Platelet-activating factor primes neutrophil responses to agonists: role in promoting neutrophil-mediated endothelial damage

During inflammation polymorphonuclear cells (PMNs) are exposed to agonistic stimuli including activated complement, kallikrein, arachidonic acid metabolites, monokines, and platelet-activating factor (PAF). We report that PAF not only directly activates PMNs but in miniscule quantities (10(-12) mol/L) "primes" them as well, that is, permits PMNs to respond to subsequent stimuli that would be otherwise ineffectual. PAF priming of responses including superoxide generation, elastase release, and aggregation is time dependent and is maximal within five minutes. PAF need not be present during the subsequent exhibition of PMN agonists, but priming is inhibited by cold and is also inhibited by the PAF receptor antagonists BN 52021, L-652, and kadsurenone. An intact PAF molecule is required because lyso-PAF and methoxy-PAF do not prime PMN responses. PAF priming is associated with both enhanced expression of the adhesive glycoprotein identified by OKM- 1 antibody and an enhanced rise in intracellular calcium levels in response to the subsequent addition of agonists such as FMLP. PMNs primed with PAF and stimulated with either F-Met-Leu-Phe or phorbol esters are more effective in lysing and detaching cultured human endothelial cells--damage that can also be inhibited by the PAF antagonists. Because PAF is synthesized and exhibited on surfaces of endothelial cells perturbed by coagulation, we suggest that this lipid may potentiate otherwise trivial activators of marginated PMNs so that they become damaging to the PAF-synthesizing endothelium itself. If so, our studies suggest a possible therapeutic role for PAF inhibitors in excessive inflammatory states.     

Effects of an integrated Yoga Program on Self-reported Depression Scores in Breast Cancer Patients Undergoing Conventional Treatment: A Randomized Controlled Trial

Aim:

To compare the effects of yoga program with supportive therapy on self-reported symptoms of depression in breast cancer patients undergoing conventional treatment.

Patients and Methods:

Ninety-eight breast cancer patients with stage II and III disease from a cancer center were randomly assigned to receive yoga (n = 45) and supportive therapy (n = 53) over a 24-week period during which they underwent surgery followed by adjuvant radiotherapy (RT) or chemotherapy (CT) or both. The study stoppage criteria was progressive disease rendering the patient bedridden or any physical musculoskeletal injury resulting from intervention or less than 60% attendance to yoga intervention. Subjects underwent yoga intervention for 60 min daily with control group undergoing supportive therapy during their hospital visits. Beck''s Depression Inventory (BDI) and symptom checklist were assessed at baseline, after surgery, before, during, and after RT and six cycles of CT. We used analysis of covariance (intent-to-treat) to study the effects of intervention on depression scores and Pearson correlation analyses to evaluate the bivariate relationships.

Results:

A total of 69 participants contributed data to the current analysis (yoga, n = 33, and controls, n = 36). There was 29% attrition in this study. The results suggest an overall decrease in self-reported depression with time in both the groups. There was a significant decrease in depression scores in the yoga group as compared to controls following surgery, RT, and CT (P < 0.01). There was a positive correlation (P < 0.001) between depression scores with symptom severity and distress during surgery, RT, and CT.

Conclusion:

The results suggest possible antidepressant effects with yoga intervention in breast cancer patients undergoing conventional treatment.     

Characterization of 25 monoclonal antibodies to factor VIII-von Willebrand factor: relationship between ristocetin-induced platelet aggregation and platelet adherence to subendothelium

We have studied the role of factor VIII-von Willebrand factor (FVIII- vWF) in both platelet adherence to subendothelium and ristocetin- induced platelet aggregation using monoclonal antibodies to human FVIII- vWF. Twenty-five monoclonal antibodies were obtained, two of which were directed to the factor VIII moiety of FVIII-vWF; one of these two completely inhibited the procoagulant activity (FVIII:C). The remaining 23 monoclonal antibodies were directed to the von Willebrand factor moiety of FVIII-vWF. The ability of the latter monoclonal antibodies to inhibit platelet adherence to arterial subendothelium was investigated with a perfusion model. According to the number of platelets adhering to the subendothelium, three groups of monoclonal antibodies could be discerned: (A) antibodies not affecting platelet adherence; (B) antibodies that inhibited platelet adherence to the level as observed when von Willebrand's disease plasma was tested; and (C) antibodies that completely inhibited both platelet adherence to subendothelium and ristocetin-induced platelet aggregation. The two antibodies present in group C competed for the same or closely related epitope(s) present on FVIII-vWF. These results demonstrate that a domain is present on the FVIII-vWF molecule that is associated both with ristocetin-induced aggregation and with the ability of FVIII-vWF to support platelet adherence to the subendothelium. Based on these observations, it is concluded that ristocetin-induced binding of FVIII-vWF to platelets reflects, at least in part, a physiologic mechanism regulating the function of FVIII-vWF in primary hemostasis.     

