Mechanically Ventilated Patients With Coronavirus Disease 2019 Had a Higher Chance of In-Hospital Death If Treated With High-Flow Nasal Cannula Oxygen Before Intubation

BACKGROUND

The impact of high-flow nasal cannula (HFNC) on outcomes of patients with respiratory failure from coronavirus disease 2019 (COVID-19) is unknown. We sought to assess whether exposure to HFNC before intubation was associated with successful extubation and in-hospital mortality compared to patients receiving intubation only.

METHODS

This single-center retrospective study examined patients with COVID-19-related respiratory failure from March 2020 to March 2021 who required HFNC, intubation, or both. Data were abstracted from the electronic health record. Use and duration of HFNC and intubation were examined' as well as demographics and clinical characteristics. We assessed the association between HFNC before intubation (versus without) and chance of successful extubation and in-hospital death using Cox proportional hazards models adjusting for age, sex, race/ethnicity, obesity, hypertension, diabetes, prior chronic obstructive pulmonary disease or asthma, HCO 3 , CO 2 , oxygen-saturation-to-inspired-oxygen (S:F) ratio, pulse, respiratory rate, temperature, and length of stay before intervention.

RESULTS

A total of n = 440 patients were identified, of whom 311 (70.7%) received HFNC before intubation, and 129 (29.3%) were intubated without prior use of HFNC. Patients who received HFNC before intubation had a higher chance of in-hospital death (hazard ratio [HR], 2.08; 95% confidence interval [CI], 1.06-4.05). No difference was found in the chance of successful extubation between the 2 groups (0.70, 0.41-1.20).

CONCLUSIONS

Among patients with respiratory failure from COVID-19 requiring mechanical ventilation, patients receiving HFNC before intubation had a higher chance of in-hospital death. Decisions on initial respiratory support modality should weigh the risks of intubation with potential increased mortality associated with HFNC.

Unwanted abortion disclosure and social support in the abortion decision and mental health symptoms: A cross-sectional survey

OBJECTIVES

To assess the extent of unwanted abortion disclosure and levels of social support in the abortion decision and their association with depression, anxiety, and stress.

STUDY DESIGN

From January to June 2019, we surveyed people presenting for abortion at four clinics in California, New Mexico, and Illinois regarding their experiences accessing abortion. We used multivariable regression to examine associations between unwanted abortion disclosure and social support in the abortion decision, and symptoms of depression, anxiety and stress.

RESULTS

Among 1092 people approached, 784 (72% response rate) eligible individuals initiated the survey, and 746 responded to the unwanted abortion disclosure item and were included in analyses. Over one-quarter (27%) told someone they would have preferred not to tell about their decision, mostly due to obstacles getting to the appointment-time to appointment (46%), travel distance (33%), and costs (32%). Three-quarters (74%, n=546) had at least one person in their life who supported the abortion decision "very much"; 20% had someone who supported the decision "not at all." In adjusted analyses, unwanted abortion disclosure was associated with more symptoms of depression (B = 0.62, 95% confidence interval: 0.28, 0.95), anxiety (B = 1.79; 95% CI: 0.76, 2.82) and stress (B = 1.80, 95% CI: 0.64, 1.72). People also had more symptoms of depression and stress when one or more person (B = 0.64; 95% CI: 0.27, 1.02 and B = 0.75, 95% CI: 0.15, 1.35, respectively) or the man involved in the pregnancy (B = 0.67, 95% CI: 0.16, 1.18 and B = 0.96, 95% CI: 0.13, 1.78, respectively) supported their decision "not at all" (vs "very much" support).

CONCLUSION

Being forced to disclose the abortion decision due to logistical and cost constraints may be harmful to people's mental health.

IMPLICATIONS

Logistical burdens such as travel, time to access care, and costs needed to access abortion may force people seeking abortion to involve others who are unsupportive in the abortion decision having negative implications for their mental health.

Serological response to vaccination in post-acute sequelae of COVID

BACKGROUND

Individuals with post-acute sequelae of COVID (PASC) may have a persistence in immune activation that differentiates them from individuals who have recovered from COVID without clinical sequelae. To investigate how humoral immune activation may vary in this regard, we compared patterns of vaccine-provoked serological response in patients with PASC compared to individuals recovered from prior COVID without PASC.

METHODS

We prospectively studied 245 adults clinically diagnosed with PASC and 86 adults successfully recovered from prior COVID. All participants had measures of humoral immunity to SARS-CoV-2 assayed before or after receiving their first-ever administration of COVID vaccination (either single-dose or two-dose regimen), including anti-spike (IgG-S and IgM-S) and anti-nucleocapsid (IgG-N) antibodies as well as IgG-S angiotensin-converting enzyme 2 (ACE2) binding levels. We used unadjusted and multivariable-adjusted regression analyses to examine the association of PASC compared to COVID-recovered status with post-vaccination measures of humoral immunity.

RESULTS

Individuals with PASC mounted consistently higher post-vaccination IgG-S antibody levels when compared to COVID-recovered (median log IgG-S 3.98 versus 3.74, P < 0.001), with similar results seen for ACE2 binding levels (median 99.1 versus 98.2, P = 0.044). The post-vaccination IgM-S response in PASC was attenuated but persistently unchanged over time (P = 0.33), compared to in COVID recovery wherein the IgM-S response expectedly decreased over time (P = 0.002). Findings remained consistent when accounting for demographic and clinical variables including indices of index infection severity and comorbidity burden.

CONCLUSION

We found evidence of aberrant immune response distinguishing PASC from recovered COVID. This aberrancy is marked by excess IgG-S activation and ACE2 binding along with findings consistent with a delayed or dysfunctional immunoglobulin class switching, all of which is unmasked by vaccine provocation. These results suggest that measures of aberrant immune response may offer promise as tools for diagnosing and distinguishing PASC from non-PASC phenotypes, in addition to serving as potential targets for intervention.

