Presymptomatic cognitive and neuroanatomical changes in genetic frontotemporal dementia in the Genetic Frontotemporal dementia Initiative (GENFI) study: a cross-sectional analysis

BACKGROUND

Frontotemporal dementia is a highly heritable neurodegenerative disorder. In about a third of patients, the disease is caused by autosomal dominant genetic mutations usually in one of three genes: progranulin (GRN), microtubule-associated protein tau (MAPT), or chromosome 9 open reading frame 72 (C9orf72). Findings from studies of other genetic dementias have shown neuroimaging and cognitive changes before symptoms onset, and we aimed to identify whether such changes could be shown in frontotemporal dementia.

METHODS

We recruited participants to this multicentre study who either were known carriers of a pathogenic mutation in GRN, MAPT, or C9orf72, or were at risk of carrying a mutation because a first-degree relative was a known symptomatic carrier. We calculated time to expected onset as the difference between age at assessment and mean age at onset within the family. Participants underwent a standardised clinical assessment and neuropsychological battery. We did MRI and generated cortical and subcortical volumes using a parcellation of the volumetric T1-weighted scan. We used linear mixed-effects models to examine whether the association of neuropsychology and imaging measures with time to expected onset of symptoms differed between mutation carriers and non-carriers.

FINDINGS

Between Jan 30, 2012, and Sept 15, 2013, we recruited participants from 11 research sites in the UK, Italy, the Netherlands, Sweden, and Canada. We analysed data from 220 participants: 118 mutation carriers (40 symptomatic and 78 asymptomatic) and 102 non-carriers. For neuropsychology measures, we noted the earliest significant differences between mutation carriers and non-carriers 5 years before expected onset, when differences were significant for all measures except for tests of immediate recall and verbal fluency. We noted the largest Z score differences between carriers and non-carriers 5 years before expected onset in tests of naming (Boston Naming Test -0·7; SE 0·3) and executive function (Trail Making Test Part B, Digit Span backwards, and Digit Symbol Task, all -0·5, SE 0·2). For imaging measures, we noted differences earliest for the insula (at 10 years before expected symptom onset, mean volume as a percentage of total intracranial volume was 0·80% in mutation carriers and 0·84% in non-carriers; difference -0·04, SE 0·02) followed by the temporal lobe (at 10 years before expected symptom onset, mean volume as a percentage of total intracranial volume 8·1% in mutation carriers and 8·3% in non-carriers; difference -0·2, SE 0·1).

INTERPRETATION

Structural imaging and cognitive changes can be identified 5-10 years before expected onset of symptoms in asymptomatic adults at risk of genetic frontotemporal dementia. These findings could help to define biomarkers that can stage presymptomatic disease and track disease progression, which will be important for future therapeutic trials.

FUNDING

Centres of Excellence in Neurodegeneration.

In vitro studies on periodontal ligament cells and enamel matrix derivative

The recognition that periodontal regeneration can be achieved has resulted in increased efforts focused on understanding the mechanisms and factors required for restoring periodontal tissues so that clinical outcomes of such therapies are more predictable than those currently being used. In vitro models provide an excellent procedure for providing clues as to the mechanisms that may be required for regeneration of tissues. The investigations here were targeted at determining the ability of enamel matrix derivative (EMD) to influence specific properties of periodontal ligament cells in vitro. Properties of cells examined included migration, attachment, proliferation, biosynthetic activity and mineral nodule formation. Immunoassays were done to determine whether or not EMD retained known polypeptide factors. Results demonstrated that EMD under in vitro conditions formed protein aggregates, thereby providing a unique environment for cell-matrix interaction. Under these conditions, EMD: (a) enhanced proliferation of PDL cells, but not of epithelial cells; (b) increased total protein production by PDL cells; (c) promoted mineral nodule formation of PDL cells, as assayed by von Kossa staining; (d) had no significant effect on migration or attachment and spreading of cells within the limits of the assay systems used here. Next, EMD was screened for possible presence of specific molecules including: GM-CSF, calbindin D, EGF, fibronectin, bFGF, gamma-interferon, IL-1 beta, 2, 3, 6; IGF-1,2; NGF, PDGF, TNF, TGF beta. With immunoassays used, none of these molecules were identified in EMD. These in vitro studies support the concept that EMD can act as a positive matrix for cells at a regenerative site.

