Low total haemoglobin mass, blood volume and aerobic capacity in men with type 1 diabetes

Blood O₂ carrying capacity affects aerobic capacity (VO_2max). Patients with type 1 diabetes have a risk for anaemia along with renal impairment, and they often have low VO_2max. We investigated whether total haemoglobin mass (tHb-mass) and blood volume (BV) differ in men with type 1 diabetes (T1D, n = 12) presently without complications and in healthy men (CON, n = 23) (age-, anthropometry-, physical activity-matched), to seek an explanation for low VO_2max. We determined tHb-mass, BV, haemoglobin concentration ([Hb]), and VO_2max in T1D and CON. With similar (mean ± SD) [Hb] (144 vs. 145 g l^?1), T1D had lower tHb-mass (10.1 ± 1.4 vs. 11.0 ± 1.1 g kg^?1, P < 0.05), BV (76.8 ± 9.5 vs. 83.5 ± 8.3 ml kg^?1, P < 0.05) and VO_2max (35.4 ± 4.8 vs. 44.9 ± 7.5 ml kg^?1 min^?1, P < 0.001) than CON. VO_2max correlated with tHb-mass and BV both in T1D (r = 0.71, P < 0.01 and 0.67, P < 0.05, respectively) and CON (r = 0.54, P < 0.01 and 0.66, P < 0.001, respectively), but not with [Hb]. Linear regression slopes were shallower in T1D than CON both between VO_2max and tHb-mass (2.4 and 3.6 ml kg^?1 min^?1 vs. g kg^?1, respectively) and VO_2max and BV (0.3 and 0.6 ml kg^?1 min^?1 vs. g kg^?1, respectively), indicating that T1D were unable to reach similar VO_2max than CON at a given tHb-mass and BV. In conclusion, low tHb-mass and BV partly explained low VO_2max in T1D and may provide early and more sensitive markers of blood O₂ carrying capacity than [Hb] alone.     

Corticobasal and ataxia syndromes widen the spectrum of C9ORF72 hexanucleotide expansion disease

Recently, a hexanucleotide (GGGGCC) repeat expansion in the first intron of C9ORF72 was reported as the cause of chromosome 9p21‐linked frontotemporal dementia‐amyotrophic lateral sclerosis (FTD‐ALS). We here report the prevalence of the expansion in a hospital‐based cohort and associated clinical features indicating a wider clinical spectrum of C9ORF72 disease than previously described. We studied 280 patients previously screened for mutations in genes involved in early onset autosomal dominant inherited dementia disorders. A repeat‐primed polymerase chain reaction amplification assay was used to identify pathogenic GGGGCC expansions. As a potential modifier, confirmed cases were further investigated for abnormal CAG expansions in ATXN2. A pathogenic GGGGCC expansion was identified in a total of 14 probands. Three of these presented with atypical clinical features and were previously diagnosed with clinical olivopontocerebellar degeneration (OPCD), atypical Parkinsonian syndrome (APS) and a corticobasal syndrome (CBS). Further, the pathogenic expansion was identified in six FTD patients, four patients with FTD‐ALS and one ALS patient. All confirmed cases had normal ATXN2 repeat sizes. Our study widens the clinical spectrum of C9ORF72related disease and confirms the hexanucleotide expansion as a prevalent cause of FTD‐ALS disorders. There was no indication of a modifying effect of the ATXN2 gene.     

The use of aluminium hydroxide as adjuvant modulates the specific antibody response—A Brown Norway rat study with native and denatured cow's milk allergens

