A new definition and treatment options of allergic alveolitis

In this review, we discuss a new definition and treatment options of allergic alveolitis (AA). AA is an immune-mediated interstitial lung disease triggered by inhaled antigens, it is defined as non-fibrotic (inflammatory) and/or fibrotic, and diagnosis relies on a multidisciplinary approach using clinical, radiological and sometimes histological assessments. Treatment involves early antigen elimination and may include corticosteroids or other immunosuppressants. Prognosis varies from reversible inflammation to irreversible fibrosis. Early detection is crucial for better outcomes.

A rare case of sarcoid myelitis complicating Löfgren's syndrome

Neurosarcoidosis is a rare and serious condition. Rapid diagnosis and treatment are crucial to prevent morbidity and mortality. When neurological symptoms are not present at the time of diagnosis, CNS involvement can be undetected. We present a case of neurosarcoidosis complicating Löfgren's syndrome and discus the challenges in diagnostics and treatment, that can be encountered.

Environmental assessment of landfill gas mitigation using biocover and gas collection with energy utilisation at aging landfills

A life cycle-based environmental assessment was conducted on the mitigation of landfill gas emissions, by implementing biocover and gas collection along with energy utilisation at aging landfills. Based on recent studies about gas generation at Danish landfills, the efficiency of the mitigation technologies involved and the composition of substituted energy production, 15 scenarios were modelled using the EASETECH life cycle assessment model, through which potential environmental impacts in the category "Climate change" were calculated. In all scenarios, biocover and gas collection systems with energy utilisation led to significant environmental improvements compared to the baseline scenario with no emission mitigation action. Scenarios representing biocovers with methane oxidation efficiencies between 70 and 90 % were environmentally superior in terms of climate change impact - in comparison to scenarios with 20-30 years of gas collection and energy utilisation (collection efficiencies between 40 and 80 %). Combining gas collection with energy utilisation and the subsequent installation of a biocover saw major improvements in comparison to where only gas collection and energy utilisation were in effect. Overall, it can be concluded that a biocover under the given assumptions is environmentally more appropriate than gas collection and utilisation at aging landfills, mainly due to methane emissions escaping through the landfill cover during and after the gas collection period playing a crucial role in the latter situation. Maintaining high methane oxidation efficiency for a biocover throughout the lifetime of a landfill is vital for reducing environmental impacts.

Current best clinical practices for monitoring of interstitial lung disease

INTRODUCTION

Interstitial lung diseases (ILDs) are a heterogeneous group of inflammatory and/or fibrotic conditions with variable outcome and often a dismal prognosis. Since many ILDs are progressive in nature, monitoring of signs and symptoms of progression is essential to inform treatment decisions and patient counseling. Monitoring of ILDs is a multimodality process and includes all aspects of the disease, e.g. measurement of pulmonary function and exercise capacity, symptom registration and quality of life (QoL), imaging, comorbidities and/or involvement of other organs to assess disease activity, symptom burden, treatment effects, adverse events, the need for supportive and palliative care, and lung transplantation.

AREAS COVERED

For this narrative review, we searched the PUBMED database to identify articles relevant for monitoring ILDs, including pulmonary function tests, exercise capacity, imaging, telemedicine, symptoms, and QoL.

EXPERT OPINION

Due to the high heterogeneity of the ILDs and their disease course, an individualized multimodality approach must be applied. Future strategies include use of telemedicine for home monitoring of lung function and symptoms, use of artificial intelligence to support automatized guidance of patients, computerized evaluation of ILD changes on imaging, and new imaging tools with less radiation dosage.

[Antifibrotic therapy in other fibrotic interstitial lung diseases than idiopathic pulmonary fibrosis]

Numerous studies have shown that perioperative heparin bridging in patients treated with a vitamin K antagonist leads to an increased incidence of bleeding and so far, there is no evidence that it leads to a significant reduction in postoperative thromboembolism as summarised in this review. Prophylactic dosage of heparin is recommended after major surgery. Heparin bridging is not relevant in patients receiving a direct oral anticoagulant due to the rapid onset and offset of action of DOACs.

