The efficacy of zuranolone versus placebo in postpartum depression and major depressive disorder: a systematic review and meta-analysis

BACKGROUND

Zuranolone, an oral version of allopregnanolone and neurosteroid, is a novel drug for the treatment of major depressive disorder (MDD) and postpartum depression (PPD).

AIM

The purpose of this systematic review and meta-analysis was to assess the efficacy of zuranolone in the treatment of MDD and PPD.

METHOD

A systematic search was conducted using EBSCOhost to simultaneously search Academic Search Premier, APA PsycArticles, APA PsycInfo, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, CINAHL Ultimate, and MEDLINE with Full Text. Two independent reviewers screened the articles and completed a full-text review using Covidence. The quality of each study was assessed using the Cochrane Risk of Bias tool for randomized trials (RoB 2). A meta-analysis was then conducted using Review Manager (RevMan v5.4) software.

RESULTS

The initial search yielded 127 results, with 6 articles fitting our inclusion and exclusion criteria. All 6 studies, comprising 1707 participants, had an overall low risk of bias. There was a significant decrease in HAM-D scores for MDD at 15 days versus placebo (MD - 2.40, 95% CI - 3.07 to - 1.63; p < .001). When pooling data for PDD, there was an overall significant decrease in HAM-D scores at 15 days versus placebo (MD - 4.06, 95% CI - 4.25 to - 3.87; p < .001).

CONCLUSION

The results suggest that zuranolone can improve symptoms of PPD at 15 days; however, results were not clinically significant for MDD. Future research is needed to evaluate the long-term efficacy of zuranolone in PPD and the treatment efficacy in MDD.

Reduced Readmission and Increased Patient Satisfaction in Post-Cardiac Arrhythmia Ablation: A Randomized Pilot Study

BACKGROUND

Hospital readmissions within 30 days post-cardiac arrhythmia ablation are typically related to postoperative complications and arrhythmia recurrence and considered mostly preventable.

PURPOSE

To evaluate the impact of a cardiac ablation patient education program on hospital readmissions and patient satisfaction.

METHODS

An education intervention was established for patients who underwent cardiac ablation based on the Project RED framework. Hospital readmissions rates 30 days postprocedure and satisfaction via a single-blinded posttest design were assessed to evaluate the program.

RESULTS

Those in the intervention group had a significantly lower rate of 30-day readmissions (7.1% vs 53.3%, P = .014). A large magnitude of effect and higher total patient satisfaction scores were also seen in the intervention group ( M = 633, SD = 78) than in the control group ( M = 508, SD = 137, P = .005).

CONCLUSIONS

Results of this study support the implementation of an enhanced cardiac arrhythmia patient education intervention with consideration of identified facilitators and barriers.

Clinical characteristics, racial inequities, and outcomes in patients with breast cancer and COVID-19: A COVID-19 and cancer consortium (CCC19) cohort study

Background

Limited information is available for patients with breast cancer (BC) and coronavirus disease 2019 (COVID-19), especially among underrepresented racial/ethnic populations.

Methods

This is a COVID-19 and Cancer Consortium (CCC19) registry-based retrospective cohort study of females with active or history of BC and laboratory-confirmed severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection diagnosed between March 2020 and June 2021 in the US. Primary outcome was COVID-19 severity measured on a five-level ordinal scale, including none of the following complications, hospitalization, intensive care unit admission, mechanical ventilation, and all-cause mortality. Multivariable ordinal logistic regression model identified characteristics associated with COVID-19 severity.

Results

1383 female patient records with BC and COVID-19 were included in the analysis, the median age was 61 years, and median follow-up was 90 days. Multivariable analysis revealed higher odds of COVID-19 severity for older age (aOR per decade, 1.48 [95% CI, 1.32-1.67]); Black patients (aOR 1.74; 95 CI 1.24-2.45), Asian Americans and Pacific Islander patients (aOR 3.40; 95 CI 1.70-6.79) and Other (aOR 2.97; 95 CI 1.71-5.17) racial/ethnic groups; worse ECOG performance status (ECOG PS ≥2: aOR, 7.78 [95% CI, 4.83-12.5]); pre-existing cardiovascular (aOR, 2.26 [95% CI, 1.63-3.15])/pulmonary comorbidities (aOR, 1.65 [95% CI, 1.20-2.29]); diabetes mellitus (aOR, 2.25 [95% CI, 1.66-3.04]); and active and progressing cancer (aOR, 12.5 [95% CI, 6.89-22.6]). Hispanic ethnicity, timing, and type of anti-cancer therapy modalities were not significantly associated with worse COVID-19 outcomes. The total all-cause mortality and hospitalization rate for the entire cohort was 9% and 37%, respectively however, it varied according to the BC disease status.

Conclusions

Using one of the largest registries on cancer and COVID-19, we identified patient and BC-related factors associated with worse COVID-19 outcomes. After adjusting for baseline characteristics, underrepresented racial/ethnic patients experienced worse outcomes compared to non-Hispanic White patients.

Funding

This study was partly supported by National Cancer Institute grant number P30 CA068485 to Tianyi Sun, Sanjay Mishra, Benjamin French, Jeremy L Warner; P30-CA046592 to Christopher R Friese; P30 CA023100 for Rana R McKay; P30-CA054174 for Pankil K Shah and Dimpy P Shah; KL2 TR002646 for Pankil Shah and the American Cancer Society and Hope Foundation for Cancer Research (MRSG-16-152-01-CCE) and P30-CA054174 for Dimpy P Shah. REDCap is developed and supported by Vanderbilt Institute for Clinical and Translational Research grant support (UL1 TR000445 from NCATS/NIH). The funding sources had no role in the writing of the manuscript or the decision to submit it for publication.

Clinical trial number

CCC19 registry is registered on ClinicalTrials.gov, NCT04354701.

Total ischemic time and age as predictors of PCI failure in STEMIs: A systematic review

BACKGROUND

When feasible, primary percutaneous coronary intervention (PCI) is the definitive intervention for ST-elevation myocardial infarction (STEMI). However, cardiac tissue reperfusion is not always achievable after opening the infarct-related artery. Studies have investigated associating factors and scoring for the "no-reflow" phenomenon. This paper aims to systematically establish the predictive values of total ischemic time and patient age as factors of coronary no-reflow in patients undergoing primary PCI.

METHODS

A systematic search was performed using EBSCOhost, including CINAHL Complete, Academic Search Premier, MEDLINE with Full Text, Cochrane Central Register of Controlled Trials, and Cochrane Database of Systematic Reviews. Search results were compiled utilizing Zotero reference manager and exported to Covidence.org for screening, selection, and data extraction by two independent reviewers. The Newcastle-Ottawa Quality Assessment Scale for Cohort Studies was used to evaluate the eight selected studies.

