Outpatient COVID-19 convalescent plasma recipient antibody thresholds correlated to reduced hospitalizations within a randomized trial

BACKGROUNDCOVID-19 convalescent plasma (CCP) virus-specific antibody levels that translate into recipient posttransfusion antibody levels sufficient to prevent disease progression are not defined.METHODSThis secondary analysis correlated donor and recipient antibody levels to hospitalization risk among unvaccinated, seronegative CCP recipients within the outpatient, double-blind, randomized clinical trial that compared CCP to control plasma. The majority of COVID-19 CCP arm hospitalizations (15/17, 88%) occurred in this unvaccinated, seronegative subgroup. A functional cutoff to delineate recipient high versus low posttransfusion antibody levels was established by 2 methods: (i) analyzing virus neutralization-equivalent anti-Spike receptor-binding domain immunoglobulin G (anti-S-RBD IgG) responses in donors or (ii) receiver operating characteristic (ROC) curve analysis.RESULTSSARS-CoV-2 anti-S-RBD IgG antibody was volume diluted 21.3-fold into posttransfusion seronegative recipients from matched donor units. Virus-specific antibody delivered was approximately 1.2 mg. The high-antibody recipients transfused early (symptom onset within 5 days) had no hospitalizations. A CCP-recipient analysis for antibody thresholds correlated to reduced hospitalizations found a statistical significant association between early transfusion and high antibodies versus all other CCP recipients (or control plasma), with antibody cutoffs established by both methods-donor-based virus neutralization cutoffs in posttransfusion recipients (0/85 [0%] versus 15/276 [5.6%]; P = 0.03) or ROC-based cutoff (0/94 [0%] versus 15/267 [5.4%]; P = 0.01).CONCLUSIONIn unvaccinated, seronegative CCP recipients, early transfusion of plasma units in the upper 30% of study donors' antibody levels reduced outpatient hospitalizations. High antibody level plasma units, given early, should be reserved for therapeutic use.TRIAL REGISTRATIONClinicalTrials.gov NCT04373460.FUNDINGDepartment of Defense (W911QY2090012); Defense Health Agency; Bloomberg Philanthropies; the State of Maryland; NIH (3R01AI152078-01S1, U24TR001609-S3, 1K23HL151826NIH); the Mental Wellness Foundation; the Moriah Fund; Octapharma; the Healthnetwork Foundation; the Shear Family Foundation; the NorthShore Research Institute; and the Rice Foundation.

Sex and gender differences in adverse events following receipt of influenza and COVID-19 vaccination among healthcare workers

Introduction

Active and passive surveillance studies have found that a greater proportion of females report adverse events (AE) following receipt of either the COVID-19 or seasonal influenza vaccine compared to males. We sought to determine the intersection of biological sex and sociocultural gender differences in prospective active reporting of vaccine outcomes, which remains poorly characterized.

Methods

This cohort study enrolled Johns Hopkins Health System healthcare workers (HCWs) who were recruited from the annual fall 2019-2022 influenza vaccine and the fall 2022 COVID-19 bivalent vaccine campaigns. Vaccine recipients were enrolled the day of vaccination and AE surveys were administered two days post-vaccination (DPV) for bivalent COVID-19 and Influenza vaccine recipients. Data were collected regarding the presence of a series of solicited local and systemic AEs. Open-ended answers about participants' experiences with AEs also were collected for the COVID-19 vaccine recipients.

Results

Females were more likely to report local AEs after influenza (OR=2.28, p=0.001) or COVID-19 (OR=2.57, p=0.008) vaccination compared to males, regardless of age or race. Males and females had comparable probabilities of reporting systemic AEs after influenza (OR=1.18, p=0.552) or COVID-19 (OR=0.96, p=0.907) vaccination. Exogenous hormones from birth control use did not impact the rates of reported AEs following COVID-19 vaccination among reproductive-aged female HCWs. Women reported more interruptions in their daily routine following COVID-19 vaccination than men and were more likely to seek out self-treatment. More women than men scheduled their COVID-19 vaccination before their days off in anticipation of AEs.

Conclusions

Our findings highlight the need for sex- and gender-inclusive policies to inform more effective occupational health vaccination strategies. Further research is needed to evaluate the potential disruption of AEs on occupational responsibilities following mandated vaccination for healthcare workers and to more fully characterize the post-vaccination behavioral differences between men and women.

KEY MESSAGE

What is already known on this topic: ⇒ Among diversely aged adults 18-64 years, females report more AEs to vaccines, including the influenza and COVID-19 vaccines, than males.⇒ Vaccine AEs play a role in shaping vaccine hesitancy and uptake.⇒ Vaccine uptake related to influenza and COVID-19 are higher among men than women.⇒ Research that addresses both the sex and gender disparities of vaccine outcomes and behaviors is lacking.What this study adds: ⇒ This prospective active reporting study uses both quantitative and qualitative survey data to examine sex and gender differences in AEs following influenza or COVID-19 vaccination among a cohort of reproductive-aged healthcare workers.How this study might affect research, practice, or policy: ⇒ Sex and gender differences in AEs and perceptions relating to vaccination should drive the development of more equitable and effective vaccine strategies and policies in occupational health settings.

Outpatient COVID-19 convalescent plasma recipient antibody thresholds correlated to reduced hospitalizations within a randomized trial

BACKGROUND

The COVID-19 convalescent plasma (CCP) viral specific antibody levels that translate into recipient post-transfusion antibody levels sufficient to prevent disease progression is not defined.

METHODS

This secondary analysis correlated donor and recipient antibody levels to hospitalization risk among unvaccinated, seronegative CCP recipients within the outpatient, double blind, randomized clinical trial that compared CCP to control plasma. The majority of COVID-19 CCP arm hospitalizations (15/17, 88%) occurred in this unvaccinated, seronegative subgroup. A functional cutoff to delineate recipient high versus low post-transfusion antibody levels was established by two methods: 1) analyzing virus neutralization-equivalent anti-S-RBD IgG responses in donors or 2) receiver operating characteristic (ROC) analysis.

RESULTS

SARS-CoV-2 anti-S-RBD IgG antibody was diluted by a factor of 21.3 into post-transfusion seronegative recipients from matched donor units. Viral specific antibody delivered approximated 1.2 mg. The high antibody recipients transfused early (symptom onset within 5 days) had no hospitalizations. A CCP recipient analysis for antibody thresholds correlated to reduced hospitalizations found a significant association with Fisher's exact test between early and high antibodies versus all other CCP recipients (or control plasma) with antibody cutoffs established by both methods-donor virus neutralization-based cutoff: (0/85; 0% versus 15/276; 5.6%) p=0.03 or ROC based cutoff: (0/94; 0% versus 15/267; 5.4%) p=0.01.

CONCLUSION

In unvaccinated, seronegative CCP recipients, early transfusion of plasma units corresponding to the upper 30% of all study donors reduced outpatient hospitalizations. These high antibody level plasma units, given early, should be reserved for therapeutic use.Trial registration: NCT04373460.

FUNDING

Defense Health Agency and others.

