Anti-C5a antibody (vilobelimab) therapy for critically ill, invasively mechanically ventilated patients with COVID-19 (PANAMO): a multicentre, double-blind, randomised, placebo-controlled, phase 3 trial

BACKGROUND

Vilobelimab, an anti-C5a monoclonal antibody, was shown to be safe in a phase 2 trial of invasively mechanically ventilated patients with COVID-19. Here, we aimed to determine whether vilobelimab in addition to standard of care improves survival outcomes in this patient population.

METHODS

This randomised, double-blind, placebo-controlled, multicentre phase 3 trial was performed at 46 hospitals in the Netherlands, Germany, France, Belgium, Russia, Brazil, Peru, Mexico, and South Africa. Participants aged 18 years or older who were receiving invasive mechanical ventilation, but not more than 48 h after intubation at time of first infusion, had a PaO2/FiO2 ratio of 60-200 mm Hg, and a confirmed SARS-CoV-2 infection with any variant in the past 14 days were eligible for this study. Eligible patients were randomly assigned (1:1) to receive standard of care and vilobelimab at a dose of 800 mg intravenously for a maximum of six doses (days 1, 2, 4, 8, 15, and 22) or standard of care and a matching placebo using permuted block randomisation. Treatment was not continued after hospital discharge. Participants, caregivers, and assessors were masked to group assignment. The primary outcome was defined as all-cause mortality at 28 days in the full analysis set (defined as all randomly assigned participants regardless of whether a patient started treatment, excluding patients randomly assigned in error) and measured using Kaplan-Meier analysis. Safety analyses included all patients who had received at least one infusion of either vilobelimab or placebo. This study is registered with ClinicalTrials.gov, NCT04333420.

FINDINGS

From Oct 1, 2020, to Oct 4, 2021, we included 368 patients in the ITT analysis (full analysis set; 177 in the vilobelimab group and 191 in the placebo group). One patient in the vilobelimab group was excluded from the primary analysis due to random assignment in error without treatment. At least one dose of study treatment was given to 364 (99%) patients (safety analysis set). 54 patients (31%) of 177 in the vilobelimab group and 77 patients (40%) of 191 in the placebo group died in the first 28 days. The all-cause mortality rate at 28 days was 32% (95% CI 25-39) in the vilobelimab group and 42% (35-49) in the placebo group (hazard ratio 0·73, 95% CI 0·50-1·06; p=0·094). In the predefined analysis without site-stratification, vilobelimab significantly reduced all-cause mortality at 28 days (HR 0·67, 95% CI 0·48-0·96; p=0·027). The most common TEAEs were acute kidney injury (35 [20%] of 175 in the vilobelimab group vs 40 [21%] of 189 in the placebo), pneumonia (38 [22%] vs 26 [14%]), and septic shock (24 [14%] vs 31 [16%]). Serious treatment-emergent adverse events were reported in 103 (59%) of 175 patients in the vilobelimab group versus 120 (63%) of 189 in the placebo group.

INTERPRETATION

In addition to standard of care, vilobelimab improves survival of invasive mechanically ventilated patients with COVID-19 and leads to a significant decrease in mortality. Vilobelimab could be considered as an additional therapy for patients in this setting and further research is needed on the role of vilobelimab and C5a in other acute respiratory distress syndrome-causing viral infections.

FUNDING

InflaRx and the German Federal Government.

Oral Sabizabulin for High-Risk, Hospitalized Adults with Covid-19: Interim Analysis

Oral Sabizabulin for High-Risk Adults with Covid-19Barnette et al. report on an interim analysis of a phase 3 randomized controlled trial of the orally available novel microtubule disruptor sabizabulin for severe Covid-19. They find a reduction in 60-day mortality from 45.1% to 20.2%.

Derivation and performance of an end-of-life practice score aimed at interpreting worldwide treatment-limiting decisions in the critically ill

Background

Limitations of life-sustaining interventions in intensive care units (ICUs) exhibit substantial changes over time, and large, contemporary variation across world regions. We sought to determine whether a weighted end-of-life practice score can explain a large, contemporary, worldwide variation in limitation decisions.

Methods

The 2015–2016 (Ethicus-2) vs. 1999–2000 (Ethicus-1) comparison study was a two-period, prospective observational study assessing the frequency of limitation decisions in 4952 patients from 22 European ICUs. The worldwide Ethicus-2 study was a single-period prospective observational study assessing the frequency of limitation decisions in 12,200 patients from 199 ICUs situated in 8 world regions. Binary end-of-life practice variable data (1 = presence; 0 = absence) were collected post hoc (comparison study, 22/22 ICUs, n = 4592; worldwide study, 186/199 ICUs, n = 11,574) for family meetings, daily deliberation for appropriate level of care, end-of-life discussions during weekly meetings, written triggers for limitations, written ICU end-of-life guidelines and protocols, palliative care and ethics consultations, ICU-staff taking communication or bioethics courses, and national end-of-life guidelines and legislation. Regarding the comparison study, generalized estimating equations (GEE) analysis was used to determine associations between the 12 end-of-life practice variables and treatment limitations. The weighted end-of-life practice score was then calculated using GEE-derived coefficients of the end-of-life practice variables. Subsequently, the weighted end-of-life practice score was validated in GEE analysis using the worldwide study dataset.

Results

In comparison study GEE analyses, end-of-life discussions during weekly meetings [odds ratio (OR) 0.55, 95% confidence interval (CI) 0.30–0.99], end-of-life guidelines [OR 0.52, (0.31–0.87)] and protocols [OR 15.08, (3.88–58.59)], palliative care consultations [OR 2.63, (1.23–5.60)] and end-of-life legislation [OR 3.24, 1.60–6.55)] were significantly associated with limitation decisions (all P < 0.05). In worldwide GEE analyses, the weighted end-of-life practice score was significantly associated with limitation decisions [OR 1.12 (1.03–1.22); P = 0.008].