RESULTS

The initial search resulted in 367 articles, with eight meeting the inclusion criteria with a total of 7060 participants. Our systematic review demonstrated that for patients older than 60 years, the odds of the no-reflow phenomenon increased 1.53- 2.53 times. Additionally, patients with increased total ischemic time had 1.147- 4.655 times the odds of no-reflow incidence.

CONCLUSIONS

Patients older than 60 years with a total ischemic time >4-6 h are at higher risk of PCI failure due to the no-reflow phenomenon. Therefore, new guidelines and more research to prevent and treat this physiologic occurrence are essential to improve coronary reperfusion after primary PCI.

Investigating the association between the COVID-19 vaccination and incident gastrointestinal symptomology: A comprehensive dataset

The coronavirus disease of 2019 (COVID-19) pandemic created a variety of symptoms from mild to acute in the general population. Additional disease burden was experienced in high-risk populations, such as older adults, people with disabilities or overweight, those from racial and ethnic minority groups, and patients with cancer, chronic kidney, lung or liver disease, or diabetes. Although it is well-known that SARS-CoV-2 mostly affects the respiratory tract, studies have revealed the presence of gastrointestinal (GI) symptoms in those patients diagnosed with COVID-19. The best protection against infection is through receipt of the COVID-19 vaccine, which is associated with a low incidence of adverse events. However, there is limited research on the lesser-known side effects experienced following receipt of the COVID-19 vaccination, amongst healthy and special needs populations. This study investigated the association between the COVID-19 vaccination and, when it occurred, infection, and resulting gastrointestinal (GI) symptomology, focusing on both the general population and on those previously diagnosed with GI disorders, Irritable Bowel Syndrome (IBS) and Inflammatory Bowel Disease (IBD). Through a short, anonymous survey, 215 participants were assessed for acute onset of GI issues and/or worsening of pre-existing GI issues following the receipt of one or more COVID-19 vaccine doses and following contraction of COVID-19 itself, when applicable. All analyses were performed using SAS version 9.4, and prior to study initiation, the study protocol was reviewed and approved as exempt by the Stamford Hospital's Institutional Review Board of record. Data analysis included reporting of demographic variables as well as descriptive statistics regarding side effects experienced after receipt of the COVID-19 vaccine, as well as after contracting COVID-19, if it occurred. To assess for statistically significant differences between the groups, ANOVA was conducted for each survey item. Reporting of results consisted of the mean and standard deviation within each of the groups, and an omnibus p-value less than 0.05 (p <0.05) was considered statistically significant. For the purposes of this report, a greater than 0.50 response difference between highest and lowest mean value will be presented. In the event of a statistically significant omnibus p-value, the Scheffe test was used as the post-hoc procedure. The database created through this research demonstrates the prevalence of post-COVID-19 vaccination side effects and can serve as preliminary data for gaining a better understanding of how both general and populations with a higher disease burden are being affected by the COVID-19 vaccine, booster doses, and incident COVID-19 infection in vaccinated individuals.

Evaluation of a pain management program for patients with median arcuate ligament syndrome

Objectives

Median arcuate ligament syndrome is a complex disorder potentially caused by variation in the position of the median arcuate ligament. Symptomology involves chronic abdominal pain, nausea, and malnourishment. Pain management modalities and short-term outcomes for patients undergoing operative surgery for median arcuate ligament syndrome have yet to be fully evaluated. Our hospital implemented a pain management consultation program in 2017 focused on perioperative pain management. The objective of this study is to assess if the introduction of a pain management consultation program concurrent with median arcuate ligament syndrome surgery impacts patient outcomes and post-operative pain management strategies in these patients.

Methods

De-identified data was collected retrospectively from our hospital's electronic medical records system, identifying median arcuate ligament syndrome patients and using International Classification of Diseases (ICD) and Current Procedural Terminology (CPT) codes from September 2017 to August 2021. Patients were grouped into the "consultation" cohort if they had scheduled and attended a pre-operative pain consultation. Pre-operative and discharge medications, pain scores, and demographics were collected to evaluate if the initiative impacted outcomes.

Results

Median arcuate ligament syndrome patients who had a pre-operative pain management consultation had higher rates of pre-operative opioid (35.5%; p = 0.01) and non-opioid use (60.7%; p < 0.001). Patients without a pre-operative consultation that did not use opioids pre-operatively were more likely to be discharged on one or more opioids. Differences were also found for psychiatric medication at discharge (p < 0.001) with patients receiving pain consultation indicating higher percentages of use.

Conclusion

Special consideration on prescribing pain medication should be part of discharge planning for median arcuate ligament syndrome patients. Addition of a pain management consultation can aid in these decisions.

Home Oxygen and Monitoring for COVID-19 Patients: A Multidisciplinary Team Approach

Introduction

During the initial COVID-19 pandemic peak, Stamford Hospital implemented a home oxygen program (HOP) to create a comprehensive, multi-disciplinary outpatient initiative without sacrificing a safe discharge. Primary care physicians monitored program participants, whose only indication for remaining admitted was an oxygen requirement. We retrospectively examined participant co-morbidities and outcomes, including death and readmission rates to evaluate HOP safety.

Methods

A retrospective analysis of program participants discharged between April 2020-Janurary 2021 was performed. Variables included demographics, oxygen requirement, days enrolled in the HOP, and major comorbidities such as cardiovascular disease (CVD), diabetes (DM), hypertension (HTN), obesity, chronic kidney disease, malignancies and underlying chronic obstructive pulmonary disease (COPD).

Results

Among the 138 HOP participants, ages ranged from 23 to 96 (Mean 65.5), with 47.1% female and 52.9% male. The most represented ethnicity included White (48.6%), Hispanic (29.7%), and Black (15.2%). Patients' average time in the HOP was 19 days, requiring an average of 1.7 L/min of home oxygen. Thirteen patients (9.4%) were readmitted to the hospital with 2.9% secondary to worsening COVID-19 hypoxia, but no deaths occurred at home. A significant relationship was found between age and highest home oxygen need. Patients with COPD, HTN, and DM had significantly higher oxygen requirements (P-value <0.05).

Conclusion

Increasing age, underlying COPD, HTN, and DM were associated with higher oxygen requirements in participants. Given limited availability of hospital beds, and no occurrences of death at home, Stamford Hospital HOP safely helped provide care for sicker patients and enhanced resource allocation.

Clinical Characteristics, Racial Inequities, and Outcomes in Patients with Breast Cancer and COVID-19: A COVID-19 and Cancer Consortium (CCC19) Cohort Study

Background

Limited information is available for patients with breast cancer (BC) and coronavirus disease 2019 (COVID-19), especially among underrepresented racial/ethnic populations.

Methods

This is a COVID-19 and Cancer Consortium (CCC19) registry-based retrospective cohort study of females with active or history of BC and laboratory-confirmed severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection diagnosed between March 2020 and June 2021 in the US. Primary outcome was COVID-19 severity measured on a five-level ordinal scale, including none of the following complications, hospitalization, intensive care unit admission, mechanical ventilation, and all-cause mortality. Multivariable ordinal logistic regression model identified characteristics associated with COVID-19 severity.

