/inj. When mice were administered with a single bolus ip administration at doses of 1, 0.25, and 0.04 mg/inj, the maximum plasma concentration (C(max)) was 407.6, 66.4, and 16.5 microg/ml. The area under the curve of plasma drug concentration (AUC) was 19212.4, 3182.4, and 534.5 microg/ml h, for 1.0, 0.25, and 0.04 mg/inj, respectively. The average steady state plasma concentration (C(ss avg)) for the multiple dosing schedule was estimated to be 73.1 microg/ml at 0.25 mg/inj and was considered as an active plasma drug concentration. The maximum tumoral concentration of Cetuximab was 2.6 and 0.53 ng/mg-tumor while the tumoral drug exposure was 112.6 and 18.3 ng/mg h for 0.25 and 0.04 mg/inj, respectively. The EGFR was estimated to be nearly completely occupied by Cetuximab at the optimal dose of 0.25 mg/inj. CONCLUSION: In the present study, we compared the preclinical optimal dose and the corresponding active plasma concentration determined in mice with those being observed in cancer patients, i.e. 65-100 microg/ml. The preclinical optimal dose of 0.25 mg/inj was significantly lower than the current clinical dose. However, the active plasma concentration at 0.25 mg/inj is within the range of the active drug concentrations in cancer patients treated with Cetuximab under the current optimal dosing regimen. It appears that the active plasma drug concentration determined in preclinical model predicts better than the optimal preclinical dose for the clinical development of antibody drugs.

Inhibition of angiogenesis and metastasis in two murine models by the matrix metalloproteinase inhibitor, BMS-275291.

BMS-275291 is an p.o. bioavailable, sulfhydryl-based matrix metalloproteinase (MMP) inhibitor currently in clinical development for the treatment of cancer. This inhibitor was designed to potently inhibit MMP activities while minimally affecting those of other metalloproteases (e.g., sheddases) involved in the release of cell-associated molecules such as tumor necrosis factor-alpha, tumor necrosis factor-alpha receptor, interleukin-6 receptor, or L-selectin. In vitro, BMS-275291 is a potent inhibitor (nM) of the activities of MMP-1, MMP-2, MMP-7, MMP-9, and MMP-14. BMS-275291 inhibits tumor growth in a B16BL6 model of experimental metastasis, and in this model, BMS-275291 treatment results in a dose-dependent reduction in the number of lung metastases compared with vehicle controls. BMS-275291 also inhibits angiogenesis in a murine angiogenesis model, where once daily treatment with BMS-275291 results in a dose-dependent inhibition of endothelial cell migration into s.c. implanted Matrigel plugs. Pharmacokinetic studies demonstrated that the plasma concentrations of parent BMS-275291 in mice exceeds the in vitro IC(50) values for MMP-1, MMP-2, MMP-7, MMP-9, and MMP-14 for at least 4 h after the administration of a therapeutic dose of BMS-275291. Taken together, these data demonstrate that BMS-275291 inhibits MMP activities that contribute to tumor metastasis and angiogenesis.

Preclinical antitumor activity of BMS-214662, a highly apoptotic and novel farnesyltransferase inhibitor.

BMS-214662 is a potent and selective inhibitor of farnesyltransferase (FTI). In rodent fibroblasts transformed by oncogenes, BMS-214662 reversed the H-Ras-transformed phenotype but not that of K-Ras or other oncogenes. In soft agar growth assays, BMS-214662 showed good potency in inhibiting H-ras-transformed rodent cells, A2780 human ovarian carcinoma tumor cells, and HCT-116 human colon carcinoma tumor cells. Inhibition of H-Ras processing in HCT-116 human colon tumor cells was more rapid than in H-Ras-transformed rodent fibroblast tumors. BMS-214662 is the most potent apoptotic FTI known and demonstrated broad spectrum yet robust cell-selective cytotoxic activity against a panel of cell lines with diverse histology. The presence of a mutant ras oncogene was not a prerequisite for sensitivity. Athymic and conventional mice were implanted s.c. with different histological types of human and murine tumors, respectively. BMS-214662 was administered both parenterally and p.o. and was active by all these routes. Curative responses were observed in mice bearing staged human tumor xenografts including HCT-116 and HT-29 colon, MiaPaCa pancreatic, Calu-1 lung, and EJ-1 bladder carcinomas. A subline of HCT-116, HCT-116/VM46, resistant to many standard cytotoxic agents by means of a multiple drug resistance mechanism, remained quite susceptible to BMS-214662, and borderline activity was achieved against N-87 human gastric carcinoma. Two murine tumors, Lewis lung carcinoma and M5076 sarcoma, were insensitive to the FTI. In a study performed using Calu-1 tumor-bearing mice, no obvious schedule dependency of BMS-214662 was observed. The FTI, BMS-214662, demonstrated broad spectrum activity against human tumors, but murine tumors were not as sensitive.