Condom Use Behaviors, Risk Perception, and Partner Communication Following Oral HIV Self-testing Among Adolescents and Young Adults in Kenya: A Cohort Study

HIV self-testing (HIVST) can improve testing completion among adolescents and young adults (AYA), although its influence on sexual behaviors is unclear. We evaluated whether HIVST was associated with changes in talking with sexual partners about HIVST, condom use, and HIV risk perception among AYA ages 15-24 years in a study of HIVST distribution through homes, pharmacies, and nightclubs in Nairobi, Kenya. All participants had negative HIVST results. Regression models were used to evaluate changes between pre-HIVST and 4 months post-HIVST. Overall, there was a significant increase in talking with sexual partners about HIVST. There was a significant reduction in number of condomless sex acts among AYA recruited through pharmacies and homes. Unexpectedly, among females, there was a significant decrease in consistent condom use with casual partners. HIVST services for AYA may benefit from including strategies to support condom use and partner communication about self-testing adapted to specific populations and partnerships.

Apparent Risks of Postural Orthostatic Tachycardia Syndrome Diagnoses After COVID-19 Vaccination and SARS-Cov-2 Infection

Postural orthostatic tachycardia syndrome (POTS) has been previously described after SARS-CoV-2 infection; however, limited data is available on the relation of POTS with COVID-19 vaccination. Here we show in a cohort of 284,592 COVID-19 vaccinated individuals using a sequence-symmetry analysis, that the odds of POTS are higher 90 days after vaccine exposure than 90 days prior to exposure, and that the odds for POTS are higher than referent conventional primary care diagnoses, but lower than the odds of new POTS diagnosis after SARS-CoV-2 infection. Our results identify a possible association between COVID-19 vaccination and incidence of POTS. Notwithstanding the probable low incidence of POTS after COVID-19 vaccination, particularly when compared to SARS-Cov-2 post-infection odds which were five times higher, our results suggest that further studies, are needed to investigate the incidence and etiology of POTS occurring after COVID-19 vaccination.

Cardiovascular and hepatic disease associations by magnetic resonance imaging: A retrospective cohort study

Background

Hepatic disease is linked to cardiovascular events but the independent association between hepatic and cardiovascular disease remains unclear, given shared risk factors.

Methods

This was a retrospective study of consecutive patients with a clinical cardiac MRI (CMR) and a serological marker of hepatic fibrosis, the FIB-4 score, within one year of clinical imaging. We assessed the relations between FIB-4 scores grouped based on prior literature: low (< 1.3), moderate (1.3–3.25), and high (>3.25), and abnormalities detected by comprehensive CMR grouped into 4 domains: cardiac structure (end diastolic volumes, atrial dimensions, wall thickness); cardiac function (ejection fractions, wall motion abnormalities, cardiac output); vascular structure (ascending aortic and pulmonary arterial sizes); and cardiac composition (late gadolinium enhancement, T1 and T2 times). We used Poisson regression to examine the association between the conventionally defined FIB-4 category (low <1.3, moderate 1.3–3.25, and high >3.25) and any CMR abnormality while adjusting for demographics and traditional cardiovascular risk factors.

Results

Of the 1668 patients studied (mean age: 55.971 ± 7.28, 901 [54%] male), 85.9% had ≥1 cardiac abnormality with increasing prevalence seen within the low (82.0%) to moderate (88.8%) to high (92.3%) FIB-4 categories. Multivariable analyses demonstrated the presence of any cardiac abnormality was significantly associated with having a high-range FIB-4 (prevalence ratio 1.07, 95% CI: 1.01–1.13); notably, the presence of functional cardiac abnormalities were associated with being in the high FIB-4 range (1.41, 1.21–1.65) and any vascular abnormalities with being in the moderate FIB-4 range (1.22, 1.01–1.47).

Conclusions

Elevated FIB-4 was associated with cardiac functional and vascular abnormalities even after adjustment for shared risk factors in a cohort of patients with clinically referred CMR. These CMR findings indicate that cardiovascular abnormalities exist in the presence of subclinical hepatic fibrosis, irrespective of shared risk factors, underscoring the need for further studies of the heart-liver axis.

Evidence of premature lymphocyte aging in people with low anti-spike antibody levels after BNT162b2 vaccination

SARS-CoV-2 vaccines have unquestionably blunted the overall impact of the COVID-19 pandemic, but host factors such as age, sex, obesity, and other co-morbidities can affect vaccine efficacy. We identified individuals in a relatively healthy population of healthcare workers (CORALE study cohort) who had unexpectedly low peak anti-spike receptor binding domain (S-RBD) antibody levels after receiving the BNT162b2 vaccine. Compared to matched controls, "low responders" had fewer spike-specific antibody-producing B cells after the second and third/booster doses. Moreover, their spike-specific T cell receptor (TCR) repertoire had less depth and their CD4⁺ and CD8⁺T cell responses to spike peptide stimulation were less robust. Single cell transcriptomic evaluation of peripheral blood mononuclear cells revealed activation of aging pathways in low responder B and CD4⁺T cells that could underlie their attenuated anti-S-RBD antibody production. Premature lymphocyte aging may therefore contribute to a less effective humoral response and could reduce vaccination efficacy.

Variability independent of mean blood pressure as a real-world measure of cardiovascular risk

BACKGROUND

Individual-level blood pressure (BP) variability, independent of mean BP levels, has been associated with increased risk for cardiovascular events in cohort studies and clinical trials using standardized BP measurements. The extent to which BP variability relates to cardiovascular risk in the real-world clinical practice setting is unclear. We sought to determine if BP variability in clinical practice is associated with adverse cardiovascular outcomes using clinically generated data from the electronic health record (EHR).

METHODS

We identified 42,482 patients followed continuously at a single academic medical center in Southern California between 2013 and 2019 and calculated their systolic and diastolic BP variability independent of the mean (VIM) over the first 3 years of the study period. We then performed multivariable Cox proportional hazards regression to examine the association between VIM and both composite and individual outcomes of interest (incident myocardial infarction, heart failure, stroke, and death).

FINDINGS

Both systolic (HR, 95% CI 1.22, 1.17-1.28) and diastolic VIM (1.24, 1.19-1.30) were positively associated with the composite outcome, as well as all individual outcome measures. These findings were robust to stratification by age, sex and clinical comorbidities. In sensitivity analyses using a time-shifted follow-up period, VIM remained significantly associated with the composite outcome for both systolic (1.15, 1.11-1.20) and diastolic (1.18, 1.13-1.22) values.