Results

1,383 female patient records with BC and COVID-19 were included in the analysis, the median age was 61 years, and median follow-up was 90 days. Multivariable analysis revealed higher odds of COVID-19 severity for older age (aOR per decade, 1.48 [95% CI, 1.32 - 1.67]); Black patients (aOR 1.74; 95 CI 1.24-2.45), Asian Americans and Pacific Islander patients (aOR 3.40; 95 CI 1.70 - 6.79) and Other (aOR 2.97; 95 CI 1.71-5.17) racial/ethnic groups; worse ECOG performance status (ECOG PS ≥2: aOR, 7.78 [95% CI, 4.83 - 12.5]); pre-existing cardiovascular (aOR, 2.26 [95% CI, 1.63 - 3.15])/pulmonary comorbidities (aOR, 1.65 [95% CI, 1.20 - 2.29]); diabetes mellitus (aOR, 2.25 [95% CI, 1.66 - 3.04]); and active and progressing cancer (aOR, 12.5 [95% CI, 6.89 - 22.6]). Hispanic ethnicity, timing and type of anti-cancer therapy modalities were not significantly associated with worse COVID-19 outcomes. The total all-cause mortality and hospitalization rate for the entire cohort was 9% and 37%, respectively however, it varied according to the BC disease status.

Conclusions

Using one of the largest registries on cancer and COVID-19, we identified patient and BC related factors associated with worse COVID-19 outcomes. After adjusting for baseline characteristics, underrepresented racial/ethnic patients experienced worse outcomes compared to Non-Hispanic White patients.

Opportunistic salpingectomy during robotic sacrocolpopexy: Data to support a widely accepted practice

While surgical outcomes of prophylactic salpingectomy as an ovarian cancer risk reducing measure at the time of hysterectomy for benign indications has already been studied, data has traditionally been extrapolated to surgery for prolapse repair. A retrospective chart review was performed from medical records of patients who had undergone a sacrocolpopexy for pelvic organ prolapse. Variables collected included operation duration, length of hospital stay, readmission within 31 days, estimated blood loss (EBL), number and size of incisions, as well as narcotic use during hospitalization. Additional procedures performed at the time of operation including vaginal or laparoscopic hysterectomy, transobturator sling, anterior or posterior colporrhaphy, cystoscopy, and robotic ventral mesh rectopexy were collected as potential confounding variables. In addition, data to allow examination of pathology results of all fallopian tubes was collected to determine the proportion of pre-malignant and malignant pathology results. Statistical analyses were performed using SAS version 8. Two cohorts were created: (1) Patients who underwent adnexal surgery (bilateral salpingectomy or salpingoopherectomy) at time of the sacrocolpopexy and (2) Patients who underwent a sacrocolpopexy without adnexal surgery. Comparisons were performed with chi-square analysis for discrete variables and group t-tests for continuous level data. Narcotics administered during the immediate post-operative period until discharge was collected for each patient and converted to morphine milligram equivalents (MME) via multiplying the administered dose by the CDC established evidence-based conversion factor. Analysis of covariance (ANCOVA) as well as logistic regression was used to control for confounding variables, including the additional procedures patients had during their operation. An omnibus p-value of 0.05 was used to determine statistical significance for all tests. Due to the exploratory nature of this analysis, there were no corrections applied for multiple comparisons. This data can be used as a basis for researchers to build upon when assessing ovarian cancer primary prevention strategies and associated treatment modalities.

Interplay of Immunosuppression and Immunotherapy Among Patients With Cancer and COVID-19

Importance

Cytokine storm due to COVID-19 can cause high morbidity and mortality and may be more common in patients with cancer treated with immunotherapy (IO) due to immune system activation.

Objective

To determine the association of baseline immunosuppression and/or IO-based therapies with COVID-19 severity and cytokine storm in patients with cancer.

Design, Setting, and Participants

This registry-based retrospective cohort study included 12 046 patients reported to the COVID-19 and Cancer Consortium (CCC19) registry from March 2020 to May 2022. The CCC19 registry is a centralized international multi-institutional registry of patients with COVID-19 with a current or past diagnosis of cancer. Records analyzed included patients with active or previous cancer who had a laboratory-confirmed infection with SARS-CoV-2 by polymerase chain reaction and/or serologic findings.

Exposures

Immunosuppression due to therapy; systemic anticancer therapy (IO or non-IO).

Main Outcomes and Measures

The primary outcome was a 5-level ordinal scale of COVID-19 severity: no complications; hospitalized without requiring oxygen; hospitalized and required oxygen; intensive care unit admission and/or mechanical ventilation; death. The secondary outcome was the occurrence of cytokine storm.

Results

The median age of the entire cohort was 65 years (interquartile range [IQR], 54-74) years and 6359 patients were female (52.8%) and 6598 (54.8%) were non-Hispanic White. A total of 599 (5.0%) patients received IO, whereas 4327 (35.9%) received non-IO systemic anticancer therapies, and 7120 (59.1%) did not receive any antineoplastic regimen within 3 months prior to COVID-19 diagnosis. Although no difference in COVID-19 severity and cytokine storm was found in the IO group compared with the untreated group in the total cohort (adjusted odds ratio [aOR], 0.80; 95% CI, 0.56-1.13, and aOR, 0.89; 95% CI, 0.41-1.93, respectively), patients with baseline immunosuppression treated with IO (vs untreated) had worse COVID-19 severity and cytokine storm (aOR, 3.33; 95% CI, 1.38-8.01, and aOR, 4.41; 95% CI, 1.71-11.38, respectively). Patients with immunosuppression receiving non-IO therapies (vs untreated) also had worse COVID-19 severity (aOR, 1.79; 95% CI, 1.36-2.35) and cytokine storm (aOR, 2.32; 95% CI, 1.42-3.79).

Conclusions and Relevance

This cohort study found that in patients with cancer and COVID-19, administration of systemic anticancer therapies, especially IO, in the context of baseline immunosuppression was associated with severe clinical outcomes and the development of cytokine storm.

Trial Registration

ClinicalTrials.gov Identifier: NCT04354701.

