Predictors of Unmet Dental Health Needs in US Adults in 2018: A Cross-Sectional Analysis.

OBJECTIVE: To identify predictors of unmet dental needs for adults 18 y of age or older in the United States. METHOD: Using the Aday and Andersen framework and data from the 2018 Behavioral Risk Factor Surveillance System (BRFSS), we ran logistic regression to estimate predictors for adults of not having a dental visit within 5 y and having lost any teeth using a national sample of 155,060 survey respondents. RESULTS: Results showed that predisposing factors (age, race/ethnicity, gender, and educational attainment) and enabling factors (income and health insurance status) are important predictors for losing teeth due to decay or gum disease. Men, the elderly, and less educated and low-income residents were less likely to have seen a dentist within the past 5 y and more likely to have lost their permanent teeth. Compared to non-Hispanic White adults, Hispanics adults were more likely to have had a dental visit within the past 5 y. Unmet dental needs varied across states. People living in states with extensive Medicaid dental care benefit coverage were less likely to lose their teeth and more likely to have had a dental visit within the past 5 y. CONCLUSION: Efforts to improve oral health should address unmet dental needs of men and adults with low socioeconomic status. Studying the variation between state oral health care programs could further our understanding of how public policy can improve population oral health. KNOWLEDGE TRANSFER STATEMENT: Men, non-Hispanic Blacks, mixed and other race minorities, and low socioeconomic status adults are most at risk of unmet dental needs. States can address these needs by expanding Medicaid coverage for adults.

Race, Medical Mistrust, and Segregation in Primary Care as Usual Source of Care: Findings from the Exploring Health Disparities in Integrated Communities Study.

Compared to White Americans, African-Americans are less likely to use primary care (PC) as their usual source of care. This is generally attributed to race differences in socioeconomic status and in access to primary care services. Little is known about the relationship between race differences in medical mistrust and the usual source of care disparity. Using data from the Exploring Health Disparities in Integrated Communities (EHDIC) study, we examined the role of medical mistrust in choosing usual source of care in 1408 black and white adults who were exposed to the same healthcare facilities and low-income racially integrated community. Multinomial logistic regression models were estimated to examine the relationship between race, medical mistrust, and usual source of care. After adjusting for demographic and health-related factors, African-Americans were more likely than whites to use the emergency department (ED) (relative risk ratio [RRR] = 1.43 (95 % confidence interval (CI) [1.06-1.94])) and hospital outpatient department (RRR1.50 (95 %CI [1.10-2.05])) versus primary care as a usual source of care. When medical mistrust was added to the model, the gap between African-Americans' and whites' risk of using the ED versus primary care as a usual source of care closed (RRR = 1.29; 95 % CI [0.91-1.83]). However, race differences in the use of the hospital outpatient department remained even after accounting for medical mistrust (RRR = 1.67; 95 % CI [1.16-2.40]). Accounting for medical mistrust eliminated the ED-as-usual-source of care disparity. This study highlights the importance of medical mistrust as an intervention point for decreasing ED use as a usual source of care by low-income, urban African-Americans.

Health insurance and chronic conditions in low-income urban whites.

Little is known about how health insurance contributes to the prevalence of chronic disease in the overlooked population of low-income urban whites. This study uses cross-sectional data on 491 low-income urban non-elderly non-Hispanic whites from the Exploring Health Disparities in Integrated Communities-Southwest Baltimore (EHDIC-SWB) study to examine the relationship between insurance status and chronic conditions (defined as participant report of ever being told by a doctor they had hypertension, diabetes, stroke, heart attack, anxiety or depression, asthma or emphysema, or cancer). In this sample, 45.8 % were uninsured, 28.3 % were publicly insured, and 25.9 % had private insurance. Insured participants had similar odds of having any chronic condition (odds ratios (OR) 1.06; 95 % confidence intervals (CI) 0.70-1.62) compared to uninsured participants. However, those who had public insurance had a higher odds of reporting any chronic condition compared to the privately insured (OR 2.29; 95 % CI 1.21-4.35). In low-income urban areas, the health of whites is not often considered. However, this is a significant population whose reported prevalence of chronic conditions has implications for the Medicaid expansion and the implementation of health insurance exchanges.

Acid-shock of Campylobacter jejuni induces flagellar gene expression and host cell invasion.