Adults with cerebral palsy: a survey describing problems, needs, and resources, with special emphasis on locomotion

The purpose of this study was to describe problems and resources of adults with cerebral palsy (CP) with special emphasis on locomotion. A questionnaire concerning demographic facts, locomotion, musculoskeletal problems, and present physical activity was mailed to 363 adults with CP. Two hundred and twenty-one adults, (125 male and 96 female; mean age 36 years, range 20 to 58 years) answered the questionnaire. Seventy-seven per cent reported problems with spasticity. Eighty-four per cent lived in their own apartments, with or without home services. Twenty-four per cent worked full-time and 18% had full disability pension. Twenty-seven per cent had never been able to walk, 64% could walk with or without walking aids, 35% reported decreased walking ability, and 9% had stopped walking. Eighty per cent reported contractures and 18% had pain every day. Approximately 60% were regularly physically active, and despite their disability, 54% considered that they were not limited in their ability to move about in the community.

Autocrine growth factors in human periodontal ligament cells cultured on enamel matrix derivative

OBJECTIVE

Enamel extracellular matrix proteins in the form of the enamel matrix derivative EMDOGAIN (EMD) have been successfully employed to mimic natural cementogenesis to restore fully functional periodontal ligament, cementum and alveolar bone in patients with severe periodontitis. When applied to denuded root surfaces EMD forms a matrix that locally facilitates regenerative responses in the adjacent periodontal tissues. The cellular mechanism(s), e.g. autocrine growth factors, extracellular matrix synthesis and cell growth, underlying PDL regeneration with EMD is however poorly investigated.

MATERIAL AND METHODS

Human periodontal ligament (PDL) cells were cultured on EMD and monitored for cellular attachment rate, proliferation, DNA replication and metabolism. Furthermore, intracellular cyclic-AMP levels and autocrine production of selected growth factors were monitored by immunological assays. Controls included PDL and epithelial cells in parallel cultures.

RESULTS

PDL cell attachment rate, growth and metabolism were all significantly increased when EMD was present in cultures. Also, cells exposed to EMD showed increased intracellular cAMP signalling and autocrine production of TGF-beta1, IL-6 and PDGF AB when compared to controls. Epithelial cells increased cAMP and PDGF AB secretion when EMD was present, but proliferation and growth were inhibited.

CONCLUSION

Cultured PDL cells exposed to EMD increase attachment rate, growth rate and metabolism, and subsequently release several growth factors into the medium. The cellular interaction with EMD generates an intracellular cAMP signal, after which cells secrete TGF-beta1, IL-6 and PDGF AB. Epithelial cell growth however, is inhibited by the same signal. This suggest that EMD favours mesenchymal cell growth over epithelium, and that autocrine growth factors released by PDL cells exposed to EMD contribute to periodontal healing and regeneration in a process mimicking natural root development.

Formulation of enamel matrix derivative for surface coating. Kinetics and cell colonization

Enamel Matrix Derivative (EMD) contains a protein complex belonging to the amelogenin family. Enamel matrix as well as EMD have been found to promote periodontal regeneration when applied onto denuded root surfaces in dehiscence models. In the present studies it is shown that propylene glycol alginate (PGA) is a suitable vehicle for EMD for its local application. EMD can be dissolved in PGA at an acidic pH, resulting in a highly viscous solution. At neutral pH and body temperature the viscosity decreases and EMD precipitates. Multilayers of EMD on mineral or protein surfaces have been analysed using ellipsometry, total internal reflection fluorescence (TIRF) and biospecific interaction analysis (BIA). The studies show that EMD adsorbs both to hydroxyapatite and collagen and to denuded dental roots. It forms insoluble spherical complexes, and detectable amounts remain at the site of application on the root surface for two weeks, as shown with radiolabelled protein in rats and pigs. Scanning electron micrograph (SEM) studies on monkey teeth further indicate that EMD in PGA may promote repopulation of fibroblast-like cells during the first weeks after application.

Bleeding risk in 'real world' patients with atrial fibrillation: comparison of two established bleeding prediction schemes in a nationwide cohort

BACKGROUND

Oral anticoagulation (OAC) in patients with atrial fibrillation (AF) is a double-edged sword, because it decreases the risk of stroke at the cost of an increased risk of bleeding. We compared the performance of a new bleeding prediction scheme, HAS-BLED, with an older bleeding prediction scheme, HEMORR(2)HAGES, in a cohort of 'real-world' AF patients.