Augmentation of a Hospital Incident Command System to Support Continued Waves of the COVID-19 Pandemic

Stamford Hospital (SH) is a 305 bed Level II Trauma center located in Fairfield County, the epicenter of the coronavirus disease 2019 (COVID-19) pandemic in Connecticut. The COVID-19 pandemic was a fast paced, rapidly evolving crisis, presenting our leadership team with unique challenges related to resource availability, patient care, and staff safety. The existing Hospital Incident Command System (HICS) was activated in March 2020 to coordinate our operational emergency management planning, response, and recovery capability for this unplanned event. Although HICS lays the groundwork for hospital preparations and protocol implementation, it is not designed to withstand prolonged crisis circumstances. Given the conditions that the COVID-19 pandemic presented, the possibility for future waves became an impending reality, prompting the need for a long-term solution. To establish guidelines that promoted balance between necessary preparations in the case of additional surges of the pandemic and concurrent resumption then maintenance of routine hospital operations, the SH COVID-19 Playbook was created. The Playbook, presented here, is arranged in accordance with the evidence-based 4 S’s (Space, Staff, Systems, and Stuff) strategic critical care planning framework, to address surge capacity management within our hospital’s four main patient care areas and additional supportive services. Through feedback from frontline caregivers and leaders within SH, the Playbook captures our experience, best practices, and insight acquired during the first wave of the pandemic. Established with the intentions of equipping leadership and staff globally, guidelines are presented to aid in the navigation of future pandemic surges and successfully care for COVID-19 patients, ensure staff safety, allow for normal services to operate, and provide optimal communication and support for the community, patients, and staff.

Effects of the COVID-19 Crisis on Resident Well-Being in a Community Teaching Hospital

OBJECTIVES

The coronavirus disease 2019 (COVID-19) pandemic has been an unexpected crisis that continues to challenge the medical community at large. Healthcare environments have been forced to change dramatically, including for medical residents, who are vital members of the innovative emergency response teams. Articles have previously been published on the effects of crises on the well-being of healthcare practitioners; however, there is a paucity of literature targeting medical residents' experiences and general wellness during devastating events. The objective of our study aimed at understanding the emotional impact of the COVID-19 pandemic on residents' stress, academics, and support systems.

METHODS

An anonymous, voluntary Likert scale questionnaire was sent via SurveyMonkey to Internal Medicine and Family Medicine residents in July 2020. Questions focused on residents' mood; stress levels; sense of support; and academics before, during, and immediately after the first surge of COVID-19 at our hospital between March 13 and June 15, 2020.

RESULTS

Residents felt sad, stressed, and overworked during the first wave, as opposed to feelings of neutrality and happiness before and immediately after. Levels of concern for personal and loved ones' safety were significantly increased during and after our first wave. The impact on educational training was rated as neutral. Residents noted that institutional support could be improved by the provision of wellness activities and sponsored social events.

CONCLUSIONS

This study provides insight on resident well-being during the initial months of the pandemic and identifies areas that could be improved. Our results demonstrated that the pandemic affected many aspects of residents' well-being and education, and the lessons learned can help guide healthcare institutions when implementing wellness activities for trainees during subsequent crises.

Postoccupancy Evaluation of a Neighborhood Concept Redesign of an Acute Care Nursing Unit in a Planetree Hospital

OBJECTIVE

A comparative study was undertaken to survey nurses working in an acute care nursing unit before and after moving to a new hospital to investigate the impact of a nursing unit designed utilizing Planetree build criteria.

BACKGROUND

The physical and emotional demands of frontline practitioners is a serious concern for patient safety and staff retention as the environmental design of nursing units can influence human errors from fatigue and interruption.

METHOD

A pre-move survey was conducted with acute care nurses in a conventional design nursing unit who were moving to a new facility. After the move to the new hospital design, the same survey was readministered to obtain comparative performance information. Qualitative responses were analyzed for triangulation with survey responses. Hospital Consumer Assessment of Healthcare Providers and Systems (HCAHPS) and Press Ganey scores were collected over a 5-year period.

RESULTS

There were statistically significant improvements for most of the survey questions, especially for work efficiency and productivity, the design of the patient room and of support spaces, the information systems, and the environmental conditions. There were statistically significant improvements in the HCHAPS and Press Ganey survey questions.

CONCLUSIONS

The postoccupancy survey showed statistically significant improvements in most of the concerns highlighted in the pre-move survey and significant improvements in the workflow and overall satisfaction of nurses. Press Ganey results revealed all but five domains fell in the significantly improved category.

Temperature Equilibration due to Charge State Fluctuations in Dense Plasmas

The charge states of ions in dense plasmas fluctuate due to collisional ionization and recombination. Here, we show how, by modifying the ion interaction potential, these fluctuations can mediate energy exchange between the plasma electrons and ions. Moreover, we develop a theory for this novel electron-ion energy transfer mechanism. Calculations using a random walk approach for the fluctuations suggest that the energy exchange rate from charge state fluctuations could be comparable to direct electron-ion collisions. This mechanism is, however, predicted to exhibit a complex dependence on the temperature and ionization state of the plasma, which could contribute to our understanding of significant variation in experimental measurements of equilibration times.

Demonstration of Geometric Effects and Resonant Scattering in the X-Ray Spectra of High-Energy-Density Plasmas

In a plasma of sufficient size and density, photons emitted within the system have a probability of being reabsorbed and reemitted multiple times-a phenomenon known in astrophysics as resonant scattering. This effect alters the ratio of optically thick to optically thin lines, depending on the plasma geometry and viewing angle, and has significant implications for the spectra observed in a number of astrophysical scenarios, but has not previously been studied in a controlled laboratory plasma. We demonstrate the effect in the x-ray spectra emitted by cylindrical plasmas generated by high power laser irradiation, and the results confirm the geometrical interpretation of resonant scattering.

Compassionate Use of Remdesivir in Pregnant Women with Severe Covid-19

Background

Remdesivir is efficacious for severe coronavirus disease 2019 (COVID-19) in adults, but data in pregnant women are limited. We describe outcomes in the first 86 pregnant women with severe COVID-19 who were treated with remdesivir.

Methods

The reported data span 21 March to 16 June 2020 for hospitalized pregnant women with polymerase chain reaction–confirmed severe acute respiratory syndrome coronavirus 2 infection and room air oxygen saturation ≤94% whose clinicians requested remdesivir through the compassionate use program. The intended remdesivir treatment course was 10 days (200 mg on day 1, followed by 100 mg for days 2–10, given intravenously).

Results

Nineteen of 86 women delivered before their first dose and were reclassified as immediate “postpartum” (median postpartum day 1 [range, 0–3]). At baseline, 40% of pregnant women (median gestational age, 28 weeks) required invasive ventilation, in contrast to 95% of postpartum women (median gestational age at delivery 30 weeks). By day 28 of follow-up, the level of oxygen requirement decreased in 96% and 89% of pregnant and postpartum women, respectively. Among pregnant women, 93% of those on mechanical ventilation were extubated, 93% recovered, and 90% were discharged. Among postpartum women, 89% were extubated, 89% recovered, and 84% were discharged. Remdesivir was well tolerated, with a low incidence of serious adverse events (AEs) (16%). Most AEs were related to pregnancy and underlying disease; most laboratory abnormalities were grade 1 or 2. There was 1 maternal death attributed to underlying disease and no neonatal deaths.

Conclusions

Among 86 pregnant and postpartum women with severe COVID-19 who received compassionate-use remdesivir, recovery rates were high, with a low rate of serious AEs.