Three doses of COVID-19 mRNA vaccine induce class-switched antibody responses in inflammatory arthritis patients on immunomodulatory therapies

Patients with inflammatory arthritis (IA) are at increased risk of severe COVID-19 due to medication-induced immunosuppression that impairs host defenses. The aim of this study was to assess antibody and B cell responses to COVID-19 mRNA vaccination in IA patients receiving immunomodulatory therapies. Adults with IA were enrolled through the Johns Hopkins Arthritis Center and compared with healthy controls (HC). Paired plasma and peripheral blood mononuclear cell (PBMC) samples were collected prior to and 30 days or 6 months following the first two doses of mRNA vaccines (D2; HC=77 and IA=31 patients), or 30 days following a third dose of mRNA vaccines (D3; HC=11 and IA=96 patients). Neutralizing antibody titers, total binding antibody titers, and B cell responses to vaccine and Omicron variants were analyzed. Anti-Spike (S) IgG and S-specific B cells developed appropriately in most IA patients following D3, with reduced responses to Omicron variants, and negligible effects of medication type or drug withholding. Neutralizing antibody responses were lower compared to healthy controls after both D2 and D3, with a small number of individuals demonstrating persistently undetectable neutralizing antibody levels. Most IA patients respond as well to mRNA COVID-19 vaccines as immunocompetent individuals by the third dose, with no evidence of improved responses following medication withholding. These data suggest that IA-associated immune impairment may not hinder immunity to COVID-19 mRNA vaccines in most individuals.

Development and characterization of a plant-derived norovirus-like particle vaccine

BACKGROUND

Norovirus (NoV) is the most common cause of diarrheal episodes globally. Issues with in vitro cultivation systems, genetic variation, and animal models have hindered vaccine development. Plant-derived virus-like particles (VLPs) may address some of these concerns because they are highly immunogenic, can be administered by different routes, and can be rapidly produced to accommodate emerging viral strains.

METHODS

NoV VLPs (NoVLP) composed of the surface viral protein (VP) 1 of the GI and GII genogroups were produced in Nicotiana benthamiana using an Agrobacterium tumefaciens-based recombinant transient expression system. Leaves from infiltrated plants were harvested and NoVLPs were extracted and purified. The safety and immunogenicity of the GII.4 NoVLP, the genotype currently causing most human disease, were subsequently examined in rabbits and mice.

RESULTS

Fifteen GI and GII NoVLPs were successfully expressed in N. benthamiana and were structurally similar to NoV virions, as determined by cryogenic transmission electron microscopy. The NoVLP was well-tolerated, with no local or systemic signs of toxicity in rabbits. Three intramuscular doses of the GII.4 NoVLP adjuvanted with aluminum hydroxide induced robust IgG titers, IgG-secreting cells, histo-blood group antigen blocking titers, and IFNγ-secreting T cells in mice. In addition to circulating antibodies, oral administration of the NoVLP in mice induced significant IgA levels in feces, indicative of a mucosal response.

CONCLUSIONS

The plant-made NoVLP vaccine was safe and immunogenic in mice and rabbits. Multi-modal vaccination, combining oral and intramuscular administration could be considered for future clinical development to maximize systemic and mucosal immune responses.

The intersection of biological sex and gender in adverse events following seasonal influenza vaccination in older adults

BACKGROUND

Women/females report more adverse events (AE) following immunization than men/males for many vaccines, including the influenza and COVID-19 vaccines. This discrepancy is often dismissed as a reporting bias, yet the relative contributions of biological sex and gender are poorly understood. We investigated the roles of sex and gender in the rate of AE following administration of the high-dose seasonal influenza vaccine to older adults (≥ 75 years) using an AE questionnaire administered 5-8 days post-vaccination. Participant sex (male or female) was determined by self-report and a gender score questionnaire was used to assign participants to one of four gender categories (feminine, masculine, androgynous, or undifferentiated). Sex steroid hormones and inflammatory cytokines were measured in plasma samples collected prior to vaccination to generate hypotheses as to the biological mechanism underpinning the AE reported.

RESULTS

A total of 423 vaccines were administered to 173 participants over four influenza seasons (2019-22) and gender data were available for 339 of these vaccinations (2020-22). At least one AE was reported following 105 vaccinations (25%), by 23 males and 82 females. The majority of AE occurred at the site of injection, were mild, and transient. The odds of experiencing an AE were 3-fold greater in females than males and decreased with age to a greater extent in females than males. The effects of gender, however, were not statistically significant, supporting a central role of biological sex in the occurrence of AE. In males, estradiol was significantly associated with IL-6 and with the probability of experiencing an AE. Both associations were absent in females, suggesting a sex-specific effect of estradiol on the occurrence of AE that supports the finding of a biological sex difference.

CONCLUSIONS

These data support a larger role for biological sex than for gender in the occurrence of AE following influenza vaccination in older adults and provide an initial investigation of hormonal mechanisms that may mediate this sex difference. This study highlights the complexities of measuring gender and the importance of assessing AE separately for males and females to better understand how vaccination strategies can be tailored to different subsets of the population.

Spike-protein proteolytic antibodies in COVID-19 convalescent plasma contribute to SARS-CoV-2 neutralization

Understanding the mechanisms of antibody-mediated neutralization of SARS-CoV-2 is critical in combating the COVID-19 pandemic. Based on previous reports of antibody catalysis, we investigated the proteolysis of spike (S) by antibodies in COVID-19 convalescent plasma (CCP) and its contribution to viral neutralization. Quenched fluorescent peptides were designed based on S epitopes to sensitively detect antibody-mediated proteolysis. We observed epitope cleavage by CCP from different donors which persisted when plasma was heat-treated or when IgG was isolated from plasma. Further, purified CCP antibodies proteolyzed recombinant S domains, as well as authentic viral S. Cleavage of S variants suggests CCP antibody-mediated proteolysis is a durable phenomenon despite antigenic drift. We differentiated viral neutralization occurring via direct interference with receptor binding from that occurring by antibody-mediated proteolysis, demonstrating that antibody catalysis enhanced neutralization. These results suggest that antibody-catalyzed damage of S is an immunologically relevant function of neutralizing antibodies against SARS-CoV-2.

Third and Fourth Vaccine Doses Broaden and Prolong Immunity to SARS-CoV-2 in Adult Patients with Immune-Mediated Inflammatory Diseases

Previous studies have reported impaired humoral responses after SARS-CoV-2 mRNA vaccination in patients with immune-mediated inflammatory diseases (IMIDs), particularly those treated with anti-TNF biologics. We previously reported that IMID patients diagnosed with inflammatory bowel disease, psoriasis, psoriatic arthritis, ankylosing spondylitis, or rheumatoid arthritis exhibited greater waning of Ab and T cell responses than healthy control subjects after SARS-CoV-2 vaccine dose 2. Fewer data are available on the effects of third and fourth doses. This observational cohort study collected plasma and PBMCs from healthy control subjects and untreated or treated patients with IMIDs prevaccination and after one to four doses of SARS-CoV-2 mRNA vaccine (BNT162b2 or mRNA-1273). SARS-CoV-2-specific Ab levels, neutralization, and T cell cytokine release were measured against wild-type and Omicron BA.1 and BA.5 variants of concern. Third vaccine doses substantially restored and prolonged Ab and T cell responses in patients with IMIDs and broadened responses against variants of concern. Fourth-dose effects were subtle but also prolonged Ab responses. However, patients with IMIDs treated with anti-TNF, especially patients with inflammatory bowel disease, exhibited lower Ab responses even after the fourth dose. Although T cell IFN-γ responses were maximal after one dose, IL-2 and IL-4 production increased with successive doses, and early production of these cytokines was predictive of neutralization responses at 3-4 mo postvaccination. Our study demonstrates that third and fourth doses of the SARS-CoV-2 mRNA vaccines sustain and broaden immune responses to SARS-CoV-2, supporting the recommendation for three- and four-dose vaccination regimens in patients with IMIDs.