METHODS

By individual-level-linkage of nationwide registers, we identified all patients (n = 118,584) discharged with non-valvular AF in Denmark during the period 1997-2006, with and without OAC. Major bleeding rates during 1 year of follow-up were determined, and the predictive capabilities of the two schemes were compared by c-statistics. The risk of bleeding associated with individual risk factors composing HAS-BLED was estimated using Cox proportional-hazard analyses.

RESULTS

Of AF patients receiving OAC (n = 44,771), 34.8% and 47.3% were categorized as 'low bleeding risk' by HAS-BLED and HEMORR(2)HAGES, respectively, and the bleeding rates per 100 person-years were 2.66 (95% confidence interval [CI], 2.40-2.94) and 3.06 (2.83-3.32), respectively. C-statistics for the two schemes were 0.795 (0.759-0.829) and 0.771 (0.733-0.806), respectively. The risk factors composing HAS-BLED were associated with varying risks, with a history of bleeding (hazard ratio [HR] 2.98; 95% CI 2.68-3.31) and being elderly (HR 1.93; 95% CI 1.71-2.18) being associated with the highest risks. Comparable results were found in AF patients not receiving OAC (n = 77,813).

CONCLUSIONS

In an unselected nationwide cohort of hospitalized patients with atrial fibrillation, the HAS-BLED score performs similarly to HEMORR(2)HAGES in predicting bleeding risk but HAS-BLED is much simpler and easier to use in everyday clinical practise.

Obesity increases the risk of incident asthma among adults

The annual incidence of asthma in adults in northern Sweden has been estimated at 2.3 per thousand population. Risk factors for incident asthma among adults were studied in a case-referent study based on incident cases of asthma during 1995-1999. The healthcare providers reported suspected cases of incident asthma. After clinical examination, 309 (65% female) of 473 reported subjects were included. Inclusion criteria were a history of incident asthma (onset <12 months) and verified bronchial variability. Referents were randomly selected and stratified by age, sex and area of residence. The significant risk factors were hay fever, a family history of asthma, ex-smoking status and elevated body mass index (25.0-29.9 and > or =30). The risk factor pattern was similar for females and males, and increased body mass index was a significant risk factor for both males and females, as well as for allergic and nonallergic subjects. In conclusion, in addition to hay fever, a family history of asthma, allergic sensitisation and ex-smoking status, increased body mass index was a significant risk factor for incident asthma independent of sex and allergic status.

Rotational and translational movement features of the pelvis and thorax during adult human locomotion

The kinematics of the pelvis and thorax are important in gait studies since their movement patterns are closely related to gait efficiency and 'smoothness' of locomotion. The purpose of this study was to identify features of normal gait patterns for later comparisons with pathological and developmental gait patterns. A two camera SELSPOT system interfaced with an HP1000 minicomputer was used to obtain three-dimensional kinematic/temporal data for the pelvis and thorax. Data from treadmill walking of eight adults were used for within subject (at different speeds) analyses. The analyses revealed a very complex pattern with a set of breakpoints which was consistent over all subjects. Some features were invariant over a range of walking speeds although the total range of motion changed considerably.

Serum neurofilament light chain in genetic frontotemporal dementia: a longitudinal, multicentre cohort study

BACKGROUND

Neurofilament light chain (NfL) is a promising blood biomarker in genetic frontotemporal dementia, with elevated concentrations in symptomatic carriers of mutations in GRN, C9orf72, and MAPT. A better understanding of NfL dynamics is essential for upcoming therapeutic trials. We aimed to study longitudinal NfL trajectories in people with presymptomatic and symptomatic genetic frontotemporal dementia.

METHODS

We recruited participants from 14 centres collaborating in the Genetic Frontotemporal Dementia Initiative (GENFI), which is a multicentre cohort study of families with genetic frontotemporal dementia done across Europe and Canada. Eligible participants (aged ≥18 years) either had frontotemporal dementia due to a pathogenic mutation in GRN, C9orf72, or MAPT (symptomatic mutation carriers) or were healthy at-risk first-degree relatives (either presymptomatic mutation carriers or non-carriers), and had at least two serum samples with a time interval of 6 months or more. Participants were excluded if they had neurological comorbidities that were likely to affect NfL, including cerebrovascular events. We measured NfL longitudinally in serum samples collected between June 8, 2012, and Dec 8, 2017, through follow-up visits annually or every 2 years, which also included MRI and neuropsychological assessments. Using mixed-effects models, we analysed NfL changes over time and correlated them with longitudinal imaging and clinical parameters, controlling for age, sex, and study site. The primary outcome was the course of NfL over time in the various stages of genetic frontotemporal dementia.