Calculating Opacity in Hot, Dense Matter Using Second-Order Electron-Photon and Two-Photon Transitions to Approximate Line Broadening

Calculations of the opacity of hot, dense matter require models for plasma line broadening. However, the most general theories are too complex to calculate directly and some approximation is inevitably required. The most widely used approaches focus on the line center, where a Lorentzian shape is obtained. Here, we demonstrate that in the opposite limit, far from the line center, the opacity can be expressed in terms of second-order transitions, such as electron-photon and two-photon processes. We suggest that this insight could form the basis for a new approach to improve calculations of opacity in hot, dense matter. Preliminary calculations suggest that this approach could yield increased opacity away from absorption lines.

Single-Shot Multi-keV X-Ray Absorption Spectroscopy Using an Ultrashort Laser-Wakefield Accelerator Source

Single-shot absorption measurements have been performed using the multi-keV x rays generated by a laser-wakefield accelerator. A 200 TW laser was used to drive a laser-wakefield accelerator in a mode which produced broadband electron beams with a maximum energy above 1 GeV and a broad divergence of ≈15  mrad FWHM. Betatron oscillations of these electrons generated 1.2±0.2×10^{6}  photons/eV in the 5 keV region, with a signal-to-noise ratio of approximately 300∶1. This was sufficient to allow high-resolution x-ray absorption near-edge structure measurements at the K edge of a titanium sample in a single shot. We demonstrate that this source is capable of single-shot, simultaneous measurements of both the electron and ion distributions in matter heated to eV temperatures by comparison with density functional theory simulations. The unique combination of a high-flux, large bandwidth, few femtosecond duration x-ray pulse synchronized to a high-power laser will enable key advances in the study of ultrafast energetic processes such as electron-ion equilibration.

Production of photoionized plasmas in the laboratory with x-ray line radiation

In this paper we report the experimental implementation of a theoretically proposed technique for creating a photoionized plasma in the laboratory using x-ray line radiation. Using a Sn laser plasma to irradiate an Ar gas target, the photoionization parameter, ξ=4πF/N_{e}, reached values of order 50ergcms^{-1}, where F is the radiation flux in ergcm^{-2}s^{-1}. The significance of this is that this technique allows us to mimic effective spectral radiation temperatures in excess of 1 keV. We show that our plasma starts to be collisionally dominated before the peak of the x-ray drive. However, the technique is extendable to higher-energy laser systems to create plasmas with parameters relevant to benchmarking codes used to model astrophysical objects.

Transport coefficients of a relativistic plasma

In this work, a self-consistent transport theory for a relativistic plasma is developed. Using the notation of Braginskii [S. I. Braginskii, in Reviews of Plasma Physics, edited by M. A. Leontovich (Consultants Bureau, New York, 1965), Vol. 1, p. 174], we provide semianalytical forms of the electrical resistivity, thermoelectric, and thermal conductivity tensors for a Lorentzian plasma in a magnetic field. This treatment is then generalized to plasmas with arbitrary atomic number by numerically solving the linearized Boltzmann equation. The corresponding transport coefficients are fitted by rational functions in order to make them suitable for use in radiation-hydrodynamic simulations and transport calculations. Within the confines of linear transport theory and on the assumption that the plasma is optically thin, our results are valid for temperatures up to a few MeV. By contrast, classical transport theory begins to incur significant errors above k_{B}T∼10 keV, e.g., the parallel thermal conductivity is suppressed by 15% at k_{B}T=20 keV due to relativistic effects.

In-depth plasma-wave heating of dense plasma irradiated by short laser pulses

We investigate the mechanism by which relativistic electron bunches created at the surface of a target irradiated by a very short and intense laser pulse transfer energy to the deeper parts of the target. In existing theories, the dominant heating mechanism is that of resistive heating by the neutralizing return current. In addition to this, we find that large amplitude plasma waves are induced in the plasma in the wake of relativistic electron bunches. The subsequent collisional damping of these waves represents a source of heating that can exceed the resistive heating rate. As a result, solid targets heat significantly faster than has been previously considered. A new hybrid model, capable of reproducing these results, is described.

Dynamical friction in a relativistic plasma

The work of Spitzer on dynamical friction in a plasma [L. Spitzer, Jr., Physics of Fully Ionized Gases, 2nd ed. (Wiley, New York, 1962), Chap. 5] is extended to relativistic systems. We derive the force of dynamical friction, diffusion tensor, and test particle relaxation rates for a Maxwellian background in the same form as Trubnikov [B. A. Trubnikov, in Reviews of Plasma Physics, edited by M. A. Leontovich (Consultants Bureau, New York, 1965), Vol. 1, p. 105], enabling high-temperature laboratory and astrophysical plasmas to be modeled in a consistent manner.

Effects of large-angle Coulomb collisions on inertial confinement fusion plasmas

Large-angle Coulomb collisions affect the rates of energy and momentum exchange in a plasma, and it is expected that their effects will be important in many plasmas of current research interest, including in inertial confinement fusion. Their inclusion is a long-standing problem, and the first fully self-consistent method for calculating their effects is presented. This method is applied to "burn" in the hot fuel in inertial confinement fusion capsules and finds that the yield increases due to an increase in the rate of temperature equilibration between electrons and ions which is not predicted by small-angle collision theories. The equilibration rate increases are 50%-100% for number densities of 10(30)  m(-3) and temperatures around 1 keV.

Evidence for the dipole nature of the low-energy γ enhancement in 56Fe

The γ-ray strength function of 56Fe has been measured from proton-γ coincidences for excitation energies up to ≈11  MeV. The low-energy enhancement in the γ-ray strength function, which was first discovered in the (3He,αγ)56Fe reaction, is confirmed with the (p,p'γ)56Fe experiment reported here. Angular distributions of the γ rays give for the first time evidence that the enhancement is dominated by dipole transitions.

Measuring fast electron spectra and laser absorption in relativistic laser-solid interactions using differential bremsstrahlung photon detectors

A photon detector suitable for the measurement of bremsstrahlung spectra generated in relativistically intense laser-solid interactions is described. The Monte Carlo techniques used to extract the fast electron spectrum and laser energy absorbed into forward-going fast electrons are detailed. A relativistically intense laser-solid experiment using frequency doubled laser light is used to demonstrate the effective operation of the detector. The experimental data were interpreted using the 3-spatial-dimension Monte Carlo code MCNPX [D. Pelowitz, MCNPX User's Manual Version 2.6.0, Los Alamos National Laboratory, 2008], and the fast electron temperature found to be 125 keV.