Conclusions

Comparison study-derived, weighted end-of-life practice score partly explained the worldwide study’s variation in treatment limitations. The most important components of the weighted end-of-life practice score were ICU end-of-life protocols, palliative care consultations, and country end-of-life legislation.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13054-022-03971-9.

High level of HIV drug resistance informs dolutegravir roll-out and optimized NRTI backbone strategy in Mozambique

Background

HIV drug resistance (HIV-DR) is rising in sub-Saharan Africa in both ART-naive and ART-experienced patients.

Objectives

To estimate the level of acquired DR (ADR) and pre-treatment DR (PDR) across selected urban and rural sites in Southern Africa, in Mozambique.

Methods

We conducted two cross-sectional surveys among adult HIV patients (October 2017–18) assessing ADR and PDR. In the (ADR) survey, those on NNRTI-based first-line ART for ≥6 months were recruited (three sites). In the PDR survey, those ART-naive or experienced with ≥3 months of treatment interruption prior were enrolled (eight sites).

Results

Among 1113 ADR survey participants 83% were receiving tenofovir (TDF)/lamivudine (3TC)/efavirenz (EFV). The median time on ART was 4.5 years (Maputo) and 3.2 years (Tete), 8.3% (95% CI 6.2%-10.6%, Maputo) and 15.5% (Tete) had a VL ≥ 1000 copies/mL, among whom 66% and 76.4% had NNRTI+NRTI resistance, and 52.8% and 66.7% had 3TC+TDF-DR. Among those on TDF regimens, 31.1% (Maputo) and 42.2% (Tete) were still TDF susceptible, whereas 24.4% and 11.5% had TDF+zidovudine (ZDV)-DR. Among those on ZDV regimens, 25% and 54.5% had TDF+ZDV-DR. The PDR survey included 735 participants: NNRTI-PDR was 16.8% (12.0–22.6) (Maputo) and 31.2% (26.2–36.6) (Tete), with a higher proportion (≥50%) among those previously on ART affected by PDR.

Conclusions

In Mozambique, viral failure was driven by NNRTI and NRTI resistance, with NRTI DR affecting backbone options. NNRTI-PDR levels surpassed the WHO 10% ‘alert’ threshold. Replacing NNRTI first-line drugs is urgent, as is frequent viral load monitoring and resistance surveillance. Changing NRTI backbones when switching to second-line regimens may need reconsideration.

Haemodynamic monitoring and management in COVID-19 intensive care patients: an International survey

PURPOSE

To survey haemodynamic monitoring and management practices in intensive care patients with the coronavirus disease 2019 (COVID-19).

METHODS

A questionnaire was shared on social networks or via email by the authors and by Anaesthesia and/or Critical Care societies from France, Switzerland, Belgium, Brazil, and Portugal. Intensivists and anaesthetists involved in COVID-19 ICU care were invited to answer 14 questions about haemodynamic monitoring and management.

RESULTS

Globally, 1000 questionnaires were available for analysis. Responses came mainly from Europe (n = 460) and America (n = 434). According to a majority of respondents, COVID-19 ICU patients frequently or very frequently received continuous vasopressor support (56%) and had an echocardiography performed (54%). Echocardiography revealed a normal cardiac function, a hyperdynamic state (43%), hypovolaemia (22%), a left ventricular dysfunction (21%) and a right ventricular dilation (20%). Fluid responsiveness was frequently assessed (84%), mainly using echo (62%), and cardiac output was measured in 69%, mostly with echo as well (53%). Venous oxygen saturation was frequently measured (79%), mostly from a CVC blood sample (94%). Tissue perfusion was assessed biologically (93%) and clinically (63%). Pulmonary oedema was detected and quantified mainly using echo (67%) and chest X-ray (61%).

CONCLUSION

Our survey confirms that vasopressor support is not uncommon in COVID-19 ICU patients and suggests that different haemodynamic phenotypes may be observed. Ultrasounds were used by many respondents, to assess cardiac function but also to predict fluid responsiveness and quantify pulmonary oedema. Although we observed regional differences, current international guidelines were followed by most respondents.

Laparoscopic ureterocalicostomy in children: The technique and feasibility

Ureterocalicostomy is a salvage technique commonly used for failed pyeloplasties; it has also been reported as a primary procedure in ureteropelvic junction obstruction (UPJO). This video describes the technique of laparoscopic ureterocalicostomy for primary UPJO in a child with a malrotated kidney and parenchymal thinning. A 13-year-old girl with symptomatic UPJO was found to have a malrotated kidney with a high posterior insertion of the ureter. A laparoscopic dependent ureterocalicostomy over a double-J stent was performed. The postoperative course was uneventful, with excellent clinical and radiological outcomes. Literature review revealed only two reports of this laparoscopic procedure as a primary surgery in children (one with intrarenal pelvis associated to urolithiasis and the other with a malrotated kidney). Laparoscopic ureterocalicostomy is a safe and feasible option in selected cases with parenchymal thinning due to atypical UPJ anatomy or failed pyeloplasty.

Shunting in acute cerebral venous thrombosis: a systematic review

BACKGROUND AND PURPOSE

The efficacy of cerebrospinal fluid shunting to reduce intracranial hypertension and prevent fatal brain herniation in acute cerebral venous thrombosis (CVT) is unknown.

METHOD

From the International Study on Cerebral Vein and Dural Sinus Thrombosis (ISCVT) and a systematic literature review, we retrieved acute CVT patients treated only with shunting (external ventricular drain, ventriculoperitoneal or ventriculojugular shunt). Outcome was classified at 6 months and final follow-up by the modified Rankin Scale (mRS).

