Wastewater surveillance provides 10-days forecasting of COVID-19 hospitalizations superior to cases and test positivity: A prediction study

Background

The public health response to COVID-19 has shifted to reducing deaths and hospitalizations to prevent overwhelming health systems. The amount of SARS-CoV-2 RNA fragments in wastewater are known to correlate with clinical data including cases and hospital admissions for COVID-19. We developed and tested a predictive model for incident COVID-19 hospital admissions in New York State using wastewater data.

Methods

Using county-level COVID-19 hospital admissions and wastewater surveillance covering 13.8 million people across 56 counties, we fit a generalized linear mixed model predicting new hospital admissions from wastewater concentrations of SARS-CoV-2 RNA from April 29, 2020 to June 30, 2022. We included covariates such as COVID-19 vaccine coverage in the county, comorbidities, demographic variables, and holiday gatherings.

Findings

Wastewater concentrations of SARS-CoV-2 RNA correlated with new hospital admissions per 100,000 up to ten days prior to admission. Models that included wastewater had higher predictive power than models that included clinical cases only, increasing the accuracy of the model by 15%. Predicted hospital admissions correlated highly with observed admissions (r = 0.77) with an average difference of 0.013 hospitalizations per 100,000 (95% CI = [0.002, 0.025]).

Interpretation

Using wastewater to predict future hospital admissions from COVID-19 is accurate and effective with superior results to using case data alone. The lead time of ten days could alert the public to take precautions and improve resource allocation for seasonal surges.

Perfluoroalkyl substances (PFAS) and lead (Pb) as "cardiovascular disruptors" in 9-11-year-old children living in Syracuse, New York, United States

OBJECTIVE

Per- and polyfluoro-alkyl substances (PFAS) and lead (Pb) are ubiquitous environmental toxicants with apparent impact on cardiovascular disease (CVD) risk. As one possible mechanism for this increased risk, we have previously demonstrated an association between Pb exposure and heightened cardiovascular reactivity to acute psychological stress, a CVD risk factor. The present study expands this approach and considers both PFAS and Pb exposures (and the possible interaction).

METHODS

We assessed 14 serum PFAS and whole blood Pb concentrations in a sample of 9-11 year-old children (N = 291; 43.2% White, 56.8% Black; 53.5% female). We measured cardiovascular functioning at rest and during psychological stress as well as multiple indicators of subclinical CVD including resting blood pressure (BP), carotid-femoral pulse wave velocity (cfPWV), carotid intima-media thickness (cIMT), and left ventricular mass (LVM). Data analysis included general linear modeling as well as a non-parametric approach to study metal mixtures, specifically Bayesian Kernel Machine Regression (BKMR).

RESULTS

Significant interactions between different PFAS and with Pb suggest the importance of considering toxicant mixtures when assessing potential disruption of the cardiovascular system. The pattern of findings suggests that greater "vascular reactivity" (elevated BP and vascular resistance during acute psychological stress) was associated with higher concentrations of perfluorononanoic acid (PFNA), perfluorohexane sulfonate (PFHxS), and Pb, but only when perfluorooctanoic acid (PFOA) was concurrently elevated. With respect to subclinical outcomes, increasing perfluorodecanoic acid (PFDA) was associated with greater cIMT (β = 0.21, p = 0.010).

CONCLUSION

To our knowledge this is the first study to consider how PFAS exposures might affect cardiovascular functioning and subclinical disease. Although a complex pattern of associations emerged, it does appear that PFAS and Pb can be classified as "cardiovascular disruptors" in children. Further research is needed to replicate these novel findings and determine whether these disruptions produce future cardiovascular disease.

Establishing a Statewide Wastewater Surveillance System in Response to the COVID-19 Pandemic: A Reliable Model for Continuous and Emerging Public Health Threats

CONTEXT

The COVID-19 pandemic sparked efforts across the globe to implement wastewater surveillance for SARS-CoV-2.

PROGRAM

New York State (NYS) established the NYS Wastewater Surveillance Network to estimate the levels of COVID-19 community risk and to provide an early indication of SARS-CoV-2 transmission trends. The network is designed to provide a better understanding of public health burdens and to assist health departments to respond effectively to public health threats.

