Evaluation of Complex Mixture Toxicity in the Milwaukee Estuary (WI, USA) Using Whole-Mixture and Component-Based Evaluation Methods

Anthropogenic activities introduce complex mixtures into aquatic environments, necessitating mixture toxicity evaluation during risk assessment. There are many alternative approaches that can be used to complement traditional techniques for mixture assessment. Our study aimed to demonstrate how these approaches could be employed for mixture evaluation in a target watershed. Evaluations were carried out over 2 years (2017-2018) across 8-11 study sites in the Milwaukee Estuary (WI, USA). Whole mixtures were evaluated on a site-specific basis by deploying caged fathead minnows (Pimephales promelas) alongside composite samplers for 96 h and characterizing chemical composition, in vitro bioactivity of collected water samples, and in vivo effects in whole organisms. Chemicals were grouped based on structure/mode of action, bioactivity, and pharmacological activity. Priority chemicals and mixtures were identified based on their relative contributions to estimated mixture pressure (based on cumulative toxic units) and via predictive assessments (random forest regression). Whole mixture assessments identified target sites for further evaluation including two sites targeted for industrial/urban chemical mixture effects assessment; three target sites for pharmaceutical mixture effects assessment; three target sites for further mixture characterization; and three low-priority sites. Analyses identified 14 mixtures and 16 chemicals that significantly contributed to cumulative effects, representing high or medium priority targets for further ecotoxicological evaluation, monitoring, or regulatory assessment. Overall, our study represents an important complement to single-chemical prioritizations, providing a comprehensive evaluation of the cumulative effects of mixtures detected in a target watershed. Furthermore, it demonstrates how different tools and techniques can be used to identify diverse facets of mixture risk and highlights strategies that can be considered in future complex mixture assessments. Environ Toxicol Chem 2023;42:1229-1256. © 2023 SETAC.

Rheology of saliva in health and disease

BACKGROUND: Saliva is a complex fluid that lubricates the oropharynx and facilitates chewing, swallowing, and vocalization. Viscoelasticity is critical for the ability of saliva to fulfill these functions. Xerostomia, or a sensation of dry mouth, occurs in 17–26% of the population. Although many equate xerostomia with hyposalivation, high-risk patients frequently report oral dryness in the absence of decreased salivary flow. OBJECTIVE: This study aims to determine if xerostomia is associated with alterations in the rheological properties of saliva in addition to decreased salivary production. METHODS: The study population included patients with post-radiation xerostomia, patients with anticholinergic-induced xerostomia and healthy controls. Salivary volumetric flow rate was measured, shear viscosity was measured using oscillatory rheometry, and extensional viscosity was measured using capillary thinning methods. Groups were compared using descriptive statistics and univariate analysis. RESULTS: A total of 36 subjects were included: 15 with post-radiation xerostomia, 9 with anticholinergic-induced xerostomia and 12 controls. Salivary volumetric flow was significantly decreased in post-radiation and anticholinergic-induced patients compared to controls. On capillary thinning testing, saliva from xerostomia patients had significantly greater extensional viscosity compared to controls. However, saliva from the three groups showed no significant difference in the complex viscosity or the storage or loss modulus of saliva with oscillatory rheology. CONCLUSIONS: Xerostomia is associated with decreased salivary volumetric flow and quantitative changes in the rheologic properties of saliva.

The use of bayesian inversion to resolve plasma equilibrium

Recently, bayesian probability theory has been used at a number of experiments to fold uncertainties and interdependencies in the diagnostic data and forward models, together with prior knowledge of the state of the plasma, to increase accuracy of inferred physics variables. A new probabilistic framework, MINERVA, based on bayesian graphical models, has been used at JET and W7-AS to yield predictions of internal magnetic structure. A feature of the framework is the bayesian inversion for poloidal magnetic flux without the need for an explicit equilibrium assumption. Building on this, we discuss results from a new project to develop bayesian inversion tools that aim to (1) distinguish between competing equilibrium theories, which capture different physics, using the MAST spherical tokamak, and (2) test the predictions of MHD theory, particularly mode structure, using the H-1 Heliac. Specifically, we report on correction of the motional Stark effect, pickup coils, flux-loop constrained bayesian inferred equilibrium for varying toroidal flux.