International multidisciplinary team discussions on the diagnosis of idiopathic non-specific interstitial pneumonia and the development of connective tissue disease

BACKGROUND

Idiopathic Non-Specific Interstitial Pneumonia (iNSIP) is a rare interstitial lung disease, diagnosed, by definition, on the basis of a multidisciplinary team discussion (MDD). Association with an autoimmune background has been suggested in iNSIP.

AIMS

To test the feasibility of conducting a multinational MDD to review the diagnosis in iNSIP cases and to estimate the emergence of connective tissue disease (CTD) during follow-up.

METHODS

Investigators from three expert centers (Denmark, Estonia and Norway) met and discussed cases of biopsy-proven iNSIP at an international MDD. The cases were previously diagnosed at a national level between 2004 and 2014. Based on clinical, radiographic and pathological data, the diagnosis of iNSIP was re-evaluated and a consensus diagnosis was made. Cases incompatible with iNSIP were excluded. Relevant data were registered comprising any development of CTD.

RESULTS

In total, 31 cases were discussed and 23 patients were included with a diagnosis of iNSIP. The mean follow-up time was 57 months. None of the patients developed CTD according to the rheumatologic criteria during the follow up period. Four patients (17.4%) met the criteria for interstitial pneumonia with autoimmune features.

CONCLUSION

We found that an international MDD was a feasible and valuable tool in the retrospective diagnostic evaluation of iNSIP. Diagnosis was changed in a statistically significant number of patients by our international MDD team. None of the patients developed CTD during follow-up.

Changes in management of idiopathic pulmonary fibrosis: impact on disease severity and mortality

Background

Idiopathic pulmonary fibrosis (IPF) is a serious interstitial lung disease (ILD) with a median survival of 3-5 years. The aim of the present study was to evaluate disease severity and survival in patients diagnosed with IPF in the era of antifibrotic therapies compared with an earlier IPF cohort.

Methods

We identified all patients with fibrotic ILD in the hospital electronic case record system between 2011 and 2016, and reviewed each case in order to identify incident patients with IPF. We used the GAP-index to compare disease severity and mortality to previous findings in patients with IPF diagnosed at our center between 2003 and 2009.

Results

260 patients were diagnosed with IPF between 2011 and 2016. Mean age was 72.6 years, 79% were male, mean forced vital capacity (FVC) was 80%, and mean diffusing capacity for carbon monoxide (DLco) was 44%. Age, FVC and DLco were significant predictors of mortality, but the presence of a typical usual interstitial pneumonia pattern on HRCT was not. Eighty percent of patients in GAP stage I received antifibrotic therapy, 73% in GAP stage II, and 29% in GAP stage III.

The median survival was four years in the 2011-2016 cohort compared with three years in the 2003-2009 cohort. The distribution of patients between GAP stages was unchanged in 2011-2016 compared with 2003-2009, (stage I 34% vs. 32%, stage II 49% vs. 48% and stage III 20% vs. 16%). One-year mortality was 13% in 2011-2016 and 26% in 2003-2009. In severe disease (GAP stage III), one-year mortality was 26% and 54%, respectively, (p=0.019).

Conclusion

Short-term mortality was significantly lower in the 2011-2016 cohort compared with 2003-2009. This improvement may be linked to changes in treatment strategies towards limited use of corticosteroids. Although early diagnosis of IPF still needs increased focus, the improvement is encouraging.

Correction to: The Burden of Sarcoidosis Symptoms from a Patient Perspective

The original version of this article unfortunately contained a mistake in coauthor's given name. The abbreviated given name "M.D." for coauthor M.D.P. Elfferich's name has been inadvertently deleted during the production process.

The Burden of Sarcoidosis Symptoms from a Patient Perspective

PURPOSE

The clinical manifestations of sarcoidosis vary widely, depending on the intensity of the inflammation and the organ systems affected. Hence, sarcoidosis patients may suffer from a great variety of symptoms. The aim of this study was to compare the self-reported burden of sarcoidosis patients in Denmark, Germany and the Netherlands, especially the prevalence of fatigue and small fiber neuropathy (SFN)-related symptoms, as well as differences in treatment strategies.