IMPLEMENTATION

Wastewater surveillance across NYS increased from sporadic and geographically spare in 2020 to routine and widespread in 2022, reaching all 62 counties in the state and covering 74% of New Yorkers. The network team focused on engaging local health departments and wastewater treatment plants to provide wastewater samples, which are then analyzed through a network-affiliated laboratory. Both participating local health departments and wastewater treatment plants receive weekly memos on current SARS-CoV-2 trends and levels. The data are also made publicly available at the state dashboard.

EVALUATION

Using standard indicators to evaluate infectious disease surveillance systems, the NYS Wastewater Surveillance Network was assessed for accuracy, timeliness, and completeness during the first year of operations. We observed 96.5% sensitivity of wastewater to identify substantial/high COVID-19 transmission and 99% specificity to identify low COVID-19 transmission. In total, 80% of results were reported within 1 day of sample collection and were published on the public dashboard within 2 days of sample collection. Among participating wastewater treatment plants, 32.5% provided weekly samples with zero missing data, 31% missed 1 or 2 weeks, and 36.5% missed 3 or more weeks.

DISCUSSION

The NYS Wastewater Surveillance Network continues to be a key component of the state and local health departments' pandemic response. The network fosters prompt public health actions through real-time data, enhancing the preparedness capability for both existing and emerging public health threats.

Exposure to Arsenic and Subclinical Cardiovascular Disease in 9- to 11-Year-Old Children, Syracuse, New York

Importance

Studies in adults have demonstrated associations between arsenic exposure and clinical and subclinical cardiovascular disease (CVD). No studies to date have considered potential associations in children.

Objective

To examine the association between total urinary arsenic levels in children and subclinical indicators of CVD.

Design, Setting, and Participants

This cross-sectional study considered 245 children, a subset from the Environmental Exposures and Child Health Outcomes (EECHO) cohort. Children from the Syracuse, New York, metropolitan area were recruited from August 1, 2013, until November 30, 2017, with enrollment throughout the year. Statistical analysis was performed from January 1, 2022, to February 28, 2023.

Exposures

Total urinary arsenic was measured using inductively coupled plasma mass spectrometry. Creatinine concentration was used to adjust for urinary dilution. In addition, potential exposure routes (eg, diet) were measured.

Main Outcomes and Measures

Three indicators of subclinical CVD were assessed: carotid-femoral pulse wave velocity, carotid intima media thickness, and echocardiographic measures of cardiac remodeling.

Results

The study sample included 245 children aged 9 to 11 years (mean [SD] age, 10.52 [0.93] years; 133 [54.3%] female). The geometric mean of the creatinine-adjusted total arsenic level in the population was 7.76 μg/g creatinine. After adjustment for covariates, elevated total arsenic levels were associated with significantly greater carotid intima media thickness (β = 0.21; 95% CI, 0.08-0.33; P = .001). In addition, echocardiography revealed that elevated total arsenic was significantly higher for children with concentric hypertrophy (indicated by greater left ventricular mass and greater relative wall thickness; geometric mean, 16.77 μg/g creatinine; 95% CI, 9.87-28.79 μg/g) relative to the reference group (geometric mean, 7.39 μg/g creatinine; 95% CI, 6.36-8.58 μg/g). With respect to exposure source, significant geographic clustering of total arsenic was found in 1 urban area of Syracuse, New York.

Conclusions and Relevance

These findings suggest a significant association between arsenic exposure and subclinical CVD in children. Elevated total arsenic levels were found in an area of Syracuse with known elevations of toxic metals from industrial waste, suggesting historical pollution as a possible source. Given the novelty and potential importance of this association, further research is needed to confirm our findings. Any potential effect of urinary arsenic exposure in childhood on actual clinical CVD outcomes in adulthood remains to be determined.

Airborne levels of cadmium are correlated with urinary cadmium concentrations among young children living in the New York state city of Syracuse, USA

Air pollution is a serious public health issue with early childhood exposure being of high concern because of the greater risk that children might experience negative health outcomes. Industrial sources in and near communities are one potential path of exposure that children might face with greater levels of air pollution correlating with higher levels of toxicants detected in children. We compare estimated ambient air concentrations of Cadmium (Cd) to a cohort (n = 281) of 9 to 11-year old children during their early childhood years (0-5 years of age) in a mid-size city in Upstate New York. Levels of Cd air pollution are compared to children's urine-Cd levels. Urine has been shown to be a superior biomarker to blood for Cd exposure particularly for longer-term exposures. We find that participants who reside in households that faced greater Cd air pollution during the child's early years have higher urine-Cd levels. This association is stable and stronger than previously presented associations for blood-Cd. Findings support expanded use of air modelling data for risk screening to reduce the potential health burden that industrial pollution can have.

