Accuracy of three electronic apex locators in determining the apical foramen in multi‐rooted teeth: Randomised clinical and laboratory study

This study aimed to compare the accuracy of three electronic apex locators (EALs), Raypex 5, Apex NRG and ProPex II, in locating the apical foramen (AF) in vivo. Thirty multi‐rooted teeth were included in the study. Distances from the file tip to the radiographic apex from the buccal (R1) and mesial (R2) aspect were measured after extraction. The distance from the file tip to the AF (L) was measured microscopically. Raypex 5, Apex NRG and ProPex II were accurate to within ± 0.5 mm in 84.6%, 78.6% and 66.7% of cases, respectively. R1, R2 and L measurements between the EALs were not statistically different (P > 0.05). R1 and L correlated positively (r² = 0.817; P < 0.001). There were no significant differences in all measurements between vital and non‐vital root canals (P > 0.05). There was no statistically significant difference between the EALs. There was a positive correlation between electronic and radiographic measurements when locating the AF.     

Hemoglobin M equon beta 41 (C7) phenylalanine leads to tyrosine

A severe hemolytic crisis was observed in a 34-yr-old female of English- Irish extraction following a viral illness treated with acetaminophen. Heinz bodies and heat instability were present only during a transient hemolytic event. A challenge dose of acetaminophen caused no detectable hematologic abnormality. Structural studies of the hemoglobin during hemolysis and again after complete recovery localized the abnormality to tryptic peptide beta Tp-5, and automated sequencing of I 125-labeled beta chains indicated a replacement of phenylalanine (C7) beta 41 by tyrosine. Substitution of the next residue, phenylalanine (CD1) beta 42 by serine (Hb Hammersmith), has resulted in chronic severe Heinz body hemolytic anemia. The lack of chronic anemia in the present disorder may reflect the different relationships of beta41 and beta 42 and/or the similarities in volume and hydrophobicity of tyrosine and phenylalanine. It is suggested that substitution of tyrosine for phenylalanine in Hb Mequon may disturb the critical environment around the heme group and render it susceptible to oxidative denaturation in the presence of infections and/or drugs.     

Vav proteins control MyD88-dependent oxidative burst

The importance of reactive oxygen intermediate (ROI) production in antimicrobial responses is demonstrated in human patients who suffer from chronic granulomatous disease (CGD) due to defective NADPH oxidase function. Exactly how bacterial products activating Toll-like receptors (TLRs) induce oxidative burst is unknown. Here, we identify the Vav family of Rho guanine nucleotide exchange factors (GEFs) as critical mediators of LPS-induced MyD88-dependent activation of Rac2, NADPH oxidase, and ROI production using mice deficient in Vav1, Vav2, and Vav3. Vav proteins are also required for p38 MAPK activation and for normal regulation of proinflammatory cytokine production, but not for other MyD88-controlled effector pathways such as those involving JNK, COX2, or iNOS and the production of reactive nitrogen intermediates (RNIs). Thus, our data indicate that Vav specifically transduces a subset of signals emanating from MyD88.     

Loose ligation of the sciatic nerve is associated with TrkB receptor-dependent decreases in KCC2 protein levels in the ipsilateral spinal dorsal horn

Significant decreases in the protein levels of potassium-chloride co-transporter 2 (KCC2) were detected in the ipsilateral spinal dorsal horn 4 h following loose ligation of the sciatic nerve. These decreases were associated with a change in hindlimb weight distribution suggestive of pain behavior. In contrast, no changes in GABA-A receptor subunit alpha-1 levels were detected. The decreases in KCC2 coincided with a significant ipsilateral increase in BDNF protein levels. Both the decreases in KCC2 levels and the early pain behavior were prevented by intrathecal pre-treatment with the BDNF-sequestering TrkB/Fc chimera protein or the tyrosine kinase blocker K252a. The ligation-associated decreases in KCC2 levels were transient. In the ipsilateral spinal dorsal horn of ligated animals exhibiting weight-bearing pain behavior 7 days after the ligation the KCC2 levels were identical to those in control or sham-operated animals. These data suggested that TrkB-dependent reduction in KCC2 protein levels in the spinal dorsal horn was an early consequence of peripheral nerve injury. This decrease in KCC2 may have elicited an early increase in overall dorsal horn neuronal excitability perhaps through a loss of GABA inhibition which is critically dependent on KCC2 activity. The increased neuronal excitability may in turn have caused enhanced and exaggerated communication between primary afferents and dorsal horn neurons to contribute to the early behavioral signs of pain.     

Blood Transfusion Practices in Military Medicine

Background

This observational study was conducted in a small, 45 bed border static hospital, located in a field area, where no blood bank facilities were available. The present study was conducted to elucidate the blood transfusion practices of this hospital. Methods: A retrospective analysis of all blood transfusions performed in this hospital between Dec 2004 and Dec 2006 was carried out. The data collection included blood group patterns, common indications, haemoglobin levels and complications of blood transfusion. Inferences were based on available data and relevant statistical analysis.

Result

A total of 246 blood transfusions were administered to 79 recipients during the study period. Only one patient had an Rh negative blood group. The most frequently transfused blood group was A Rh positive. Majority of transfusions were administered to surgical cases and the commonest indication was gunshot wounds with haemorrhagic shock. The mean haemoglobin at admission was 8.93 g/dl. The mean number of blood transfusions per patient was 3.13. No haemolytic or other transfusion reactions occurred in any of the transfusions.

Conclusion

This study demonstrates that blood transfusions can be safely administered in field conditions despite constraints of not having a blood bank.Key Words: Blood transfusion practices, Haemoglobin, Anaemia