Practical and Emotional Peer Support Tailored for Life's Challenges: Personalized Support for Progress Randomized Clinical Pilot Trial in a Veterans Health Administration Women's Clinic

INTRODUCTION

Women Veterans experience a broad range of stressors (e.g., family, relationship, and financial) and high rates of mental health and physical health conditions, all of which contribute to high levels of stress. Personalized Support for Progress (PSP), an evidence-based intervention, is well suited to support women Veterans with high stress as it involves a card-sort task to prioritize concerns as well as pragmatic and emotional support to develop and implement a personalized plan addressing those concerns. Our aims were to explore the population and context for delivery and evaluate the feasibility, acceptability, and utility of PSP delivered by a peer specialist to complement existing services in a Veterans Health Administration (VHA) Women's Wellness Center.

MATERIALS AND METHODS

This randomized controlled pilot trial compared treatment as usual plus PSP to treatment as usual and used the a priori Go/No-Go criteria to establish success for each outcome. We interviewed staff regarding the population and delivery context at a VHA Women's Wellness Center and analyzed interviews using a rapid qualitative approach. For the rapid qualitative analysis, we created templated summaries of each interview to identify key concepts within each a priori theme, reviewed each theme's content across all interviews, and finally reviewed key concepts across themes. We evaluated feasibility using recruitment and retention rates; acceptability via Veteran satisfaction, working relationship with the peer, and staff satisfaction; and utility based on the proportion of Veterans who experienced a large change in outcomes (e.g., stress, mental health symptoms, and quality of life). The Syracuse VA Human Subjects Institutional Review Board approved all procedures.

RESULTS

Staff interviews highlight that women Veterans have numerous unmet social needs and concerns common among women which increase the complexity of their care; call for a supportive, consistent, trusting relationship with someone on their health care team; and require many resources (e.g., staff such as social workers, services such as legal support, and physical items such as diapers) to support their needs (some of which are available within VHA but may need support for staffing or access, and some of which are unavailable). Feasibility outcomes suggest a need to modify PSP and research methods to enhance intervention and assessment retention before the larger trial; the recruitment rate was acceptable by the end of the trial. Veteran acceptability of PSP was high. Veteran outcomes demonstrate promise for utility to improve stress, mental health symptoms, and quality of life for women Veterans.

CONCLUSIONS

Given the high acceptability and promising outcomes for utility, changes to the design to enhance the feasibility outcomes which failed to meet the a priori Go/No-Go criteria are warranted. These outcomes support future trials of PSP within VHA Women's Wellness Centers.

Expanding access to psychosocial research studies during the COVID-19 pandemic through virtual modalities

The COVID-19 pandemic has caused psychosocial researchers and clinicians to quickly shift from standard in-person practices to remote modalities. Despite calls to maintain current virtual care modalities due to the potential to improve access to health care, we are not yet aware of any scholarly works which explicitly describe specific modifications made in response to the restrictions to face-to-face care, resulting access, and implications for the field. This commentary describes how modifications to transition both clinical and research processes to fully virtual modalities in 2 ongoing integrated primary care clinical trials during the COVID-19 pandemic increased access. Given the feasibility of implementing these modifications and the success demonstrated by increased enrollment, we advocate for continued use of virtual modalities for both clinical work and research. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

The ABRF Edman Sequencing Research Group 2008 Study: investigation into homopolymeric amino acid N-terminal sequence tags and their effects on automated Edman degradation

