Red blood cell mannoses as phagocytic ligands mediating both sickle cell anaemia and malaria resistance

In both sickle cell disease and malaria, red blood cells (RBCs) are phagocytosed in the spleen, but receptor-ligand pairs mediating uptake have not been identified. Here, we report that patches of high mannose N-glycans (Man_5-9GlcNAc₂), expressed on diseased or oxidized RBC surfaces, bind the mannose receptor (CD206) on phagocytes to mediate clearance. We find that extravascular hemolysis in sickle cell disease correlates with high mannose glycan levels on RBCs. Furthermore, Plasmodium falciparum-infected RBCs expose surface mannose N-glycans, which occur at significantly higher levels on infected RBCs from sickle cell trait subjects compared to those lacking hemoglobin S. The glycans are associated with high molecular weight complexes and protease-resistant, lower molecular weight fragments containing spectrin. Recognition of surface N-linked high mannose glycans as a response to cellular stress is a molecular mechanism common to both the pathogenesis of sickle cell disease and resistance to severe malaria in sickle cell trait.

A retrospective study of tuberculosis outcomes in Gulf Province, Papua New Guinea

Setting

Gulf Province, a rural area of mainland Papua New Guinea, is known to have one of the highest burdens of tuberculosis (TB) in the country.

Objectives

To describe the characteristics and outcomes of TB patients registered for first-line treatment in Kerema General Hospital in Gulf Province between January and December 2016.

Design

This was a retrospective cohort study using routinely collected programme data.

Results

Of 347 cases with a recorded TB site, 54% were male and 32% were aged <15 years. No human immunodeficiency virus (HIV) status was recorded for 51% of cases. TB was bacteriologically confirmed in 23% of cases. Among the cohort, there were 145 extrapulmonary TB cases (42%); the site of disease was unknown in 56% of these cases. Of the 297 cases with treatment outcome evaluated, 56% had a favourable outcome and 26% were lost to follow-up. On multivariable analysis, extrapulmonary TB (adjusted OR [aOR] 0.51, 95%CI 0.30-0.88, P = 0.02) and bacteriologically confirmed TB (aOR 0.40, 95%CI 0.21-0.77, P < 0.01) were associated with decreased odds of an unfavourable treatment outcome.

Conclusion

The study findings highlight the need to improve TB diagnosis, access to HIV testing, treatment adherence, patient support and the quality of TB programme data in Gulf Province.

Nodal disease predicts recurrence whereas other traditional factors affect survival in a cohort of South African patients with differentiated thyroid carcinoma

Background and aim

Information on patients with differentiated thyroid carcinoma in South Africa is limited. The objective of this study was to review demographics and tumour characteristics in a cohort of patients with differentiated thyroid carcinoma, presenting to Groote Schuur Hospital and evaluate risk factors for recurrence and survival.

Patients and methodology

Retrospective demographic and clinical data were collected on all patients referred between January 2003 and December 2013. Prognostic factors for recurrence free survival and cancer specific survival were assessed using univariate and multivariate analyses.

Results

The total number of patients was 231.The median age at presentation was 44 years and 82% were female patients. The pathological sub-types were papillary (60.6%), follicular (38.9%) and poorly differentiated (0.5%). Total thyroidectomy was performed in 191 patients and 30 patients required neck dissections. A total of 171 (74%) patients received ¹³¹Iodine. The recurrence free and cause specific survival rates at 10 years were 83 and 91%, respectively. Nodal disease at presentation was the only significant risk factor for recurrence (p <  0.001) on multivariate analysis. Significant risk factors for cause specific mortality were age ≥ 45 years (p = 0.006), follicular pathology (p = 0.004), extra-thyroid extension (p = 0.013) and residual tumour (p = 0.004).

Conclusions

Consistent with international trends, patients with differentiated thyroid carcinoma treated at Groote Schuur Hospital had a favourable prognosis. The known risk factors associated with recurrence and survival in this South African cohort were consistent with those reported in developed countries.

Requiem for Nigro or is anal squamous carcinoma still a surgical problem: Abdominoperineal excision rather than a defunctioning stoma?