Using geographic information systems to link population estimates to wastewater surveillance data in New York State, USA

Sewer systems provide many services to communities that have access to them beyond removal of waste and wastewater. Understanding of these systems' geographic coverage is essential for wastewater-based epidemiology (WBE), which requires accurate estimates for the population contributing wastewater. Reliable estimates for the boundaries of a sewer service area or sewershed can be used to link upstream populations to wastewater samples taken at treatment plants or other locations within a sewer system. These geographic data are usually managed by public utilities, municipal offices, and some government agencies, however, there are no centralized databases for geographic information on sewer systems in New York State. We created a database for all municipal sewersheds in New York State for the purpose of supporting statewide wastewater surveillance efforts to support public health. We used a combination of public tax records with sewer access information, physical maps, and municipal records to organize and draw digital boundaries compatible with geographic information systems. The methods we employed to create these data will be useful to inform similar efforts in other jurisdictions and the data have many public health applications as well as being informative for water/environmental research and infrastructure projects.

Wastewater Testing and Detection of Poliovirus Type 2 Genetically Linked to Virus Isolated from a Paralytic Polio Case - New York, March 9-October 11, 2022

In July 2022, a case of paralytic poliomyelitis resulting from infection with vaccine-derived poliovirus (VDPV) type 2 (VDPV2)§ was confirmed in an unvaccinated adult resident of Rockland County, New York (1). As of August 10, 2022, poliovirus type 2 (PV2)¶ genetically linked to this VDPV2 had been detected in wastewater** in Rockland County and neighboring Orange County (1). This report describes the results of additional poliovirus testing of wastewater samples collected during March 9-October 11, 2022, and tested as of October 20, 2022, from 48 sewersheds (the community area served by a wastewater collection system) serving parts of Rockland County and 12 surrounding counties. Among 1,076 wastewater samples collected, 89 (8.3%) from 10 sewersheds tested positive for PV2. As part of a broad epidemiologic investigation, wastewater testing can provide information about where poliovirus might be circulating in a community in which a paralytic case has been identified; however, the most important public health actions for preventing paralytic poliomyelitis in the United States remain ongoing case detection through national acute flaccid myelitis (AFM) surveillance†† and improving vaccination coverage in undervaccinated communities. Although most persons in the United States are sufficiently immunized, unvaccinated or undervaccinated persons living or working in Kings, Orange, Queens, Rockland, or Sullivan counties, New York should complete the polio vaccination series as soon as possible.

Wastewater treatment plant operators report high capacity to support wastewater surveillance for COVID-19 across New York State, USA

Wastewater surveillance for infectious disease expanded greatly during the COVID-19 pandemic. As a collaboration between sanitation engineers and scientists, the most cost-effective deployment of wastewater surveillance routinely tests wastewater samples from wastewater treatment plants. To evaluate the capacity of treatment plants of different sizes and characteristics to participate in surveillance efforts, we developed and distributed a survey to New York State municipal treatment plant supervisors in the summer and fall of 2021. The goal of the survey was to assess the knowledge, capacity, and attitudes toward wastewater surveillance as a public health tool. Our objectives were to: (1) determine what treatment plant operators know about wastewater surveillance for public health; (2) assess how plant operators feel about the affordability and benefits of wastewater surveillance; and (3) determine how frequently plant personnel can take and ship samples using existing resources. Results show that 62% of respondents report capacity to take grab samples twice weekly. Knowledge about wastewater surveillance was mixed with most supervisors knowing that COVID-19 can be tracked via wastewater but having less knowledge about surveillance for other public health issues such as opioids. We found that attitudes toward wastewater testing for public health were directly associated with differences in self-reported capacity of the plant to take samples. Further, findings suggest a diverse capacity for sampling across sewer systems with larger treatment plants reporting greater capacity for more frequent sampling. Findings provide guidance for outreach activities as well as important insight into treatment plant sampling capacity as it is connected to internal factors such as size and resource availability. These may help public health departments understand the limitations and ability of wastewater surveillance for public health benefit.

