Antibody to tumor necrosis factor (TNF) reduces endotoxin fever

Summary Antibody to tumor necrosis factor (TNF), injected intravenously, reduced endotoxin fever in the rabbit. The fever-reducing effect was apparent in the latter half of the febrile response.This work was supported by a Grants-in-Aid from the Ministry of Education, Science and Culture of Japan (Grant No. 62480112).     

Antibody to tumor necrosis factor (TNF) reduces endotoxin fever

Antibody to tumor necrosis factor (TNF), injected intravenously, reduced endotoxin fever in the rabbit. The fever-reducing effect was apparent in the latter half of the febrile response.     

The role of the insulin-like growth factor (IGF) axis in osteogenic and odontogenic differentiation

The insulin-like growth factor (IGF) axis is a multicomponent molecular network which has important biological functions in the development and maintenance of differentiated tissue function(s). One of the most important functions of the IGF axis is the control of skeletal tissue metabolism by the finely tuned regulation of the process of osteogenesis. To achieve this, the IGF axis controls the activity of several cell types—osteoprogenitor cells, osteoblasts, osteocytes and osteoclasts to achieve the co-ordinated development of appropriate hard tissue structure and associated matrix deposition. In addition, there is an increasing awareness that the IGF axis also plays a role in the process of odontogenesis (tooth formation). In this review, we highlight some of the key findings in both of these areas. A further understanding of the role of the IGF axis in hard tissue biology may contribute to tissue regeneration strategies in cases of skeletal tissue trauma.     

Hageman factor (factor XII) activity in synovial fluid of rheumatoid arthritis patients and its possible pathogenic significance

Résumé Nous avons constaté que l'activité spécifique du facteur de Hageman dans le fluide synovial de malades atteints de polyarthrite chronique évolutive est beaucoup plus elevée que celle d'autres agents de coagulation. L'activité du facteur de Hageman a été isolée du fluide synovial et de la suspension de leucocytes par adsorption sur kaolin et élution au pH alcalin.     

Activation of protease-activated receptor (PAR) 1 by frog trefoil factor (TFF) 2 and PAR4 by human TFF2

Trefoil factors (TFFs) promote epithelial cell migration to reseal superficial wounds after mucosal injury, but their receptors and the molecular mechanisms underlying this process are poorly understood. In this study, we showed that frog TFF2 activates protease-activated receptor (PAR) 1 to induce human platelet aggregation. Based on this result, we further tested the involvement of PARs in human TFF2 (hTFF2)-promoted mucosal healing. hTFF2-stimulated migration of epithelial HT-29 cells was largely inhibited by PAR4 depletion with small interfering RNAs but not by PAR1 or PAR2 depletion. The PAR4-negative epithelial cell lines AGS and LoVo were highly responsive to hTFF2 as assessed by phosphorylation of ERK1/2 and cell migration upon PAR4 expression. Our findings suggest that hTFF2 promotes cell migration via PAR4. These findings will be helpful in further investigations into the functions and molecular mechanisms of TFFs and PARs in physiology and disease.     

Schistosoma mansoni: A chemoattractive factor released by males and its receptor in females

Chemoattraction between developing (23- to 28-day-old) and adult (10- to 12-week-old)Schistosoma mansoni males and females has been described previously. We report here on in vitro attraction of mature worms to released products of worms of the opposite sex. In the absence of a stimulus worms migrated randomly and did not show any preference in their orientation. Males were not significantly attracted to released products of females. Females exhibited greatest attraction to released products of males, and some attraction to the lipid fraction of released products of males. The aqueous fraction of male-released products slightly repelled females. Prior exposure to released products of males rendered females unresponsive to subsequent exposure, suggesting receptor saturation. These findings have important potential implicatons for the control of schistosomiasis by intercepting attraction and mating between males and females.     

Schistosoma mansoni: a chemoattractive factor released by males and its receptor in females

Chemoattraction between developing (23- to 28-day-old) and adult (10- to 12-week-old) Schistosoma mansoni males and females has been described previously. We report here on in vitro attraction of mature worms to released products of worms of the opposite sex. In the absence of a stimulus worms migrated randomly and did not show any preference in their orientation. Males were not significantly attracted to released products of females. Females exhibited greatest attraction to released products of males, and some attraction to the lipid fraction of released products of males. The aqueous fraction of male-released products slightly repelled females. Prior exposure to released products of males rendered females unresponsive to subsequent exposure, suggesting receptor saturation. These findings have important potential implications for the control of schistosomiasis by intercepting attraction and mating between males and females.     