RESULTS

15 patients were collected (9 from the ISCVT and 6 from the review) who were treated with a shunt (external ventricular drain in 6 patients, a ventriculoperitoneal shunt in 8 patients or an unspecified type of shunt in another one). Eight patients (53.3%) regained independence (mRS 0-2), while 2 patients (13.3%) were left with a severe handicap (mRS 4-6) and 4 (26.7%) died despite treatment. Five patients with parenchymal lesions were shunted within 48 h from admission deterioration, 4 with an external ventricular drain: 2 (40%) recovered to independence, 2 (40%) had a severe handicap and 1 (20%) died. In contrast, all 3 patients with intracranial hypertension and no parenchymal lesions receiving a ventriculoperitoneal shunt later than 48 h regained independence.

CONCLUSION AND IMPLICATIONS

A quarter of acute CVT patients treated with a shunt died, and only half regained independence. With the limitation of the small number of subjects, this review suggests that shunting does not appear to be effective in preventing death from brain herniation in acute CVT. We cannot exclude that shunting may benefit patients with sustained intracranial hypertension and no parenchymal lesions.

Melanoma sentinel node biopsy and prediction models for relapse and overall survival

BACKGROUND

To optimise predictive models for sentinal node biopsy (SNB) positivity, relapse and survival, using clinico-pathological characteristics and osteopontin gene expression in primary melanomas.

METHODS

A comparison of the clinico-pathological characteristics of SNB positive and negative cases was carried out in 561 melanoma patients. In 199 patients, gene expression in formalin-fixed primary tumours was studied using Illumina's DASL assay. A cross validation approach was used to test prognostic predictive models and receiver operating characteristic curves were produced.

RESULTS

Independent predictors of SNB positivity were Breslow thickness, mitotic count and tumour site. Osteopontin expression best predicted SNB positivity (P=2.4 × 10⁻⁷), remaining significant in multivariable analysis. Osteopontin expression, combined with thickness, mitotic count and site, gave the best area under the curve (AUC) to predict SNB positivity (72.6%). Independent predictors of relapse-free survival were SNB status, thickness, site, ulceration and vessel invasion, whereas only SNB status and thickness predicted overall survival. Using clinico-pathological features (thickness, mitotic count, ulceration, vessel invasion, site, age and sex) gave a better AUC to predict relapse (71.0%) and survival (70.0%) than SNB status alone (57.0, 55.0%). In patients with gene expression data, the SNB status combined with the clinico-pathological features produced the best prediction of relapse (72.7%) and survival (69.0%), which was not increased further with osteopontin expression (72.7, 68.0%).

CONCLUSION

Use of these models should be tested in other data sets in order to improve predictive and prognostic data for patients.

Anemia and blood transfusion in a surgical intensive care unit

INTRODUCTION

Studies in intensive care unit (ICU) patients have suggested that anemia and blood transfusions can influence outcomes, but these effects have not been widely investigated specifically in surgical ICU patients.

METHODS

We retrospectively analyzed the prospectively collected data from all adult patients (>18 years old) admitted to a 50-bed surgical ICU between 1st March 2004 and 30th July 2006.

RESULTS

Of the 5925 patients admitted during the study period, 1833 (30.9%) received a blood transfusion in the ICU. Hemoglobin concentrations were < 9 g/dl on at least one occasion in 57.6% of patients. Lower hemoglobin concentrations were associated with a higher Simplified Acute Physiology Score II and Sequential Organ Failure Assessment score, greater mortality rates, and longer ICU and hospital lengths of stay. Transfused patients had higher ICU (12.5 vs. 3.2%) and hospital (18.3 vs. 6.5%) mortality rates (both p < 0.001) than non-transfused patients. However, ICU and in-hospital mortality rates were similar among transfused and non-transfused matched pairs according to a propensity score (n = 1184 pairs), and after adjustment for possible confounders in a multivariable analysis, higher hemoglobin concentrations (RR 0.97[0.95-0.98], per 1 g/dl, p < 0.001) and blood transfusions (RR 0.96[0.92-0.99], p = 0.031) were independently associated with a lower risk of in-hospital death, especially in patients aged from 66 to 80 years, in patients admitted to the ICU after non-cardiovascular surgery, in patients with higher severity scores, and in patients with severe sepsis.

CONCLUSIONS

In this group of surgical ICU patients, anemia was common and was associated with higher morbidity and mortality. Higher hemoglobin concentrations and receipt of a blood transfusion were independently associated with a lower risk of in-hospital death. Randomized control studies are warranted to confirm the potential benefit of blood transfusions in these subpopulations.

Does the time of onset of severe sepsis in a surgical intensive care unit influence mortality rates: a single-center retrospective analysis

PURPOSE

The purpose of this study was to investigate possible differences in characteristics and mortality rates between early- and late-onset severe sepsis in surgical intensive care unit (ICU) patients.

MATERIALS AND METHODS

Prospectively collected data from all adult patients (>18 years) admitted to our 50-bed surgical ICU between 1st March 2004 and 30th July 2006 were analyzed retrospectively.

RESULTS

Of 5925 patients admitted during the study period, 234 patients (3.9%) had severe sepsis: 74 (31.6%) early onset and 160 (68.4%) late onset. Respiratory infections (48.1 versus 27.0%, P = .002) and infections of unknown origin (21.9 versus 12.2%, P = .005) were recorded more frequently in patients with late-onset than in those with early-onset severe sepsis; abdominal infections were more frequent in early-onset than in late-onset severe sepsis (20.3% versus 7.5%, P = .005). Gram-positive infections were more frequent in late-onset than in early-onset severe sepsis (63.1 versus 51.4%, P = .036). The time of onset of severe sepsis was not independently associated with an increased risk of ICU (early versus late: odds ratio, 1.1; confidence interval, 0.78-0.59; P = .786) or in-hospital (early versus late: odds ratio, 0.68; 95% confidence interval, 0.36-1.29; P = .689) death.

