Interconception care during well-child visits by family physicians in the United States: A cross-sectional study

Background

Interconception care (ICC) by family physicians during well-child visits (WCVs) has been broadly advocated in principle but has not been widely implemented. We aimed to investigate ICC at WCVs by family physicians at our facility, focusing on four maternal risk factors, including maternal tobacco use, maternal depression, contraception, and folic acid supplementation.

Methods

Mothers who visited WCVs with children up to the age of 24 months at our university-affiliated clinic were screened for the four maternal risks. Brief interventions were provided to mothers with positive screening results. We investigated mothers at WCVs from December 1, 2020, to November 30, 2022. We performed descriptive and binary logistic regression analyses to determine the maternal demographic factors associated with positive screenings.

Results

Of 1143 WCVs, 205 mothers were evaluated. Screening was positive in the following rates: tobacco use 5.9%, depression 11.5%, contraception 73.6%, and folic acid supplementation 40.5%. Single marital status was associated with positive screening for smoking (odds ratio [OR] 8.689, p = 0.016) and maternal depression (OR 3.470, p = 0.035). Maternal education level lower than a high school diploma was associated with positive screening for folic acid intake (OR 4.975, p = 0.004).

Conclusions

ICC conducted during WCVs by family physicians offers valuable opportunities to identify maternal risk factors and address modifiable factors that can influence future birth outcomes. Single marital status and educational level less than a high school diploma were more potent risk factors for maternal behavior in ICC. More research is needed to assess the outcomes of the interventions.

Critical values of learning to speak English for Japanese clinicians

We suggest three reasons why Japanese clinicians should learn to speak English: international academic interaction, gaining experience abroad, and having another skill in the rapidly changing world during the COVID-19 pandemic. Not only reading and writing English but also speaking the language is inevitable for Japanese clinicians. Although speaking English is not easy owing to the disparity between English and Japanese, verbal English fluency adds tremendous value to academic development.

Pilot evaluation of a biopsychosocial integrated standardized patient examination in a family medicine clerkship

OBJECTIVE

A new biopsychosocial Integrated Standardized Patient Examination (ISPE) was implemented to assess communication skills for medical students participating in a family medicine clerkship.

METHOD

Mixed method, multi-level evaluation.

RESULTS

Pilot ISPE scores were significantly higher than previous Objective Structured Clinical Examination (OSCE) (p < .01). Family Physician and Social/Behavioral Scientist rater scores were correlated (p < .001), and Cronbach's alpha statistics were acceptable (FM: alpha = .837; BH: alpha = .768). Preceptor scores on "relations with professionals" (beta = .694, p = .008) significantly predicted ISPE scores, but other clerkship assignment grades were inversely associated with ISPE. Qualitative focus group themes included lack of readiness, divergence in beliefs on scope of physician practice, and focus on grade.

CONCLUSIONS

This pilot project describes the process and demonstrates the possibility of implementing a complex standardized patient case to assess students' management of complicated primary care patients with medical, psychological, and social issues.

Intrapartum fetal monitoring

Continuous electronic fetal monitoring was developed in the 1960s to assist in the diagnosis of fetal hypoxia during labor. Continuous electronic fetal monitoring has been shown to reduce the incidence of neonatal seizures, but there has been no beneficial effect in decreasing cerebral palsy or neonatal Continuous electronic fetal monitoring was developed in the 1960s to assist in the diagnosis of fetal hypoxia during labor. Continuous electronic fetal monitoring has been shown to reduce the incidence of neonatal seizures, but there has been no beneficial effect in decreasing cerebral palsy or neonatal mortality. Intraobserver variability may play a major role in its interpretation. To provide a systematic approach to interpreting the electronic fetal monitor tracing, the National Institute of Child Health and Human Development convened a workshop in 2008 to revise the accepted definitions for electronic fetal monitor tracing. The key elements include assessment of baseline heart rate, presence or absence of variability, and interpretation of periodic changes. The workshop introduced a new classification scheme for decision making with regard to tracings. This system can be used in conjunction with the Advanced Life Support in Obstetrics course mnemonic, DR C BRAVADO, to assist in the systematic interpretation of fetal monitoring. DR C BRAVADO incorporates maternal and fetal risk factors (DR = determine risk), contractions (C), the fetal monitor strip (BRA = baseline rate, V = variability, A = accelerations, and D = decelerations), and interpretation (O = overall assessment).

