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Purpose: Implementation of routine financial screening is a critical step toward mitigating financial toxicity. We evaluated the feasibility, sustainability, and acceptability of systematic financial screening in the outpatient breast oncology clinic at a large, urban cancer center., Methods: We developed and implemented a stakeholder-informed process to systematically screen for financial hardship and worry. A 2-item assessment in English or Spanish was administered to patients through the electronic medical record portal or using paper forms. We evaluated completion rates and mode of completion. Through feedback from patients, clinicians, and staff, we identified strategies to improve completion rates and acceptability., Results: From March, 2021, to February, 2022, 3,500 patients were seen in the breast oncology clinic. Of them, 39% (n = 1,349) responded to the screening items, either by paper or portal, 12% (n = 437) preferred not to answer, and the remaining 49% (n = 1,714) did not have data in their electronic health record, meaning they were not offered screening or did not complete the paper forms. Young adults (18-39 years) were more likely to respond compared with patients 70 years or older (61% v 30%, P < .01). English-preferring patients were more likely to complete the screening compared with those who preferred Spanish (46% v 28%, P < .01). Non-Hispanic White patients were more likely to respond compared with Non-Hispanic Black patients and with Hispanic patients (46% v 39% v 32%, P < .01). Strategies to improve completion rates included partnering with staff to facilitate paper form administration, optimizing patient engagement with the portal, and clearly communicating the purpose of the screening., Conclusion: Systematic financial screening is feasible, and electronic data capture facilitates successful implementation. However, inclusive procedures that address language and technology preferences are needed to optimize screening.

Background: Racial and ethnic minority groups experience a disproportionate burden of SARS-CoV-2 illness and studies suggest that cancer patients are at a particular risk for severe SARS-CoV-2 infection., Aims: The objective of this study was examine the association between neighborhood characteristics and SARS-CoV-2 infection among patients with cancer., Methods and Results: We performed a cross-sectional study of New York City residents receiving treatment for cancer at a tertiary cancer center. Patients were linked by their address to data from the US Census Bureau's American Community Survey and to real estate tax data from New York's Department of City Planning. Models were used to both to estimate odds ratios (ORs) per unit increase and to predict probabilities (and 95% CI) of SARS-CoV2 infection. We identified 2350 New York City residents with cancer receiving treatment. Overall, 214 (9.1%) were infected with SARS-CoV-2. In adjusted models, the percentage of Hispanic/Latino population (aOR = 1.01; 95% CI, 1.005-1.02), unemployment rate (aOR = 1.10; 95% CI, 1.05-1.16), poverty rates (aOR = 1.02; 95% CI, 1.0002-1.03), rate of >1 person per room (aOR = 1.04; 95% CI, 1.01-1.07), average household size (aOR = 1.79; 95% CI, 1.23-2.59) and population density (aOR = 1.86; 95% CI, 1.27-2.72) were associated with SARS-CoV-2 infection., Conclusion: Among cancer patients in New York City receiving anti-cancer therapy, SARS-CoV-2 infection was associated with neighborhood- and building-level markers of larger household membership, household crowding, and low socioeconomic status., Novelty and Impact: We performed a cross-sectional analysis of residents of New York City receiving treatment for cancer in which we linked subjects to census and real estate date. This linkage is a novel way to examine the neighborhood characteristics that influence SARS-COV-2 infection. We found that among patients receiving anti-cancer therapy, SARS-CoV-2 infection was associated with building and neighborhood-level markers of household crowding, larger household membership, and low socioeconomic status. With ongoing surges of SARS-CoV-2 infections, these data may help in the development of interventions to decrease the morbidity and mortality associated with SARS-CoV-2 among cancer patients., (© 2022 The Authors. Cancer Reports published by Wiley Periodicals LLC.)