CONCLUSIONS

Patterns of infection are different in patients with early-onset and those with late-onset severe sepsis. The time of onset of severe sepsis in surgical ICU patients has no impact on mortality. These data may be important in risk stratification and may be useful in resource allocation in the ICU.

Red blood cell transfusion in the intensive care setting: controversies amongst evidence

Anemia is a prevalent issue in intensive care units. It appears in the first days, and may continue or worsen during hospital stay. Its etiology is generally multifactorial. Red blood cell transfusion is the most common intervention for treating anemia. Approximately 12 million blood units are used for transfusions in the United States, 25% to 30% in the intensive care units. Due to reduction of transfusion infections the increased safety has allowed an expansion of clinical indications. However, transfusion therapy is associated with other adverse effects such as nosocomial infections, immunological impairment, lung injury, hemolytic reactions and higher cancer incidence. Various papers have tried to show an association between correction of anemia and mortality-morbidity, but no consensus has been reached in literature. One of the current World Health Organization's proposals is to reduce potentially unnecessary transfusions, promoting a rational transfusion attitude. The primary objective of this narrative review is to approach controversies regarding the transfusion threshold according to recent studies, and as a secondary objective, it aims to discuss iatrogenic anemia aspects and the different behaviors among intensivists on the best practices for implementation of transfusion practices. It is not within our objectives to discuss transfusion complications, although they are mentioned. A search was conducted on electronic literature databases (PubMed - Clinical Queries), and UpToDate 16.2, and additional consultation to textbooks. It became clear that transfusion practices are widely variable among intensive care units. Evidence is scarce that routine transfusion in non-hemorrhagic patients should be used in those with > 7 g/dL hemoglobin. There is no consensus on the transfusion threshold in critically ill patients. Cardiovascular disease patients seem to present a higher risk of death than non-cardiovascular patients, for any level of hemoglobin. Transfusion guided by hemoglobin levels and individual oxy-hemodynamic physiologic parameters and clinical context is apparently, the current best accepted strategy, rather than arbitrary and isolated hemoglobin correction.

Characterisation of an optical clock recovery method based on a mode-locked laser diode using spectrographic pulse measurement

As channels rates in optical networks are expected to exceed 100 Gb/s in the near future, new optical techniques for clock recovery will have to be developed for optical regeneration. This paper describes an optical clock recovery method based on a mode-locked laser diode. Experimental results show that a 42 GHz high quality optical clock can be retrieved from a 170 Gb/s OTDM data signal. Chirp transfer between the incident signal and the recovered clock signal is investigated using the SHG-FROG method. Results demonstrate that this clock recovery technique is invariant to input dispersion varying between +/-75 ps/nm, making it ideal for use in 3R regenerators.

Identification, characterization, and regulation of the canonical Wnt signaling pathway in human endometrium

Members of the Wnt family of signaling molecules are important in cell specification and epithelial-mesenchymal interactions, and targeted gene deletion of Wnt-7a in mice results in complete absence of uterine glands and infertility. To assess potential roles of the Wnt family in human endometrium, an endocrine-responsive tissue, we investigated in the proliferative and secretory phases of the menstrual cycle, endometrial expression of several Wnt ligands (Wnt-2, Wnt-3, Wnt-4, Wnt-5a, Wnt-7a, and Wnt-8b), receptors [Frizzled (Fz)-6 and low-density lipoprotein receptor-related protein (LRP)-6], inhibitors [FrpHE and Dickkopf (Dkk)-1], and downstream effectors (Dishevelled-1, glycogen synthase kinase-3beta, and beta-catenin) by RT-PCR, real-time PCR and in situ hybridization. No significant menstrual cycle dependence of the Wnt ligands (except Wnt-3), receptors, or downstream effectors, was observed. Wnt-3 increased 4.7-fold in proliferative compared with secretory endometrium (P < 0.05). However, both inhibitors showed dramatic changes during the cycle, with 22.2-fold down-regulation (P < 0.05) of FrpHE and 234.3-fold up-regulation (P < 0.001) of Dkk-1 in the secretory, compared with the proliferative phase. In situ hybridization revealed cell-specific expression of different Wnt family genes in human endometrium. Wnt-7a was exclusively expressed in the luminal epithelium, and Fz-6 and beta-catenin were expressed in both epithelium and stroma, without any apparent change during the cycle. Both FrpHE and Dkk-1 expression were restricted to the stroma, during the proliferative and secretory phase, respectively. These unique expression patterns of Wnt family genes in different cell types of endometrium and the differential regulation of the inhibitors during the proliferative and secretory phase of the menstrual cycle strongly suggest functions for a Wnt signaling dialog between epithelial and stromal components in human endometrium. Also, they underscore the likely importance of this family during endometrial development, differentiation and implantation.

Expression profiling of endometrium from women with endometriosis reveals candidate genes for disease-based implantation failure and infertility

