Clinical characteristics with inflammation profiling of long COVID and association with 1-year recovery following hospitalisation in the UK: a prospective observational study

BACKGROUND

No effective pharmacological or non-pharmacological interventions exist for patients with long COVID. We aimed to describe recovery 1 year after hospital discharge for COVID-19, identify factors associated with patient-perceived recovery, and identify potential therapeutic targets by describing the underlying inflammatory profiles of the previously described recovery clusters at 5 months after hospital discharge.

METHODS

The Post-hospitalisation COVID-19 study (PHOSP-COVID) is a prospective, longitudinal cohort study recruiting adults (aged ≥18 years) discharged from hospital with COVID-19 across the UK. Recovery was assessed using patient-reported outcome measures, physical performance, and organ function at 5 months and 1 year after hospital discharge, and stratified by both patient-perceived recovery and recovery cluster. Hierarchical logistic regression modelling was performed for patient-perceived recovery at 1 year. Cluster analysis was done using the clustering large applications k-medoids approach using clinical outcomes at 5 months. Inflammatory protein profiling was analysed from plasma at the 5-month visit. This study is registered on the ISRCTN Registry, ISRCTN10980107, and recruitment is ongoing.

FINDINGS

2320 participants discharged from hospital between March 7, 2020, and April 18, 2021, were assessed at 5 months after discharge and 807 (32·7%) participants completed both the 5-month and 1-year visits. 279 (35·6%) of these 807 patients were women and 505 (64·4%) were men, with a mean age of 58·7 (SD 12·5) years, and 224 (27·8%) had received invasive mechanical ventilation (WHO class 7-9). The proportion of patients reporting full recovery was unchanged between 5 months (501 [25·5%] of 1965) and 1 year (232 [28·9%] of 804). Factors associated with being less likely to report full recovery at 1 year were female sex (odds ratio 0·68 [95% CI 0·46-0·99]), obesity (0·50 [0·34-0·74]) and invasive mechanical ventilation (0·42 [0·23-0·76]). Cluster analysis (n=1636) corroborated the previously reported four clusters: very severe, severe, moderate with cognitive impairment, and mild, relating to the severity of physical health, mental health, and cognitive impairment at 5 months. We found increased inflammatory mediators of tissue damage and repair in both the very severe and the moderate with cognitive impairment clusters compared with the mild cluster, including IL-6 concentration, which was increased in both comparisons (n=626 participants). We found a substantial deficit in median EQ-5D-5L utility index from before COVID-19 (retrospective assessment; 0·88 [IQR 0·74-1·00]), at 5 months (0·74 [0·64-0·88]) to 1 year (0·75 [0·62-0·88]), with minimal improvements across all outcome measures at 1 year after discharge in the whole cohort and within each of the four clusters.

INTERPRETATION

The sequelae of a hospital admission with COVID-19 were substantial 1 year after discharge across a range of health domains, with the minority in our cohort feeling fully recovered. Patient-perceived health-related quality of life was reduced at 1 year compared with before hospital admission. Systematic inflammation and obesity are potential treatable traits that warrant further investigation in clinical trials.

FUNDING

UK Research and Innovation and National Institute for Health Research.

Melanocortin 1 receptor variants in an Irish population

The identification of an association between variants in the human melanocortin 1 receptor (MC1R) gene and red hair and fair skin, as well as the relation between variants of this gene and coat color in animals, suggests that the MC1R is an integral control point in the normal pigmentation phenotype. In order to further define the contribution of MC1R variants to pigmentation in a normal population, we have looked for alterations in this gene in series of individuals from a general Irish population, in whom there is a preponderance of individuals with fair skin type. Seventy-five per cent contained a variant in the MC1R gene, with 30% containing two variants. The Arg151Cys, Arg160Trp, and Asp294His variants were significantly associated with red hair (p = 0.0015, p < 0.001, and p < 0.005, respectively). Importantly, no individuals harboring two of these three variants did not have red hair, although some red-haired individuals only showed one alteration. The same three variants were also over-represented in individuals with light skin type as assessed using a modified Fitzpatrick scale. Despite these associations many subjects with dark hair/darker skin type harbored MC1R variants, but there was no evidence of any particular association of variants with the darker phenotype. The Asp294His variant was similarly associated with red hair in a Dutch population, but was infrequent in red-headed subjects from Sweden. The Asp294His variant was also significantly associated with nonmelanoma skin cancer in a U.K. population. The results show that the Arg151Cys, Arg160Trp, and Asp294His variants are of key significance in determining the pigmentary phenotype and response to ultraviolet radiation, and suggest that in many cases the red-haired component and in some cases fair skin type are inherited as a Mendelian recessive.