FINDINGS

We included 59 symptomatic carriers and 149 presymptomatic carriers of a mutation in GRN, C9orf72, or MAPT, and 127 non-carriers. Nine presymptomatic carriers became symptomatic during follow-up (so-called converters). Baseline NfL was elevated in symptomatic carriers (median 52 pg/mL [IQR 24-69]) compared with presymptomatic carriers (9 pg/mL [6-13]; p<0·0001) and non-carriers (8 pg/mL [6-11]; p<0·0001), and was higher in converters than in non-converting carriers (19 pg/mL [17-28] vs 8 pg/mL [6-11]; p=0·0007; adjusted for age). During follow-up, NfL increased in converters (b=0·097 [SE 0·018]; p<0·0001). In symptomatic mutation carriers overall, NfL did not change during follow-up (b=0·017 [SE 0·010]; p=0·101) and remained elevated. Rates of NfL change over time were associated with rate of decline in Mini Mental State Examination (b=-94·7 [SE 33·9]; p=0·003) and atrophy rate in several grey matter regions, but not with change in Frontotemporal Lobar Degeneration-Clinical Dementia Rating scale score (b=-3·46 [SE 46·3]; p=0·941).

INTERPRETATION

Our findings show the value of blood NfL as a disease progression biomarker in genetic frontotemporal dementia and suggest that longitudinal NfL measurements could identify mutation carriers approaching symptom onset and capture rates of brain atrophy. The characterisation of NfL over the course of disease provides valuable information for its use as a treatment effect marker.

FUNDING

ZonMw and the Bluefield project.

Clinical safety of enamel matrix derivative (EMDOGAIN) in the treatment of periodontal defects

The aim of the present clinical trial was to test tolerability during 2 treatments with EMDOGAIN in a large number of patients. An open, controlled study design in 10 Swedish specialist clinics was chosen, with a test group of 107 patients treated with EMDOGAIN in connection with periodontal surgery at 2 surgical test sites per patient. The procedures were performed 2 to 6 weeks apart on one-rooted teeth with at least 4 mm deep intraosseous lesions. A control group of 33 patients underwent flap surgery without EMDOGAIN at 1 comparable site. In total, 214 test and 33 control surgeries were performed. Serum samples were obtained from test patients for analysis of total and specific antibody levels. 10 of the patients had samples taken before and after the first surgery, 56 other samples were taken after one treatment with EMDOGAIN, and 63 after 2 treatments. None of the samples, not even from allergy-prone patients after 2 treatments, indicated deviations from established baseline ranges. This indicates that the immunogenic potential of EMDOGAIN is extremely low when applied in conjunction with periodontal surgery. Comparison between the test and control groups demonstrated the same type and frequency of postsurgical experiences, i.e., reactions caused by the surgical procedure itself. Clinical probing and radiographic evaluation was performed at baseline and 8 months postsurgery. About half of the patients (44 test and 21 control) were also evaluated after 3 years. There was a significant difference between the test and control results at 8 months postsurgery, and this difference had increased further at the 3 year follow-up. The 2.5-3 mm increase in attachment and bone level after treatment with EMDOGAIN was of the same magnitude as seen in the studies with split-mouth design aiming for test of effectiveness of EMDOGAIN.

Geographical distribution of TTR met30 carriers in northern Sweden: discrepancy between carrier frequency and prevalence rate

The first Swedish case of familial amyloidotic polyneuropathy (FAP) was published in 1965. The same transthyretin (TTR met30) mutation as that seen in Japanese, Portuguese, and other populations was also found in Swedish FAP patients. More than 350 patients with clinical manifestations of FAP have been diagnosed in northern Sweden, most of them originating from the areas around Skellefteå and Piteå. The mean age of onset is 56 years, much later than in patients from Japan and Portugal. To estimate the frequency of the TTR met30 mutation in the counties of Västerbotten and Norrbotten, sera from 1276 persons aged 24 to 65 years, randomly sampled from a health programme (MONICA), were screened with the monoclonal antibody FD6. In 19 persons, 13 females and six males, a positive reaction was seen in an Elisa test using this antibody. DNA analysis confirmed the TTR met30 mutation and showed that 18 were heterozygous and one homozygous for this mutation. Other mutations were not looked for in this study. The mean TTR met30 carrier frequency in the area was 1.5% ranging from 0.0 to 8.3% in 23 subpopulations. There was a notable discrepancy between the regional distribution of the TTR met30 allele and the morbidity rate for FAP. The estimated number of TTR met30 gene carriers in a total population of 500,000 in the area is approximately 7500. The penetrance of the TTR met30 mutation shows considerable variation between families, and the overall diagnostic (predictive) value in this population is as low as around 2%.

