Titrimetric determination of ascorbic acid using chloranil

Ascorbic acid is oxidized and quantitatively titrated with chloranil (2,3,5,6-tetrachloro-1,4-benzoquinone) in the presence of hexamethylenetetramine in acetone-water; the end point is determined visually by the appearance of a golden yellow color. Colored solutions are assayed by setting the initial absorbance at 451 nm to zero or the minimum, titrating with chloranil solution, and measuring absorbance after each increment of titrant. A plot of the volume of chloranil added against the absorbance gives a straight line with the volume intercept as the end point. Interference by the thiol group of cysteine, glutathione, etc., is avoided by masking with acrylamide; interference by iron(II) is masked with ammonium thiocyanate and sodium potassium tartrate. Hydrogen sulfite and thiourea (which do not interfere) are added as antioxidants during extraction of ascorbic acid from drugs and fruits.

Intracavitary thrombi in the right heart associated with multiple pulmonary emboli. Report of two patients

Two-dimensional echocardiography identified intracavitary masses in the right heart in two patients presenting with extensive pulmonary embolism. In one, a right ventricular mass was identified which was confirmed at subsequent autopsy to be an organizing thromboembolus. In the second patient, a right atrial mass was identified; it disappeared with thrombolytic therapy which was accompanied by clinical improvement. We demonstrate that intracardiac thrombi associated with pulmonary embolism may be identified noninvasively by two-dimensional echocardiography. We suggest the presence of thrombi may represent a large intravascular thrombus. This recognition may influence therapeutic decisions.

Causes of perioperative myocardial infarction: their identification and prevention

Despite major technical advances in coronary bypass surgery and myocardial preservation, perioperative infarction remains a serious problem. The authors review the pathogenesis of the two different types of myocardial injury, occlusion necrosis and reperfusion necrosis. These two entities can be distinguished clinically by radioisotope scanning. Experimental studies have demonstrated that reperfusion necrosis can be prevented pharmacologically. Since the majority of perioperative infarcts are probably due to reperfusion, the importance of distinguishing between these two entities is evident.

Effect of naproxen on the kinetics of elimination and anticoagulant activity of a single dose or warfarin

The purpose of this investigation was to determine the effect of the nonsteroidal anti-inflammatory drug naproxen on the elimination kinetics and anticoagulant activity of warfarin. Ten healthy men received one oral dose of 50 mg racemic warfarin alone and with naproxen, 375 mg twice daily for 17 days beginning 10 days before warfarin. Naproxen administration caused a small but statistically significant increase in the free fraction of warfarin in serum but had no significant effect on the total clearance, volume of distribution, half-life, and anticoagulant activity of warfarin. Warfarin, on the other hand, apparently enhances the serum protein binding of haproxen. There was substantial intersubject variation but very little intrasubject variation in the anticoagulant effect of warfarin. The intersubject variation of the anticoagulant effect was not related to the elimination kinetics of warfarin.

Effect of naproxen on the steady-state serum concentration and anticoagulant activity of warfarin

The purpose of this investigation was to determine whether the anti-inflammatory drug naproxen interacts with warfarin during prolonged administration of both drugs. Healthy adults received oral doses of warfarin daily for 26 days. Naproxen, 375 mg twice daily, was given from the eleventh through the twentieth days. Naproxen administration had no apparent effect on the steady-state concentrations of free and total (free and protein-bound) warfarin in serum, despite a small but statistically significant increase of the warfarin-free fraction in serum. There was no apparent difference between the prothrombin times (at a constant daily dose of warfarin) observed before, during, and after administration of naproxen.

Speckle reduction using multiple tones of illumination

The occurrence and smoothing of speckle are studied as a function of the line width for a highly collimated illuminating source. A general theory is presented for speckling in the image of a partially diffuse, phase type of object, which has a variable number of random scattering centers per resolution element. Then, an expression is derived for the wavelength spacing required to decouple the speckle patterns arising from two monochromatic tones in an imaging system, thereby establishing that it is feasible to smooth speckle using multicolor illumination. This theory is verified in a series of experiments using both laser illumination and band-limited light from a carbon arc. With highly collimated sources, we show that speckle appears laserlike for an imaged diffuser even up to line widths of 5 A. Then, smoothing of speckle is demonstrated in the imaging of a diffuser and for a section of an optic nerve when the illumination is provided by six narrow lines spread over 1500 A. Since with color-blind, panchromatic viewing the speckle smooths, a direct extension of this method to holographic microscopy, using a multitone laser, should permit one to record and reconstruct holograms of diffraction-limited resolution that are essentially speckle-free.

Evaluation of management, control, complications and psychosocial aspects of diabetics in Bangladesh: DiabCare Bangladesh 2008

DiabCare Bangladesh 2008 evaluated the current status of diabetes care in Bangladesh as a continuation of similar cross-sectional study conducted previously in 1998. The current study recruited 1952 patients from general hospitals, diabetes clinics and referral clinics to study current scenario of diabetes management from 01 March 2009 to 31 March 2009. We report the results of type 2 diabetic population who constituted 95.3% (n=1860). Results showed deteriorating glycaemic control with mean HbA1c of 8.6±2.0% with only 23.1% of the patients achieving American Diabetes Association (ADA) target of <7%. 896 (47.0%) patients were hypertensive and 850 (94.9%) were on antihypertensive medication. 70.8% of patients had LDL levels >2.6 mmol/L; 43.8% had triglycerides >2.2 mmol/L; 44.1% had HDL<1 mmol/L despite 48% of the patients being on lipid lowering agents. Microvascular, macrovascular and severe late complications were reported in 39.2%, 9.9% and 12.1% patients respectively. The rates of diabetic complications were cataract 12.9%, microalbuminuria 15.7%, neuropathy symptoms 31.7%, leg amputation 1.2% and history of angina pectoris was 6.6%. Quality of life evaluation showed that about half of patients have poor quality of life. Also, there was poor adherence to diet, exercise and self testing of blood glucose. In conclusion, majority of the patients were still not satisfactorily controlled. There is an urgent need for effective remedial measures to increase adherence to practice guidelines and to educate both patients and healthcare personnel on importance of achieving clinical targets for metabolic control. DOI:  http://dx.doi.org/10.3329/bmrcb.v37i1.7793 Bangladesh Med Res Counc Bull 2011; 37: 11 - 16