Air pollution and the sequelae of COVID-19 patients: A multistate analysis

IMPORTANCE

Recent evidence links air pollution to the severity COVID-19 symptoms and to death from the disease. To date, however, few studies have assessed whether air pollution affects the sequelae to more severe states or recovery from COVID-19 in a cohort with individual data.

OBJECTIVE

To assess how air pollution affects the transition to more severe COVID-19 states or to recovery from COVID-19 infection in a cohort with detailed patient information.

DESIGN AND OUTCOMES

We used a cohort design that followed patients admitted to hospital in the Kaiser Permanente Southern California (KPSC) Health System, which has 4.7 million members with characteristics similar to the general population. Enrollment began on 06/01/2020 and ran until 01/30/2021 for all patients admitted to hospital while ill with COVID-19. All possible states of sequelae were considered, including deterioration to intensive care, to death, discharge to recovery, or discharge to death. Transition risks were estimated with a multistate model. We assessed exposure using chemical transport model that predicted ambient concentrations of nitrogen dioxide, ozone, and fine particulate matter (PM2.5) at a 1 km scale.

RESULTS

Each increase in PM2.5 concentration equivalent to the interquartile range was associated with increased risk of deterioration to intensive care (HR of 1.16; 95% CI: 1.12-1.20) and deterioration to death (HR of 1.11; 95% CI: 1.04-1.17). Results for ozone were consistent with PM2.5 effects, but ozone also affected the transition from recovery to death: HR of 1.24 (95% CI: 1.01-1.51). NO2 had weaker effects but displayed some elevated risks.

CONCLUSIONS

PM2.5 and ozone were significantly associated with transitions to more severe states while in hospital and to death after discharge from hospital. Reducing air pollution could therefore lead to improved prognosis for COVID-19 patients and a sustainable means of reducing the health impacts of coronaviruses now and in the future.

Beyond clinical outcomes: Case control study of the role of race in disruptive life events for people with serious mental illness

OBJECTIVE

To understand how race and serious mental illness (SMI) interact for disruptive life events defined as financial (bankruptcy and judgement filings), and non-financial (arrests).

METHODS

Patients were adults with schizophrenia (SCZ; N = 16,159) or bipolar I disorder (BPI; N = 30,008) matched 1:1 to patients without SMI (non-SMI) from health systems in Michigan and Southern California during 1/1/2007 through 12/31/2018. The main exposure was self-reported race, and the outcome was disruptive life events aggregated by Transunion. We hypothesized that Black patients with SCZ or BPI would be the most likely to experience a disruptive life event when compared to Black patients without SMI, and all White or Asian patients regardless of mental illness.

RESULTS

Black patients with SCZ had the least likelihood (37% lower) and Asian patients with BPI had the greatest likelihood (2.25 times higher) of experiencing a financial disruptive life event among all patients in the study. There was no interaction of race with either SCZ or BPI for experiencing an arrest. The findings did not support our hypotheses for patients with SCZ and partially supported them for patients with BPI.

CONCLUSIONS

Clinical initiatives to assess social determinants of health should consider a focus on Asian patients with BPI.

Using natural language processing to identify the status of homelessness and housing instability among serious illness patients from clinical notes in an integrated healthcare system

Background

Efficiently identifying the social risks of patients with serious illnesses (SIs) is the critical first step in providing patient-centered and value-driven care for this medically vulnerable population.

Objective

To apply and further hone an existing natural language process (NLP) algorithm that identifies patients who are homeless/at risk of homeless to a SI population.

Methods

Patients diagnosed with SI between 2019 and 2020 were identified using an adapted list of diagnosis codes from the Center for Advance Palliative Care from the Kaiser Permanente Southern California electronic health record. Clinical notes associated with medical encounters within 6 months before and after the diagnosis date were processed by a previously developed NLP algorithm to identify patients who were homeless/at risk of homelessness. To improve the generalizability to the SI population, the algorithm was refined by multiple iterations of chart review and adjudication. The updated algorithm was then applied to the SI population.

