FN-C1q and C1 INH C1r-C1s complexes as indicators of complement activation in patients with chronic lymphocytic leukaemia

We have previously found low levels of C1 and C4 INH in the sera of chronic lymphocytic leukaemia (CLL) patients. Hypocomplementaemia was supposed to be the consequence of a permanent activation of the classical pathway. We have compared the levels of C1 INH-C1rC1s and C1q-FN complexes in the sera of 95 CLL patients and 100 healthy controls, because these complexes are known to be formed in the early stage of classical pathway activation. A significant increase in the level of both types of complexes was found in sera of CLL patients as compared to the controls. These findings support the assumption that the classical complement pathway is activated in the patients with CLL.     

A Synthetic Bioactive Peptide Derived from the Asian Medicinal Plant Acacia catechu Binds to Dengue Virus and Inhibits Cell Entry

Dengue virus (DENV) infection has become a critically important globally prevalent infectious disease, especially in tropical and subtropical countries. Since neither currently exists, there is an urgent need for an effective vaccine to prevent, and a specific drug to treat DENV infection. Therapeutic peptides represent an attractive alternative for development into anti-DENV drugs due to their safety and their diverse biological and chemical properties. We recently reported novel bioactive peptides extracted from the Asian medicinal plant Acacia catechu that efficiently inhibited all four DENV serotypes. In this study, we investigated the anti-DENV activity of a synthetic bioactive peptide derived from this plant. The most effective peptide (designated Pep-RTYM) inhibited DENV infection with a half-maximal inhibition concentration value of 7.9 μM. Time-of-addition study demonstrated that Pep-RTYM interacted with DENV particles and inhibited cellular entry. Pep-RTYM at 50 μM significantly reduced DENV production in Vero-kidney epithelial cells about 1000-fold, but it could decrease the virus production in Huh7 hepatocyte cells approximately 40-fold. Binding of Pep-RTYM to DENV particles may prevent virus interaction with cellular receptor and subsequent virus entry. This finding suggests a potential role of Pep-RTYM in the development of a novel anti-DENV drug.     

Reference values for thrombotic markers in children

Thromboembolic events are an increasingly common problem encountered in children. The laboratory diagnosis of thrombotic disorders in children differs from that in adults. To establish the normal reference of natural anticoagulant parameters in children of different age groups, plasma from healthy children between the ages of 2 months and 16 years (n = 127) and adults (n = 30) were assayed for a disintegrin-like and metalloprotease with thrombospondin type 1 domain 13 (ADAMTS-13), von Willebrand factor collagen-binding activity (vWF:CB), tissue factor pathway inhibitor (TFPI), homocyteine and natural anticoagulants. Children were divided into four age groups: less than 1 year, 1-5 years, 6-10 years, and 11-16 years. The reference values for ADAMTS 13, homocysteine, and protein C activity were significantly lower in children of all age groups compared with those in the adults. Similarly, those for protein C antigen, total protein S, free protein S and antithrombin III (AT III) for children less than 1 year were significantly lower than in the adults. On the contrary, TFPI levels were significantly higher in the children for all age groups when compared with the adults. vWF:CB levels were comparable across all groups. There are age-related physiologic differences in ADAMTS-13, TFPI, homocysteine and natural anticoagulants between children and adults. Our data will provide physicians with a useful reference guide in interpreting test results of inhibitors of hemostatic parameters in children suspected of thrombotic disorders.     

A Peptide Inhibitor Derived from the Conserved Ectodomain Region of DENV Membrane (M) Protein with Activity Against Dengue Virus Infection

Dengue virus (DENV) infection is a public health problem worldwide; thus, the development of a vaccine and anti‐DENV drugs is urgently needed. It has been observed that low levels of viremia in DENV‐infected individuals are associated with mild disease outcomes; therefore, reduction of DENV load should offer therapeutic benefits. Disruption of protein–protein interactions on the surface of DENV by a peptide that mimics part of its structural protein may affect stability of the virion structure and inhibit viral entry into host cells. To test this hypothesis, we generated a novel peptide inhibitor that mimics the conserved ectodomain region of DENV membrane (M) protein, MLH40 peptide, for DENV inhibition assays. MLH40 inhibited all four serotypes of the virus (DENV1–4) at half maximal inhibition concentration of 24–31 μm . MLH40 at 100 μm blocked DENV2 attachment to cells by 80%. The inhibitory activity of MLH40 against DENV was consistently observed with different cell types, including Vero, A549, and Huh7 cells. Prediction of MLH40 binding by a molecular docking program indicated that its N‐terminal loop may interact with DENV envelope (E) proteins and alter their dimer conformation. Thus, MLH40 may serve as a lead‐peptide inhibitor for the development of an anti‐DENV drug.     

