Artemisinins target the SERCA of Plasmodium falciparum.

Artemisinins are extracted from sweet wormwood (Artemisia annua) and are the most potent antimalarials available, rapidly killing all asexual stages of Plasmodium falciparum. Artemisinins are sesquiterpene lactones widely used to treat multidrug-resistant malaria, a disease that annually claims 1 million lives. Despite extensive clinical and laboratory experience their molecular target is not yet identified. Activated artemisinins form adducts with a variety of biological macromolecules, including haem, translationally controlled tumour protein (TCTP) and other higher-molecular-weight proteins. Here we show that artemisinins, but not quinine or chloroquine, inhibit the SERCA orthologue (PfATP6) of Plasmodium falciparum in Xenopus oocytes with similar potency to thapsigargin (another sesquiterpene lactone and highly specific SERCA inhibitor). As predicted, thapsigargin also antagonizes the parasiticidal activity of artemisinin. Desoxyartemisinin lacks an endoperoxide bridge and is ineffective both as an inhibitor of PfATP6 and as an antimalarial. Chelation of iron by desferrioxamine abrogates the antiparasitic activity of artemisinins and correspondingly attenuates inhibition of PfATP6. Imaging of parasites with BODIPY-thapsigargin labels the cytosolic compartment and is competed by artemisinin. Fluorescent artemisinin labels parasites similarly and irreversibly in an Fe2+-dependent manner. These data provide compelling evidence that artemisinins act by inhibiting PfATP6 outside the food vacuole after activation by iron.

Drinking location and risk of alcohol-impaired driving among high school seniors.

This study investigated environmental predictors of teenagers' alcohol-impaired driving, such as drinking location and alcohol source. Data for this study were part of the 15 Communities Mobilizing for Change on Alcohol Project. Relationships between drinking-driver status, alcohol source, drinking location, alcohol consumption, and individual demographics were determined for the full sample as well as for males and females separately, using mixed-model, logistic regression. Analyses were restricted to high school seniors who were drivers and who consumed alcohol within the last 30 days (N = 1,914). For males and females, the risk of alcohol-impaired driving rose significantly with increases in both the number of binge-drinking events and estimates of the number of drinks required to impair their driving. Drinking location was important in that students who drank outdoors or in a moving car or truck were at significant risk for drinking-driving. Drinking-driving risks specific to females were number of drinking occasions and drinking at someone else's house. Strategies to prevent drinking-driving among teenagers need to consider drinking patterns as well as drinking locations for both males and females.

Ureteric stenting for repair of accidental ureteric injuries.

Intra-operative injury to the ureter is a well known but fortunately uncommon complication of any major pelvic surgical procedure. If recognised on table, it can be repaired by either a substitution ureteroplasty or end-to-end anatomical repair depending upon the extent of tissue loss. Either of these anastomoses could be secured by total internal stent placement. We describe an improvised technique of intra-operative open ureteric stenting particularly when radiological assistance is not available, i.e. during emergency situations.

Outcome of elective prostatectomy.

OBJECTIVES: To determine the symptomatic and urodynamic outcome of elective prostatectomy and to establish whether the outcome is influenced or can be predicted by preoperative urodynamic measurements. DESIGN: Prospective non-randomised study with follow up at a mean of 11 months after operation. Most men were assessed jointly by a urologist and a general practitioner. SETTING: Department of urology in a teaching hospital serving a large district population. PATIENTS: 253 Men listed for elective prostatectomy because of symptoms and low urinary flow rates (less than 15 ml/s) and excluding those already on a waiting list or with acute urinary retention, clinically apparent prostatic cancer, and neurological or cerebrovascular disease; 217 (86%) were followed up. INTERVENTION: Elective prostatectomy. MAIN OUTCOME MEASURE: Classification on the basis of relief of symptoms assessed by patients and urologist and general practitioner and of symptom scores obtained by questionnaire. RESULTS: Of the 217 men followed up, 171 (79%) had a satisfactory subjective review and 155 (72%) had a satisfactory review and also low symptom scores. An unsatisfactory outcome was associated with preoperative symptoms of urge incontinence, small prostatic size and resected weight, low voiding pressures, and low urethral resistance. Preoperative maximum urinary flow rates did not predict outcome. Men with poor outcome could be classified into two groups: those with irritative symptoms who were more likely before operation to have had urge incontinence and detrusor instability and men with symptoms of poor urinary flow who were more likely before operation to have had a small prostate, low voiding pressures, and low urethral resistance. In patients in the second group flow rates or voiding pressures improved little after operation. Men with stable detrusors and either low urethral resistance or low voiding pressures were less likely to do well after prostatectomy, but despite these associations preoperative urodynamic measurements were unable to predict outcome accurately. CONCLUSIONS: Prostatectomy was satisfactory in relieving symptoms and improving urodynamic measurements in most men, but even in those with classic symptoms and low urinary flow rates a substantial minority experienced little improvement afterwards and urodynamic measurements did not accurately predict outcome in individual patients.