The bacterial pathogen Campylobacter jejuni is the leading cause of foodborne gastroenteritis in the developed world, with the organism being transmitted by ingestion of contaminated and undercooked poultry. Exposure to acid is an inevitable stressor for C. jejuni during gastric passage, yet the effect of low pH on C. jejuni virulence is still poorly understood. Here, we investigate the effect of acid-shock on C. jejuni viability, gene expression and host-cell invasion. C. jejuni strain NCTC 11168 survived acid exposure at pH 3.5 and above for up to 30 min without a drop in viability, and this exposure induced the expression of flagellar genes transcribed from σ(54)-dependent promoters. Furthermore, acid-shock resulted in increased C. jejuni invasion of m-ICcl2 mouse small intestine crypt cells grown on transwells, but not when the cells were grown on flat-bottomed wells. This suggests that C. jejuni might be invading intestinal epithelial cells at the basolateral side, possibly after paracellular passage. We hypothesize that acid-shock prior to intestinal entry may serve as a signal that primes C. jejuni to express its virulence gene repertoire including flagellar motility genes, but this requires further study in the context of an appropriate colonization or disease model.

Genomics of thermophilic campylobacter species.

The thermophilic Campylobacter species C. jejuni and C. coli are important human pathogens, which are major causes of bacterial gastroenteritis. The recent progress in genomics techniques has allowed for a rapid increase in our knowledge of the molecular biology of Campylobacter species, but needs to be matched by concurrent increases in our understanding of the unique biology of these organisms. Campylobacter species display significant levels of genomic variation via natural transformation, phase variation, plasmid transfer and infection with bacteriophages, and this poses a continuous challenge for studies on pathogenesis, physiology, epidemiology and evolution of Campylobacter. In this chapter we will review the current state of the art of the genomics of thermophilic Campylobacter species, and opportunities where genomics can further contribute to our understanding of the biology of these successful human pathogens.

Phage display combinatorial libraries of short peptides: ligand selection for protein purification.

A library of heptapeptides displayed on the surface of filamentous phage M13 was evaluated as a potential source of affinity ligands for the purification of Rhizomucor miehei lipase. Two independent selection (biopanning) protocols were employed: the enzyme was either physically adsorbed on polystyrene or chemically immobilized on small magnetic beads. From screening with the polystyrene-adsorbed lipase it was found that there was a rapid enrichment of the library with "doublet" clones i.e. the phage species which carried two consecutive sequences of heptapeptides, whilst no such clones were observed from the screening using lipase attached to magnetic beads. The binding of the best clones to the enzyme was unambiguously confirmed by ELISA. However the synthetic heptapeptide of identical sequence to the best "monomeric" clone did not act as a satisfactory affinity ligand after immobilization on Sepharose. This indicated that the interaction with lipase was due to both the heptapeptide and the presence of a part of the phage coat protein. This conclusion was further verified by immobilizing the whole phage on the surface of magnetic beads and using the resulting conjugate as an affinity adsorbent. The scope of application of this methodology and the possibility of preparing phage-based affinity materials are briefly discussed.

Enantioselectivity of recombinant Rhizomucor miehei lipase in the ring opening of oxazolin-5(4H)-ones.

Enantioselectivity of enzyme catalysis is often rationalized via active site models. These models are constructed on the basis of comparing the enantiomeric excess of product observed in a series of reactions which are conducted with a range of homologous substrates, typically carrying various side chain substitutions. Surprisingly the practical application of these simple but informative 'pocket size' models has been rarely tested in genetic engineering experiments. In this paper we report the construction, purification and enantioselectivity of two recombinant Rhizomucor miehei lipases which were designed to check the validity of such a model in reactions of ring opening of oxazolin-5(4H)-ones.

Alteration of lipase chain length specificity in the hydrolysis of esters by random mutagenesis.

The feasibility of altering the chain length specificity of industrially important Rhizomucor miehei lipase was investigated by randomly mutating Phe94 in the protein groove which is responsible for accommodating the acyl chain of the substrate. The recombinant lipase was initially expressed in E. coli. Individual colonies were selected, grown, and the DNA sequence of the lipase gene determined. Fourteen of the 19 possible mutants were identified and each of these was transformed into Pichia pastoris which expresses the enzyme extracellularly. The yeast was grown and the supernatants assessed in several assays with long and short chain substrates. Based on this preliminary screen, one mutant, Phe94Gly, was selected and purified to homogeneity for further analysis. It was found that the substitution of phenylalanine 94 with glycine led to an enzyme which was about six times less active against resorufin ester but displayed 3-4 times higher activity with short chain substrates such as butyric acid esters. The observed alteration to the enzyme specificity was rationalised using the available 3D structure of the lipase.