Elevated pyrogenic cytokines in heatstroke

STUDY OBJECTIVES

Heatstroke, characterized by hyperthermia and neurologic abnormalities, can cause shock, adult respiratory distress syndrome, and multiorgan failure culminating in death. The mediation of metabolic changes and tissue damage is not fully understood. Recent evidence suggests the involvement of endotoxin, tumor necrosis factor alpha (TNF-alpha), and interleukin 1 alpha (IL-1 alpha) and we hypothesized that other pyrogenic cytokines may be implicated.

DESIGN

Prospective analysis.

SETTING

Heatstroke Center in Makkah (Mecca), Saudi Arabia.

MEASUREMENTS AND RESULTS

We measured plasma IL-1 beta, IL-6, and interferon gamma (INF-gamma) concentrations by enzyme-linked immunosorbent assay in 28 heatstroke patients at the time of hospital admission (precooling) and after complete cooling (postcooling), and in 10 normal control subjects. We measured C-reactive protein (CRP) as a marker of acute phase response and calculated severity of illness using the simplified acute physiology score. Twenty-five male and 3 female subjects had mean (+/- SEM) rectal temperature of 41.2 +/- 0.2 degrees C. IL-6, IL-1 beta, and INF-gamma concentrations were elevated in 100 percent, 39 percent, and 50 percent of patients to (mean +/- SEM) 220 +/- 44 pg/ml, 42 +/- 14 pg/ml, and 1,180 +/- 879 pg/ml, respectively (normal control values: < 3.5 pg/ml, < 4.5 pg/ml, < 20 pg/ml). The CRP value was elevated in 72 percent of patients to 152 +/- 40 mg/L (control value: 0 to 17 mg/L). The IL-6 concentrations correlated with severity of illness (r = 0.516, p = 0.03); two patients with the highest concentrations died. There was no significant correlation between circulating levels of IL-6, IL-1 beta, INF-gamma, and temperature, or between IL-6, IL-1 beta, and CRP. Postcooling, IL-6, and IL-1 beta were still above normal control values; INF-gamma could be detected in one patient only.

CONCLUSION

Our findings of elevated circulating IL-6, IL-1 beta, and INF-gamma in the presence of acute phase response, and correlation with severity of illness, suggest that these cytokines have a role in the pathogenesis of heatstroke, which could lead to new therapeutic strategies.

Outcomes in patients with severe COVID-19 disease treated with tocilizumab: a case-controlled study

BACKGROUND

COVID-19 is an ongoing threat to society. Patients who develop the most severe forms of the disease have high mortality. The interleukin-6 inhibitor tocilizumab has the potential to improve outcomes in these patients by preventing the development of cytokine release storm.

AIMS

To evaluate the outcomes of patients with severe COVID-19 disease treated with the interleukin-6 inhibitor tocilizumab.

METHODS

We conducted a retrospective, case-control, single-center study in patients with severe to critical COVID-19 disease treated with tocilizumab. Disease severity was defined based on the amount of oxygen supplementation required. The primary endpoint was the overall mortality. Secondary endpoints were mortality in non-intubated patients and mortality in intubated patients.

RESULTS

A total of 193 patients were included in the study. Ninety-six patients received tocilizumab, while 97 served as the control group. The mean age was 60 years. Patients over 65 years represented 43% of the population. More patients in the tocilizumab group reported fever, cough and shortness of breath (83%, 80% and 96% vs. 73%, 69% and 71%, respectively). There was a non-statistically significant lower mortality in the treatment group (52% vs. 62.1%, P = 0.09). When excluding intubated patients, there was statistically significant lower mortality in patients treated with tocilizumab (6% vs. 27%, P = 0.024). Bacteremia was more common in the control group (24% vs. 13%, P = 0.43), while fungemia was similar for both (3% vs. 4%, P = 0.72).

CONCLUSION

Our study showed a non-statistically significant lower mortality in patients with severe to critical COVID-19 disease who received tocilizumab. When intubated patients were excluded, the use of tocilizumab was associated with lower mortality.