Vasography in urethral stricture: novel application of an old technique.

Urethral stricture disease in men has traditionally been investigated with ascending and voiding cystourethrography as well as urethroscopy. The main emphasis during the preoperative assessment is on establishing the exact extent of the disease process in order to plan appropriate management. We describe a technique that represents a novel approach to the assessment of proximal urethral stricture and in selected cases would be of immense help in defining its precise nature and planning definitive treatment.

Shades of greener grass.

Neither system or culture is perfect; a blend just might be. I can't say that one is definitely better, only different. Many Canadian doctors have emigrated only to return within a year or two, frustrated with a market-driven health care system and a much more eclectic and individualistic society. Yes, family physicians can earn more money here and have better access to diagnostics and treatment. But that has to be balanced with a larger bureaucracy and-at least on the surface-less freedom to access those resources. With time and the ubiquitous fiscal imperative, both countries could emerge from their respective crises at similar destinations, but by separate paths. Traveling and particularly working in another culture has been a positive experience for our family. It might not be for everyone. Each physician, with his or her family, must weigh the pros and cons of such a decision. To boldly go where you've never been before, to move or not to move: that is the question.

Obstetrical epidural anaesthesia in a rural Canadian hospital.

Few rural hospitals offer obstetric epidural analgesia services and of those that do, there is a paucity of information about these anaesthetics. A retrospective review was conducted of all obstetrical epidurals from 1984-1988 in an 85-bed hospital in Saskatchewan to examine the indications, complications, and infant outcomes. During that period there were 1224 deliveries. From a total of 915 vaginal deliveries, 42 (4.6%) received an epidural. Caesarean sections numbered 309: 183 (59.3%) were with epidural analgesia of which 69 were urgent and 114 elective. The overall complication rate was 23% with the most important being hypotension (12%), dural punctures (1.8%), inadequate block requiring an intravenous supplement (4.0%) or a general anaesthetic (3.1%). Infant outcomes were favourable except for two unrelated intra-uterine deaths preceding labour.

Clean intermittent self-catheterisation in 172 adults.

We report the results of clean intermittent self-catheterisation (CISC) in 172 adults (68 male, 104 female). Seven patients were unable or unwilling to master the technique and 145 still remain on CISC, representing a total experience of 6981 patient-months. Ten patients required readmission: 5 for retraining and 5 for complications (average hospital stay 2.4 days); 123/163 patients catheterised themselves every 3 to 4 h and 92 were continent on CISC; of the 107 patients incontinent prior to starting CISC, 101 were improved; 70 patients had no infections whilst on CISC, the mean infection rate being 1 per 14 patient-months; 29% of patients experienced persistent urethral bleeding; 156/163 patients were satisfied or very satisfied with CISC and 140 found the technique easy or very easy; 76 patients had never visited their GP for a urinary problem whilst using CISC and the mean rate was 1 visit per 8 patient-months. CISC is an easily learnt technique that is safe and acceptable to patients, and one which places few extra burdens on hospital or community resources.

Ambulatory monitoring and electronic measurement of urinary leakage in the diagnosis of detrusor instability and incontinence.