METHODS

A cross-sectional web-based anonymous survey about complaints was conducted among sarcoidosis patients. Patients were invited to take part through the sarcoidosis patient societies as well as through outpatient sarcoidosis clinics in these countries.

RESULTS

The questionnaire was completed by 1072 sarcoidosis patients (152 Danish, 532 German and 388 Dutch). Almost all patients reported having sarcoidosis-associated symptoms (organ-related as well as non-specific, non-organ related). Fatigue was reported by almost all respondents (90%), followed by pulmonary symptoms (72.4%). More than 50% of the respondents were being treated with prednisone, which was comparable in all three countries. In contrast, second- and third-line treatment differed substantially between Denmark, Germany and the Netherlands.

CONCLUSION

Sarcoidosis patients in Denmark, Germany and the Netherlands present with similar self-reported symptoms, organ-related as well as non-specific, non-organ related. Fatigue (90%) and symptoms associated with SFN (86%) were highly prevalent in all three countries.

Structural progression rate decreases over time on serial radiography and magnetic resonance imaging of sacroiliac joints and spine in a five-year follow-up study of patients with ankylosing spondylitis treated with tumour necrosis factor inhibitor

OBJECTIVE

To investigate temporal changes in structural progression assessed by serial conventional radiography and magnetic resonance imaging (MRI) of the sacroiliac joints (SIJs) and spine in patients with ankylosing spondylitis (AS) treated with tumour necrosis factor (TNF) inhibitor for 5 years.

METHOD

Forty-two patients were included and 33 patients were followed for 5 years in a prospective investigator-initiated study. Conventional radiographs were required four times and MRI seven times. The modified Stoke Ankylosing Spondylitis Spinal Score (mSASSS); Spondyloarthritis Research Consortium of Canada (SPARCC) MRI SIJ and Spine Inflammation, and SPARCC MRI SIJ Structural Score (SSS) for Fat, Erosion, Backfill, and Ankylosis; and the Canada-Denmark MRI scores for Spine Inflammation, Fat, Erosion, and New Bone Formation (NBF) were applied.

RESULTS

Compared with baseline, MRI Inflammation had decreased significantly at week 22 (spine)/week 46 (SIJ) and thereafter. MRI SIJ Fat (from week 22), SIJ Ankylosis, Spine NBF, and mSASSS had increased significantly at week 46 and thereafter. SIJ Erosion had decreased from year 2. The annual progression rate in mSASSS was significantly higher during weeks 0-46 compared to week 46 to year 3. In multivariate regression analyses, baseline SIJ Inflammation and Backfill were independent predictors of 5 year progression in SIJ Ankylosis. Spine Erosion predicted progression in Spine NBF. Longitudinally, Ankylosing Spondylitis Disease Activity Score, Bath Ankylosing Spondylitis Disease Activity Index, MRI Spine Inflammation, Fat, and Erosion scores were significantly associated with mSASSS. SIJ Inflammation, Fat, Erosion, and Backfill scores were longitudinally associated with SIJ Ankylosis. Structural progression was not associated with body mass index, smoking, or Assessment of SpondyloArthritis international Society Non-Steroidal Anti-Inflammatory Drug Index.

CONCLUSION

In a 5 year follow-up study of patients with AS treated with TNF inhibitor, structural progression decreased over time.

[Sarcoidosis]

Sarcoidosis is a multisystem granulomatous disease of unknown cause, histologically characterised by non-caseating granulomas. Sarcoidosis most commonly affects the lungs, but all organs can be involved, and there is a variable natural course from an asymptomatic state to a progressive disease. Sarcoidosis is a diagnosis of exclusion, and CT scan, endobronchial ultrasound-guided trans-bronchial needle aspiration and fluorodeoxyglucose positron emission tomography facilitate the diagnostic workup. Patients with severe symptoms or threatening organ damage require systemic treatment.

[Idiopathic pulmonary fibrosis is an overlooked disease]

Idiopathic pulmonary fibrosis is a chronic, progressive and fatal disease which primarily occurs in male patients over 60 years with a smoking history. Cryobiopsy is a new promising method for obtaining lung tissue for histologic analysis with fewer complications than surgical lung biopsy. Cryobiopsy allows more patients to be diagnosed. Antifibrotic treatment has shown to decrease progression and prolong survival time in both early and later stages of the disease. Early diagnosis and treatment are therefore of great importance to prevent disease progression and reduce mortality.