Introduction: In 2009, the U.S. Preventive Services Task Force updated recommended mammography screening frequency from annual to biennial for average-risk women aged 50-74 years. The association between estimated breast cancer risk and mammography screening frequency was evaluated., Methods: A single-center retrospective cohort study was conducted among racially/ethnically diverse women, aged 50-74 years, who underwent screening mammography from 2014 to 2018. Data on age, race/ethnicity, first-degree family history of breast cancer, previous benign breast biopsies, and mammographic density were extracted from the electronic health record to calculate Breast Cancer Surveillance Consortium 5-year risk of invasive breast cancer, with a 5-year risk ≥1.67% defined as high risk. Multivariable analyses were conducted to determine the association between breast cancer risk factors and mammography screening frequency (annual versus biennial). Data were analyzed from 2020 to 2022., Results: Among 12,929 women with a mean age of 61±6.9 years, 82.7% underwent annual screening mammography, and 30.7% met high-risk criteria for breast cancer. Hispanic women were more likely to screen annually than non-Hispanic Whites (85.0% vs 79.8%, respectively), despite fewer meeting high-risk criteria. In multivariable analyses adjusting for breast cancer risk factors, high- versus low/average-risk women (OR=1.17; 95% CI=1.04, 1.32) and Hispanic versus non-Hispanic White women (OR=1.46; 95% CI=1.29, 1.65) were more likely to undergo annual mammography., Conclusions: A majority of women continue to undergo annual screening mammography despite only a minority meeting high-risk criteria, and Hispanic women were more likely to screen annually despite lower overall breast cancer risk. Future studies should focus on the implementation of risk-stratified breast cancer screening strategies., (Copyright © 2022 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.)

The high-dimensionality, complexity, and irregularity of electronic health records (EHR) data create significant challenges for both simplified and comprehensive health assessments, prohibiting an efficient extraction of actionable insights by clinicians. If we can provide human decision-makers with a simplified set of interpretable composite indices (i.e., combining information about groups of related measures into single representative values), it will facilitate effective clinical decision-making. In this study, we built a structured deep embedding model aimed at reducing the dimensionality of the input variables by grouping related measurements as determined by domain experts (e.g., clinicians). Our results suggest that composite indices representing liver function may consistently be the most important factor in the early detection of pancreatic cancer (PC). We propose our model as a basis for leveraging deep learning toward developing composite indices from EHR for predicting health outcomes, including but not limited to various cancers, with clinically meaningful interpretations., Competing Interests: The authors declare no competing interests., (© 2022 The Author(s).)

The multi-modal and unstructured nature of observational data in Electronic Health Records (EHR) is currently a significant obstacle for the application of machine learning towards risk stratification. In this study, we develop a deep learning framework for incorporating longitudinal clinical data from EHR to infer risk for pancreatic cancer (PC). This framework includes a novel training protocol, which enforces an emphasis on early detection by applying an independent Poisson-random mask on proximal-time measurements for each variable. Data fusion for irregular multivariate time-series features is enabled by a "grouped" neural network (GrpNN) architecture, which uses representation learning to generate a dimensionally reduced vector for each measurement set before making a final prediction. These models were evaluated using EHR data from Columbia University Irving Medical Center-New York Presbyterian Hospital. Our framework demonstrated better performance on early detection (AUROC 0.671, CI 95% 0.667 - 0.675, p < 0.001) at 12 months prior to diagnosis compared to a logistic regression, xgboost, and a feedforward neural network baseline. We demonstrate that our masking strategy results greater improvements at distal times prior to diagnosis, and that our GrpNN model improves generalizability by reducing overfitting relative to the feedforward baseline. The results were consistent across reported race. Our proposed algorithm is potentially generalizable to other diseases including but not limited to cancer where early detection can improve survival., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Autophagy is characterized as a cytoprotective process and inhibition of autophagy with medicinally active agents, such as chloroquine (CQ) is proposed as a prospective adjuvant therapy for cancer. Here, we examined the preclinical effects of CQ combined with the MEK inhibitor trametinib (TRA) on melanoma. We found that cotreatment of CQ and TRA markedly slowed melanoma growth induced in Tyr-CreER . Braf Ca. Pten fl/fl mice. Immunostaining showed that trametinib decreased Ki-67+ proliferating cells, and increased TUNEL+ apoptotic cells. The combo treatment induced a further decrease of Ki-67+ proliferating cells. Consistent with the in vivo findings, CQ and TRA inhibited melanoma cell proliferation in vitro , which was correlated by decreased cyclin D1 expression. In addition, we found that tissues treated with CQ and TRA had significantly decreased numbers of CD4+ and CD8+ T-lymphocytes and F4/80+ macrophages. Together, these results indicate that cotreatment of CQ and TRA decreases cancer cell proliferation, but also dampens immune cell infiltration. Further study is warranted to understand whether CQ-induced immune suppression inadvertently affects therapeutic benefits., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Degan, May, Jin, Hammoda, Sun, Zhang, Wang, Erdmann, Warren and Zhang.)