The ability of conventional artificial filling urodynamic studies (CMG) and ambulatory monitoring during natural bladder filling (AM) to detect phasic detrusor activity (detrusor instability) and incontinence was studied in 52 patients suspected on clinical grounds of having bladder dysfunction, but in whom a CMG had not provided an adequate explanation of their symptoms. Detrusor instability (DI) was found on AM in 31 patients who were not unstable on conventional CMG using the criteria of the International Continence Society: DI was diagnosed on filling in 20 patients and on provocation in a further 11. Incontinence was demonstrated by electronic nappy testing in 23 patients: 13 had urge incontinence due to DI, 7 had genuine stress incontinence alone and 3 had both genuine stress incontinence and detrusor instability. Thus DI was diagnosed significantly more frequently by AM than by CMG. Ambulatory monitoring was more sensitive in the diagnosis of instability and incontinence and it may prove to be a valuable aid in the diagnosis of bladder dysfunction not detected during conventional cystometry.

Urodynamic study of ileocystoplasty in the treatment of idiopathic detrusor instability.

Enterocystoplasty is being used with increasing frequency in the treatment of patients with idiopathic detrusor instability. We have performed a prospective clinical and urodynamic study of this procedure in 11 patients using both conventional (CMG) and ambulatory monitoring techniques (AM). Nine of 11 patients were satisfied with the symptomatic outcome, but 7 relied on clean intermittent self-catheterisation (CISC) to achieve a good result. Urodynamic studies demonstrated a significant increase in residual urine volume from 48 +/- 72 ml before to 347 +/- 298 ml after operation, but there was only a small and statistically insignificant increase in cystometric capacity. Detrusor instability, present before operation in all patients, could still be demonstrated in over half of them after operation. However, a significant decrease in the severity of instability was found after operation as assessed by an increased volume at first unstable contraction. The bladder volume before operation at which the first unstable contraction occurred was smaller in those who still had persistent instability after enterocystoplasty compared with those in whom instability could not be identified after operation. These results suggest that all patients about to undergo ileocystoplasty should be trained in the use of CISC. In selected patients with idiopathic detrusor instability refractory to other treatment, this procedure can yield satisfactory results.

Gap-junctional communication in mouse cumulus-oocyte complexes: implications for the mechanism of meiotic maturation.

The mechanisms underlying the hormonal stimulation of meiotic maturation are not understood. The most prevalent hypothesis is that hormone-induced maturation is stimulated by an increase in the intracellular messengers, cAMP or Ca2+. This study investigated whether Ca2+ transients in somatic cells can lead to Ca2+ transients in the oocyte, and whether hormones that stimulate meiotic maturation of mouse oocytes in vitro and in vivo stimulate an increase in intracellular Ca2+. Of a range of potential agonists of Ca2+ release, ATP and UTP were the only agents that stimulated Ca2+ release in cumulus cells. ATP-induced Ca2+ release is from intracellular stores, as the response is not blocked by chelation of extracellular Ca2+, but is inhibited by the Ca2+-ATPase inhibitor, thapsigargin. ATP and UTP are equipotent, consistent with the receptor being of the P2Y2 type. Confocal microscopy was used to show that ATP-induced Ca2+ release in cumulus cells leads to a Ca2+ increase in the oocyte. Inhibition of gap-junctional communication using carbenoxolone, as assayed by dye transfer, inhibited the diffusion of the Ca2+ signal from the cumulus cells to the oocyte. Thus, provided that a Ca2+ signal is generated in the somatic cells in response to maturation-inducing hormones, it is feasible that a Ca2+ transient is generated in the oocyte. However, FSH and EGF, both of which stimulate maturation in vitro, have no effect on Ca2+ in cumulus--oocyte complexes. Furthermore, LH, which leads to meiotic maturation in vivo, did not stimulate Ca2+ release in acutely isolated granulosa cells from preovulatory mouse follicles. These studies indicate that ATP may play a role in modulating ovarian function and that diffusion of Ca2+ signals through gap junctions may provide a means of communication between the somatic and germ cells of the ovarian follicle. However, our data are not consistent with a role for Ca2+-mediated communication in hormone-mediated induction of meiosis in mice.