INTERPRETATION

VIM derived from clinically generated data remains associated with adverse cardiovascular outcomes and represents a risk marker beyond mean BP, including in important demographic and clinical subgroups. The demonstrated prognostic ability of VIM derived from non-standardized BP readings indicates the utility of this measure for risk stratification in a real-world practice setting, although residual confounding from unmeasured variables cannot be excluded.

FUNDING

This study was funded in part by National Institutes of Health grants R01-HL134168, R01-HL131532, R01-HL143227, R01-HL142983, U54-AG065141; R01-HL153382, K23-HL136853, K23-HL153888, and K99-HL157421; China Scholarship Council grant 201806260086; Academy of Finland (Grant no: 321351); Emil Aaltonen Foundation; Finnish Foundation for Cardiovascular Research.

Demographic and clinical characteristics associated with variations in antibody response to BNT162b2 COVID-19 vaccination among healthcare workers at an academic medical centre: a longitudinal cohort analysis

OBJECTIVES

We sought to understand the demographic and clinical factors associated with variations in longitudinal antibody response following completion of two-dose regiment of BNT162b2 vaccination.

DESIGN

This study is a 10-month longitudinal cohort study of healthcare workers and serially measured anti-spike protein IgG (IgG-S) antibody levels using mixed linear models to examine their associations with participant characteristics.

SETTING

A large, multisite academic medical centre in Southern California, USA.

PARTICIPANTS

A total of 843 healthcare workers met inclusion criteria including completion of an initial two-dose course of BNT162b2 vaccination, complete clinical history and at least two blood samples for analysis. Patients had an average age of 45±13 years, were 70% female and 7% with prior SARS-CoV-2 infection.

RESULTS

Vaccine-induced IgG-S levels remained in the positive range for 99.6% of individuals up to 10 months after initial two-dose vaccination. Prior SARS-CoV-2 infection was the primary correlate of sustained higher postvaccination IgG-S levels (partial R2=0.133), with a 1.74±0.11 SD higher IgG-S response (p<0.001). Female sex (beta 0.27±0.06, p<0.001), younger age (0.01±0.00, p<0.001) and absence of hypertension (0.17±0.08, p=0.003) were also associated with persistently higher IgG-S responses. Notably, prior SARS-CoV-2 infection augmented the associations of sex (-0.42 for male sex, p=0.08) and modified the associations of hypertension (1.17, p=0.001), such that infection-naïve individuals with hypertension had persistently lower IgG-S levels whereas prior infected individuals with hypertension exhibited higher IgG-S levels that remained augmented over time.

CONCLUSIONS

While the IgG-S antibody response remains in the positive range for up to 10 months following initial mRNA vaccination in most adults, determinants of sustained higher antibody levels include prior SARS-CoV-2 infection, female sex, younger age and absence of hypertension. Certain determinants of the longitudinal antibody response appear significantly modified by prior infection status. These findings offer insights regarding factors that may influence the 'hybrid' immunity conferred by natural infection combined with vaccination.

Seasonal COVID-19 surge related hospital volumes and case fatality rates

BACKGROUND

Seasonal and regional surges in COVID-19 have imposed substantial strain on healthcare systems. Whereas sharp inclines in hospital volume were accompanied by overt increases in case fatality rates during the very early phases of the pandemic, the relative impact during later phases of the pandemic are less clear. We sought to characterize how the 2020 winter surge in COVID-19 volumes impacted case fatality in an adequately-resourced health system.

METHODS

We performed a retrospective cohort study of all adult diagnosed with COVID-19 in a large academic healthcare system between August 25, 2020 to May 8, 2021, using multivariable logistic regression to examine case fatality rates across 3 sequential time periods around the 2020 winter surge: pre-surge, surge, and post-surge. Subgroup analyses of patients admitted to the hospital and those receiving ICU-level care were also performed. Additionally, we used multivariable logistic regression to examine risk factors for mortality during the surge period.

RESULTS

We studied 7388 patients (aged 52.8 ± 19.6 years, 48% male) who received outpatient or inpatient care for COVID-19 during the study period. Patients treated during surge (N = 6372) compared to the pre-surge (N = 536) period had 2.64 greater odds (95% CI 1.46-5.27) of mortality after adjusting for sociodemographic and clinical factors. Adjusted mortality risk returned to pre-surge levels during the post-surge period. Notably, first-encounter patient-level measures of illness severity appeared higher during surge compared to non-surge periods.

CONCLUSIONS

We observed excess mortality risk during a recent winter COVID-19 surge that was not explained by conventional risk factors or easily measurable variables, although recovered rapidly in the setting of targeted facility resources. These findings point to how complex interrelations of population- and patient-level pandemic factors can profoundly augment health system strain and drive dynamic, if short-lived, changes in outcomes.

Sex-Specific Temporal Trends in Hypertensive Crisis Hospitalizations in the United States

Background

Despite recent improvements in hypertension control overall, the extent to which these trends apply to the most extreme forms of elevated blood pressure—hypertensive crises requiring hospitalization—in both women and men at risk remains unknown.

Methods and Results

Using data from the National Inpatient Sample, we estimated sex‐pooled and sex‐specific temporal trends in hypertensive crisis hospitalization and case fatality rates over serial time periods: years 2002 to 2006, 2007 to 2011, and 2012 to 2014. Over the entire study period (years 2002–2014), there were an estimated 918 392±9331 hypertensive crisis hospitalizations and 4377±157 in‐hospital deaths. Hypertensive crisis represented 0.23%±0.002% of all hospitalizations during the entire study period: 0.24%±0.002% for men and 0.22%±0.002% for women. In multivariable analyses adjusting for age, race or ethnicity, and cardiovascular conditions, the odds of experiencing a hospitalization primarily for hypertensive crisis increased annually for both men (odds ratio [OR], 1.083 per year; 95% CI, 1.08–1.09) and women (OR, 1.07 per year, 95% CI, 1.07–1.08) with a higher rate of increase observed in men compared with women (P<0.001). The multivariable‐adjusted odds of death during hypertensive crisis hospitalization decreased annually and similarly for men (OR, 0.89 per year; 95% CI, 0.86–0.92) and for women (0.92 per year; 95% CI, 0.90–0.94).