There is a need for efficient methods to treat food allergy; however, no immunotherapeutic method has yet been satisfactory due to the high rate of unpredictable severe reactions and the limited efficacy. Therefore, modified versions of food allergens have been suggested as alternatives to the parent proteins for immunotherapy. The aim of the study was to compare the inherent allergenicity of the native and denatured version of the cow's milk proteins β-lactoglobulin and α-lactalbumin, and to study the impact of the use of Al(OH)₃ as an adjuvant. Brown Norway rats were immunized intraperitoneally with either native or denatured β-lactoglobulin or α-lactalbumin, with or without the use of Al(OH)₃ as adjuvant. Antibody responses were analysed in various ways by means of different ELISAs. Both the immunogenicity and the sensitizing capacity of the cow's milk allergens were influenced by their globular folding, with the native version being more allergenic than the denatured counterpart. The native folded proteins mainly raised antibodies against conformational epitope, whereas the denatured versions predominantly raised antibodies against linear epitopes. Most interestingly, the study showed that the use of Al(OH)₃, besides increasing immunogenicity and sensitizing capacity of the cow's milk allergens, caused a modification of the specificity of the antibodies raised against the native version of the proteins. Adsorption of the native forms of the allergens to Al(OH)₃ caused a significant greater proportion of antibodies raised against linear epitopes, stressing that the adsorption induced a partly unfolding of the proteins. This may have implications for IT safety and efficacy.     

High target attainment for β-lactam antibiotics in intensive care unit patients when actual minimum inhibitory concentrations are applied

Patients in the intensive care unit (ICU) are at risk for suboptimal levels of β-lactam antibiotics, possibly leading to poor efficacy. Our aim was to investigate whether the actual minimum inhibitory concentration (MIC) compared to the more commonly used arbitrary epidemiological cut-off values (ECOFFs) would affect target attainment in ICU patients on empirical treatment with broad-spectrum β-lactam antibiotics and to identify risk factors for not reaching target. In a prospective, multicenter study, ICU patients ≥18 years old and treated with piperacillin/tazobactam, meropenem, or cefotaxime were included. Clinical and laboratory data were recorded. Serum trough antibiotic levels from three consecutive days were analyzed by liquid chromatography–mass spectrometry (LC-MS). The target was defined as the free trough concentration above the MIC (100% fT_>MIC). MIC_ECOFF was used as the target and, when available, the actual MIC (MIC_ACTUAL) was applied. The median age of the patients was 70 years old, 52% (58/111) were males, and the median estimated glomerular filtration rate (eGFR) was 48.0 mL/min/1.73 m². The rate of patients reaching 100% fT?>?MIC_ACTUAL was higher (89%, 31/35) compared to the same patients using MIC_ECOFF (60%, p?=?0.002). In total, 55% (61/111) reached 100% fT?>?MIC_ECOFF. Increased renal clearance was independently associated to not reaching 100% fT?>?MIC_ECOFF. On repeated sampling, >77% of patients had stable serum drug levels around the MIC_ECOFF. Serum concentrations of β-lactam antibiotics vary extensively between ICU patients. The rate of patients not reaching target was markedly lower for the actual MIC than when the arbitrary MIC based on the ECOFF was used, which is important to consider in future studies.     

Interleukin-17A during Local and Systemic Staphylococcus aureus-Induced Arthritis in Mice