Electromyographic abnormalities in the urethral and anal sphincters of women with idiopathic retention of urine.

Previous concentric needle studies of the urethral sphincter in women with idiopathic urinary retention have found evidence of denervation and reinnervation as well as abnormal patterns of muscle fibre discharge--complex repetitive discharges (CRDs). In order to test the hypothesis that these abnormalities represented a more widespread disease process of pelvic floor function, we carried out an electromyographic (EMG) study of both anal and urethral sphincters in 18 women with idiopathic urinary retention. The urethral sphincter EMG was abnormal in 15 patients. These abnormalities included polyphasic and long duration potentials. Complex repetitive discharges were identified in 8 women. However, abnormalities of the anal sphincter were found in 14 of the 15 patients with abnormal urethral sphincter EMGs, polyphasic and abnormally long duration potentials being found in the anal sphincters of all 14 patients. In addition, 7 of the 8 women who had complex repetitive discharges in the urethral sphincters had similar complex repetitive discharges in their anal sphincters. Women with complex repetitive discharges had a significantly greater proportion of abnormal potentials than women with no such repetitive discharges. These results support the previous findings of electromyographic urethral sphincter abnormalities in women with idiopathic urinary retention, but also suggest that these abnormalities reflect a widespread disease process involving the pelvic floor in such patients.

A three year comparison of acute respiratory disease, shrink and weight gain in preconditioned and non-preconditioned Illinois beef calves sold at the same auction and mixed in a feedlot.

During 1969 to 1971, 78 preconditioned (PC) and 79 non-preconditioned (NPC) beef calves were purchased at the same auction and mixed in a feedlot. Preconditioned calves were weaned 30 days before the sale, used to drinking from a tank, and vaccinated against blackleg, malignant edema, infectious bovine rhinotracheitis (IBR), parainfluenza-3 (PI3) and bovine virus diarrhea (BVD) in 1970 and 1971, and Pasteurella hemolytica and multocida in 1971. All vaccinations were completed two to three weeks before the sale. PC calves were given thiabenzadole. PC calves had significantly less shrink after shipment and in 1971 significantly more rapid daily gain during the first weeks of the feeding period. In 1969 more PC calves were treated for acute respiratory disease than NPC calves during an outbreak of PI3 and BVD infection. In 1970 and 1971 fewer PC than NPC calves were treated for acute respiratory tract disease during outbreaks of PI3 infection. The differences in clinical respiratory disease were significant in 1971. Inclusion of two doses of P. hemolytica and P. multocida bacterin before the sale in 1971 and use of an intranasal PI3 vaccine was considered to improve the PC program. Fecal egg counts for gastrointestinal nematodes were much lower in PC calves treated with thiabenzadole than untreated NPC calves.

The importance of carboxyl groups on the lumenal side of the membrane for the function of the Ca(2+)-ATPase of sarcoplasmic reticulum.

The conventional model for transport of Ca(2+) by the Ca(2+)-ATPase of skeletal muscle sarcoplasmic reticulum (SR) involves a pair of binding sites for Ca(2+) that change upon phosphorylation of the ATPase from being high affinity and exposed to the cytoplasm to being low affinity and exposed to the lumen. However, a number of recent experiments suggest that in fact transport involves two separate pairs of binding sites for Ca(2+), one pair exposed to the cytoplasmic side and the other pair exposed to the lumenal side. Here we show that the carbodiimide 1-ethyl-3-[3-(dimethylamino)-propyl] carbodiimide (EDC) is membrane-impermeable, and we use EDC to distinguish between cytoplasmic and lumenal sites of reaction. Modification of the Ca(2+)-ATPase in sealed SR vesicles with EDC leads to loss of ATPase activity without modification of the pair of high affinity Ca(2+)-binding sites. Modification of the purified ATPase in unsealed membrane fragments was faster than modification in SR vesicles, suggesting the presence of more quickly reacting lumenal sites. This was confirmed in experiments measuring EDC modification of the ATPase reconstituted randomly into sealed lipid vesicles. Modification of sites on the lumenal face of the ATPase led to loss of the Ca(2+)-induced increase in phosphorylation by P(i). It is concluded that carboxyl groups on the lumenal side of the ATPase are involved in Ca(2+) binding to the lumenal side of the ATPase and that modification of these sites leads to loss of ATPase activity. The presence of MgATP or MgADP leads to faster inhibition of the ATPase by EDC in unsealed membrane fragments than in sealed vesicles, suggesting that binding of MgATP or MgADP to the ATPase leads to a conformational change on the lumenal side of the membrane.