Antihistamines and/or decongestants for otitis media with effusion (OME) in children

BACKGROUND

Otitis media with effusion (OME) is common and may cause hearing loss with associated developmental delay. Treatment remains controversial. The effectiveness of antihistamines, decongestants and antihistamine/decongestant combinations in promoting the resolution of effusions has been assessed by randomized controlled trials.

OBJECTIVES

The objective of this review is to determine whether antihistamine, decongestant, or combination therapy is effective in treating children who present with OME.

SEARCH STRATEGY

The Cochrane Ear, Nose and Throat Disorders Group Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, Issue 1 2006), EMBASE (1974 to 2006), MEDLINE (1951 to 2006) and a gray literature database were searched using a search strategy created by an experienced medical librarian. The date of the last search was March 2006. Reference lists from included studies and relevant reviews were searched by hand; pharmaceutical manufacturers of antihistamines and decongestants and first authors of included studies were contacted to identify other potentially relevant studies.

SELECTION CRITERIA

Randomized controlled trials (RCTs) using antihistamines, decongestants or antihistamine/decongestant combinations as treatment for OME in children were selected. We excluded trials that randomized on the basis of acute otitis media (AOM) even though OME was also studied in follow up.

DATA COLLECTION AND ANALYSIS

Data were extracted from the published reports by two authors independently using standardized data extraction forms and methods. The methodological quality of the included studies was independently assessed by two authors. Dichotomous results were expressed as a relative risk with 95% confidence intervals using a fixed-effect model when homogeneous and a random-effects model when heterogeneous. Nearly all outcomes analysed were homogeneous. Continuous results were discussed qualitatively. Statistical analysis was conducted using RevMan software.

MAIN RESULTS

No statistical or clinical benefit was found for any of the interventions or outcomes studied. However, treated study subjects experienced 11% more side effects than untreated subjects (number needed to treat to harm = 9).

AUTHORS' CONCLUSIONS

Because the pooled data demonstrate no benefit and some harm from the use of antihistamines or decongestants alone or in combination in the management of OME, we recommend against their use.

Global hexachlorobenzene emissions

Information from a variety of sources has been assembled to give a global picture of hexachlorobenzene (HCB) emissions in the mid 1990s. No single overwhelming source of HCB was identified. The best estimates of global HCB emissions from different categories of sources are as follows: pesticides application - 6500 kg/yr; manufacturing - 9500 kg/yr; combustion - 7000 kg/yr, includes 500 kg from biomass burning. This adds up to total current HCB emissions of approximately 23,000 kg/yr with an estimated range 12,000-92,000 kg/yr. A substantial portion of HCB measured in the atmosphere is thought to come from volatilization of "old" HCB on the soil from past contamination along with unidentified sources. No information on potential sources in developing countries was available.

Rapid bioanalytical determination of dextromethorphan in canine plasma by dilute-and-shoot preparation combined with one minute per sample LC-MS/MS analysis to optimize formulations for drug delivery

The determination of dextromethorphan in canine plasma is used to demonstrate the high throughput bioanalytical approach of automated dilute-and-shoot (DAS) sample preparation followed by a 1 min isocratic liquid chromatography tandem mass spectrometry (LC-MS/MS) analysis. Dilute-and-shoot preparation is commonly used for the determination of drugs in several biological matrices such as urine and saliva, but is not typically used with plasma samples because the amount of protein present in plasma can lead to a variety of problems including column failure. As a result, plasma sample preparation usually removes protein by precipitation, extraction or filtration; however, the dilute-and-shoot approach solubilizes proteins throughout the chromatographic portion of the assay. The attributes of this approach are compared with a previously validated liquid/liquid extraction procedure for determination of dextromethorphan in plasma. Accuracy and precision of both methods are similar. The lower limit of quantitation (LLOQ) of the dilute-and-shoot approach is much higher at 2 ng/ml versus 5 pg/ml with the liquid/liquid extraction; however, the sample throughput of the preparation portion of the dilute-and-shoot approach is more than 50-fold greater. The ruggedness of the dilute-and-shoot method was thoroughly investigated because of the problems traditionally associated with the direct injection of diluted plasma onto an LC-MS/MS instrument. With the optimal conditions, greater than 1,000 injections of diluted plasma have been successfully performed on a single column in less than 19 h making this technique an excellent approach for the rapid preparation and high throughput of plasma samples containing drug levels in the ng/ml range or higher. Application of this methodology to measure the levels of dextromethorphan in canine plasma to evaluate drug delivery from various formulations is also presented.