Results

Among 206 993 patients with a SI diagnosis, 1737 (0.84%) were identified as homeless/at risk of homelessness. These patients were more likely to be male (51.1%), age among 45-64 years (44.7%), and have one or more emergency visit (65.8%) within a year of their diagnosis date. Validation of the updated algorithm yielded a sensitivity of 100.0% and a positive predictive value of 93.8%.

Conclusions

The improved NLP algorithm effectively identified patients with SI who were homeless/at risk of homelessness and can be used to target interventions for this vulnerable group.

Association of neighborhood gentrification and residential moves with hypertension and diabetes control in Los Angeles County, 2014-2019: A retrospective cohort study

OBJECTIVE

To examine whether gentrification exposure is associated with future hypertension and diabetes control.

METHODS

Linking records from an integrated health care system to census-tract characteristics, we identified adults with hypertension and/or diabetes residing in stably low-SES census tracts in 2014 (n = 69,524). We tested associations of census tract gentrification occurring between 2015 and 2019 with participants' disease control in 2019. Secondary analyses considered the role of residential moves (possible displacement), race and ethnicity, and age.

RESULTS

Gentrification exposure was associated with improved odds of hypertension control (aOR: 1.08; 95% CI: 1.00, 1.17), especially among non-Hispanic Whites and adults >65 years. Gentrification was not associated with diabetes control overall, but control improved in the Hispanic subgroup. Disease control was similar regardless of residential moves in the overall sample, but disparate associations emerged in models stratified by race and ethnicity.

CONCLUSIONS

Residents of newly gentrifying neighborhoods may experience modestly improved odds of hypertension and/or diabetes control, but associations may differ across population subgroups.

POLICY IMPLICATIONS

Gentrification may support-or at least not harm-cardiometabolic health for some residents. City leaders and health systems could partner with impacted communities to ensure that neighborhood development meets the goals and health needs of all residents and does not exacerbate health disparities.

Assessment of Disruptive Life Events for Individuals Diagnosed With Schizophrenia or Bipolar I Disorder Using Data From a Consumer Credit Reporting Agency

Importance

There is a dearth of population-level data on major disruptive life events (defined here as arrests by a legal authority, address changes, bankruptcy, lien, and judgment filings) for patients with bipolar I disorder (BPI) or schizophrenia, which has limited studies on mental health and treatment outcomes.

Objective

To conduct a population-level study on disruptive life events by using publicly available data on disruptive life events, aggregated by a consumer credit reporting agency in conjunction with electronic health record (EHR) data.

Design, Setting, and Participants

This study used EHR data from 2 large, integrated health care systems, Kaiser Permanente Southern California and Henry Ford Health. Cohorts of patients diagnosed from 2007 to 2019 with BPI or schizophrenia were matched 1:1 by age at analysis, age at diagnosis (if applicable), sex, race and ethnicity, and Medicaid status to (1) an active comparison group with diagnoses of major depressive disorder (MDD) and (2) a general health (GH) cohort without diagnoses of BPI, schizophrenia, or MDD. Patients with diagnoses of BPI or schizophrenia and their respective comparison cohorts were matched to public records data aggregated by a consumer credit reporting agency (98% match rate). Analysis took place between November 2020 and December 2022.

Main Outcomes and Measures

The differences in the occurrence of disruptive life events among patients with BPI or schizophrenia and their comparison groups.