Characterization of somatomedins from human fetal brain: identification of a variant form of insulin-like growth factor I

A fetal form of somatomedin (insulin-like growth factor) that crossreacts in the fetal brain radioreceptor assay has been proposed to exist in humans. Using this assay to monitor activity during purification, we have isolated a variant form of insulin-like growth factor I (IGF-I) from human fetal brain tissue. The variant IGF-I showed potent crossreaction in the fetal brain radioreceptor assay and stimulated DNA synthesis in fetal brain cells in vitro. Structural analysis revealed the variant IGF-I to have a truncated NH2-terminal region compared to IGF-I isolated from serum. An additional peptide, which displayed less potent crossreaction in the fetal brain radioreceptor assay, was also isolated from the human fetal brain. Partial amino acid sequence analysis revealed identity to insulin-like growth factor II.

Guidance for the safety assessment of botanicals and botanical preparations for use in food and food supplements

There is a growing interest by both consumers and industry for the development of food products with 'functional' properties, or health benefits. These products may take the form of dietary supplements or of foods. The health benefits are given by particular ingredients, and in many cases these are derived from botanicals. The variety of plants providing these functions is large, ranging from staple food sources such as cereals, fruits and vegetables, to herbals as used in traditional medicine. The food or ingredient conferring health properties may consist of the plants themselves, extracts thereof, or more purified components. The scientific literature is abundant with articles not only on the beneficial properties, but also on possible adverse health effects of plants and their components. The present report discusses the data required to determine the safe use of these types of ingredients, and provides advice on the development of risk assessment strategies consistent with due diligence under existing food regulations. Product specifications, composition and characterisation of standardised and authentic materials, documented history of use and comparison to existing products (taking into account the effect of industrial processing), description of the intended use and consequent exposure are highlighted as key background information on which to base a risk evaluation. The extent of experimental investigation required, such as in vitro, animal, and/or human studies, depends on the adequacy of this information. A decision tree is presented as an aid to determine the extent of data requirements based on product comparison. The ultimate safety in use depends on the establishment of an adequate safety margin between expected exposure and identified potential hazards. Health hazards may arise from inherent toxicities or contaminants of the plant materials, including the mechanism of the intended beneficial effect. A lower safety margin may therefore be expected than for food ingredients or additives where no physiological effects are intended. In rare cases, post launch monitoring programmes may be envisaged to confirm expected exposures and adequacy of the safety margin. This guidance document was elaborated by an expert group of the Natural Toxin Task Force of the European Branch of the International Life Sciences Institute--ILSI Europe and discussed with a wider audience of scientists at a workshop held on 13-15 May 2002 in Marseille, France.

Metformin treatment is associated with a low risk of mortality in diabetic patients with heart failure: a retrospective nationwide cohort study

AIMS/HYPOTHESIS

The safety of metformin in heart failure has been questioned because of a perceived risk of life-threatening lactic acidosis, though recent studies have not supported this concern. We investigated the risk of all-cause mortality associated with individual glucose-lowering treatment regimens used in current clinical practice in Denmark.

METHODS

All patients aged ≥ 30 years hospitalised for the first time for heart failure in 1997-2006 were identified and followed until the end of 2006. Patients who received treatment with metformin, a sulfonylurea and/or insulin were included and assigned to mono-, bi- or triple therapy groups. Multivariable Cox proportional hazard regression models were used to assess the risk of all-cause mortality.

RESULTS

A total of 10,920 patients were included. The median observational time was 844 days (interquartile range 365-1,395 days). In total, 6,187 (57%) patients died. With sulfonylurea monotherapy used as the reference, adjusted hazard ratios for all-cause mortality associated with the different treatment groups were as follows: metformin 0.85 (95% CI 0.75-0.98, p = 0.02), metformin + sulfonylurea 0.89 (95% CI 0.82-0.96, p = 0.003), metformin + insulin 0.96 (95% CI 0.82-1.13, p = 0.6), metformin + insulin + sulfonylurea 0.94 (95% CI 0.77-1.15, p = 0.5), sulfonylurea + insulin 0.97 (95% CI 0.86-1.08, p = 0.5) and insulin 1.14 (95% CI 1.06-1.20, p = 0.0001).

