Rizatriptan in the treatment of migraine

Migraine is a common, disabling disorder associated with considerable personal and societal burden. Current guidelines recommend triptans for the acute treatment of migraine unlikely to respond to less effective therapies. Rizatriptan is a second-generation triptan available in tablet or orally disintegrating tablet (wafer) formulations that offers several advantages over other members of its class. Rizatriptan is rapidly absorbed from the gastrointestinal tract and achieves maximum plasma concentrations more quickly than other triptans, providing rapid pain relief. Clinical trials have shown that rizatriptan is at least as effective or superior to other oral migraine-specific agents in the acute treatment of migraine, and has more consistent long-term efficacy across multiple migraine attacks. Rizatriptan has a favorable tolerability profile, and patients have reported greater satisfaction and a preference for rizatriptan over other migraine-specific agents. Improvements in quality of life reported with rizatriptan are consistent with its favorable efficacy and tolerability profiles. Notably, multi-attribute decision models that combine clinical data with patient- and physician-reported treatment preferences have identified rizatriptan as one of three triptans closest to a hypothetical “ideal”. The efficacy and tolerability of rizatriptan for the acute treatment of migraine have thus been well established.     

The Encapsulation of Squid Diisopropylphosphorofluoridate-Hydrolyzing Enzyme within Mouse Erythrocytes

This study describes the entrapment of squid-type diisopropylphosphorofluoridate-hydrolyzingenzyme (DFPase) within mouse red blood cells. These erythrocytesthereby gain the ability to rapidly hydrolyze alkylphosphatecholinesterase (ChE) inhibitors such as diisopropyl fluorophosphate(DFP). DFPase rapidly hydrolyzes DFP to diisopropyl phosphate.Resealed erythrocytes provide a stable carrier system that canpreserve the activity of encapsulated enzymes against otherwiserapid in vivo degradation; thus, ChE inhibitors can be degradedto relatively nontoxic metabolites by these erythrocyte carriers.Squid DFPase was purified from the hepatopancreas of Atlanticsquid and DFPase activity was determined by measuring changesin fluoride ion concentration using a fluoride ion selectiveelectrode. Mouse erythrocytes in suspension with excess squidDFPase were dialyzed against hypotonic buffer to allow the encapsulationof the enzyme to occur. Cells were then resealed by returningthe suspension to isosmotic with saline. Rate of DFP hydrolysisobserved with these cells was much greater than the rate ofnonenzymatic hydrolysis and was directly proportional to theamount of the erythrocyte suspension added to the assay solution.The rate of hydrolysis was first order in substrate. Erythrocytecontrols showed no endogenous DFPase activity. These resultssuggest that enzyme entrapment may be developed as a methodto prevent and antagonize organophosphate poisoning.     

Case Report: Giant choledochal cyst

We report an adult female with a rare giant choledochal cyst. The patient presented following a normal pregnancy with the classical triad of an abdominal mass associated with jaundice and right upper quadrant abdominal pain. The cyst was excised using an intramural technique and biliary reconstruction achieved with a Roux-en-Y hepaticojejunostomy. Our patient has remained well with no evidence of malignancy over a 12 year review period. The aetiology and current management of this condition are discussed.     

Age as a Major Factor Affecting Adherence to Medication for Hypertension in a General Practice Population

Weingarten M A and Cannon B S. Age as a major factor affectingadherence to medication for hypertension in a general practicepopulation. Family Practice 1988; 5: 294–296. An audit of the treatment of hypertension in a general practicerevealed that 51 out of 246 patients prescribed medication didnot collect their monthly supply of drugs. There were no significantdifferences between the adherers and the non-adherers in sex,severity of hypertension, type or complexity of medication.The patient's age was the only factor which was associated withadherence. Patients under the age of 55 years or over 65 yearshad significantly lower adherence than those aged 55–64years. Most previous studies coming from hospital-based or clinicaltrial populations have failed to demonstrate this associationwith age which may be characteristic of an unselected generalpractice population. The results may not be applicable to populationsof different social or cultural background but they suggestappropriate directions for health promotion efforts in our community.     

EFFECTS OF INCREASED CARDIAC OUTPUT ON PULMONARY BLOOD FLOW DISTRIBUTION DURING LOBAR VENTILATION HYPOXIA AND COLLAPSE

Electromagnetic flow probes were placed around the pulmonaryartery and left lower lobe artery in anaesthetized open-chestdogs in order to measure possible changes in the ratio of lobar-to-totalpulmonary blood flow (l/t) in response to changes in cardiacoutput produced by the opening of arterio-venous fistulae orfluid loading. Ventilation of the lobe with 7% oxygen or lobarcollapse reduced l/t by 35% and 42%, respectively, butthere were no significant changes in l/t in response to increases in t of 29–133%. It is concludedthat the changes in t, pulmonary vascular pressures and mixed venous PO₂ within the range studieddid not influence l/t.     

Determination of optimal cryoprotectants and procedures for their addition and removal from human spermatozoa

The objective was to test the hypothesis that the optimal cryoprotective agent for cryopreservation of human spermatozoa would be a solute for which cells have the highest plasma membrane permeability, resulting in the least amount of volume excursion during its addition and removal. To test this hypothesis, theoretical simulations were performed using membrane permeability coefficients to predict optimal procedures for the addition and removal of a cryoprotectant. Simulations were performed using data from four different cryoprotectants: (i) glycerol, (ii) dimethyl sulphoxide, (iii) propylene glycol and (iv) ethylene glycol. Thermodynamic formulations were applied to determine approaches for the addition and removal of 1 M and 2 M final concentrations of cryoprotectant, allowing the spermatozoa to maintain a cell volume within their osmotic tolerance limits. Based on these data, ethylene glycol was predicted to be optimal for minimizing volume excursions among the solutes evaluated. These predictions were then experimentally tested using glycerol as the control cryoprotectant and ethylene glycol as the experimental cryoprotectant. The results indicate that there was a higher (P < 0.05) recovery of motile spermatozoa after cryopreservation when using 1 M ethylene glycol than with 1 M glycerol, supporting the hypothesis that use of the cryoprotectant for which the cell has the highest permeability will result in higher cell survival.      

Comparison of isolation of Haemophilus vaginalis (Corynebacterium vaginale) from peptone-starch-dextrose agar and Columbia colistin-nalidoxic acid agar.

A total of 447 cervical or vaginal specimens were inoculated in parallel onto peptone-starch-dextrose (PSD) and Columbia colistin (10 mg/ml)-nalidixic acid (15 mug/ml) (CNA) agar and were incubated for 48 h at 35 degrees C in an atmosphere with 2 to 10% CO2. One hundred (22.4%) of the cultures were positive for Haemophilus vaginalis. Forty-eight of the isolates were recovered from both PSD and Columbia CNA agar, five from PSD only, and 47 from Columbia CNA agar only (P less than 0.001). On Columbia CNA agar, 76 of the isolates were detected after 24 h of incubation, and the remainder were detected within 4 days of incubation.