The intersection of biological sex and gender in adverse events following seasonal influenza vaccination in older adults

Background Women/females report more adverse events (AE) following immunization than men/males for many vaccines, including the influenza and COVID-19 vaccines. This discrepancy is often dismissed as a reporting bias, yet the relative contributions of biological sex and gender are poorly understood. We investigated the roles of sex and gender in the rate of AE following administration of the high-dose seasonal influenza vaccine to older adults (≥ 75 years) using an AE questionnaire administered 5-8 days post-vaccination. Participant sex (male or female) was determined by self-report and a gender score questionnaire was used to assign participants to one of four gender categories (feminine, masculine, androgynous, or undifferentiated). Sex steroid hormones and inflammatory cytokines were measured in plasma samples collected prior to vaccination to elucidate a possible biological mechanism for the AE reported. Results A total of 423 vaccines were administered to 173 participants over four influenza seasons (2019-22) and gender data were available for 339 of these vaccinations (2020-22). At least one AE was reported following 105 vaccinations (25%), by 23 males and 82 females. The majority of AE occurred at the site of injection, were mild, and transient. The odds of experiencing an AE were 3-fold greater in females than males and decreased with age to a greater extent in females than males. The effects of gender, however, were not statistically significant, supporting a central role of biological sex in the occurrence of AE. In males, estradiol was significantly associated with IL-6 and with the probability of experiencing an AE. Both associations were absent in females, suggesting a sex-specific effect of estradiol on the occurrence of AE that supports the finding of a biological sex difference. Conclusions These data support a larger role for biological sex than for gender in the occurrence of AE following influenza vaccination in older adults and provide an initial investigation of hormonal mechanisms that may mediate this sex difference. This study highlights the complexities of measuring gender and the importance of assessing AE separately for males and females to better understand how vaccination strategies can be tailored to different subsets of the population.

Transfusing Convalescent Plasma as Post-Exposure Prophylaxis Against Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Infection: A Double-Blinded, Phase 2 Randomized, Controlled Trial

BACKGROUND

The efficacy of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) convalescent plasma (CCP) for preventing infection in exposed, uninfected individuals is unknown. CCP might prevent infection when administered before symptoms or laboratory evidence of infection.

METHODS

This double-blinded, phase 2 randomized, controlled trial (RCT) compared the efficacy and safety of prophylactic high titer (≥1:320 by Euroimmun ELISA) CCP with standard plasma. Asymptomatic participants aged ≥18 years with close contact exposure to a person with confirmed coronavirus disease 2019 (COVID-19) in the previous 120 hours and negative SARS-CoV-2 test within 24 hours before transfusion were eligible. The primary outcome was new SARS-CoV-2 infection.

RESULTS

In total, 180 participants were enrolled; 87 were assigned to CCP and 93 to control plasma, and 170 transfused at 19 sites across the United States from June 2020 to March 2021. Two were excluded for screening SARS-CoV-2 reverse transcription polymerase chain reaction (RT-PCR) positivity. Of the remaining 168 participants, 12/81 (14.8%) CCP and 13/87 (14.9%) control recipients developed SARS-CoV-2 infection; 6 (7.4%) CCP and 7 (8%) control recipients developed COVID-19 (infection with symptoms). There were no COVID-19-related hospitalizations in CCP and 2 in control recipients. Efficacy by restricted mean infection free time (RMIFT) by 28 days for all SARS-CoV-2 infections (25.3 vs 25.2 days; P = .49) and COVID-19 (26.3 vs 25.9 days; P = .35) was similar for both groups.

CONCLUSIONS

Administration of high-titer CCP as post-exposure prophylaxis, although appearing safe, did not prevent SARS-CoV-2 infection.

CLINICAL TRIALS REGISTRATION

NCT04323800.

The intersection of gender and race in older adults' decision to receive COVID-19 vaccines

COVID-19 vaccines are essential public health tools for protecting older adults, who are at high risk of severe outcomes associated with COVID-19. Little is known, however, about how older adults approach the decision to receive a COVID-19 vaccine. We hypothesized that intersections between gender and race may provide unique insight into the decision-making process and the factors that lead to vaccine uptake among hesitant individuals. We performed in-depth interviews with 24 older adults who had been vaccinated against COVID-19 and used the framework approach with an intersectional lens to analyze data. Two typologies emerged: eager compliers did not question the need to vaccinate, whereas hesitant compliers were skeptical of the vaccine and underwent a thorough decision-making process prior to vaccination. For eager compliers, the vaccine offered protection from a disease that posed a serious threat, and few risks were perceived. In contrast, hesitant compliers perceived risks associated with the vaccine product or mistrusted the infrastructure that led to rapid vaccine development. Hesitancy was greater among Black participants, and only Black participants reported mistrust in vaccine infrastructure. At the intersection of gender and race, a 'White male effect' was observed, whereby White men perceived the fewest risks associated with the vaccine, and Black women were the most fearful of serious side effects. Nearly all hesitant compliers ultimately got vaccinated due to the threat of COVID-19. Convenient access through vaccine clinics in senior's buildings was pivotal for hesitant compliers and external and internal influences had differential impacts by race and gender. Emphasizing the risk of COVID-19, convenient and accessible opportunities for vaccination, and messages that are targeted to specific groups are likely to increase vaccine uptake among older adults.

Effects of Biological Sex and Pregnancy on SARS-CoV-2 Pathogenesis and Vaccine Outcomes

SARS-CoV-2 is the causative agent of COVID-19 in humans and has resulted in the death of millions of people worldwide. Similar numbers of infections have been documented in males and females; males, however, are more likely than females to be hospitalized, require intensive care unit, or die from COVID-19. The mechanisms that account for this are multi-factorial and are likely to include differential expression of ACE2 and TMPRSS2 molecules that are required for viral entry into hosts cells and sex differences in the immune response, which are due to modulation of cellular functions by sex hormones and differences in chromosomal gene expression. Furthermore, as comorbidities are also associated with poorer outcomes to SARS-CoV-2 infection and several comorbidities are overrepresented in males, these are also likely to contribute to the observed sex differences. Despite their relative better prognosis following infection with SARS-CoV-2, females do have poorer outcomes during pregnancy. This is likely to be due to pregnancy-induced changes in the immune system that adversely affect viral immunity and disruption of the renin-angiotensin system. Importantly, vaccination reduces the severity of disease in males and females, including pregnant females, and there is no evidence that vaccination has any adverse effects on the outcomes of pregnancy.

Association of Frailty, Age, and Biological Sex With Severe Acute Respiratory Syndrome Coronavirus 2 Messenger RNA Vaccine-Induced Immunity in Older Adults

BACKGROUND

Male sex and old age are risk factors for severe coronavirus disease 2019, but the intersection of sex and aging on antibody responses to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines has not been characterized.

METHODS

Plasma samples were collected from older adults (aged 75-98 years) before and after 3 doses of SARS-CoV-2 mRNA vaccination, and from younger adults (aged 18-74 years) post-dose 2, for comparison. Antibody binding to SARS-CoV-2 antigens (spike protein [S], S receptor-binding domain, and nucleocapsid), functional activity against S, and live-virus neutralization were measured against the vaccine virus and the Alpha, Delta, and Omicron variants of concern (VOCs).