Energy transport in short-pulse-laser-heated targets measured using extreme ultraviolet laser backlighting

The accurate characterization of thermal electron transport and the determination of heating by suprathermal electrons in laser driven solid targets are both issues of great importance to the current experiments being performed at the National Ignition Facility, which aims to achieve thermonuclear fusion ignition using lasers. Ionization, induced by electronic heat conduction, can cause the opacity of a material to drop significantly once bound-free photoionization is no longer energetically possible. We show that this drop in opacity enables measurements of the transmission of extreme ultraviolet (EUV) laser pulses at 13.9 nm to act as a signature of the heating of thin (50 nm) iron layers with a 50-nm thick parylene-N (CH) overlay irradiated by 35-fs pulses at irradiance 3×10(16) Wcm(-2). Comparing EUV transmission measurements at different times after irradiation to fluid code simulations shows that the target is instantaneously heated by hot electrons (with approximately 10% of the laser energy), followed by thermal conduction with a flux limiter of ≈0.05.

Testing quantum mechanics in non-Minkowski space-time with high power lasers and 4(th) generation light sources

A common misperception of quantum gravity is that it requires accessing energies up to the Planck scale of 10¹⁹ GeV, which is unattainable from any conceivable particle collider. Thanks to the development of ultra-high intensity optical lasers, very large accelerations can be now the reached at their focal spot, thus mimicking, by virtue of the equivalence principle, a non Minkowski space-time. Here we derive a semiclassical extension of quantum mechanics that applies to different metrics, but under the assumption of weak gravity. We use our results to show that Thomson scattering of photons by uniformly accelerated electrons predicts an observable effect depending upon acceleration and local metric. In the laboratory frame, a broadening of the Thomson scattered x ray light from a fourth generation light source can be used to detect the modification of the metric associated to electrons accelerated in the field of a high power optical laser.

Controlling fast-electron-beam divergence using two laser pulses

This Letter describes the first experimental demonstration of the guiding of a relativistic electron beam in a solid target using two colinear, relativistically intense, picosecond laser pulses. The first pulse creates a magnetic field that guides the higher-current, fast-electron beam generated by the second pulse. The effects of intensity ratio, delay, total energy, and intrinsic prepulse are examined. Thermal and Kα imaging show reduced emission size, increased peak emission, and increased total emission at delays of 4-6 ps, an intensity ratio of 10∶1 (second:first) and a total energy of 186 J. In comparison to a single, high-contrast shot, the inferred fast-electron divergence is reduced by 2.7 times, while the fast-electron current density is increased by a factor of 1.8. The enhancements are reproduced with modeling and are shown to be due to the self-generation of magnetic fields. Such a scheme could be of considerable benefit to fast-ignition inertial fusion.

Prediction of net energy gain in deuterium-beam interactions with an inertially confined plasma

It is shown that deuteron beams incident on compressed, tritium-based plasma targets can undergo beam-fusion reactions at a rate greater than Coulomb scattering for a wide range of beam energies and target temperatures. As a result, energy gains of about 5 are possible. The analysis is carried out by treating the beam ions, target ions, and the electrons as separate fluids. Essential to the attainment of high gain is the inclusion of the contribution to the fusion yield from deuterons that gain scattered energy at the expense of directed energy. The results are confirmed by Monte Carlo simulations equivalent to a Fokker-Planck treatment.

Monocytosis in BXSB mice is due to epistasis between Yaa and the telomeric region of chromosome 1 but does not drive the disease process

The BXSB murine model of systemic lupus erythematosus is differentiated from other murine models of lupus by a severe monocytosis. The recently identified Y-linked autoimmune accelerator locus, Yaa, which is fundamental to accelerated disease in male BXSB mice, is required for the monocytic phenotype in BXSB. It has also recently been shown to induce monocytosis in combination with the Nba2 locus from NZB. To dissect the genetic basis and associated pathogenicity of BXSB-related monocytosis, a panel of existing congenic mice were studied and a novel sub-congenic mouse B10.Y(BXSB).BXSB-Bxs3 was generated. Monocytosis was found to be caused by an epistatic interaction between Yaa and the telomeric region of chromosome 1, an area of approximately 30 cM. Bxs3 and Yaa together were sufficient to generate monocytosis equivalent to that of BXSB. In contrast to the NZB model, however, where monocytosis tightly correlated with autoantibody production and lethal lupus nephritis, this was not the case in BXSB. While Yaa(+) mice bearing the Bxs3 locus drive monocytosis, glomerulonephritis and autoantibody production, both autoantibody production and nephritis are discreet events that occur in the absence of the Bxs3 locus. Yaa is a pre-requisite for monocytosis, demonstrating a novel synergistic interaction between Yaa and Bxs3.

Overlapping BXSB congenic intervals, in combination with microarray gene expression, reveal novel lupus candidate genes

The BXSB mouse strain is an important model of glomerulonephritis observed in systemic lupus erythematosus (SLE). Linkage studies have successfully identified disease-susceptibility intervals; however, extracting the identity of the susceptibility gene(s) in such regions is the crucial next step. Congenic mouse strains present a defined genetic resource that is highly amenable to microarray analysis. We have performed microarray analysis using a series of chromosome 1 BXSB congenic mice with partially overlapping disease-susceptibility intervals. Simultaneous comparison of the four congenic lines allowed the identification of expression differences associated with both the initiation and progression of disease. Thus, we have identified a number of novel SLE disease gene candidates and have confirmed the identity of Ifi202 as a disease candidate in the BXSB strain. Sequencing of the promoter regions of Gas5 has revealed polymorphisms in the BXSB strain, which may account for the differential expression profile. Furthermore, the combination of the microarray results with the different phenotypes of these mice has allowed the identification of a number of expression differences that do not necessarily map to the congenic interval, but may be implicated in disease pathways.

An intronic growth hormone receptor mutation causing activation of a pseudoexon is associated with a broad spectrum of growth hormone insensitivity phenotypes

CONTEXT

Inherited GH insensitivity (GHI) is usually caused by mutations in the GH receptor (GHR). Patients present with short stature associated with high GH and low IGF-I levels and may have midfacial hypoplasia (typical Laron syndrome facial features). We previously described four mildly affected GHI patients with an intronic mutation in the GHR gene (A(-1)-->G(-1) substitution in intron 6), resulting in the activation of a pseudoexon (6Psi) and inclusion of 36 amino acids.

OBJECTIVE

The study aimed to analyze the clinical and genetic characteristics of additional GHI patients with the pseudoexon (6Psi) mutation.

DESIGN/PATIENTS

Auxological, biochemical, genetic, and haplotype data from seven patients with severe short stature and biochemical evidence of GHI were assessed.

MAIN OUTCOME MEASURES

We assessed genotype-phenotype relationship.

RESULTS

One patient belongs to the same extended family, previously reported. She has normal facial features, and her IGF-I levels are in the low-normal range for age. The six unrelated patients, four of whom have typical Laron syndrome facial features, have heights ranging from -3.3 to -6.0 sd and IGF-I levels that vary from normal to undetectable. We hypothesize that the marked difference in biochemical and clinical phenotypes might be caused by variations in the splicing efficiency of the pseudoexon.