Comparison of packed-column supercritical fluid chromatography--tandem mass spectrometry with liquid chromatography--tandem mass spectrometry for bioanalytical determination of (R)- and (S)-ketoprofen in human plasma following automated 96-well solid-phase extraction

The popularity of packed-column supercritical fluid, subcritical fluid, and enhanced fluidity liquid chromatographies (pcSFC) for enantiomeric separations has increased steadily over the past few years. The addition of a significant amount (typically 20-95%) of a viscosity lowering agent, such as carbon dioxide, to the mobile phase provides a number of advantages for chiral separations. For example, higher mobile-phase flow rates can often be attained without a concomitant loss in chromatographic efficiency since diffusion coefficients, and optimum velocities, are typically higher in pcSFC. Ultratrace enantioselective quantitation of drugs in biomatrixes is an ideal application for these chromatographic attributes. To demonstrate the utility of this approach, a pcSFC tandem mass spectrometry (pcSFC-MS/MS) method was compared to a LC-MS/MS method for quantitation of the (R)- and (S)-enantiomers of ketoprofen (kt), a potent nonsteroidal, anti-inflammatory drug, in human plasma. After preparation using automated solid-phase extraction in the 96-well format, kt enantiomers were separated on a Chirex 3005 analytical column using isocratic conditions. Validation data and study sample data from patients dosed with either orally or topically administered ketoprofen were generated using both pcSFC and LC as the chromatographic methods to compare and contrast these analytical approaches. Generally, most analytical attributes, including specificity, linearity, sensitivity, accuracy, precision, and ruggedness, for both of these methods were comparable with the exception that the pcSFC separation provided a roughly 3-fold reduction in analysis time. A 2.3-min pcSFC separation and a 6.5-min LC separation provided equivalent, near-baseline-resolved peaks, demonstrating a significant time savings for analysis of large batch pharmacokinetic samples using pcSFC.

Determination of (R)- and (S)-ketoprofen in human plasma by liquid chromatography/tandem mass spectrometry following automated solid-phase extraction in the 96-well format

A sensitive and selective method was developed for the determination of (R)-ketoprofen ((R)-kt) and (S)-ketoprofen ((S)-kt) in human plasma using chiral liquid chromatography/tandem mass spectrometry (LC/MS/MS). Plasma samples spiked with stable-isotope-labeled [(13)C(1), (2)H(3)]-(R and S)-ketoprofen, for use as the internal standards, were prepared for analysis using automated solid-phase extraction (SPE) in the 96-well microtiter format. The enantiomers were separated on an (R)-1-naphthylglycine and 3,5-dinitrobenzoic acid (Chirex 3005) 250x2.0 mm i.d. analytical column, equipped with a 30x2.0 mm i.d. guard column using isocratic mobile phase conditions. The (R)- and (S)-kt levels were quantifiable from 0.05 to 2500 ng ml(-1) by constructing two separate curves from calibration standards covering the same range. The first curve ranged from 0.05 to 100 and the second from 100 to 2500 ng ml(-1). A concentration of 0.05 ng ml(-1) of either enantiomer was easily detected using a 1 ml plasma sample volume. The average method accuracy, evaluated at four levels over an extended period, was better than +/-3% over the entire range. The precision for the same set of quality control samples ranged from 4.0 to 7.0 % RSD (n = 24). The method was applied to the evaluation of pharmacokinetic parameters in human plasma obtained from volunteers who received 25 mg of kt by peroral administration of Actron caplets or by topical administration of Oruvail gel.

Stability of alatrofloxacin mesylate in 5% dextrose injection and 0.45% sodium-chloride injecion

A high-performance liquid chromatographic assay method for the quantitation of alatrofloxacin in intravenous (IV) admixtures has been developed. The method is accurate and precise, with a percent relative standard deviation of 1.2% based on five injections. The method is stability indicating since the product of decomposition, trovafloxacin, did not interfere with the assay procedure. The IV admixtures of alatrofloxacin (1.88 mg/mL) in 5% dextrose and 0.45% sodium-chloride injections were stable for at least nine days when stored at room themperature. The pH values of the admixtures did not change and they remained clear throughout this study.

Design and assembly of an 8 tesla whole-body MR scanner

PURPOSE

The purpose of this report is to describe the design and construction of an 8 T/80 cm whole-body MRI system operating at 340 MHz.