Identification of a polymorphic nucleotide in oxyR specific for Mycobacterium bovis

Automated sequence analysis of a 410-bp region of the axyR gene in 105 Mycobacterium tuberculosis complex isolates identified a polymorphic nucleotide that differentiated Mycobacterium bovis isolates from other complex members. All 29 M. bovis isolates sequenced had an adenine residue at nucleotide 285, whereas all 76 other complex isolates had a guanine residue. PCR-restriction fragment length polymorphism analysis of oxyR with restriction endonuclease AluI in an additional 255 complex isolates from widespread intercontinental sources confirmed and extended the unique association of adenine at position 285 with M. bovis isolates.

Isolation and structure elucidation of new nitrile and mustard oil glycosides from Moringa oleifera and their effect on blood pressure

Bioassay-guided analysis of an EtOH extract of Moringa oleifera leaves showing hypotensive activity led to the isolation of two nitrile glycosides, niazirin [1] and niazirinin [2], and three mustard oil glycosides, 4-[(4'-O-acetyl-alpha-L-rhamnosyloxy)benzyl]isothiocyanate [4], niaziminin A, and niaziminin B. Glycoside 2 is a new compound. Niaziminins A and B have previously been obtained from the left extract as a mixture, while compound 4 is new from this source. Structural determination was accomplished by means of spectroscopic methods including appropriate 2D nmr experiments and chemical reactions. This is the first report of the isolation of nitriles, an isothiocyanate, and thiocarbamates from the same plant species. Isothiocyanate 4 and the thiocarbamate glycosides niaziminin A and B showed hypotensive activity while nitrile glycosides 1 and 2 were found to be inactive in this regard.

Lung damage and airway remodelling in severe asthma

Severe asthma is a heterogeneous disease with substantial unmet clinical need. Airway damage and remodelling is a consequence of complex host-environment interactions and is considered to be the cardinal feature leading onto the development and persistence of airflow obstruction. In this review, we shall bring together recent insights into the causes of airway damage and remodelling that propose key roles for pathogens and mechanical damage in addition to allergens, underlying genetic susceptibility, inflammatory and structural cell interactions, and impaired resolution of damage. We shall consider the consequences of airway remodelling in terms of airway geometry, mechanics and clinical expression of disease. Understanding the causes and consequences of airway damage and remodelling will shed light upon the structure-function relationships required to begin to unravel the complexity of severe asthma and will enable us to target current and novel therapies as we begin to move towards realizing personalized medicine.

Granulocyte-macrophage colony-stimulating factor expression in induced sputum and bronchial mucosa in asthma and COPD

Background:

Granulocyte–macrophage colony-stimulating factor (GM-CSF) has been implicated as an important mediator in the pathogenesis of asthma and chronic obstructive pulmonary disease (COPD). However, the expression of GM-CSF and its receptor in airway samples in asthma and COPD across disease severity needs to be further defined.

Methods:

Sputum GM-CSF was measured in 18 control subjects, 45 subjects with asthma and 47 subjects with COPD. Enumeration of GM-CSF+ cells in the bronchial submucosa and airway smooth muscle bundle was performed in 29 control subjects, 36 subjects with asthma and 10 subjects with COPD.

Results:

The proportion of subjects with measurable GM-CSF in the sputum was raised in those with moderate (7/14) and severe (11/18) asthma, and in those with COPD GOLD (Global Initiative for Chronic Obstructive Lung Disease) stage II (7/16), III (8/17) and IV (7/14) compared with controls (1/18) and those with mild asthma (0/13); p = 0.001. The sputum GM-CSF concentration was correlated with the sputum eosinophilia in subjects with moderate to severe asthma (r_s = 0.41; p = 0.018). The median (interquartile range) GM-CSF+ and GM-CSFR+ cells/mm² of submucosa was increased in severe asthma (1.4 (3.0) and 2.1 (8.4)) compared with those with mild to moderate asthma (0 (2.5) and 1.1 (5)) and healthy controls (0 (0.5) and 0 (1.6)), (p = 0.004 and p = 0.02, respectively).

Conclusions:

The findings support a potential role for GM-CSF in asthma and COPD and suggest that overexpression of GM-CSF in sputum and the bronchial mucosa is a particular feature of severe asthma.