The Edman Sequence Research Group (ESRG) of the Association of Biomolecular Resource designs and executes interlaboratory studies investigating the use of automated Edman degradation for protein and peptide analysis. In 2008, the ESRG enlisted the help of core sequencing facilities to investigate the effects of a repeating amino acid tag at the N-terminus of a protein. Commonly, to facilitate protein purification, an affinity tag containing a polyhistidine sequence is conjugated to the N-terminus of the protein. After expression, polyhistidine-tagged protein is readily purified via chelation with an immobilized metal affinity resin. The addition of the polyhistidine tag presents unique challenges for the determination of protein identity using Edman degradation chemistry. Participating laboratories were asked to sequence one protein engineered in three configurations: with an N-terminal polyhistidine tag; with an N-terminal polyalanine tag; or with no tag. Study participants were asked to return a data file containing the uncorrected amino acid picomole yields for the first 17 cycles. Initial and repetitive yield (R.Y.) information and the amount of lag were evaluated. Information about instrumentation and sample treatment was also collected as part of the study. For this study, the majority of participating laboratories successfully called the amino acid sequence for 17 cycles for all three test proteins. In general, laboratories found it more difficult to call the sequence containing the polyhistidine tag. Lag was observed earlier and more consistently with the polyhistidine-tagged protein than the polyalanine-tagged protein. Histidine yields were significantly less than the alanine yields in the tag portion of each analysis. The polyhistidine and polyalanine protein-R.Y. calculations were found to be equivalent. These calculations showed that the nontagged portion from each protein was equivalent. The terminal histidines from the tagged portion of the protein were demonstrated to be responsible for the high lag during N-terminal sequence analysis.

ABRF ESRG 2006 study: Edman sequencing as a method for polypeptide quantitation

The Edman Sequencing Research Group (ESRG) designs studies on the use of Edman degradation for protein and peptide analysis. These studies provide a means for participating laboratories to compare their analyses against a benchmark of those from other laboratories that provide this valuable service. The main purpose of the 2006 study was to determine how accurate Edman sequencing is for quantitative analysis of polypeptides. Secondarily, participants were asked to identify a modified amino acid residue, N-epsilon-acetyl lysine [Lys(Ac)], present within one of the peptides. The ESRG 2006 peptide mixture consisted of three synthetic peptides. The Peptide Standards Research Group (PSRG) provided two peptides, with the following sequences: KAQYARSVLLEKDAEPDILELATGYR (peptide B), and RQAKVLLYSGR (peptide C). The third peptide, peptide C*, synthesized and characterized by ESRG, was identical to peptide C but with acetyl lysine in position 4. The mixture consisted of 20% peptide B and 40% each of peptide C and its acetylated form, peptide C*. Participating laboratories were provided with two tubes, each containing 100 picomoles of the peptide mixture (as determined by quantitative amino acid analysis) and were asked to provide amino acid assignments, peak areas, retention times at each cycle, as well as initial and repetitive yield estimates for each peptide in the mixture. Details about instruments and parameters used in the analysis were also collected. Participants in the study with access to a mass spectrometer (MALDI-TOF or ESI) were asked to provide information about the relative peak areas of the peptides in the mixture as a comparison with the peptide quantitation results from Edman sequencing. Positive amino acid assignments were 88% correct for peptide C and 93% correct for peptide B. The absolute initial sequencing yields were an average of 67% for peptide (C+C*) and 65.6 % for peptide B. The relative molar ratios determined by Edman sequencing were an average of 4.27 (expected ratio of 4) for peptides (C+C*)/B, and 1.49 for peptide C*/C (expected ratio of 1); the seemingly high 49% error in quantification of Lys(Ac) in peptide C* can be attributed to commercial unavailability of its PTH standard. These values compare very favorably with the values obtained by mass spectrometry.

Construction and biological characterization of an HB-GAM/FGF-1 chimera for vascular tissue engineering

OBJECTIVE

Cardiovascular tissue engineering approaches to vessel wall restoration have focused on the potent but relatively nonspecific and heparin-dependent mesenchymal cell mitogen fibroblast growth factor 1 (FGF-1). We hypothesized that linking FGF-1 to a sequence likely to bind to cell surface receptors relatively more abundant on endothelial cells (ECs) might induce a relative greater EC bioavailability of the FGF-1. We constructed a heparin-binding growth-associated molecule (HB-GAM)/FGF-1 chimera by linking full-length human HB-GAM to the amino-terminus of human FGF-1beta (21-154) and tested its activities on smooth muscle cells (SMCs) and ECs.

METHODS

Primary canine carotid SMCs and jugular vein ECs were plated in 96-well plates in media containing 10% fetal bovine serum and grown to approximately 80% confluence. After being growth arrested in serum-free media for 24 hours, the cells were exposed to concentration ranges of cytokines and heparin, and proliferation was measured with tritiated-thymidine incorporation. Twenty percent fetal bovine serum was used as positive control, and phosphate-buffered saline was used as negative control.

