An Air-Gap Enzyme Electrode: Development and Applications

A novel air-gap enzyme electrode was developed by amalgamating the principles controlling ion-selective electrodes, enzyme kinetics, and diffusion of molecules across membranes. Commercially available ammonia and carbon dioxide gas-sensing electrodes were modified to measure the respective gases over a head-space. A plexiglass cell was designed and fabricated to house the modified electrodes. The air-gap electrodes exhibited superior sensitivity and response characteristics compared to the original membrane electrodes. The plexiglass cell was divided into two compartments by virtue of a selectively permeable membrane. Enzymatic reactions were conducted in the cell to determine quantitatively the concentration of the substrate. L-Phenylalanine ammonia lyase was used to determine L-phenylalanine with the ammonia electrode and L-glutamate decarboxylase was utilized for the determination of L-glutamic acid by the carbon dioxide electrode. Near-Nernstian slopes were obtained for the response of the enzyme electrodes. In addition to the good reproducibility, the method provided unique ability to reuse the same enzyme solution for several determinations of various concentrations of the analyte. The performance of the two compartment cell and air-gap enzyme electrode was found to be superior in comparison to conventional enzyme electrodes.     

Pseudoaneurysm: a complication of faulty technique in femoral arterial puncture

Pseudoaneurysm is a well-documented but rare complication of retrograde femoral arterial puncture. We present six patients in whom pseudoaneurysm complicated this procedure. The pseudoaneurysm arose from the superficial femoral artery in five patients and from the profunda femoris artery in one. An arteriovenous fistula also arose from the superficial femoral artery in one patient. In no patient did the pseudoaneurysm arise from the common femoral artery. Two mechanisms are postulated as to why pseudoaneurysms rarely complicate puncture of the common femoral artery.     

Tumour necrosis factor-related apoptosis-inducing ligand is a novel therapeutic target in pulmonary arterial hypertension

BackgroundPulmonary arterial hypertension is a fatal disease characterised by progressive narrowing of pulmonary arterioles, driven by aberrant cellular proliferation. Identification of key pathways in disease pathogenesis is required for the development of new-targeted therapies. We have previously reported tumour necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) immunoreactivity within pulmonary vascular lesions from patients with idiopathic pulmonary arterial hypertension and animal models. Since TRAIL induces endothelial cell apoptosis and smooth muscle cell proliferation, we hypothesised that TRAIL is an important driver of disease in pulmonary arterial hypertension.MethodsWe characterised the expression of TRAIL in human and rodent pulmonary arterial hypertension and determined the effects of TRAIL on pulmonary artery smooth muscle cells (PASMCs) in vitro. Using genetic deletion, pharmacological overexpression, antibody blockade, and bone marrow transplant (BMT) chimera experiments we determined the direct pathogenic role of TRAIL in three independent rodent models of pulmonary arterial hypertension. We then tested the efficacy of inhibiting TRAIL in halting or regressing established disease in two preclinical models. Terminal phenotyping included cardiac catheterisation, echocardiography, and pulmonary vascular immunohistochemistry.FindingsTRAIL mRNA and protein expression was upregulated in PASMCs from patients with pulmonary arterial hypertension. In vitro, TRAIL was a mitogen for PASMCs. TRAIL-deficient mice were protected from both hypoxia-induced and diet-induced pulmonary arterial hypertension. Antibody blockade prevented rats from developing toxin-induced disease. In BMT chimeras, only mice with expression of TRAIL restricted to tissue developed pulmonary arterial hypertension. In rodents with established pulmonary arterial hypertension, an anti-TRAIL antibody reversed pulmonary vascular remodelling, through reducing proliferation and inducing apoptosis, improved pulmonary haemodynamics, and significantly improved survival.InterpretationOur studies are the first to determine the importance of TRAIL in the pathogenesis of pulmonary arterial hypertension and demonstrate its potential for translation into a novel therapeutic targetFundingBritish Heart Foundation.     

A randomized clinical trial to assess the efficacy of intramuscular droperidol for the treatment of acute migraine headache.