BACKGROUND

Combined multimodal treatment (CMT) is the preferred treatment for anal squamous carcinoma with radical surgery reserved for treatment failure. Some patients require a defunctioning stoma prior to CMT. Successful closure of such a stoma is unlikely. Abdominoperineal excision (APE) may be suitable as primary treatment in these patients.

METHOD

A retrospective review of all patients with anal squamous carcinoma was undertaken. Patients who required defunctioning colostomies prior to CMT were analysed for potential resectability of tumour prior to CMT and rate of permanent stoma.

OBJECTIVE

To evaluate organ preservation in the treatment of anal squamous cancer and the closure rate of pre-treatment, temporary diverting colostomy, thereby assessing whether APE could be offered as primary treatment in those requiring a pre-treatment colostomy.

RESULTS

One hundred and twenty-five patients were included of which 58 were males. The mean age was 56 years. 107 were treated with curative intent. Six received primary APE and 12 salvage APE. Thirty (22 males) required pretreatment diverting colostomies. Three (10%) stomas were successfully reversed. Forty-eight (38%) of the 125 completed treatment with a permanent colostomy. Six patients who needed a stoma prior to CMT were deemed resectable.

CONCLUSION

Organ preservation was not possible in about a third of patients. Defunctioning stomas prior to CMT were likely to be permanent. We propose that APE could be considered as an alternative in selective cases where the tumour is resectable with low morbidity and a stoma is indicated.

Uncovering the structure of the mouse gait controller: Mice respond to substrate perturbations with adaptations in gait on a continuum between trot and bound

Animals, including humans, have been shown to maintain a gait during locomotion that minimizes the risk of injury and energetic cost. Despite the importance of understanding the mechanisms of gait regulation, ethical and experimental challenges have prevented full exploration of these. Here we present data on the gait response of mice to rapid, precisely timed, spatially confined mechanical perturbations. Our data elucidate that after the mechanical perturbation, the mouse gait response is anisotropic, preferring deviations away from the trot towards bounding, over those towards other gaits, such as walk or pace. We quantified this shift by projecting the observed gait onto the line between trot and bound, in the space of quadrupedal gaits. We call this projection λ. For λ=0, the gait is the ideal trot; for λ=±π, it is the ideal bound. We found that the substrate perturbation caused a significant shift in λ towards bound during the stride in which the perturbation occurred and the following stride (linear mixed effects model: Δλ=0.26±0.07 and Δλ=0.21±0.07, respectively; random effect for animal, p < 0.05 for both strides, n = 8 mice). We hypothesize that this is because the bounding gait is better suited to rapid acceleration or deceleration, and an exploratory analysis of jerk showed that it was significantly correlated with λ (p < 0.05). Understanding how gait is controlled under perturbations can aid in diagnosing gait pathologies and in the design of more agile robots.

Effect of Venous Occlusion on Coagulation and Fibrinolytic Components in Normal Subjects

The components of the coagulation and fibrinolytic systems were studied before and during venous occlusion for 20 min of the arm and of the leg in 30 healthy volunteers. For comparison total serum proteins, α2-macroglobulin and albumin were also determined. The values recorded after venous occlusion were corrected according to the changes in the haematocrit.

The fibrinolytic activity induced by venous occlusion was markedly higher (4 to 6 times) in the arms than in the legs. In 2 of the subjects, however, venous occlusion was not followed by any increase of fibrinolysis.

After venous occlusion total serum proteins increased by 15% but albumin only by 2%. The P & P, AHF, haemophilia B-factor and fibrinogen increased by 5-20%. The factor V-level remained unchanged. The AHF and factors XI and XII increased by about 20% in the legs but by about 40% in the arms. In other respects the upper and lower limbs showed the same type of coagulation changes.

The plasminogen level increased in both arms and legs by 10%. The inhibitors of urokinase activation and the α2M remained unchanged, which means that these inhibitors compared with the increase in total serum proteins had decreased by about 10%.

The 2 normals, in whom venous occlusion failed to produce any increase of fibrinolysis, had no signs of Hageman trait and after venous stasis the same coagulation changes occurred as in the individuals who developed high fibrinolytic activity.

The findings argue against the Hageman factor playing an essential role in the activation of the fibrinolytic system during venous occlusion and indicate that the increase in fibrinolysis is due to release of activators from the vessel walls.