Are urban safety-net hospitals losing low-risk Medicaid maternity patients?

OBJECTIVE: To examine data on Medicaid and self-pay/charity maternity cases to address four questions: (1) Did safety-net hospitals' share of Medicaid patients decline while their shares of self-pay/charity-care patients increased from 1991 to 1994? (2) Did Medicaid patients' propensity to use safety-net hospitals decline during 1991-94? (3) Did self-pay/charity patients' propensity to use safety-net hospitals increase during 1991-94? (4) Did the change in Medicaid patients' use of safety-net hospitals differ for low- and high-risk patients? STUDY DESIGN: We use hospital discharge data to estimate logistic regression models of hospital choice for low-risk and high-risk Medicaid and self-pay/charity maternity patients for 25 metropolitan statistical areas (MSAs) in five states for the years 1991 and 1994. We define low-risk patients as discharges without comorbidities and high-risk patients as discharges with comorbidities that may substantially increase hospital costs, length of stay, or morbidity. The five states are California, Florida, Massachusetts, New Jersey, and New York. The MSAs in the analysis are those with at least one safety-net hospital and a population of 500,000 or more. This study also uses data from the 1990 Census and AHA Annual Survey of Hospitals. The regression analysis estimates the change between 1991 and 1994 in the relative odds of a Medicaid or self-pay/charity patient using a safety-net hospital. We explore whether this change in the relative odds is related to the risk status of the patient. PRINCIPAL FINDINGS: The findings suggest that competition for Medicaid patients increased from 1991 to 1994. Over time, safety-net hospitals lost low-risk maternity Medicaid patients while services to high-risk maternity Medicaid patients and self-pay/charity maternity patients remained concentrated in safety-net hospitals. IMPLICATIONS FOR POLICY: Safety-net hospitals use Medicaid patient revenues and public subsidies that are based on Medicaid patient volumes to subsidize care for uninsured and underinsured patients. If safety-net hospitals continue to lose their low-risk Medicaid patients, their ability to finance care for the medically indigent will be impaired. Increased hospital competition may improve access to hospital care for low-risk Medicaid patients, but policymakers should be cognizant of the potential reduction in access to hospital care for uninsured and underinsured patients. Public policymakers should ensure that safety-net hospitals have sufficient financial resources to care for these patients by subsidizing their care directly.

Racial and ethnic differences in preventable hospitalizations across 10 states.

Using discharge data from 10 states, this study estimates the effects of race and ethnicity on the likelihood of being hospitalized for a preventable condition--an indicator of limited access to primary care. The authors find that African Americans and Hispanics are more likely to be hospitalized for preventable conditions. In particular, controlling for differences in patients' health care needs, socioeconomic status, insurance coverage, and the availability of primary care, Hispanic children, working-age African American adults, and elderly patients from both minority groups are at greater risk than are similar white patients.

Physicians' responses to Medicare fee schedule reductions.

BACKGROUND: Relatively little empirical research has addressed physicians' responses to fee changes under the Medicare Fee Schedule. OBJECTIVES: We analyzed Medicare claims data for ophthalmologists and orthopedic surgeons for the years 1991 through 1994 to evaluate the relative importance of profit-maximizing and target-income theories in determining physicians' supply responses to specific Medicare fee reductions. RESEARCH DESIGN: This study was designed to estimate the impact of fee reductions for cataract extractions and major joint repair/replacement procedures through pooled cross-section time series data. RESULTS: The supply function for cataract extractions has both strong own-price and cross-price effects, as well as a highly significant negative income effect. Yet, the magnitude of the income effect is small; thus, the substitution effect dominates the income effect. Similarly, in the supply functions for joint procedures, the own price has the expected positive sign, implying that as the fee declines, orthopedic surgeons will perform fewer joint surgeries. However, the cross-price variable has the correct sign only if treated as exogenous, and the variables measuring the income effect have the wrong sign, although their magnitude is small. CONCLUSIONS: These results suggest that the Medicare Fee Schedule does have the potential to influence physicians' supply decisions, but these effects may vary by specialty and service.