Identification of essential acidic residues of outer membrane protease OmpT supports a novel active site.

Escherichia coli outer membrane protease OmpT has previously been classified as a serine protease with Ser(99) and His(212) as active site residues. The recently solved X-ray structure of the enzyme was inconsistent with this classification, and the involvement of a nucleophilic water molecule was proposed. Here, we substituted all conserved aspartate and glutamate residues by alanines and measured the residual enzymatic activities of the variants. Our results support the involvement of a nucleophilic water molecule that is activated by the Asp(210)/His(212) catalytic dyad. Activity is also strongly dependent on Asp(83) and Asp(85). Both may function in binding of the water molecule and/or oxyanion stabilization. The proposed mechanism implies a novel proteolytic catalytic site.

Crystal structure of the outer membrane protease OmpT from Escherichia coli suggests a novel catalytic site.

OmpT from Escherichia coli belongs to a family of highly homologous outer membrane proteases, known as omptins, which are implicated in the virulence of several pathogenic Gram-negative bacteria. Here we present the crystal structure of OmpT, which shows a 10-stranded antiparallel beta-barrel that protrudes far from the lipid bilayer into the extracellular space. We identified a putative binding site for lipopolysaccharide, a molecule that is essential for OmpT activity. The proteolytic site is located in a groove at the extracellular top of the vase-shaped beta-barrel. Based on the constellation of active site residues, we propose a novel proteolytic mechanism, involving a His-Asp dyad and an Asp-Asp couple that activate a putative nucleophilic water molecule. The active site is fully conserved within the omptin family. Therefore, the structure described here provides a sound basis for the design of drugs against omptin-mediated bacterial pathogenesis. Coordinates are in the Protein Data Bank (accession No. 1I78)

Psychosocial and risk behavior correlates of youth suicide attempts and suicidal ideation.

OBJECTIVE: To identify the independent psychosocial and risk behavior correlates of suicidal ideation and attempts. METHOD: The relationships between suicidal ideation or attempts and family environment, subject characteristics, and various risk behaviors were examined among 1,285 randomly selected children and adolescents, aged 9 through 17 years, of whom 42 (3.3%) had attempted suicide and 67 (5.2%) had expressed suicidal ideation only. The youths and their parents were enumerated and interviewed between December 1991 and July 1992 as part of the NIMH Methods for the Epidemiology of Child and Adolescent Mental Disorders (MECA) Study. RESULTS: Compared with subjects with suicidal ideation only, attempters were significantly more likely to have experienced stressful life events, to have become sexually active, to have smoked more than one cigarette daily, and to have a history of ever having smoked marijuana. After adjusting for sociodemographic characteristics, a statistically significant association was found between suicidal ideation or attempt and stressful life events, poor family environment, parental psychiatric history, low parental monitoring, low instrumental and social competence, sexual activity, marijuana use, recent drunkenness, current smoking, and physical fighting. Even after further adjusting for the presence of a mood, anxiety, or disruptive disorder, a significant association persisted between suicidal ideation or attempts and poor family environment, low parental monitoring, low youth instrumental competence, sexual activity, recent drunkenness, current smoking, and physical fighting. CONCLUSION: Low parental monitoring and risk behaviors (such as smoking, physical fighting, alcohol intoxication, and sexual activity) are independently associated with increased risk of suicidal ideation and attempts, even after adjusting for the presence of psychiatric disorder and sociodemographic variables.

