Marked increase of the astrocytic marker S100B in the cerebrospinal fluid of HIV-infected patients on LPV/r-monotherapy

Objective: To determine changes of cerebrospinal fluid (CSF) biomarkers of patients on monotherapy with lopinavir/ritonavir. Design: The Monotherapy Switzerland/Thailand study (MOST) trial compared monotherapy with ritonavir-boosted lopinavir with continued therapy. The trial was prematurely stopped due to virological failure in six patients on monotherapy. It, thus, offers a unique opportunity to assess brain markers in the early stage of HIV virological escape. Methods: Sixty-five CSF samples (34 on continued therapy and 31 on monotherapy) from 49 HIV-positive patients enrolled in MOST. Using enzyme-linked immunosorbent assay, we determined the CSF concentration of S100B (astrocytosis), neopterin (inflammation), total Tau (tTau), phosphorylated Tau (pTau), and amyloid-β 1–42 (Aβ), the latter three indicating neuronal damage. Controls were CSF samples of 29 HIV-negative patients with Alzheimer dementia. Results: In the CSF of monotherapy, concentrations of S100B and neopterin were significantly higher than in continued therapy (P = 0.006 and P = 0.013, respectively) and Alzheimer dementia patients (P < 0.0001 and P = 0.0005, respectively). In Alzheimer dementia, concentration of Aβ was lower than in monotherapy (P = 0.005) and continued therapy (P = 0.016) and concentrations of tTau were higher than in monotherapy (P = 0.019) and continued therapy (P = 0.001). There was no difference in pTau among the three groups. After removal of the 16 CSF with detectable viral load in the blood and/or CSF, only S100B remained significantly higher in monotherapy than in the two other groups. Conclusion: Despite full viral load-suppression in blood and CSF, antiretroviral monotherapy with lopinavir/ritonavir can raise CSF levels of S100B, suggesting astrocytic damage.

ISL1 expression is not restricted to pancreatic well-differentiated neuroendocrine neoplasms, but is also commonly found in well and poorly differentiated neuroendocrine neoplasms of extrapancreatic origin

The human insulin gene enhancer-binding protein islet-1 (ISL1) is a transcription factor involved in the differentiation of the neuroendocrine pancreatic cells. Recent studies identified ISL1 as a marker for pancreatic well-differentiated neuroendocrine neoplasms. However, little is known about ISL1 expression in pancreatic poorly differentiated and in extrapancreatic well and poorly differentiated neuroendocrine neoplasms. We studied the immunohistochemical expression of ISL1 in 124 neuroendocrine neoplasms. Among pancreatic neuroendocrine neoplasms, 12/13 with poor differentiation were negative, whereas 5/7 with good differentiation but a Ki67 >20% were positive. In extrapancreatic neuroendocrine neoplasms, strong positivity was found in Merkel cell carcinomas (25/25), pulmonary small cell neuroendocrine carcinomas (21/23), medullary thyroid carcinomas (9/9), paragangliomas/pheochromocytomas (6/6), adrenal neuroblastomas (8/8) and head and neck neuroendocrine carcinomas (4/5), whereas no or only weak staining was recorded in pulmonary carcinoids (3/15), olfactory neuroblastomas (1/4) and basaloid head and neck squamous cell carcinomas (0/15). ISL1 stained the neuroendocrine carcinoma component of 5/8 composite carcinomas and also normal neuroendocrine cells in the thyroid, adrenal medulla, stomach and colorectum. Poorly differentiated neuroendocrine neoplasms, regardless of their ISL1 expression, were usually TP53 positive. Our results show the almost ubiquitous expression of ISL1 in extrapancreatic poorly differentiated neuroendocrine neoplasms and neuroblastic malignancies and its common loss in pancreatic poorly differentiated neuroendocrine neoplasms. These findings modify the role of ISL1 as a marker for pancreatic neuroendocrine neoplasms and suggest that ISL1 has a broader involvement in differentiation and growth of neuroendocrine neoplasms than has so far been assumed.

