Replacement of Fhit in cancer cells suppresses tumorigenicity

The candidate tumor suppressor gene, FHIT, encompasses the common human chromosomal fragile site at 3p14.2, the hereditary renal cancer translocation breakpoint, and cancer cell homozygous deletions. Fhit hydrolyzes dinucleotide 5′,5-P¹,P³-triphosphate in vitro and mutation of a central histidine abolishes hydrolase activity. To study Fhit function, wild-type and mutant FHIT genes were transfected into cancer cell lines that lacked endogenous Fhit. No consistent effect of exogenous Fhit on growth in culture was observed, but Fhit and hydrolase “dead” Fhit mutant proteins suppressed tumorigenicity in nude mice, indicating that 5′,5-P¹,P³-triphosphate hydrolysis is not required for tumor suppression.     

Serum substance P: an indicator of disease activity and subclinical inflammation in rheumatoid arthritis

The aim of the is study is to examine the role of serum substance P (SP) levels as a simple biomarker for rheumatoid arthritis (RA) disease activity, its correlation with other markers of disease activity, and with selected clinical parameters. The study comprised 90 RA patients and 24 healthy controls. RA activity was assessed by means of the disease activity 28-C-reactive protein (DAS28-CRP) index and ultrasound power Doppler (USPD) by the German ultrasound score based on seven joints. SP serum values were obtained by means of an ELISA commercial kit. Statistics were achieved by the Student’s t test and Spearman correlation analysis with Bonferroni correction. As a group, RA patients had significantly increased levels of SP compared with healthy controls (p?<?0.0001). SP levels correlated with DAS28-CRP (r =?0.5050, p?<?0.0001), number of tender joints (NTJ, r =?0.4668, p?<?0.0001), number of swollen joints (NSJ, r?=?0.4439, p?<?0.0001), visual analogue scale (VAS, r?=?0.5131, p?<?0.0001). However, SP did not correlate with CRP levels (r?=?0.0468, p?=?0.6613), nor with the USPD (r?=?0.1740, p?=?0.1009). Elevated serum SP is a common feature of RA patients, which also appears to correlate with clinical measurements of disease activity and with subjective clinical data (NTJ and VAS). Thus, although SP is higher in RA patients with high disease activity, it also detects subtle RA disease activity even in patients in apparent remission, which suggests its usefulness for therapeutic decisions.     

Cannabidiol, unlike synthetic cannabinoids, triggers activation of RBL-2H3 mast cells

Cannabidiol (CBD), a prominent psychoinactive component of cannabis with negligible affinity for known cannabinoid receptors, exerts numerous pharmacological actions, including anti-inflammatory and immunosuppressive effects, the underlying mechanisms of which remain unclear. In the current study, we questioned whether CBD modulates activation of mast cells, key players in inflammation. By using the rat basophilic leukemia mast cell line (RBL-2H3), we demonstrate that CBD (3-10 muM) augments beta-hexosaminidase release, a marker of cell activation, from antigen-stimulated and unstimulated cells via a mechanism, which is not mediated by G(i)/G(o) protein-coupled receptors but rather is associated with a robust rise in intracellular calcium ([Ca(2+)](i)) levels sensitive to clotrimazole and nitrendipine (10-30 muM). This action, although mimicked by Delta(9)-tetrahydrocannabinol (THC), is opposite to that inhibitory, exerted by the synthetic cannabinoids WIN 55,212-2 and CP 55,940. Moreover, the vanilloid capsaicin, a full agonist of transient receptor potential channel VR1, did not affect [Ca(2+)](i)levels in the RBL-2H3 cells, thus excluding the involvement of this receptor in the CBD-mediated effects. Together, these results support existence of yet-to-be identified sites of interaction, i.e., receptors and/or ion channels associated with Ca(2+) influx of natural cannabinoids such as CBD and THC, the identification of which has the potential to provide for novel strategies and agents of therapeutic interest.     