Naga chilli: a potential source of capsaicinoids with broad-spectrum ethnopharmacological applications

Capsicum species are not only cultivated as vegetable and condiment crops but are also incorporated into a number of medicinal preparations in the ancient literature around the world. 'Naga chilli' or 'Bhoot Jolokia' (Capsicum chinense Jacq.) is a chilli variety indigenous to the northeast region of India and has been recognized as the hottest chilli in the world. It has also been used conventionally in treating various human ailments since time immemorial by the indigenous people of the northeast India. Despite being an important crop of the northeast India, the information on the biology and cultivation of Naga chilli is very scanty and scattered. The present article reviews the scientific literature on above aspects with particular emphasis on identifying the key regional issues which need to be addressed urgently by the policy makers in order to harness its potential as an important source of capsaicinoids. Further, an attempt has been made to collate the potential of capsaicinoids in various ethnopharmacological applications such as pain therapy, body temperature regulation, anti-obesity treatments, anticancer therapy and as antioxidant and antimicrobial agent. We anticipate that this literature analysis of traditional medicinal uses and experimental trials of Capsicum using modern scientific approaches shall provide a basis for suggesting important areas where sincere research efforts are warranted to bridge the gap between traditional medicinal knowledge and modern biomedical knowledge.

Reducing ventilator-associated pneumonia rates through a staff education programme

Ventilator-associated pneumonia (VAP) is the most common nosocomial infection in patients on mechanical ventilation and results in increases in mortality, prolonged hospitalization and costs. Preventive measures for VAP are well-documented and evidence-based, yet remain poorly implemented in most intensive care units. We undertook an observational pre and post-intervention study to assess whether an educational programme focusing on preventive practices for VAP could reduce the incidence. Six hundred and seventy-seven adult patients, mechanically ventilated for >48 h were included in the study population. An evidence-based guideline for preventive practices at the bedside was developed and disseminated to the intensive care unit staff. VAP incidence rates before and after implementation of the educational programme were compared. VAP infection rates reduced by 51%, from a mean of 13.2+/-1.2 in the pre-intervention period to 6.5+/-1.5/1000 device days in the post-intervention period (mean difference 6.7; 95% CI: 2.9-10.4, P =0.02). A multidisciplinary educational programme geared towards intensive care unit staff can successfully reduce the incidence rates of VAP. Further studies will be needed to assess the impact on broader outcome measures such as costs or mortality.

Fully acetylated carbamate and hypotensive thiocarbamate glycosides from Moringa oleifera

Six new and three synthetically known glycosides have been isolated from the leaves of Moringa oleifera, employing a bioassay-directed isolation method on the ethanolic extract. Most of these compounds, bearing thiocarbamate, carbamate or nitrile groups, are fully acetylated glycosides, which are very rare in nature. Elucidation of the structures was made using chemical and spectroscopic methods, including 2D NMR techniques. Thiocarbamates showed hypotensive activity.

The relationship between biomarkers of fungal allergy and lung damage in asthma

BACKGROUND

Immunological biomarkers are the key to the diagnosis of allergic bronchopulmonary aspergillosis (ABPA) and fungal sensitisation, but how these relate to clinically relevant outcomes is unclear.

OBJECTIVES

To assess how fungal immunological biomarkers are related to fixed airflow obstruction and radiological abnormalities in moderate to severe asthma.

METHODS

Cross-sectional study of 431 asthmatics. Inflammatory biomarkers, lung function and an IgE fungal panel to colonising filamentous fungi, yeasts and fungal aeroallergens were measured. CT scans were scored for the presence of radiological abnormalities. Factor analysis informed the variables used in a k-means cluster analysis. Fixed airflow obstruction and radiological abnormalities were then mapped to these immunological variables in the cluster analysis.

RESULTS

329 (76.3%) subjects were sensitised to ≥ 1 fungi. Sensitisation to Aspergillus fumigatus and/or Penicillium chrysogenum was associated with a lower post-bronchodilator FEV₁ compared with those not sensitised to fungi ((73.0 (95% CI 70.2-76) vs. 82.8 (95% CI 78.5-87.2)% predicted, P < 0.001), independent of atopic status (P = 0.005)), and an increased frequency of bronchiectasis (54.5%, P < 0.001), tree-in-bud (18.7%, P < 0.001) and collapse/consolidation (37.5%, P = 0.002). Cluster analysis identified three clusters: (i) hypereosinophilic (n = 71, 16.5%), (ii) high immunological biomarker load and high frequency of radiological abnormalities (n = 34, 7.9%) and (iii) low levels of fungal immunological biomarkers (n = 326, 75.6%).