METHOD

The 8 T/80 cm magnet was constructed from 414 km of niobium titanium superconducting wire. The winding of this wire on four aluminum formers resulted in a total inductance of 4,155 H. Gradient subsystems included either a body gradient or a head gradient along with a removable shim insert. The magnet and gradient subsystems were interfaced to two spectrometers. These provided the control of the gradient amplifiers and the two sets of four RF power amplifiers. The latter provide in excess of 8 kW of RF power from 10 to 140 MHz and 10 kW of RF power from 245 to 345 MHz. A dedicated computer-controlled patient table was designed and assembled. The entire system is located in a clinical setting, facilitating patient-based studies.

RESULTS

The 8 T/80 cm magnet was energized without complication and achieved persistent operation using 198.9 A of current, thereby storing 81.5 MJ of magnetic energy. Exceptional performance was observed for nearly all components both in isolation and when combined within the complete system.

CONCLUSION

An 8 T/80 cm MRI system has been assembled. The magnet subsystem is extremely stable and is characterized by good homogeneity and acceptable boil-off rates.

The impact of real wage and mortality fluctuations on fertility and nuptiality in precensus England

"This paper explores the responses of fertility and nuptiality to fluctuations in real wages and mortality that can be inferred from annual series of English historical data over the period 1542 to 1800. The paper begins with a review of the time series properties of the data and summarizes the long-term equilibrium relationships identified in previous work.... An investigation is made of the impact of shocks to real wages and mortality on demographic variables as measured by generalized impulse responses and persistence profiles."

Predisposing factors for individuals' Lyme disease prevention practices: Connecticut, Maine, and Montana

OBJECTIVES

This study examined factors that predispose individuals to protect against Lyme disease.

METHODS

Knowledge, attitude, and practice questions concerning Lyme disease prevention were included in the Behavioral Risk Factor Surveillance surveys in Connecticut, Maine, and Montana. A total of 4246 persons were interviewed.

RESULTS

Perceived risk of acquiring Lyme disease, knowing anyone with Lyme disease, knowledge about Lyme disease, and believing Lyme disease to be a common problem were significantly associated with prevention practices.

CONCLUSIONS

Predisposing factors differ substantially between states and appear related to disease incidence. Personal risk, knowing someone with Lyme disease, and cognizance about Lyme disease and acting on this information are consistent with social learning theories.

Stability of cefepime hydrochloride dextrose in 5% dextrose injection and 0.9% sodium chloride injection

The stability of cefepime hydrochloride in 5% dextrose injection and 0.9% sodium chloride injection was studied using a stability-indicating assay method developed in our laboratory. This method is precise and accurate, with a percent relative standard deviation of 0.7% based on five readings. The admixtures were stable for two days at 25 deg C and 23 days at 5 deg C. The pH values of the admixtures did not change throughout this study, and the colors had changed from a very light yellow to a light yellow. The manufacturer recommends an expiry date of 24 hours at 20 to 25 deg C and seven days at 2 to 8 deg C.

Stability of ceftriaxone sodium when mixed with metronidazole injection

The chemical stabilities of ceftriaxone sodium and metronidazole in a mixture have been studied using a stability-indicating, high-performance liquid chromatography (HPLC) assay method. The HPLC method is precise and accurate, with a percent relative standard deviation of 1.4 based on five readings. Metronidazole did not lose any potency for four days when stored at 25+/-1 deg C. Ceftriaxone sodium lost less than 6% ofpotency in three days at 25+/-1 deg C. The products of decomposition did not interfere with the assay procedure. They eluted before the ceftriaxone peak. The solution remained clear (light yellow) throughout the study period, and the pH value did not change. Ceftriaxone sodium and metronidazole, when mixed together, were stable for three days at 25+/-1 deg C.

Stability of ketorolac tromethamine in 5% dextrose injection and 0.9% sodium chloride injections

The stability of ketorolac tromethamine in 5% dextrose injection and 0.9% sodium cholride injection has been studied using a stability-indicating, high-performance liquid chromatography assay method developed in our laboratory. This method is precise and accurate, with a percent relative standard deviation of 0.85% based on five readings. The admixtures were stable for at least 50 days when stored at 5 deg C. At 25 deg C the 0.9% sodium chloride admixture was stable for at least 35 days, and in 5% dextrose injection for only seven days. After 14 days of storage at 25 deg C the pH value of the admixture in 5% dextrose injection had decreased from 6.6 to 4.3. The changes in pH values of all other admixtures were less than 0.55. This assay method can be used to quantify ketorolac tromethamine in injections and tablets.