Purification, molecular cloning, and expression of the gene encoding fatty acid 13-hydroperoxide lyase from guava fruit (Psidium guajava).

Guava fruit was identified as a particularly rich source of 13-hydroperoxide lyase activity. The enzyme proved stable to chromatographic procedures and was purified to homogeneity. Based on gel filtration and gel electrophoresis, the native enzyme appears to be a homotetramer with subunits of 55 kD. Starting with primers based on the peptide sequence, the enzyme was cloned by polymerase chain reaction with 3' and 5' rapid amplification of cDNA ends. The sequence shows approximately 60-70% identity to known 13-hydroperoxide lyases and is classified in cytochrome P450 74B subfamily as CYP74B5. The cDNA was expressed in Escherichia coli (BL21 cells), with optimal enzyme activity obtained in the absence of isopropyl-beta-D-thiogalactopyranoside and delta-aminolevulinic acid. The expressed enzyme metabolized 13(S)-hydroperoxylinolenic acid over 10-fold faster than 13(S)-hydroperoxylinoleic acid and the 9-hydroperoxides of linoleic and linolenic acids. 13(S)-Hydroperoxylinolenic acid was converted to 12-oxododec-9(Z)-enoic acid and 3(Z)-hexenal, as identified by gas chromatography-mass spectrometry. The turnover number with this substrate, with enzyme concentration estimated from the Soret absorbance, was approximately 2000/s, comparable to values reported for the related allene oxide synthases. Distinctive features of the guava 13-hydroperoxide lyase and related cytochrome P450 are discussed.

Impact of quality of life on patient expectations regarding phase I clinical trials.

PURPOSE: Quality of life (QOL) is increasingly recognized as a critical cancer-treatment outcome measure, but little is known about the impact of QOL on the patient decision-making process. A pilot study was conducted in an effort to (1) measure the expectations of patients, physicians, and research nurses regarding the potential benefits and toxicities from experimental and standard therapies, and (2) determine the relationship of QOL to patient perceptions regarding treatment options. METHODS: Thirty cancer patients enrolling in phase I clinical trials, their physicians, and their research nurses were administered questionnaires that assessed demographics, QOL, and treatment expectations. RESULTS: Compared with their physicians, patients overestimated potential benefits and toxicities from experimental therapy (mean expected benefit, 59.8% v 23.8%, P <.01; mean expected toxicity, 29.8% v 16.0%, P <.01). Patients estimated a greater potential for benefit (59.8% v 36.8%, P <.01) and less potential for toxicity (29.8% v 45.6%, P =.01) for experimental therapy, compared with standard therapy. Short Form-36 general health perception correlated with patient perception of potential benefit from experimental therapy (r =.48, P =.01). CONCLUSION: Participants in phase I clinical trial have high expectations regarding the success of experimental therapy and discount potential toxicity. Patient QOL may affect the expectation of benefit from experimental therapy and, ultimately, treatment choice. Understanding the interactions between QOL and patient expectations may guide the development of improved strategies to present appropriate information to patients considering early-phase clinical trials.

Population characteristics of markets of safety-net and non-safety-net hospitals.

RESEARCH OBJECTIVES: To compare and contrast the markets of urban safety-net (USN) hospitals with the markets of other urban hospitals. STUDY DESIGN: To develop profiles of the actual inpatient markets of hospitals, we linked 1994 patient-level information from hospital discharge abstracts from nine states with 1990 data at the ZIP code level from the US Census Bureau. Each hospital's market was characterized by its racial and ethnic composition, median household income, poverty rate, and educational attainment. Measures of hospital competition were also calculated for each hospital. The analysis compared the market profiles of USN hospitals to those of other urban hospitals. We also compared the level of hospital competition and financial status of USN and other urban hospitals. PRINCIPAL FINDINGS: The markets of USN hospitals had higher proportions of racial and ethnic minorities and non-English-speaking residents. Adults residing in markets of USN hospitals were less educated. Families living in markets of USN hospitals had lower incomes and were more likely to be living at or below the federal poverty level. USN hospitals and other urban hospitals faced similar levels of competition and had similar margins. However, USN hospitals were more dependent on Medicare disproportionate share payments and on state and local government subsidies to remain solvent. CONCLUSION: USN hospitals disproportionately serve vulnerable minority and low-income communities that otherwise face financial and cultural barriers to health care. USN hospitals are dependent on the public subsidies they receive from federal, state, and local governments. Public policies and market pressures that affect the viability of USN hospitals place the access to care by vulnerable populations at risk. Public policy that jeopardizes public subsidies places in peril the financial health of these institutions. As Medicare and Medicaid managed care grow, USN hospitals may lose these patient revenues and public subsidies based on their Medicaid and Medicare patient volumes. The loss of these funds would hinder the ability of USN hospitals to finance uncompensated care for uninsured and underinsured patients.