RESULTS

In the presence of heparin the HB-GAM/FGF-1 chimera stimulated less SMC proliferation than did the wild-type FGF-1 with a median effective dose of approximately 0.3 nmol versus approximately 0.1 nmol (P <.001). By contrast, the chimera retained full stimulating activity on EC proliferation with a median effective dose of 0.06 nmol for both cytokines. Unlike the wild-type protein, the chimera possessed heparin-independent activity. In the absence of heparin, the chimera induced dose-dependent EC and SMC proliferation at 0.06 nmol or more compared with the wild-type FGF-1, which stimulated minimal DNA synthesis at 6.0-nmol concentrations.

CONCLUSIONS

The HB-GAM/FGF-1 chimera displays significantly greater and uniquely heparin-independent mitogenic activity for both cell types, and in the presence of heparin it displays a significantly greater EC specificity.

Reporting the outcomes of care: effecting the transition from caring to comparing

Accountability in health care has taken on new dimensions with the drive to base contracting and provider of care selection upon data driven "report cards." The measurement and development of reportable outcomes are driving providers to move their organizations from a focus not only on "caring" but to one highly cognizant of "comparing" in order to maintain market position and meet regulatory requirements. This article defines the areas of organizational transition required for reporting, and profiles the actions taken by three health care providers moving to an organizational style ready for "comparative" competition.

The cysteine-free fibroblast growth factor 1 mutant induces heparin-independent proliferation of endothelial cells and smooth muscle cells

BACKGROUND

The structure/function relationships of fibroblast growth factor 1 (FGF-1) are being investigated using site mutation, yielding novel structures with potential clinical applicability for modulating tissue responses to vascular interventions. We generated a mutant FGF-1 in which all three cysteines were converted to serines and then tested the relative mitogenic activities on endothelial cells (ECs) and smooth muscle cells (SMCs) and the molecular stability of the protein to thrombin-induced degradation.

METHODS

The dose responses of wild-type FGF-1 and the Cys-free mutant in the absence or presence of heparin were tested on ECs and SMCs. Cell proliferation was measured by [(3)H]thymidine incorporation. Data were normalized by positive control (20% fetal bovine serum) and expressed as percentage of positive control for comparison. The molecular stability was examined by exposure of the cytokines to thrombin at 37 degrees C for 0.5-24 h and then analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis.

RESULTS

Unlike wild-type FGF-1 which induced only minimal DNA synthesis at concentrations as high as 100 ng/ml, the Cys-free mutant induced a dose-dependent proliferation starting at 1 ng/ml on both ECs and SMCs in the absence of heparin. At 100 ng/ml, Cys-free mutant induced 4-fold more proliferation than wild-type FGF-1 on ECs (76.64 +/- 13.39% vs 14.58 +/- 1.38%, P < 0.01) and 12-fold more proliferation on SMCs (143.52 +/- 9.96 vs 11.25 +/- 3.32, P < 0.01). Heparin 5 U/ml potentiated the mitogenic activity of the Cys-free mutant at low dose range. Both proteins were degraded by thrombin progressively. But the Cys-free mutant showed more susceptibility with accelerated appearance of lower-molecular-weight fragment bands after incubation with thrombin.

CONCLUSIONS

Conversion of cysteine residues to serine changed the heparin dependency of the growth factor and increased its mitogenic activity and its susceptibility to thrombin-induced degradation.

Modulation of vascular cell growth kinetics by local cytokine delivery from fibrin glue suspensions

PURPOSE

Fibrin glue (FG) has been used as a delivery system for bioactive agents on grafts and angioplasty sites. Reports from two different institutions suggest that heparin concentrations of 500 U/mL in FG inhibit smooth muscle cell (SMC) proliferation, but do not effect endothelial cell (EC) proliferation. The purposes of this study were to (1) quantify the diffusive release of fibroblast growth factor-1 (FGF-1) and heparin from FG; (2) determine the effect of heparin and FGF-1 on SMC proliferation when the cells are immediately plated on the FG; and (3) by means of the diffusive release data, design a new in vitro model that may differentiate the effect of FG-incorporated FGF-1 and heparin, rather than the released, solubilized components of these two factors, on SMC and EC proliferation.