CONCLUSIONS

Activation of the pseudoexon in the GHR gene can lead to a variety of GHI phenotypes. Therefore, screening for the presence of this mutation should be performed in all GHI patients without mutations in the coding exons.

Radiation transfer effects on the spectra of laser-generated plasmas

Experimental x-ray spectra of the H-like 2p --> 1s (Lyman-alpha) doublet have been obtained using time-integrated high-resolution spectroscopy of a constrained-flow, laser-generated aluminum plasma. These spectra show monotonic alteration of the relative intensities of the doublet components with distance from the target surface. Excellent agreement between experiment and theory is found only if the modeling includes both ion collisional rates between the fine-structure components of the level and, more importantly, the radiative pumping of one Lyman-alpha component by the other component along the direction of the major velocity gradient (i.e., perpendicular to the direction of spectra observation). Understanding radiation transfer in plasmas with high velocity gradients is important in modeling many astrophysical objects, and this experiment acts as a benchmark for such complex calculations.

Production of dense plasmas with sub-10-fs laser pulses

Close to solid state density plasmas with peak electron temperatures of about 190 eV have been generated with sub-10-fs laser pulses incident on solid targets. Extreme ultraviolet (XUV) spectroscopy is used to investigate the K shell emission from the plasma. In the spectra, a series limit for the H- and He-like resonance lines becomes evident which is explained by pressure ionization in the dense plasma. The spectra are consistent with computer simulations calculating the XUV emission and the expansion of the plasma.

Linkage analysis of the genetic determinants of T-cell IL-4 secretion, and identification of Flj20274 as a putative candidate gene

The activation-induced differentiation of naive CD4+ T cells generates functionally divergent type 1 helper T cells (Th1) or type 2 helper T cells (Th2) effector cell populations, characterized by secretion of Interferon (IFN)-gamma or Interleukin (IL)-4, respectively. Inappropriate generation of Th subsets may contribute to immune dysfunction. The decision to generate Th1/Th2 lineages is critically regulated by cytokines, such that IL-12 induces Th1 differentiation, while IL-4 induces Th2 differentiation. Genetic factors influence the pathway of Th differentiation, as displayed by the preferential generation of divergent Th populations by different inbred strains of mice. We employ two complementary genetic techniques to identify genes that regulate the default IL-4 secretion profiles of T cells from BALB/c and B6 mice. We performed a genome-wide linkage analysis of the progeny of a backcross between BALB/c and B6 mice to identify three loci, T-cell secretion of interleukin-4 (Tsi)1-3, on chromosomes 7, 19 and 15, respectively, which regulate in vitro T-cell IL-4 production. We have also employed mRNA representational difference analysis to isolate a gene, Flj20274, which is differentially expressed in T cells that secrete high levels of IL-4. Significantly, Flj20274 was mapped to the point of peak linkage within Tsi1 and is a strong candidate for Tsi1.

Charge-state distribution and Doppler effect in an expanding photoionized plasma

The charge state distributions of Fe, Na, and F are determined in a photoionized laboratory plasma using high resolution x-ray spectroscopy. Independent measurements of the density and radiation flux indicate unprecedented values for the ionization parameter xi=20-25 erg cm s(-1) under near steady-state conditions. Line opacities are well fitted by a curve-of-growth analysis which includes the effects of velocity gradients in a one-dimensional expanding plasma. First comparisons of the measured charge state distributions with x-ray photoionization models show reasonable agreement.

Taurine fluxes in insulin dependent diabetes mellitus and rehydration in streptozotocin treated rats

The effect of streptozotocin induced diabetes mellitus and rehydration on brain taurine and brain water content was studied in 4 groups of rats. Two groups of rats with diabetes mellitus were used. In one group, taurine and brain water content were determined following induction of diabetes for one week. In the second group, diabetes was induced for one week but before sacrifice, 15% of body weight of normal saline was introduced into the peritoneum, half at time 0, half 30 minutes later with sacrifice 60 minutes after the first infusion. In two groups of animals (controls), the brain taurine and water content were estimated in normal conditions and after hydration, in exactly the same way as diabetic rats. Brain taurine content was greater in diabetic rats than non-diabetic rats and there was no decrease in brain taurine content within the first hour following rehydration of the diabetic rats. Brain water content was greater in rehydrated diabetic rats than in non-rehydrated diabetic rats but there was no significant change in the brain water content after hydration of non diabetic rats. This suggested that the rapid change in water content of rehydrated diabetic rats was not accompanied by an equally rapid alteration in brain taurine content. This is consistent with the hypothesis that taurine flux could be a major factor in the aetiology of diabetic cerebral oedema. It also allows the development of possible therapeutic options which may increase outward taurine flux from brain cells. Taurine flux is increased by increasing extracellular sodium concentration or decreasing potassium concentration. Phospholemman channels may also influence taurine flux. These may have implications for the optimal method of clinical rehydration undertaken in diabetic ketoacidosis.

Clinical and endocrine characteristics in atypical and classical growth hormone insensitivity syndrome

OBJECTIVE

Classical growth hormone insensitivity syndrome (GHIS) comprises a dysmorphic phenotype, extreme short stature (height SDS < 3), normal GH and low IGF-I and IGFBP-3. Wide clinical variation is recognised with classical and atypical forms. We aimed to delineate features of the milder "atypical" GHIS phenotype, and to determine whether this correlates with milder auxological and biochemical features.

METHODS

Fifty-nine patients from a European series of 82 patients with GHIS, with strict diagnostic criteria of GHIS, were studied and assigned to classical or atypical GHIS groups according to facial phenotype, i.e. "classical" required 2 of 3 recognized GHIS features (frontal bossing, mid-facial hypoplasia and depressed nasal bridge), "atypical" required 0 or 1 of these facial features. Classical and atypical GHIS groups were compared in terms of (1) phenotypic features, including high-pitched voice, sparse hair, blue sclera, hypoglycaemia, microphallus, (2) birth length, height SDS, and (3) basal IGF-I, IGF-II, IGFBP-1, IGFBP-3, GHBP and increase in IGF-I on IGF-I generation testing.

RESULTS

Fifty patients [24 males, 26 females, aged 8.6 +/- 4.6 years (mean +/- SD)] had "classical GHIS", 9 patients (7 males, 2 females, aged 7.8 +/- 4.1 years) had "atypical GHIS", 7 with normal facies. Atypical GHIS patients had lesser height deficit (Ht SDS -4.0 +/- 1.4) compared to classical GHIS (-6.7 +/- 1.4), less reduction in IGFBP-3 SDS (atypical -5.5 +/- 3.3; classical -8.6 +/- 2.4), and more had normal GHBP (>10% binding). Other variables were also less frequent in atypical GHIS patients: high-pitched voice 11% (70% classical), sparse hair 11% (42% classical), blue sclera 0% (38% classical), hypoglycaemia 11% (42% classical), and microphallus 14% (1 of 7 males), compared to 79% of classical (19 of 24 males).