Fibrinolytic Activity of Human Veins in Arms and Legs

A modification of the fibrin slide method of Todd permitting a semiquantitative estimation of the fibrinolytic activity in tissue sections is described. By means of this technique, the authors have studied the fibrinolytic activity of the great saphenous vein and of superficial veins of the arm and leg in patients suffering from varices and in normal subjects. It was found that:

1. Fibrinolytic activity is localized, in these vessels, mainly to the vasa vasorum of the adventitia. The media is moderately active. Intimal cells are active only when detached.

2. The great saphenous vein is more active above than below the knee.

3. The veins of the arm are definitely more active than the veins of the leg.

4. The activator of plasminogen demonstrated in the sections by the fibrin slide method is a fairly stable enzyme still active after exposure to 60° C and resistent to moderate variations of pH.

Determination of Plasminogen in Clots and Thrombi

The plasminogen content was determined by a casein method in plasma and serum from 20 normal volunteers. The mean plasminogen content was found to be 10.1 ACU (the arbitrary caseinolytic unit defined in such a way that using a 3% casein solution and a digestion time of 20 min. at 37°C, 10 ACU gave an extinction of 0.300). No difference between serum and plasma regarding the plasminogen content was found.

Plasminogen was determined in drained and drained plus washed clots prepared from 2 ml plasma. The highest values found in the drained clots were 0.9 ACU/clot and 0.2 ACU/clot in the drained plus washed clots.

Plasminogen was also determined in drained and drained plus washed clots prepared from plasma with added purified plasminogen. The plasminogen was recovered in the washing fluid. According to these tests, then, purified added plasminogen is washed out of the clots.

The plasminogen content of 20 thrombi obtained post mortem was also determined. The mean value was found to be 0.7 ACU/cm thrombus. Judging from our results, the “intrinsic clot lysis theory” is not the main mechanism of clot dissolution.

Suppressive Effect of Dextran on Platelet Adhesiveness

43 normal volunteers, 3 patients with thrombophlebitis, and 1 patient with a high platelet adhesiveness and a history of thrombophlebitis have received dextran and its action on the mechanism of haemostasis has been studied. Platelet adhesiveness has been investigated by a slight modification of Hellem’s methods for whole blood and plasma. Dextran with a mean molecular weight of 70,000 produced a markedly lowered platelet adhesiveness together with a moderate prolongation of the Ivy bleeding time. Factor VIII was decreased by about 50% and factor V, factor IX and fibrinogen were decreased slightly more than could be expected from haemodilution alone. No fibrinolysis occurred. Dextran of lower molecular size was less potent. The possible use of dextrans as a thrombosis prophylactic agent is discussed.

Radiologic Observations in Severe Neonatal Respiratory Distress Syndrome Treated with the Isolated Phospholipid Fraction of Natural Surfactant

Ten newborn babies with severe respiratory distress syndrome, all dependent on artificial ventilation, were treated via the airways with the isolated phospholipid fraction of bovine or porcine surfactant. After treatment with surfactant at a median age of 10.5h, there was in all patients a striking improvement of lung aeration in chest films, with a decrease in parenchymal fluid retention and in distension of bronchioli. These radiologic findings were associated with a dramatic improvement of oxygenation and a significant reduction of the right-to-left shunt. In spite of the rapid therapeutic response, four patients died from cerebral hemorrhage. One of the surviving patients developed bronchopulmonary dysplasia. Our findings document efficacy of this new surfactant preparation in the neonatal respiratory distress syndrome, but the long-term effects need to be further tested in randomized clinical trials.

Construct validity of the FOCUS© (Focus on the Outcomes of Communication Under Six): a communicative participation outcome measure for preschool children

OBJECTIVE

The aim of this study was to establish the construct validity of the Focus on the Outcomes of Communication Under Six (FOCUS©). This measure is reflective of concepts in the International Classification of Functioning Disability and Health--Children and Youth framework. It was developed to capture 'real-world' changes (e.g. communicative participation) in preschoolers' communication following speech-language intervention.

METHOD

A pre-post design was used. Fifty-two parents of 3- to 6-year-old preschoolers attending speech-language therapy were included as participants. Speech-language therapists provided individual and/or group intervention to preschoolers. Intervention targeted: articulation/phonology, voice/resonance, expressive/receptive language, play, and use of augmentative devices. Construct validity for communicative participation was assessed using pre-intervention and post-intervention parent interviews using the FOCUS© and the communication and socialization domains of the Vineland Adaptive Behavior Scales-II (VABS-II).