Results

Of 46 167 patients, 30 008 (65%) had BPI (mean [SD] age, 42.6 [14.2] years) and 16 159 (35%) had schizophrenia (mean [SD], 41.4 [15.1] years). The majoriy of patients were White (30 167 [65%]). In addition, 18 500 patients with BPI (62%) and 6552 patients with schizophrenia (41%) were female. Patients with BPI were more likely to change addresses than patients in either comparison cohort (with the incidence ratio being as high as 1.25 [95% CI, 1.23-1.28]) when compared with GH cohort. Patients with BPI were also more likely to experience any of the financial disruptive life events with odds ratio ranging from 1.15 [95% CI, 1.07-1.24] to 1.50 [95% CI, 1.42-1.58]). The largest differences in disruptive life events were seen in arrests of patients with either BPI or schizophrenia compared with GH peers (3.27 [95% CI, 2.84-3.78] and 3.04 [95% CI, 2.57-3.59], respectively). Patients with schizophrenia had fewer address changes and were less likely to experience a financial event than their matched comparison cohorts.

Conclusions and Relevance

This study demonstrated that data aggregated by a consumer credit reporting agency can support population-level studies on disruptive life events among patients with BPI or schizophrenia.

Abstract P163: Lessons Learned From the Implementation of a Produce Prescriptions Pre-Randomized Clinical Trial in an Integrated Health Care System

Introduction: Produce prescriptions are one of several approaches that have been receiving national attention to increase food security while also improving diet for patients with diet-related health challenges. Implementation of produce prescriptions vary widely, from food vouchers to tailored, pre-arranged weekly home deliveries. Our study focuses on sending weekly curated produce boxes, scaled by family size up to 5 members. We curated 5 different culturally themed boxes for participants to choose from with the ability to change theme at any time throughout the study period. It was our hypothesis that pre-curated, culturally varied boxes would allow to address patient food preferences to assure continued retention.

Methods: This produce prescriptions pre-randomized clinical trial is being conducted at Kaiser Permanente Southern California, an integrated health care system with over 4.5M members. Adult members with uncontrolled diabetes with recent Hemoglobin A1c >7.5% or 8% (if >65 years or certain comorbid conditions) were pre-randomized into a high or low-dose (intervention) versus usual care group. Surveys are conducted at 4 different time points (2 and 8-week, 3 and 6 months) for participants pre-randomized to the intervention group. The eight week and 3 months survey that are now completed provide participant feedback on utility and satisfaction of both the food and recipes provided.

Results: Recruitment has closed to enrollment; the intervention is slated to end January 2023. There were 150 participants enrolled in each arm for a total 450 participants. The average age at enrollment was 59 years. Over 62% reported currently being unemployed, retired or disabled. Just over half (51%), reported Spanish as their preferred language. Although diabetes was the main eligibility for this study, participants on average had 2-3 additional comorbidities, with 65% also being diagnosed with hypertension and 8.5% having congestive heart failure. Generally, respondents (N=187) considered the foods culturally appropriate with 69% indicating being familiar with the foods delivered and 70% knew how to prepare the foods. Recipes were moderately useful familiarizing participants with new foods (26%). Only 41% reported that of the foods new to them, they would use again in the future. Deliveries could be improved for future with participants overwhelmingly asking for more fruit, vegetables, legumes (98%, 94%, 71%), while also stating diary would be important to add to the deliveries (94%). Overall, 72% of participants reporting being very satisfied with the weekly produce deliveries and 81% stated the food helped them eat healthier throughout the week.

Conclusions: Weekly produce deliveries are a promising approach to promote healthier eating providing more variety and autonomy in choices will likely increase use of produce and overall satisfaction in such programs.

COST-EFFECTIVENESS OF BENRALIZUMAB VERSUS MEPOLIZUMAB AND DUPILUMAB IN PATIENTS WITH SEVERE UNCONTROLLED EOSINOPHILIC ASTHMA IN SPAIN

OBJECTIVE

To assess the cost-effectiveness of benralizumab (benra) vs. mepolizumab (mepo) and dupilumab (dupi) for the treatment of patients with severe uncontrolled asthma from the Spanish Health System perspective.