Stability of cefmetazole sodium in 5% dextrose injection and 0.9% sodium chloride injection

The stability of cefmetazole sodium in 5% dextrose injection and 0.9% sodium choloride injection has been studied using a stability-indicating, high performance liquid chromatography (HPLC) assay method developed in our laboratory. This HPLC method is precise and accurate, with a percent relative standard deviation of 1.4 based on five readings. The admixtures were stable for two days at 25 deg C and for 28 days at 5 deg C, and they remained clear throughout the study period. The pH values decreased from 4.7 to 4.0 in 0.9% sodium chloride injection and from 4.8 to 4.2 in 5% dextrose injection. The expiry date of seven days at 5 deg C recommended by the manufacturer appears to be conservative from a chemical-stability standpoint.

Serodiagnosis of Lyme disease: accuracy of a two-step approach using a flagella-based ELISA and immunoblotting

An ELISA containing a purified flagellar antigen from Borrelia burgdorferi (FLA-ELISA) was evaluated. The FLA-ELISA, detecting IgM and IgG together, did not have adequate specificity by itself. Good accuracy was obtained, however, when the FLA-ELISA was the first step in a two-step protocol that used immunoblotting as a conditional second test. Samples that scored positive or equivocal by the FLA-ELISA were evaluated with separate IgM and IgG immunoblots. The sensitivity of the two-step process for patients with erythema migrans or with later manifestations of Lyme disease was 64% and 100%, respectively. The specificity for health blood donors was 100% and was 90% for the aggregate of all persons with illness that may cause serologic cross-reactivity (98% if the samples from relapsing fever patients were excluded). Test precision was 96% overall, 99% for Lyme disease case serum samples, 100% for specimens from blood donors, and 88% for samples from persons with other illness.

Cytokine responses to dengue infection among Puerto Rican patients

Recently, a strong correlation between high concentration of tumor necrosis factor (TNF alpha) in blood and severity of dengue hemorrhagic fever/dengue shock syndrome has been reported from Asia and the Pacific. We wished to determine if a similar relationship could be found in dengue patients in the Americas where adult patients with severe syndromes have been observed more frequently than in Asia where severe cases have been observed mostly among children. The concentrations of interleukin-1 (IL-1 beta) in hospitalized adult groups were significantly lower than that in outpatient adults. In contrast, the levels of interleukin 6 (IL-6) were significantly higher in hospitalized adults and children than in the corresponding outpatients. Levels of TNF alpha were higher in hospitalized children than in outpatient children or hospitalized adults. There was no significant difference in the levels of these three cytokines among hospitalized patients with or without hemorrhagic manifestations. Thus, an elevated IL-6 level was positively associated with severity of dengue infection in both children and adults, but IL-1 beta level was negatively associated with severity in adults.

Diagnosis and treatment of infectious mononucleosis

Infectious mononucleosis is caused by the Epstein-Barr virus (EBV) and most commonly affects young adults from 15 to 35 years of age. The diagnosis is made by accurate assessment of clinical, hematologic and serologic manifestations of the illness. Manifestations include the classic triad of fever, pharyngitis and cervical lymphadenopathy; lymphocytosis with a predominance of atypical lymphocytes; a positive heterophil (Monospot) antibody test; and in some cases, serologic evidence of EBV-specific antibodies produced against antigens related to the virus. The most valuable serologic finding is the presence of IgM antibody to EBV viral capsid antigen, which is found during acute primary EBV infection. Infectious mononucleosis is considered a self-limited illness, but it may result in serious complications involving the pulmonary, ophthalmologic, neurologic and hematologic systems. Treatment is focused on managing the symptoms, unless more severe disease involving other organ systems occurs. The most common potentially fatal complication is splenic rupture.

Eastern equine encephalitis (EEE): a description of the 1989 outbreak, recent epidemiologic trends, and the association of rainfall with EEE occurrence

An Eastern equine encephalitis (EEE) outbreak in 1989 led to nine human and 196 equine cases, chiefly in coastal Atlantic and Gulf Coast counties. In the past two decades, EEE age-specific incidence and mortality rates have declined compared with earlier years. Analysis of rainfall patterns in areas where human EEE cases occurred between 1983 and 1989 revealed an association between occurrence of human cases and excess rainfall. The association was stronger with data from local weather stations than from statewide rainfall averages and the predictive models were best when applied to northern states. The sensitivity and specificity of these measures varied, depending on the model used, but the positive predictive value was no better than 50%, regardless of the rainfall model applied.

