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Background: Ragweed is an invasive, highly allergenic weed predicted to expand its habitat with warming global temperatures. Several Ambrosia species have been identified in South Africa for well over a century; however, its presence remained undetected by allergists and aerobiologists until the development of an extensive aerospora monitoring system across South African urban areas since 2019. This paper presents the inventory of preliminary investigation of the Ambrosia airborne pollen and the taxonomic identification of ragweed species. Methods: Burkard volumetric spore traps for collecting pollen samples are set up in 9 South African cities (Johannesburg, Cape Town, Pretoria, Kimberley, Durban, Potchefstroom, Ermelo, Bloemfontein, and Gqeberha). Light microscopic identification was combined with environmental DNA metabarcoding analysis to confirm the species level of airborne Ambrosia at selected monitoring stations. Ragweed sensitisation was examined in Cape Town between February 2019 and February 2024, using Allergy Xplorer (ALEX2) multicomponent allergen array. Results: Ambrosia pollen was detected in 5 aerobiological monitoring stations over the sampling period (Durban, Kimberley, Pretoria, Potchefstroom, Johannesburg). Periods of 4 consistent pollination years were observed in Kimberley (min: 1; max: 16 p.g/m3) and Durban (min: 26; max: 66 p.g/m3). In Pretoria, ragweed pollen was detected for 2 years (2020–2021; 2022–2023) with average total annuals (5-17 p.g/m3). A peak flowering period between March and April was observed in Potchefstroom, and several ragweed pollen peaks were present between the end of December and the beginning of May in Durban. The highest number of Ambrosia pollen grains was recorded in Potchefstroom, with 308 grains, and a maximum peak of 47 p.g/m3. eDNA metabarcoding confirmed the presence of Ambrosia artemisiifolia and A.trifida species. The overall prevalence of Ambrosia-sensitisation amongst 673 tests (age range 7–72 years) was 8.2% (55/673), with no significant difference in sensitisation patterns between age groups. Conclusion: Our study confirms the need to monitor the spread of ragweed, and an increasing awareness of Ambrosia as an allergen of concern in Southern Africa. Extension of aerobiological networks and testing for Ambrosia sensitisation across urban and rural sites will be required.

Objective: Hyperglucagonemia is present in many forms of diabetes and contributes to hyperglycemia, and glucagon suppression can ameliorate diabetes in mice. Leptin, a glucagon suppressor, can also reverse diabetes in rodents. Lipid nanoparticle (LNP) delivery of small interfering RNA (siRNA) effectively targets the liver and is in clinical trials for the treatment of various diseases. We compared the effectiveness of glucagon receptor (Gcgr)-siRNA delivered via LNPs to leptin in two mouse models of diabetes. Methods: Gcgr siRNA encapsulated into LNPs or leptin was administered to mice with diabetes due to injection of the β-cell toxin streptozotocin (STZ) alone or combined with high fat diet (HFD/STZ). Results: In STZ-diabetic mice, a single injection of Gcgr siRNA lowered blood glucose levels for 3 weeks, improved glucose tolerance, and normalized plasma ketones levels, while leptin therapy normalized blood glucose levels, oral glucose tolerance, and plasma ketones, and suppressed lipid metabolism. In contrast, in HFD/STZ-diabetic mice, Gcgr siRNA lowered blood glucose levels for 2 months, improved oral glucose tolerance, and reduced HbA1c, while leptin had no beneficial effects. Conclusions: While leptin may be more effective than Gcgr siRNA at normalizing both glucose and lipid metabolism in STZ diabetes, Gcgr siRNA is more effective at reducing blood glucose levels in HFD/STZ diabetes.

Background: The hormone leptin is an important regulator of metabolic homeostasis, able to inhibit food intake and increase energy expenditure. Leptin can also independently lower blood glucose levels, particularly in hyperglycemic models of leptin or insulin deficiency. Despite significant efforts and relevance to diabetes, the mechanisms by which leptin acts to regulate blood glucose levels are not fully understood. Scope of review: Here we assess literature relevant to the glucose lowering effects of leptin. Leptin receptors are widely expressed in multiple cell types, and we describe both peripheral and central effects of leptin that may be involved in lowering blood glucose. In addition, we summarize the potential clinical application of leptin in regulating glucose homeostasis. Major conclusions: Leptin exerts a plethora of metabolic effects on various tissues including suppressing production of glucagon and corticosterone, increasing glucose uptake, and inhibiting hepatic glucose output. A more in-depth understanding of the mechanisms of the glucose-lowering actions of leptin may reveal new strategies to treat metabolic disorders.