CONCLUSIONS AND CLINICAL RELEVANCE

IgE sensitisation to thermotolerant filamentous fungi, in particular A. fumigatus but not total IgE, is associated with fixed airflow obstruction and a number of radiological abnormalities in moderate to severe asthma. All patients with IgE sensitisation to A. fumigatus are at risk of lung damage irrespective of whether they meet the criteria for ABPA.

Airway wall geometry in asthma and nonasthmatic eosinophilic bronchitis

BACKGROUND

Variable airflow obstruction and airway hyperresponsiveness (AHR) are features of asthma, which are absent in nonasthmatic eosinophilic bronchitis (EB). Airway remodelling is characteristic of both conditions suggesting that remodelling and airway dysfunction are disassociated, but whether the airway geometry differs between asthma and nonasthmatic EB is uncertain.

METHODS

We assessed airway geometry by computed tomography (CT) imaging in asthma vs EB. A total of 12 subjects with mild-moderate asthma, 14 subjects with refractory asthma, 10 subjects with EB and 11 healthy volunteers were recruited. Subjects had a narrow collimation (0.75 mm) CT scan from the aortic arch to the carina to capture the right upper lobe apical segmental bronchus (RB1). In subjects with asthma and EB, CT scans were performed before and after a 2-week course of oral prednisolone (0.5 mg/kg).

RESULTS

Mild-moderate and refractory asthma were associated with RB1 wall thickening in contrast to subjects with nonasthmatic EB who had maintained RB1 patency without wall thickening [mean (SD) % wall area and luminal area mild-t0-moderate asthma 67.7 (7.3)% and 6.6 (2.8) mm(2)/m(2), refractory asthma 67.3 (5.6)% and 6.7 (3.4) mm(2)/m(2), healthy control group 59.7 (6.3)% and 8.7 (3.8) mm(2)/m(2), EB 61.4 (7.8)% and 11.1 (4.6) mm(2)/m(2) respectively; P < 0.05]. Airway wall thickening of non-RB1 airways generation three to six was a feature of asthma only. There was no change in airway geometry of RB1 after prednisolone. Proximal airway wall thickening was associated with AHR in asthma (r = -0.56; P = 0.02).

CONCLUSIONS

Maintained airway patency in EB may protect against the development of AHR, whereas airway wall thickening may promote AHR in asthma.

Providencia stuartii genes activated by cell-to-cell signaling and identification of a gene required for production or activity of an extracellular factor

By utilizing reporter transposons, five Providencia stuartii genes that are activated by the accumulation of self-produced extracellular signals have been identified. These genes have been designated cma for conditioned medium activated. The presence of conditioned medium from stationary-phase cultures grown in rich media resulted in the premature activation of each gene in cells at early log phase, with activation values ranging from 6- to 26-fold. Preparation of conditioned medium from an M9 salts medium and fractionation by gel filtration chromatography resulted in fractions within the included volume which activated three of the cma fusions. In addition, depending on the reporter fusion, peak activity was found in different fractions. The partially purified factors activated in a dose-dependent manner. Characterization of the factors activating the cma fusions indicated that they were stable to heat, alkali, and acid. Furthermore, for each cma fusion, factor activity was not reproduced by the addition of homoserine lactone, homocysteine thiolactone, pyruvate, Casamino Acids, or alpha-ketoglutarate. The identities of three cma genes have been determined and revealed physiological roles in amino acid biosynthesis and nutrient import. To begin to address the pathways for production of or response to the extracellular factors, we have identified a locus, aarA, that is required for the activation of four cma fusions. The AarA product was required for factor activity in extracellular supernatants, indicating a possible role in biosynthesis or export.

Bone and cartilage demonstrate changes localized to bone marrow edema-like lesions within osteoarthritic knees

OBJECTIVE

Our objective is to understand the biological and mechanical pathways linking cartilage, bone, and marrow changes in the progression of osteoarthritis (OA). The aim of the present study was to evaluate bone structure and composition within bone marrow edema-like lesion (BMEL) regions associated with knee OA.