Conclusions

Hypertensive crisis hospitalizations have steadily increased, slightly more among men than women, along with an observed increase in the burden of cardiovascular conditions. These trends, observed despite contemporaneous improvements in hypertension prevention and control nationwide, warrant further investigations to identify contributing factors that could be amenable to targeted interventions.

Symptomology following mRNA vaccination against SARS-CoV-2

Despite demonstrated efficacy of vaccines against severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), the causative agent of coronavirus disease-2019 (COVID-19), widespread hesitancy to vaccination persists. Improved knowledge regarding frequency, severity, and duration of vaccine-associated symptoms may help reduce hesitancy. In this prospective observational study, we studied 1032 healthcare workers who received both doses of the Pfizer-BioNTech SARS-CoV-2 mRNA vaccine and completed post-vaccine symptom surveys both after dose 1 and after dose 2. We defined appreciable post-vaccine symptoms as those of at least moderate severity and lasting at least 2 days. We found that symptoms were more frequent following the second vaccine dose than the first (74% vs. 60%, P < 0.001), with >80% of all symptoms resolving within 2 days. The most common symptom was injection site pain, followed by fatigue and malaise. Overall, 20% of participants experienced appreciable symptoms after dose 1 and 30% after dose 2. In multivariable analyses, female sex was associated with greater odds of appreciable symptoms after both dose 1 (OR, 95% CI 1.73, 1.19-2.51) and dose 2 (1.76, 1.28-2.42). Prior COVID-19 was also associated with appreciable symptoms following dose 1, while younger age and history of hypertension were associated with appreciable symptoms after dose 2. We conclude that most post-vaccine symptoms are reportedly mild and last <2 days. Appreciable post-vaccine symptoms are associated with female sex, prior COVID-19, younger age, and hypertension. This information can aid clinicians in advising patients on the safety and expected symptomatology associated with vaccination.

Temporal variations in the severity of COVID-19 illness by race and ethnicity

Introduction

Early reports highlighted racial/ethnic disparities in the severity of COVID-19 seen across the USA; the extent to which these disparities have persisted over time remains unclear. Our research objective was to understand temporal trends in racial/ethnic variation in severity of COVID-19 illness presenting over time.

Methods

We conducted a retrospective cohort analysis using longitudinal data from Cedars-Sinai Medical Center, a high-volume health system in Southern California. We studied patients admitted to the hospital with COVID-19 illness from 4 March 2020 through 5 December 2020. Our primary outcome was COVID-19 severity of illness among hospitalised patients, assessed by racial/ethnic group status. We defined overall illness severity as an ordinal outcome: hospitalisation but no intensive care unit (ICU) admission; admission to the ICU but no intubation; and intubation or death.

Results

A total of 1584 patients with COVID-19 with available demographic and clinical data were included. Hispanic/Latinx compared with non-Hispanic white patients had higher odds of experiencing more severe illness among hospitalised patients (OR 2.28, 95% CI 1.62 to 3.22) and this disparity persisted over time. During the initial 2 months of the pandemic, non-Hispanic blacks were more likely to suffer severe illness than non-Hispanic whites (OR 2.02, 95% CI 1.07 to 3.78); this disparity improved by May, only to return later in the pandemic.

Conclusion

In our patient sample, the severity of observed COVID-19 illness declined steadily over time, but these clinical improvements were not seen evenly across racial/ethnic groups; greater illness severity continues to be experienced among Hispanic/Latinx patients.

Immunogenicity of Alternative Dosing Schedules for HPV Vaccines among Adolescent Girls and Young Women: A Systematic Review and Meta-Analysis

Alternative dosing schedules for licensed human papilloma virus (HPV) vaccines, particularly single dose and extended intervals between doses (>12 months), are being considered to address vaccine shortages and improve operational flexibility. We searched PUBMED/MEDLINE for publications reporting immunogenicity data following administration of one of the licensed HPV vaccines (2vHPV, 4vHPV, and 9vHPV) to females aged 9–26 years. We conducted non-inferiority analyses comparing alternative to standard schedules using mixed effects meta-regression controlling for baseline HPV status and disaggregated by vaccine, subtype, time point, and age group (9–14 and 15–26 years). Non-inferiority was defined as the lower bound of the 95% confidence interval (CI) for the geometric mean titer (GMT) ratio being greater than 0.5. Our search returned 2464 studies, of which 23 were included in data analyses. When evaluated against standard schedules, although robust immunogenicity was demonstrated across all multi-dose groups, non-inferiority of extended interval dosing was mixed across vaccines, subtypes, and time points. Single dose did not meet the criteria for non-inferiority in any comparisons. Sparse data limited the number of possible comparisons, and further research is warranted.

Long-term Results with Hydroxylapatite Middle Ear Implants

PURPOSE: This study evaluated long-term results in patients who had ossicular reconstruction with a Goldenberg hydroxylapatite implant.

METHODS: A total of 233 patients underwent implantation; of these, 77 had 5-year or longer follow-up and are the subjects of this study of long-term hearing results. All 233 patients were included for analysis of extrusion rate and postoperative otorrhea.

RESULTS: The hearing success rate at long-term follow-up was 56.8%; the mean air-bone gap was 21.1 dB. Prosthesis extrusion occurred in 5.29% of the 233 patients, and visible slippage occurred in 7.7%. Overall, 50.6% of patients met the criteria for successful hearing, which included no extrusion and a dry ear. Better hearing before surgery and presence of the malleus long process were factors associated with a successful hearing result, as was tympanoplasty alone and canal wall up tympa-nomastoidectomy.

CONCLUSION: Hydroxylapatite hybrid prostheses provide stable hearing results over time with low extrusion and a dry ear overall.

Cannabis use and anxiety: is stress the missing piece of the puzzle?

OBJECTIVE

Comorbidity between anxiety and cannabis use is common yet the nature of the association between these conditions is not clear. Four theories were assessed, and a fifth hypothesis tested to determine if the misattribution of stress symptomology plays a role in the association between state-anxiety and cannabis.