A novel gene cluster in Fusarium graminearum contains a gene that contributes to butenolide synthesis

The development of expressed sequence tag (EST) databases, directed transformation and a sequenced genome has facilitated the functional analysis of Fusarium graminearum genes. Extensive analysis of 10,397 ESTs, derived from thirteen cDNA libraries of F. graminearum grown under diverse conditions, identified a novel cluster of eight genes (gene loci fg08077-fg08084) located within a 17kb region of genomic sequence contig 1.324. The expression of these genes is concomitantly up-regulated under growth conditions that promote mycotoxin production. Gene disruption and add-back experiments followed by metabolite analysis of the transformants indicated that one of the genes, fg08079, is involved in butenolide synthesis. The mycotoxin butenolide is produced by several Fusarium species and has been suggested, but not proven, to be associated with tall fescue toxicoses in grazing cattle. This is the first report of the identification of a gene involved in the biosynthetic pathway of butenolide.

The 3rd international intercomparison on EPR tooth dosimetry: Part 1, general analysis

The objective of the 3rd International Intercomparison on Electron Paramagnetic Resonance (EPR) Tooth Dosimetry was the evaluation of laboratories performing tooth enamel dosimetry below 300 mGy. Participants had to reconstruct the absorbed dose in tooth enamel from 11 molars, which were cut into two halves. One half of each tooth was irradiated in a 60Co beam to doses in the ranges of 30-100 mGy (5 samples), 100-300 mGy (5 samples), and 300-900 mGy (1 sample). Fourteen international laboratories participated in this intercomparison programme. A first analysis of the results and an overview of the essential features of methods applied in different laboratories are presented. The relative standard deviation of results of all methods was better than 27% for applied doses in the range of 79-704 mGy. In the analysis of the unirradiated tooth halves 8% of the samples were identified as outliers with additional absorbed dose above background dose.

The Advanced Glaucoma Intervention Study (AGIS): 10. Variability among academic glaucoma subspecialists in assessing optic disc notching

PURPOSE

An analysis of data from the Advanced Glaucoma Intervention Study (AGIS) has found eyes reported to have partial optic disc rim notching (not to the edge) at baseline to have less risk of subsequent visual field loss than eyes with no notching. Because this is counterintuitive and because classification of notching had not been defined in the AGIS protocol, we have assessed AGIS ophthalmologists interobserver and intraobserver agreement on notching.

METHODS

Fourteen glaucoma subspecialists classified notching in 26 pairs of stereoscopic disc photographs of eyes with mild to severe glaucomatous optic neuropathy. They classified images as showing either no notching, notching not to the edge, or notching to the edge. Several hours later, 10 of them classified the same images a second time.

RESULTS

In an analysis of interobserver agreement, of 26 stereoscopic images, a plurality of ophthalmologists classified notching as absent in 9 (35%), as present but not to the edge in 7 (27%), and as present and not to the edge in 10 (38%). All 14 ophthalmologists (100%) agreed on the classification of 7 (27%) of the images, and 13 of the 14 ophthalmologists (93%) agreed on the classification of 4 additional images (15%). Of these 11 images with at least 93% agreement, notching was reported as absent in 3 (27%) and to the edge in 8 (73%). In the remaining 15 images, there was substantial disagreement about whether notching was present and, if so, whether it was to the edge. In an analysis of intraobserver agreement, none of the 10 ophthalmologists who completed the viewing a second time classified all eyes exactly the same as the first time, though 5 ophthalmologists made 4 or fewer reclassifications. Overall, 80% of the original classifications were reproduced on second reading. Of the initial classifications that were not reproduced, slightly more than half were first classified as having notching not to the edge.

CONCLUSION

Without definitions or examples of optic disc rim notching, the glaucoma subspecialists had relatively high intraobserver agreement but were likely to disagree with each other in characterizing the degree of disc rim notching. We recommend development of a standard photographic classification of disc rim notching. The classification should be tested for inter- and intra-observer agreement.

