Physiological Effects of a Novel Immune Stimulator Drug, (1,4)‐α‐d‐Glucan,in Rats

Abstract: The (1,4)‐α‐d ‐glucan (α‐d ‐glucan), derived from medicinal plant, Tinospora cordifolia, activates human lymphocytes with downstream synthesis of the pro‐ and anti‐inflammatory cytokines, in vitro. We investigated physiological and immunological effects of a low and a high dose of α‐d ‐glucan (0.5 and 10 mg/kg), in vivo, testing the hypothesis that intravenous administration of α‐d ‐glucan does not affect haemodynamic, respiratory, haematological, and immune responses in normal rats. Male rats (300–400 g) were anaesthetized, tracheostomized, and catheterized in one femoral artery and vein. The mean arterial blood pressure and heart rate were continuously recorded. The baselines for gas exchange, differential blood cell count, and plasma concentration of TNF‐α, IL‐1β, IL‐4, IL‐6, and IFN‐γ were determined. Rats were then randomly assigned to controls (n = 7), a low dose (0.5 mg/kg; n = 10), and a high dose (10 mg/kg; n = 7) of α‐d ‐glucan for a six 6 hr study period. Gas exchange, differential cell count, plasma concentration of TNF‐α, IL‐1β, IL‐4, IL‐6, and IFN‐γ, and mean arterial blood pressure values remained within physiological range. Intravenous administration of 10 mg/kg α‐d ‐glucan created tachycardia, associated with hyperventilation, and significant reductions in the blood haemoglobin and haematocrit concentrations. We suggest that these in vivo effects of α‐d ‐glucan should be considered for future clinical and/or experimental trials.     

Impact of Mucorales and Other Invasive Molds on Clinical Outcomes of Polymicrobial Traumatic Wound Infections

Combat trauma wounds with invasive fungal infections (IFIs) are often polymicrobial with fungal and bacterial growth, but the impact of the wound microbiology on clinical outcomes is uncertain. Our objectives were to compare the microbiological features between IFI and non-IFI wounds and evaluate whether clinical outcomes differed among IFI wounds based upon mold type. Data from U.S. military personnel injured in Afghanistan with IFI wounds were examined. Controls were matched by the pattern/severity of injury, including blood transfusion requirements. Wound closure timing was compared between IFI and non-IFI control wounds (with/without bacterial infections). IFI wound closure was also assessed according to mold species isolation. Eighty-two IFI wounds and 136 non-IFI wounds (63 with skin and soft tissue infections [SSTIs] and 73 without) were examined. The time to wound closure was longer for the IFI wounds (median, 16 days) than for the non-IFI controls with/without SSTIs (medians, 12 and 9 days, respectively; P < 0.001). The growth of multidrug-resistant Gram-negative rods was reported among 35% and 41% of the IFI and non-IFI wounds with SSTIs, respectively. Among the IFI wounds, times to wound closure were significantly longer for wounds with Mucorales growth than for wounds with non-Mucorales growth (median, 17 days versus 13 days; P < 0.01). When wounds with Mucorales and Aspergillus spp. growth were compared, there was no significant difference in wound closure timing. Trauma wounds with SSTIs were often polymicrobial, yet the presence of invasive molds (predominant types: order Mucorales, Aspergillus spp., and Fusarium spp.) significantly prolonged the time to wound closure. Overall, the times to wound closure were longest for the IFI wounds with Mucorales growth.     

Genetic backgrounds of the Plasmodium falciparum chloroquine resistant transporter (pfcrt) alleles in Pakistan

Chloroquine (CQ) resistance in Plasmodium falciparum has been associated with point mutations in the P. falciparum CQ resistance transporter gene (pfcrt). Previous studies have shown 4-5 independent origins for CQ resistant pfcrt alleles globally, two in South America, one each in Southeast Asia, Papua New Guinea (PNG) and Philippines. In Asia, at least two different alleles corresponding to amino acids 72-76 (CVIET and SVMNT) have been found. The CVIET allele originated in Southeast Asia and then spread to Asia and Africa as well. The SVMNT allele, originating from PNG, has been found in India. This study was undertaken to investigate the genetic background of the CQ resistant pfcrt haplotypes in Pakistan. We genotyped microsatellite markers surrounding the pfcrt gene (six different markers at -12.3, -4.8, -1, 1.5, 3.9, 18.8 kb) in 114 clinical isolates of P. falciparum collected from different regions in Pakistan. Microsatellite analysis showed a significant reduction in genetic variation among the mutant SVMNT pfcrt alleles when compared to wild type alleles. The predominant SVMNT haplotype found in this study shared the same microsatellite haplotype found in both PNG and India. Two isolates with CVIET haplotypes showed similar microsatellite background to those found in Africa and Asia. In conclusion, this study suggests that CQ resistant SVMNT haplotypes in India and Pakistan have a common ancestral origin similar to that of Papua New Guinean isolates.     

Anemia and the potential role of erythropoiesis-stimulating agents in heart failure

The recognition of the high prevalence and the independent prognostic role of anemia in heart failure (HF) has contributed to intensification of the search for an effective treatment. A central role of erythropoietin in cardiorenal anemia syndrome has been proposed. Several clinical trials have established the safety and efficacy of erythropoiesis-stimulating agents in correcting anemia in patients with HF. The recognition of the pleiotropic effect of erythropoietin has expanded targets of therapy. The ongoing outcomes trial with darbepoetin alfa will determine the role of this novel therapy in the treatment of HF.     

Left Ventricular Unloading During Extracorporeal Membrane Oxygenation in Patients With Cardiogenic Shock

Background

Venoarterial extracorporeal membrane oxygenation (VA-ECMO) is a widely used form of mechanical circulatory support in patients with refractory cardiogenic shock. A common drawback of this modality is a resultant increase in left ventricular afterload.