METHODS

Three-hundred-sixteen participants ranging in age from 18 to 71 years completed a short online questionnaire asking about their history of cannabis use and symptoms of stress and anxiety.

RESULTS

Past and current cannabis users reported higher incidence of lifetime anxiety than participants who had never used cannabis; however, these groups did not differ in state-anxiety, stress, or age of onset of anxiety. State-anxiety and stress were not associated with frequency of cannabis use, but reported use to self-medicate for anxiety was positively associated with all three. Path analyses indicated two different associations between anxiety and cannabis use, pre-existing and high state-anxiety was associated with (i) higher average levels of intoxication and, in turn, acute anxiety responses to cannabis use; (ii) frequency of cannabis use via the mediating effects of stress and self-medication.

CONCLUSION

None of the theories was fully supported by the findings. However, as cannabis users reporting self-medication for anxiety were found to be self-medicating stress symptomology, there was some support for the stress-misattribution hypothesis. With reported self-medication for anxiety being the strongest predictor of frequency of use, it is suggested that researchers, clinicians, and cannabis users pay greater attention to the overlap between stress and anxiety symptomology and the possible misinterpretation of these related but distinct conditions.

Blood cell adhesion on sensor materials studied by light, scanning electron, and atomic-force microscopy

Unwanted interactions of biomedical sensors with surrounding tissues, body fluids, and cells are one of the most crucial problems affecting their long-term stability. In vivo processes were simulated in a computer-controlled bioreactor connected to a flow chamber system. Optical sensor materials were inserted into a parallel-plate chamber and monitored by light microscopy in order to get information about the number of adhered cells. Tests with thrombocyte-enriched plasma show that novel phosphorylcholine (PC)-polymer-coated sensors appear to be more bioinert, and thus demonstrate better haemocopatibility in comparison with untreated glass sensors. The influence of different materials on the morphology of adhered cells was investigated by off-line methods such as scanning electron microscopy (SEM) and atomic-force microscopy (AFM). SEM showed a reduction in the number of adhered thrombocytes and the lack of any fibrin network on the PC-polymer-modified glass surface, in contrast to the pure glass surface. AFM gives topographical information, and the calculated contact areas and cell volumes indicate smaller interactions between cells and sensor material in the case of PC-polymer-coated sensors.

Fiber-optic luminescent sensors with composite oxygen-sensitive layers and anti-biofouling coatings

Anti-biofouling polymers containing phosphorylcholine (PC)-substituted methacrylate units have been prepared by copolymerization with dodecyl methacrylate and used to coat luminescent oxygen sensors. Nanometer-sized coatings of such materials are shown to reduce significantly the adhesion of marine bacteria (more than 70%) and thrombocytes (more than 90%) to the surface of tris-(4,7-diphenyl-1,10-phenanthroline)ruthenium(II)-doped silicone layers. A thorough analytical characterization of both the PC-coated and the uncoated dyed films has demonstrated that the anti-biofouling layers do not alter dramatically the performance of the fiber-optic oxygen sensors in aqueous media and are mechanically stable for more than one year of continuous immersion. The slope of the linear calibration plots in the 0-8 mg L(-1) oxygen concentration range (ca. 1.0 L mg(-1)) decreases 8-11% after applying the 50-nm protective layer with no change in the sensor precision (1.1-1.9% RSD, n = 6). The response time of the 200-microm O2-sensitive layers (1.5-6 min) increases up to 2-fold, depending on the nature of the PC polymer used, but the temperature effect on the sensor response (0.020 L mg(-1) degrees C(-1)) remains essentially unchanged. Oxygen detection limits as low as 0.04 mg L(-1) have been measured with the coated optodes. The novel biofouling-resistant optosensors have been successfully validated against a commercial oxygen electrode and are shown to respond faster than the electrochemical device for large oxygen concentration changes. The biomimetic coatings will be particularly useful for drift-free long-term operation of environmental optosensors and in vivo fiber-optic oxygen analyzers.

Long-term results with hydroxylapatite middle ear implants

PURPOSE

This study evaluated long-term results in patients who had ossicular reconstruction with a Goldenberg hydroxylapatite implant.

METHODS

A total of 233 patients underwent implantation; of these, 77 had 5-year or longer follow-up and are the subjects of this study of long-term hearing results. All 233 patients were included for analysis of extrusion rate and postoperative otorrhea.

RESULTS

The hearing success rate at long-term follow-up was 56.8%; the mean air-bone gap was 21.1 dB. Prosthesis extrusion occurred in 5.29% of the 233 patients, and visible slippage occurred in 7.7%. Overall, 50. 6% of patients met the criteria for successful hearing, which included no extrusion and a dry ear. Better hearing before surgery and presence of the malleus long process were factors associated with a successful hearing result, as was tympanoplasty alone and canal wall up tympanomastoidectomy.

CONCLUSION

Hydroxylapatite hybrid prostheses provide stable hearing results over time with low extrusion and a dry ear overall.

Single-dose pharmacokinetics of delavirdine mesylate and didanosine in patients with human immunodeficiency virus infection

Delavirdine is a nonnucleoside reverse transcriptase inhibitor with in vitro activity against human immunodeficiency virus type 1 (HIV-1) that is currently being evaluated in combination regimens with various nucleoside analogs, including didanosine. Due to the pH-dependent solubility of delavirdine, the buffering agents in didanosine formulations may reduce delavirdine absorption. To evaluate the potential interaction between these agents, 12 HIV-infected patients (mean [+/- standard deviation] CD4+ cell count, 304 +/- 213/mm3) were enrolled in a three-way crossover single-dose study. Didanosine (125 to 200 mg given as buffered tablets) and delavirdine mesylate (400 mg) pharmacokinetics were evaluated when each drug was given alone (treatments A and B, respectively), when the two drugs were given concurrently (treatment C), and when didanosine was given 1 h after delavirdine (treatment D). Delavirdine exposure was reduced by concurrent administration of didanosine. The maximum drug concentration in serum (Cmax) was reduced from 7.22 +/- 4.0 to 3.51 +/- 1.9 microM, and the area under the concentration-time curve from 0 h to infinity (AUC0-->infinity) was reduced from 22.5 +/- 14 to 14 +/- 5.7 microM.h. The extent of N-dealkylation, as indicated by the ratio of the N-dealkylated delavirdine AUC0-->infinity to the delavirdine AUC0-->infinity, was unchanged across study treatments (P = 0.708). Reductions in didanosine exposure were observed during concurrent administration with delavirdine with a Cmax reduction from 4.65 +/- 2.0 to 3.22 +/- 0.59 microM and an AUC0-->infinity reduction from 7.93 +/- 3.9 to 6.54 +/- 2.3 microM.h. Thus, concurrent administration of delavirdine and didanosine may reduce the AUC0-->infinity of both drugs, although the clinical significance of this reduction is unknown. Administration of delavirdine 1 h before didanosine avoided the interaction. Due to the single-dose nature of this study, these findings require further evaluation at steady state.