Treatment choices by seriously ill patients: the Health Stock Risk Adjustment model.

Anecdotal evidence suggests that patients who have life-threatening conditions often choose to undergo high-cost, high-risk treatments for them. This kind of risk-seeking behavior seems irrational because most patients are risk-averse. The Health Stock Risk Adjustment (HSRA) model seeks to explain this phenomenon. The model is based on the concept of relative health stock--the ratio of patients' expected quality-adjusted life years (QALYs) after a diagnosis to their expected QALYs before the diagnosis. The model predicts risk-averse patients will behave in a risk-seeking manner as their relative health stocks deteriorate. The HSRA model can help physicians better understand why some seriously ill patients seek high-risk treatments while others elect to forgo treatment. State legislatures and insurers are attempting to appropriately design insurance benefits for patients with life-threatening conditions. The HSRA model can help predict which patients will most likely take advantage of these benefits.

The impact of HMO penetration on the rate of hospital cost inflation, 1985-1993.

This paper provides evidence that growth in health maintenance organization (HMO) enrollment slows hospital cost inflation. During the period 1985-1993, hospitals in areas with high rates of HMO penetration and growth had a slower rate of growth in expenses (8.3%) than hospitals in low penetration areas (11.2%). From 1992-1993, HMO growth lowered the rate of hospital cost inflation by .34 to 3.40 percentage points, depending on the base-year level and the annual change in HMO penetration. Declines in Medicare Prospective Payment System (PPS) margins also lowered hospital cost inflation; over the time period, annual hospital cost inflation was reduced by .38 percentage points. The estimates imply that the cumulative effect of HMO growth on hospital costs has been a $56.2 billion reduction (in 1993 dollars).

The impact of health maintenance organization penetration on the use of hospitals that serve minority communities.

OBJECTIVES: Health maintenance organization (HMO) penetration has made hospital markets more price competitive. Hospitals in minority communities may be at a competitive disadvantage because they serve patients who are, on average, sicker and more likely to be uninsured or underinsured. This study estimated the impact of HMO penetration on the use of hospitals in minority communities during 1987 to 1992. METHODS: Using a sample of 1,413 short-term general hospitals from the 85 largest metropolitan statistical areas, the determinants of hospitals' patient volumes were estimated. Hospitals located in predominately nonwhite neighborhoods were designated minority hospitals, and other hospitals were designated nonminority hospitals. Using regression analysis, the impact of HMO penetration and concentration on hospitals' patient volumes were estimated. By interacting the HMO penetration and concentration variables with a minority hospital indicator variable, HMOs' impact on minority hospitals was calculated. RESULTS: Health maintenance organization penetration was correlated with lower patient volumes in minority hospitals and higher patient volumes in nonminority hospitals. Competition in HMO markets was correlated with lower patient volumes for all hospitals. This effect was stronger for minority hospitals. CONCLUSIONS: These findings suggest that minority hospitals may be at risk of losing patients as HMO penetration increases.

Altruism or moral hazard: the impact of hospital uncompensated care pools.

Empirical evidence from New Jersey supports theories of hospitals altruism. From 1987 to 1992, New Jersey reimbursed hospitals for uncompensated care through the Uncompensated Care Trust Fund. The Trust Fund reduced the shadow price of charity care, inducing hospitals to increase their provision of uncompensated care. Hospitals increased inpatient uncompensated care by an average of 14.8% and statewide uncompensated care increased by $360 million during 1987-1990. Empirical evidence suggests that the state effectively addressed the moral hazard problem created by the Trust Fund by auditing uncompensated care and regulating hospital collection procedures.