RESULTS

Vaccination induced greater antibody titers in older females than in older males, with both age and frailty associated with reduced antibody responses in males but not females. Responses declined significantly in the 6 months after the second dose. The third dose restored functional antibody responses and eliminated disparities caused by sex, age, and frailty in older adults. Responses to the VOCs, particularly the Omicron variant, were significantly reduced relative to the vaccine virus, with older males having lower titers to the VOCs than older females. Older adults had lower responses to the vaccine and VOC viruses than younger adults, with greater disparities in males than in females.

CONCLUSIONS

Older and frail males may be more vulnerable to breakthrough infections owing to low antibody responses before receipt of a third vaccine dose. Promoting third dose coverage in older adults, especially males, is crucial to protecting this vulnerable population.

Sex-specific effects of age and body mass index on antibody responses to seasonal influenza vaccines in healthcare workers

Healthcare institutions with mandatory influenza vaccination policies have over 90% vaccination rates among healthcare workers (HCWs) resulting in a population that has received the influenza vaccine in many, consecutive years. This study explored the impact of sex and other host factors in pre- and post-vaccination neutralizing antibody (nAb) titers and seroconversion against the H1N1 and H3N2 influenza A viruses (IAVs) among HCWs enrolled into a cross-sectional serosurvey during the annual Johns Hopkins Hospital employee vaccination campaign in the 2017-18 and 2018-19 seasons. The study enrolled 111 participants (male = 38, female = 73) in 2017-18 and 163 (male = 44, female = 119) in 2018-19. Serum samples were collected immediately prior to vaccination and approximately 28 days later and nAb titers to vaccine strains determined. An intersectional approach was used to disaggregate the combined effects of sex with age and body mass index (BMI) in the nAb response. Differences between the pre- or post-vaccination geometric mean nAb titers between male and female HCWs were not observed. Male HCWs were 2.86 times more likely to seroconvert compared to female HCWs in 2017-2018, but the same trend was not observed in the following year. When data were disaggregated by age and sex, older female HCWs had higher H1N1 pre- and post-vaccination nAb titers compared to male HCWs in the same age group for both vaccination campaign seasons. In both years, the decline in H3N2 pre-vaccination titers with increasing BMI was greater in female than male HCW. The sex-specific effects of age and BMI on nAb responses to seasonal influenza vaccines require greater consideration.

Adaptive immune responses in vaccinated patients with symptomatic SARS-CoV-2 Alpha infection

Benchmarks for protective immunity from infection or severe disease after SARS-CoV-2 vaccination are still being defined. Here, we characterized virus neutralizing and ELISA antibody levels, cellular immune responses, and viral variants in 4 separate groups: healthy controls (HCs) weeks (early) or months (late) following vaccination in comparison with symptomatic patients with SARS-CoV-2 after partial or full mRNA vaccination. During the period of the study, most symptomatic breakthrough infections were caused by the SARS-CoV-2 Alpha variant. Neutralizing antibody levels in the HCs were sustained over time against the vaccine parent virus but decreased against the Alpha variant, whereas IgG titers and T cell responses against the parent virus and Alpha variant declined over time. Both partially and fully vaccinated patients with symptomatic infections had lower virus neutralizing antibody levels against the parent virus than the HCs, similar IgG antibody titers, and similar virus-specific T cell responses measured by IFN-γ. Compared with HCs, neutralization activity against the Alpha variant was lower in the partially vaccinated infected patients and tended to be lower in the fully vaccinated infected patients. In this cohort of breakthrough infections, parent virus neutralization was the superior predictor of breakthrough infections with the Alpha variant of SARS-CoV-2.

Roadmap for Sex-Responsive Influenza and COVID-19 Vaccine Research in Older Adults

Sex differences in the immune system are dynamic throughout the lifespan and contribute to heterogeneity in the risk of infectious diseases and the response to vaccination in older adults. The importance of the intersection between sex and age in immunity to viral respiratory diseases is clearly demonstrated by the increased prevalence and severity of influenza and COVID-19 in older males compared to older females. Despite sex and age biases in the epidemiology and clinical manifestations of disease, these host factors are often ignored in vaccine research. Here, we review sex differences in the immunogenicity, effectiveness, and safety of the influenza and COVID-19 vaccines in older adults and the impact of sex-specific effects of age-related factors, including chronological age, frailty, and the presence of comorbidities. While a female bias in immunity to influenza vaccines has been consistently reported, understanding of sex differences in the response to COVID-19 vaccines in older adults is incomplete due to small sample sizes and failure to disaggregate clinical trial data by both sex and age. For both vaccines, a major gap in the literature is apparent, whereby very few studies investigate sex-specific effects of aging, frailty, or multimorbidity. By providing a roadmap for sex-responsive vaccine research, beyond influenza and COVID-19, we can leverage the heterogeneity in immunity among older adults to provide better protection against vaccine-preventable diseases.

Randomized controlled trial transfusing convalescent plasma as post-exposure prophylaxis against SARS-CoV-2 infection

BACKGROUND

The efficacy of SARS-CoV-2 convalescent plasma (CCP) for preventing infection in exposed, uninfected individuals is unknown. We hypothesized that CCP might prevent infection when administered before symptoms or laboratory evidence of infection.

METHODS

This double-blinded, phase 2 randomized, controlled trial (RCT) compared the efficacy and safety of prophylactic high titer (≥1:320) CCP with standard plasma. Asymptomatic participants aged ≥18 years with close contact exposure to a person with confirmed COVID-19 in the previous 120 hours and negative SARS-CoV-2 test within 24 hours before transfusion were eligible. The primary outcome was development of SARS-CoV-2 infection.

RESULTS

180 participants were enrolled; 87 were assigned to CCP and 93 to control plasma, and 170 transfused at 19 sites across the United States from June 2020 to March 2021. Two were excluded for SARS-CoV-2 RT-PCR positivity at screening. Of the remaining 168 participants, 12/81 (14.8%) CCP and 13/87 (14.9%) control recipients developed SARS-CoV-2 infection; 6 (7.4%) CCP and 7 (8%) control recipients developed COVID-19 (infection with symptoms). There were no COVID-19-related hospitalizations in CCP and 2 in control recipients. There were 28 adverse events in CCP and 58 in control recipients. Efficacy by restricted mean infection free time (RMIFT) by 28 days for all SARS-CoV-2 infections (25.3 vs. 25.2 days; p=0.49) and COVID-19 (26.3 vs. 25.9 days; p=0.35) were similar for both groups.

CONCLUSION

In this trial, which enrolled persons with recent exposure to a person with confirmed COVID-19, high titer CCP as post-exposure prophylaxis appeared safe, but did not prevent SARS-CoV-2 infection.

TRIAL REGISTRATION

Clinicaltrial.gov number NCT04323800 .

Sex-specific effects of aging on humoral immune responses to repeated influenza vaccination in older adults

Older adults (≥65 years of age) bear a significant burden of severe disease and mortality associated with influenza, despite relatively high annual vaccination coverage and substantial pre-existing immunity to influenza. To test the hypothesis that host factors, including age and sex, play a role in determining the effect of repeated vaccination and levels of pre-existing humoral immunity to influenza, we evaluated pre- and post-vaccination strain-specific hemagglutination inhibition (HAI) titers in adults over 75 years of age who received a high-dose influenza vaccine in at least four out of six influenza seasons. Pre-vaccination titers, rather than host factors and repeated vaccination were significantly associated with post-vaccination HAI titer outcomes, and displayed an age-by-sex interaction. Pre-vaccination titers to H1N1 remained constant with age. Titers to H3N2 and influenza B viruses decreased substantially with age in males, whereas titers in females remained constant with age. Our findings highlight the importance of pre-existing immunity in this highly vaccinated older adult population and suggest that older males are particularly vulnerable to reduced pre-existing humoral immunity to influenza.

