Postsynaptic density antigens: preparation and characterization of an antiserum against postsynaptic densities

Long-term immunization of rabbits with postsynaptic densities (PSD) from bovine brain produced an antiserum specific for PSD as judged by binding to subcellular fractions and immunohistochemical location at the light and electron microscope levels. (a) The major antigens of bovine PSD preparations were three polypeptides of molecular weight 95,000 (PSD-95), 82,000 (PSD-82), and 72,000 (PSD-72), respectively. Antigen PSD-95, also present in mouse and rat PSDs was virtually absent from cytoplasm, myelin, mitochondria, and microsomes from rodent or bovine brain. Antigens PSD-82 and PSD-72 were present in all subcellular fractions from bovine brain, especially in mitochondria, but were almost absent from rodent brain. The antiserum also contained low-affinity antibodies against tubulin. (b)Immunohistochemical studies were performed in mouse and rat brain, where antigen PSD-95 accounted for 90 percent of the antiserum binding after adsorption with purified brain tubulin. At the light microscope level, antibody binding was observed only in those regions of the brain where synapses are known to be present. No reaction was observed in myelinated tracts, in the neuronal cytoplasm, or in nonneuronal cells. Strong reactivity was observed in the molecular layer of the dentate gyrus, stratum oriens and stratum radiatum of the hippocampus, and the molecular layer of the cerebellum. Experimental lesions, such as ablation of the rat entorhinal cortex or intraventricular injection of kainic acid, which led to a major loss of PSD in well- defined areas of the hippocampal formation, caused a correlative decrease in immunoreactivity in these areas. Abnormal patterns of immunohistochemical staining correlated with abnormal synaptic patterns in the cerebella of reeler and staggerer mouse mutants. (c) At the electron microscopic level, immunoreactivity was detectable only in PSD. The antibody did not bind to myelin, mitochondria or plasma membranes. (d) The results indicate that antigen PSD-95 is located predominantly or exclusively in PSD and can be used as a marker during subcellular fractionation. Other potential uses include the study of synaptogenesis, and the detection of changes in synapse number after experimental perturbations of the nervous system.     

Dermatological conditions during TNF-α-blocking therapy in patients with rheumatoid arthritis: a prospective study

Various dermatological conditions have been reported during tumor necrosis factor (TNF)-α-blocking therapy, but until now no prospective studies have been focused on this aspect. The present study was set up to investigate the number and nature of clinically important dermatological conditions during TNF-α-blocking therapy in patients with rheumatoid arthritis (RA). RA patients starting on TNF-α-blocking therapy were prospectively followed up. The numbers and natures of dermatological events giving rise to a dermatological consultation were recorded. The patients with a dermatological event were compared with a group of prospectively followed up RA control patients, naive to TNF-α-blocking therapy and matched for follow-up period. 289 RA patients started TNF-α-blocking therapy. 128 dermatological events were recorded in 72 patients (25%) during 911 patient-years of follow-up. TNF-α-blocking therapy was stopped in 19 (26%) of these 72 patients because of the dermatological event. More of the RA patients given TNF-α-blocking therapy (25%) than of the anti-TNF-α-naive patients (13%) visited a dermatologist during follow-up (P < 0.0005). Events were recorded more often during active treatment (0.16 events per patient-year) than during the period of withdrawal of TNF-α-blocking therapy (0.09 events per patient-year, P < 0.0005). The events recorded most frequently were skin infections (n = 33), eczema (n = 20), and drug-related eruptions (n = 15). Other events with a possible relation to TNF-α-blocking therapy included vasculitis, psoriasis, drug-induced systemic lupus erythematosus, dermatomyositis, and a lymphomatoid-papulosis-like eruption. This study is the first large prospective study focusing on dermatological conditions during TNF-α-blocking therapy. It shows that dermatological conditions are a significant and clinically important problem in RA patients receiving TNF-α-blocking therapy.     