Background and Aim: Humans with inborn errors of immunity (IEI), or primary immunodeficiencies, may be associated with a potential risk factor for early-onset gastrointestinal (GI) cancer., Methods: We systematically reviewed all cases with clinical diagnoses of both an IEI and a GI cancer in three databases (MEDLINE, SCOPUS, and EMBASE). In total, 76 publications satisfying our inclusion criteria were identified, and data for 149 cases were analyzed. We also searched our institutional cancer registry for such cases., Results: We identified 149 patients with both an IEI and a GI cancer, 95 presented gastric cancer, 13 small bowel cancer, 35 colorectal cancer, and 6 had an unspecified cancer or cancer at another site. Gastric and colon adenocarcinomas were the most common. For both gastric and colorectal cancers, age at onset was significantly earlier in patients with IEIs than in the general population, based on the SEER database. Common variable immunodeficiency (CVID) was the most common IEI associated with gastrointestinal cancer. About 12% of patients had molecular genetic diagnoses, the three most frequently implicated genes being ATM, CARMIL2, and CTLA4. Impaired humoral immunity and Epstein-Barr virus (EBV) infection were frequently reported as factors potentially underlying early-onset GI cancers in patients with IEIs. We identified one patient with CVID and early-onset gastric adenocarcinoma, recurrent diarrhea, and gastrointestinal CMV infection from a retrospective survey., Conclusion: Patients with IEIs should be considered at risk of early-onset GI cancers and should therefore undergo cancer screening at an earlier age., (© 2022 Journal of Gastroenterology and Hepatology Foundation and John Wiley & Sons Australia, Ltd.)

Study Objective: The purpose of this study was to assess the impact of the coronavirus disease 2019 (COVID-19) pandemic on surgical volume and emergency department (ED) consults across obstetrics-gynecology (OB-GYN) services at a New York City hospital., Design: Retrospective cohort study., Setting: Tertiary care academic medical center in New York City., Patients: Women undergoing OB-GYN ED consults or surgeries between February 1, 2020 and April 15, 2020., Interventions: March 16 institutional moratorium on elective surgeries., Measurements and Main Results: The volume and types of surgeries and ED consults were compared before and after the COVID-19 moratorium. During the pandemic, the average weekly volume of ED consults and gynecology (GYN) surgeries decreased, whereas obstetric (OB) surgeries remained stable. The proportions of OB-GYN ED consults, GYN surgeries, and OB surgeries relative to all ED consults, all surgeries, and all labor and delivery patients were 1.87%, 13.8%, 54.6% in the pre-COVID-19 time frame (February 1-March 15) vs 1.53%, 21.3%, 79.7% in the COVID-19 time frame (March 16-April 15), representing no significant difference in proportions of OB-GYN ED consults (p = .464) and GYN surgeries (p = .310) before and during COVID-19, with a proportionate increase in OB surgeries (p <.002). The distribution of GYN surgical case types changed significantly during the pandemic with higher proportions of emergent surgeries for ectopic pregnancies, miscarriages, and concern for cancer (p <.001). Alternatively, the OB surgery distribution of case types remained relatively constant., Conclusion: This study highlights how the pandemic has affected the ways that patients in OB-GYN access and receive care. Institutional policies suspending elective surgeries during the pandemic decreased GYN surgical volume and affected the types of cases performed. This decrease was not appreciated for OB surgical volume, reflecting the nonelective and time-sensitive nature of obstetric care. A decrease in ED consults was noted during the pandemic begging the question "Where have all the emergencies gone?" Although the moratorium on elective procedures was necessary, "elective" GYN surgeries remain medically indicated to address symptoms such as pain and bleeding and to prevent serious medical sequelae such as severe anemia requiring transfusion. As we continue to battle COVID-19, we must not lose sight of those patients whose care has been deferred., (Copyright © 2020 AAGL. Published by Elsevier Inc. All rights reserved.)