Substrate specificity of the integral membrane protease OmpT determined by spatially addressed peptide libraries.

Escherichia coli outer membrane protease T (OmpT) is an endopeptidase that specifically cleaves between two consecutive basic residues. In this study we have investigated the substrate specificity of OmpT using spatially addressed SPOT peptide libraries. The peptide acetyl-Dap(dnp)-Ala-Arg/Arg-Ala-Lys(Abz)-Gly was synthesized directly onto cellulose membrane. The peptide contained the aminobenzoyl (Abz) fluorophore, which was internally quenched by the dinitrophenyl (dnp) moiety. Treatment of the SPOT membrane with the small, water-soluble protease trypsin resulted in highly fluorescent peptide SPOTs. However, no peptide cleavage was observed after incubation with detergent-solubilized OmpT, a macromolecular complex with an estimated molecular mass of 180 kDa. This problem could be solved by the introduction of a long, polar polyoxyethylene glycol linker between the membrane support and the peptide. Peptide libraries for the P(2), P(1), P(1)', and P(2)' positions in the substrate were screened with OmpT, and peptides of positive SPOTs were resynthesized and subjected to kinetic measurements in solution. The best substrate Abz-Ala-Lys-Lys-Ala-Dap(dnp)-Gly had a turnover number k(cat) of 40 s(-)(1), which is 12-fold higher than the starting substrate. Peptides containing an acidic residue at P(2) or P(2)' were not substrates for OmpT, suggesting that long-range electrostatic interactions are important for the formation of the enzyme-substrate complex. OmpT was highly selective toward L-amino acids at P(1) but was less so at P(1)' where a peptide with D-Arg at P(1)' was a competitive inhibitor (K(i) of 19 microM). An affinity chromatography resin based on these findings was developed, which allowed for the one-step purification of OmpT from a bacterial lysate. The implications of the determined consensus substrate sequence (Arg/Lys)/(Arg/Lys)-Ala for the proposed biological function of OmpT in defense against antimicrobial peptides are discussed.

BMS-247550: a novel epothilone analog with a mode of action similar to paclitaxel but possessing superior antitumor efficacy.

BMS-247550, a novel epothilone derivative, is being developed by Bristol-Myers Squibb Company (BMS) as an anticancer agent for the treatment of patients with malignant tumors. BMS-247550 is a semisynthetic analogue of the natural product epothilone B and has a mode of action analogous to that of paclitaxel (i.e., microtubule stabilization). In vitro, it is twice as potent as paclitaxel in inducing tubulin polymerization. Like paclitaxel, BMS-247550 is a highly potent cytotoxic agent capable of killing cancer cells at low nanomolar concentrations. Importantly, BMS-247550 retains its antineoplastic activity against human cancers that are naturally insensitive to paclitaxel or that have developed resistance to paclitaxel, both in vitro and in vivo. Tumors for which BMS-247550 demonstrated significant antitumor activity encompass both paclitaxel-sensitive and -refractory categories, i.e., (a) paclitaxel-resistant: HCT116/VM46 colorectal (multidrug resistant), Pat-21 breast and Pat-7 ovarian carcinoma (clinical isolates; mechanisms of resistance not fully known), and A2780Tax ovarian carcinoma (tubulin mutation); (b) paclitaxel-insensitive: Pat-26 human pancreatic carcinoma (clinical isolate) and M5076 murine fibrosarcoma; and (c) paclitaxel sensitive: A2780 ovarian, LS174T, and HCT116 human colon carcinoma. In addition, BMS-247550 is p.o. efficacious against preclinical human tumor xenografts grown in immunocompromised mice or rats. Schedule optimization studies indicate that BMS-247550 is efficacious when administered frequently (every 2 days x 5) or intermittently (every 4 days x 3 or every 8 days x 2). These efficacy data demonstrate that BMS-247550 has the potential to surpass Taxol in both clinical efficacy and ease of use (i.e., less frequent treatment schedule and/or oral administration).

Risk behavior in a community sample of children and adolescents.