METHODS

Tibial plateau specimens (n = 18) were collected from 10 subjects with knee OA during total knee arthroplasty (TKA). Magnetic resonance (MR) imaging was used to identify BMEL and quantify metrics of cartilage composition. Micro-computed tomography (μCT) and high-resolution peripheral quantitative computed tomography (HR-pQCT) were used to quantify density and microstructure of the subchondral trabecular bone. Fourier transform infrared (FTIR) spectroscopy was used to quantify tissue composition.

RESULTS

Trabecular bone within BMEL was higher in volume fraction, with more and thicker trabeculae that were more plate-like in structure compared to unaffected regions. BMEL trabecular tissue composition had decreased phosphate and carbonate content. Marrow infiltration by a fibrous collagen network and evidence of increased bone remodeling were present. Structural and compositional changes were specifically localized to regions underlying cartilage degradation.

CONCLUSION

These results support the paradigm of focal interactions among bone, marrow, and cartilage in the progression of knee OA. Quantitative evaluation of tissue changes and interactions may aid in the understanding of disease pathophysiology and provide imaging markers for disease progression.

Determinants of Response to Roflumilast in Severe Chronic Obstructive Pulmonary Disease. Pooled Analysis of Two Randomized Trials

RATIONALE

Roflumilast reduces exacerbations in patients with severe chronic obstructive pulmonary disease associated with chronic bronchitis and a history of exacerbations. Further characterization of patients most likely to benefit is warranted.

OBJECTIVES

Define characteristics that most robustly identify patients who derive greatest exacerbation risk reduction with roflumilast.

METHODS

Predefined, pooled analyses of REACT (Roflumilast in the Prevention of COPD Exacerbations While Taking Appropriate Combination Treatment; NCT01329029) and RE²SPOND (Roflumilast Effect on Exacerbations in Patients on Dual [LABA/ICS] Therapy; NCT01443845) multicenter, randomized, double-blind, placebo-controlled studies. The primary endpoint was rate of moderate or severe exacerbations per patient per year.

MEASUREMENTS AND MAIN RESULTS

In the overall intention-to-treat population (n = 4,287), roflumilast reduced moderate or severe exacerbations by 12.3% (rate ratio, 0.88, 95% confidence interval, 0.80-0.97; P = 0.0086) and severe exacerbations by 16.1% (0.84; 0.71-0.99; P = 0.0409) versus placebo. The reduction in moderate or severe exacerbations with roflumilast was most pronounced in patients who had been hospitalized for an exacerbation in the prior year (0.74; 0.63-0.88; P = 0.0005); had more than two exacerbations in the prior year (0.79; 0.65-0.96; P = 0.0160); or had baseline eosinophils ≥150 cells/μl (0.81; 0.71-0.93; P = 0.0020), ≥150 to <300 cells/μl (0.84; 0.71-0.98; P = 0.0282), or ≥300 cells/μl (0.77; 0.61-0.97; P = 0.0264). Similar subgroup results were noted for severe exacerbations. In patients with prior hospitalization and higher baseline blood eosinophil concentrations, roflumilast reduced moderate or severe exacerbations by 34.5% at ≥150 cells/μl (0.65; 0.52-0.82; P = 0.0003) and 42.7% at ≥300 cells/μl (0.57; 0.37-0.88; P = 0.0111) versus placebo.

CONCLUSIONS

This prespecified, pooled analysis confirms the benefit of roflumilast in decreasing exacerbations in patients with prior hospitalization for exacerbation, greater exacerbation frequency, and higher (≥150 cells/μl, ≥150 to <300 cells/μl, or ≥300 cells/μl) baseline blood eosinophil count.

Selective transcription and DNase I protection of the rat prolactin gene by GH3 pituitary cell-free extracts

Prolactin (PRL) is a member of the growth hormone gene family that is specifically expressed in the lactotroph cells of the anterior pituitary. Whole cell extracts have been prepared from cultured GH3 rat pituitary tumor cells to study lactotroph-specific expression of the rat PRL (rPRL) gene in an in vitro transcription assay. The human alpha 1-globin and Rous sarcoma virus promoters efficiently initiate transcription in both HeLa and GH3 cell extracts, whereas the rPRL promoter containing 425 base pairs of 5' flanking DNA is active only in GH3 pituitary cell-free extracts. Transcription of the rPRL gene was reconstituted in HeLa cell extracts by the addition of GH3 cell extracts. DNase I digestion of the rPRL promoter reveals two protected regions centered at positions -55 (I) and -160 (III) that are GH3 cell-specific and rPRL promoter-selective. These "footprints" overlie a highly conserved 8-base-pair motif, CCTGATAATA. By contrast, footprint II at position -125 is common to both HeLa and GH3 cell extracts and overlies a 15-base-pair sequence found in all members of the growth hormone gene family. Thus, GH3 pituitary cell-free extracts selectively transcribe the rPRL gene and contain cell-specific factors that directly interact with the rPRL promoter. These studies provide useful assays to further identify, purify, and characterize pituitary-specific transcription factors and to address the biochemical mechanisms involved in rPRL gene expression.