Background: Peripheral vascular surgery may be complicated by wound infection and potential graft exposure in the groin area. Muscle flap coverage of the graft has been promoted to address these wound complications. The authors present their findings regarding graft salvage rates and patient outcomes using local muscle flaps to address vascular graft complications of the groin., Methods: Data were obtained by retrospective cohort study of patients who underwent a local muscle flap procedure by a single surgeon following vascular graft complication in the groin., Results: Seventeen patients undergoing local muscle flap coverage of a vascular graft were reviewed. Six men and 9 women, 51-80 years old, were included in the study. Wound complications in the groin occurred anywhere from 3 days to 3.5 years following graft placement. Graft exposure was the most common presenting complication (14 of 17 patients). Muscle flap coverage occurred within 15 days of complication presentation in all patients (average, 6.4 days). Seven of the 15 patients experienced postoperative complications within 6 months of the procedure, most commonly wound dehiscence. However, analysis demonstrated that vascular grafts were successfully salvaged in 10 of the 17 patients (59%) over the course of follow-up (range, 104-1748 days). Average time to muscle flap coverage was 4.2 days in patients who retained the graft and 9.6 days in patients who ultimately lost their vascular graft., Conclusion: The authors demonstrate improved vascular graft salvage rate when local muscle flap procedure is performed early after initial wound complication presentation.

In the genome-engineering era, it is increasingly important that researchers have access to a common set of platform strains that can serve as debugged production chassis and the basis for applying new metabolic engineering strategies for modeling and characterizing flux, engineering complex traits, and optimizing overall performance. Here, we describe such a platform strain of E. coli engineered for ethanol production. Starting with a fully characterized host strain (BW25113), we site-specifically integrated the genes required for homoethanol production under the control of a strong inducible promoter into the genome and deleted the genes encoding four enzymes from competing pathways. This strain is capable of producing >30 g/L of ethanol in minimal media with <2 g/L produced of any fermentative byproduct. Using this platform strain, we tested previously identified ethanol tolerance genes and found that while tolerance was improved under certain conditions, any effect on ethanol production or tolerance was lost when grown under production conditions. Thus, our findings reinforce the need for a metabolic engineering "commons" that could provide a set of platform strains for use in more sophisticated genome-engineering strategies. Towards this end, we have made this production strain available to the scientific community., (Copyright © 2013 Wiley Periodicals, Inc.)

A close correllation between molecular-level interactions and macroscopic characteristics of polymer networks exists. The characteristics of the polymeric hydrogels assembled from β-cyclodextrin (β-CD) and adamantyl (AD) substituted poly(acrylate)s can be tailored through selective host-guest complexation between β-CD and AD substituents and their tethers. Dominantly, steric effects and competitive intra- and intermolecular host-guest complexation are found to control poly(acrylate) isomeric inter-strand linkage in polymer network formation. This understanding of the factors involved in polymeric hydrogel formation points the way towards the construction of increasingly sophisticated biocompatible materials., (Copyright © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

In this article, we describe a simple, sensitive, accurate, and repeatable method for the measurement of phenol and p-cresol (4-methylphenol) in human urine and feces. We examined a number of parameters to identify an optimal extraction protocol. Purification of sample extracts was achieved by low-temperature vacuum microdistillation. Separation was achieved in approximately 15 min by high-performance liquid chromatography (HPLC) with quantification by fluorescence at 284/310 nm. Limits of detection for phenol were 2 ng/ml for urine and 20 ng/g for feces, and those for p-cresol were 10 ng/ml for urine and 100 ng/g for feces. For comparison, approximate mean values for urine are 3 microg/ml for phenol and 30 microg/ml for p-cresol, and those for feces are 1 microg/g for phenol and 50 microg/g for p-cresol. An experienced analyst can process 60 samples each day using this method.