Hypersensitivity pneumonitis among wind musicians - an overlooked disease?

Hypersensitivity pneumonitis (HP) is a complex pulmonary disorder mediated by the immune system and caused by various inhaled antigens against which the subject has previously been sensitized. In about 50% of the cases, the antigen is not identified. Identification and removal of the eliciting antigen is important for the prognosis.

We report two cases of HP caused by molds and atypical mycobacteria isolated from wind instruments. We present the first case of HP caused by bassoon playing and another case of HP caused by molds in a trombone. HP caused by fungi and bacteria in wind instruments may be much more common than previously thought.

HP caused by fungi and bacteria in wind instruments is probably underdiagnosed; this calls for more clinical attention when HP is suspected.

Investigation of a multi-biomarker disease activity score in rheumatoid arthritis by comparison with magnetic resonance imaging, computed tomography, ultrasonography, and radiography parameters of inflammation and damage

OBJECTIVES

To investigate the multi-biomarker disease activity (MBDA) score by comparison with imaging findings in an investigator-initiated rheumatoid arthritis (RA) trial (HURRAH trial, NCT00696059).

METHOD

Fifty-two patients with established RA initiated adalimumab treatment and had magnetic resonance imaging (MRI), ultrasonography (US), computed tomography (CT), and radiography performed at weeks 0, 26, and 52. Serum samples were analysed using MBDA score assays and associations between clinical measures, MBDA score, and imaging findings were investigated.

RESULTS

The MBDA score correlated significantly with MRI synovitis (rho = 0.65, p < 0.001), MRI bone marrow oedema (rho = 0.36, p = 0.044), and US power Doppler (PD) score at week 26 (rho = 0.35, p = 0.039) but not at week 0 or week 52. In the 15 patients who had achieved a Disease Activity Score based on C-reactive protein (DAS28-CRP) < 2.6 at week 26, MRI and/or US detected subclinical inflammation and 13 (87%) had a moderate/high MBDA score. For the cohort with available data, none of the four patients in MBDA remission (score ≤ 25) at week 26 had progression of imaging damage from baseline to week 52 whereas progression was observed in three out of nine (33%) and seven out of 21 (33%) patients with moderate (30-44) and high (> 44) MBDA scores, respectively.

CONCLUSIONS

In this cohort, the MBDA score correlated poorly with MRI/US inflammation. However, the MBDA score and MRI/US were generally concordant in showing signs of inflammation in most patients in clinical remission during anti-tumour necrosis factor (anti-TNF) therapy. MBDA scores were elevated in all patients with structural damage progression.

Markov properties of cluster processes

We show that a Poisson cluster point process is a nearest-neighbour Markov point process [2] if the clusters have uniformly bounded diameter. It is typically not a finite-range Markov point process in the sense of Ripley and Kelly [12]. Furthermore, when the parent Poisson process is replaced by a Markov or nearest-neighbour Markov point process, the resulting cluster process is also nearest-neighbour Markov, provided all clusters are non-empty. In particular, the nearest-neighbour Markov property is preserved when points of the process are independently randomly translated, but not when they are randomly thinned.

Random tessellations in ℝd

This paper presents a general theory of random tessellations (i.e. stochastic aggregates of disjoint and space-filling cells) ind-dimensional Euclidean space. Some particular models of random tessellations are discussed in detail.

Detection and spatial characterization of minicolumnarity in the human cerebral cortex

BACKGROUND

Spatial characterization of vertical organization of neurons in human cerebral cortex, cortical columnarity or minicolumns, and its possible association with various psychiatric and neurological diseases has been investigated for many years.

NEW METHOD

In this study, we obtained 3D coordinates of disector sampled cells from layer III of Brodmann area 4 of the human cerebral cortex using light microscopy and 140-μm-thick glycolmethacrylate sections. A new analytical tool called cylindrical K-function was applied for spatial point pattern analysis of 3D datasets to see whether there is a spatially organized columnar structure. In order to demonstrate the behaviour of the cylindrical K-function, the result from brain tissues was compared with two models: A homogeneous Poisson process exhibiting complete spatial randomness, and a Poisson line cluster point process. The latter is a point process model in 3D space, which exhibits spatial structure of points similar to minicolumns.