METHODS

125I-FGF-1 or 3H-heparin release from FG into the overlying media was measured serially in a 96-hour period, either with or without cells. SMCs were immediately plated on FG containing various concentrations of FGF-1 and heparin. SMCs or ECs were plated on identical groups of FG containing FGF-1 and heparin 24 hours after the FG was made to exclude the effect on cell growth of the initial release of FGF-1 into the media.

RESULTS

In the first 24 hours, 70% +/- 1% of the FGF-1 and 59% +/- 2% of the heparin in the FG was released into the overlying media, with minimal release occurring thereafter. The cell type or absence of cells did not affect release, but there was five times more FGF-1 and four times more heparin in the media at 72 hours for the immediate plating versus the delayed plating because of a diffusive release primarily in the first 24 hours. A heparin concentration of 500 U/mL inhibited SMC proliferation, as compared with 5 U/mL heparin, only when immediate plating of SMCs was used. Comparing immediate versus delayed SMC plating, at equivalent FGF-1 and heparin doses, immediate plating induced greater proliferation than delayed plating; this was likely caused by the higher soluble FGF-1 concentration. Heparin doses as high as 500 U/mL had little effect on SMC proliferation. In contrast, ECs died with delayed plating on FG containing 500 U/mL heparin, and their growth was inhibited at 50 U/mL heparin, as compared with 5 U/mL heparin.

CONCLUSION

The differences in SMC proliferation when comparing immediate versus delayed plating are likely caused by diffusive release of heparin and FGF-1 into the media. Our ongoing work uses an optimized in vitro FG system that minimizes the effects of soluble factors. This is an important distinction, because the cytokines that are released in vivo will be removed by blood flow and, thus, may not exert an effect unless they are contained within the FG.

S100A13 is involved in the regulation of fibroblast growth factor-1 and p40 synaptotagmin-1 release in vitro

We have previously characterized the release of the signal peptide sequence-less fibroblast growth factor (FGF) prototype, FGF-1, in vitro as a stress-induced pathway in which FGF-1 is released as a latent homodimer with the p40 extravesicular domain of p65 synaptotagmin (Syn)-1. To determine the biologic relevance of the FGF-1 release pathway in vivo, we sought to resolve and characterize from ovine brain a purified fraction that contained both FGF-1 and p40 Syn-1 and report that the brain-derived FGF-1:p40 Syn-1 aggregate is associated with the calcium-binding protein, S100A13. Since S100A13 binds the anti-inflammatory compound amlexanox and FGF-1 is involved in inflammation, we examined the effects of amlexanox on the release of FGF-1 and p40 Syn-1 in response to stress in vitro. We report that while amlexanox was able to repress the heat shock-induced release of FGF-1 and p40 Syn-1 in a concentration-dependent manner, it had no effect on the constitutive release of p40 Syn-1 from p40 Syn-1 NIH 3T3 cell transfectants. These data suggest the following: (i) FGF-1 is associated with Syn-1 and S100A13 in vivo; (ii) S100A13 may be involved in the regulation of FGF-1 and p40 Syn-1 release in response to temperature stress in vitro; and (iii) the FGF-1 release pathway may be accessible to pharmacologic regulation.

Analysis of putative heparin-binding domains of fibroblast growth factor-1. Using site-directed mutagenesis and peptide analogues

The contribution of individual basic amino acids within three putative "consensus sequences" for heparin binding of fibroblast growth factor-1 have been examined by site-directed mutagenesis. The results indicate that a significant reduction in the apparent affinity of fibroblast growth factor-1 for heparin is only observed when basic residues in one of the three regions are mutated. Mutation in the other regions are without affect on heparin binding. The heparin binding properties of synthetic peptides based on the three "consensus sequences" paralleled the mutagenesis results. That is, synthetic peptides corresponding to regions of the protein that were affected by mutagenesis with respect to heparin binding exhibited a relatively high affinity for immobilized heparin, whereas those corresponding to regions of similar charge density that were unaffected by mutagenesis did not. In addition, amino acid substitution of a nonbasic residue in the heparin-binding peptide could abolish its heparin binding capacity. The heparin-binding peptide could antagonize the mitogenic activity of FGF-1, probably because of the heparin dependence of this activity. Together these data demonstrate that the heparin binding properties of fibroblast growth factor-1 are dictated by structural features more complex than clusters of basic amino acids. The results of these and other studies indicate that consensus motifs for heparin-binding require further definition. More importantly, the results provide a basis for the design of peptide-based inhibitors of FGF-1.