METHODS

Exacerbations avoided, quality-adjusted life years (QALYs) gained and costs in a 5-year period were estimated with a Markov model for a cohort of 1,000 patients in which, based on published evidence, 31% of the patients received biologics + oral corticosteroids (OCS) and 69% received only biologics. Efficacy data (exacerbation reduction and OCS elimination) were derived from a matching-adjusted indirect comparison. Published EQ-5D utilities per health state (biologic alone, biologic + OCS, standard of care + OCS, exacerbations, and post-exacerbations) were used for QALY estimation. Utility decrements associated with exacerbation management [-0.1 (OCS or emergency visits), -0.2 (hospitalization)] derived from the literature were applied. Costs (€, 2022) included drug acquisition (ex-factory price), administration and disease management. An expert panel (2 pneumologists and 1 pharmacist) validated all inputs.

RESULTS

Benra was more effective (52.21 QALYs) than mepo (51.39 QALYs) and dupi (51.30 QALYs). Benra avoided more exacerbations (2.87 exacerbations) compared to mepo (4.70 exacerbations) and dupi (5.11 exacerbations) for the 5-year horizon. Total costs/patient were €56,093.77 (benra), €59,280.45 (mepo) and €62,991.76 (dupi), resulting in benra dominating (more QALYs with lower costs) vs. mepo and dupi.

CONCLUSIONS

Benralizumab can be considered as a dominant treatment alternative vs. other biologic drugs for the treatment of uncontrolled severe eosinophilic asthma patients in Spain.

Development and assessment of a natural language processing model to identify residential instability in electronic health records’ unstructured data: a comparison of 3 integrated healthcare delivery systems

Objective

To evaluate whether a natural language processing (NLP) algorithm could be adapted to extract, with acceptable validity, markers of residential instability (ie, homelessness and housing insecurity) from electronic health records (EHRs) of 3 healthcare systems.

Materials and methods

We included patients 18 years and older who received care at 1 of 3 healthcare systems from 2016 through 2020 and had at least 1 free-text note in the EHR during this period. We conducted the study independently; the NLP algorithm logic and method of validity assessment were identical across sites. The approach to the development of the gold standard for assessment of validity differed across sites. Using the EntityRuler module of spaCy 2.3 Python toolkit, we created a rule-based NLP system made up of expert-developed patterns indicating residential instability at the lead site and enriched the NLP system using insight gained from its application at the other 2 sites. We adapted the algorithm at each site then validated the algorithm using a split-sample approach. We assessed the performance of the algorithm by measures of positive predictive value (precision), sensitivity (recall), and specificity.

Results

The NLP algorithm performed with moderate precision (0.45, 0.73, and 1.0) at 3 sites. The sensitivity and specificity of the NLP algorithm varied across 3 sites (sensitivity: 0.68, 0.85, and 0.96; specificity: 0.69, 0.89, and 1.0).

Discussion

The performance of this NLP algorithm to identify residential instability in 3 different healthcare systems suggests the algorithm is generally valid and applicable in other healthcare systems with similar EHRs.

Conclusion

The NLP approach developed in this project is adaptable and can be modified to extract types of social needs other than residential instability from EHRs across different healthcare systems.

Normative Data for Executive Function and Emotion Interaction Assessment in Adolescents from Rural Areas

Objective

The present work is part of the ongoing project of examining the validation and standardization of the Executive Functions and Emotion Assessment for Adolescents with Risk Behaviors (EFEAA) test in the rural areas of Northwest Mexico. The objectives of the present study were (1) to examine the effects of age and risk behavior on emotionally interfered working memory ability, measured as performance on the Emotionally Interfered Working Memory Task (EIWMT) section of the EFEAA in a group of healthy adolescents from rural areas; and (2) to use these results to construct normative data that can be used in clinical practice.

Participants and Method

A total of 275 adolescents, 14.1 years old, geographically distributed among northwest Mexico were included in the sample. They were individually assessed using the Montreal Cognitive Assessment, Risk Behavior Questionnaire, including: sexual risk behavior, impulsiveness, drug, alcohol, and tobacco consumption, unhealthy food intake, and physical inactivity; for measuring emotion-cognition interaction we used the EIWMT.