Objective: It has been thought that the depletion of insulin is responsible for the catabolic consequences of diabetes; however, evidence suggests that glucagon also plays a role in diabetes pathogenesis. Glucagon suppression by glucagon receptor (Gcgr) gene deletion, glucagon immunoneutralization, or Gcgr antagonist can reverse or prevent type 1 diabetes in rodents suggesting that dysregulated glucagon is also required for development of diabetic symptoms. However, the models used in these studies were rendered diabetic by chemical- or immune-mediated β-cell destruction, in which insulin depletion is incomplete. Therefore, it is unclear whether glucagon suppression could overcome the consequence of the complete lack of insulin. Methods: To directly test this we characterized mice that lack the Gcgr and both insulin genes (GcgrKO/InsKO). Results: In both P1 pups and mice that were kept alive to young adulthood using insulin therapy, blood glucose and plasma ketones were modestly normalized; however, mice survived for only up to 6 days, similar to GcgrHet/InsKO controls. In addition, Gcgr gene deletion was unable to normalize plasma leptin levels, triglycerides, fatty acids, or hepatic cholesterol accumulation compared to GcgrHet/InsKO controls. Conclusion: Therefore, the metabolic manifestations associated with a complete lack of insulin cannot be overcome by glucagon receptor gene inactivation. Author Video: Author Video Watch what authors say about their articles Keywords: Mice, Type 1 diabetes, Insulin, Glucagon, Glucose metabolism, Lipid metabolism

The assessment of fish diversity is crucial for effective conservation and management strategies, especially in ecologically sensitive regions such as marine protected areas. This study contrasts the effectiveness of environmental DNA (eDNA) metabarcoding analysis employing Nanopore technology with compare beam trawl surveys at the Sylt Outer Reef, a Natura 2000 site in the North Sea, Germany. Out of the 17 fish species caught in a bottom trawl (using a 3m beam trawl), 14 were also identified through eDNA extracted from water samples. The three species not detected in the eDNA results were absent because they lacked representation in public DNA databases. The eDNA method detected twice as many fish species as the beam trawl, totalling 36 species, of which 14 were also detected by the trawl. Additionally, the selection of primers (Mifish) facilitated the identification of one marine mammal species, the harbour porpoise. In conclusion, the findings underscore the potential of eDNA coupled with MinION sequencing (Long read technology) as a robust tool for biodiversity assessment, surpassing traditional methods in detecting species richness., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Knowledge about the cumulative impacts of anthropogenic activities and environmental conditions on marine ecosystems is incomplete and details are lacking. Compositional community changes can occur along gradients, and community data can be used to assess the state of community resilience against combined impacts of variables representing human pressures and environmental conditions. Here we use a machine learning approach, i.e., Gradient Forest, to identify explanatory variable thresholds and select relevant epibenthic fauna and demersal fish species, which can be used to inform an integrated management of multiple human pressures and conservation planning in the southern North Sea. We show that a broad selection of anthropogenic and environmental variables, such as natural disturbance of the seafloor and euphotic depth, determined community composition thresholds of 67 epibenthic fauna and 39 demersal fish species along environmental conditions and human pressure gradients in the southern North Sea between 2010 and 2020. This has the potential to inform resilience assessments under the Marine Strategy Framework Directive to promote and retain a good environmental status of marine ecosystems., Competing Interests: Declaration of competing interest All authors confirm there are no known conflicts of interest associated with this publication and funding by BMBF did not influence the outcome., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Artificial intelligence (AI) for luminal gastrointestinal endoscopy is rapidly evolving. To date, most applications have focused on colon polyp detection and characterization. However, the potential of AI to revolutionize our current practice in endoscopy is much more broadly positioned. In this review article, the Authors provide new ideas on how AI might help endoscopists in the future to rediscover endoscopy practice., (Copyright © 2020. Published by Elsevier Ltd.)