Potential capsule switching from serogroup Y to B: The characterization of three such Neisseria meningitidis isolates causing invasive meningococcal disease in Canada

Three group B Neisseria meningitidis isolates, recovered from meningococcal disease cases in Canada and typed as B:2c:P1.5, were characterized. Multilocus sequence typing showed that all three isolates were related because of an identical sequence type (ST) 573. Isolates typed as 2c:P1.5 are common in serogroup Y meningococci but rare in isolates from serogroups B or C. Although no serogroup Y isolates have been typed as ST-573, eight isolates showed five to six housekeeping gene alleles that were identical to that of ST-573. This suggested that the B:2c:P1.5 isolates may have originated from serogroup Y organisms, possibly by capsule switching.Key Words: Capsule switching, Neisseria meningitidis, Serogroup YNeisseria meningitidis is a significant pathogen that causes invasive meningococcal disease (IMD). The average case fatality rate of 9% to 12% remains high despite the availability of effective antibiotics and vaccines (1). Laboratory study and surveillance of N meningitidis involves the characterization of a number of surface markers of the bacterium, including its capsule and outer membrane proteins (OMPs). Most epidemiological studies of meningococcal disease rely on differentiating meningococcal isolates based on their serogroup, serotype and serosubtype. Serogrouping is determined by the demonstration of serologically distinct epitopes present on chemically and structurally different capsules. Serotyping and serosubtyping rely on the detection of distinct epitopes present on three of five different classes of OMPs of N meningitidis. Serotyping epitopes are found on the class 2 or class 3 OMP (also called PorB) of N meningitidis; these OMPs are expressed in a mutually exclusively manner (ie, a strain will only express either a class 2 or class 3 OMP but not both). Serosubtyping epitopes are present on the class 1 OMP (also called PorA). Based on this nomenclature scheme, a strain can therefore be characterized by its antigenic formula; for example, B:15:P1.7,16 refers to serogroup B, serotype 15 and serosubtype P1.7,16.One of the most important virulence factors of meningococci is the capsular polysaccharide antigen, which is also the basis for serogrouping and is the target antigen for the currently licensed vaccines against A, C, Y and W135 organisms. Of the 13 known serogroups, five (serogroups A, B, C, Y and W135) are responsible for most of the meningococcal disease worldwide (2). In North America, most endemic and epidemic strains belong to serogroups B, C, Y and W135 (3,4). Capsules of serogroups B, C, Y and W135 meningococci contain sialic acid, either as a homopolymer of sialic acids assembled by alpha-2,8 linkages (serogroup B) or alpha-2,9 linkages (serogroup C), or as a heteropolymer of sialic acids with glucose (serogroup Y) or galactose (serogroup W135). Besides demonstrating structural similarities, these four serogroups of meningococci also have very similar capsule polysaccharide synthesis (cps) gene loci (5). Because of this similarity, capsule switching has been demonstrated in vivo and in vitro by specific gene replacement within the cps loci between different serogroups. To date, a number of IMD cases have been described in the literature to be caused by organisms in which capsule switching between serogroup B and C meningococci occurred (6-8).In the present paper, the authors describe three unusual serogroup B meningococci isolated from separate IMD cases in Nanaimo, British Columbia, that presented with the OMP antigens 2c:P1.5, characteristic of serogroup Y strains found in Canada (4). This antigenic profile prompted the authors to examine the relationship of these three serogroup B strains with antigenically similar serogroup Y organisms isolated in Canada. The authors describe the characterization of these antigenically similar isolates and postulate that the B:2c:P1.5 isolates arose by capsule switching from serogroup Y organisms.     

Mediastinal tuberculous lymphadenitis: CT manifestations

An analysis was done of computed tomographic (CT) scans of 23 Korean patients who had presented with a mediastinal or hilar mass on plain chest radiographs and had subsequently been found to have tuberculous lymphadenitis. Most patients were young adults. Findings of pulmonary tuberculosis were seen on plain radiographs in 14 patients. On CT, findings were of an overwhelming preponderance of involvement of the right paratracheal and tracheobronchial nodes. After injection of contrast medium, nodes larger than 2 cm in diameter invariably showed central areas of relative low density and peripheral rim enhancement. Enhanced walls were usually irregular in thickness. Some smaller nodes did not show low-density areas, but instead showed varying degrees of homogeneous enhancement. Although metastatic nodes can be of low density, experience in this study suggests that mediastinal lymphadenopathy in a young adult with the CT findings described above is characteristic enough to support a diagnosis of tuberculosis.     

New and developing anesthesia drugs

Introduction: In recent years, new anesthetic drugs with potentially better pharmacokinetic and pharmacodynamic properties are under development with good progress. Some of the most promising drugs are reviewed in this article.

Areas covered: A literature review was performed using Ovid and Medline as the search engine. Articles published from January 2000 to December 2016 were included for review. Efforts have been made to eliminate duplicated studies.

Expert opinion: This is an up-to-date review on new and developing anesthesia drugs. It will give readers information on the pharmacology and clinical significance of these new drugs.     

Phase II study of the farnesyltransferase inhibitor R115777 in advanced melanoma (CALGB 500104)

The benefits of exercise are well established but one major barrier for many is time. It has been proposed that short period resistance training (RT) could play a role in weight control by increasing resting energy expenditure (REE) but the effects of different kinds of RT has not been widely reported. We tested the acute effects of high-intensity interval resistance training (HIRT) vs. traditional resistance training (TT) on REE and respiratory ratio (RR) at 22 hours post-exercise. In two separate sessions, seventeen trained males carried out HIRT and TT protocols. The HIRT technique consists of: 6 repetitions, 20 seconds rest, 2/3 repetitions, 20 secs rest, 2/3 repetitions with 2′30″ rest between sets, three exercises for a total of 7 sets. TT consisted of eight exercises of 4 sets of 8–12 repetitions with one/two minutes rest with a total amount of 32 sets. We measured basal REE and RR (TT0 and HIRT0) and 22 hours after the training session (TT22 and HIRT22). HIRT showed a greater significant increase (p < 0.001) in REE at 22 hours compared to TT (HIRT22 2362 ± 118 Kcal/d vs TT22 1999 ± 88 Kcal/d). RR at HIRT22 was significantly lower (0.798 ± 0.010) compared to both HIRT0 (0.827 ± 0.006) and TT22 (0.822 ± 0.008). Our data suggest that shorter HIRT sessions may increase REE after exercise to a greater extent than TT and may reduce RR hence improving fat oxidation. The shorter exercise time commitment may help to reduce one major barrier to exercise.