Does the morphology of the extrahepatic biliary remnants in biliary atresia influence survival? A review of 205 cases

Resected extrahepatic remnants taken at the time of portoenterostomy were examined in a single-center review of 205 cases of biliary atresia. The morphological features of the size and number of residual ducts at the porta hepatis and the degree of inflammation at the porta hepatis were analyzed using a semiquantitative scoring system. The morphology of the common hepatic and common bile duct was classified into seven types. These features were then related to age at time of initial surgery and to survival. This showed that few or absent ductal remnants at the porta hepatis and absence of portal inflammation were predictors of poor prognosis. These histological features may represent the "burnt out" end result of the disease process. There was no correlation between age at time of portoenterostomy and either portal duct patency or portal inflammation. The common hepatic and common bile duct were variably involved in the sclerosing process, but the patterns of obliteration were not indicative of prognosis. The severity of intrahepatic biliary cholangiopathy and the extent of liver damage may ultimately be more important to survival in the long term.

Extrahepatic biliary atresia: a first-trimester event? Clues from light microscopy and immunohistochemistry

Biliary atresia is an obliterative disorder of the bile ducts, causing obstructive jaundice in neonates. In this study, the developing biliary system of normal human embryos and fetuses was examined and compared with the resected extrahepatic biliary remnants from 205 cases of biliary atresia. At the porta hepatis level, it was found that the primary biliary ductal plate undergoes a specific sequence of remodelling, resulting in the formation of large tubular bile ducts surrounded by thick mesenchyme, between 11 and 13 weeks postfertilisation. These developing ducts are in luminal continuity with the extrahepatic biliary tree throughout gestation. Contrary to long-held belief, no "solid phase" was observed in the development of the extrahepatic bile duct. Examination of the biliary remnants in biliary atresia showed that the porta hepatis is encased in fibrous tissue, and a variable pattern of obliteration of the common hepatic and common bile ducts was observed. Anticytokeratin immunostaining showed similarities between the abnormal ductules within the porta hepatis in biliary atresia, and the developing bile ducts in the first trimester. Biliary atresia may be caused by failure of the remodelling process at the hepatic hilum, with persistence of fetal bile ducts poorly supported by mesenchyme. As bile flow increases perinatally, bile leakage from these abnormal ducts may trigger an intense inflammatory reaction, with subsequent obliteration of the biliary tree.

Non-communicating multiseptate gall bladder and choledochal cyst: a case report and review of publications

A 14 year old girl with multiseptate gall bladder and cystic dilatation of the biliary tree is presented. This is the 20th published case report of patients with multiseptate gall bladder and only the second to be associated with a choledochal cyst. The cystic spaces of the gall bladder did not communicate with the neck of the gall bladder or the rest of the biliary tree, and this unusual feature has not been previously described. A multiseptate gall bladder with a normal biliary tree commonly causes symptoms suggestive of cholecystitis, although gall stones are seldom present. Diagnosis is confirmed by an oral cholecystogram or ultrasound scan that may show the fine intraluminal septae, and these features should be looked for in patients with biliary symptoms without biliary calculi. Cholecystectomy is curative for the isolated gall bladder anomaly but hepaticojejunostomy may be necessary for an associated choledochal cyst.

Hepatic histology and the development of esophageal varices in biliary atresia

Histological features in liver biopsy specimens taken from 71 infants at the time of surgery for biliary atresia (portoenterostomy) were analyzed using a scoring system and compared with an endoscopic grading of esophageal varices performed at a mean age of 3.4 years. The analysis showed no correlation between a "global" score, which represented the severity of all histological changes in the original biopsy specimen, and the severity of esophageal varices. Further analysis also showed no correlation with any individual histological feature (eg, fibrosis). These findings failed to confirm a previous study, which suggested a relationship between liver changes at surgery and the later development of esophageal varices in children with biliary atresia.

Growth of the normal human lower urinary tract from 12 to 21 weeks gestation

Normal development of the human lower urinary tract was studied between the 14th and 20th week of gestation using 3 modes of fixation. Fixation by direct distension provides a high degree of reproducibility of parameters used to study the growth of the fetal bladder. Using this method, fetuses ranging from 12 to 21 weeks gestation were studied. Results obtained demonstrate that the length of the bladder, the inter-ureteric distance, and the distance between the apex of the trigone and the distal tip of the urethra occur in a linear mode. Furthermore, the rate of growth of the male urethra was evidently higher when compared to that of the female from the 12th week of gestation. Data from this work can be used for a more accurate assessment of cases with abnormal lower urinary tract development.

Can flow cytometry reduce the workload for cervical screening? The results of a series of 622 specimens

A simple method permitting the flow cytometric examination of cervical specimens has been developed and an assessment made of the feasibility of relying on this method to screen women for cervical neoplasia. Examination of four flow cytometric parameters showed differences between morphologically normal and abnormal specimens and allowed identification of a proportion of the normal specimens. The system had a false negative rate of 8%. Our experience with cervical specimens has revealed a number of problems associated with their examination by flow cytometry and these are discussed.