Sialic acid-binding Ig-like lectin (Siglec) receptors are linked to neurodegenerative processes, but the role of sialic acids in physiological aging is still not fully understood. We investigated the impact of reduced sialylation in the brain of mice heterozygous for the enzyme glucosamine-2-epimerase/N-acetylmannosamine kinase (GNE+/-) that is essential for sialic acid biosynthesis. We demonstrate that GNE+/- mice have hyposialylation in different brain regions, less synapses in the hippocampus and reduced microglial arborization already at 6 months followed by increased loss of neurons at 12 months. A transcriptomic analysis revealed no pro-inflammatory changes indicating an innate homeostatic immune process leading to the removal of synapses and neurons in GNE+/- mice during aging. Crossbreeding with complement C3-deficient mice rescued the earlier onset of neuronal and synaptic loss as well as the changes in microglial arborization. Thus, sialic acids of the glycocalyx contribute to brain homeostasis and act as a recognition system for the innate immune system in the brain., (Copyright © 2020 The Authors. Published by Elsevier Inc. All rights reserved.)

Polysialic acid (polySia) is widely investigated in various biopharmaceutical applications (e.g. treatment of inflammatory neurodegenerative diseases), whereby a certain polySia chain length with an average degree of polymerization 20 (polySia avDP20) shows most promising effects. In this study, a rapid analytical method using a HPLC and charged aerosol detector (CAD) for the direct chain length characterization of biopharmaceutically relevant polySia was developed. It was evaluated as a fast alternative to the commonly used 1,2-diamino-4,5-methylenedioxybenzene (DMB) HPLC application. In contrast to HPLC-FLD, the CAD-application provides the actual chain length of polySia within ∼3 h. The reliability of the HPLC-CAD was evaluated with a commercial reference sample of known chain length and biotechnologically produced LC polySia (long chain polySia with a DP ∼130). Moreover, HPLC-CAD was successfully applied in the direct detection of oligo- and polySia until DP ∼65 and can be used to monitor the thermal hydrolysis and subsequent chromatographic isolation of polySia avDP20 (average degree of polymerization 20) without DMB sample derivatization. In addition, CAD was successfully applied for polySia quantification using a modified elution gradient. It was tested as a fast alternative to commonly used thiobarbituric acid (TBA) assay. A differentiation between LC polySia and smaller, hydrolysed polySia chains was intended and possible. For LC polySia and polySia avDP20, a quadratic relation between polySia mass-concentration and CAD signal was observed. In case of LC polySia, a quadratic dependency with a determination coefficient of R 2  = 0.99 in a broad concentration range between 0.025 and 15 mg mL -1 was determined. Quantification of polySia avDP20 was found to have quadratic dependency with a determination coefficient of R 2  = 0.99 in a concentration range between 0.02 and 0.25 mg mL -1 . The HPLC-CAD was tested for quantification with polySia references of known concentration and showed high accordance with a concentration deviation ≤6.7%. The CAD quantification method was also applied in the polySia avDP20 production process and was compared to the TBA assay. Results of a correlation plot showed a high determination coefficient of R 2  = 0.98. Overall, HPLC-CAD analysis was successfully tested as a suitable characterization and quantification application in the biopharmaceutical production of polySia., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Background: Children born preterm are at high risk of developmental delay in various cognitive domains. Moreover, problems in social interaction are more frequently reported in preterm children than in their full-term peers. These difficulties can be observed at two years of age and seem to persist until school age. Although closely linked to social acceptance, remarkably little research has focused on social-cognitive skills such as Theory of Mind in preterm children., Aim: The aim of the current study was to assess Theory-of-Mind development in preterm (n = 34) and full-term (n = 38) children over the course of two years., Methods: A Theory-of-Mind scale was administered at the children's age of 3, 4, and 5 years, and we additionally assessed and controlled for general cognitive development., Results: At the age of 3, mean Theory-of-Mind scores were 1.23 (SD = 0.65) for preterm and 1.58 (SD = 0.76) for full-term children. By the age of 5, preterm children's performance (M = 3.50, SD = 1.16) was similar to that of full-term children (M = 3.52, SD = 0.98), revealing a significant interaction effect between birth status and time of measurement, F(1, 44.424) = 4.76, p = .035., Conclusion: The interaction effect indicates that preterm children show a delay rather than a general deficit in Theory-of-Mind development. Mechanisms underlying this course of development are still unknown. To examine why problems in social interaction persist despite improving Theory-of-Mind abilities, future research should extend the focus to implicit mental reasoning in preterm children., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Introduction: Gastroparesis (GP) is defined as delayed gastric emptying (GE) without any obstruction of the pylorus. It can be divided into idiopathic, diabetic, post surgical and rare causes. Electronic gastric stimulation (EGS) - Enterra Medtronic™ - is a part of GP therapy. Although its positive impact has been reported in open label trials, randomized controlled trials failed in demonstrating a positive outcome. The aim of this pilot study was to establish a reliable prediction for permanent gastric stimulation., Patients and Procedure: 6 female patients underwent laparoscopic implantation of 2 temporary electrodes. The Enterra™ system was connected and taped to the skin. Baseline and postoperative gastroparesis cardinal symptom index (GCSI), a validated index for GP therapy, was assessed. Response to EGS was defined as a 50% decrease of baseline GCSI., Results: 4 of 6 patients responded to temporary EGS. 3 of 4 responders underwent permanent implantation. 1 non-responder received a permanent Enterra™ at another institution. After a median follow up time of 9months the responder group GCSI remained low, whereas the non-responder GCSI had increased. Moreover, the health care system was saved € 30,678.03 by this test stimulation concept., Conclusion: Laparoscopic implantation of a temporary EGS system predicts the outcome of permanent gastric stimulation and is cost-saving., (Copyright © 2018 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved.)