Results

Results of this study present a database supported by factors of risk behavior and working memory, which includes: predictors for conduct disorders, drug use, and delinquency, in addition to correlations between the performance of emotionally interfered working memory and risk behaviors associated to health. Percentile and normal distribution tables were generated, demonstrating that there is a high prevalence of risk behavior in rural areas.

Conclusions

This study demonstrates data related to rural areas in northwest Mexico, a region where adolescents are frequently involved in risk behaviors. Additionally, protective factors are understudied in Mexico-US border cities. Further analyses are needed to find reward delay skills on the studied sample as well as urban area comparisons.

Streptococcus agalactiae: prevention and vaccine development

Streptococcus agalactiae, group B Streptococcus (SGB), is the most important cause of morbi-mortality among newborn population, and an important pathogen among immunossupressed adult patients. Despite the advances in the treatment and prevention of neonatal infections as a consequence of implementation of national and international recommendations for prevention of infection, there are still some improvements for the final control of the disease. In this sense, the vaccination against SGB could be an effective measure for the prevention of disease in those cases where intrapartum prophylaxis is not useful and in adult patients with risk factors for invasive infection due to SGB. This review summarizes the efforts made until now in order to establish the control of the infection, and brings some information on the current state-of-the art of vaccines against SGB, in which different strategies in their design have been used.

Current strategies to prevent transmission of prions by human plasma derivatives

Protein products prepared from pooled human plasma are an essential class of therapeutics used mostly to control bleeding and/or immunological disorders. Because of the human origin of the starting material, there is a risk that these products may possibly transmit prions causing variant Creutzfeldt-Jakob disease (vCJD). No case of transmission of prions by plasma products has been observed. Case-by-case measures implemented in various countries, and several technical factors may contribute, to various degrees, to the prevention of the risk of transmission of prions by plasma products. Those measures include (a) the epidemiological surveillance of population in countries with cases of vCJD and/or bovine spongiform encephalopathies (BSE), (b) the deferral of blood donors who traveled or resided, for specific periods of time, to countries with BSE, or who received transfusion or tissue transplant, (c) the removal of leucocytes in plasma used for fractionation, and, last but not least, (d) the removal of the prion agents during the complex industrial fractionation process used to prepare plasma products. Numerous experimental infectivity studies, involving the spiking of brain-derived infectious materials, have demonstrated that several fractionation steps, in particular ethanol fractionation, depth filtration, and chromatography, can remove several logs of prions. Removal is explained by the distinct hydrophobic and aggregative properties of the prion proteins. In addition, nanofiltration using multi-layer membranes of 75 nm or smaller, which is commonly used for removing viruses from coagulation factors and immunoglobulins products, can remove more than 3-5 logs of spiked prions, presumably by size-exclusion and trapping mechanisms. Therefore, the risk of transmission of vCJD by human plasma products appears remote, but caution should prevail since the biochemical nature of the infectious agent in human blood is still unknown.

International standards for minimum potency of anti-A and anti-B blood grouping reagents: evaluation of candidate preparations in an international collaborative study

BACKGROUND AND OBJECTIVES

The aim of the study was to evaluate lyophilized monoclonal IgM anti-A and anti-B preparations for use as international standards (IS) to specify recommended minimum potencies of anti-A and anti-B blood grouping reagents in tube tests.

MATERIALS AND METHODS

The candidate IS for minimum potency of anti-A and anti-B blood grouping reagents, codes 03/188 and 03/164, respectively, were evaluated against a wide range of commercial anti-A and anti-B blood grouping reagents in an international collaborative study involving 16 laboratories in nine countries. Laboratories titrated 03/188 and 03/164 in parallel with as many commercial anti-A and anti-B blood grouping reagents, respectively, as were available to them, in tube tests according to specified haemagglutination methodology. Three of these laboratories and a further laboratory also titrated 03/188 and 03/164 in parallel with currently available reference preparations for anti-A and anti-B. The ratios of the mean endpoint titres of the anti-A and anti-B reagents to those of 03/188 and 03/164, respectively, within each laboratory were calculated.