Environmental surface chemistries and adsorption behaviors of metal cations (Fe3+, Fe2+, Ca2+ and Zn2+) on manganese dioxide-modified green biochar

The facile preparation and modification of low-cost/efficient adsorbents or biochar (CP) derived from the carbonization of palm kernel cake (lignocellulosic residue) has been studied for the selective adsorption of various metal cations, such as Fe³⁺, Fe²⁺, Ca²⁺ and Zn²⁺, from aqueous solution. The CP surface was modified with KMnO₄ (CPMn) and HNO₃ (CPHNO₃) in order to improve the adsorption efficiency. The physicochemical properties of the as-prepared adsorbents were investigated via BET, pH_pzc, FT-IR, Boehm titration, TG-DTG, XRD and SEM-EDS techniques. The surfaces of all adsorbents clearly demonstrated negative charge (pH_pzc > pH of the mixture solution), resulting in a high adsorption capacity for each metal cation. Fe²⁺ was found to be more easily adsorbed on modified CP than the other kinds of metal cations. Synergistic effects between the carboxylic groups and MnO₂ on the surface of CPMn resulted in better performance for metal cation adsorption than was shown by CPHNO₃. The maximum adsorption capacities for Fe³⁺, Fe²⁺, Ca²⁺ and Zn²⁺ using CPMn, which were obtained from a monolayer adsorption process via Langmuir isotherms (R² > 0.99), were 70.67, 68.60, 5.06 and 22.38 mg g⁻¹, respectively. The adsorption behavior and monolayer-physisorption behavior, via a rapid adsorption process as well as single-step intra-particle diffusion, were also verified and supported using Dubinin–Radushkevich, Redlich–Peterson and Toth isotherms, a pseudo-second-order kinetic model and the Weber–Morris model. Moreover, the thermodynamic results indicated that the adsorption process of metal cations onto the CPMn surface was endothermic and spontaneous in nature. This research is expected to provide a green way for the production of low-cost/efficient adsorbents and to help gain an understanding of the adsorption behavior/process for the selective removal of metal ions from wastewater pollution.

Manganese dioxide-modified green biochar exhibited excellent capacity for adsorption of Fe³⁺, Fe²⁺, Ca²⁺ and/or Zn²⁺.     

Red Cell Indices and Formulas Used in Differentiation of β-Thalassemia Trait from Iron Deficiency in Thai School Children

Red cell indices and formulas have been established as simple, fast, and inexpensive means for discrimination between the β-thalassemia (β-thal) trait and iron deficiency. However, there were no reports of the diagnostic reliability of different red cell indices and formulas in discrimination of β-thal trait from iron deficiency in the Thai population. The aim of this study was to examine the diagnostic accuracy of five red cell indices [red blood cell (RBC) count, mean corpuscular volume (MCV), mean corpuscular hemoglobin (Hb) (MCH), mean corpuscular Hb concentration (MCHC), and red cell distribution width (RDW)] and eight formulas (Sirdah, Green & King, RDW Index, Menzler, England & Fraser, Ehsani, Srivastava, and Shine & Lal). Their sensitivity, specificity, positive and negative prognostic value and efficiency, were analyzed in 77 Thai school children, 21 with the β-thal trait and 56 with iron deficiency. The Sirdah and Srivastava formulas proved to be the most reliable indexes as they had 100.0% sensitivity and negative predictive value, the highest efficiency (97.4%), and the highest Youden’s Index value (96.4%). Therefore, these formulas could be used in initial discrimination of the β-thal trait from iron deficiency in Thai school children.     