OBJECTIVES: First, to investigate whether there is covariation between risk behaviors, including suicidality, in a community probability sample of children and adolescents; and second, to investigate whether risk behavior is associated with selected potential correlates. METHOD: A sample of 9- to 17-year-old youths (N = 1,285) and their caretakers were interviewed in the Methods for the Epidemiology of Child and Adolescent Mental Disorders (MECA) Study. The risk behaviors were marijuana smoking, alcohol use, intercourse, fighting, cigarette smoking, and suicidal ideation/attempts. Relationships between the risk behaviors were described using odds ratios. Linear regression analyses of an index of risk behavior on the selected potential correlates of risk behavior were conducted. RESULTS: There were significant relationships between all pairs of risk behaviors. The score on the index of risk behavior was associated with stressors, lack of resources, family psychiatric disorder, psychopathology, and functional impairment. CONCLUSIONS: Clinicians should be alerted to the possibility of risk behaviors, especially in children and adolescents engaging in other risk behaviors and those with inadequate resources, stressors, functional impairment, or psychopathology.

Identification of active site serine and histidine residues in Escherichia coli outer membrane protease OmpT.

Escherichia coli outer membrane protease OmpT has been characterised as a serine protease based on its inhibitor profile, but serine protease consensus sequences are absent. By site-directed mutagenesis we substituted all conserved serines and histidines. Substitution of His(101) and His(212) by Ala, Asn or Gln resulted in variant enzymes with 0.01 and 9-20% residual enzymatic activity towards a fluorogenic pentapeptide substrate, respectively. The mutations S140A and S201A did not decrease activity, while variants S40A and S99A yielded 0.5 and 0.2% residual activities, respectively. When measured with a dipeptide substrate the variant S40A demonstrated full activity, whereas variant S99A displayed at least 500-fold reduced activity. We conclude that Ser(99) and His(212) are essential active site residues. We propose that OmpT is a novel serine protease with Ser(99) as the active site nucleophile and His(212) as general base.

In vitro folding, purification and characterization of Escherichia coli outer membrane protease ompT.

OmpT is a protease present in the outer membrane of Escherichia coli. The enzyme was overexpressed without its signal sequence in E. coli using a T7 system, resulting in the accumulation of OmpT as inclusion bodies. After solubilization of the inclusion bodies in urea, the protein could be folded in vitro by dilution in the presence of detergent n-dodecyl-N, N-dimethyl-1-ammonio-3-propanesulphonate. The addition of lipopolysaccharide to the protein was essential to obtain active enzyme. The correctly folded protein was purified to homogeneity by ion exchange chromatography with a 57% overall yield. Autoproteolysis between Lys217-Arg218 was a major problem during purification, but degradation could be abolished by introducing the mutations G216K and K217G. A novel fluorimetric assay using the internally quenched substrate Abz-Ala-Arg-Arg-Ala-Tyr(NO2)-NH2 (where Abz is o-aminobenzoyl and Tyr(NO2) is 3-nitrotyrosine) enabled the determination of the kinetic parameters. The wild-type enzyme has an affinity Km of 0.4 microM for the substrate and a turnover number kcat of 40 s-1. The Km and kcat for the double variant were 1.1 microM and 1.6 s-1, respectively. The pH profiles of the wild type and variant were identical, showing optimal activity at pH 6.5 and pKa values of 5.6 and 7.5, respectively. Circular dichroism spectra of both enzymes indicated a high content of beta-strand conformation, and on that basis a beta-barrel topology model is proposed.

Characterization of kringle domains of angiostatin as antagonists of endothelial cell migration, an important process in angiogenesis.