Beyond a Zero-Sum Game: How Does the Impact of COVID-19 Vary by Gender?

Epidemics and pandemics, like COVID-19, are not gender neutral. Much of the current work on gender, sex, and COVID-19, however, has seemed implicitly or explicitly to be attempting to demonstrate that either men or women have been hardest hit, treating differences between women and men as though it is not important to understand how each group is affected by the virus. This approach often leaves out the effect on gender and sexual minorities entirely. Believing that a more nuanced approach is needed now and for the future, we brought together a group of gender experts to answer the question: how are people of different genders impacted by COVID-19 and why? Individuals working in women's, men's, and LGBTQ health and wellbeing wrote sections to lay out the different ways that women, men, and gender and sexual minorities are affected by COVID-19. We demonstrate that there is not one group "most affected," but that many groups are affected, and we need to move beyond a zero-sum game and engage in ways to mutually identify and support marginalized groups.

Sex, age, and hospitalization drive antibody responses in a COVID-19 convalescent plasma donor population

Convalescent plasma is a leading treatment for coronavirus disease 2019 (COVID-19), but there is a paucity of data identifying its therapeutic efficacy. Among 126 potential convalescent plasma donors, the humoral immune response was evaluated using a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus neutralization assay with Vero-E6-TMPRSS2 cells; a commercial IgG and IgA ELISA to detect the spike (S) protein S1 domain (EUROIMMUN); IgA, IgG, and IgM indirect ELISAs to detect the full-length S protein or S receptor-binding domain (S-RBD); and an IgG avidity assay. We used multiple linear regression and predictive models to assess the correlations between antibody responses and demographic and clinical characteristics. IgG titers were greater than either IgM or IgA titers for S1, full-length S, and S-RBD in the overall population. Of the 126 plasma samples, 101 (80%) had detectable neutralizing antibody (nAb) titers. Using nAb titers as the reference, the IgG ELISAs confirmed 95%-98% of the nAb-positive samples, but 20%-32% of the nAb-negative samples were still IgG ELISA positive. Male sex, older age, and hospitalization for COVID-19 were associated with increased antibody responses across the serological assays. There was substantial heterogeneity in the antibody response among potential convalescent plasma donors, but sex, age, and hospitalization emerged as factors that can be used to identify individuals with a high likelihood of having strong antiviral antibody responses.

Sex-biased Immune Responses Following SARS-CoV-2 Infection

Males are disproportionately affected by severe disease and death from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. In their recent article, Takahashi et al. found sex differences in immune responses to SARS-CoV-2 and the predictors of disease progression. These findings contribute to elucidating the mechanisms that underlie the male bias in severe disease and death from coronavirus disease 2019 (COVID-19).

Cesarean delivery is not associated with decreased at-birth fracture rates in osteogenesis imperfecta

Purpose

Osteogenesis imperfecta (OI) predisposes to recurrent fractures. The moderate-to-severe forms of OI present with antenatal fractures and the mode of delivery that would be safest for the fetus is not known.

Methods

We conducted systematic analyses on the largest cohort of individuals (n=540) with OI enrolled to-date in the OI Linked Clinical Research Centers. Self-reported at-birth fracture rates were compared in individuals with OI types I, III, and IV. Multivariate analyses utilizing backward-elimination logistic regression model building were performed to assess the effect of multiple covariates including method of delivery on fracture-related outcomes.

Results

When accounting for other covariates, at-birth fracture rates did not differ based on whether delivery was by vaginal route or by cesarean section (CS). Increased birth weight conferred higher risk for fractures irrespective of the delivery method. In utero fracture, maternal history of OI, and breech presentation were strong predictors for choosing CS for delivery.

Conclusion

Our study, the largest to analyze the effect of various factors on at-birth fracture rates in OI shows that delivery by CS is not associated with decreased fracture rate. With the limitation that the fracture data were self-reported in this cohort, these results suggest that CS should be performed only for other maternal or fetal indications, but not for the sole purpose of fracture prevention in OI.

A cross-sectional multicenter study of osteogenesis imperfecta in North America - results from the linked clinical research centers

Osteogenesis imperfecta (OI) is the most common skeletal dysplasia that predisposes to recurrent fractures and bone deformities. In spite of significant advances in understanding the genetic basis of OI, there have been no large-scale natural history studies. To better understand the natural history and improve the care of patients, a network of Linked Clinical Research Centers (LCRC) was established. Subjects with OI were enrolled in a longitudinal study, and in this report, we present cross-sectional data on the largest cohort of OI subjects (n = 544). OI type III subjects had higher prevalence of dentinogenesis imperfecta, severe scoliosis, and long bone deformities as compared to those with OI types I and IV. Whereas the mean lumbar spine area bone mineral density (LS aBMD) was low across all OI subtypes, those with more severe forms had lower bone mass. Molecular testing may help predict the subtype in type I collagen-related OI. Analysis of such well-collected and unbiased data in OI can not only help answering questions that are relevant to patient care but also foster hypothesis-driven research, especially in the context of 'phenotypic expansion' driven by next-generation sequencing.

Osteogenesis imperfecta: effecting the transition from adolescent to adult medical care

The objective of this paper is to provide guidelines for pediatricians, adult physicians in different medical disciplines and patients' families who are planning the transition to adult care for the adolescent with osteogenesis imperfecta (OI). This observational report reflects concerns expressed by patients, their families, and involved physicians regarding the problems encountered with the transition of care. Methods for dealing with transitional issues are presented. OI is a heritable disorder of connective tissue in which fractures are the dominant clinical feature. However, OI is a systemic disorder with broad clinical variability in which there are unpredictable episodes of trauma. Coordinated team support provides the best level of care for the child with OI. This paper discusses 4 key topics related to effecting the transition from pediatric to adult care: 1) Transitioning and maintaining health, 2) Preserving or improving the level of function, 3) Assuring continuity of medical/surgical care, and 4) Re-structuring psychosocial and work-related systems. The process of transition requires active communication between the pediatric and adult team members along with a proactive approach by the patient and family. In addition, as the transition is established, the patient with OI should be encouraged to be his/her own advocate and care coordinator.

Perception of teasing in underweight persons: a modification of the perception of teasing scale

The psychometric properties of the Perception of Teasing Scale-Underweight, a modified version of the Perception of Teasing Scale (1), were examined. One hundred eighty-three college students (81 male; 102 female; age range 17-57 years) completed questionnaires about underweight-related and competency-related teasing experiences, eating attitudes, body image, self-esteem, and mood. Factor analysis suggested the Perception of Teasing Scale-Underweight has a two-factor structure, measuring both underweight-related and competency-related teasing experiences. Significant correlations (p<0.05) were found between the Perception of Teasing Scale-Underweight, Beck Depression Inventory, Fear of Negative Appearance Evaluation Scale, Multidimentional Body-Self Relations Questionnaire-Appearance Scales, Multiaxial Eating Disorder Scale, Social Physique Anxiety Scale, and Rosenberg Self-Esteem Scale. The pattern of correlations differed between the entire sample and those with a body mass index <21. One-way analysis of variance analyses found significant differences (p<0.05) between those with body mass index (BMI) <21 and those with BMI >21 for the weight-related event and weight-related impact scales, indicating that the measure discriminates between those individuals most likely to have been underweight as adolescents versus those most likely to have been normal weight or overweight. This measure provides a sound psychometric tool for examining underweight-related and competency-related teasing experiences. The impact of appearance and competence related teasing in underweight persons is less well understood than in overweight samples; therefore, future work should be conducted with a more underweight sample to bridge this gap in the literature.