The genetic incorporation of unnatural amino acids (UAAs) into proteins by amber suppression technology provides unique avenues to study protein structure, function and interactions both in vitro and in living cells and organisms. This approach has been particularly useful for studying mechanisms of epigenetic chromatin regulation, since these extensively involve dynamic changes in structure, complex formation and posttranslational modifications that are difficult to access by traditional approaches. Here, we review recent achievements in this field, emphasizing UAAs that help to unravel protein-protein interactions in cells by photo-crosslinking or that allow the biosynthesis of proteins with defined posttranslational modifications for studying their function and turnover in vitro and in cells., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Full-coverage spatial data of occurrence and a detailed description of habitat requirements of epibenthic communities are needed in many conservation and management contexts. In the North Sea the focus has so far been on small benthic infauna, whereas structure and ecosystem functions of larger epifaunal communities have been largely ignored. This study provides a comprehensive analysis of epibenthic community structure in the south-eastern North Sea, including a detailed inventory of species, diversity and spatially contiguous distribution of communities. Data from nearly 400 stations were compiled for the study, enabling us to describe epibenthic community structure at unprecedented spatial resolution. Eight distinct epibenthic communities were found in the south-eastern North Sea by using multivariate analysis. Distribution modelling with eight environmental variables (bottom temperature and salinity, temperature differences between summer and winter, mud content of sediments, maximum bottom shear stress, stratification, water depth and annual primary production) and one human pressure (fishing effort) was used to extrapolate probable spatial distributions and to identify associated habitat characteristics of the communities in the south-eastern North Sea. Three large epibenthic communities "Coast", "Oysterground" and "Tail End" reflect a gradual habitat change from the coast towards offshore regions, expressed in gradients of bottom salinity, seasonal temperature differences and stratification as the dominant environmental factors. Five smaller communities ("Amrum Bank", "Frisian Front", "Deeps", "Dogger Bank" and "Dogger Slope") outline specific habitats in the south-eastern North Sea. The "Dogger Slope" community has not been recognized before, but has a predicted spatial extent of 7118 km 2 . Due to the high occurrence of long-lived, sessile species such as sponges this community is very sensitive to demersal fishing., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Worldwide, colorectal cancer is the third commonest cancer. Over 90% follow an adenoma-to-cancer sequence over many years. Colonoscopy is the gold standard method for cancer screening and early adenoma detection. However, considerable variation exists between endoscopists' detection rates. This review considers the effects of different endoscopic techniques on adenoma detection. Two areas of technological interest were considered: (1) optical technologies and (2) mechanical technologies. Optical solutions, including FICE, NBI, i-SCAN and high definition colonoscopy showed mixed results. In contrast, mechanical advances, such as cap-assisted colonoscopy, FUSE, EndoCuff and G-EYE™, showed promise, with reported detections rates of up to 69%. However, before definitive recommendations can be made for their incorporation into daily practice, further studies and comparison trials are required., (Copyright © 2017 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved.)