CONCLUSIONS/INTERPRETATION

Treatment with metformin is associated with a low risk of mortality in diabetic patients with heart failure compared with treatment with a sulfonylurea or insulin.

Signaling properties of VEGF receptor-1 and -2 homo- and heterodimers

Vascular endothelial growth factor (VEGF-A) exerts its effects through receptor tyrosine kinases VEGF receptor-1 (VEGFR-1) and VEGFR-2, which are expressed on most endothelial cell types in vitro and in vivo. We have examined VEGF-A-induced signal transduction in porcine aortic endothelial (PAE) cells individually expressing VEGFR-1 or VEGFR-2, and cells co-expressing both receptor types. We show that VEGF-A-stimulated PAE cells co-expressing VEGFR-1 and -2 contain receptor heterodimers. VEGF-A-stimulation of all three cell lines (expressing VEGFR-1, -2 and -1/2) resulted in signal transduction with different efficiencies. Thus, tyrosine phosphorylation of phospholipase Cgamma, and accumulation of inositol polyphosphates were efficiently transduced in the VEGFR-1/2 cells whereas cells expressing VEGFR-1 responded poorly in these assays. In contrast, VEGF-A-induced activation of phosphoinositide 3-kinase and induction of Ca2+ fluxes were transduced well by VEGFR-1 and VEGFR-2 homo- and heterodimers. The pattern of Ca2+ fluxes was unique for each type of VEGF receptor dimer. Our data show that signal transduction induced by VEGF-A is transduced in distinct manners by homo- and heterodimers of VEGF receptors.

Work stress and low emotional support is associated with increased risk of future type 2 diabetes in women

A case-referent study nested within a population-based health survey investigated the associations between psychosocial stress, such as work stress and low emotional support, and future development of type 2 diabetes among occupationally working middle-aged men and women. All participants in a health survey conducted during 1989-2000 (n=33,336) in Umeå in northern Sweden, were included. We identified 191 cases, who were not diabetic initially but were diagnosed with type 2 diabetes after 5.4+/-2.6 years. Two age- and sex-matched referents were selected for each case. Multivariate logistic regression analyses and interaction effects between variables were evaluated. In women, passive or tense working situations were associated with future type 2 diabetes with odds ratios 3.6 (95% confidence interval 1.1-11.7) and 3.6 (1.0-13.3), respectively, and also low emotional support 3.0 (1.3-7.0). These associations were not seen in men. In women, they remained after adjustment for BMI, civil status and educational level, and there were also tendencies for interactions between work stress and low emotional support. In conclusion, work stress and low emotional support may increase the risk of type 2 diabetes in women, but not in men. These findings contribute to our understanding of psychosocial stress as potential risk factors for type 2 diabetes in a Swedish population.

Isolation and characterization of variant IGF-1 as well as IGF-2 from adult human brain

The forms of somatomedin present in the adult human brain have been characterized in this study. Two peptides were purified by acidification, size exclusion chromatography, affinity chromatography, FPLC and HPLC. Structural analysis identified these peptides as the variant form of IGF-1 with a truncated N-terminal region earlier isolated from human fetal brain and IGF-2. The presence of the truncated IGF-1 variant and IGF-2 in the human CNS suggests their role as neuropeptides.

Interleukin-1 in adrenal chromaffin cells

Interleukin-1, first identified as a macrophage factor of importance in infections and inflammation, is a protein with properties of an endogenous pyrogene and lymphocyte activating factor. Occurrence of interleukin-1-like immunoreactivity was demonstrated in the noradrenergic chromaffin cells of the rat and mouse adrenal gland by means of two antisera raised against synthetic peptides corresponding to the amino acid sequences 169-194 and 201-215 of the murine interleukin-1 precursor protein. These antisera also inhibited stimulation of interleukin-2 receptor expression by purified human interleukin-1. Reserpine, which is known to deplete catecholamines, also caused release of the interleukin-1-like immunoreactive material. The interleukin-1 content of the rat adrenal medulla was estimated by radioimmunoassay, and if released the adrenal interleukin-1 pool may result in plasma interleukin-1 levels of about 10(-12). The interleukin-1-immunoreactive material obtained from the rat adrenal gland was characterized as a trypsin-sensitive protein with a molecular weight in the range of 13,000-19,000. This protein fraction stimulated interleukin-2 receptor expression on human T-cells as earlier shown for interleukin-1.