Angiogenesis is a complex process that involves endothelial cell proliferation, migration, basement membrane degradation, and neovessel organization. Angiostatin, consisting of four homologous triple-disulfide bridged kringle domains, has previously been shown to exhibit profound inhibition of endothelial cell proliferation in vitro and angiogenesis in vivo. It was also demonstrated that angiostatin could suppress the growth of a variety of tumors via the blocking of angiogenesis. The primary aim of our study was to characterize the kringle domains of angiostatin for their inhibitory activities of endothelial cell migration in order to elucidate their contributions to the anti-angiogenic function of angiostatin. In this report, we demonstrate for the first time that the kringles of angiostatin play different roles in inhibiting endothelial cell migration, a crucial process in angiogenesis. Kringle 4, which has only marginal anti-proliferative activity, is among the most potent fragments in inhibiting endothelial cell migration (IC50 of approximately 500 nM). In contrast, kringle 1-3, which is equivalent to angiostatin in inhibiting endothelial cell proliferation, manifests only a modest anti-migratory effect. The combination of kringle 1-3 and kringle 4 results in an anti-migratory activity comparable to that of angiostatin. When kringle 1 is removed from kringle 1-3, the resulting kringle 2-3 becomes more potent than kringle 1-3. This implies that kringle 1, although virtually ineffective in inhibiting endothelial cell migration, may influence the conformation of kringle 1-3 to alter its anti-migratory activity. We also show that disruption of the kringle structure by reducing/alkylating agents markedly attenuates the anti-migratory activity of angiostatin, demonstrating the significance of kringle conformation in maintaining the anti-angiogenic activity of angiostatin. Our data suggest that different kringle domains may contribute to the overall anti-angiogenic function of angiostatin by their distinct anti-migratory activities.

Cutinase binding and activity at the triolein-water interface monitored by oil drop tensiometry.

Changes of the oil-water interfacial tension resulting from binding of Fusarium solani pisi cutinase and subsequent lipid hydrolysis were investigated using the oil drop technique. An ELISA was developed to determine the amount of cutinase bound to the triolein-water interface after biotinylation of the enzyme. Cutinase irreversibly adsorbs to a maximum value of about 2 mg/m2. A minimal specific activity of 110 mumol/min/mg was calculated for cutinase acting on a single oil droplet, which is close to the activity found for triglyceride emulsions. At a maximum surface load cutinase could generate one monolayer of fatty acid products per second at the interface. It was found that oleic acid rapidly dissolves into the oil phase under the conditions used. The interfacial tension measured reflects the adsorption of cutinase to the oil droplet and also responds to the fate of the hydrolysis products. A model is presented that describes the catalytic events at the oil-water interface during lipid hydrolysis.

Selective inhibition by kringle 5 of human plasminogen on endothelial cell migration, an important process in angiogenesis.

Angiogenesis is a multi-step process that includes endothelial cell proliferation, migration, basement membrane degradation, and new lumen organization. Angiostatin, an internal fragment of plasminogen comprising the first four triple disulfide-linked kringle structures, is one of the most potent endogenous angiogenesis inhibitors described to date. The kringle 5 domain of plasminogen, which shares high sequence homology with the four kringles of angiostatin, was previously shown to antagonize endothelial cell growth. We now describe that the recombinant kringle 5 of human plasminogen inhibits endothelial cell migration with an IC50 (concentration for half maximal inhibition) of approximately 500 nM. We demonstrate that the lysine-binding sites of kringle 5 may not be involved in its anti-migratory activities. The anti-migratory activity of kringle 5 is similar to that of angiostatin. Kringle 5 also shows selective inhibition on endothelial cells as opposed to other cell types. Relative to its native form, reduced kringle 5 displays a significant increase in anti-migratory activity, implying that the kringle conformation may shield kringle 5 from effectively interacting with endothelial cells. This report thus constitutes the first demonstration that kringle 5 of plasminogen is a selective inhibitor for endothelial cell migration.

General medical problems among the offspring of depressed parents: a 10-year follow-up.

OBJECTIVE: To examine the association between both parental and offspring depression and the general medical problems of a sample of offspring at high and low risk for depression. METHOD: Offspring (n = 222) from families with either depressed or nondepressed parents were followed up for a period of 10 years. Data collected included psychiatric diagnoses derived from direct semistructured interviews and history of general medical problems and hospital visits. Rates of medical problems and hospitalizations were calculated, and offspring were stratified by depression status of both parent and offspring. RESULTS: In analyses controlled for sociodemographic factors, offspring depression status was associated with a history of genitourinary disorders, headaches, respiratory disorders, other disorders, and hospitalizations in the offspring, and parental depression was associated with a history of unconsciousness and hospitalization in the offspring. After subjects were stratified by parental depression, significant associations between offspring depression and medical problems were found for only those offspring with a depressed parent. CONCLUSIONS: These findings suggest that a history of parental depression increases the risk for medical problems and hospitalization among depressed offspring. The co-occurrence of general medical and psychological problems among offspring of depressed parents may have implications for the treatment of both depression and comorbid medical disorders.