Cellular Compartmentalization of Herpesvirus Antigens During Viral Replication

HEp-2 cells infected with herpes simplex virus develop five distinct immunofluorescent elements. Three (small nuclear granules, large nuclear granules, and an amorphous mass filling the nucleus) contain antigens which react with a rabbit serum prepared against boiled infected cell debris. A labeled pool of human antibody revealed antigens making up cytoplasmic granules and those responsible for a diffuse cytoplasmic fluorescence. All five immunofluorescent elements are demonstrable with a rabbit serum prepared against unheated infected cell debris. Viral antigens are segregated in the nucleus or in the cytoplasm; within the limits of detection, each antigen accumulates in one compartment only. The antigens responsible for the diffuse cytoplasmic fluorescence and for the amorphous nuclear mass are synthesized early in infection; they are formed in arginine-deprived cells and exist in a form which does not sediment on centrifugation at 79,000 x g for 2 hr. The antigens comprising the nuclear and cytoplasmic granules arise relatively late in infection; they are not formed in arginine-deprived cells, and they are readily sedimented on centrifugation at 79,000 x g for 2 hr. Heating (60 C for 2 hr) confers on one or more cytoplasmic viral antigens a new specificity; the altered antigens are demonstrable with labeled rabbit anti-boiled infected cell serum which normally does not combine with cytoplasmic antigens.     

Pentosan polysulfate promotes proliferation and chondrogenic differentiation of adult human bone marrow-derived mesenchymal precursor cells

Introduction  

This study was undertaken to determine whether the anti-osteoarthritis drug pentosan polysulfate (PPS) influenced mesenchymal precursor cell (MPC) proliferation and differentiation.     

Experimental stress in inflammatory rheumatic diseases: a review of psychophysiological stress responses

Introduction  

Stressful events are thought to contribute to the aetiology, maintenance and exacerbation of rheumatic diseases. Given the growing interest in acute stress responses and disease, this review investigates the impact of real-life experimental psychosocial, cognitive, exercise and sensory stressors on autonomic, neuroendocrine and immune function in patients with inflammatory rheumatic diseases.     

Feasibility of a liver transcriptomics approach to assess bovine treatment with the prohormone dehydroepiandrosterone (DHEA)

Background  

Within the European Union the use of growth promoting agents in animal production is prohibited. Illegal use of natural prohormones like dehydroepiandrosterone (DHEA) is hard to prove since prohormones are strongly metabolized in vivo. In the present study, we investigated the feasibility of a novel effect-based approach for monitoring abuse of DHEA. Changes in gene expression profiles were studied in livers of bull calves treated orally (PO) or intramuscularly (IM) with 1000 mg DHEA versus two control groups, using bovine 44K DNA microarrays. In contrast to controlled genomics studies, this work involved bovines purchased at the local market on three different occasions with ages ranging from 6 to 14 months, thereby reflecting the real life inter-animal variability due to differences in age, individual physiology, season and diet.     

Prevalence of methotrexate intolerance in rheumatoid arthritis and psoriatic arthritis

Introduction

The aim of this study was to determine the prevalence of gastrointestinal and behavioural symptoms occurring before (anticipatory/associative) and after methotrexate (MTX) administration, termed MTX intolerance, in rheumatoid (RA) and psoriatic arthritis (PsA).

Methods

Methotrexate Intolerance Severity Score (MISS), previously validated in juvenile idiopathic arthritis patients, was used to determine MTX intolerance prevalence in 291 RA/PsA patients. The MISS consisted of four domains: abdominal pain, nausea, vomiting and behavioural symptoms, occurring upon, prior to (anticipatory) and when thinking of MTX (associative). MTX intolerance was defined as ≥6 on the MISS with ≥1 point on anticipatory and/or associative and/or behavioural items.

Results

A total of 123 patients (42.3%) experienced at least one gastrointestinal adverse effect. The prevalence of MTX intolerance was 11%. MTX intolerance prevalence was higher in patients on parenteral (20.6%) than on oral MTX (6.2%) (p < 0.001).

Conclusion

Besides well-known gastrointestinal symptoms after MTX, RA and PsA patients experienced these symptoms also before MTX intake. RA and PsA patients on MTX should be closely monitored with the MISS for early detection of MTX intolerance, in order to intervene timely and avoid discontinuation of an effective treatment.     

Circadian phase preference in college students: relationships with psychological functioning and academics

The current study offers a comprehensive assessment of psychosocial functioning and academic performance in relation to circadian phase preference in a US sample of undergraduate college students (N?=?838), aged 17-26 (M?=?19.78, SD?=?1.89). Women had greater morning preference than men, and seniors had greater morning preference than freshmen. Circadian phase preference, fatigue, perceived stress, depression, anxiety, and substance use were assessed cross-sectionally and grade point average (GPA) was assessed prospectively. Evening phase preference was related to higher levels of fatigue, alcohol and caffeine use, and worse academic performance than morning or intermediate phase preferences.