The effect of intravenous pamidronate on bone mineral density, bone histomorphometry, and parameters of bone turnover in adults with type IA osteogenesis imperfecta

The type IA osteogenesis imperfecta (OI) phenotype is characterized by multiple fractures, blue sclerae, and minimal skeletal deformity without dentinogenesis imperfecta. The object of this study was to determine the effect of treatment with intravenous pamidronate (30 mg) every 3 months on bone density and bone histomorphometry in adults with type IA OI. After an initial iliac crest bone biopsy eight subjects, 5 women and 3 men, entered a treatment program lasting 21-30 months. Five subjects, all women, completed the study which included a posttreatment iliac crest bone biopsy. Pamidronate treatment led to significant increases in bone mineral density (BMD), measured by DXA, in the lumbar spine at 12 months (P = 0.05) and in the femur neck (P = 0.02) at 24 months. Significant increases in BMD were also seen in femoral trochanter at 12 months (P = 0.05) and at 24 months (P = 0.02), and in Ward's triangle at 12 months (P = 0.02) and 24 months (P = 0.05). Mean osteocalcin levels decreased 32%, C-terminal procollagen peptide and bone alkaline phosphatase declined 12% and 47% at 15 and 21 months, respectively. Deoxypyridinoline crosslink excretion decreased 31%. Posttreatment bone biopsy revealed a significant 6.3% increase in mean bone trabecular volume (P = 0.01). Mean cortical thickness increased from 848 mm to 1384 mm (P = 0.01) and cortical porosity decreased 13.2% (P = 0.01). Bone formation rate increased significantly in all 5 patients from 6.6 to 15.3 mm2/yr (P = 0.01). Mineral apposition rate was unchanged. These results indicate that intravenous pamidronate, 30 mg every 3 months, may have significant effects on bone density and histomorphometry in adults with type IA OI. Responses at higher doses remain to be evaluated.

Disease management: what have we learned so far?

Disease management (DM) is becoming an increasingly important tool for use in end-stage renal disease (ESRD). The goal of a DM program is to offer a continuum of care that uses guidelines and case management protocols to prevent acute care episodes, achieve improved outcomes and reduce health care costs. This article reviews the theory behind DM, describes key components of DM programs and explains the financial incentives for DM in ESRD. Of key importance in the increasing role of DM for ESRD has been the development of nationally recognized guidelines, the effects of which are now beginning to emerge. At the same time, recent studies have identified targeted opportunities for DM programs to improve outcomes and costs, including anemia management, dialysis dose, and vascular access. DM, through the use of guidelines and targeted toward these and other areas, has the potential to significantly impact the quality of care provided to ESRD patients.

Genetics of nervous system tumors

Genetic aberrations are being defined for the various glial tumors. Astrocytic tumors can evolve by two different pathways. The genetic aberrations now being defined for these two pathways are different and can be associated with the grade of malignancy. In oligodendrogliomas, the genetic lesions differ from the astrocytic tumors, and several markers have been linked to chemosensitivity response and survival. Genetic aberrations in ependymomas also differ from the astrocytic tumors or oligodendrogliomas. Although additional cases are needed to study the genetic aberrations, the abnormalities identified suggest that spinal cord tumors carry different markers than intracranial tumors and that the markers within the cranium may be different based on their location.

Hemodynamic effects of chest closure in adult patients undergoing cardiac surgery

OBJECTIVE

To evaluate hemodynamic effects of sternal retractor removal and sternal closure after cardiopulmonary bypass and to correlate these changes with preoperative and intraoperative variables.

DESIGN

Prospective.

SETTING

University hospital.

PARTICIPANTS

Fifty adults undergoing cardiac surgery.

MEASUREMENTS AND MAIN RESULTS

Arterial, pulmonary artery, and transesophageal echocardiography measurements were obtained immediately before and 1 minute after removal of the sternal retractor and immediately before and 1 minute after sternal closure. Retractor removal caused a significant decrease in cardiac index by 5.6% (p < 0.01), stroke volume index by 4.0% (p < 0.05), and mean pulmonary artery pressure by 4.8% (p < 0.001). Sternal closure caused a significant decrease in cardiac index by 7.7%, stroke volume index by 10.2%, and left ventricular end-diastolic area by 9.2% (p < 0.001) There were significant increases in pulmonary capillary wedge pressure and systemic vascular resistance by 9.1% and 10.8% (p < 0.01). There was no significant change in the ejection fraction area. The magnitude of decrease in stroke volume index with sternal closure correlated positively with end-diastolic area immediately before the closure.

CONCLUSION

Chest closure is associated with significant hemodynamic changes and a change in the ventricular transmural pressure-volume relationship. Patients with lower preload immediately before closure are more vulnerable to a decrease in cardiac index. Based on the results of this study, volume appears to be the appropriate preventive and treatment option to limit the impact of chest closure.

Genetics of brain neoplasms

Transformation of a normal cell into a malignant cell involves a series of events that damage the genome. Gliomas are the most common adult neoplasm of the central nervous system. To develop new therapeutic strategies requires an understanding of the specific lesions that occur and contribute to this malignant process. Initially, data reported from the analyses of human gliomas were quite variable. This has recently changed as more data have become available and the selection of tissue analyzed is coupled with clinical criteria. Specific genetic lesions are now defining different glioma pathways, and some aberrations may be indicative of therapeutic response. This review focuses on the specific genetic aberrations associated with astrocytic and oligodenroglial tumors.

Altered nuclear localization of bax protein in BCNU-resistant glioma cells

To investigate the role of apoptosis suppression in glioma chemotherapy resistance, protein levels and subcellular localization of bcl-2 family members were investigated in 2 pairs of sensitive cell lines and their in vitro generated resistant derivatives. The alkylating agent, 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU), induced apoptosis in both sensitive cell strains and apoptosis was suppressed in both resistant derivatives. Both resistant cell lines contained altered regulation of a bcl-2 related protein consistent with the suppression of apoptosis. Independent of which bcl-2 family member was dysregulated, resistance was associated with altered regulation in the subcellular localization of bax protein. Following BCNU treatment, bax accumulated in nucleoli and a nuclei containing fraction of sensitive cells but not their resistant derivatives. Nuclear accumulation was an early event in apoptosis induction. These data indicates altered subcellular localization of bax may play a role in resistance. In addition, the association between an early, nucleolar localization of bax and the induction of apoptosis suggests that localization of bax to nucleoli may play a role in apoptosis-induction of glioma cells.

Disuse bone loss in hindquarter suspended rats: partial weightbearing, exercise and ibandronate treatment as countermeasures

The purpose of this study was to evaluate potential countermeasures for bone loss during long-term space missions in the hindquarter suspended rat, including partial weight bearing (surrogate for artificial gravity) episodic full weight bearing (2 hour/day full weight bearing) and treatment with the third generation bisphosphonate ibandronate (Roche). Graded mechanical loading was studied by housing the animals on a novel servo controlled force plate system which permitted the titration of mechanical force at varying frequency and amplitude and different levels of weight bearing. The force plate, which forms the cage floor, is a glass platform supported by an 18" diameter speaker cone filled with expanding polyurethane foam. An infrared optical sensor attached to the speaker cone yields a voltage linearly related to vertical displacement of the glass platform. The dynamic force on the paw was computed as a product of the apparent mass of the animal on the platform at rest and the acceleration of the platform determined from the second derivative of the optical sensor output. The mass of the animal on the platform was varied by adjusting tension on the tether suspending the animal. Mechanical impact loading was titrated with the force plate resonating at different frequencies, including 3 Hz and 16 Hz.

