Effect on some haematological indices of human whole blood when aqueous leaf extract of Euphorbia heterophylla was used as storage anticoagulant

Properties of red blood cells, especially cell size and red cell indices related to size, change with time in stored blood samples. Laboratory anticoagulants have certain drawbacks. For example, heparin has no preservative property on whole blood while K3EDTA (EDTA) is toxic and damages platelets. The search for novel anticoagulants with better hematological profile is therefore necessary. The anticoagulant properties of aqueous leaf extract of Euphorbia heterophylla (aka ito in Igbo) were compared with those of K3EDTA. Specifically, the effect of this extract and K3EDTA on packed cell volume (PCV) and red cell indices related to size, when they were used as anticoagulants, were compared. 0.5 ml of serial dilutions of this extract were placed in specimen bottles containing 2 ml fresh human whole blood and stored for 15 days at 4°C. For control, 2 ml fresh human whole blood was added to specimen bottles containing 1.5 mg/ml EDTA and stored for 15 days at 4°C. Thereafter, the test and control samples were analyzed for PCV, MCV, MCH and MCHC using haematology autoanalyser (Erma Inc, PCE - 210). All concentrations of the extract used, except 65 mg/ml, and the K3EDTA were able to keep the blood samples in fluid state throughout the 15 days period of storage. At the level of significance, p < 0.05, this extract had comparable preservative effect on MCV and MCH (p = 0.79; 0.20), but less preservative effect on PCV and MCHC when compared with EDTA (p = 0.013; 0.049). The aqueous leaf extract of Euphorbia heterophylla has preservative properties on haematological indices of stored human whole blood compare to that of K3EDTA. The fact that it does not chelate calcium as its mechanism of anticoagulation gives it an advantage over K3EDTA when used for biochemical tests. It should therefore, be explored as alternative laboratory anticoagulant in view of this advantage.Keywords: Euphorbia heterophylla, anticoagulants, storage of blood, red cell indices, K3EDTA.African Journal of Biotechnology Vol. 12(31), pp. 4952-495

Molecular Binding Mechanism of TtgR Repressor to Antibiotics and Antimicrobials

A disturbing phenomenon in contemporary medicine is the prevalence of multidrug-resistant pathogenic bacteria. Efflux pumps contribute strongly to this antimicrobial drug resistance, which leads to the subsequent failure of clinical treatments. The TtgR protein of Pseudomonas putida is a HTH-type transcriptional repressor that controls expression of the TtgABC efflux pump, which is the main contributor to resistance against several antimicrobials and toxic compounds in this microbe. One of the main strategies to modulate the bacterial resistance is the rational modification of the ligand binding target site. We report the design and characterization of four mutants-TtgRS77A, TtgRE78A, TtgRN110A and TtgRH114A - at the active ligand binding site. The biophysical characterization of the mutants, in the presence and in the absence of different antimicrobials, revealed that TtgRN110A is the variant with highest thermal stability, under any of the experimental conditions tested. EMSA experiments also showed a different dissociation pattern from the operator for TtgRN110A, in the presence of several antimicrobials, making it a key residue in the TtgR protein repression mechanism of the TtgABC efflux pump. We found that TtgRE78A stability is the most affected upon effector binding. We also probe that one mutation at the C-terminal half of helix-α4, TtgRS77A, provokes a severe protein structure distortion, demonstrating the important role of this residue in the overall protein structure and on the ligand binding site. The data provide new information and deepen the understanding of the TtgR-effector binding mechanism and consequently the TtgABC efflux pump regulation mechanism in Pseudomonas putida.This work was supported by Spanish Ministry of Economy and Competitiveness, National programme for Recruitment and Incorporation of Human Resources, Subprogramme: Ramon y Cajal RYC-2009-04570 and grant P11-CVI-7391 from Junta de Andalucía and EFDR (European Regional Development Fund)