Purification and characterization of a common soil component which inhibits the polymerase chain reaction

DNA prepared from soil usually contains a brown-tinted inhibitor of the polymerase chain reaction (PCR) which limits the sensitivity of this technique for specific detection of microorganisms. To localize the inhibitor, soil fractions were tested for their inhibitory effect on the PCR reaction. A highly inhibitory activity, sufficient to account for the inhibition typically exhibited by soil DNA, was found to be tightly associated with the soil microorganism fraction. After cell breakage, the inhibitory material became soluble, and was not separable from DNA by standard purification procedures. A method was derived by which most of the inhibitory material could be selectively solubilized from the microorganism fraction without cell breakage, using successive washes with buffers differing in EDTA concentration. This technique was used to isolate a substance with characteristics suggesting that it is the major PCR inhibitor contaminating DNA purified from soil. It was found to be an organic, water-soluble compound of high molecular weight, and was present in a variety of soil types from different locations. It was found to be distinctly different in its solubility properties from humic and fulvic acids, and also in its FT-IR and NMR spectra. It forms a complex with protein and may inhibit the PCR reaction by an interaction with Taq DNA polymerase.

Methylphenidate in early poststroke recovery: a double-blind, placebo-controlled study

OBJECTIVE

To determine the efficacy and safety of methylphenidate in acute stroke rehabilitation.

DESIGN

A prospective, randomized, double-blind, placebo-controlled study.

PATIENTS AND SETTING

Twenty-one stroke patients consecutively admitted to a community-based rehabilitation unit.

INTERVENTION

Three-week treatment of methylphenidate (or placebo) in conjunction with physical therapy. Methylphenidate was started at 5mg and increased gradually to 30mg (15mg at 8:00AM and 15mg at 12:00 noon), and discontinued before discharge.

MAIN OUTCOME MEASURES

Mood measures included the Hamilton Depression Rating Scale (HAM-D) and Zung Self-Rating Depression Scale (ZDS). Cognitive status was evaluated using the Mini-Mental State Exam (MMSE). Motor functioning was assessed using the Fugl-Meyer Scale (FMS) and a modified version of the Functional Independence Measure (M-FIM). All measures were administered pretreatment and weekly thereafter. Side effects were measured after each increase in dosage and weekly.

RESULTS

Patients receiving methylphenidate treatment scored lower on the HAM-D (F(1,18)=5.714, p=.028), lower on the ZDS (F(1,18)=4.206, p=.055), higher on the M-FIM (F(1,18)=5.374, p=.032), and higher on the FMS (F(1,9)=4.060, p=.075) than patients receiving placebo.

CONCLUSION

Methylphenidate appears to be a safe and effective intervention in early poststroke rehabilitation that may expedite recovery.

Synthesis of phosphotyrosine-containing peptides using bis-(2,2,2-trichloro)ethyl groups for phosphate protection

Suitability of bis-(2,2,2-trichloro)ethyl (Tc) groups for protection of phosphate moiety in Boc-mode synthesis of phosphotyrosine peptides is demonstrated Boc-Tyr(PO3Tc2)-OH and Fmoc-Tyr(PO3Tc2)-OH were prepared by acylating H-Tyr(PO3Tc2)-OH with (Boc)2O and Fmoc-ONSu, respectively. Phosphorus introduction was achieved by phosphorylating Boc-Tyr-OBzl with Tc phosphochloride. The Tc-phosphorus protector was found to be incompatible with the Fmoc group because the conditions of Fmoc removal (piperidine treatment) caused dephosphorylation. Complete NMR spectral assignments in the described compounds is presented. (Contribution No. 2398 from the Centre for Food and Animal Research).

Methylphenidate dosing: twice daily versus three times daily

OBJECTIVE

To evaluate the short-term efficacy and side effects associated with two methylphenidate hydrochloride (MPH) dosing patterns.

METHODS

Twenty-five boys with attention deficit hyperactivity disorder (ADHD) participated in a 5-week, triple-blind, placebo-controlled, crossover evaluation of MPH administered twice (b.i.d.) versus thrice (t.i.d.) per day (mean dose = 8.8 +/- 5 mg, .30 +/- .1 mg/kg/dose). Four dosing conditions (placebo, titration [gradual increase to target dose], b.i.d., and t.i.d.) were used. Dependent measures obtained on a weekly basis included: parent and teacher ratings of child behavior, parent-child conflicts, parent report of stimulant side effects, child self-report of mood symptoms, a sleep log, laboratory measures of attention, and actigraphic recording of sleep activity.