Long-term demographic interactions in precensus England

"Modern time series methods are applied to the analysis of annual demographic data for England, 1541-1800. Evidence is found of non-stationarity in the series and of co-integration among the series. Building on economic models of historical demography, optimal inferential procedures are implemented to estimate the structural parameters of long-term equilibria among the variables. Evidence is found for a small, but significant, Malthusian 'preventive check' as well as interactions between fertility, mortality and nuptiality that are consistent with the predictions often made in demographic studies. Tentative experiments to detect the influence of environmental factors fail to reveal any significant impact on the estimates obtained."

National surveillance of Lyme disease, 1987-1988

In 1987 and 1988, 6876 Lyme disease cases from 43 states were reported to the Centers for Disease Control. The 4507 cases reported in 1988 was nearly double the case number reported in 1987, and ninefold the number reported in 1982, when a systematic system of national surveillance was established. The average annual incidence of reported Lyme disease in the United States in 1987-1988 was 1.4/100,000. New York led the nation in reported cases in 1988 with 57% of the cases reported nationally. Eight states, New York, New Jersey, Pennsylvania, Connecticut, Massachusetts, Rhode Island, Wisconsin, and Minnesota, reported 92% of the nation's cases. The state reporting the highest incidence rate in 1987-88 was Rhode Island, with 9.9 cases/100,000. Regionally, incidence rates were highest in Northeastern and Mid-Atlantic states, intermediate in North Central and Pacific states, lower in the Southeast, and lowest in the Great Plains and Mountains states. The seven remaining states in which Lyme disease has not been transmitted all lie west of the 100th meridian.

Epidemiological aspects of a St. Louis encephalitis outbreak in Harris County, Texas, 1986

An outbreak of St. Louis encephalitis (SLE) resulted in 28 cases of the disease in Harris County, Texas, in 1986. The cases occurred principally in Baytown, in eastern Harris County, but five cases were also recognized in Houston. The risk of illness increased sharply with age, and all five fatal cases were in persons greater than 55 y. Case-control methods were used for the first time to study factors associated with the risk of acquiring SLE. Risk was associated with residences poorly sealed against mosquitoes (non-air-conditioned residences and those with inadequate screens). The number of hours spent outdoors and in outdoor activities, except sitting immediately outside residences, were not associated with risk. Our observations suggest that exposure to vector mosquitoes may have occurred indoors. No host factors were significantly associated with risk of acquiring SLE, but more cases were cigarette smokers and had family histories of hypertension or cerebrovascular disease.

Epidemiologic aspects of a St. Louis encephalitis outbreak in Mesa County, Colorado

An epidemic of St. Louis encephalitis in 1985 in Mesa County, Colorado, led to 17 cases, including one fatality. Risk was associated with advanced age and residence in Grand Junction, the county's principal city. A trend was observed toward higher risk in females. However, increased risk in females was not associated with higher infection rates (increased exposure). Capture enzyme immunoassays detected specific immunoglobulin M (IgM) and immunoglobulin A after infection. A serosurvey of Grand Junction residents disclosed an infection rate of 4.0%, indicating that 1,123 epidemic St. Louis encephalitis infections may have occurred in the city. Evidence of previous St. Louis encephalitis virus infection was found in 11.2% of survey respondents who had neutralizing antibody to the virus without specific IgM. The prevalence of St. Louis encephalitis virus antibody was similar to rates observed in serosurveys undertaken 30 years earlier, indicating that the level of endemic St. Louis encephalitis transmission in the city had not changed appreciably in that interval.

Detection of St. Louis encephalitis virus antigen in mosquitoes by capture enzyme immunoassay

Surveillance methods that measure St. Louis encephalitis (SLE) virus activity in nature may provide forewarning of its epidemic occurrence in humans. An antigen capture enzyme immunoassay was developed to detect SLE virus in infected mosquitoes. The assay detected purified SLE viral antigen at a concentration of 62 pg/0.1 ml when antigen was incubated overnight; 250 pg/0.1 ml was detected in a single-day assay (antigen incubated for 3 h). The assay detected 67.9 and 70.8% of laboratory-prepared pools of infected mosquitoes after 3 h and overnight incubation, respectively. The sensitivity of the procedure was 90.5% in identifying pools with infectious titers greater than dex 3.0. The specificity of the assay was controlled by retesting positive pools preincubated with SLE virus and normal antibodies, which led to a diminution of signal in the pools containing viral antigen. The procedure was suitably specific in discriminating between SLE and related flaviviruses, detecting only high infectious doses of heterologous antigens.