Review of health effects of non-ionizing radiations

Non-ionizing radiations (electromagnetic waves) consist of electric and magnetic waves travelling together. In decreasing order of wavelengths, they are classified into ultra long electromagnetic waves, radio waves, micro waves, infrared waves and visible rays. Man-made sources of non-ionizing radiation include electrical, electronic and communication appliances that abound in our homes and offices, while natural sources include the sun and the earth. Electromagnetic radiations in the environment can be measured by use of electromagnetic meters. Radiation exposure standards are regulated based on International Commission on Non-ionizing Radiation Protection (ICNIRP) guidelines. ICNIRP exposure limits for EM radiation for electrical/electronic appliances in homes and electricity transformers is < 1milligauze and 50 hertz respectively. A study, in Nigeria, found that most GSM handsets emit radio frequency radiations with power far above the ICNIRP recommended level of 9W/m2. There are conflicting research reports concerning the safety of non-ionizing radiations. However, reported harmful effects predominate. For example, non-ionizing radiations increase cellular generation of free radicals, disrupt the blood-brain barrier, and decrease cognitive functions of the brain. These result in genotoxic effects, cancer, decreased male fertility, increased allergic and hypersensitivity disorders and diabetes mellitus. Protective measures against excessive non-ionizing radiation absorption include keeping safe distance (at least 1.2m) from all electrical appliances in homes and offices, reducing time spent with them, and avoiding use of cordless equipment. Reported beneficial effects of magnetic therapy include clinical improvement in cases of Alzheimer's disease, arthritis, bronchitis, depression as well as increased healing of fractures. Most of these are attributed to its anti-inflammatory effects. In conclusion, concerns about harmful effects of non-ionizing radiations are real and calls for caution irrespective of reports to the contrary. There is need, therefore, to increase public awareness on the dangers of non-ionizing radiations.Key words: Non-ionizing radiation, harmful effects, magnetotherapy, exposure standards

Toxicity of cholecalciferol overdosage in white albino mice

Background: Irrational prescription and use of vitamins is rife in our society today. Being fat-soluble, vitamin D (cholecalciferol) easily accumulates in the body when the recommended daily allowance is exceeded.  There is need to determine the effect of this vitamin overdosage in animals and possibly extrapolate the findings to human beings. Aim: To determine subacute and chronic toxicity of cholecalciferol overdosage in white albino mice. Methods: Increasing doses of cholecalciferol were given to three groups of white albino mice per ora after acute toxicity test. A fourth group was given normal saline as control. Exposure period was 22 days and 12 weeks for subacute and chronic toxicity tests respectively. Thereafter, serum levels of alkaline phosphate, total calcium and inorganic phosphate as well as histological sections of the liver, kidney and stomach were examined. Data were analyzed and p values < 0.05 considered statistically significant. Results: Acute toxicity test gave LD50 of 9,747 iu/kg. There was statistically significant increase in all parameters examined in all groups of mice when compared with controls (p = 0.0001 for all groups).  Histological sections of organs showed severe degeneration of liver architecture, inflammation of glomerular and tubular regions of the kidney as well as ulceration of the stomach mucosa and submucosa. Conclusion: High doses of vitamin D were toxic to white albino mice.  Further studies are needed to determine the effect on liver and kidney functions by measuring serum transaminases and urea/creatinine respectively. Keywords: Cholecalciferol overdosage, Toxicity tests, Alkaline phosphatase, Histological section

Some Pharmacological Studies Of Aqueous Extract Of Leaves Of Euphorbia Heterophylla

This work was set out to identify the pharmacological basis for the laxative effect of leaves of Euphorbia heterophylla as well as identify its other pharmacological properties: Material/ Methods: Effect of aqueous extract of the leaves was tested on isolated guinea pig ileum and isolated pregnant rat uterus using organ bath and kymograph. Its anticoagulant properties were tested on whole blood. Results: The extract produced statistically significant contractions of isolated guinea pig ileum similar to that produced by histamine and acetylcholine. It also produced statistically significant contraction of pregnant rat uterus comparable to that produced by oxytocin. The contractile responses on the intestine and uterus were blocked by atropine and salbutamol respectively. The extract also exhibited marked anticoagulant activity in vitro. Conclusion: It is suggested that the laxative effect of this extract is as a result of increased peristaltic movements of the intestine. It is also believed that this extract acted as a muscarinic agent in this experiment since its action was blocked by atropine. While it is tempting to conclude that oxytocic effect of the extract is as a result of binding to oxytocin receptors, this cannot be substantiated because salbutamol, which blocked this effect, is a non-specific relaxant of the pregnant uterus. The saponins richly contained in the extract may be responsible for the observed anticoagulant effect Keywords: Euphorbia heterophylla, Laxative Anticoagulant, Abortifacient.Tropical Journal of Medical Research Vol. 10 (2) 2006: pp. 1-