RESULTS

All dosing conditions resulted in significant effects on ADHD symptoms when compared with baseline. Relative to placebo, t.i.d. dosing was characterized by improvement on the greatest number of behavioral measures, and both b.i.d. and t.i.d. were generally more effective than titration. Direct comparisons of b.i.d. and t.i.d. dosing revealed that t.i.d. was associated with greater improvement on the Conners Parent Rating Scale Impulsivity/Hyperactivity factor, with a similar marginally significant effect for the ADD-H Teacher Rating Scale Hyperactivity factor. The analysis of clinically significant change favored a three-times-a-day dosing schedule over placebo on both parent and teacher ratings of impulsivity/hyperactivity and attention. Compared with placebo, appetite suppression was rated, on average, as more severe in the t.i.d. and titration conditions, but not in the b.i.d. condition. However, the number of subjects who exhibited any or severe appetite suppression did not differ significantly between the b.i.d. and t.i.d. schedules. Although there was no difference in sleep duration for children on b.i.d. and t.i.d. schedules, total sleep time appeared to decrease slightly on t.i.d. relative to placebo according to both parent ratings and actigraphic assessment. There were no significant differences between b.i.d. and t.i.d. on any other side effects or sleep variables.

CONCLUSIONS

For many children with ADHD, t.i.d. dosing may be optimal. There are few differences in acute side effects between b.i.d. and t.i.d. MPH dosing. The dosing schedule should be selected according to the severity and time course of ADHD symptoms rather than in anticipation of dosing schedule-related side effects.

The primary care of patients who have bodily concerns

A conceptual and clinical approach was developed as a high-quality, economically responsible alternative to the often unsatisfactory approach to patients described as somatizers or hypochondriacs. This approach encourages primary care practitioners to respond in a way that can be mutually satisfying to themselves and their patients who have bodily concerns.

Epidemiology and prevention of blood and body fluid exposures among emergency department staff

Emergency Department (ED) staff are vulnerable to occupational exposure to infectious blood and body fluids (BBF). Universal precautions are often ignored in the ED setting. Identification of body locations at high risk of BBF exposure may allow development of site specific protective garments that minimize risk and inconvenience. All permanent staff (92) in a 58,000 visit public university hospital ED with potential for BBF exposure were surveyed. Respondents estimated the number of BBF contacts sustained during the past year, describing their most recent contact in detail. Seventy-eight of 91 (85%) responded, reporting average rates of 54.1 intact skin, 1.5 nonintact skin, and .87 mucous membrane BBF contacts per full-time employee per year. Of the most recent incidents, 94% involved blood, 22% involved vomit or urine, and 11% involved saliva. Eighty-eight percent of BBF contacts were to unprotected skin or mucous membranes, either when no barrier was worn or at the gap between gloves and sleeves. Most (66%) were distal to the elbow; 13% involved the face. Use of long gloves or another continuous protective barrier from the fingers to the elbow, in addition to increased use of face masks or shields, would markedly reduce the rate of ED BBF contacts with a minimum of inconvenience.

DNA testing and genetic counseling: truth or consequences

Advances in medical genetics are providing a major clinical challenge to practitioners seeing patients concerned about their risk of developing either inherited disease or susceptibility to acquired disease. Popular information can easily exceed our professional ability to provide services to well-read patients who want answers with scientific certainty. The challenge also involves ethical questions regarding confidentiality and the way that results are disclosed. More often than not, the test itself becomes the focus of psychosocial expectations for the future and lifestyle of the patient and family. The behavioral consequences of disclosure of test results need to be anticipated by the caregiver to avoid adverse psychological outcomes.

Sick-role susceptibility. A commentary on the contemporary data base (1989-1991) and classification system

A brief review of the historical and current status of the 'sick-role' concept is followed by an extensive literature survey of 526 articles published on the sick role since 1989. The commentary discusses measurement and research issues and then examined the areas of enquiry and trends from a biological, psychological, social and cultural perspective. Questions are raised about the significance of the data base from the view-point of classification and treatment. A descriptive and therapeutic model is proposed.

Compliance

Compliance is an ancient topic subjected to intense recent scrutiny as a result of scientific and social changes which focus on lifestyle adjustment to chronic illness and emphasize increasing patient involvement in self-care. Difficulties in definition, measurement and research design as well as the complexity of the problems contribute to conflicting findings and a lack of consensus about determinants of compliance. Five conceptual models have been studied but only a few positive and negative factors have been consistently identified, perhaps because outcome is often influenced by subtle attitudes, beliefs and quality of life considerations. Management involves both education and a variety of interventions that range from simple single strategies to complex multimodal approaches in which the patient's role may vary from being a passive participant of professional supervision to complete autonomy and self-care.