Endometriosis is clinically associated with pelvic pain and infertility, with implantation failure strongly suggested as an underlying cause for the observed infertility. Eutopic endometrium of women with endometriosis provides a unique experimental paradigm for investigation into molecular mechanisms of reproductive dysfunction and an opportunity to identify specific markers for this disease. We applied paralleled gene expression profiling using high-density oligonucleotide microarrays to investigate differentially regulated genes in endometrium from women with vs. without endometriosis. Fifteen endometrial biopsy samples (obtained during the window of implantation from eight subjects with and seven subjects without endometriosis) were processed for expression profiling on Affymetrix Hu95A microarrays. Data analysis was conducted with GeneChip Analysis Suite, version 4.01, and GeneSpring version 4.0.4. Nonparametric testing was applied, using a P value of 0.05, to assess statistical significance. Of the 12,686 genes analyzed, 91 genes were significantly increased more than 2-fold in their expression, and 115 genes were decreased more than 2-fold. Unsupervised clustering demonstrated down-regulation of several known cell adhesion molecules, endometrial epithelial secreted proteins, and proteins not previously known to be involved in the pathogenesis of endometriosis, as well as up-regulated genes. Selected dysregulated genes were randomly chosen and validated with RT-PCR and/or Northern/dot-blot analyses, and confirmed up-regulation of collagen alpha2 type I, 2.6-fold; bile salt export pump, 2.0-fold; and down-regulation of N-acetylglucosamine-6-O-sulfotransferase (important in synthesis of L-selectin ligands), 1.7-fold; glycodelin, 51.5-fold; integrin alpha2, 1.8-fold; and B61 (Ephrin A1), 4.5-fold. Two-way overlapping layer analysis used to compare endometrial genes in the window of implantation from women with and without endometriosis further identified three unique groups of target genes, which differ with respect to the implantation window and the presence of disease. Group 1 target genes are up-regulated during the normal window of implantation but significantly decreased in women with endometriosis: IL-15, proline-rich protein, B61, Dickkopf-1, glycodelin, N-acetylglucosamine-6-O-sulfotransferase, G0S2 protein, and purine nucleoside phosphorylase. Group 2 genes are normally down-regulated during the window of implantation but are significantly increased with endometriosis: semaphorin E, neuronal olfactomedin-related endoplasmic reticulum localized protein mRNA and Sam68-like phosphotyrosine protein alpha. Group 3 consists of a single gene, neuronal pentraxin II, normally down-regulated during the window of implantation and further decreased in endometrium from women with endometriosis. The data support dysregulation of select genes leading to an inhospitable environment for implantation, including genes involved in embryonic attachment, embryo toxicity, immune dysfunction, and apoptotic responses, as well as genes likely contributing to the pathogenesis of endometriosis, including aromatase, progesterone receptor, angiogenic factors, and others. Identification and validation of selected genes and their functions will contribute to uncovering previously unknown mechanism(s) underlying implantation failure in women with endometriosis and infertility, mechanisms underlying the pathogenesis of endometriosis and providing potential new targets for diagnostic screening and intervention.

Optimal adrenergic support in septic shock due to peritonitis

BACKGROUND

The authors evaluated optimal adrenergic support using norepinephrine, dopamine, and dobutamine in a clinically relevant model of septic shock.

METHODS

Twenty-eight mature, female, anesthetized sheep (weight, 30.5 +/- 3.6 kg) underwent cecal ligation and perforation and were randomized into four groups of seven animals to be treated with norepinephrine, dopamine-norepinephrine, dobutamine-norepinephrine, or no adrenergic agent. In all groups, lactated Ringer's solution was administered to restore cardiac filling pressures to baseline. In the norepinephrine group, norepinephrine (0.5-5 microg. kg(-1). min(-1)) was titrated to maintain mean arterial pressure between 75-85 mmHg. In the dopamine-norepinephrine group, dopamine was given first, and norepinephrine was added only when mean arterial pressure remained below 75 mmHg despite the infusion of 20 microg. kg(-1). min(-1) dopamine. In the dobutamine-norepinephrine group, dobutamine was started at the same time as norepinephrine and titrated up to 20 microg. kg(-1). min(-1) to get a 15% increase in cardiac output.

RESULTS

The dobutamine-norepinephrine group had greater cardiac output; superior mesenteric blood flow, oxygen delivery (Do(2)), and oxygen consumption ([OV0312]o(2)); and lower blood lactate concentration and partial pressure of carbon dioxide (Pco(2)) gap than the controls did. Cumulative urine output was significantly higher in the dobutamine-norepinephrine group than in the other groups. Survival time was significantly longer in the dobutamine-norepinephrine (24 +/- 4 h), dopamine- norepinephrine (24 +/- 6 h), and norepinephrine (20 +/- 1 h) groups than the control group (17 +/- 2 h; P < 0.05 vs. other groups), and significantly longer in the combined dopamine-norepinephrine and dobutamine-norepinephrine groups (24 +/- 5 h) than in the norepinephrine alone group (P < 0.05). Histologic examination of lung biopsies revealed less severe lesions in the dobutamine-norepinephrine group than in the control and norepinephrine alone groups. Anatomic alterations in the lung, liver, and small intestine were less severe in the dobutamine-norepinephrine group than in the other groups.

CONCLUSIONS

In this prolonged septic shock model, association of norepinephrine with either dopamine or dobutamine resulted in the longest survival and the least severe pulmonary lesions. The combination of dobutamine with norepinephrine was associated with a better myocardial performance, greater Do(2) and [OV0312]o(2), lower blood lactate concentration and Pco(2) gap, and less anatomic injury.

Frequent microsatellite alterations in a predominantly younger age of onset breast cancer population

Microsatellite instability (MSI) and loss of heterozygosity (LOH) was investigated in paired tumour and normal tissue DNA from 108 predominantly premenopausal breast cancer patients (under age 45 years at presentation) for 25 simple repeat loci interspersed across 11 chromosomes. MSI was observed at a single locus in 69 (64%) patients; 41 of these had instability at more than one site. Greatest frequency of MSI was at loci D2S1356 (33%), D2S2739 (22%), D3S1766 (21%) and D13S796 (20%). LOH was seen at a single site in 55% of patients and at two or more sites in 27 patients with greatest frequency at D2S1356 (33%), D2S443 (19%) and D17S1299 (18%). Both mutations were found in the same patient but at different loci. Clearly, choice of loci is a determining factor in assessing genomic instability. The relatively high frequency of MSI may also reflect peculiarities of this younger patient population. Occurrence of MSI or LOH was unrelated to clinical stage, nodal status, tumour size or grade or steroid receptor status. It was independent of mutations detected in exons 5-9 of the p53 gene. There was no significant association with survival. The lack of such correlations reflects a random disabling mechanism that may equally affect genes promoting cell death as well as growth.