RESULTS

Significant associations were found between the FOCUS©, measuring communicative participation, and the VABS-II domains for: (i) pre-intervention scores in communication (r = 0.53, P < 0.001; 95% CI 0.30-0.70) and socialization (r = 0.67, P < 0.001; 95% CI 0.48-0.80); (ii) change scores over-time in communication (r = 0.45, P < 0.001; 95% CI 0.201-0.65) and socialization (r = 0.39, P = 0.002; 95% CI 0.13-0.60); and (iii) scores at post-intervention for communication (r = 0.53, P < 0.001; 95% CI 0.30-0.70) and for socialization (r = 0.37, P = 0.003; 95% CI 0.11-0.50).

CONCLUSIONS

The study provided evidence on construct validity of the FOCUS© for evaluating real-world changes in communication. We believe that the FOCUS© is a useful measure of communicative participation.

Measuring communicative participation using the FOCUS©: Focus on the Outcomes of Communication Under Six

BACKGROUND

The FOCUS© is a new outcome tool for use by both parents and clinicians that measures changes in the communicative participation skills of preschool children. Changes in communicative participation skills as measured by the FOCUS were compared across three groups of children: those with speech impairments only (SI), those with language impairments only (LI) and those with both speech and language impairments (S/LI).

METHODS

Participating families (n = 112, 75 male children) were recruited through 13 Canadian organizations. Children ranged from 10 months to 6 years 0 months (mean = 2.11 years; SD = 1.18 years) and attended speech-language intervention. Parents completed the FOCUS at the start and end of treatment. There were 23 children in the SI group, 62 children in the LI group and 27 children in the S/LI group. The average amount of the children's therapy varied from 7 to 10 h.

RESULTS

The FOCUS captures changes in communicative participation for children with a range of communication disorder types and severities. All three groups of children made clinically important improvements according to their FOCUS scores (MCID ≥ 16 points). The FOCUS captured improvements in intelligibility, independent communication, play and socialization.

CONCLUSIONS

The FOCUS measured positive changes in communicative participation skills for all three groups of children after 7-10 h of speech-language therapy. An outcome measure that targets only specific speech and language skills would miss many of the important social function changes associated with speech-language treatment.

Self-assembled hierarchical nanostructures composed of novel chalcopyrite nanosheets for photovoltaic properties

Self-assembled nanostructures of CulnGaSe2 (CIGS) comprising of nanosheets with sheet thickness of 20 nm have been developed via one-step electrochemically alloying technique. These self-assembled nanoplates exhibit highly intersecting behavior and transform from CuSe to CIGS as the reduction potential was varied. The morphological analysis indicated that the process resulted in a progression of crystallites to a series of heavy dense intersecting nanoplates. Further analyses revealed that the nanostructures keep their integrity on heat treatment. The structure confirms the inclusion of Indium and Gallium at higher reduction potentials and its transition from pseudoamorphous to polycrystalline structure. A strong correlation between reduction potential, and the composition was established. The spectroscopic and optical spectra clearly prove that the direct band gap for the as-grown and annealed thin films, and appropriate for solar cell applications. These self-assembled dense interweaved nanoplates structure have not been observed previously in CIGS semiconductor system and have potential implications forenergy applications.

Platelet and coagulation activation markers in myeloproliferative diseases: relationships with JAK2 V6I7 F status, clonality, and antiphospholipid antibodies

BACKGROUND AND OBJECTIVES

Patients with myeloproliferative disease (MPD) have an increased risk of thrombosis. We studied markers of platelet and coagulation activation in a large cohort of patients with MPD (n = 118) and related this to Janus Kinase 2 (JAK2) V617 F mutation status, a marker of clonality, and the presence of antiphospholipid antibodies (APA), all of which have been associated with thrombosis in MPD.