Treatment of acute isolated and combined ruptures of the anterior cruciate ligament. A long-term follow-up study

From a total of 293 patients who had an acute, complete anterior cruciate ligament rupture, we selected all patients (N = 55) who had an anterior cruciate ligament rupture without associated meniscal or ligamentous injuries, and all patients (N = 52) who had an anterior cruciate ligament rupture combined with a rupture, and subsequent primary repair, of the medial collateral ligament. Initially, all patients were assigned to one of two groups: conservative treatment of the anterior cruciate ligament or augmented anterior cruciate ligament repair with the iliotibial band. In the 52 patients who had an anterior cruciate ligament rupture combined with a medial collateral ligament rupture, the associated injuries to the medial collateral ligament and sometimes the posterior oblique ligament, meniscus, and arcuate ligament complex were treated in a similar fashion, without regard to the treatment of the anterior cruciate ligament. Ninety-nine patients (93%) were reexamined 35 to 74 months after the injury, and knee function was evaluated with subjective and objective criteria, including functional tests. Patients who had been treated with augmented anterior cruciate ligament repair had superior stability with better subjective results and returned to strenuous activities more frequently than patients who had undergone conservative treatment. In those patients who had augmented repair, the prognosis did not differ between those who had isolated lesions and those who had combined lesions. Conservative treatment of the anterior cruciate ligament with repair of the medial collateral ligament and other associated injuries, when present, resulted in an almost equally unfavorable outcome for patients with combined and isolated anterior cruciate ligament lesions.

Centrifugal pump and heparin coating improves cardiopulmonary bypass biocompatibility

BACKGROUND

Centrifugal pumps are being used increasingly for short-term extracorporeal circulation purposes such as during heart operations. Whether the centrifugal pump improves the cardiopulmonary bypass biocompatibility has not been fully documented.

METHODS

A roller pump (n = 20) was compared in vivo with a centrifugal pump (n = 20) in groups of patients in which cardiopulmonary bypass circuits that were either totally heparin coated (Carmeda BioActive Surface; n = 20) or uncoated (n = 20) were used. We expected the heparin coating to attenuate blood activation, thus possibly making the comparison of the two pumps easier with respect to their different blood activation potentials. Samples of blood plasma, obtained during cardiopulmonary bypass from low-risk coronary artery bypass grafting patients, were analyzed for hemolysis (plasma haemoglobin), complement activation (C3bc and the terminal complement complex), a complement lytic inhibitor (vitronectin), coagulation activation (fibrinopeptide A), granulocyte activation (lactoferrin), and platelet activation (beta-thromboglobulin).

RESULTS

The concentrations of terminal complement complex, lactoferrin, and beta-thromboglobulin were significantly lower in association with heparin-coated surfaces. The concentration of plasma hemoglobin was significantly lower in association with the centrifugal pump. In uncoated circuits, the beta-thromboglobulin level was significantly higher in association with the roller pump than with the centrifugal pump, but this significant reduction in the beta-thromboglobulin level did not hold true for the heparin-coated circuit group.

CONCLUSIONS

A heparin-coated cardiopulmonary bypass surface reduces the blood activation potential during cardiopulmonary bypass, and the centrifugal pump causes less hemolysis than the roller pump.

Sustained peripheral depletion of amyloid-β with a novel form of neprilysin does not affect central levels of amyloid-β

Lowering levels of peripheral amyloid-β has been proposed as a strategy to reduce plaques in patients with Alzheimer’s disease. Henderson et al. test a modified version of the amyloid-degrading enzyme neprilysin in rats, monkeys and Tg2576 mice. Levels of amyloid-β were reduced in the bloodstream, but not in the CNS.

Alzheimer’s disease is characterized by the accumulation of amyloid deposits in the brain and the progressive loss of cognitive functions. Although the precise role of amyloid-β in disease progression remains somewhat controversial, many efforts to halt or reverse disease progression have focussed on reducing its synthesis or enhancing its removal. It is believed that brain and peripheral soluble amyloid-β are in equilibrium and it has previously been hypothesized that a reduction in peripheral amyloid-β can lower brain amyloid-β, thereby reducing formation of plaques predominantly composed of insoluble amyloid-β; the so-called peripheral sink hypothesis. Here we describe the use of an amyloid-β degrading enzyme, the endogenous metallopeptidase neprilysin, which is fused to albumin to extend plasma half-life and has been engineered to confer increased amyloid-β degradation activity. We used this molecule to investigate the effect of degradation of peripheral amyloid-β on amyloid-β levels in the brain and cerebrospinal fluid after repeated intravenous dosing for up to 4 months in Tg2576 transgenic mice, and 1 month in rats and monkeys. This molecule proved highly effective at degradation of amyloid-β in the periphery but did not alter brain or cerebrospinal fluid amyloid-β levels, suggesting that the peripheral sink hypothesis is not valid and is the first time that this has been demonstrated in non-human primates.