RESULTS

The data show in three out of four samples nonrandom patterns in the 3D neuronal positions with the direction of minicolumns perpendicular to the pial surface of the brain - without a priori assuming the existence of minicolumns.

COMPARISON WITH EXISTING METHODS

Studies on columnarity are difficult and have mainly been based on two-dimensional images analysis of thin sections of the cerebral cortex with the a priori assumption that minicolumns existed.

CONCLUSIONS

A clear difference from complete spatial randomness in the data could be detected with the new tool, the cylindrical K-function, although classical functional summary statistics are less useful in this connection.

Airway foreign body aspiration: common, yet easily overlooked! Two interesting cases

Two cases: A 66-year-old woman was referred to the hospital due to dyspnoea and cough. Seven months prior to referral, the patient had choked on a chunk of nut and grain-filled bread. She had daily cough and dyspnoea. The patient was convinced of an airway foreign body and she contacted her general practitioner and the emergency service several times; they all found this unlikely. Fibre optic bronchoscopy revealed two obstructing nut-like foreign bodies in the right upper and lower lobe, respectively. A 77-year-old man with sarcoidosis developed increased dyspnoea and sputum production. Three weeks earlier, the patient had choked on a magnesium tablet. Everyone was convinced that the tablet had dissolved. Infection was suspected. Chest CT scan was performed showing no obvious signs of infection or progression in sarcoidosis. After the CT scan, the patient coughed up the remains of the tablet and his symptoms resolved. Retrospective evaluation of the CT scan revealed the tablet.

Waste collection systems for recyclables: an environmental and economic assessment for the municipality of Aarhus (Denmark)

Recycling of paper and glass from household waste is an integrated part of waste management in Denmark, however, increased recycling is a legislative target. The questions are: how much more can the recycling rate be increased through improvements of collection schemes when organisational and technical limitations are respected, and what will the environmental and economic consequences be? This was investigated in a case study of a municipal waste management system. Five scenarios with alternative collection systems for recyclables (paper, glass, metal and plastic packaging) were assessed by means of a life cycle assessment and an assessment of the municipality's costs. Kerbside collection would provide the highest recycling rate, 31% compared to 25% in the baseline scenario, but bring schemes with drop-off containers would also be a reasonable solution. Collection of recyclables at recycling centres was not recommendable because the recycling rate would decrease to 20%. In general, the results showed that enhancing recycling and avoiding incineration was recommendable because the environmental performance was improved in several impact categories. The municipal costs for collection and treatment of waste were reduced with increasing recycling, mainly because the high cost for incineration was avoided. However, solutions for mitigation of air pollution caused by increased collection and transport should be sought.

The commutability of external quality assurance serum and reference serum materials between the VITROS® Albumin Slide and four other routine albumin methods

Background

Between-method differences in external quality assurance schemes (EQAS) are assumed to be indicative of between-method differences in results for fresh diagnostic serum samples. However, this assumption is only valid if the EQAS fluid is shown to be commutable between methods with the fresh human samples. Using fresh human serum samples, we studied the commutability of six UK National EQAS (UKNEQAS) samples and two reference serum preparations using five methods for the measurement of albumin.

Methods

The VITROS® Albumin Slide was compared with two liquid reagent bromocresol green-based methods and two immunoturbidimetric methods. Thirty fresh human serum samples, six UKNEQAS samples and two reference materials were analysed over a period of five days by all methods. The reference materials were: a certified protein reference material, CRM470 (protein reference preparation) and the Scandinavian NFKK Reference Serum X.

Results

A concentration-dependent tendency towards non-commutability was seen for the six UKNEQAS samples. Two of the methods recovered the CRM470 above the upper limit of the expected range and the remaining three were within the expected range.

Conclusions

Assessment of commutability is important in the investigation of between-method differences in EQAS. External quality assurance and reference materials should have been demonstrated to be commutable and be available at multiple concentrations, before they may be considered appropriate for the assessment of accuracy.