During eukaryotic cell division, nuclear chromatin undergoes marked changes with respect to shape and degree of compaction. Although already significantly compacted during interphase, upon entry into mitosis chromatin further condenses and individualizes to discrete chromosomes that are captured and moved independently by the mitotic spindle apparatus. Once segregated by the spindle, chromatin decondenses to re-establish its interphase structure competent for DNA replication and transcription. Although cytologically described a long time ago, the underlying molecular mechanisms of mitotic chromatin condensation and decondensation are still ill-defined. Here we summarize our current knowledge of mitotic chromatin restructuring and recent progress in the field., (Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Gastroesophageal reflux disease (GERD) is a diagnosis applicable to "all individuals who are exposed to the risk of physical complications from gastroesophageal reflux, or who experience clinically significant impairment of health related well being (quality of life) due to reflux related symptoms, after adequate reassurance of the benign nature of their symptoms". It remains, predominantly, a symptom-based diagnosis, confirmed clinically by a response to acid suppression therapy although it is accompanied by demonstrable increases in acid exposure on esophageal pH-metry and by endoscopic and histological changes. Standard white light endoscopy permits diagnosis of erosive reflux disease (ERD) which, if present, should be graded for severity using the Los Angeles classification system. However, the role of endoscopy in clinical practice is, primarily, to evaluate patients with persistent symptoms, despite medical therapy, or to investigate alarm features and exclude complications such as Barrett' oesophagus which should be assessed using the Prague C & M criteria. Newer endoscopic techniques allow detection of 'minimal change' GERD lesions and Barrett's oesophagus-associated dysplastic or neoplastic lesions; however, none of the newer techniques has been validated for routine clinical practice. There is an increasing recognition that histology in GERD may provide useful diagnostic information, in part to exclude other lesions, such as eosinophilic oesophagitis, intestinal metaplasia and dysplasia or malignancy and, in part, to identify changes, such as basal cell hyperplasia, papillary elongation and, most recently, dilated intercellular spaces, that are consistent with GERD. However, more widespread incorporation of histology into the clinical management of GERD will require a standardized biopsy protocol and efforts to minimise interobserver differences in the identification of GERD-related histological changes., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

Routine endoscopic imaging of the small bowel is performed with videoendoscopic white light technology. However, currently there are many new methods that improve our visual acuity when evaluating the small bowel mucosa. These methods are collectively called "advanced endoscopic imaging". These imaging methods include high-definition white light endoscopy, standard and dye-less or "virtual" chromoendoscopy, magnification endoscopy and confocal laser endomicroscopy. Regardless of the method used to image the small bowel the endosocopist needs to pay attention to detail and focus on three essential aspects: a) the shape of the lesion, b) the superficial mucosal detail (i.e. "pit pattern") and c) the submucosal vascular pattern. This review describes advances in the endoscopic imaging methods to study the small bowel., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

The signal regulatory protein-beta1 (SIRPbeta1) is a DAP12-associated transmembrane receptor expressed in a subset of hematopoietic cells. Recently, it was shown that peritoneal macrophages express SIRPbeta1, which positively regulated phagocytosis. Here, we found that SIRPbeta1 was up-regulated and acted as a phagocytic receptor on microglia in amyloid precursor protein J20 (APP/J20) transgenic mice and in Alzheimer's disease (AD) patients. Interferon (IFN)-gamma and IFN-beta stimulated gene transcription of SIRPbeta1 in cultured microglia. Activation of SIRPbeta1 on cultured microglia by cross-linking antibodies induced reorganization of the cytoskeleton protein beta-actin and suppressed lipopolysaccharide-induced gene transcription of tumor necrosis factor-alpha and nitric oxide synthase-2. Furthermore, activation of SIRPbeta1 increased phagocytosis of microsphere beads, neural debris, and fibrillary amyloid-beta (Abeta). Phagocytosis of neural cell debris and Abeta was impaired after lentiviral knockdown of SIRPbeta1 in primary microglial cells. Thus, SIRPbeta1 is a novel IFN-induced microglial receptor that supports clearance of neural debris and Abeta aggregates by stimulating phagocytosis.