Global gene profiling in human endometrium during the window of implantation

Implantation in humans is a complex process that is temporally and spatially restricted. Over the past decade, using a one-by-one approach, several genes and gene products that may participate in this process have been identified in secretory phase endometrium. Herein, we have investigated global gene expression during the window of implantation (peak E2 and progesterone levels) in well characterized human endometrial biopsies timed to the LH surge, compared with the late proliferative phase (peak E2 level) of the menstrual cycle. Tissues were processed for poly(A(+)) RNA and hybridization of chemically fragmented, biotinylated cRNAs on high density oligonucleotide microarrays, screening for 12,686 genes and expressed sequence tags. After data normalization, mean values were obtained for gene readouts and fold ratios were derived comparing genes up- and down-regulated in the window of implantation vs. the late proliferative phase. Nonparametric testing revealed 156 significantly (P < 0.05) up-regulated genes and 377 significantly down-regulated genes in the implantation window. Up-regulated genes included those for cholesterol trafficking and transport [apolipoprotein (Apo)E being the most induced gene, 100-fold], prostaglandin (PG) biosynthesis (PLA2) and action (PGE2 receptor), proteoglycan synthesis (glucuronyltransferase), secretory proteins [glycodelin, mammaglobin, Dickkopf-1 (Dkk-1, a Wnt inhibitor)], IGF binding protein (IGFBP), and TGF-beta superfamilies, signal transduction, extracellular matrix components (osteopontin, laminin), neurotransmitter synthesis (monoamine oxidase) and receptors (gamma aminobutyric acid A receptor pi subunit), numerous immune modulators, detoxification genes (metallothioneins), and genes involved in water and ion transport [e.g. Clostridia Perfringens Enterotoxin (CPE) 1 receptor (CPE1-R) and K(+) ion channel], among others. Down-regulated genes included intestinal trefoil factor (ITF) [the most repressed gene (50-fold)], matrilysin, members of the G protein-coupled receptor signaling pathway, frizzled-related protein (FrpHE, a Wnt antagonist), transcription factors, TGF-beta signaling pathway members, immune modulators (major histocompatibility complex class II subunits), and other cellular functions. Validation of select genes was conducted by Northern analysis and RT-PCR using RNA from endometrial biopsies obtained in the proliferative phase and the implantation window and by RT-PCR using RNA from cultured endometrial epithelial and stromal cells. These approaches confirmed up-regulation of genes corresponding to IGFBP-1, glycodelin, CPE1-R, Dkk-1, mammaglobin, and ApoD and down-regulation for PR membrane component 1, FrpHE, matrilysin, and ITF, as with the microarray data. Cultured endometrial epithelial cells were found to express mRNAs for glycodelin, CPE-1R, Dkk-1, the gamma aminobutyric acid A receptor pi subunit, mammaglobin, matrilysin, ITF and PR membrane component 1. The expression of IGFBP-1, CPE1-R, Dkk-1, and ApoD mRNAs increased upon decidualization of stromal cells in vitro with progesterone after E2 priming, whereas FrpHE decreased, consistent with the microarray results. Overall, the data demonstrate numerous genes and gene families not heretofore recognized in human endometrium or associated with the implantation process. Reassuringly, several gene products, known to be differentially expressed in the implantation window or in secretory endometrium, were verified, and the striking regulation of select secretory proteins, water and ion channels, signaling molecules, and immune modulators underscores the important roles of these systems in endometrial development and endometrial-embryonic interactions. In addition, the current study validates using high density oligonucleotide microarray technology to investigate global changes in gene expression in human endometrium.

Ventilator associated pneumonia: risk factors and preventive measures

Ventilator-associated pneumonia (VAP) is a common nosocomial infection associated with considerable morbidity and mortality. Various risk factors for VAP have been identified and include the duration of ICU stay and of mechanical ventilation, a diagnosis of trauma, and severity of illness. Knowledge of these factors can promote early diagnosis and hence treatment. In addition to simple, but very effective, basic hygiene, different preventative strategies have been suggested, and can be divided into those that aim to limit airway colonization, and those that improve host defense mechanisms. Of the former, non-invasive ventilation is effective but not always applicable or available, nursing the patient in the semi-recumbent position is also associated with a reduced incidence of VAP but carries its own problems, stress ulcer prophylaxis remains controversial, and selective digestive decontamination is probably only relevant to certain subgroups of patients. Methods to improve host defense include early nutrition. Immunostimulatory therapies, such as interferon and granulocyte colony stimulating factor, require further research to confirm their place in the prevention or management of VAP.

A Streptomyces collinus thiolase with novel acetyl-CoA:acyl carrier protein transacylase activity

Acetyl-CoA:acyl carrier protein (ACP) transacylase (ACT) activity has been demonstrated for the 3-ketoacyl-ACP synthase III (KASIII) which initiates fatty acid biosynthesis in the type II dissociable fatty acid synthases of plants and bacteria. Several lines of evidence have indicated the possibility of ACT activity being associated with proteins other than KASIII. Using a crude extract of Streptomyces collinus, we have resolved from KASIII an additional protein with ACT activity and subsequently purified it 85-fold in five chromatographic steps. The 45 kDa protein was shown by gel filtration to have a molecular mass of 185 +/- 35 kDa, consistent with a homotetrameric structure for the native enzyme. The corresponding gene (fadA) was cloned and sequenced and shown to encode a protein with amino acid sequence homology to type II thiolases. The fadA was expressed in Escherichia coli, and the resulting recombinant FadA enzyme purified by metal chelate chromatography was shown to have both ACT and thiolase activities. Kinetic studies revealed that in an ACT assay FadA had a substrate specificity for a two-carbon acetyl-CoA substrate (K(m) 8.7 +/- 1.4 microM) but was able to use ACPs from both type II fatty acid and polyketide synthases (Streptomyces glaucescens FabC ACP, K(m) 10.7 +/- 1.4 microM; E. coli FabC ACP, K(m) 8.8 +/- 2 microM; FrenN ACP, K(m) 44 +/- 12 microM). In the thiolase assay kinetic analyses revealed similar K(m) values for binding of substrates acetoacetyl-CoA (K(m) 9.8 +/- 0.8 microM) and CoA (K(m) 10.9 +/- 1.8 microM). A Cys92Ser mutant of FadA possessed virtually unchanged K(m) values for acetoacetyl-CoA and CoA but had a greater than 99% decrease in k(cat) for the thiolase activity. No detectable ACT activity was observed for the Cys92Ser mutant, demonstrating that both activities are associated with FadA and likely involve formation of the same covalent acetyl-S-Cys enzyme intermediate. An ACT activity with ACP has not previously been observed for thiolases and in the case of the S. collinus FadA is significantly lower (k(cat) 3 min(-1)) than the thiolase activity of FadA (k(cat) 2170 min(-1)). The ACT activity of FadA is comparable to the KAS activity and significantly higher than the ACT activity, reported for a streptomycete KASIII.