RESULTS

The ratios of the mean titres of the anti-A reagents to the mean titre of 03/188 within a laboratory fell within 0.062 and 4, i.e. the potencies of the anti-A reagents were between a sixteenth to four times as strong as 03/188. The ratios of the mean titres of the anti-B reagents to the mean titre of 03/164 within a laboratory also fell within 0.062 and 4, with one outlier.

CONCLUSIONS

By international consensus, a 1 in 8 dilution of the candidate IS for anti-A, 03/188, and a 1 in 4 dilution of the candidate IS for anti-B, 03/164, were considered appropriate to define the recommended minimum potencies of anti-A and anti-B blood grouping reagents, respectively, in tube tests. On the basis of these results, preparations 03/188 and 03/164 were established by the World Health Organization as International Standards for Minimum Potency of Anti-A and Anti-B Blood Grouping Reagents respectively, and by the US Food and Drug Administration Center for Biologics Evaluation and Research as Minimum Potency Reference Reagents.

An International Standard for specifying the minimum potency of anti-D blood-grouping reagents: evaluation of a candidate preparation in an international collaborative study

BACKGROUND AND OBJECTIVES

The aim of this study was to evaluate a lyophilized monoclonal immunoglobulin M (IgM) anti-D preparation for use as an International Standard to specify a recommended minimum acceptable potency of anti-D blood-grouping reagents.

MATERIALS AND METHODS

The candidate International Standard (99/836) for specifying the minimum potency of anti-D blood-grouping reagents was evaluated against a wide range of commercial anti-D blood-grouping reagents in an international collaborative study involving 20 laboratories in 13 countries. Laboratories titrated reconstituted 99/836, in parallel with as many commercial anti-D blood-grouping reagents as were available to them, in tube tests according to specified haemagglutination methodology for low-protein (e.g. monoclonal IgM) and high-protein (e.g. polyclonal) reagents. The ratios of the mean end-point titres of the reagents to that of 99/836 within each laboratory were calculated.

RESULTS

The ratios of the mean titres of the low-protein reagents to the mean titre of 99/836 within a laboratory fell between 0.25 and 2 for 43 of the 45 low-protein anti-D reagents tested (i.e. the potencies of the low-protein reagents compared with 99/836 were between a 1:4 dilution of 99/836 to twice as potent as 99/836). The ratios of the mean titres of the high-protein reagents to the mean titre of 99/836 within a laboratory fell within 0.125 and 1 for eight out of the 10 high protein reagents tested.

CONCLUSIONS

By international consensus, a 1:3 dilution of reconstituted 99/836 was deemed appropriate to define a recommended minimum acceptable potency of low-protein anti-D blood-grouping reagents. A 1:8 dilution of reconstituted 99/836 was deemed appropriate to define a recommended minimum acceptable potency of high-protein anti-D blood-grouping reagents. On the basis of the results presented here, 99/836 was established by the World Health Organization as the 1st International Standard for specifying the minimum potency of anti-D blood-grouping reagents, in tube tests.

Experimental analysis and modified rotor description of the infrared fundamental band of HCl in Ar, Kr, and Xe solutions

We report an experimental study of the rotovibrational fundamental PQR-band shapes in the IR absorption spectra of HCl dissolved in condensed rare gases in a wide range of temperatures. The effective vibrational frequencies are determined from analysis of the fine rotational structure partially resolved in the band wings. The central Q-branch components appear redshifted with respect to the effective vibrational frequencies, their shifts in different solvents found to match the HCl stretching mode shifts in binary Rg...HCl van der Waals heterodimers. Theoretical quasi-free rotor and modified rotor models are applied to describe evolution of the band profiles at changing thermodynamic conditions. Both models are shown to reproduce equally well the observed spectral density distributions in the band wings. However, the modified rotor formalism that accounts for depopulation of the lower-energy rotational solute states provides better agreement with the experiment in the range of the P- and R-branch maxima. We surmise that the Q branches separated from the measured spectral profiles are formed by transitions between rotationally hindered states of diatomic molecules coupled to the solvent by the local anisotropy of the interaction potential.