Perfusion fixation for placental morphologic investigation

Fifty placentas were collected after vaginal delivery or cesarean section from normal and abnormal pregnancies and were fixed under different conditions of perfusion using a peristaltic roller pump. In each case a physiologic-heparin perfusate was used for less than 10 minutes, followed by a buffered solution of glutaraldehyde-formaldehyde. The best results were obtained with placentas from cesarean sections perfused immediately after delivery with a pressure maintained under 60 mm Hg. Placentas of this group were fixed within 30 minutes and electron microscopy demonstrated good preservation of cellular ultrastructure. Perfusion fixation could be performed up to 6 hours after delivery with satisfactory histologic results. In these cases, electron microscopy revealed ischemic changes 10 minutes after delivery and severe necrosis 1 hour after delivery. When the perfusion pressure was maintained over 60 mm Hg, diffuse damage of the villous morphology was observed. Histomorphometric analysis showed significant differences between terminal villi from nonperfused (immersed-fixed) placentas and perfused-fixed placentas. The mean barrier and trophoblastic thicknesses and the mean volume fraction of trophoblast were significantly (P less than .001) increased in the nonperfused group compared with the perfused group.

Correlation of ultrasound and pathologic findings of placental anomalies in pregnancies with elevated maternal serum alpha-fetoprotein

Twenty pregnancies with elevated maternal serum alpha-fetoprotein (MSAFP), a normal fetus and unusual or abnormal placental/cord sonographic features are reported. These include: (A) gigantic enlargement with multiple sonolucent spaces of different size and shape (n = 2; Swiss cheese); (B) placental masses of variable echogenicity (n = 5); (C) cord masses with central echo-dense zone and peripheral hypoechoic areas (n = 2); (D) enlarged placentas with patchy decrease of echogenicity (n = 6; jelly-like); and (E) large sonolucent spaces with turbulent blood flow surrounded by normal placental tissue (n = 5; placental lakes). After delivery, these ultrasound features were compared with pathologic findings. Diffuse mesenchymal hyperplasia of the stem villi were found in the gigantic placentas (n = 2). The placental masses corresponded to chorioangiomas (n = 3), infarct (n = 1) or subamniotic hematoma (n = 1) and the cord masses to angiomyxomas (n = 2). The 'jelly-like' placentas were related to subchorial thrombosis (n = 2), massive fibrin deposition (n = 1) or hypertrophy with no obvious abnormalities (n = 3). Large subchorial thrombosis (n = 2), or no obvious abnormalities (n = 3) were observed in placentas with large lakes. These findings suggest that a large range of placental and cord anomalies are associated with elevated MSAFP and are potentially diagnosable by routine sonographic examination at the time of AFP screening.

Early sonographic diagnosis of body stalk anomaly

Ultrasonographic features of a fetus at 18 weeks of gestation suggesting a body stalk anomaly are presented. These included a large abdominal anterior wall defect in apparent continuity with the placenta, severe kyphoscoliosis of the lower spine, the absence of one kidney, and a very short umbilical cord with only one umbilical artery. The amniotic fluid was reduced and the fetus was almost immobile at short-interval ultrasound examinations. The pregnancy was terminated and autopsy of the fetus showed abnormalities compatible with maldevelopment of both cephalic and caudal embryonic folds.

Ciliogenesis and ciliation of the respiratory epithelium in the human fetal cartilaginous trachea

Ciliogenesis of the respiratory epithelium in the human cartilaginous trachea start during the 12th week of gestation. Ciliary shafts are first seen under the scanning electron microscope during the 13th week. Unlike its membranous counterpart, ciliary shafts appear all over the epithelial surface at almost the same time. Epithelial cells destined to become ciliated cells first develop numerous long and thin microvilli. A process of individual cell extrusion and proliferation of neuroepithelial bodies around the carinal angle precede ciliation in the respiratory epithelium of the cartilaginous trachea. Epithelial cell differentiation patterns in both the cartilaginous and membranous trachea are different. The mechanisms involved in modulating cell differentiation are currently under investigation.

Systemic air embolism during laser bronchoscopy

We report a case of massive, fatal, systemic gas embolism which occurred during the course of laser bronchoscopic resection of a bronchial carcinoma. The clinical features of systemic air embolism are discussed.

The morphology of ciliogenesis in the developing fetal human respiratory epithelium

Segmental imaging studies of the respiratory epithelium from human embryos and fetuses of normal karyotype have demonstrated that ciliogenesis and ciliation of the respiratory epithelium starts at 7 weeks of gestation. Ciliated cell differentiation follows a pre-determined pattern of distribution. It starts exclusively in the upper segment of the membranous trachea and spreads distally. Ciliation of the carinal angle takes place at 8 weeks of gestation. Three patterns of basal body formation were identified. The various morphological features encountered are described and compared with those observed in cases of Immotile Cilia Syndrome and other pathological conditions. Ciliation of the respiratory epithelium in the cartilaginous trachea does not take place until after the 12th week of gestation. The morphological findings identified in our case material are in agreement with those observed in the developing respiratory epithelium of other higher mammals.

Extraction of an infected tusk in an adult African elephant

An 18-year-old African elephant was determined to have a nonrepairable crack in its left tusk. Treatment included extraction of the tusk, using rotational and extractional forces, and administration of antibiotics, followed by 1 year of flushing the opened tusk cavity with warm tap water. Two years after surgery, the elephant was healthy, and the tusk cavity was 80% filled with normal tissue.

Normal venous circulation of the gastroesophageal junction. A route to understanding varices

A study into the normal anatomy of the venous circulation of the gastroesophageal junction was undertaken using three complementary techniques (radiology, corrosion casting, and morphometry). Four distinct zones of venous drainage were defined as follows: (a) gastric zone, characterized by a longitudinal venous distribution; (b) palisade zone, composed of parallel vessels arranged in groups, lying mainly within the lamina propria; (c) perforating zone, characterized by "treble clef" shaped veins, which collect and channel blood into extrinsic veins; and (d) truncal zone, composed of four or five deep lying descending veins. This venous system appeared to be mainly distributed within the esophageal mucosal folds. The anatomic pattern suggests that venous flow is bidirectional at the palisade zone, which acts as a high-resistance watershed region between the portal and azygos systems. In patients with portal hypertension this normal vascular system has to accommodate greatly increased venous flow, and the anatomy as demonstrated here offers insight into variceal development.