Effects of ethanol on gastric epithelial cell phospholipid dynamics and cellular function

The lipid profile of isolated gastric superficial epithelial cells (SEC) was evaluated by proton nuclear magnetic resonance spectroscopy (1H-NMR). The most conspicuous resonance band in SEC spectra was due to the protons of +N(CH3)3 groups of phosphatidylcholine and, to a lesser degree, other phospholipid derivatives, on the basis of their chemical shift and addition of purified phospholipids. NMR of cell lysates and phospholipid extracts of SEC in deutero-chloroform provided further spectral resolution of these components. Phospholipase or ethanol treatments of SEC produced membrane disorganization reflected as increased peak intensity of the phospholipid signals. In addition, ethanol, in a dose-dependent manner, attenuated paranitrophenyl phosphatase activity, which correlated with inhibition of total and ouabain-sensitive 86Rubidium chloride uptake by SEC. This study suggests that NMR used in conjunction with other biochemical techniques can monitor SEC membrane structure-function relationships. NMR is a potentially powerful noninvasive probe to show changes in lipid membrane organization induced by low concentrations of ethanol (1%) and may indicate an early sign of "cytotoxicity" in intact SEC.

NMR studies of pig gastric microsomal H+,K+-ATPase and phospholipid dynamics. Effects of ethanol perturbation

The effects of ethanol on the gastric H+,K+-ATPase activity and the degree of mobility of various microsomal phospholipids were assessed using 31P and 1H NMR. This illuminated the role of lipid-protein association in the function of pig gastric microsomes. Treatment of gastric microsomes with 15% ethanol for 1 min at 37 degrees C inactivated the H+,K+-ATPase activity, which could largely be reconstituted by supplementation with phosphatidylcholine isolated from the gastric microsomes. Under similar conditions, the 1H NMR profile of the microsomal +N(CH3)3 choline moiety showed dramatic enhancement of peak intensity as well as a break point at 25 degrees C which was restored to the untreated control value after reconstitution. This break, together with the dramatic enhancement in the overall lipid profile, compared to the control and reconstituted microsomes, suggested a greater degree of freedom of movement of the microsomal lipids following ethanol perturbation. The data demonstrate the unique ability that a combined approach using 31P and 1H NMR holds as a noninvasive probe to study the structure-function relationship of biomembranes.

Dengue transmission in two Puerto Rican communities in 1982

Paired serologic, entomologic, and environmental surveys were performed in two Puerto Rican communities, Salinas and Manatí, in summer and fall 1982. Paired samples on 434 persons in Salinas and 324 persons in Manatí showed recent dengue infection rates of 35% and 26%, respectively. Ae. aegypti larval indices were higher in Salinas than in Manatí but were relatively high throughout both communities. Breteau indices in neighborhoods ranged from 43 to 172, and infection rates in the neighborhoods were 22% to 45%. With a multivariate technique, we analyzed possible associations of environmental variables with dengue incidence and prevalence of dengue antibody. Wood-constructed housing and low socioeconomic status were among the variables significantly associated with dengue incidence. Predictors of dengue antibody prevalence included socioeconomic level, tree height, shade, and window and door screens. Recent dengue infections clustered within the sampled members of households (P less than 0.05, binomial test). An estimated 35% of dengue infections were symptomatic, and no serious illnesses were reported. The potential for high dengue infection rates in Puerto Rico will continue unless substantial reductions in vector populations are achieved. Targeting dengue surveillance and vector control activities in areas with demonstrated environmental risk factors may limit transmission during future outbreaks.