Cord blood collection for the National Cord Blood Bank in Thailand

Umbilical cord blood is an effective alternative source of hematopoietic stem cells transplantation in children and adolescents. However, the efficacy and safety of cord blood transplantation correlates with the quantity and quality of cord blood. To evaluate the collection systems and processing of cord blood donations, a pilot research program to optimize recruitment, collection and processing of cord blood donations was developed. The present results showed that the quality of the cord blood (volume, total white blood cells (WBC) count, CD34+ and sterility control) collected was satisfactory and discard rate of collecting units (24.2%) were comparable with data reported from other cord blood banks. To find the optimal mode of collection, comparison of 3 cord blood collection methods (Method 1 = Hanging method after delivering the placenta, Method 2 = Aspiration from in utero placenta, Method 3 = Aspiration from in utero placenta and Syringe-assisted aspiration) using the closed system showed that method 3 was the best method but it required more trained personnel and involved a complicated procedure. The National Cord Blood Bank started its activity in 2002 after several years of pre-clinical studies. To date, a number of transplants using cord blood from related and unrelated cord blood (first report in Thailand) donors have been successfully performed.     

Congenital dislocation of the patella

Purpose Congenital dislocation of the patella is permanent and manually irreducible, and it manifests immediately after birth with flexion contracture of the knee, genu valgus, external tibial torsion and foot deformity. We retrospectively reviewed the results of operative treatment of seven knees in six patients with congenital dislocation of the patella. Methods The age of the six patients at diagnosis ranged from 8 days to 3.6 years, with an average of 1.3 years, and their age at the time of operation ranged from 0.6 to 3.9 years, with an average of 2.1 years. Serial casting and/or a brace was attempted before surgery in five of seven knees, leading to improvement in the flexion contracture of the knee. All knees were treated operatively in combination with lateral release, medial plication, V-Y lengthening of the quadriceps, medial transfer of the lateral patellar tendon and posterior release of the knee. Results Although these deformities were noticed at birth in all seven knees, diagnosis was delayed in three knees due to the low suspicion of the disease and invisible patellae on radiographs. Ultrasonography confirmed the diagnosis of dislocation. The patella was centered in the groove of the femoral condyle after surgery in all knees, but subluxation of the knee with flexion was observed in one knee in which the operation was performed at 3.9 years. Genu valgus and external tibial torsion improved after surgery in all knees. The operated knee was mobile in all cases, with less than 10° flexion contracture of the knee. Flexion contracture did not increase in any of the knees. Conclusion Congenital dislocation of the patella should be suspected in every patient with knee flexion contracture, genu valgus, external tibial torsion, foot deformity and delayed walking. Successful results were obtained when the operation was performed in younger children. Other procedures, such as the semitendinosus tenodesis or tendon transfer, might have to be combined to achieve better stability with flexion in older children. None of the authors received financial support for this study.     

Mismatch analysis of humeral nailing: antegrade versus retrograde insertion

Background  

Closed humeral nailing is now considered an alternative treatment for humeral-shaft fracture. The nail can be inserted with either the antegrade or retrograde method. We investigated and compared the problem of geometric mismatch of the humeral nail to the humerus between the two methods of insertion.     

Neuroprotection of ischemic brain by vascular endothelial growth factor is critically dependent on proper dosage and may be compromised by angiogenesis.

Vascular endothelial growth factor (VEGF) is currently considered a potential pharmacologic agent for stroke therapy because of its strong neuroprotective and angiogenic capacities. Nonetheless, it is unclear how neuroprotection and angiogenesis by exogenous VEGF are related and whether they are concurrent events. In this study, the authors evaluated by stereology the effect of VEGF on neuronal and vascular volume densities of normal and ischemic brain cortices of adult male Sprague-Dawley rats. Ischemia was induced by a 4-hour occlusion of the middle cerebral artery. Low, intermediate, and high doses of VEGF165 were infused through the internal carotid artery for 7 days by an indwelling osmotic pump. The low and intermediate doses, which did not induce angiogenesis, significantly promoted neuroprotection of ischemic brains and did not damage neurons of normal brains. In contrast, the high dose that induced angiogenesis showed no neuroprotection of ischemic brains and damaged neurons of normal brains. These findings suggest that in vivo neuroprotection of ischemic brains by exogenous VEGF does not necessarily occur simultaneously with angiogenesis. Instead, neuroprotection may be greatly compromised by doses of VEGF capable of inducing angiogenesis. Stroke intervention efforts attempting to induce neuroprotection and angiogenesis concurrently through VEGF monotherapy should be approached with caution.