Linking metal (Pb, Hg, Cd) industrial air pollution risk to blood metal levels and cardiovascular functioning and structure among children in Syracuse, NY

BACKGROUND

Exposure to air pollution has been linked to individual health effects in occupational environments and communities proximate to air pollution sources. Use of estimated chemical concentrations from the Risk Screening Environmental Indicators (RSEI) model, derived from the Toxics Release Inventory, can help approximate some contributions to individual lifetime exposure to risk from air pollution and holds potential for linkages with specific health outcome data.

OBJECTIVES

Our objectives were: (1) use regression modeling to test for associations between observed blood metal concentrations in children and RSEI total air concentrations of the same metals released from proximate manufacturing facilities; (2) determine the relative contribution of RSEI air pollution to blood metal concentrations; and (3) examine associations between chronic metal exposure and cardiovascular functioning and structure in study participants.

METHODS

Using data synthesis methods and regression modeling we linked individual blood-based levels of lead, mercury, and cadmium(Pb, Hg, Cd) and cardiovascular functioning and structure to proximate industrial releases of the same metals captured by the Environmental Protection Agency's (EPA) RSEI geographic microdata.

RESULTS

We found that RSEI-derived ground-level ambient air concentrations of Hg and Cd were a significant predictor of blood metal levels, when controlling for covariates and other exposure variables. In addition to associations with blood metal findings, RSEI concentrations also predicted cardiovascular dysfunction and risk including changes in left-ventricular mass, blood pressure, and heart rate.

DISCUSSION

Right-to-know data, such as EPA's RSEI, can be linked to objective health outcomes, rather than simply serving as a non-specific risk estimate. These data can serve as a proxy for hazard exposure and should be used more widely to understand the dynamics of environmental exposure. Furthermore, since these data are both a product of and contribute to regulatory decision making, they could serve as an important link between disease risk and translation-orientated national environmental health policy.

Air quality changes in New York City during the COVID-19 pandemic

In December 2019, a new, severe coronavirus (COVID-19) appeared in Wuhan, China. Shortly after, the first COVID-19 case was confirmed in the United States. The emergence of this virus led many United States governors to enact executive orders in an effort to limit the person-to-person spread of the virus. One state that utilized such measures was New York, which contains New York City (NYC), the most populous city in the United States. Many reports have shown that due to the government-backed shutdowns, the air quality in major global cities improved. However, there has been only limited work on whether this same trend is seen throughout the United States, specifically within the densely populated NYC area. Thus, the focus of this study was to examine whether changes in air quality were observed in NYC resulting from New York State's COVID-19-associated shutdown measures. To do this, daily concentrations of fine particulate matter (PM_2.5) and nitrogen dioxide (NO₂) were obtained from 15 central monitoring stations throughout the five NYC boroughs for the first 17 weeks (January through May) of 2015-2020. Decreases in PM_2.5 (36%) and NO₂ (51%) concentrations were observed shortly after the shutdown took place; however, using a linear time lag model, when changes in these pollutant concentrations were compared to those measured during the same span of time in 2015-2019, no significant difference between the years was found. Therefore, we highlight the importance of considering temporal variability and long-term trends of pollutant concentrations when analyzing for short-term differences in air pollutant concentrations related to the COVID-19 shutdowns.

Simulation of low temperature anaerobic digestion of dairy and swine manure

The data reported by L.M. Safley, P.W. Westerman [Bioresource Technology 47 (2) (1994) 165-171] from the laboratory digestion of dairy and swine manure at psychrophilic temperatures (i.e., 10-23 degrees C) have been used to determine the response of the latest comprehensive dynamic mathematical model of methanogenesis [D.T. Hill, S.A. Cobb, Transactions of the ASAE 39 (2) (1996) 565-573] in this low temperature range. Extensive performance data from digesters using animal waste in this temperature range have been lacking, thus allowing limited validation of the comprehensive model. The results of the comprehensive model simulations were compared with the actual data reported by Safley and Westerman (loc. cit.) and with their empirical regression models. Results indicate that the comprehensive model is as accurate as Safley and Westerman's models for three of the four cases reported, but shows a great dissimilarity for the fourth case.