Inflammatory cell microlocalisation and airway dysfunction: cause and effect?

Airway inflammation is a critical feature of the airway diseases asthma and chronic obstructive pulmonary disease (COPD). There is emerging evidence that structural cells play a key role in the development and perpetuation of the inflammatory response and are pivotal in the development of the changes in the airway structures that lead to airway remodelling. To date, little attention has been given to the localisation of inflammatory cells to airway structures or the potential interactions between these intimately located cells. However, it is likely that interactions between inflammatory and structural cells in the airway contribute enormously to the pathophysiology of asthma and COPD. Indeed, recent evidence suggests that mast cells localised to the airway smooth muscle bundle may be important in the development of airway hyperresponsiveness in asthma. In the present article, the authors aim to summarise: 1) the current understanding of which inflammatory cells locate to airway structures; 2) the proposed mechanisms that may be involved in mediating this microlocalisation; 3) the possible consequences of interactions between inflammatory and structural cells; and 4) the pressing need to investigate whether modulating these interactions is beneficial in asthma and chronic obstructive pulmonary disease.

White matter imaging contributes to the multimodal diagnosis of frontotemporal lobar degeneration

OBJECTIVE

To evaluate the distribution of white matter (WM) disease in frontotemporal lobar degeneration (FTLD) and Alzheimer disease (AD) and to evaluate the relative usefulness of WM and gray matter (GM) for distinguishing these conditions in vivo.

METHODS

Patients were classified as having FTLD (n = 50) or AD (n = 42) using autopsy-validated CSF values of total-tau:β-amyloid (t-tau:Aβ(1-42)) ratios. Patients underwent WM diffusion tensor imaging (DTI) and volumetric MRI of GM. We employed tract-specific analyses of WM fractional anisotropy (FA) and whole-brain GM density analyses. Individual patient classification was performed using receiver operator characteristic (ROC) curves with FA, GM, and a combination of the 2 modalities.

RESULTS

Regional FA and GM were significantly reduced in FTLD and AD relative to healthy seniors. Direct comparisons revealed significantly reduced FA in the corpus callosum in FTLD relative to AD. GM analyses revealed reductions in anterior temporal cortex for FTLD relative to AD, and in posterior cingulate and precuneus for AD relative to FTLD. ROC curves revealed that a multimodal combination of WM and GM provide optimal classification (area under the curve = 0.938), with 87% sensitivity and 83% specificity.

CONCLUSIONS

FTLD and AD have significant WM and GM defects. A combination of DTI and volumetric MRI modalities provides a quantitative method for distinguishing FTLD and AD in vivo.

Multi-scale computational models of the airways to unravel the pathophysiological mechanisms in asthma and chronic obstructive pulmonary disease (AirPROM)

THE RESPIRATORY SYSTEM COMPRISES SEVERAL SCALES OF BIOLOGICAL COMPLEXITY: the genes, cells and tissues that work in concert to generate resultant function. Malfunctions of the structure or function of components at any spatial scale can result in diseases, to the detriment of gas exchange, right heart function and patient quality of life. Vast amounts of data emerge from studies across each of the biological scales; however, the question remains: how can we integrate and interpret these data in a meaningful way? Respiratory disease presents a huge health and economic burden, with the diseases asthma and chronic obstructive pulmonary disease (COPD) affecting over 500 million people worldwide. Current therapies are inadequate owing to our incomplete understanding of the disease pathophysiology and our lack of recognition of the enormous disease heterogeneity: we need to characterize this heterogeneity on a patient-specific basis to advance healthcare. In an effort to achieve this goal, the AirPROM consortium (Airway disease Predicting Outcomes through patient-specific computational Modelling) brings together a multi-disciplinary team and a wealth of clinical data. Together we are developing an integrated multi-scale model of the airways in order to unravel the complex pathophysiological mechanisms occurring in the diseases asthma and COPD.