Coxsackie virus A24 infection presenting as acute flaccid paralysis

Enteroviruses can cause outbreaks of acute flaccid paralysis (AFP), mimicking wild poliovirus infections. Coxsackie virus A24 has never been implicated and yet it is a virus with high outbreak potential. We describe the association of coxsackie virus A24 with AFP in East Timor.

Accumulation and elimination of trace metals in a transplantation experiment with Crassostrea rhizophorae

Oysters, Crassostrea rhizophorae, were reciprocally transplanted to two different sites: a contaminated site in the Cotegipe Channel at Aratu Bay and an uncontaminated site at Cacha-Prego, inside and outside of Todos os Santos Bay (Brazil), respectively. Trace metal accumulation was measured after 0, 15, 30, and 60 days of exposure at the contaminated site. Oysters transplanted for 60 days from the clean to the contaminated site had accumulated cadmium and lead to similar concentrations as found in the native oysters. They had also accumulated copper and zinc, but to lower levels compared to native specimens. Elimination experiments were carried out by transplanting oysters in the reverse direction. After 30 days, concentrations of cadmium and lead had decreased to levels comparable to those in the native specimen, whereas concentrations of copper and zinc did not diminish. A second elimination experiment, bringing back to Cacha-Prego oysters that had been exposed 60 days at Cotegipe Channel, indicated stronger decreases of copper and lead, but no clear changes of cadmium and zinc concentrations. The accumulation experiment with C. rhizophorae is useful to estimate trace metal bioavailability and changes in concentrations as a function of time at the contaminated site. The different results of elimination experiments in the uncontaminated site suggest different degrees of trace metal fixation after long-term and short-term accumulation periods.

Isolation of myelin basic protein-specific T cells predominantly from the memory T-cell compartment in multiple sclerosis

Myelin antigen-reactive T cells have been implicated in the pathogenesis of multiple sclerosis (MS). Myelin-reactive T cells can be isolated from control subjects as well as individuals who have MS. Experimental models of MS indicate that recently stimulated, myelin-reactive T cells have greater encephalitogenic potential than resting T cells. Activation induces changes in T-cell surface antigens that may distinguish previously stimulated, memory T cells from naive T cells. Therefore, we examined 108 myelin basic protein (MBP)-reactive T-cell lines from 7 MS and 8 control subjects to determine whether MBP-reactive T cells originated in the memory T-cell subset or in the naive subset. Isotypes of CD45 were used that designate memory or naive T cells. In subjects having MS, 84% of the MBP-reactive T cells resided in the memory T-cell subset. However, in control subjects, only 13% of MBP-specific T cells originated from the memory T-cell subset. This result suggests that a substantial proportion of MBP-reactive T cells from some individuals with MS have been previously activated in vivo. This difference provides additional support for the hypothesis that myelin antigen-specific T cells are involved in the pathogenesis of MS.

Characterization of beta-ketoacyl-acyl carrier protein synthase III from Streptomyces glaucescens and its role in initiation of fatty acid biosynthesis

The Streptomyces glaucescens fabH gene, encoding beta-ketoacyl-acyl carrier protein (beta-ketoacyl-ACP) synthase (KAS) III (FabH), was overexpressed in Escherichia coli, and the resulting gene product was purified to homogeneity by metal chelate chromatography. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis of the purified protein revealed an Mr of 37,000, while gel filtration analysis determined a native Mr of 72,000 +/- 3,000 (mean +/- standard deviation), indicating that the enzyme is homodimeric. The purified recombinant protein demonstrated both KAS activity and acyl coenzyme A (acyl-CoA):ACP transacylase (ACAT) activity in a 1:0.12 ratio. The KAS and ACAT activities were both sensitive to thiolactomycin inhibition. The KAS activity of the protein demonstrated a Km value of 3.66 microM for the malonyl-ACP substrate and an unusual broad specificity for acyl-CoA substrates, with Km values of 2.4 microM for acetyl-CoA, 0.71 microM for butyryl-CoA, and 0.41 microM for isobutyryl-CoA. These data suggest that the S. glaucescens FabH is responsible for initiating both straight- and branched-chain fatty acid biosynthesis in Streptomyces and that the ratio of the various fatty acids produced by this organism will be dictated by the ratios of the various acyl-CoA substrates that can react with FabH. Results from a series of in vivo directed biosynthetic experiments in which the ratio of these acyl-CoA substrates was varied are consistent with this hypothesis. An additional set of in vivo experiments using thiolactomycin provides support for the role of FabH and further suggests that a FabH-independent pathway for straight-chain fatty acid biosynthesis operates in S. glaucescens.