In a recent case series, we reported that intramuscular droperidol appeared to be an effective therapy for the treatment of acute migraine headache. The objective of the study was to further assess the efficacy of intramuscular droperidol for the treatment of acute migraine headache. The study design was a randomized, clinical trial set in a community-based ED. The population was a convenience sample of ED patients who met International Headache Society acute migraine criteria. Exclusions included pregnancy, use of narcotic or phenothiazine medications within 24 hours. For the protocol, patients were randomized to 1 of 2 treatment groups. Patients and physicians were blinded as to the treatment provided. Patients recorded their initial pain on a 100mm Visual Analog Scale (VAS) Patients were randomized to receive either 2.5 mg droperidol intramuscularly; the other group received 1.5 mg/kg meperidine intramuscularly. After 30 minutes patients recorded their pain on the VAS and recorded their preference for the medication on a Likert Scale. Physicians recorded the incidence of any side effects and the need for rescue medication. Statistical analysis consisted of categorical variables that were analyzed by chi-square, continuous interval data by t-tests and ordinal data by Mann-Whitney U test. The primary outcome parameters were mean VAS score change and the percentage of patients who wanted to go home without rescue medication. The study had an 80% power to detect a 26 mm difference in the mean change in VAS between groups. Of the 29 patients who were enrolled, 15 received droperidol. Both groups were similar with respect to age (30.7 +/- 8.9 years droperdol v 32.7 +/- 9.9 years meperidine; P =.59), female sex (73% v 71%; P =.91), mean headache duration (24.7 +/- 28.3 v 18.3 +/- 25.8 hours; P =.55). The droperidol group had a higher mean initial VAS score (88 v 76 mm; P =.03). The 2 groups were similar with regard to outcome, including: mean change in VAS score (47 v 37 mm; P =.33), average Likert score (1.1 v 1.9; P =.85), and the percentage of patients who did not want rescue medication (67% v 57%; P =.61). The incidence of sedation was 6.7 v 14.3%. Akathisia occurred in 13.3% of pts who received droperidol. We found that intramuscular droperidol was similar in efficacy to meperidine with a low incidence of side effects.     

Seroprevalence of Neospora spp. in Horses in North East of Iran

Background

Neospora caninum, an obligate intracellular protozoan parasite, is recognized as a major cause of abortion in cattle, while limited information is presently available on the seroprevalence of Neospora antibodies in horses’ worldwide. The aim of the present study was to determine serologic prevalence of Neospora infection in horses in Iran.

Methods

Sera from 150 horses from Mashhad suburb in Razavi Khorasan Province, northeast Iran were examined for antibodies to Neospora spp. using Neospora modified direct agglutination test (N-MAT).

Results

Antibodies to this parasite were detected in 45 (30%) of the examined serum samples. Thirty four percent of the samples had titer of 1:40 while then reduced to 30% when 1:80 serum dilution was applied as significant cut off titer.

Conclusion

This study is the first investigation carried out on the Neospora in horses in Iran and indicates that horses in Iran are exposed to this parasite.     

A posterior open bite

A case of bilateral posterior open bite, treated using the 'straight wire' appliance, is reported. The diagnostic problems, associated with this type of malocclusion, are discussed.     

Minor Head Trauma in Anticoagulated Patients

OBJECTIVE: To determine the incidence of clinically significant intracranial injury in the anticoagulated patient suffering minor head trauma without loss of consciousness (LOC) or acute neurologic abnormality. METHODS: A retrospective chart review was performed based on a computerized search of electronic patient records from six community hospital EDs, one of which is a trauma center. Patients taking warfarin who sustained minor head trauma without LOC having no acute neurologic abnormalities treated from January 1994 to January 1996 were identified using a search of electronic ED records. Charts were reviewed for mechanism of injury, physical examination findings of head injury, and concomitant injury. Prothrombin time and head CT results were recorded if obtained. For those patients not receiving a head CT on ED evaluation, telephone follow-up was performed to determine outcome. RESULTS: There were 65 patients meeting inclusion criteria. Thirty-eight patients had prothrombin times obtained, with ranges from 12.0 sec to 30.7 sec. There was no intracranial injury found in any of the 39 patients having a head CT. Additionally, follow-up on the 26 patients who did not undergo CT scanning revealed no evidence of complications related to their head injuries. CONCLUSIONS: The incidence of clinically significant intracranial injury is extremely low in the anticoagulated patient suffering minor blunt head trauma without LOC or acute neurologic abnormality. CT scanning may not be necessary in these patients. Larger prospective studies are needed to confirm these findings.