Microbiological assessments of compost toilets: in situ measurements and laboratory studies on the survival of fecal microbial indicators using sentinel chambers

Compost toilet systems were assessed for their ability to reduce microbial indicators and pathogens. Bacterial pathogens were not detected in any samples indicating a low survival rate in composting feces and/or an initial low occurrence. Indicator bacteria showed large variations with no clear trend of lower bacterial numbers after longer storage. In controlled composting experiments, thermophilic conditions were only reached when amendments were made (grass and a sugar solution). Even then it was impossible to ensure a homogenous temperature in the composting fecal material and therefore difficult to achieve a uniform reduction and killing of indicator organisms. Presumptive thermotolerant coliforms, Salmonella typhimurium Phage 28 B and eggs of Ascaridia galli, proved useful as indicators. However, regrowth was detected for enterococci and total numbers of bacteria grown at 36 degrees C. These indicator parameters may therefore overestimate the level of other (pathogenic) bacteria present in the material and can not be recommended for use as reliable indicator organisms in composting toilet systems. The addition of indicator bacteria to fecal material contained in semi-permeable capsules proved to be a useful technique to ensure that microorganisms were contained in a small test volume.

Detection of MTRR 66A-->G polymorphism using the real-time polymerase chain reaction machine LightCycler for determination of composition of allele after restriction cleavage

The MTRR gene codes for methionine synthase reductase, one of the enzymes involved in the conversion of homocysteine to methionine. This conversion influences the overall level of total plasma homocysteine (tHcy) and mutations, which reduces the enzyme activity and results in an increased concentration of tHcy. A high homocysteine level is a well-documented independent risk factor for cardiovascular disease. A polymorphism in the gene for methionine synthase reductase (MTRR 66 A>G) has been shown to be associated with the risk of giving birth to a child with Down's syndrome, and the risk of having a foetus with neural tube defects. We have established a method for analysing MTRR 66A>G on DNA from dried blood spots using melting temperature analysis. The DNA was extracted from dried blood spots using a fast procedure by boiling only.

A longitudinal study of serum cobalamins and its binding proteins in lactating women

OBJECTIVE

To examine longitudinal changes in serum cobalamins, transcobalamin (TC) and haptocorrin (HC) during lactation and to investigate the influence of vitamin B12 supplementation on these parameters.

DESIGN

A 9-month follow-up study.

SUBJECTS AND METHODS

Lactating mothers (N=89) including 23 supplemented with vitamin B12 (1-18 microg/daily), 41 partly supplemented and 25 not supplemented. Blood samples collected 3 weeks (baseline) and 4 and 9 months post-partum were analysed for cobalamins, TC and HC. Both the total concentration and the cobalamin-saturated form (holo) of TC and HC were analysed.

RESULTS

No significant differences were observed in serum cobalamins or its binding proteins related to supplementation with vitamin B12 or the duration of lactation. Serum cobalamins remained unchanged from 3 weeks to 9 months post-partum. Total TC (holoTC) (median+/-s.e. pmol/l) decreased between 3 weeks (710+/-23 (85+/-12)) and 9 months (602+/-21 (76+/-11)) (P<0.0001 (P=0.0002)), whereas total HC (holoHC) increased from (422+/-11 (300+/-9)) at 4 months to (455+/-13 (317+/-10)) to 9 months post-partum (P<0.0001 (P<0.0001)).

CONCLUSION

We report a decrease in TC and an increase in HC during a 9-month period post-partum. No differences were observed between the vitamin B12-supplemented and the unsupplemented groups. Thus, supplementation with vitamin B12 has no impact on the circulating level of serum cobalamins or its binding proteins in a Danish population of lactating mothers.

Folate and vitamin B12 in relation to lactation: a 9-month postpartum follow-up study

OBJECTIVE

To investigate the relation between lactation and markers of folate and vitamin B12 (B12) deficiency in women with and without vitamin supplementation.

DESIGN

A 9-month follow-up study.

SUBJECTS AND METHODS

Blood samples from 91 women, who gave birth to a single healthy child, were collected 3 weeks, 4 and 9 months postpartum and analysed for circulating level of homocysteine (tHcy), methylmalonic acid (MMA), folate and B12. The participants were categorized as exclusively, partly or not breast-feeding dependent on the degree of lactation 4 months postpartum. During follow-up, lifestyle factors were recorded by structured interviews.