Murine cortactin is phosphorylated in response to fibroblast growth factor-1 on tyrosine residues late in the G1 phase of the BALB/c 3T3 cell cycle

We have previously reported that BALB/c 3T3 cells require a prolonged exposure to fibroblast growth factor (FGF)-1 for the stimulation of maximal DNA synthesis, and this event correlates with the tyrosine phosphorylation of novel proteins late in G1 including a protein termed p80/p85 (Zhan, X., Hu, X., Friesel, R., and Maciag, T. (1993) J. Biol. Chem. 268, 9611-9620). We have purified, sequenced, and cloned the cDNA encoding p80/p85 and report that it is the murine homolog of the chicken cortactin gene and a member of the human hematopoietic specific-1 gene family. Immunochemical analysis of m-cortactin-tyrosine phosphorylation in response to FGF-1 demonstrates a biphasic phosphorylation pattern both as a weak immediate-early and strong mid to late G1 response protein. Because the chicken cortactin gene was originally isolated as a substrate for v-Src, FGF-1 may influence the enzymatic activity of other cell-associated tyrosine kinases which utilize p80/p85 (cortactin) as a polypeptide substrate.

The identification of O-glycosylated precursors of insulin-like growth factor II

A procedure that combined ion exchange, gel permeation, and insulin-like growth factor-binding protein 3 (IGF-BP-3) affinity chromatography with chromatofocusing and reversed-phase high pressure liquid chromatography was used to isolate high molecular weight precursors of human insulin-like growth factor II (IGF-II) from acetic acid extracts of Cohn fraction IV1. Two precursors had isoelectric points (pI) of 5.1 and 5.4 and apparent Mr values of 15,000 and 11,500, respectively. An apparent Mr = 16,000 RLPG/Ser29 variant of IGF-II was also identified in the acetic acid extracts. Amino-terminal amino acid sequencing of the major E domain-containing peptide that had been isolated from apparent Mr = 15,000 IGF-II (pI 5.1), following its digestion with the endoprotease Lys-C, indicated the carboxyl terminus of this precursor was near or at Lys88. During the sequencing of this peptide, a sharply reduced yield of derivatized amino acid occurred at cycle 10, indicating that Thr75 had been posttranslationally modified, possibly by O-glycosylation. To evaluate this possibility, the 125I-labeled high molecular weight IGF-IIs and their endoprotease-generated peptides were treated with glycosidases, and their effects were determined from the change in relative mobilities of the polypeptide and peptides during sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Neuraminidase treatment of apparent Mr = 15,000 and 11,500 IGF-II reduced their Mr values to a common value of 10,500. When the desialylated precursors of IGF-II were treated with O-glycosidase, but not when treated with N-glycosidase, the Mr values were reduced further to about 10,000. This was the Mr value that would be predicted for an unglycosylated form of precursor IGF-II that had a carboxyl-terminal end at or near Lys88. When the Ser66-Lys88 endoprotease-generated E domain peptides from pI5.1 and 5.4 high Mr IGF-II were treated with the glycosidases, they had relative mobility changes during sodium dodecyl sulfate-polyacrylamide gel electrophoresis that were similar to those of the intact precursors. Finally, the association of O-linked oligosaccharide with the E domain peptide of IGF-II was confirmed by demonstrating the specificity of binding of the Ser66-Lys88 asialoglycopeptide to jackfruit lectin.