Glucagon-like peptide-1 receptor imaging for the localisation of insulinomas: a prospective multicentre imaging study

BACKGROUND Small benign insulinomas are hard to localise, leading to difficulties in planning of surgical interventions. We aimed to prospectively assess the insulinoma detection rate of single-photon emission CT in combination with CT (SPECT/CT) with a glucagon-like peptide-1 receptor avid radiotracer, and compare detection rates with conventional CT/MRI techniques. METHODS In our prospective imaging study, we enrolled adults aged 25-81 years at centres in Germany, Switzerland, and the UK. Eligible patients had proven clinical and biochemical endogenous hyperinsulinaemic hypoglycaemia and no evidence for metastatic disease on conventional imaging. CT/MRI imaging was done at referring centres according to standard protocols. At three tertiary nuclear medicine centres, we used whole body planar images and SPECT/CT of the abdomen up to 168 h after injection of (111)In-[Lys40(Ahx-DTPA-(111)In)NH2]-exendin-4 ((111)In-DTPA-exendin-4) to identify insulinomas. Consenting patients underwent surgery and imaging findings were confirmed histologically. FINDINGS Between Oct 1, 2008, and Dec 31, 2011, we recruited 30 patients. All patients underwent (111)In-DTPA-exendin-4 imaging, 25 patients underwent surgery (with histological analysis), and 27 patients were assessed with CT/MRI. (111)In-DTPA-exendin-4 SPECT/CT correctly detected 19 insulinomas and four additional positive lesions (two islet-cell hyperplasia and two uncharacterised lesions) resulting in a positive predictive value of 83% (95% CI 62-94). One true negative (islet-cell hyperplasia) and one false negative (malignant insulinoma) result was identified in separate patients by (111)In-DTPA-exendin-4 SPECT/CT. Seven patients (23%) were referred to surgery on the basis of (111)In-DTPA-exendin-4 imaging alone. For 23 assessable patients, (111)In-DTPA-exendin-4 SPECT/CT had a higher sensitivity (95% [95% CI 74-100]) than did CT/MRI (47% [27-68]; p=0·011). INTERPRETATION (111)In-DTPA-exendin-4 SPECT/CT could provide a good second-line imaging strategy for patients with negative results on initial imaging with CT/MRI. FUNDING Oncosuisse, the Swiss National Science Foundation, and UK Department of Health.

Caspase-3 mediates hippocampal apoptosis in pneumococcal meningitis

Bacterial meningitis causes neuronal apoptosis in the hippocampal dentate gyrus, which is associated with learning and memory impairments after cured disease. The execution of the apoptotic program involves pathways that converge on activation of caspase-3, which is required for morphological changes associated with apoptosis. Here, the time course and the role of caspase-3 in neuronal apoptosis was assessed in an infant rat model of pneumococcal meningitis. During clinically asymptotic meningitis (0-12 h after infection), only minor apoptotic damage to the dentate gyrus was observed, while the acute phase (18-24 h) was characterized by a massive increase of apoptotic cells, which peaked at 36 h. In the subacute phase of the disease (36-72 h), the number of apoptotic cells decreased to control levels. Enzymatic caspase-3 activity was significantly increased in hippocampal tissue of infected animals compared to controls at 22 h. The activated enzyme was localized to immature cells of the dentate gyrus, and in vivo activity was evidenced by cleavage of the amyloid-beta precursor protein. Intracisternal administration of the caspase-3-specific inhibitor Ac-DEVD-CHO significantly reduced apoptosis in the hippocampal dentate gyrus. In contrast to a study where the decrease of hippocampal apoptosis after administration of a pan-caspase inhibitor was due to downmodulation of the inflammatory response, our data demonstrate that specific inhibition of caspase-3 did not affect inflammation assessed by TNF-alpha and IL-1beta concentrations in the cerebrospinal fluid space. Taken together, the present results identify caspase-3 as a key effector of neuronal apoptosis in pneumococcal meningitis.

Sex Differences in the Gut Microbiome Drive Hormone-Dependent Regulation of Autoimmunity

Microbial exposures and sex hormones exert potent effects on autoimmune diseases, many of which are more prevalent in women. We demonstrate that early-life microbial exposures determine sex hormone levels and modify progression to autoimmunity in the nonobese diabetic (NOD) mouse model of type 1 diabetes (T1D). Colonization by commensal microbes elevated serum testosterone and protected NOD males from T1D. Transfer of gut microbiota from adult males to immature females altered the recipient's microbiota, resulting in elevated testosterone and metabolomic changes, reduced islet inflammation and autoantibody production, and robust T1D protection. These effects were dependent on androgen receptor activity. Thus, the commensal microbial community alters sex hormone levels and regulates autoimmune disease fate in individuals with high genetic risk.