WHO Expert Committee on Biological Standardization

This report presents the recommendations of a WHO Expert Committee commissioned to coordinate activities leading to the adoption of international requirements for the production and control of vaccines and other biologicals and the establishment of international biological reference materials. The report starts with a discussion of general issues brought to the Committee's attention and provides information on the status and development of reference materials for various antibodies, antigens, blood products and related substances, cytokines, growth factors, and endocrinological substances. The second part of the report, of particular relevance to manufacturers and national regulatory authorities, contains recommendations for the production and quality control of meningococcal group C conjugate vaccines, guidelines for regulatory expectations for clinical evaluation of vaccines, guidelines for the production and quality control of inactivated oral cholera vaccines and guidelines on viral inactivation and removal procedures intended to assure the viral safety of human blood plasma products.

Structure of rat parvalbumin with deleted AB domain: implications for the evolution of EF hand calcium-binding proteins and possible physiological relevance

Among the EF-hand Ca(2+)-binding proteins, parvalbumin (PV) and calbindin D9k (CaB) have the function of Ca(2+) buffers. They evolved from an ancestor protein through two phylogenetic pathways, keeping one pair of EF-hands. They differ by the extra helix-loop-helix (AB domain) found in PV and by the linker between the binding sites. To investigate whether the deletion of AB in PV restores a CaB-like structure, we prepared and solved the structure of the truncated rat PV (PVratDelta37) by X-ray and NMR. PVratDelta37 keeps the PV fold, but is more compact, having a well-structured linker, which differs remarkably from CaB. PvratDelta37 has no stable apo-form, has lower affinity for Ca(2+) than full-length PV, and does not bind Mg(2+), in contrast to CaB. Structural differences of the hydrophobic core are partially responsible for lowering the calcium-binding affinity of the truncated protein. It can be concluded that the AB domain, like the linker of CaB, plays a role in structural stabilization. The AB domain of PV protects the hydrophobic core, and is required to maintain high affinity for divalent cation binding. Therefore, the AB domain possibly modulates PV buffer function.

Biochemical characterization of the helper component of Cauliflower mosaic virus

The helper component of Cauliflower mosaic virus is encoded by viral gene II. This protein (P2) is dispensable for virus replication but required for aphid transmission. The purification of P2 has never been reported, and hence its biochemical properties are largely unknown. We produced the P2 protein via a recombinant baculovirus with a His tag fused at the N terminus. The fusion protein was purified by affinity chromatography in a soluble and biologically active form. Matrix-assisted laser desorption time-of-flight mass spectrometry demonstrated that P2 is not posttranslationally modified. UV circular dichroism revealed the secondary structure of P2 to be 23% alpha-helical. Most alpha-helices are suggested to be located in the C-terminal domain. Using size exclusion chromatography and aphid transmission testing, we established that the active form of P2 assembles as a huge soluble oligomer containing 200 to 300 subunits. We further showed that P2 can also polymerize as long paracrystalline filaments. We mapped P2 domains involved in P2 self-interaction, presumably through coiled-coil structures, one of which is proposed to form a parallel trimer. These regions have previously been reported to also interact with viral P3, another protein involved in aphid transmission. Possible interference between the two types of interaction is discussed with regard to the biological activity of P2.

Lithium reduces maternal child abuse behaviour: a preliminary report

OBJECTIVE

To find out in child abusing mothers whether aggressiveness in general, but which is directed towards their children in particular, could be reduced by giving lithium.

