Increased Ca++, Mg++, and Na+ + K+ ATPase activities in erythrocytes of sickle cell anemia

To determine whether diminished activity of the Ca++ extrusion pump could account for the high levels of red blood cell (RBC) Ca++ in sickle cell anemia (SS), we measured calmodulin-sensitive Ca++ ATPase activity in normal and SS RBC. Hemolysates prepared with saponin were compared, since such preparations expressed maximum ATPase activities, exceeding isolated membranes or reconstituted systems of membranes plus cytosol, SS RBC hemolysates had greater Ca++ ATPase activity than normal hemolysates; they exhibited higher Mg++ and Na+ + K+ ATPase activities as well. Assays on density (age) fractions of SS and normal red cells demonstrated that all ATPase activities were highest in low density (young) cells, and activities in SS red cells exceeded those in normals in all fractions studied. Thus, when studied under conditions that maximize enzyme activity, Ca++ ATPase activity, like Mg++ and Na+ + K+ ATPase, is actually increased in SS RBC, probably due to the young red cell population present. The elevated Ca++ levels in these cells are more likely due to an increased Ca++ leak or abnormal calcium binding than to defective extrusion by the ATPase pump.     

Modulation of murine pluripotential stem cell proliferation in vivo by lithium carbonate

The effect of administering lithium in vivo on murine pluripotential stem cell proliferation was studied. Lithium was injected i.p. at various meq/liter concentrations (0.5-5.0 meq/liter). Data was obtained establishing that lithium increased the pluripotential stem cell population from normal mice as measured by the Till and McCulloch CFUs assay. Significant increases were demonstrated in: (1) bone marrow CFUs; (2) bone marrow organ cellularity, and (3) peripheral blood WBC. Marrow CFUs increase was maximum at 4 days post-lithium injection and greatest in the 1 meq/liter group (p < 0.001). Further increases in lithium concentration, i.e., 5 meq/liter, effectively reduced CFUs levels below normal, suggesting toxicity of the drug was apparent at this dose level. We conclude lithium may modulate granulopoiesis by increasing the CFUs stem cell compartment, thereby directly channeling differentiation into the granulopoietic pathway. This increases the committed progenitor stem cell (CFUc) population and ultimately peripheral blood end-stage cells.     

Cervical Cancer Prevention on Instagram: Content and Social Interaction Analysis of Brazilian Accounts

Abstract: Objective: The aim of the present study was to analyse the content of posts on Instagram about cervical cancer. Methods: It was conducted a qualitative analysis using the 50 most popular publicly available Portuguese-language Instagram posts, containing the hashtags #cervicalcancer, #papsmear, #hpv, #papillomavirus, and #hpvvac-cine, during the Brazilian national cervical cancer prevention campaign in March 2018. Results: Posts recruited using #cervicalcancer provided 60% of posts with contents related to secondary prevention; the #papsmear provided 46% of posts with irrelevant contents; the #hpv and #papillomavirus provided 50% and 64% of posts with informative content, respectively; and the #hpvvaccine provided 58% of posts with content related to primary prevention. The posts that received the highest number of likes were those from the hashtags #hpv and #papillomavirus with 151.33 and 78.00 likes/post, respectively. The majority of posts presented less than 05 comments/post, except for the #hpv, which had 64.76 comments/post. According to the users’ profiles, the majority of the posts, regardless of the hashtag used, were made by health professionals. Conclusion: The focus of Instagram posts about cervical cancer is on secondary prevention, which can contribute to the promotion of health behaviours not directed to aspects of primary prevention of the disease.     

European legislation impedes critical care research and fails to protect patients' rights

The European Clinical Trials Directive requires an informed consent from the patient or a proxy in drug trials. Although informed consent is a valuable tool to protect patients' rights in clinical trials, this requirement largely impedes research in critical care settings, and if pursued in this context, it does not provide the patient with adequate protection. Instead of insisting on informed consent, we suggest that the focus should be shifted towards two other ethically relevant elements in human experimentation: risk assessment and selection of research subjects. When reviewing protocols in which a waiver of consent is deemed necessary, the Ethical Review Board should ensure that non-therapeutic risks are minimal, that the research is specifically designed to benefit critically ill patients, and that it cannot be conducted under circumstances where an informed consent can be obtained. If the European Directive is changed accordingly, this permits clinical trials in critical care settings, while adequate protection from risky non-therapeutic procedures is ensured and exploitation of the patient as an easily accessible research subject is prevented.     