Binding specificities and transducing function of the different molecular weight forms of insulin-like growth factor-II (IGF-II) on IGF-I receptors

In a study that was reported from this laboratory, the mitogenic potency of an apparent mol wt (appMr) of 15,000 precursor form of human insulin-like growth factor-II (hIGF-II) was shown to be greater than that of completely processed hIGF-II for human fetal-derived fibroblasts, and both were more potent than rIGF-I. Since it is generally acknowledged that the stimulation of cell replication by the IGFs is mediated by IGF-I receptors, we undertook to determine whether differences between the receptors' affinity for the two Mr forms of hIGF-II and recombinant IGF-I (rIGF-I) or between its efficiency to couple specific growth factor occupancy to the activation of protein kinase could explain the greater replicating potential of appMr 15,000 hIGF-II. Equilibrium dissociation, i.e. Kd, and inhibition, i.e. Ki, constants were determined by measuring the ability of rIGF-I, hIGF-II, appMr 15,000 hIGF-II, insulin, and the antireceptor monoclonal antibody alpha IR-3 to compete with 125I-labeled rIGF-I and hIGF-II for binding to purified preparations of IGF-I receptors prepared from an enriched source of fetal membrane, i.e. human term placenta. The results of these experiments established that 1) hIGF-II and appMr 15,000 hIGF-II bind to the IGF-I receptor with the same affinity as rIGF-I, e.g. with Kd and Ki values between 0.03-0.07 nM; 2) the total binding capacity, i.e. Ro, for IGF-I binding was not statistically different from the Ro calculated for IGF-II binding; and 3) the statistical analysis of 12 data sets from the competitive binding experiments for goodness of fit indicated that a 1-site model for IGF-I and -II binding was a better fit of the data than a 2-site model. Measurements of the stimulation of IGF-I receptor autophosphorylation at low ligand concentrations established that appMr 15,000 hIGF-II and hIGF-II were more effective than rIGF-I in coupling receptor occupancy to the activation of its protein kinase. At saturating ligand concentrations, the 3 had similar potencies. The original preparation of appMr 15,000 hIGF-II contains a mixture of forms with acidic isoelectric points (pIs) and was more potent than Mr 7,500 IGF-II in stimulating receptor autophosphorylation. These results are consistent with the relative potencies of this preparation, hIGF-II, and rIGF-I in stimulating the replication of 12-week-old fetal dermal fibroblasts.(ABSTRACT TRUNCATED AT 400 WORDS)

Structure-function studies of heparin-binding (acidic fibroblast) growth factor-1 using site-directed mutagenesis

The heparin-binding or fibroblast growth factors (HBGFs) modulate cell growth and migration, angiogenesis, wound repair, neurite extension, and mesoderm induction. Relatively little is known regarding the precise mechanism of action of these growth factors or the structural basis for their action. A better understanding of the structural basis for the different activities of these proteins should lead to the development of agonists and antagonists of specific HBGF activities. In this report, we summarize evidence that indicates that the heparin-binding and mitogenic activities of HBGF-1 can be dissociated from the receptor-binding activities of the growth factor by site-directed mutagenesis of a single lysine residue. Thus, the mutant HBGF-1 has normal receptor-binding activity and is capable of stimulating tyrosine kinase activity and proto-oncogene expression but is not able to elicit a mitogenic response. A similar dissociation of early events such as proto-oncogene expression from the mitogenic response is observed when the human wild-tupe HBGF-1 is used in the absence of added heparin. These results indicate that intracellular sites of action by the growth factor may be required to complete the mitogenic response. Further evidence for this idea is provided by transfection experiments where NIH 3T3 cells are engineered to produce large quantities of wild-type or mutant HBGF-1. Production of wild-type induces a transformed phenotype, whereas over-production of the mutant does not. The majority of both forms of the protein is found in the nuclear fraction of the transfected cells. Additional site-directed mutagenesis of putative nuclear translocation sequences in the wild-type protein do not affect mitogenic activity.(ABSTRACT TRUNCATED AT 250 WORDS)

Insulin-like growth factor receptor expression and function in human breast cancer

