Use of the gel-based DiaMed-ID microtyping system for crossmatching enhances sensitivity

A host of newer techniques have been introduced over the past decade in blood bank serological testing. One such technology which has been in vogue in the west since early 1990s is the gel test. The procedures used are standardized and they provide clear and stable reactions that improve result interpretation. The principle involves the differential passage of red cell agglutinates and free red blood cells through a dextran acrylamide gel. The results are stable and may be read even after many hours. The test is easy to perform, sensitive and reproducible. We report our experience in compatibility testing with use of the DiaMed micro typing system which is based on the gel technology. Over a one year period since this technology was introduced in our blood bank, we noticed a startling 65 fold rise (p<0.0001) in the reported number of incompatible units in one year which rose from a paltry 4 (0.02%) to 260 (1.6%). We found the DiaMed system easy to use and as our findings suggest it proved to be more sensitive than the conventional tube agglutination technique.     

Ophthalmoplegia in an adult with chronic inflammatory demyelinating polyradiculoneuropathy

The authors present a 75-year-old patient with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) and ophthalmoplegia. The patient had recurrent exacerbations and remissions of her polyneuropathy over the course of one year. Antibodies to ganglioside GM-I were not detected. Ophthalmoplegia in CIDP is uncommon, but is reported to occur in 3-8% of patients. Ophthalmologists should be aware of the association of CIDP and ophthalmoplegia.     

Comparative evaluation of various diagnostic techniques for detection of Cryptosporidium infection from the faecal samples of diarrhoeic bovine calves

Background: Cryptosporidium, an opportunistic, zoonotic, apicomplexan parasite, is one of the most common causes of diarrhea in neonatal bovine calves around the globe. Bovine calves act as a major source of infection by excreting huge numbers of highly resistant oocysts in faeces, which can survive for a long time in extreme environmental conditions. As low as ten oocysts can cause disease and mortality, leading to the requirement of an early and accurate diagnosis for proper and favorable prognosis, management, and control. Aims:The current study was conducted with the objective to evaluate various diagnostic techniques (acid fast staining, negative staining, fluorescent, ELISA, PCR, nested PCR, and qPCR) for the detection of Cryptosporidium in the faecal samples of diarrheic bovine calves. Methods:Two hundred diarrheic faecal samples from bovine calves were collected and subjected to these techniques for Cryptosporidium diagnosis. Results of these were evaluated for diagnostic comparison. Results:Out of 200 faecal samples evaluated, 24% (48/200) were detected positive for Cryptosporidium using a combination of two techniques as gold standard criteria. Cohen’s kappa value indicated moderate to almost perfect agreement (0.616 to 0.986) among all the techniques used in the present study. Leishman staining showed the lowest sensitivity (54.17%), while nested PCR and qPCR showed the highest sensitivity (97.92%). Diagnostic specificity of all these tests ranged from 98.68 to 100%. Conclusion:Auramine stain was used for the first time in the bovine calves in India for the detection and diagnostic comparison of Cryptosporidium. It showed strong agreement with the molecular as well as classical diagnostic techniques, and can be used for primary screening for better diagnosis.Key Words: Cryptosporidium, Diagnostic accuracy, ELISA, Fluorescence, PCR     

Increased fetoplacental active renin production in pregnancy-induced hypertension

Since pregnancy-induced hypertension is associated with impaired uteroplacental blood flow, we studied fetoplacental and maternal renin production in controls and subjects with pregnancy-induced hypertension. We measured total, active, and inactive (pro-) renin in maternal serum, fetal arterial and venous blood, and chorion homogenate in eight normotensive term patients and 18 patients with pregnancy-induced hypertension. No differences in active or prorenin were found in maternal blood from normal women or patients with pregnancy-induced hypertension. In contrast, fetal artery and vein, as well as chorionic tissue, contained significantly higher active renin in pregnancy-induced hypertension compared with normal subjects. No difference in fetal or chorionic prorenin was seen in the two groups. Thus active to total renin ratio was higher in the fetus and chorion of subjects with pregnancy-induced hypertension, which suggests enhanced active renin production. These results suggest that pregnancy-induced hypertension is associated with increased activity of the renin-angiotensin system in the fetoplacental unit, which is not reflected in the maternal circulation. This may be an attempt by the fetus and chorionic membranes to maintain vascular homeostasis in the face of altered uteroplacental blood flow.     

The antihypertensive chromogranin a peptide catestatin acts as a novel endocrine/paracrine modulator of cardiac inotropism and lusitropism

Circulating levels of catestatin (Cts; human chromogranin A352-372) decrease in the plasma of patients with essential hypertension. Genetic ablation of the chromogranin A (Chga) gene in mice increases blood pressure and pretreatment of Chga-null mice with Cts prevents blood pressure elevation, indicating a direct role of Cts in preventing hypertension. This notable vasoreactivity prompted us to test the direct cardiovascular effects and mechanisms of action of wild-type (WT) Cts and naturally occurring human variants (G364S-Cts and P370L-Cts) on myocardial and coronary functions. The direct cardiovascular actions of WT-Cts and human variants were determined using the Langendorff-perfused rat heart. WT-Cts dose-dependently increased heart rate and coronary pressure and decreased left ventricular pressure, rate pressure product and both positive and negative LVdP/dt. WT-Cts not only inhibited phospholamban phosphorylation, but also the inotropic and lusitropic effects of WT-Cts were abolished by chemical inhibition of beta2-adrenergic receptors, Gi/o protein, nitric oxide or cGMP, indicating involvement of beta2-adrenergic receptors-Gi/o protein-nitric oxide-cGMP signaling mechanisms. In contrast, G364S-Cts did not affect basal cardiac performance but abolished isoproterenol-induced positive inotropism and lusitropism. P370L-Cts decreased rate pressure product and inhibited only isoproterenol-induced positive inotropism and lusitropism by 70%. Cts also inhibited endothelin-1-induced positive inotropism and coronary constriction. Taken together, the cardioinhibitory influence exerted on basal mechanical performance and the counterregulatory action against beta-adrenergic and endothelin-1 stimulations point to Cts as a novel cardiac modulator, able to protect the heart against excessive sympathochromaffin overactivation, e.g. hypertensive cardiomyopathy.     

Ventricular fibrillation in a left ventricular assist device patient: Can the echocardiogram be misleading?

Sustained ventricular tachycardia and ventricular fibrillation (VF) are life-threatening arrhythmias which remain highly prevalent in patients with advanced heart failure. These ventricular arrhythmias may impair the support provided by continuous-flow left ventricular assist devices (CF-LVADs) and lead to frequent hospitalizations, antiarrhythmic medication use, external defibrillations, and need for heart transplantation. We report a case in which a patient with a CF-LVAD and an implantable cardioverter defibrillator at end of life presented with asymptomatic low-flow alarms and was found to have VF of unknown duration. Unique in our case was the presence of apparent organized contractility and rhythmic opening of the mitral valve on echocardiogram despite VF on electrocardiogram.