Latrepirdine improves cognition and arrests progression of neuropathology in an Alzheimer's mouse model

Latrepirdine (Dimebon) is a pro-neurogenic, antihistaminic compound that has yielded mixed results in clinical trials of mild to moderate Alzheimer's disease, with a dramatically positive outcome in a Russian clinical trial that was unconfirmed in a replication trial in the United States. We sought to determine whether latrepirdine (LAT)-stimulated amyloid precursor protein (APP) catabolism is at least partially attributable to regulation of macroautophagy, a highly conserved protein catabolism pathway that is known to be impaired in brains of patients with Alzheimer's disease (AD). We utilized several mammalian cellular models to determine whether LAT regulates mammalian target of rapamycin (mTOR) and Atg5-dependent autophagy. Male TgCRND8 mice were chronically administered LAT prior to behavior analysis in the cued and contextual fear conditioning paradigm, as well as immunohistological and biochemical analysis of AD-related neuropathology. Treatment of cultured mammalian cells with LAT led to enhanced mTOR- and Atg5-dependent autophagy. Latrepirdine treatment of TgCRND8 transgenic mice was associated with improved learning behavior and with a reduction in accumulation of Aβ42 and α-synuclein. We conclude that LAT possesses pro-autophagic properties in addition to the previously reported pro-neurogenic properties, both of which are potentially relevant to the treatment and/or prevention of neurodegenerative diseases. We suggest that elucidation of the molecular mechanism(s) underlying LAT effects on neurogenesis, autophagy and behavior might warranty the further study of LAT as a potentially viable lead compound that might yield more consistent clinical benefit following the optimization of its pro-neurogenic, pro-autophagic and/or pro-cognitive activities.

Systemic light-chain amyloidosis revealed by progressive nail involvement, diffuse alopecia and sicca syndrome: report of an unusual case with a review of the literature.

Immunoglobulin light-chain (AL) amyloidosis is a form of systemic amyloidosis in which the fibrils are derived from monoclonal light chains. We report a case of a 66-year-old woman presenting with nail changes, parchment-like hand changes, progressive alopecia and sicca syndrome. Histopathological studies of biopsy specimens of the scalp, the nail, minor labial salivary glands and abdominal skin revealed deposits of AL κ-type amyloid. Urine protein electrophoresis exhibited a weak band of κ-type light chains. Based on this striking case, we here review the characteristic nail and hair manifestations associated with systemic amyloidosis. Knowledge of these signs is important for an early diagnosis of systemic amyloidosis, identification of the underlying disease and patient management.

Metabolic adaptations and changes of the mammary immune response during beta-hydroxybutyrate administration

Elevation of ketone bodies occurs frequently after parturition during negative energy balance in high yielding dairy cows. Previous studies illustrated that hyperketonemia interferes with metabolism and it is assumed that it impairs the immune response. However, a causative effect of ketone bodies could not be shown in vivo before, because spontaneous hyperketonemia comes usually along with high NEFA and low glucose concentrations. The objective was to study effects of beta-hydroxybutyrate (BHBA) infusion and an additional intramammary lipopolysaccharide (LPS) challenge on metabolism and immune response in dairy cows. Thirteen dairy cows received intravenously either a BHBA infusion (group BHBA, n=5) to induce hyperketonemia (1.7 mmol/L), or an infusion with a 0.9 % saline solution (Control, n=8) for 56 h. Infusions started at 0900 on day 1 and continue up to 1700 two days later. Two udder quarters were challenged with 200 μg Escherichia coli-LPS 48 h after the start of infusion. Blood samples were taken one week and 2 h before the start of infusions as reference samples and hourly during the infusion. Liver and mammary gland biopsies were taken one week before the start of the infusion, 48 h after the start of the infusion, and mammary tissues was additionally taken 8 h after LPS challenge (56 h after the start of infusions). Rectal temperature (RT) and somatic cell count (SCC) was measured before and 48 h after the start of infusions and hourly during LPS challenge. Blood samples were analyzed for plasma glucose, BHBA, NEFA, triglyceride, urea, insulin, glucagon, and cortisol concentration. The mRNA abundance of factors related to potential adaptations of metabolism and immune system was measured in liver and mammary tissue biopsies. Differences between blood constituents, RT, SCC, and mRNA abundance before and 48 h after the start of infusions, and differences between mRNA abundance before and after LPS challenges were tested for significance by GLM of SAS procedure with treatment as fixed effect. Area under the curve was calculated for blood variables during 48 h BHBA infusion and during the LPS challenge, and additionally for RT and SCC during the LPS challenge. Most surprisingly, both plasma glucose and glucagon concentration decreased during the 48 h of BHBA infusion (P<0.05). During the 48 h of BHBA infusion, serum amyloid A mRNA abundance in mammary gland was increased (P<0.01), and haptoglobin (Hp) mRNA abundance tended to increase in cows treated with BHBA compared to control group (P= 0.07). RT, SCC, and candidate genes related to immune response in the liver were not affected by BHBA infusion. However, during LPS challenge the expected increase of both plasma glucose and glucagon concentration was much less pronounced in the animals treated with BHBA (P<0.05) and also SCC increased much less pronounced in the animals infused with BHBA (P<0.05) than in the controls. An increased BHBA infusion rate to maintain plasma BHBA constant could not fully compensate for the decreased plasma BHBA during the LPS challenge which indicates that BHBA is used as an energy source during the immune response. In addition, BHBA infused animals showed a more pronounced increase of mRNA abundance of IL-8, IL-10, and citrate synthase in the mammary tissue of LPS challenged quarters (P<0.05) than control animals. Results demonstrate that infusion of BHBA affects metabolism through decreased plasma glucose concentration which is likely related to a decreased release of glucagon during hyperketonemia and during additional inflammation. It also affects the systemic and mammary immune response which may reflect the increased susceptibility for mastitis during spontaneous hyperketonemia. The obviously reduced gluconeogenesis in response to BHBA infusion may be a mechanism to stimulated the use of BHBA as an energy source instead of glucose, and/or to save oxaloacetate for the citric acid cycle instead of gluconeogenesis and as a consequence to reduce ketogenesis.