Damage to neurites with transection of axons and spheroid formation is commonly noted in the central nervous system during viral and autoimmune diseases such as multiple sclerosis, but it remains open whether such changes are caused primarily by immune mechanisms or whether they are secondary to inflammation. The present experiments explored whether neurites can be directly attacked by cytotoxic T lymphocytes (CTLs). Cultured murine neurons induced by interferon-gamma and tetrodotoxin to express major histocompatibility complex class I were pulsed with a dominant peptide of the lymphochoriomeningitis virus envelope glycoprotein (GP33) and then confronted with GP33-specific CD8(+) CTLs. Within 3 hours the neurites developed cytoskeleton breaks with adjacent solitary neuritic spheroids, as documented by confocal examination of the cytoskeletal marker beta-tubulin III. At the same time cytoskeleton staining of the neuronal somata showed no damage. The CTLs selectively attacked neurites and induced segmental membrane disruption 5 to 30 minutes after the establishment of peptide-specific CTL-neurite contact, as directly visualized by live confocal imaging. Thus, major histocompatibility complex class I/peptide-restricted CD8(+) T lymphocytes can induce lesions to neurites, which might be responsible for axonal damage during neuroinflammatory diseases.

From January 1989 until October 1993, 102 patients with 103 distal radius fractures were included in a prospective study with the Pennig wrist fixator (Orthofix, Srl, Italy). 90.5% of these patients were reviewed with a minimum follow-up of 12 months. Using the functional outcome score according to Gartland and Werley, we obtained 41% excellent, 46% good, 10% fair and 3% poor results. Additional procedures such as K-wires, bone grafting or radio-ulnar stabilizations were carried out in 61% of cases. The complications included five fixator displacements, four of which happened with the prototype used until the first half of 1990. Two major pin-track-infections required surgical intervention, three patients in the beginning of the series encountered irritations of the superficial radial nerve, one pin cut out of the second metacarpal bone and one patient sustained algodystrophy. The results show the significance of an anatomical reduction, the restoration of the radial length seems to be of special importance to obtain good functional outcome. This can not always be achieved with the fixator alone; often additional procedures are required in order to obtain an anatomical joint reconstruction. The advantage of this fixator lies in its lightweight and small-size design as well as in its easy application technique and the possibility to carry out the reduction after mounting the fixator with the double ball joint centered on the fracture level and the carpus.

Based on its relationship to very-long-chain acyl-CoA synthetase (VLACS), we have cloned and identified a novel, VLACS-related (VLACSR) cDNA from mouse liver. The 2067-bp open reading frame encodes a 689-amino-acid protein with a predicted molecular mass of 76.2 kDa. The carboxy-terminal 500 amino acids of VLACSR show 48% identity and 70% similarity to mouse VLACS and 43% identity and 60% similarity to mouse fatty acid transporter (FATP), respectively. In addition, a partial cDNA of the human VLACSR ortholog was identified. By Northern blot analysis, a 2.6-kb VLACS mRNA was highly abundant only in mouse liver. Low levels of shorter mRNAs were present in brain, lung, testes, and spleen (2.5 kb) and in skeletal muscle (2.2 kb). In heart, but not in kidney, transcripts undetectable by Northern blot analysis could be demonstrated by RT PCR. Southern blot analysis indicated single-copy VLACSR genes in the mouse and human genomes., (Copyright 1998 Academic Press.)

A fast and simple fibrinogen determination is presented, based on the ammonium sulfate precipitation of fibrinogen. The nature of the precipitated material is investigated by means of immunoelectrophoresis. A comparison is made with a paper electrophoretic method, and a method based on the clotting properties of fibrinogen. The linearity, the within-run precision and normal values, obtained by this method are given. An advantage over other well-known methods is the use of a serum blank instead of a plasma blank without reagent. In this way all interfering substances are detected immediately and simple subtraction of blank readings from sample readings gives true fibrinogen values. The clinical application with respect to the acute phase of inflammation is discussed.

Nephelometric, turbidimetric and radial immunodiffusion methods are described, which permit valid, reproducible determination of human IgM and IgG by weight. Subgroups of IgM, 7S-IgM and subclasses of IgG did not interfere with these methods. For IgG the International Unit represented a constant weight quantity in agreement with official WHO estimations. For IgM the IU was not constant and much lower values are found. It is therefore suggested that the IU should be abolished for human IgM and IgG. Absolute values for IgM levels are presented for both sexes and for age groups in the range of 5-80 years. The figures showed significant variation with sex and age.