Persistent activation of nuclear factor kappa-B signaling pathway in patients with unstable angina and elevated levels of C-reactive protein evidence for a direct proinflammatory effect of azide and lipopolysaccharide-free C-reactive protein on human monocytes via nuclear factor kappa-B activation.

OBJECTIVES: Our study investigated: 1) the contribution of nuclear factor kappa-B (NF-kappaB) signaling pathway to the enhanced inflammatory response observed in unstable angina (UA) patients with elevated levels of C-reactive protein (CRP); and 2) whether CRP may have direct proinflammatory effects via NF-kappaB activation. BACKGROUND: Unstable angina patients with elevated CRP have enhanced inflammatory response and increased risk of persistent instability, myocardial infarction, and death. METHODS: We studied 28 patients with history of UA and persistently elevated CRP (>3 mg/l) followed for 24 months and free of symptoms for at least 6 months (group 1), 14 patients with history of UA and low CRP (group 2), and 24 patients with chronic stable angina and low CRP (group 3). Peripheral blood monocytes were analyzed for spontaneous NF-kappaB activation and interleukin (IL)-6 and tumor necrosis factor (TNF)-alpha production. To assess the direct proinflammatory effects of CRP, monocytes from 8 healthy subjects were stimulated in vitro with increasing doses of CRP (5 to 10 to 25 microg/ml), lipopolysaccharide (LPS) (1 to 10 ng/ml), or both. RESULTS: Spontaneous NF-kappaB activation in vivo was demonstrated in 82% of group 1 versus 14% of group 2 and 21% of group 3 patients (p < 0.001). Interleukin-6 and TNF-alpha production was significantly correlated with the NF-kappaB activation status (r = 0.55, p < 0.001 and r = 0.53, p = 0.006, respectively). Patients with NF-kappaB activation had recurrence of acute coronary events (60% vs. 28%; p = 0.017). C-reactive protein induced a significant but modest in vitro NF-kappaB activation in human monocytes (p = 0.002). Coincubation with LPS produced a greater-than-additive response (p < 0.01 vs. CRP and LPS alone). CONCLUSIONS: Nuclear factor kappa-B activation might represent a mechanism by which CRP amplifies and perpetuates the inflammatory component of acute coronary syndromes and influences the clinical outcome.     

Point mutations in the conserved box 1 region inactivate the human granulocyte colony-stimulating factor receptor for growth signal transduction and tyrosine phosphorylation of p75c-rel

The human granulocyte colony-stimulating factor receptor (hG-CSFR) belongs to the cytokine receptor superfamily. As with other members of this family, the cytoplasmic domain of hG-CSFR lacks intrinsic tyrosine kinase activity. To identify critical regions mediating growth signal transduction by hG-CSFR, deletions or site-directed amino acid substitutions were introduced into the cytoplasmic domain of hG-CSFR, and the mutant cDNAs were transfected into the murine interleukin-3 (IL- 3)-dependent Ba/F3 and FDCP cell lines. Truncation of the carboxy- terminal end of the receptor to the membrane-proximal 53 amino acids of the cytoplasmic domain, which retained the conserved Box 1 and Box 2 sequence motifs, decreased the ability of hG-CSFR to transduce G-CSF- mediated growth signals without an associated loss in receptor binding affinity. Substitution of proline by alanine at amino acid positions 639 and 641 within Box 1 completely abolished the G-CSF-mediated growth signal. Rapid induction of tyrosine phosphorylation of several cellular proteins, including a 75-kD protein (p75) identified as c-rel, was an early event associated with transduction of proliferative signals by hG- CSFR in Ba/F3 transfectants. Mutant receptors containing Pro-to-Ala substitutions that inactivated the receptor for mitogenic activity also inactivated the receptor for tyrosine-specific phosphorylation of p75. These results show that the conserved Box 1 sequence motif (amino acids 634 to 641) is critical for mitogenesis and activation of cellular tyrosine kinases by hG-CSFR.