Staphylococcus aureus is one of the dominant pathogens that induce septic arthritis in immunocompromised hosts, e.g., patients suffering from rheumatoid arthritis treated with immunosuppressive drugs. S. aureus-induced arthritis leads to severe joint destruction and high mortality despite antibiotic treatment. Recently, interleukin-17A (IL-17A) has been discovered to be an important mediator of aseptic arthritis both in mice and humans, but its function in S. aureus-induced arthritis is largely unknown. Here, we investigated the role of IL-17A in host defense against arthritis following systemic and local S. aureus infection in vivo. IL-17A knockout mice and wild-type mice were inoculated systemically (intravenously) or locally (intra-articularly) with S. aureus. During systemic infection, IL-17A knockout mice lost significantly more weight than the wild-type mice did, but no differences were found in the mortality rate. The absence of IL-17A had no impact on clinical arthritis development but led to increased histopathological erosivity late during systemic S. aureus infection. Bacterial clearance in kidneys was increased in IL-17A knockout mice compared to the level in wild-type mice only 1 day after bacterial inoculation. During systemic S. aureus infection, serum IL-17F protein levels and mRNA levels in the lymph nodes were elevated in the IL-17A knockout mice compared to the level in wild-type mice. In contrast to systemic infection, the IL-17A knockout mice had increased synovitis and erosions and locally decreased clearance of bacteria 3 days after local bacterial inoculation. On the basis of these findings, we suggest that IL-17A is more important in local host defense than in systemic host defense against S. aureus-induced arthritis.Patients with rheumatoid arthritis (RA) are susceptible to bacterial joint infections as a result of immunosuppressive treatments and the disease per se (24). The most common agent causing joint infections is Staphylococcus aureus, a microbe that can also cause sepsis. S. aureus-induced arthritis is a severe problem with a mortality rate of 5 to 20%, and 25 to 70% of affected patients develop permanent joint damage despite treatment (24). Although substantial efforts have been made to understand the immunological mechanisms that lead to S. aureus-induced joint destruction, it remains difficult to treat the infection (by maintaining the host''s ability to clear bacteria) while simultaneously limiting the joint destruction (by suppressing the immunological response). Thus, there is a need to identify new ways to treat RA that do not increase the severity of S. aureus-induced arthritis following infection.Recent evidence from humans and mice suggesting that the proinflammatory cytokine interleukin-17A (IL-17A) is an important player in RA (3, 19, 21) prompted an ongoing clinical trial of IL-17A-blocking antibodies to treat RA (6). Interleukin-17A was first described in 1993, but it was not until 2005, when Harrington et al. (8) described the unique Th17 subset, that the relevance of this cytokine was widely recognized among immunologists (5, 13, 15). Interleukin-17A appears to play a key role in host defense against local Gram-negative extracellular bacterial infections (4, 7, 9, 10, 17, 22, 29, 30) and local S. aureus infections (18) by inducing the production of neutrophil-mobilizing chemokines and growth factors and the subsequent mobilization of neutrophils (5, 13, 15, 16). Importantly, Ishigame et al. have recently shown that genetical knockout of IL-17A plus IL-17F (double knockout) in mice has very little impact on the general outcome of systemic S. aureus infection, measured as mortality and bacterial clearance at a single time point after bacterial inoculation compared with wild-type mice (11). However, in that study, the respective roles of IL-17A and -17F in S. aureus-induced arthritis were not specifically addressed (11), and this aspect is the main focus of this study. S. aureus-induced arthritis is a great concern in RA (24), and the first phase I study using IL-17A-blocking antibodies as a treatment in RA has recently been published (6). Thus, it is clinically important to determine whether reduced IL-17A levels in RA patients would have a detrimental effect on S. aureus-induced arthritis.It is well-known that, within the IL-17 family, IL-17F is the cytokine that shares the greatest structural and functional homology with IL-17A (5, 15). Both IL-17A and IL-17F exist as homodimers or as IL-17A-IL-17F heterodimers and bind to the IL-17 receptor A (IL-17RA)-IL-17RC receptor complex (28). Furthermore, these three IL-17 cytokines may exert similar biological effects, in particular with reference to the local mobilization of neutrophils (23). Studies of healthy mice have also shown that IL-17A is capable of inhibiting the production of IL-17F under certain conditions, through a IL-17RA-dependent mechanism (27). Thus, IL-17A and IL-17F seem to be functionally linked.In the present study, we characterized the kinetics of systemic and local S. aureus infections in the presence and absence of IL-17A in mice. For this purpose, we used IL-17A knockout mice (21) and wild-type control mice in our well-established mouse models of systemic and local S. aureus-induced arthritis (1) and assessed specific aspects of arthritis and more-general clinical outcomes. Using this approach, we obtained evidence that bacterial clearance, cytokine pattern, and degree of arthritis vary over time during systemic S. aureus infection and that IL-17A plays a more important role in local host defense than in systemic host defense against S. aureus-induced arthritis.     

Elevated serum 8-oxo-dG in hemodialysis patients: a marker of systemic inflammation?