Potent nonpeptide angiotensin II receptor antagonists. 2. 1-(Carboxybenzyl)imidazole-5-acrylic acids

The further evolution of the imidazole-5-acrylic acid series of nonpeptide angiotensin II receptor antagonists is detailed (for Part 1, see: J. Med. Chem. 1992, 35, 3858). Modifications of the N-benzyl ring substitution were undertaken in an effort to mimic the Tyr4 residue of angiotensin II. Introduction of a p-carboxylic acid on the N-benzyl ring resulted in the discovery of compounds with nanomolar affinity for the receptor and good oral activity. SAR studies of these potent antagonists revealed that the thienyl ring, the (E)-acrylic acid, and the imidazole ring in addition to the two acid groups were important for high potency. Also, overlay comparisons of the parent diacid with both angiotensin II and a representative biphenylyltetrazole nonpeptide angiotensin II receptor antagonist are presented. The parent diacid analog, SK&F 108566 or (E)-3-[2-butyl-1-(4-carboxybenzyl)-1H-imidazole-5-yl]-2-[(2- thienyl)methyl]propenoic acid, is currently in clinical development for the treatment of hypertension.

Imidazole-5-acrylic acids: potent nonpeptide angiotensin II receptor antagonists designed using a novel peptide pharmacophore model

A series of novel nonpeptide angiotensin II receptor antagonists containing a substituted (E)-acrylic acid has been developed. The overlay of 1, an imidazole-5-acetic acid found in the patent literature, on a novel pharmacophore model of AII suggested that extension of the acid side chain and attachment of a second aryl residue to mimic the C-terminal phenylalanine region of AII would lead to increased activity. A study of extended acid side chains at C-5 of the imidazole nucleus led to the discovery of the (E)-acrylic acid 5 as a promising starting point for further exploration. As predicted by the modeling, substitution of a benzyl group on the acrylic acid side chain to mimic the phenylalanine gave increased potency. An extensive study of the SAR of the newly introduced aromatic ring revealed that electron-rich heteroaryl rings provided improved activity, most notably in the in vivo rat models. Compound 40, (E)-3-[2-butyl-1- [(2-chlorophenyl)methyl]imidazol-5-yl]-2-[(2-thienyl)methyl]-2- propenoic acid, has been shown to be a potent, competitive, and orally active small molecule AT-1 receptor antagonist. It exhibits a 2 orders of magnitude increase in binding affinity and a 10-fold improvement in in vivo potency as compared to compound 1 and represents an important milestone in the development of even more potent nonpeptide angiotensin II receptor antagonists.

Characterization of renal angiotensin II receptors using subtype selective antagonists

Two angiotensin II (AII) receptor subtypes, AT1 and AT2, have recently been identified based on their relative affinities for selective peptide and nonpeptide antagonists. In the present study we used various AII peptide analogs, the AT1 subtype selective antagonists, DuP 753 and SK&F 108566, and the AT2 subtype selective antagonists, WL-19 and CGP 42112A, to determine whether AII receptor subtypes exist in the kidney. In agreement with previous studies, octapeptide (Sar1,Ile8-AII) and heptapeptide (AIII and Ile8-AIII) AII analogs displaced [125I]AII bound to rat glomerular membranes with similar affinities. However, in membranes derived from cortical tubules and the outer medulla, the heptapeptide analogs were 20-fold less potent in competing with [125I]AII binding than octapeptide analogs. The AT1 subtype selective nonpeptide AII antagonists, DuP 753 and SK&F 108566, totally displaced [125I]AII binding from all three membrane preparations in a monophasic manner with IC50 values in the 5 to 30 nM range. The AT2 selective peptide antagonist, CGP 42112A, had a low affinity in AII three membranes (IC50 = 450-1050 nM), whereas the nonpeptide AT2 selective antagonist, WL-19, had no activity at concentrations up to 10 microM. Dithiothreitol and the nonhydrolyzable GTP analog, 5'-guanylyl-imidodiphosphate, inhibited AII binding to all three membrane preparations. Based on these results, we conclude that the AII receptors located on glomeruli, tubules and in the outer medulla belong to the AT1 subtype, and that the physiologically important renal actions of AII are mediated through activation of AT1 receptors.