RESULTS

Among 72 exclusively breast-feeding women, the median (10-90% percentile) tHcy was 5.8 (3.1-8.3) micromol/l 3 weeks postpartum, 6.1 (4.1-10.3) micromol/l 4 months postpartum and 5.3 (3.6-8.7) micromol/I 9 months postpartum. At 9 months postpartum, none of the women breast-fed exclusively. No significant change occurred in the concentration of B12 and folate. Exclusively breast-feeding women without vitamin supplementation had higher median tHcy than supplemented exclusively breast-feeding women 4 and 9 months postpartum (7.0 vs 5.4 micromol/l (P < 0.001) and 5.8 vs 4.5 micromol/l (P = 0.003), respectively). Six women had increased (>15 micromol/l) tHcy; four of these were unsupplemented and exclusively breast-feeding.

CONCLUSION

We found no overall indication of depletion of the folate and B12 stores during the lactation period in this population. However, folate-supplemented women had lower tHcy and higher folate levels, suggesting a beneficial effect of supplementation with folate throughout lactation.

Exercise, hormones, and body temperature. regulation and action of GH during exercise

That physical exercise stimulates pituitary GH secretion has been known for forty years, but the underlying mechanisms as well as the physiological significance remain elusive. We have previously shown that the concomitant increase in core temperature is essential for the exercise-induced GH release, inasmuch as exercise performed at 4 C results in a suppression of GH secretion, whereas passive heating constitutes a potent stimulus for GH release. Moreover, studies in normal subjects show that GH stimulates sweat production and evaporative heat loss during heat exposure with and without exercise, whereas GH-deficiency is associated with reduced sweat secretion and increased heat storage during similar conditions. The neurotransmitters involved in GH secretion during exercise remain uncertain; we therefore investigated the putative role of ghrelin, which is a gut-derived endogenous ligand for the GHS receptor. We measured circulating ghrelin levels before during and after submaximal aerobic exercise in healthy subjects and GH-deficient patients. The circulating ghrelin levels were unchanged during and after exercise in all subjects. Growth hormone stimulates lipolysis and lipid oxidation during basal and fasting conditions and we recently investigated whether GH also regulates substrate metabolism during exercise. The design involved GH-deficient patients studied during exercise with and without GH administration as compared to untreated healthy subjects. Growth hormone predominantly stimulated the turnover of free fatty acids in the recovery phase after exercise.

CONCLUSIONS

1) the increase in GH release during exercise is associated with the concomitant increase in body temperature, 2) GH stimulates sweat secretion and heat evaporation during exercise, which seems to be of distinct physiological significance, 3) ghrelin is not involved in exercise-induced GH release, 4) the impact of GH on substrate metabolism during exercise includes increased FFA turnover.

Evaluation of the DPC IMMULITE 2000 assay for total homocysteine in plasma

The present report describes an evaluation in three laboratories of the completely automated total homocysteine immunoassay adapted to the IMMULITE 2000 from DPC. The precision depended on the control materials used, but with quality control materials and patient samples imprecisions were found to be in the range of 5.3 to 6.1% and 5.4 to 6.0%, respectively. Dilution experiments proved the assay to be linear and correlations with HPLC and GC-MS methods were close (r=0.98 and 0.97, respectively). In addition, the samples from the Nordic program for external quality assessment of methylmalonic acid and homocysteine for 2000 were assayed in the three laboratories. Imprecision evaluated from these samples was 5.3% and the recovery of the added L-homocystine was equivalent to the mean recovery of the 58 participants in the program. The precision is close to the quality goals. In conclusion, the method is an attractive alternative when coping with an increasing number of requests for the analysis of total homocysteine.