Does inflammation, as assessed by high sensitivity C-reactive protein (hs-CRP), in patients with end-stage renal disease (ESRD) tightly associate with increased serum levels of 8-oxo-7,8-dihydro-2'-deoxyguanosine (8- oxo-dG)? Increased oxidative stress and inflammation have both been highlighted among several nontraditional risk factors for cardiovascular disease, which is the main cause of mortality in ESRD patients. In contrast to oxidative stress effects on proteins and lipids, DNA base damage has not been well demonstrated in ESRD. Two groups of hemodialysis patients were studied, one group with persistent inflammation (n = 13, with constant elevation of CRP > 10 mg/L for 6 months) and one group of noninflamed patients (n = 19, with constant CRP < 10 mg/L for 6 months). Serum 8-oxo-dG was significantly elevated in persistent inflammation in comparison to noninflamed patients. At an individual level, a significant correlation was found between serum 8-oxo-dG and hsCRP. Extracellular 8-oxo-dG leads to intracellular oxidative damage on the nucleotide pool, thus providing a sensitive marker for inflammatory response. Serum levels of 8-oxo-dG, in combination with other inflammatory markers, serve as useful diagnostic tools for identification of patients in risk for inflammatory complications.     

Altered distribution and levels of cathepsinD and cystatins in amyotrophic lateral sclerosis transgenic mice: possible roles in motor neuron survival

In amyotrophic lateral sclerosis (ALS) there is a selective degeneration of motor neurons leading to muscle paralysis and death. The mechanism underlying cell demise in ALS is not fully understood, but involves the activation of different proteolytic enzymes, including the caspase family of cysteine proteases. We have here studied whether other proteases, such as the cathepsins, residing in lysosomes, and the cathepsin inhibitors, cystatinB and -C are changed in ALS. The expression and protein levels of the cathepsinB, -L and -D all increased in the spinal cord in ALS mice, carrying the mutant copper/zinc superoxide dismutase (SOD1) gene. At the cellular level, cathepsinB and -L were present in ventral motor neurons in controls, but in the ALS mice cathepsinB was also expressed by glial fibrillary acidic protein (GFAP) positive astrocytes. The distribution of the aspartic protease, cathepsinD also changed in ALS with a loss of the lysosomal staining in motor neurons. Inhibition of caspases by means of X-chromosome-linked inhibitor of apoptosis protein (XIAP) overexpression did not inhibit cleavage of cathepsinD in ALS mice, suggesting a caspase-independent pathway. Expression of cystatinB and -C increased slightly in the ALS spinal cords. Immunostaining showed that in ALS, cystatinC was present in motor neurons and in GFAP positive astrocytes. CystatinB that is a neuroprotective factor decreased in motor neurons in ALS but was expressed by activated microglial cells. The observed changes in the levels and distributions of cathepsinD and cystatinB and-C indicate a role of these proteins in the degeneration of motor neurons in ALS.     

Access to contraceptive services among unmarried young people in the north-east of China

Objective The concerns about the potential threats of human immunodeficiency virus (HIV) infection and acquired immunodeficiency syndrome (AIDS) have increased, since, in China, there is a lack of sexual education and condom use is rare. A community-based survey was conducted in September 2001 in Changchun city among 1227 unmarried young people aged 15-24 years (619 males and 608 females) to assess risky sexual practices and the obstacles to accessing appropriate contraceptive and other services. Method The study comprised a survey employing self-administered questionnaires, as well as key informant interviews, focus group discussions and in-depth interviews. This paper investigates the factors associated with young people's access to contraceptive services. Results Results showed that 16% of young people had experienced premarital sexual intercourse and, among them, only 48.2% used contraceptive methods during the first sexual intercourse; 29.9% used a condom. Drug stores were the main source of contraceptives. Conclusions While data are sparse, findings suggest that the hostile and judgmental attitudes of providers, as well as the lack of counseling and privacy, were the key obstacles that unmarried youth encountered in their search for contraceptive services. Findings suggest the need for a reorientation of the contraceptive services to focus on unmarried youth, and generally to make contraceptive services more accessible to young people.