Cytotoxicity and antitumor activity of some tetrahedral bis(diphosphino)gold(I) chelates

We report the cytotoxicity toward B16 cells and antitumor activity in three transplantable tumor models of a series of ionic, tetrahedral, bischelated gold diphosphine complexes of the type [Au1(R2PYPR2')2]X, where Y = (CH2)2, (CH2)3, or cis-CH = CH. The anion (X = Cl, Br, I, CH3SO3, NO3, PF6) had little effect upon activity. The R = R' = phenyl complexes 1, 7, and 8 [Y = (CH2)2, (CH2)3, cis-CH = CH, X = Cl] were the most active against P388 leukemia, with an increase in lifespan ranging from 83 to 92% and were also active against M5076 sarcoma and B16 melanoma. Complexes with pyridyl or fluorophenyl substituents had reduced activities. For the latter, 19F and 31P NMR were used to verify the formation of bischelated gold(I) complexes in solution. The reduced activity of the complex with R = Et and R' = Ph and inactivity with R = R' = Et are discussed in terms of their increased reactivity as reducing agents. 31P NMR studies show that [AuI(Et2P(CH2)2PPh2)2]Cl readily reacts with serum, albumin, and Cu2+ ions to give oxidized ligand.

Interactions of porphyrins with purified DNA and more highly organized structures

Studies of the solution properties of gold(III)tetrakis(4-N-methylpyridyl) porphine and its DNA binding characteristics have been conducted utilizing uv/vis absorption spectroscopy, circular dichroism (CD), Mossbauer spectroscopy, and temperature-jump relaxation techniques. These studies indicate that over the concentration range considered this water soluble gold(III) porphyrin does not aggregate, binds axial ligands only weakly with a preference for soft Lewis bases, and is capable of intercalation into nucleic acids of appropriate base pair content. The interaction of this and several other porphyrins with the synthetic polynucleotide poly(dA-dC).poly(dT-dG) has been studied. Spectroscopic signatures for intercalation were found for those derivatives not having axial ligands. Intercalation into chromatin in vitro can also occur with those porphyrins and metalloporphyrins which do not have axial ligands. Finally, studies utilizing microinjection techniques indicate that once within the cell, tetrakis(4-N-methylpyridyl)porphine tends to localize in the nucleus.

Antitumor activity of bis(diphenylphosphino)alkanes, their gold(I) coordination complexes, and related compounds

Bisphosphines related to bis(diphenylphosphino)ethane (dppe) and their gold complexes are described that are active in a spectrum of transplantable tumor models. When administered ip on days 1-5 at its maximally tolerated dose (MTD) of 40 mumol/kg, dppe reproducibly gives 100% increase in life span (ILS) in mice bearing ip P388 leukemia. Coordination of chlorogold(I) to each phosphine in dppe gave a complex that had similar activity but at a much lower dose level than dppe; the MTD for the gold(I) complex was 7 mumol/kg. Among other metal complexes of dppe, the Au(III) complex was active (greater than 50% ILS) whereas Ag(I), Ni(II), Pt(II), Pd(II), and Rh(I) complexes were inactive. Among dppe analogues, replacement of phenyl groups with ethyl or benzyl groups resulted in inactivity for both ligands and the corresponding gold complexes whereas substitution with cyclohexyl or heterocyclic ring systems yielded ligands and/or gold complexes with antitumor activity. Among substituted-phenyl dppe and dppe(AuCl)2 analogues, 3-fluoro, 4-fluoro, perdeuterio, 4-methylthio, and 2-methylthio analogues were active; 4-methyl, 3-methyl, 4-methoxy, 4-dimethylamino, and 4-trifluoromethyl analogues were marginal or inactive. Analogues in which the ethane bridge of dppe or dppe(AuCl)2 was varied between one and six carbons, unsaturated or substituted, revealed that activity was maximal with ethane or cis-ethylene. Compounds with good P388 activity were also active in other animal tumor models.