Remifentanil vs. alfentanil for direct laryngoscopy: a randomized study comparing two total intravenous anaesthesia techniques. TIVA for direct laryngoscopy

The ideal anaesthesia for direct laryngoscopy is profound and yet brief. The present study sought to determine whether a new anaesthetic technique based on infusion of the ultra short-acting opioid remifentanil was superior to our routine alfentanil multiple-dose technique in terms of haemodynamic stability, stress responses and recovery. A total of 58 patients were randomized to receive propofol and either remifentanil or alfentanil as part of a total intravenous anaesthesia. In the remifentanil group, systolic blood pressure during anaesthesia remained significantly lower than baseline values, while it increased significantly in the alfentanil group. None of the patients receiving remifentanil showed stress responses (hypertension, tachycardia, somatic or autonomic responses), compared to 22 patients (79%) in the alfentanil group (P < 0.0001). In the remifentanil group, hypotension or bradycardia requiring intervention arose in 5 (18%) and 3 patients (11%); neither response was seen in the alfentanil group. The period from the end of propofol infusion until extubation was 5 min longer in the remifentanil group (P < 0.0001), whereas the time from extubation until discharge was similar in the two groups. Thus, neither technique showed sufficient haemodynamic stability, and further studies are needed to determine optimal dosages of propofol and opioid.

Platelet activity and in vivo arterial thrombus formation in rats with mild hyperhomocysteinaemia

Elevated plasma levels of total homocysteine (hcy) have been associated with an increased occurrence of arterial thrombosis. In the present study, we investigated the influence of hyperhomocysteinaemia on platelet aggregation and arterial thrombus formation in vivo. Fifty-one rats were included in the study, of which 29 received hcy in the drinking water for 4 weeks. Blood samples were withdrawn for measurement of platelet count and mean platelet volume. Platelet aggregation response in platelet-rich plasma following adenosine diphosphate or collagen stimulation were examined. In vivo thrombus formation was investigated by transillumination and videotape recording of the rat femoral artery after a thrombogenic injury was established. Off-line videotape analysis using computer-assisted planimetry permitted quantification of the thrombus area, and area versus time curves were obtained. In the intervention group receiving hcy, total hcy in plasma increased two-fold to 14.3 micromol/l, as compared with 7.3 micromol/l in the control group (P < 0.001). The platelet count and mean platelet volume did not differ between the two groups. In vivo thrombus formation expressed as the area under the curve or maximum thrombus area was not found to be altered in the presence of an increased homocysteine level, neither was adenosine diphosphate-induced platelet aggregation. However, collagen-induced platelet aggregation significantly decreased in the hcy group (P = 0.02). Pro-thrombotic effects of isolated mild hyperhomocysteinaemia are not supported by the present study in rats.

Homocysteine and atherothrombosis

Atherosclerosis with or without thrombosis superimposed is the most frequent cause of ischemic heart disease (IHD), peripheral arterial disease, and a main cause of stroke. Conflicting results have been reported in genetic, observational, and experimental studies on the relationship between homocysteine and these atherothrombotic diseases. Although cardiovascular complications are common in homocystinuric patients (severe hyperhomocysteinemia), IHD, the most frequent manifestation of atherothrombosis in the general population, appears to be rare. On the basis of findings in individuals with hyperhomocysteinemia of genetic origin, there is in fact no clear evidence for a causal role of homocysteine in the pathogenesis of atherothrombotic disease, and the positive association between plasma homocysteine and IHD observed in many, but not all epidemiologic studies does not prove causality. To infer causality from observational studies, there should be a temporal, consistent, strong, independent, graded (dose-response effect), and duration-dependent relationship between exposure and outcomes, and a biologically plausible mechanism should exist. The relationship between plasma homocysteine levels and IHD does not fulfill these criteria beyond reasonable doubt. In the general population, plasma homocysteine levels are to a great extent determined by dietary habits, and plasma homocysteine could be a marker, or a consequence, of atherothrombosis and/or risk-associated behavior (e.g., a diet low in fruits and vegetables) rather than a cause of atherothrombosis. Experimentally, hyperhomocysteinemia is not in itself atherogenic in normal animals with relatively low plasma cholesterol levels. The homocysteine theory of atherosclerosis should be tested more thoroughly in hypercholesterolemic animals that develop atherosclerosis spontaneously to determine whether elevated plasma homocysteine levels are harmful under atherogenic conditions. A causal role of homocysteine in atherothrombotic disease remains to be established.