The insulin-like growth factors IGF-I and IGF-II are potent mitogens for several breast tumor cell lines in culture. Additionally, both IGF-I and IGF-II mRNAs are easily detected in the majority of breast tumor specimens examined, while no breast cancer epithelial cell lines we have studied express authentic IGF-I mRNA, and few lines express IGF-II mRNA. Although receptors for insulin, IGF-I, and IGF-II have been described, there is significant cross-reactivity between the various receptors and ligands in the insulin/insulin-like growth factor family, and it is not clear which receptor or receptors are responsible for the biological effects of these growth factors in this system. Using an RNase protection assay, we examined breast tumor specimens and breast cancer epithelial cell lines for expression of mRNA encoding the type I and type II IGF receptors as well as the insulin receptor. Virtually all of the specimens examined expressed mRNA for all three receptors. We then examined estrogen-dependent MCF-7 cells for the mitogenic effects of IGF-I and II in the presence of antibodies to both the type I and type II receptors. alpha IR-3, a monoclonal antibody which blocks the type I receptor, abolished the mitogenic effects of both IGF-I and IGF-II. It did not, however, block the mitogenic effects of insulin. We conclude that type I and type II IGF receptors are ubiquitously expressed in breast cancer, and our experiments with MCF-7 cells suggest the mitogenic effects of both IGF-I and IGF-II are mediated via the type I IGF receptor.

Purification and characterization of an insulin-like growth factor II variant from human plasma

An insulin-like growth factor II variant (IGF-II variant) was purified from Cohn fraction IV1 of human plasma by ion exchange, gel filtration, and reversed-phase high pressure liquid chromatography. The amino-terminal sequence of the first 35 amino acid residues showed a replacement of Ser-29 of IGF-II with the tetrapeptide Arg-Leu-Pro-Gly of IGF-II variant. Peptides isolated and sequenced after digestion with endoproteinase Asp-N and endoproteinase Glu-C disclosed no differences with the sequence predicted from an IGF-II variant cDNA clone isolated by Jansen, M., van Shaik, F. M. A., van Tol, H., Van den Brande, J. L., and Sussenbach, J. S. (1985) FEBS Lett., 179, 243-246. The molecular ion of intact IGF-II variant was 7809.4 mass units, as measured by plasma desorption mass spectrometry. This is in close agreement with the molecular ion of 7812.8 mass units calculated from the determined sequence and indicates the entire amino acid sequence had been accounted for. Binding of IGF-II variant to purified insulin-like growth factor I (IGF-I) receptors demonstrated a 2-3-fold lower affinity for this receptor compared with IGF-I or IGF-II. The dissociation constants for IGF-I, IGF-II, and IGF-II variant are 0.23, 0.38, and 0.80 nM, respectively. In a growth assay, the concentration of IGF-II and IGF-II variant required to stimulate the half-maximal growth of MCF-7 cells was 4 and 13 nM, respectively. Finally, the amount of IGF-II variant that can be purified by this method constitutes approximately 25% of the total IGF-II isolated from Cohn fraction IV1 of human plasma.

International Collaborative Effort (ICE) on birthweight; plurality; and perinatal and infant mortality. I: Methods of data collection and analysis

This paper describes the collection and analysis of data by a group of international collaborators (International Collaborative Effort on Perinatal and Infant Mortality) interested in comparative studies on birthweight distributions and reproductive outcome. This is the first of a series of reports on the results of these studies. It gives an account of the countries or states involved, and the collection and characteristics of the data. The countries and states included sixteen of the United States, plus England and Wales, Denmark, Bavaria and North Rhine-Westphalia from the Federal Republic of Germany, Israel, Japan, Norway, Scotland, and Sweden. The data comprised birthweight distributions in 500-gram groups for all births and for singletons separately, for livebirths, stillbirths, first week deaths and, where available, late neonatal and infant deaths, from 1970 up to 1985.

International Collaborative Effort (ICE) on birthweight; plurality; and perinatal and infant mortality. II: Comparisons between birthweight distributions of births in member countries from 1970 to 1984

Member states of the International and Collaborative Effort (ICE) are the United States of America, England and Wales, Denmark, Bavaria and North Rhine-Westphalia of the Federal Republic of Germany, Israel, Japan, Norway, Scotland and Sweden. The group has collected, analysed and compared distributions of birthweight for member countries, where available from 1970 onwards, for singleton and all livebirths, stillbirths, early and late neonatal and postneonatal deaths. The present paper is an account of the differences in birthweight distributions, and trends over time seen between and within countries, for livebirths and stillbirths. The major findings are the relative robustness over time of the parameters which characterize the distribution of birthweight within countries, and the marked and consistent differences between these distributions in different countries.