Morphometry of the second trimester fetal brain. Comparison of ultrasonographic and post-mortem findings

With the increasing use of ultrasound examination in the antenatal period the lack of morphological correlates has become a problem. This study was carried out in order to correct this deficiency. An antenatal real-time ultrasound scan of the fetal head was performed and measurements of the biparietal diameter, occipitofrontal diameter, head circumference and cerebral ventricle-to-hemisphere ratio were undertaken in 103 fetuses at 13-24 weeks gestation. After prostaglandin termination of pregnancy, the fetal brains were perfused in situ through the right carotid artery with 10% formal saline. Horizontal slices of the fetal head were cut, photographs were obtained and measurements of the same parameters as in the ultrasound examination were undertaken. There is a significant correlation (p less than 0.001) between the ultrasonographic and post-mortem measurements of all parameters. Also several anatomical structures of the fetal brain are now confidently identified in the antenatal ultrasound scan, using the anatomical preparations for comparison.

A form of necrobiosis and atrophy of smooth muscle in diabetic gastric autonomic neuropathy

Pathological changes identified in the muscular wall of the stomach from two young insulin-dependent diabetic patients suffering from severe gastric autonomic neuropathy are presented. Scattered smooth muscle cells appearing as homogeneous round eosinophilic bodies ("M" bodies) among areas of sub-total smooth muscle cell atrophy together with intercellular collagen proliferation were identified in the muscularis propria of the stomach. Ultrastructurally, the "M" bodies are transformed smooth muscle cells undergoing a form of necrobiosis with peculiar intracellular features. These changes appear characteristic of end-stage diabetic gastric autonomic neuropathy when compared with other pathological conditions involving the gastric wall. The degree and extent of involvement of the various components of the gastric wall are discussed.

Demonstration of an epitope of the transferrin receptor in human cervical epithelium--a potentially useful cell marker

The distribution of an epitope of the transferrin receptor in the human uterine cervical epithelium has been investigated. Immunohistochemical staining, both immunofluorescent and immunoperoxidase, was performed on biopsy specimens and cytological samples from normal, dysplastic, and neoplastic cervical epithelia using the monoclonal OKT9 antibody. The results of staining 145 cervical biopsy specimens with OKT9 showed widespread staining in all malignant epithelia and most severely dysplastic epithelia. No such staining was seen in either normal epithelia or in mildly dysplastic epithelia apart from the staining of the basal cell layer in some normal epithelia. The incidence of staining in the 50 cervical cytocentrifuge preparations was not as high as that in the 145 tissue sections. The potential role of the OKT9 antibody in both the screening of cervical cytocentrifuge preparations and the prediction of malignancy is discussed. The antibody is considered to be of more value in the examination of biopsy material than of cytocentrifuge preparations.

Immunohistochemical detection of Ca antigen in normal, dysplastic and neoplastic squamous epithelia of the human uterine cervix

Immunohistochemical staining was performed on biopsies and cytological samples from normal, dysplastic and neoplastic squamous epithelia using the monoclonal Ca 1 antibody. The results of staining 92 biopsies and 20 cytological samples are described and it is reported that positive staining with Ca 1 antibody was detected in normal, dysplastic and neoplastic epithelia. The role of the Ca 1 antibody in the study of cervical cancer is discussed.

Percutaneous lung biopsy: experiences during the first 54 biopsies

The first 54 consecutive percutaneous aspiration biopsies of pulmonary lesions of an ongoing prospective trial performed in this hospital between July 1977 and March 1980 have been evaluated. The technique was found to be safe and provided a reliable and rapid diagnosis. An overall diagnostic accuracy of 83% was achieved. In malignant lesions a correct diagnosis was made in 85% of biopsies. These results are compared with other workers using the same technique and with fiberoptic bronchoscopy and sputum cytology. Aspiration is recommended as an excellent alternative to other more established techniques, particularly in the diagnosis of the peripheral lesion.

Results of surgery in 88 consecutive cases of extrahepatic biliary atresia

Of 88 cases of extrahepatic biliary atresia, satisfactory bile flow has been established in 46% of the patients who have undergone portoenterostomies and in 25% of patients with hepaticojejunostomies. Histological analysis of the extrahepatic biliary tissue has not shown a consistent correlation with outcome of operation, except that the patients with one or two large residual ducts lined with columnar epithelium have a better chance of developing bile flow. Cholangitis developed in 43% of the cases, and co-trimoxazole was not shown to have any beneficial effect in a small prospective trial in 18 patients. Severe haemorrhage from oesophageal varices has occurred in 4 jaundice-free survivors. Seventeen patients are now over 3 years of age and thriving but many show persistent elevation of liver enzymes.

A simplified score for assessment of fetal maturation of newly born infants

A simplified scoring system for clinically determining fetal maturation of newly born infants has been developed and provides accurate assessment of gestational age in either well or sick babies. Certain conditions render individual criteria within the score less reliable but do not significantly lessen the reliability of the total assessment. The optimal age for maturational assessment is between 30 and 42 hours of age.

Value of cytology for detecting endometrial abnormalities in climacteric women receiving hormone replacement therapy

Over six months 113 endometrial specimens from 110 menopausal women receiving hormone replacement therapy were examined by two cytologists and two histopathologists. Specimens were obtained by aspiration with the Isaacs cell sampler immediately before Vabra suction curettage, both procedures being performed in the outpatient department without anaesthetic. The histologists agreed with each other on the classification of 85 specimens (75.2%) and the cytologists agreed on the classification of 44 (38.9%). In only 15 cases (13.3%) did all four observers agree. Of the three cases of cystic or adenomatous hyperplasia detected histologically, only one was diagnosed by cytology. Furthermore, both cases of adenocarcinoma escaped detection by cytology, though a third case--later confirmed-"was suspected by one cytologist alone. Use of the Isaacs endometrial cell sampler cannot be advocated for routine screening of women with climacteric symptoms receiving hormone replacement therapy. Efforts should be made to establish the correct dose and duration of treatment with an oestrogen-progestogen preparation in order to avoid over-stimulating the endometrium and the need for regular screening for endometrial abnormalities.

Epileptogenic lesions in the monkey

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