Hyperplasia to neoplasia sequence of duodenal and pancreatic neuroendocrine diseases and pseudohyperplasia of the PP-cells in the pancreas.

Hyperplastic changes of the neuroendocrine cell system may have the potential to evolve into neoplastic diseases. This is particularly the case in the setting of genetically determined and hereditary neuroendocrine tumor syndromes such as MEN1. The review discusses the MEN1-associated hyperplasia-neoplasia sequence in the development of gastrinomas in the duodenum and glucagon-producing tumors in the pancreas. It also presents other newly described diseases (e.g., glucagon cell adenomatosis and insulinomatosis) in which the tumors are (or most likely) also preceded by islet cell hyperplasia. Finally, the pseudohyperplasia of PP-rich islets in the pancreatic head is defined as a physiologic condition clearly differing from other hyperplastic-neoplastic neuroendocrine diseases.

Induced hyperketonemia affects the mammary immune response during lipopolysaccharide challenge in dairy cows

Metabolic adaptations during negative energy and nutrient balance in dairy cows are thought to cause impaired immune function and hence increased risk of infectious diseases, including mastitis. Characteristic adaptations mostly occurring in early lactation are an elevation of plasma ketone bodies and free fatty acids (nonesterified fatty acids, NEFA) and diminished glucose concentration. The aim of this study was to investigate effects of elevated plasma β-hydroxybutyrate (BHBA) at simultaneously even or positive energy balance and thus normal plasma NEFA and glucose on factors related to the immune system in liver and mammary gland of dairy cows. In addition, we investigated the effect of elevated plasma BHBA and intramammary lipopolysaccharide (LPS) challenge on the mammary immune response. Thirteen dairy cows were infused either with BHBA (HyperB, n=5) to induce hyperketonemia (1.7 mmol/L) or with a 0.9% saline solution (NaCl, n=8) for 56 h. Two udder quarters were injected with 200 μg of LPS after 48 h of infusion. Rectal temperature (RT) and somatic cell counts (SCC) were measured before, at 48 h after the start of infusions, and hourly during the LPS challenge. The mRNA abundance of factors related to the immune system was measured in hepatic and mammary tissue biopsies 1 wk before and 48 h after the start of the infusion, and additionally in mammary tissue at 56 h of infusion (8h after LPS administration). At 48 h of infusion in HyperB, the mRNA abundance of serum amyloid A (SAA) in the mammary gland was increased and that of haptoglobin (Hp) tended to be increased. Rectal temperature, SCC, and mRNA abundance of candidate genes in the liver were not affected by the BHBA infusion until 48 h. During the following LPS challenge, RT and SCC increased in both groups. However, SCC increased less in HyperB than in NaCl. Quarters infused with LPS showed a more pronounced increase of mRNA abundance of IL-8 and IL-10 in HyperB than in NaCl. The results demonstrate that an increase of plasma BHBA upregulates acute phase proteins in the mammary gland. In response to intramammary LPS challenge, elevated BHBA diminishes the influx of leukocytes from blood into milk, perhaps by via modified cytokine synthesis. Results indicate that increased ketone body plasma concentrations may play a crucial role in the higher mastitis susceptibility in early lactation.

An ambulance for retinol.

During inflammation, serum amyloid A proteins transport retinol to infected tissues.