Countermeasure development: future research targets

We will briefly discuss a series of countermeasures that are currently being developed to maintain bone mass and the integrity of supporting connective tissues. Our objective is to focus on several countermeasures under development which can be tested on the ISS. Other countermeasures may also be needed to provide additional safety factors which are required before long duration spaceflight is undertaken.

Rehabilitative care of war-related health concerns

The objective of this study was to pilot the effectiveness of a 3-week rehabilitative intervention that used medical review, graded exercise, education on Gulf War exposures, active coping, and nutrition to improve disability and related distress for Gulf War veterans with persistent symptoms. One hundred and nine veterans were assessed at program entry and exit and at 1 and 3 months after program completion. Outcomes were physical symptoms, quality of life, physical health concern, and psychosocial distress--contrasted across time and demographic groups. After treatment, veterans showed modest and global improvements; women were more likely than men to show improvement. The finding that Gulf War veterans who completed specialized rehabilitative management experienced modest, short-term improvements is encouraging, given that veterans of the conflict remain concerned about their future health. Controlled studies are needed.

The role of respiratory care practitioners in a changing healthcare system: emerging areas of clinical practice

OBJECTIVE

To evaluate shifts in respiratory care practice in the context of changing healthcare system and market dynamics.

STUDY DESIGN

Telephone survey, structured interview, and case studies.

METHODS

We conducted a telephone survey of 471 respiratory care practitioners (RCPs), drawn from the membership database of the American Association for Respiratory Care. We also interviewed 10 employers of RCPs and conducted 2 in-depth case studies to supplement our survey results. We used several statistical techniques to analyze our data, including calculation of population-weighted descriptive statistics and multivariate regression models.

RESULTS

Changes in the healthcare system have prompted RCPs to broaden their practice settings, skills, and responsibilities. Respiratory care practitioners are taking part in managed care-related activities, such as cost control and disease management. We found that the need for certain skills and responsibilities varies by practice setting. In our interviews, employers considered RCPs cost effective providers for certain services.

CONCLUSIONS

The practice of respiratory care is evolving to meet the changing needs of the healthcare system. A key challenge is to ensure appropriate growth and development of the respiratory care profession, as well as the delivery of appropriate services under new care management settings and processes.

Allogeneic astrocytoma in immune competent dogs

We have induced in canines long-term immune tolerance to an allogeneic cell line derived from a spontaneous canine astrocytoma. Allogeneic astrocytoma cells were implanted endoscopically into the subcutaneous space of fetal dogs before the onset of immune competency (< 40th gestational day). At adulthood, dogs rendered tolerant successfully serve as recipients of intracranial transplants of their growing allogeneic, subcutaneous tumor. Transplanted dogs subsequently develop a solid brain tumor with histological features similar to the original astrocytoma. This model may allow rapid development and evaluation of new therapies for brain tumors, as well as afford tumor biology studies that are untenable in smaller, immune incompetent, or inbred animals harboring less representative tumors.

Calvarial doughnut lesions associated with high-turnover osteoporosis presenting in childhood

Osteogenesis imperfecta and juvenile osteoporosis are two well-described syndromes of osteoporosis presenting in childhood. There are also several references in the radiology literature to calvarial doughnut lesions (CDLs), areas of radiolucency surrounded by a dense and well-defined area of sclerotic bone, either as an incidental finding or associated with childhood fracture. We have characterized the metabolic abnormalities in a 13-yr-old boy with CDLs and multiple fractures and followed him during his progression through puberty. The patient's paternal grandmother; father; and paternal aunt, uncle, and first cousin were similarly affected, and a mandibular lesion in the uncle was pathologically described as fibrous dysplasia. The subject's physical examination was significant for bony protuberances of the skull and normal hearing, sclearal hue, dentition, and joint flexibility. Radiographs revealed calvarial CDLs and osteopenia which was confirmed by bone mineral density (BMD) testing. Biochemical markers of bone formation and resorption were elevated compared to normal adult and a transiliac crest bone biopsy confirmed high-turnover osteoporosis. Over 6 yr, with no specific therapy, BMD gradually normalized, but the CDLs increased in size, bone turnover remained elevated by biochemical markers, and he continued to fracture. The subject's affected father and maternal grandmother had normal BMD and no history of adult fracture. CDLs with high-turnover osteoporosis should be considered in the differential diagnosis of pediatric osteoporosis. During puberty the BMD normalizes but the high-turnover state persists, and the propensity to fracture eventually decreases in older affected adults. The CDLs may be a variant of fibrous dysplasia, and further study is necessary in order to elucidate the stimulus for increased bone turnover and the familial nature of this syndrome.

Paget's disease of bone (osteitis deformans)

Paget's disease of bone is important in geriatric populations because it is the second most common bone disorder after osteoporosis. In older people, it may be responsible for chronic back pain and joint pain, skeletal deformities, hearing loss, and cranial nerve compression. Paget's disease can reduce both function and mobility in the older people. In addition to newer tests for assessing the activity of Paget's disease, effective therapy is available in the form of salmon calcitonin for nasal administration and new third generation bisphosphonates. Frequently, treatment can reverse the course of the disease. For these reasons, it is feasible for the physician to adopt an aggressive approach to diagnosis and treatment. The objective should be to relieve pain, improve mobility, and forestall debilitating complications. This review will focus on the manifestations and clinical management of Paget's disease. Two cases are presented that illustrate common management problems in older patients.

Age-related changes in human oestrogen receptor alpha function and levels in osteoblasts

Oestrogen receptors (ERs) are present in human osteoblasts and mediate anti-resorptive effects on bone. Human osteoblast-like cells derived from different aged healthy female donors not on hormone replacement therapy were utilized under well-defined conditions in vitro to investigate ER function and levels. Treatment with 0.1 nM oestradiol-17beta of cell strains derived from eight young women (less than 50 years of age) increased hydroxyproline levels significantly [an average (2.2+/-0.1 S.E.M.)-fold increase], whereas cells derived from nine older women (more than 50 years of age) were not significantly affected. Similarly, cell strains, derived from younger women, transfected with a consensus oestrogen-responsive element linked to chloramphenicol acetyltransferase exhibited a greater response to oestrogen than strains derived from older women. When basal ERalpha levels were measured by enzyme immunoassay and normalized on a per cell basis, osteoblast-like strains derived from younger women (n=24) had a mean value of 2.54+/-0.16 fmol of ERalpha per 10(6) cells. In contrast, strains derived from older women (n=20) had a mean value of 5.44+/-0.48 fmol of ERalpha per 10(6) cells. An age-related increase in ERalpha number was also observed in human skin-derived fibroblasts and directly in dermal biopsies from women not on hormone replacement therapy. The results demonstrate ligand concentration-dependent ERalpha induction and indicate a loss of receptor regulation and diminution of ligand-receptor signal transduction with increasing donor age.