ECT and tardive dyskinesia

Three cases of elderly depressed patients with symptoms of tardive dyskinesia (TD) subsequently treated with electroconvulsive therapy (ECT) are presented. These cases are discussed in relation to several cases reported in the literature of ECT and TD. The possibility of improvement in symptoms of TD in certain patients is discussed.

Case review and quantity of outpatient care

Case review for patients belonging to a health maintenance organization was implemented in a hospital-based, multidisciplinary, outpatient clinic after the influx of 28,000 Medicaid enrollees. One-year follow-up of 138 patients with prepaid mental health insurance and 283 patients with fee-for-service mental health insurance revealed an annual mean of 6.1 treatment sessions; 78% completed treatment within eight sessions. The modal treatment was a single visit. Prepaid and fee-for-service patients did not differ in amount of care, although significant differences were found for insurance subgroups. These preliminary results suggest that case review has little effect on quantity of care.

The activated patient: dogma, dream, or desideratum?

In this paper we critically review the active patient concept and place it in a broader social and historical context. We argue that as a reflection of core, Western European values, the active patient concept has not been adequately scrutinized. Very little research has been done that explicitly tests the claims that have been advanced on behalf of this ideal model of the clinician-patient relationship. The research that is available is far from definitive and does not support many of the assertions made by advocates of this approach to patienthood. We urge investigators to substitute theory driven research programs for those motivated by advocacy of a particular ideological stance.

Behavioral medicine programs in teaching hospitals

Behavioral medicine is a relatively new interdisciplinary field which combines biomedical and behavioral science knowledge, and applies them to prevention, diagnosis, treatment and rehabilitation. Behavioral medicine programs provide a valuable service to patients with chronic illness, psychosomatic or functional disorders, treatment noncompliance, and behavioral risk factors. Behavioral medicine faculty are also active in teaching and research on patient behavior, interviewing skills, health promotion and counseling, and management of chronic illnesses. However, the survival of behavioral medicine programs in teaching hospitals depends on their economic viability and academic status. Positive action is needed to ensure their continued growth and development.

Role adoption in residency training

Two hundred residents in training in Wisconsin during 1982 responded to a survey that assessed attitudes, stressors, and coping strategies in each of three areas: work environment, role adoption, and personal life. Results indicate that successful role adoption (making difficult decisions, displaying leadership, dealing with uncertainty, being personally responsible for patients' care) is the primary task of residency, balanced by increasing stress in maintaining social support systems in family and peer groups. Coping strategies are directed at promoting role adoption and preserving personal ties. Work factors that accentuate the tension between these two aspects create the most distress. The degree to which role adoption is accomplished, the stress imposed, and coping strategies employed differed significantly with gender, specialty, and program type.

Chronic pain management

In the past ten years developments in social psychology, neurochemistry, learning theory, and psychophysiology have expanded the concept of chronic pain into a biopsychosocial model, in which pain is viewed as a form of abnormal illness behavior influenced by a wide range of biological, social, and psychological factors. Using the literature on chronic pain, the authors discuss the evolution of the chronic pain concept into the multidisciplinary multimodal approach used by pain clinics today, and the factors identified in the literature that influence a patient's perception of pain. Finally, based on their experiences in setting up a pain clinic and on the literature on leading pain management programs, they discuss in detail the evaluation, treatment, and management strategies of a comprehensive chronic pain management program.

Drug interactions in psychopharmacology

The mechanisms underlying psychotropic drug interactions include alterations in gastrointestinal absorption, protein-binding, specific and nonspecific metabolic degradation, receptor interactions, and renal clearance. The risk of interactions can be minimized by detailed drug history-taking, use of rapid reference sources, patient education, and physician behaviors that include serious attention to somatic complaints, identification of "at risk" situations, and rational prescribing habits.

Benzodiazepine use and the biopsychosocial model

Longstanding concern about possible misuse of the physician's unique prerogative to prescribe sedative drugs that control behavior has been accentuated by the increasing use of benzodiazepines since 1960. The appropriateness of their use in solving psychosocial predicaments is increasingly questioned because their availability has coincided with social movements toward personal autonomy and scientific doubts about the adequacy of a biomedical model in health care. Recent information about patients, physicians' prescribing habits, and drugs leads to an exploration of the existing alternatives. Adoption of a biopsychosocial model could result in lowered drug use with increased levels of public and professional satisfaction.