alpha-Cyclodextrin, beta-cyclodextrin, N-(6(A)-deoxy-alpha-cyclodextrin-6(A)-yl)-N'6(A)-deoxy-beta-cyclodextrin-6(A)-yl)urea and N,N-bis(6(A)-deoxy-beta-cyclodextrin-6(A)-yl)urea (alphaCD, betaCD, 1 and 2) form inclusion complexes with E-4-tert-butylphenyl-4'-oxyazobenzene, E-3(-). In aqueous solution at pH 10.0, 298.2 K and I = 0.10 mol dm(-3)(NaClO(4)) spectrophotometric UV-visible studies yield the sequential formation constants: K(11) = (2.83 +/- 0.28) x 10(5) dm(3) mol(-1) for alphaCD.E-(-), K(21) = (6.93 +/- 0.06) x 10(3) dm(3) mol(-1) for (alphaCD)(2).E-3(-), K(11) = (1.24 +/- 0.12) x 10(5) dm(3) mol(-1) for betaCD.E-(-), K(21) = (1.22 +/- 0.06) x 10(4) dm(3) mol(-1) for (betaCD)(2).E-(-), K(11) = (3.08 +/- 0.03) x 10(5) dm(3) mol(-1) for .E-3(-), K(11) = (8.05 +/- 0.63) x 10(4) dm(3) mol(-1) for .E-3(-) and K(12) = (2.42 +/- 0.53) x 10(4) dm(3) mol(-1) for .(E-3(-))(2). (1)H ROESY NMR studies show that complexation of E-3(-) in the annuli of alphaCD, betaCD, 1 and 2 occurs. A variable-temperature (1)H NMR study yields k(298 K)= 6.7 +/- 0.5 and 5.7 +/- 0.5 s(-1), DeltaH = 61.7 +/- 2.7 and 88.1 +/- 4.2 kJ mol(-1) and DeltaS = -22.2 +/- 8.7 and 65 +/- 13 J K(-1) mol(-1) for the interconversion of the dominant includomers (complexes with different orientations of alphaCD) of alphaCD.E-3(-) and (alphaCD)(2).E-3(-), respectively. The existence of E-3(-) as the sole isomer was investigated through an ab initio study.

The preparation of 6(A)-deoxy-6(A)-(6-(2-(1,4,7,10-tetraoxa-13-azacyclopentadecan-13-yl)acetamido)hexylamino)-alpha-cyclodextrin, 3, 6(A)-deoxy-6(A)-(6-(2-(1,4,7,10,13-pentaoxa-16-azacyclooctadecan-16-yl)acetamido)hexylamino)-alpha-cyclodextrin, 4, and their beta-cyclodextrin analogues, 5 and 6, are described. (1)H (600 MHz) ROESY NMR spectra of the C(6) substituted beta-cyclodextrins, 5 and 6, are consistent with the intramolecular complexation of their azacyclopentadecanyl- and azacyclooctadecanyl(acetamido)hexylamino substituents in the beta-cyclodextrin annulus in D(2)O at pD = 8.5 whereas those of their alpha-cyclodextrin analogues, 3 and 4 are not complexed in the alpha-cyclodextrin annulus. This is attributed to the monoazacoronand components of the substituents being able to pass through the beta-cyclodextrin annulus whereas they are too large to pass through the alpha-cyclodextrin annulus. However, the substituents of 3 and 4 are intermolecularly complexed by beta-cyclodextrin to form pseudo [2]-rotaxanes. Metallocyclodextrins are formed by 5 through complexation by the monoazacoronand substituent component for which log (K/dm(3) mol(-1))= <2, 6.34 and 5.38 for Ca(2+), Zn(2+) and La(3+), respectively, in aqueous solution at 298.2 K and I= 0.10 mol dm(-3)(NEt(4)ClO(4)).

(E)-4-tert-Butyl-4'-oxystilbene, 1(-), is thermally stable as the (E)-1(-) isomer but may be photoisomerized to the (Z)-1(-) isomer as shown by UV-vis and (1)H NMR studies in aqueous solution. When (E)-1(-) is complexed by alphaCD two inclusion isomers (includomers) form in which alphaCD assumes either of the two possible orientations about the axis of (E)-1(-) in alphaCD.(E)-1(-) for which (1)H NMR studies yield the parameters: k(1)(298 K)= 12.3 +/- 0.6 s(-1), DeltaH(1)(++)= 94.3 +/- 4.7 kJ mol(-1), DeltaS1(++)= 92.0 +/- 5.0 J K(-1) mol(-1), and k(2)(298 K)= 10.7 +/- 0.5 s(-1), DeltaH(2)(++)= 93.1 +/- 4.7 kJ mol(-1), DeltaS2(++)= 87.3 +/- 5.0 J K(-1) mol(-1) for the minor and major includomers, respectively. The betaCD.(E)-1(-) complex either forms a single includomer or its includomers interchange at the fast exchange limit of the (1)H NMR timescale. Complexation of 1(-) by N-(6(A)-deoxy- alpha-cyclodextrin-6(A)-yl)-N'-(6(A)-deoxy- beta-cyclodextrin-6(A)-yl)urea, results in the binary complexes 2.(E)-1(-) in which both CD component annuli are occupied by (E)-1(-) and which exists exclusively in darkness and 2.(Z)-1(-) in which only one CD component is occupied by (Z)-1(-) and exists exclusively in daylight at lambda > or = 300 nm. Irradiation of solutions of the binary complexes at 300 and 355 nm results in photostationary states dominated by 2.(E)-1(-) and 2.(Z)-1(-), respectively. In the presence of 4-methylbenzoate, 4(-), 2.(Z)-1(-) forms the ternary complex 2.(Z)-1(-).4(-) where 4(-) occupies the second CD annulus. Interconversion occurs between 2.(Z)-1(-).4(-) and 2.(E)-1(-)+4(-) under the same conditions as for the binary complexes alone. Similar interactions occur in the presence of 4-methylphenolate and 4-methylphenylsulfonate. The two isomers of each of these systems represent different states of a molecular device, as do the analogous binary complexes of N,N-bis(6(A)-deoxy- beta-cyclodextrin-6(A)-yl)urea, 3, [3.(E)-1(-) and 3.(Z)-1(-), where the latter also forms a ternary complex with 4(-).