The epidemiology of hepatocellular carcinoma in patients with acute intermittent porphyria

OBJECTIVE

To describe the epidemiology, pathogenesis and clinical features of hepatocellular carcinoma (HCC) in patients with acute intermittent porphyria (AIP).

DESIGN

A retrospective population-based mortality study.

SUBJECTS

All inhabitants who died between 1978-1990 (2122) including 33 with AIP, in two municipalities in northern Sweden with a high prevalence of AIP.

INTERVENTIONS

Death certificates and hospital records were examined. Histological re-examination of paraffin-embedded specimens from patients with HCC was performed and hepatitis B virus content analysed.

RESULTS

HCC was found in 27% of patients with AIP versus 0.2% of the deceased non-AIP subjects, P < 0.0001. HCC was more common in women (men:women 1:2) and in manifest AIP (manifest: latent 2:1). Liver cirrhosis was more common in AIP patients (12%), especially in women, compared with controls (0.5%), P < 0.0001.

CONCLUSIONS

AIP patients seem to have an increased risk of developing HCC. This tumour is more common in patients with manifest AIP and in women, a reversal of the usually reported gender ratio for HCC. No cause for developing HCC other than AIP was found. The pathogenesis may be explained by abnormalities in porphyrin metabolism and by intrinsic production of mutagenic substances, resulting in a condition of systemic overload of oxidative stress, enhancing mutation rate and liver cell injury. Liver cirrhosis appears to be more common in AIP patients and may be a preliminary stage to HCC. All AIP gene carriers aged > or = 55 should be screened for HCC.

The three ZNT8 autoantibody variants together improve the diagnostic sensitivity of childhood and adolescent type 1 diabetes

AIMS

We tested whether autoantibodies to all three ZnT8RWQ variants, GAD65, insulinoma-associated protein 2 (IA-2), insulin and autoantibodies to islet cell cytoplasm (ICA) in combination with human leukocyte antigen (HLA) would improve the diagnostic sensitivity of childhood type 1 diabetes by detecting the children who otherwise would have been autoantibody-negative.

METHODS

A total of 686 patients diagnosed in 1996-2005 in Skåne were analyzed for all the seven autoantibodies [arginin 325 zinc transporter 8 autoantibody (ZnT8RA), tryptophan 325 zinc transporter 8 autoantibody (ZnT8WA), glutamine 325 Zinc transporter 8 autoantibody (ZnT8QA), autoantibodies to glutamic acid decarboxylase (GADA), Autoantibodies to islet-antigen-2 (IA-2A), insulin autoantibodies (IAA) and ICA] in addition to HLA-DQ genotypes.

RESULTS

Zinc transporter 8 autoantibody to either one or all three amino acid variants at position 325 (ZnT8RWQA) was found in 65% (449/686) of the patients. The frequency was independent of age at diagnosis. The ZnT8RWQA reduced the frequency of autoantibody-negative patients from 7.5 to 5.4%-a reduction by 28%. Only 2 of 108 (2%) patients who are below 5 years of age had no autoantibody at diagnosis. Diagnosis without any islet autoantibody increased with increasing age at onset. DQA1-B1(*)X-0604 was associated with both ZnT8RA (p = 0.002) and ZnT8WA (p = 0.01) but not with ZnT8QA (p = 0.07). Kappa agreement analysis showed moderate (>0.40) to fair (>0.20) agreement between pairs of autoantibodies for all combinations of GADA, IA-2A, ZnT8RWQA and ICA but only slight ( < 0.19) agreement for any combination with IAA.

CONCLUSIONS

This study revealed that (1) the ZnT8RWQA was common, independent of age; (2) multiple autoantibodies were common among the young; (3) DQA1-B1(*)X-0604 increased the risk for ZnT8RA and ZnT8WA; (4) agreement between autoantibody pairs was common for all combinations except IAA. These results suggest that ZnT8RWQA is a necessary complement to the classification and prediction of childhood type 1 diabetes as well as to randomize the subjects in the prevention and intervention of clinical trials.