Toxicity of eosinophil MBP is repressed by intracellular crystallization and promoted by extracellular aggregation.

Eosinophils are white blood cells that function in innate immunity and participate in the pathogenesis of various inflammatory and neoplastic disorders. Their secretory granules contain four cytotoxic proteins, including the eosinophil major basic protein (MBP-1). How MBP-1 toxicity is controlled within the eosinophil itself and activated upon extracellular release is unknown. Here we show how intragranular MBP-1 nanocrystals restrain toxicity, enabling its safe storage, and characterize them with an X-ray-free electron laser. Following eosinophil activation, MBP-1 toxicity is triggered by granule acidification, followed by extracellular aggregation, which mediates the damage to pathogens and host cells. Larger non-toxic amyloid plaques are also present in tissues of eosinophilic patients in a feedback mechanism that likely limits tissue damage under pathological conditions of MBP-1 oversecretion. Our results suggest that MBP-1 aggregation is important for innate immunity and immunopathology mediated by eosinophils and clarify how its polymorphic self-association pathways regulate toxicity intra- and extracellularly.

Sleep-Wake Cycle Dysfunction in the TgCRND8 Mouse Model of Alzheimer's Disease: From Early to Advanced Pathological Stages.

In addition to cognitive decline, individuals affected by Alzheimer's disease (AD) can experience important neuropsychiatric symptoms including sleep disturbances. We characterized the sleep-wake cycle in the TgCRND8 mouse model of AD, which overexpresses a mutant human form of amyloid precursor protein resulting in high levels of β-amyloid and plaque formation by 3 months of age. Polysomnographic recordings in freely-moving mice were conducted to study sleep-wake cycle architecture at 3, 7 and 11 months of age and corresponding levels of β-amyloid in brain regions regulating sleep-wake states were measured. At all ages, TgCRND8 mice showed increased wakefulness and reduced non-rapid eye movement (NREM) sleep during the resting and active phases. Increased wakefulness in TgCRND8 mice was accompanied by a shift in the waking power spectrum towards fast frequency oscillations in the beta (14-20 Hz) and low gamma range (20-50 Hz). Given the phenotype of hyperarousal observed in TgCRND8 mice, the role of noradrenergic transmission in the promotion of arousal, and previous work reporting an early disruption of the noradrenergic system in TgCRND8, we tested the effects of the alpha-1-adrenoreceptor antagonist, prazosin, on sleep-wake patterns in TgCRND8 and non-transgenic (NTg) mice. We found that a lower dose (2 mg/kg) of prazosin increased NREM sleep in NTg but not in TgCRND8 mice, whereas a higher dose (5 mg/kg) increased NREM sleep in both genotypes, suggesting altered sensitivity to noradrenergic blockade in TgCRND8 mice. Collectively our results demonstrate that amyloidosis in TgCRND8 mice is associated with sleep-wake cycle dysfunction, characterized by hyperarousal, validating this model as a tool towards understanding the relationship between β-amyloid overproduction and disrupted sleep-wake patterns in AD.

The immune response of bovine mammary epithelial cells to live or heat-inactivated Mycoplasma bovis

Mycoplasma bovis is an emerging bacterial agent causing bovine mastitis. Although these cell wall-free bacteria lack classical virulence factors, they are able to activate the immune system of the host. However, effects on the bovine mammary immune system are not yet well characterized and detailed knowledge would improve the prevention and therapy of mycoplasmal mastitis. The aim of this study was to investigate the immunogenic effects of M. bovis on the mammary gland in an established primary bovine mammary epithelial cell (bMEC) culture system. Primary bMEC of four different cows were challenged with live and heat-inactivated M. bovis strain JF4278 isolated from acute bovine mastitis, as well as with the type strain PG45. The immune response was evaluated 6 and 24h after mycoplasmal challenge by measuring the relative mRNA expression of selected immune factors by quantitative PCR. M. bovis triggered an immune response in bMEC, reflected by the upregulation of tumor necrosis factor-α, interleukin(IL)-1β, IL-6, IL-8, lactoferrin, Toll-like receptor-2, RANTES, and serum amyloid A mRNA. Interestingly, this cellular reaction was only observed in response to live, but not to heat-inactivated M. bovis, in contrast to other bacterial pathogens of mastitis such as Staphylococcus aureus. This study provides evidence that bMEC exhibit a strong inflammatory reaction in response to live M. bovis. The lack of a cellular response to heat-inactivated M. bovis supports the current hypothesis that mycoplasmas activate the immune system through secreted secondary metabolites.