Complexation of the Brilliant Yellow tetraanion, 3(4-), by two new diazacoronand linked beta-cyclodextrin (beta CD) dimers 4,13-bis(2-(6A-deoxy-beta-cyclodextrin-6A-yl)aminooctylamidomethyl- and 4,13-bis(8-(6A-deoxy-beta-cyclodextrin-6A-yl)aminooctylamidomethyl)-4,13- diaza-1,7,10-trioxacyclopentadecane, 1 and 2, respectively, has been studied in aqueous solution. UV-visible spectrophotometric studies at 298.2 K, pH 10.0 and I = 0.10 mol dm-3 (NEt4ClO4) yielded complexation constants for the complexes 1 x 3(4-) and 2 x 3(4-), K1 = (1.08 +/- 0.01) x 10(5) and (6.21 +/- 0.08) x 10(3) dm3 mol-1, respectively. Similar studies at 298.2 K, pH 10.0 and I = 0.10 mol dm-3 (NaClO4) yielded K3 = (4.63 +/- 0.09) x 10(5) and (3.38 +/- 0.05) x 10(4) dm3 mol-1 for the complexation of 3(4-) by Na+ x 1 and Na+ x 2 to give Na+ x 1 x 3(4-) and Na+ x 2 x 3(4-), respectively. Potentiometric studies of the complexation of Na+ by 1 and 2 by the diazacoronand component of the linkers to give Na+ x 1 and Na+ x 2 yielded K2 = (2.00 +/- 0.05) x 10(3) and (1.8 +/- 0.05) x 10(3) dm3 mol-1, respectively, at 298.2 K and I = 0.10 mol dm-3(NEt4ClO4). For complexation of Na+ by 1 x 3(4-) and 2 x 3(4-) to give Na+ x 1 x 3(4-) and Na+ x 2 x 3(4-) K2K3/K1 = K4 = 8.6 x 10(2) and 9.8 x 10(3) dm3 mol-1, respectively. The pKaS of 1H4(4+) are 7.63 +/- 0.01, 6.84 +/- 0.02, 5.51 +/- 0.04 and 4.98 +/- 0.03, and those of 2H4(4+) are 8.67 +/- 0.02, 8.11 +/- 0.02, 6.06 +/- 0.02 and 5.14 +/- 0.05. The larger magnitude of K1 for 1 by comparison with K1 for 2 is attributed to the octamethylene linkers of 2 competing with 3(4-) for occupancy of the annuli of the beta CD entities while the competitive ability of the dimethylene linkers of 1 is less. A similar argument applies to the relative magnitudes of K3 for Na+ x 1 and Na+ x 2. Increased electrostatic attraction probably accounts for K3 > K1 for Na+ x 1 x 3(4-) and 1 x 3(4-) and for Na+ x 2 x 3(4-) and 2 x 3(4-). The lesser magnitudes of K2 and K4 for Na+ x 1 and Na+ x 1 x 3(4-) compared with those for Na+ x 2 and Na+ x 2 x 3(4-) are attributed to the octamethylene linkers of 2 producing a more hydrophobic environment for the diazacoronand than that produced by the dimethylene linkers of 1. 1H NMR spectroscopic studies and the syntheses of 1 and 2 are described.