SNX3-dependent regulation of epidermal growth factor receptor (EGFR) trafficking and degradation by aspirin in epidermoid carcinoma (A-431) cells

Since being introduced globally as aspirin in 1899, acetylsalicylic acid has been widely used as an analgesic, anti-inflammation, anti-pyretic, and anti-thrombotic drug for years. Aspirin had been reported to down-regulate surface expression of CD40, CD80, CD86, and MHCII in myeloid dendritic cells (DC), which played essential roles in regulating the immune system. We hypothesized that the down-regulation of these surface membrane proteins is partly due to the ability of aspirin in regulating trafficking/sorting of endocytosed surface membrane proteins. By using an established epidermoid carcinoma cell line (A-431), which overexpresses the epidermal growth factor receptor (EGFR) and transferrin receptor (TfnR), we show that aspirin (1) reduces cell surface expression of EGFR and (2) accumulates endocytosed-EGFR and -TfnR in the early/sorting endosome (ESE). Further elucidation of the mechanism suggests that aspirin enhances recruitment of SNX3 and SNX5 to membranes and consistently, both SNX3 and SNX5 play essential roles in the aspirin-mediated accumulation of endocytosed-TfnR at the ESE. This study sheds light on how aspirin may down-regulate surface expression of EGFR by inhibiting/delaying the exit of endocytosed-EGFR from the ESE and recycling of endocytosed-EGFR back to the cell surface.     

Adsorption of hageman factor (factor XII) on collagen

Résumé Nous avons trouvé que le facteur Hageman (factor XII), contenu dans le plasma humain citraté, pauvre en plaquettes, est adsorbé presque sélectivement par le collagène. Il est également possible d'éluer ce facteur au pH alcalin.     

Solubility of the hypothalamic hormones TSH-releasing factor (TRF) and LH-releasing factor (LRF) in organic and alcoholic solvents

Résumé L'hormone hypothalamique TRF (TSH-releasing factor) est soluble dans l'alcool méthylique à 90%, partiellement soluble dans l'alcool méthylique absolu ou le chloroforme; TRF n'est pas soluble dans la pyridine. Le chlorure de méthylène (dichlorométhane) n'extrait pas le TRF d'une solution aqueuse (préparation hautement purifiée, 15000 U/mg). L'hormone hypothalamique LRF (LH-releasing factor) n'est pas soluble dans le chloroforme mais est soluble dans l'alcool méthylique absolu ou à 90%.

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Supported by U.S.P.H.S. research grants No. AM 08290.03, No. HD 02577.01, training grant No. GM 956.04; also No. FR 00254 to Common Research Computer Facility, Texas Medical Center.     

Characterization of the third component of pig complement and its utilization in a C3b receptor study

Summary The third component of the pig complement system (C3) was isolated in hemolytically active form and characterized. The C3 component is a -globulin with the molecular weight of 191,000 and is composed of 2 non-identical polypeptide chains of M_t 112,000 and 74,000. The isolated C3 can be used for the detection of the C3b receptor on the membranes of heterologous peritoneal macrophages.     

Characterization of the 5-HT1A receptor of the honeybee (Apis mellifera) and involvement of serotonin in phototactic behavior

Serotonin plays a key role in modulating various physiological and behavioral processes in both protostomes and deuterostomes. The vast majority of serotonin receptors belong to the superfamily of G-protein-coupled receptors. We report the cloning of a cDNA from the honeybee (Am5-ht1A) sharing high similarity with members of the 5-HT₁ receptor class. Activation of Am5-HT_1A by serotonin inhibited the production of cAMP in a dose-dependent manner (EC₅₀ = 16.9 nM). Am5-HT_1A was highly expressed in brain regions known to be involved in visual information processing. Using in vivo pharmacology, we could demonstrate that Am5-HT_1A receptor ligands had a strong impact on the phototactic behavior of individual bees. The data presented here mark the first comprehensive study—from gene to behavior—of a 5-HT_1A receptor in the honeybee, paving the way for the eventual elucidation of additional roles of this receptor subtype in the physiology and behavior of this social insect.