Bone geometry and strength measurements in aging mice with the oim mutation

Mice with the naturally occurring oim mutation allows investigation of bone pathobiology in the setting of one mutation: a G deletion in the murine Cola-2 gene (exon 52) encoding the proalpha2(I) C-propeptide. As a result, normal sized mRNA is transcribed, but no secreted protein has been identified in oim/oim fibroblasts or osteoblasts. Here we report longitudinal changes in body mass, bone geometry, and bone structural properties of femurs tested in torsion from wild type (+/+) mice and mice homozygous (oim/oim) and heterozygous (+/oim) for the oim mutation. Femurs from mice 3 months, 6 months, 12 months, and >18 months of age were dissected and X-ray films were taken in anterioposterior and mediolateral views to estimate the geometric properties. The metaphyseal ends of femurs were potted in polymethylemethacrylate and mounted on a torsional test fixture designed to convert axial tensile deformation to a torsional load using an INSTRON model 4204 materials tester. Compared with +/+ samples, peak torque at failure was reduced in oim/oim mice. Also, the geometric distribution of midshaft bone for oim/oim mice in terms of cortical area and polar moment was significantly reduced. However, the impact of the mutation on bone distribution was relatively minor for +/oim mice. Consistent with a type III classification in human OI patients, the presence of two nonfunctional alleles in homozygous oim mice significantly reduced body mass compared with age-matched wild type mice. However, no statistical difference in body mass was detected between +/oim and +/+ mice. The absence of a gross phenotypic difference between +/oim and +/+ mice demonstrates a milder phenotype in +/oim mice.

Biology and treatment of malignant glioma

A large number of oncogenes have been identified as aberrant in gliomas, but only the erbB oncogene (gene encoding the epidermal growth factor receptor [EGFR]) is amplified in an appreciable number. The loss or mutation of tumor-suppressor genes located on different autosomes may be associated with progression of malignant gliomas. The p53 tumor-suppressor gene (located on chromosome 17) is frequently associated with the loss of one allele in malignant gliomas, although a large number of malignant gliomas have no p53 mutations. Some of the latter tumors have an amplified murine double minute 2 (MDM2) gene, which suppresses p53 gene activity. Genetic material from chromosome 10 may also be lost, especially in glioblastoma multiforme. In addition to the aberrant expression of EGFR, another growth factor, platelet-derived growth factor, or PDGF (ligand and/or receptors) can be overexpressed, giving cells a selective growth advantage. The blood-brain barrier is substantially altered in malignant gliomas, resulting in cerebral edema. Therapy for malignant gliomas includes surgery, radiation therapy, and chemotherapy. Surgical resection that leaves little residual tumor produces longer survival than less vigorous surgery. Radiation therapy to a dose of at least 60 Gy is required to treat malignant gliomas. Increased survival beyond that produced by standard external radiotherapy requires much larger doses; interstitial radiotherapy permits such dosing. Radiosurgery is being tested. Chemotherapy with nitrosoureas is modestly useful but appears to benefit patients with anaplastic astrocytoma more so than those with glioblastoma.

Lack of lung hemorrhage in humans after intraoperative transesophageal echocardiography with ultrasound exposure conditions similar to those causing lung hemorrhage in laboratory animals

This study investigated the phenomenon of ultrasonically induced lung hemorrhage in humans. Multiple experimental laboratories have shown that diagnostic ultrasound exposure can cause hemorrhage in the lungs of laboratory animals. The left lung of 50 patients (6 women, 44 men, mean age 61 years) was observed directly by the surgeon after routine intraoperative transesophageal echocardiography was performed. From manufacturer specifications the maximum derated intensity in the sound field of the system used was 186 W/cm2, the maximum derated rarefactional acoustic pressure was 2.4 MPa, and the maximum mechanical index was 1.3. The lowest frequency used was 3.5 MHz. This exposure exceeds the threshold found for surface lung hemorrhage seen on gross observation of laboratory animals. No hemorrhage was noted on any lung surface by the surgeon on gross observation. We conclude that clinical transesophageal echocardiography, even at field levels a little greater than the reported thresholds for lung hemorrhage in laboratory animals, did not cause surface lung hemorrhage apparent on gross observation. These negative results support the conclusion that the human lung is not markedly more sensitive to ultrasound exposure than that of other mammals.

Altered collagen structure in mouse tail tendon lacking the alpha 2(I) chain

Type I collagen is the most prevalent member of the fibril forming family of collagens in higher vertebrates and its heterotrimeric form is comprised of two alpha 1(I) chains and one alpha2(I) polypeptide chain. The functional importance of having two distinct chain types in type I collagen is largely undefined. The existence of a mouse model with a Cola-2 gene mutation (termed oim) that results in non-functional pro alpha 2(I) chains presents a unique opportunity to explore changes in collagen structure resulting from the complete (oim/oim mice) and partial (oim/+ mice) loss of functional alpha 2(I) chains. Tail tendon is a tissue with a well-defined, hierarchical organization of type I collagen. X-ray diffraction studies on oim/oim versus control tendons indicate that the total absence of alpha 2(I) chains results in a decrease in the order of axial packing and a loss of crystalline lateral packing. This suggests that the non-equivalence of three chains is an important determinant of lateral interactions between adjacent molecules and may be involved in the long-range axial order in type I collagen-containing tissues. Both homotrimeric and heterotrimeric type I collagen molecules are found in heterozygous oim mice and these appear to be present in the same co-polymeric fibrils, preventing crystalline lateral packing. In addition to these changes at a fibrillar level, the absence of the alpha 2(I) chain results in an increased enzymatic susceptibility at one site. The oim/oim mice are observed to have reduced body size and smaller tendon bundles, which may be a consequence of these molecular and fibrillar changes in collagen. Furthermore, it is likely that a similar alteration in the molecular packing of collagen in bone fibrils contributes to the osteopenia and decreased bone strength in mice with the oim mutation that are also characteristic of human osteogenesis imperfecta.

Age-related changes in effects of insulin-like growth factor I on human osteoblast-like cells

The role of insulin-like growth factor I (IGF-I) in extracellular matrix metabolism was studied in both proliferating and confluent human osteoblast-like cultures derived from donors of different ages. In proliferating cultures, recombinant human (rh)IGF-I was found to increase the incorporation of [3H]thymidine in a dose- and age-dependent manner. To study cell proliferation dynamically, continuous growth curves with and without rhIGF-I were modelled by a modified logistic function. Increasing doses of rhIGF-I decreased the lag time and maximal growth rates, whereas plateau values decreased only at the highest dose (100 ng/ml). In post-proliferative cell strains, rhIGF-I (0.1-100 ng/ml) increased levels of type I collagen, biglycan and decorin, and to a smaller extent fibronectin and thrombospondin, whereas it decreased the levels of hyaluronan and a versican-like proteoglycan when protein and proteoglycan metabolism were followed by steady-state radiolabelling with [3H]proline, [3H]glucosamine or [35S]sulphate. These responses to rhIGF-I were found to be age-dependent, with osteoblast-like cells derived from younger patients being more responsive to rhIGF-I. When extracellular matrix turnover was analysed by pulse-chase experiments, rhIGF-I had no effect. The steady-state levels of collagen, decorin, hyaluronan and a versican-like proteoglycan for bone cells treated with rhIGF-I on day 7 in culture were equivalent to levels of these matrix components in untreated osteoblasts grown for 14 days. These results are consistent with rhIGF-I's altering cellular proliferative capacity and matrix synthesis, causing a change in the osteoblast differentiated state.