Effects of low dietary magnesium intake on development of hypertension in stroke-prone spontaneously hypertensive rats: role of reactive oxygen species

OBJECTIVES: To investigate whether low dietary Mg2+ intake influences the development of hypertension in stroke-prone spontaneously hypertensive rats (spSHRs) and whether these effects are associated with vascular functional and structural changes, and to assess the role of reactive oxygen species and the activation of vascular mitogen-activated protein (MAP) kinases in these processes. METHODS: Six-week-old male spSHRs (n = 18) were divided into three groups: control (normal chow, 0.21% Mg2+ ), low Mg2+ group (Mg2+ -free diet), and high Mg2+ group (Mg2+ -rich diet, 0.75%). Systolic blood pressure (SBP) was assessed weekly for 16 weeks. In a second series of experiments, 6-week-old spSHRs (n = 18) were divided into three groups and studied weekly for 7 weeks: control group, low Mg2+ group, and low Mg2+ group receiving the superoxide dismutase mimetic, tempol (1 mmol/l). RESULTS: The low Mg2+ diet caused an initial decrease in SBP followed, 5 weeks later, by an exacerbated development of hypertension. This was associated with a transient reduction in the plasma concentrations of substances associated with the thiobarbituric acid reaction (markers of oxidative stress), which increased rapidly 2 weeks later. In the low Mg2+ group, acetylcholine-induced vasodilatation was decreased compared with that in controls ( P<0.05). The media : lumen ratio was greater in rats receiving a low Mg2+ diet than in those fed a high Mg2+ diet ( P<0.05). Mg2+ depletion was associated with increased vascular superoxide anion compared with that in Mg2+ -supplemented rats (1.2 0.24 compared with 0.65 0.1 nmol/min per mg). Phosphorylation of MAP kinases was increased two- to threefold in Mg2+ -deficient rats. Tempol prevented the progression of hypertension and normalized the vascular changes in rats fed a low Mg2+ diet. CONCLUSIONS: Chronic Mg2+ deficiency leads to development of severe hypertension, endothelial dysfunction and vascular remodelling. These processes are associated with oxidative stress and upregulation of redox-dependent MAP kinases. Tempol normalized vascular changes and attenuated the development of hypertension. Our findings suggest that reactive oxygen species play an important part in vascular processes that are associated with progression of hypertension in Mg2+ -deficient spSHRs.     

High frequency of mutant thiopurine S-methyltransferase genotypes in Mexican patients with systemic lupus erythematosus and rheumatoid arthritis

Systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA) are treated with immunosuppressive purine analogs, 6-mercaptopurine/6-thioguanine/azathiopurine, which are inactivated by thiopurine S-methyltransferase (TPMT). Non-synonymous polymorphisms in TPMT are associated with increased risk of adverse effects in patients treated with thiopurines. This study aimed to determine the frequency of the most common mutant TPMT alleles in Mexican patients with SLE (a prototype autoimmune disease) and RA (one of the most common autoimmune diseases in Mexico). Five hundred fifty-three consecutive patients from Central Mexico with SLE (178) and RA (375) were included. Subjects were genotyped to identify TPMT*2 (rs1800462), TPMT*3A (rs1800460 and rs1142345), TPMT*3B (rs1800460), and TPMT*3C (rs1142345) mutant alleles. DNA samples were assayed with the 5′ exonuclease technique and TaqMan probes. Mutant alleles were detected in 6.2 and 5.2% of SLE and RA cases, respectively. Of note, 12.4% of SLE cases and 10.1% of RA cases carried mutant genotypes. Among those, the null genotype (TPMT*2/*3A, 0.3%) and the TPMT*3B (0.5%) and TPMT*3C (1.0%) alleles were found in RA, but not SLE cases. Mexican SLE cases displayed the highest frequency of mutant TPMT genotypes worldwide. TPMT genotyping should be performed for Mexican patients with SLE and RA before prescribing purine analogs.     

Assessment of the psychometric properties of the Detection of Emotional Distress Scale in cancer patients

Objective

To evaluate and alleviate the emotional distress suffered by advanced cancer patients, simple screening methods that can be easily used by health staff and easily understood by patients are required. The objective of this multicenter study was to analyze the psychometric properties and clinical utility of the Detection of Emotional Distress (DED) scale in advanced cancer patients attending a palliative care unit.

Methods

The DED scale was administered to 105 advanced cancer patients attended in five palliative care units in Catalonia (Spain).

Results

A total of 58.3% of the patients had moderate to severe emotional distress, a result similar to those of other scales such as the emotional thermometer. Statistical analysis of ROC curves suggested that the cutoff for the detection of emotional distress by the DED scale was equivalent to a score of ≥ 9 points, with a sensitivity and specificity above 75%.

Conclusions

The DED scale is useful and easy to use in the identification of emotional distress in advanced cancer patients attended in palliative care units. This scale could also be applied in other patients and health care fields, such as patients with chronic diseases, home care, and primary care.