Isolation of a biologically active fragment from the carboxy terminus of the fetal rat binding protein for insulin-like growth factors

We have purified a 14 kDa fragment of the 30 kDa binding protein for insulin-like growth factors (IGFs) from BRL-3A cell conditioned medium. The fragment binds IGF-I and IGF-II with similar specificity to the 30 kDa binding protein, but with lower affinity. It corresponds to the carboxy terminus of the native binding protein (residues 148-270), and is thought to arise by proteolysis. We infer that this region of the native binding protein contains, at least in part, the IGF binding domain.

Insulin-like growth factor II mRNA expression in human breast cancer

Insulin-like growth factor II is a growth factor important in fetal development. Several cancer tissues and cell lines have been reported to express IGF-II and rat IGF-II is mitogenic for breast cancer cell lines. Using Northern analysis and ribonuclease protection assays, IGF-II mRNA was detected in normal fibroblasts and in the established breast cancer cell line, T47D. In this cell line, steady state levels of IGF-II message were increased by treatment with estradiol. 10 nM IGF-II, purified from human serum, was mitogenic for breast cancer cell lines. In vitro, IGF-II may act as an autocrine growth factor for some cell lines. RNA derived from breast cancer, pathologically normal breast tissue, and benign breast disease also contained IGF-II mRNA. When paired samples of normal and cancer tissue were obtained from the breast of the same patient, the level of IGF-II mRNA expression in the normal tissue was at least that found in the cancer. This is consistent with previous observations that show IGF-II is expressed in mesenchyme. These findings suggest that in breast cancer IGF-II is produced by stromal tissue elements and potentially by the malignant epithelial cells. Therefore, IGF-II may function as an autocrine or a paracrine growth factor in different breast tumors.

Purification and characterization of a unique high molecular weight form of insulin-like growth factor II

A form of insulin-like growth factor II (IGF-II) with a mol wt of 15,000 has been purified to homogeneity from human Cohn fraction IV1-4. This protein has an amino-terminal sequence through the first 28 residues that is identical to 7.5K IGF-II. The amino acid composition of 15K IGF-II, however, indicates that its carboxyl-terminal region may be different from that predicted from the analysis of IGF-II cDNA clones. The affinities of 15K IGF-II for receptors on rat placental membranes and for an IGF-binding protein that was isolated from the medium of cultured buffalo rat liver cells were similar to those of the 7.5K form of the growth factor. A best-fit analysis of data from the binding of the two mol wt forms of IGF-II to receptors on rat placental membranes by the LIGAND program was consistent with a model in which 7.5K and 15K IGF-II bound to one site with Kd values of 0.27 +/- 0.03 and 0.38 +/- 0.04, respectively. There was an indication that 15K IGF-II also bound to a second low affinity site on the membrane. In mitogenesis assays performed on human fibroblasts isolated from the skin of two fetuses of an early gestational age, 15K IGF-II stimulated the incorporation of [3H]thymidine into DNA at a half-maximal concentration, i.e. ED50, of 5.7 and 5.0 nM. In these experiments, the ED50 values for 7.5K IGF-II were 8.7 and 15 nM.

Impaired central error-correcting behavior in schizophrenia

Previous work has suggested that normal subjects are able to recognize and correct their own errors of movement without using exteroceptive signals. This ability may be impaired in schizophrenia. Twelve normal subjects, 12 alcoholics, and 14 schizophrenics performed a step-function tracking task designed to prevent the use of exteroceptive signals in correcting errors of movement. The mean probability of correcting an error without external cues was approximately .38 in schizophrenics, .70 in normal subjects, and .75 in hospitalized alcoholic patients. There was no difference between groups in the ability to initiate correct responses. The results suggest that schizophrenics are deficient in the ability to monitor ongoing motor behavior on the basis of internal, self-generated cues.