METHODS

D-dimer, thrombin-antithrombin complexes (TAT), prothrombin fragments 1 + 2 (F(1+2)), soluble E-selectin (sE-selectin), and soluble P-selectin (sP-selectin) levels were compared between patients and hypertensive controls (n = 127). Assays for lupus anticoagulant (LA), anticardiolipin antibodies (ACA), antibeta2 glycoprotein 1 antibodies (anti-beta(2)GP1), and antiprothrombin antibodies (alpha-Pro) were also performed. The JAK2 V617F mutation status was determined in the cohort using amplification refractory mutation system (ARMS) polymerase chain reaction. Disease clonality was determined in 54 patients using the HUMARA assay.

RESULTS

sP-selectin was significantly increased in patients with MPD (P

CONCLUSIONS

The JAK2 V617F mutation is associated with platelet activation, as measured by elevated sP-selectin levels, in MPD. In contrast to previous reports, we found no excess of APA in patients with MPD.

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MESH Headings

• Adult
• Aged
• Aged, 80 and over
• Antibodies, Antiphospholipid/chemistry
• Blood Coagulation
• Blood Platelets/cytology
• Blood Platelets/metabolism
• Cohort Studies
• Female
• Humans
• Janus Kinase 2/genetics
• Male
• Middle Aged
• Myeloproliferative Disorders/genetics
• Myeloproliferative Disorders/metabolism
• Thrombosis/genetics

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Population pharmacokinetics of mefloquine in military personnel for prophylaxis against malaria infection during field deployment

OBJECTIVE

The purpose of this study was to determine the population pharmacokinetics of mefloquine in healthy military personnel during prophylaxis for malaria infections.

METHODS

The subjects were 1,111 Australian soldiers participating in two studies: a randomised double-blinded study (group A, 161 subjects) and an open-label study (group B, 950 subjects). Following a loading dose (250 mg mefloquine base daily, 3 days), subjects received an oral weekly maintenance dose of 250 mg over 6 months. Blood was collected after the last split loading dose then at weeks 4, 8 and 16 for group A, and at weeks 13 and 26 for group B. Plasma mefloquine concentrations were measured by high-performance liquid chromatography (HPLC). Pharmacokinetic modelling was performed using NONMEM.

RESULTS

A two-compartment model with inter-occasion variability (IOV) for clearance satisfactorily described the pharmacokinetics. Typical values were clearance (CL/F, 2.09 l/h), central volume of distribution (V1/F, 528 l), absorption rate constant (KA, 0.24 h(-1)), inter-compartmental clearance (Q/F, 12.5 l/h), peripheral volume of distribution (V2/F, 483 l) and elimination half-life (t (1/2), 14.0 days). Weight had a positive influence on central volume but was insufficient to warrant dosage adjustments. The inter-individual variability (coefficient of variation, CV%) for CL/F and V1/F was 24.4% and 29.6%, respectively. The IOV for CL/F was 17.8%. The proportional residual error (CV%) for groups A and B was 11.5% and 19.5%, respectively, and the additive error standard deviation (SD) was 57 ng/ml and 149 ng/ml, respectively.

CONCLUSION

The typical parameter values were comparable with those estimated in much smaller cohorts of healthy subjects and in malaria patients treated with single-dose mefloquine. The lower unexplained variability in the blinded study suggested these subjects may have been more compliant in taking their medication than soldiers in the open-label study.

Antiphospholipid syndrome: An evolving story

Antiphospholipid Syndrome (APS) is a form of immune mediated thrombophilia, presenting as recurrent thrombotic events and pregnancy morbidity, in association with positive laboratory tests for antiphospholipid antibodies (APA) in the form of Lupus Anticoagulant (LA) or anticardiolipin antibodies(ACA). Insights into the pathophysiology of the condition suggest that some antibodies are prothrombotic in vivo, and that the mechanism of thrombosis is likely to be multifactorial. APS has a broad spectrum of clinical presentations, and the laboratory diagnosis can be difficult due to heterogeneity of APAs and poor standardisation of laboratory tests. Anticoagulation is the mainstay of the management of the thrombotic and obstetric complications of APS. The risk of recurrent thrombosis appears to be high, and the duration and intensity of therapy remains controversial. Randomised controlled trials have shown that standard intensity anticoagulation is adequate in most cases of venous thrombosis. Further trials are required to establish whether high intensity coagulation is of benefit in recurrent or arterial thrombosis. The optimal management of recurrent fetal loss is debated and large studies are required to establish a clear benefit of heparin and aspirin over aspirin alone or supportive care.