Cellular pharmacology of mu-[1,2-bis(diphenylphosphino)ethane]bis[(1-thio-beta-D-gluco pyranosato-S)gold(I)]: a novel antitumor agent

SK&F 102912 (mu-[1,2-bis(diphenylphosphino)ethane]bis[(1-thio-beta-D- glucopyranosato-S)gold(I)], [(Autg)2(dppe)]) has shown reproducible and significant activity in transplantable murine tumor models and represents a structurally unique class of antineoplastic agents. A number of in vitro studies were performed to elucidate the cellular pharmacology of this gold-containing complex. [(Autg)2(dppe)] is a potent cytotoxic agent in vitro as demonstrated by its ability to inhibit the clonogenic capacity of a variety of tumor cell lines following a brief exposure to the drug. Cell-cycle analysis using HL-60 cells showed that low concentrations (2 microM) of [(Autg)2(dppe)] induced an S-phase block and higher concentrations induced a secondary block at the G1/S boundary. [(Autg)2(dppe)] had several effects on DNA metabolism and structure including preferential inhibition in cells of DNA synthesis (relative to RNA and protein synthesis) and the production of DNA single- and double-strand breaks as measured by alkaline elution. The cytoxic mechanism of this gold complex appears to be distinct from that of the monophosphine-gold complex auranofin.

Digestibility and utilization of energy and protein in screened swine waste solids by gestating gilts

Two balance experiments were conducted using 24 gestating gilts in each experiment to determine the apparent digestible and metabolizable energy content, apparent digestible protein content, net protein utilization and apparent biological value of screened swine waste solids (SSWS). Waste solids were collected by screening flushed whole swine waste using a vibrating screen separator. Waste solids containing 30% dry matter were collected daily and mixed with a basal diet. In Exp. 1, SSWS were fed at a level estimated to replace 0, 25, 50 or 86% of the metabolizable energy content of the basal diet. Digestibility of the energy in the total diet decreased quadratically (85.2, 70.2, 60.7 and 58.3%, respectively, P less than .0001) with increasing SSWS. The percentages of gross energy supplied by SSWS that were digested and metabolized, as calculated by difference, were not affected significantly by the amount of SSWS fed (48.0, 48.0, 53.2% digested and 45.1, 45.2, 48.1% metabolized, respectively, for 25, 50 and 86% of gross energy intake from SSWS). The mean digestible and metabolizable energy contents of SSWS for gestating gilts were determined to be 1,998 and 1,854 kcal/kg dry matter. In Exp. 2, gilts were fed SSWS to replace 0, 25 or 50% of the crude protein in the basal diet. Apparent digestibility of the protein in the total diet decreased linearly (83.8, 66.1 and 51.1%, respectively, P less than .0001) as the amount of SSWS in the diet increased. The apparent digestibility of the crude protein in SSWS, as calculated by difference, was -4.23 and 10.1% for the 25 and 50% level of replacement.(ABSTRACT TRUNCATED AT 250 WORDS)

Interactions of gold coordination complexes with DNA

The interactions of certain gold(I) and gold(III) complexes with isolated plasmid pBR322 DNA were defined and compared to those of cis-diamminedichloroplatinum(II), CDDP, using an agarose gel electrophoresis assay. Trichloro(pyridine)gold(III) appeared to bind to DNA as evidenced by its ability to produce dose-dependent changes in the electrophoretic mobilities of closed circular, supercoiled, closed circular, relaxed, and open circular plasmid DNAs. These effects suggest that the gold containing complex induces conformational changes in the plasmid as a result of the compound binding to the DNA and the subsequent unwinding of the double helix and shorting of the DNA. Auranofin [(2,3,4,6-tetra-O-acetyl-1-thio-beta-D-glucopyranosato-S)-triethyl phosphine gold(I)] did not appear to interact with DNA under any conditions. However, its analog chloro(triethylphosphine) gold(I) interacted with DNA at pH 9.5 in borate buffer and produced electrophoretic mobility changes in pBR322 DNA which were different from those produced by the gold(III) complexes that were evaluated. Binding of chloro(triethylphosphine) gold(I) was inhibited by the co-addition of the thiosugar portion of auranofin suggesting preferential binding of the gold moiety to thiosugar, which results in the production of auranofin (or a sugar containing) gold complex and inhibition of gold binding to DNA. The interactions of a number of gold compounds with DNA were also evidenced by their abilities to inhibit the binding of ethidium bromide to DNA. The results from these studies indicate that: gold containing complexes can bind to, and produce conformational changes in, DNA; gold(I) and gold(III) complexes may interact with DNA via different chemical mechanisms to produce different conformational changes in DNA; and certain coordinating ligands in gold complexes (e.g. Cl, Br and SCN) can be exchanged for binding sites on DNA by gold.