Immunoglobulin M antibody capture enzyme-linked immunosorbent assay for diagnosis of St. Louis encephalitis

Sera from patients with St. Louis encephalitis were tested with an immunoglobulin M (IgM) antibody capture enzyme immunoassay (MAC ELISA). The assay used five reagents: antihuman IgM, test serum, sucrose-acetone-extracted mouse brain antigen, broadly cross-reactive flavivirus monoclonal antibody conjugated to alkaline phosphatase, and substrate (p-nitrophenyl phosphate). MAC ELISA endpoint titers correlated (r = 0.893) with the absorbance value of a 1:100 dilution of patient serum. Significant (fourfold or greater) changes in the endpoint titers between paired sera corresponded to a critical ratio (ratio of absorbance values at the 1:100 dilution) of greater than or equal to 1.3. IgM antibodies were detected in 71% of patients bled at 0 to 3 days after the onset of illness, in 99% bled at 4 to 21 days, and in 91% bled at 22 to 67 days. Thereafter, the IgM seropositivity rate declined; however, 29% of sera were still positive at 115 to 251 days after the onset of illness. MAC ELISA titers were significantly correlated with hemagglutination inhibition (r = 0.258) and neutralization (r = 0.711) titers. Because IgM antibodies appeared early and waned rapidly, a diagnosis was made on the basis of a decrease in titer more often by MAC ELISA than by hemagglutination inhibition, complement fixation, or neutralization tests. IgM antibodies generally showed a high degree of specificity; heterologous cross-reactions were, however, present in 4 of 14 sera examined. The MAC ELISA is useful for the rapid, early diagnosis of St. Louis encephalitis.

Acute hemorrhagic conjunctivitis in Puerto Rico, 1981-1982

In late 1981, the Western Hemisphere's pandemic of acute hemorrhagic conjunctivitis spread to Puerto Rico. Over 6,000 cases of conjunctivitis were reported to the Puerto Rico Department of Health from November 1981 to March 1982. Enterovirus 70 was isolated from one of 19 eye-swab specimens tested, and 10 of 13 (77%) individuals with acute hemorrhagic conjunctivitis had neutralizing antibody titers to enterovirus 70 of greater than or equal to 1:4. These data suggest that enterovirus 70 was the etiologic agent of the acute hemorrhagic conjunctivitis outbreak in Puerto Rico. In a study of a lower middle socioeconomic sector with relatively intense transmission, 152 of 670 (23%) persons reported illness consistent with acute hemorrhagic conjunctivitis. The highest attack rate was in the 5- to 14-year-old group (30%), and a disproportionate number of household index cases were in the predominantly school age group (5-19 years old). Twelve per cent (3/25) of asymptomatic household contacts of acute hemorrhagic conjunctivitis cases had sera with neutralizing antibody to enterovirus 70. Retrospective surveillance through ophthalmologists and neurologists identified one patient with a neurologic complication, a seventh nerve palsy temporally associated with recent enterovirus 70 infection. Household transmission was significantly associated with crowding and sharing of beds (p less than 0.05). This and other recent studies in Florida suggest that school age children play an important role in the transmission of acute hemorrhagic conjunctivitis. This study also suggests that asymptomatic enterovirus 70 infection is uncommon, and that in Puerto Rico, neurologic complications associated with acute hemorrhagic conjunctivitis were quite rare.

Symptomatic upper extremity venous thrombosis associated with permanent transvenous pacemaker electrodes

Symptomatic arm vein thrombosis secondary to permanent transvenous cardiac pacing electrodes is an uncommon occurrence with an incidence of 1 to 3 percent. Two patients with this problem are presented who were treated with streptokinase followed by conventional anticoagulation therapy with heparin and warfarin. Near total resolution of the thromboses was accomplished in both patients. In follow-up periods of nine and 20 months, the patients have remained asymptomatic. An aggressive approach to this problem may decrease the current high morbidity.

Serodiagnosis of La Crosse virus infections in humans

Serological diagnoses of human infections with California serogroup viruses are usually made by means of complement fixation or hemagglutination inhibition tests or both. An analysis of antibody titers in sera from 128 humans with California (La Crosse) virus infections indicated that exclusive use of the complement fixation tests would have detected only 50% of the actual seroconversions, whereas hemagglutination inhibition and neutralization tests alone would have been sufficient to make the diagnosis in 79.3% and 84.8% of the cases, respectively. These and other results presented demonstrate that the complement fixation test is not sufficiently useful as a primary tool for diagnosis of La Crosse virus infections. We suggest the use of the hemagglutination inhibition test for preliminary screening of sera from individuals with suspect infections caused by California serogroup viruses. The neutralization test should then be used or confirmation and subtype identification. If hemagglutination inhibition and neutralization titers are high and stable, the complement fixation test should then be used as a last, but specific, resort.