METHOD

An open trial of lithium in eight child-abusing mothers. Assessment of aggression using Yudofsky's Overt Aggression Scale.

RESULTS

There was a statistically significant reduction (P < 0.05) in aggressiveness to the children and to inanimate objects.

CONCLUSION

Lithium could be an effective adjunct in the social and psychological treatment of parents who abuse their children. An adequately powered controlled study testing lithium against placebo over a longer period of treatment and observation would be useful.

Kinetics and characterization of cellular responses in the peritoneal cavity of mice infected with Taenia crassiceps

Changes in the leukocyte population of the peritoneal cavity ensue immediately after infection with Taenia crassiceps metacestodes. Basophils and neutrophils decrease, whereas macrophages, monocytes, and lymphocytes increase to reach only modest levels by 6 wk and then diminish to nearly disappear by 15 wk when the parasite begins rapid reproduction. Eosinophils also appear early in infection, but then abate to lower levels that persist. In late infections, when the mass of cysticerci equals that of the mouse, the cysticerci grow among surprisingly few inflammatory cells. Mingling with the peritoneal inflammatory cells is a number of odd-looking cells that could correspond to the metaplasic mesothelial cells of the host or be of parasite origin. These cells are multinucleated, they aggregate in varigerated clusters, and form cystic structures in vitro; they also bind specific anti-T. crassiceps antibodies and specific T. crassiceps DNA probes in their nuclei. When the peritoneal cell exudate is reinjected intraperitoneally into naive mice, the odd-looking cells subsist for months, inducing in the host the synthesis of specific anti-T. crassiceps antibodies and immune resistance to challenge but do not reassemble into cysticerci even after 6 mo of inoculation. The early appearance and the immunogenic and antigenic properties of these odd-looking cells suggest they are important protagonists in the early host-parasite confrontation when the outcome of infection is set.

WHO Expert Committee on Biological Standardization: highlights of the 50th meeting, October 1999

Biological medicines, which include vaccines, blood products and biological therapeutics, have historically played a dominant role in improving world health and are expected to make an increasingly important contribution to public health in the 21st century. Recent scientific and biotechnological developments have opened the way to novel products, new production methods and to highly sensitive assay procedures. However, the nature of biologicals, and especially new vaccines, blood products and therapeutics, raises particular questions regarding their standardization and quality control. These relate both to efficacy and to safety not only for the individual recipient but also for the population at large. Such advances highlight the complex issues surrounding standardization and control of biologicals, issues that need to be addressed on an international level.

Backbone dynamics and solution structure refinement of the 15N-labeled human oncogenic protein p13MTCP1: comparison with X-ray data

Two related oncogenes, TCL1 and MTCP1, are overexpressed in certain T-cell prolymphocytic leukemias as a result of chromosomal rearrangements that involve the translocation of one T-cell receptor gene to either chromosome 14q32 or Xq28, respectively. The human oncoprotein p13MTCP1 is coded by the MTCP1 gene and its primary sequence is highly and only homologous to that of p14TCL1, the product of TCL1. These two proteins likely represent the first members of a new family of oncogenic proteins. A previous model of the three-dimensional solution structure of p13MTCP1 was determined recently using exclusively homonuclear proton two-dimensional NMR methods and, almost simultaneously, high-resolution crystal structures of p13MTCP1 and p14TCL1 appeared in the literature. In order to gain more insight into the details of the solution structure, we uniformly labeled p13MTCP1 with nitrogen-15. The refined structure benefits from 520 additional NOEs, extracted from either 15N-edited 3D experiments or homonuclear 2D NOESY recorded at 800 MHz, and from a nearly complete set of phi angular restraints. Measurements of 15N spin relaxation times and heteronuclear 15N[1H]NOEs at two magnetic field strengths provided additional insights into the dynamics of the protein backbone. On the basis of these new results, a putative binding surface for this particular class of oncogenes is discussed.