A pH titration study shows that 6(A)-((2-(bis(2-aminoethyl)amino)ethyl)amino)-6(A)-deoxy-beta-cyclodextrin (betaCDtren) forms binary metallocyclodextrins, [M(betaCDtren)](2+), for which log(K/dm(3) mol(-)(1)) = 11.65 +/- 0.06, 17.29 +/- 0.05, and 12.25 +/- 0.03, respectively, when M(2+) = Ni(2+), Cu(2+), and Zn(2+), where K is the stability constant in aqueous solution at 298.2 K and I = 0.10 mol dm(-)(3) (NaClO(4)). The ternary metallocyclodextrins [M(betaCDtren)Trp](+), where Trp(-) is the tryptophan anion, are characterized by log(K/dm(3) mol(-)(1)) = 8.2 +/- 0.2 and 8.1 +/- 0.2, 9.5 +/- 0.3 and 9.4 +/- 0.2, and 8.1 +/- 0.1 and 8.3 +/- 0.1, respectively, where the first and second values represent the stepwise stability constants for the complexation of (R)- and (S)-Trp(-), respectively, when M(2+) = Ni(2+), Cu(2+), and Zn(2+). From comparisons of stabilities and UV-visible spectra, the binary and ternary metallocyclodextrins appear to be six-coordinate when M(2+) = Ni(2+) and Zn(2+) and five-coordinate when M(2+) = Cu(2+). The factors affecting the stoichiometries and stabilities of the metallocyclodextrins, are discussed and comparisons are made with related systems.

Insulin-like growth factor I (IGF-I), a protein of 70 amino acid residues and 3 cystine bridges, has been synthesized by two solid phase Boc methods. The first method used N-methylpyrrolidinone as the solvent with single coupling cycles while the second synthesis used dimethylformamide and dichloromethane as the solvents with a double-coupling protocol. In both cases, trifluoroacetic acid/trifluoromethanesulphonic acid cleavage of the peptide from the resin was employed. Purification of the cleavage products followed by removal of the S-acetamidomethyl protecting groups gave reduced peptides which were then oxidized under conditions favouring the formation of the correct disulphide bonds. The purified synthetic IGF-I peptides were full agonists of natural IGF-I in a radioimmunoassay, in an IGF-I radioreceptor assay, in a bioassay which measures the stimulation of protein synthesis in rat L6 myoblasts and in an IGF-binding protein competitive binding assay. Moreover, in each of these assays, the synthetic IGF peptides were found to be at least 70% as potent as natural IGF-I.

In order to elucidate the role of the N-terminus of insulin-like growth factor 1 (IGF-1) with respect to its biological properties, we chemically synthesized analogues of IGF-1 truncated by one to five amino acid residues from the N-terminus. In a bioassay that measured the stimulation of protein synthesis in rat L6 myoblasts, the concentrations required to produce a half-maximal response were: IGF-1, 13 ng/ml; des-(1)-IGF-1, 10 ng/ml; des-(1-2)-IGF-1, 13 ng/ml; des-(1-3)-IGF-1, 1.5 ng/ml; des-(1-4)-IGF-1, 5.1 ng/ml; des-(1-5)-IGF-1, 1200 ng/ml. When tested for their abilities to compete with 125I-IGF-1 binding to L6 myoblasts at 3 degrees C, the concentrations required for 50% competition were: IGF-1, des-(1)-IGF-1 and des-(1-2)-IGF-1, 20 ng/ml; des-(1-3)-IGF-1, 14 ng/ml; des-(1-4)-IGF-1, 40 ng/ml; des-(1-5)-IGF-1, greater than 1000 ng/ml. Receptor-binding experiments at 25 degrees C, however, gave results suggesting that the myoblasts were secreting a binding protein selective for the three longest peptides. This interpretation was confirmed by binding studies with medium conditioned by the L6 myoblasts as well as binding protein purified from MDBK-cell-conditioned medium. In both cases IGF-1, des-(1)-IGF-1 and des-(1-2)-IGF-1 competed for tracer IGF-1 binding at least 60-fold better than did the three shorter peptides. The results obtained account for the increased potency of des-(1-3)-IGF-1 and des-(1-4)-IGF-1, since their activities are not attenuated by the binding protein, and the relatively lower potency of des-(1-4)-IGF-1 is a consequence of this peptide binding less well to the L6-myoblast receptor.