The mechanism of cancer-mediated conversion of plasminogen to the angiogenesis inhibitor angiostatin.

Angiostatin, a potent naturally occurring inhibitor of angiogenesis and growth of tumor metastases, is generated by cancer-mediated proteolysis of plasminogen. Human prostate carcinoma cells (PC-3) release enzymatic activity that converts plasminogen to angiostatin. We have now identified two components released by PC-3 cells, urokinase (uPA) and free sulfhydryl donors (FSDs), that are sufficient for angiostatin generation. Furthermore, in a defined cell-free system, plasminogen activators [uPA, tissue-type plasminogen activator (tPA), or streptokinase], in combination with one of a series of FSDs (N-acetyl-L-cysteine, D-penicillamine, captopril, L-cysteine, or reduced glutathione] generate angiostatin from plasminogen. An essential role of plasmin catalytic activity for angiostatin generation was identified by using recombinant mutant plasminogens as substrates. The wild-type recombinant plasminogen was converted to angiostatin in the setting of uPA/FSD; however, a plasminogen activation site mutant and a catalytically inactive mutant failed to generate angiostatin. Cell-free derived angiostatin inhibited angiogenesis in vitro and in vivo and suppressed the growth of Lewis lung carcinoma metastases. These findings define a direct mechanism for cancer-cell-mediated angiostatin generation and permit large-scale production of bioactive angiostatin for investigation and potential therapeutic application.

Correlates of unmet need for mental health services by children and adolescents.

BACKGROUND: Little is known about the extent and correlates of unmet need for mental health services in community samples of children and adolescents. METHODS: Data were obtained from the 1285 parent/youth pairs interviewed at four sites in the USA and Puerto Rico in the Methods for the Epidemiology of Child and Adolescent Mental Disorders (MECA) Study. Unmet need was defined to exist if psychopathology and associated functional impairment were present but no mental health services had been received in the previous 6 months. RESULTS: Of the total sample, 17.1% had unmet need. Adjusting for demographic variables, logistic regression analyses revealed that unmet need was significantly associated with: indicators of economic disadvantage, such as being on public assistance and not being covered by health insurance; opinions of the parents and children or adolescents that the latter had poor mental health; parental psychopathology; poor school grades; and parent-reported access barriers such as concern that the child would want to solve the problem unassisted, would refuse to attend mental health services, or would be hospitalized or taken away against the parent's will. No youth-reported access barriers were significantly associated with unmet need. CONCLUSIONS: The economic correlates of unmet need may attain increased importance in the light of current reform in health care financing in the USA. Access may be facilitated by increasing parental knowledge of mental health services and enabling children and adolescents to initiate contact with services independently of their families.

Psychosocial characteristics of physically abused children and adolescents.

OBJECTIVE: To examine the association between physical abuse and selected psychosocial measures in a community-based probability sample of children and adolescents. METHOD: A sample of 9- through 17-year-olds (N = 665) and their caretakers in New York State and Puerto Rico were interviewed in the Methods for the Epidemiology of Child and Adolescent Mental Disorders (MECA) Study. Assessments included the Columbia Impairment Scale, the Instrumental and Social Competence Scale, the Diagnostic Interview Schedule for Children, the Peabody Picture Vocabulary Test, and questions regarding physical abuse. Regression analyses were conducted controlling for family income, family psychiatric history, perinatal problems, physical health, and sexual abuse. RESULTS: A history of physical abuse was reported in 172 (25.9%) of the sample. It was significantly associated with global impairment, poor social competence, major depression, conduct disorder, oppositional defiant disorder, agoraphobia, overanxious disorder, and generalized anxiety disorder but not with suicidality, school grades, or receptive language ability. CONCLUSION: A community probability sample of children and adolescents demonstrated significant associations between physical abuse and psychopathology, after controlling for potential confounders. This supports comprehensive screening for psychopathology among physically abused children and for physical abuse among those with psychopathology. Interventions aimed at improving social competence may be indicated.