Refractive errors in young children with Down syndrome

Significant refractive errors are common among older children and adults with Down syndrome. We examined infants and children with Down syndrome to determine the prevalence of these errors at younger ages. Noncycloplegic retinoscopy was used to determine the refractive state of 92 infants and children with Down syndrome, aged 4 months to 12 years. The results for infants show a similar distribution of refractive errors in patients with Down syndrome and an age-matched control group. However, rather than a narrower distribution for the older age groups, as is the case with the controls, the distribution is wider, and the prevalence of refractive errors (including astigmatism) is higher among young children with Down syndrome than among controls. This high prevalence of refractive defects cannot be explained by the presence of strabismus or other pathologies.

In vivo and in vitro effects of thiolactomycin on fatty acid biosynthesis in Streptomyces collinus

A stable-isotope assay was used to analyze the effectiveness of various perdeuterated short-chain acyl coenzyme A (acyl-CoA) compounds as starter units for straight- and branched-chain fatty acid biosynthesis in cell extracts of Streptomyces collinus. In these extracts perdeuterated isobutyryl-CoA was converted to isopalmitate (a branched-chain fatty acid), while butyryl-CoA was converted to palmitate (a straight-chain fatty acid). These observations are consistent with previous in vivo analyses of fatty acid biosynthesis in S. collinus, which suggested that butyryl-CoA and isobutyryl-CoA function as starter units for palmitate and isopalmitate biosynthesis, respectively. Additionally, in vitro analysis demonstrated that acetyl-CoA can function as a starter unit for palmitate biosynthesis. Palmitate biosynthesis and isopalmitate biosynthesis in these cell extracts were both effectively inhibited by thiolactomycin, a known type II fatty acid synthase inhibitor. In vivo experiments demonstrated that concentrations of thiolactomycin ranging from 0.1 to 0.2 mg/ml produced both a dramatic decrease in the cellular levels of branched-chain fatty acids and a surprising three- to fivefold increase in the cellular levels of the straight-chain fatty acids palmitate and myristate. Additional in vivo incorporation studies with perdeuterated butyrate suggested that, in accord with the in vitro studies, the biosynthesis of the palmitate from butyryl-CoA decreases in the presence of thiolactomycin. In contrast, in vivo incorporation studies with perdeuterated acetate demonstrated that the biosynthesis of palmitate from acetyl-CoA increases in the presence of thiolactomycin. These observations clearly demonstrate that isobutyryl-CoA is a starter unit for isopalmitate biosynthesis and that either acetyl-CoA or butyryl-CoA can be a starter unit for palmitate biosynthesis in S. collinus. However, the pathway for palmitate biosynthesis from acetyl-CoA is less sensitive to thiolactomycin, and it is suggested that the basis for this difference is in the initiation step.

The changing prevalence of autistic disorder in a Welsh health district

A prevalence study of autistic disorder (AD) in childhood was undertaken in a Welsh health district as part of a needs' assessment exercise. The study population were all children resident in the district with dates of birth between 1977 and 1988. Children were identified after a trawl of service providers in health and education and diagnosis was confirmed at a multidisciplinary assessment. An increase in prevalence was found, an observation that has been made in other parts of the world. The increase in prevalence, whether real or administratively apparent, has major implications for service providers in health, education, and social care, in that a larger number of children are being recognised as having a triad of impairments which requires very specific interventions and support from all three agencies.

Requirement for CD4+ T cells in the gammadelta T cell proliferative response to Daudi Burkitt's lymphoma

Daudi Burkitt's lymphoma cells stimulate the proliferation of Vgamma2 Vdelta2 T cells in human peripheral blood mononuclear cells (PBMC). Transfection studies have established that the gammadelta T cell receptor is sufficient for recognition of a ligand associated with Daudi cells. Since other studies have demonstrated the need for cooperation between alphabeta T cells and Vgamma2 Vdelta2 T cells in the proliferative response to mycobacterial antigens, we used human, unfractionated PBMC and PBMC depleted of specific T cell subsets to determine whether the gammadelta T cell response to Daudi cells also requires cooperation between alphabeta and gammadelta T cells. In the current study, we demonstrate that depletion of CD4+ T cells substantially reduces the overall proliferative response of PBMC to Daudi cells and subsequent gammadelta T cell expansion. IL-2 production by PBMC in response to Daudi cells was also decreased by depletion of CD4+ T cells, but not by depletion of CD8+ or gammadelta T cells. In the CD4+ T-cell-depleted PBMC, proliferation in response to Daudi cells was restored by the addition of IL-2. These data stress the importance of cooperation between alphabeta and gammadelta T cells in the response to some complex antigens.

Induction of V gamma 2 V delta 2 T cell proliferation by activated antigen-specific CD4+ T cells and IL-2

Human gamma delta T cells respond to a wide range of ligands including some T lymphocyte cellular antigens associated with viral infection. In the present study we examined the participation of gamma delta T cells in the proliferative response that is induced in human peripheral blood mononuclear cells (PBMC) by activated, antigen-reactive, CD4+ T cells. Activated, irradiated, myelin basic protein (MBP)-specific T cells stimulate brisk proliferation when cultured with freshly isolated, autologous PBMC. Determination of the phenotype of the responding PBMC T cells revealed a prominent expansion of gamma delta T cells, principally of the V gamma 2 subset. There was only minimal proliferation of PBMC following culture with irradiated, MBP-specific T cells that had not been recently activated. However, addition of rIL-2 to cultures of PBMC and nonstimulated MBP-specific T cells restored proliferation and the expansion of the gamma delta T cells. IL-2 alone did not mediate this effect. While MBP was a convenient antigen to use in these experiments, similar gamma delta T cell expansion in vitro was noted using activated, CD4+ T cells reactive with an exogenous antigen, Candida. In additional experiments, gamma delta-enriched T cell lines and certain V gamma 2 T cell clones continued to respond to activated but not to nonstimulated, CD4+ T cells. Overall, this study suggests that V gamma 2 V delta 2 T cells may proliferate as a consequence of the activation of CD4+ T cells. At least one ligand associated with T cell activation is required in addition to IL-2.