CONCLUSIONS

Atypical GHIS patients, with relatively normal facial appearance, demonstrate less height defect and biochemical abnormalities compared to classical patients. GH insensitivity may be present in children with short stature and an otherwise normal appearance.

Pseudoexon activation as a novel mechanism for disease resulting in atypical growth-hormone insensitivity

Inherited growth-hormone insensitivity (GHI) is a heterogeneous disorder that is often caused by mutations in the coding exons or flanking intronic sequences of the growth-hormone receptor gene (GHR). Here we describe a novel point mutation, in four children with GHI, that leads to activation of an intronic pseudoexon resulting in inclusion of an additional 108 nt between exons 6 and 7 in the majority of GHR transcripts. This mutation lies within the pseudoexon (A(-1)-->G(-1) at the 5' pseudoexon splice site) and, under in vitro splicing conditions, results in inclusion of the mutant pseudoexon, whereas the wild-type pseudoexon is skipped. The presence of the pseudoexon results in inclusion of an additional 36-amino acid sequence in a region of the receptor known to be involved in homo-dimerization, which is essential for signal transduction.

Fast heating of ultrahigh-density plasma as a step towards laser fusion ignition

Modern high-power lasers can generate extreme states of matter that are relevant to astrophysics, equation-of-state studies and fusion energy research. Laser-driven implosions of spherical polymer shells have, for example, achieved an increase in density of 1,000 times relative to the solid state. These densities are large enough to enable controlled fusion, but to achieve energy gain a small volume of compressed fuel (known as the 'spark') must be heated to temperatures of about 108 K (corresponding to thermal energies in excess of 10 keV). In the conventional approach to controlled fusion, the spark is both produced and heated by accurately timed shock waves, but this process requires both precise implosion symmetry and a very large drive energy. In principle, these requirements can be significantly relaxed by performing the compression and fast heating separately; however, this 'fast ignitor' approach also suffers drawbacks, such as propagation losses and deflection of the ultra-intense laser pulse by the plasma surrounding the compressed fuel. Here we employ a new compression geometry that eliminates these problems; we combine production of compressed matter in a laser-driven implosion with picosecond-fast heating by a laser pulse timed to coincide with the peak compression. Our approach therefore permits efficient compression and heating to be carried out simultaneously, providing a route to efficient fusion energy production.

Identification of intervals on chromosomes 1, 3, and 13 linked to the development of lupus in BXSB mice

OBJECTIVE

To identify intervals containing systemic lupus erythematosus (SLE) susceptibility alleles in the BXSB strain of mice.

METHODS

We analyzed 286 (B10 x [B10 x BXSB]F1) backcross mice for a range of phenotypic traits associated with the development of SLE in BXSB mice. The mice were genotyped using 93 microsatellite markers, and the linkage of these markers to disease was studied by extreme-phenotype and quantitative trait locus analysis.

RESULTS

The disease phenotype in these backcross mice was less severe than that in BXSB mice. However, antinuclear antibody production was increased compared with the parental strain. We identified 4 areas of genetic linkage to disease on chromosome 1 (Bxs1-4), 1 on chromosome 3 (Bxs5), and another interval on chromosome 13 which were associated with various aspects of the phenotype. Bxs4 and Bxs5 are located in regions not previously linked to disease in other models of SLE.

CONCLUSION

SLE in the BXSB mouse model has a complex genetic basis and involves at least 5 distinct intervals located on chromosomes 1 and 3. There is evidence that different intervals affect particular aspects of the SLE phenotype.

Growth response to rhIGF-I 80 microg/kg twice daily in children with growth hormone insensitivity syndrome: relationship to severity of clinical phenotype

BACKGROUND

rhIGF-I has been used effectively to promote growth in growth hormone insensitivity syndrome (GHIS) in doses ranging from 40 microg/kg twice daily to 150-200 microg/kg once daily. It appears that the dose of 80 microg/kg twice daily s.c. may induce an equivalent response to higher doses with less side-effects.

OBJECTIVE

To study the efficacy and safety of rhIGF-I, 80 microg/kg twice daily s.c., in children with GHIS and to analyse the relationship of growth response to severity of phenotype.

PATIENTS AND DESIGN

Eleven prepubertal children (3 females, 8 males) with GHIS; basal GH > 2.5 microg/l, IGF-I < 50 microg/l, IGFBP-3 < - 2SD; were treated with IGF-I 80 microg/kg twice daily in a multi-centre study. The baseline characteristics of these patients were as follows (mean +/- SD): age, 7.5 +/- 2.5 years (range, 2.5-11.7 years), bone age (Tanner-Whitehouse - 2 RUS), 5.2 +/- 2.4 years (range, 2.3-9.1 years), mean height SDS, - 5.6 +/- 1.6 (range, - 3.1 to - 8.1), height velocity (HV), 3.1 +/- 1.1 cm/year (range, 1.9-4.9 cm/year). Height, HV, weight, skinfold thickness, puberty stage and bone age were measured at baseline and 6 monthly for 2 years.

RESULTS

During the first 12 months of IGF-I therapy, the mean +/- SD HV was 7.7 +/- 1.6 cm/year (range, 6.1-11.2 cm/year), the mean +/- SD increase in HV was 4.7 +/- 2.1 cm/year (range, 1.7-8.8 cm/year) and the mean +/- SD progression of bone age was 1.9 +/- 1.0 years (range, 0.8-3.8 years). Pre-treatment height SDS at the start of IGF-I therapy correlated positively with pretreatment serum IGFBP-3 SDS levels (r = 0.85; P < 0.01). There was a significant inverse correlation between gain in height SDS and pre-treatment height SDS (r = - 0.76; P < 0.01). During the 2nd 12 months of therapy, mean HV was 7.0 +/- 3.4 cm/year (range 3.8-12.4) change in height SDS from 12 to 24 months was not significantly correlated with pre-treatment height SDS. Subscapular skinfold SDS decreased significantly (P < 0.05) during the study period, whereas there was no significant change in body mass index and triceps skinfold thickness SDS. Adverse events reported in the patient group included headache (2 patients), hypoglycaemia (2 patients), papilloedema (transient, 1 patient), lipohypertrophy (5 patients) and tonsillectomy/adenoidectomy (2 patients).

CONCLUSION

This study reveals that IGF-I treatment at a dose of 80 microg/kg twice daily is effective in patients with growth hormone insensitivity syndrome. During the first 12 months of therapy, there was a significant inverse relationship between growth response to IGF-I therapy and the severity of the phenotype of growth hormone insensitivity syndrome, as measured by height SDS, at the start of therapy. Patients with a more severe clinical phenotype of growth hormone insensitivity syndrome, who also had most severe IGFBP-3 deficiency, responded better than those who were more mildly affected. An analogous situation has been shown to be the case in GH-deficient patients treated with hGH.