Correlation of the in vitro cytotoxic and in vivo antitumor activities of gold(I) coordination complexes

A series of gold(I) coordination complexes including analogues of the antiarthritic agent auranofin 1 were evaluated for in vitro cytotoxic potency against both B16 melanoma cells and P388 leukemia cells and in vivo antitumor activity against P388 leukemia in mice. A number of the complexes showed potent cytotoxic activity in vitro and antitumor activity in vivo, with the phosphine-coordinated gold(I) thiosugar complexes demonstrating the greatest in vitro and in vivo activity. The data compiled for 63 complexes of the general structural formula LAuX provide the basis for the following observations: potent in vitro cytotoxic activity is observed for substituted (phosphine) gold complexes, lack of potency in vitro correlates well with lack of antitumor activity, potent cytotoxicity in vitro is not necessarily predictive of activity in vivo, in vivo antitumor activity is generally optimized by ligation of Au(I) with a substituted phosphine and a thiosugar.

5,6-Diaryl-2,3-dihydroimidazo[2,1-b]thiazoles: a new class of immunoregulatory antiinflammatory agents

A series of substituted 5,6-diaryl-2,3-dihydroimidazo[2,1-b]thiazoles were synthesized and evaluated in the rat adjuvant-induced arthritis and mouse oxazolone-induced contact sensitivity assays to determine the potential of these compounds for use as immunoregulatory antiinflammatory agents. This class of compounds was derived by combining salient structural features of the antiinflammatory agent flumizole and the immunoregulatory drug levamisole. Unlike the latter two, a number of compounds in the target series were found to possess the desired combination of activities. Exploration of structure-activity relationships in the adjuvant-induced arthritic rat assay revealed that optimal potency was exhibited by symmetrically substituted 5,6-diaryl compounds having one of the following alkyl heteroatom or halogen functions at the para position: methoxy, ethoxy, methylthio, N-ethyl-N-methylamino, fluoro, or chloro. Scrambling of these two substituent classes to yield the asymmetrically substituted 5,6-diaryl compounds resulted in potent activity only with the 5-alkyl heteroatom, 6-halo-substituted regioisomers. However in the oxazolone-induced contact sensitivity assay, no consistent relationship of variation in activity with structural change was apparent. The initial target compound 5,6-bis(4-methoxyphenyl)-2,3-dihydroimidazo[2,1-b]thiazole (1) was compared with its progenitors in additional models of inflammation and immunoregulation.

1,3-Diaryltriazenes: a new class of anorectic agents

A series of substituted 1,3-diaryltriazenes has been synthesized and tested for anorectic activity. Several members of the series were effective; one compound, 1,3-bis[2-cyano-5-(trifluoromethyl)phenyl]triazene, was particularly active, causing weight loss in rats, dogs, and squirrel monkeys. It was devoid of overt central nervous system activity, and compared to previously reported biologically active triazenes, it was relatively nontoxic up to 30 days of drug administration.

Imidodisulfamides. 2. Substituted 1,2,3,4-tetrahydroisoquinolinylsulfonic imides as antagonists of slow-reacting substance of anaphylaxis

As part of a study of the influence of structural modifications of N',N'-bis(aralkyl)imidodisulfamides on their ability to selectively antagonize SRS-A activity, a few conformationally constrained structures were examined. Among these derivatives having a conformationally restricted alkylene side chain, substituted 1,2,3,4-tetrahydroisoquinolinylsulfonic imides produced optimum SRS-A antagonist activity and selectivity. These compounds were tested for antagonism of partially purified SRS-A induced contractions of isolated guinea pig ileum. In this series of tetrahydroisoquinolines, the effect of aromatic ring substitution, as well as substitution and variation of the size of the heterocyclic ring on SRS-A antagonist activity and selectivity, was studied.