Ambulatory monitoring of bladder pressure in low compliance neurogenic bladder dysfunction.

Upper tract dilatation is an important complication of neurogenic bladder dysfunction. Risk factors include incomplete bladder emptying with large residual volumes of urine and high tonic increases in bladder pressures during artificial filling. However, on natural bladder filling many of these patients do not have high tonic increases in detrusor pressures. We compared conventional urodynamic studies with ambulatory monitoring during natural bladder filling in 66 patients with low compliance neurogenic bladder dysfunction. There were marked differences in the tonic increase in bladder pressure during filling and in compliance during artificial bladder filling compared with ambulatory monitoring. Faster filling rates during artificial filling resulted in greater end filling pressures and lower compliance but the lowest increases in bladder pressure were found during ambulatory monitoring with natural bladder filling. During natural bladder filling significantly more patients had phasic changes in detrusor pressure; a high intensity of phasic activity during ambulatory monitoring correlated with high end filling pressures during artificial bladder filling. Upper tract dilatation was associated with large volumes of residual urine, high resting bladder pressures and low bladder compliance on filling at 100 ml. per minute. However, upper tract dilatation was most strongly associated with high intensity phasic pressure activity during natural bladder filling in combination with high residual urine volumes and high resting bladder pressures. On multivariate statistical analysis the intensity of phasic pressure activity during ambulatory monitoring was the best discriminator between patients with dilated and normal upper tracts. Our study has highlighted important differences in the results obtained by artificial filling cystometry and ambulatory monitoring during natural bladder filling. In particular, high increases in pressure did not occur during natural bladder filling, apparently being replaced by phasic activity. Within this group of patients who had the high risk factor of low bladder compliance measured during artificial bladder filling, a combination of greater residual urine volumes, greater resting pressures and greater phasic activity during natural bladder filling was found in patients with upper tract dilatation.

Bladder augmentation and replacement. Urodynamic and clinical review of 25 patients.

Bladder augmentation has a role in the management of patients with neuropathic bladder dysfunction and in urinary undiversion. Several reports attest to its clinical value, but there have been few detailed urodynamic studies of its effects. We have carried out a prospective review over a 4-year period of 25 patients undergoing bladder augmentation or substitution assessed by conventional and ambulatory urodynamic studies. All patients had a detubularised reservoir made of ileum in 6, and of the ileocaecal segment in the remainder. Six patients also had an artificial sphincter fitted and 2 underwent colposuspension. There was no mortality. After operation, bladder capacity increased from 122 +/- 91 ml to 659 +/- 431 ml and there were significant decreases in the pressure rise during filling and increases in bladder compliance. Hyper-reflexia was present in 74% before operation and 23% after operation. Regular phasic activity was observed in 77% of patients at the end of filling after operation, probably due to bowel activity despite detubularisation. Four patients described urge incontinence associated with this activity. After operation, one man had persistent major stress incontinence. He has since undergone insertion of an artificial urinary sphincter (AUS) and is now completely dry. Of the remainder, 10 patients had minor, infrequent defects in continence, 9 patients with leakage when the bladder was full and 4 with occasional leakage at night. With the exception of the patient with major stress incontinence, all but one felt the operation had been worthwhile--40% reporting complete success and 52% excellent improvement. Reconstruction of the neuropathic lower urinary tract is a major surgical procedure, but the final clinical outcome is very satisfactory.

Measurement of voiding pressures on ambulatory monitoring: comparison with conventional cystometry.

A series of 20 patients underwent conventional medium fill cystometry (CMG) and ambulatory monitoring during natural bladder filling (AM). The measurement of voiding pressures by the 2 techniques was compared. The maximum subtracted detrusor contraction pressure recorded during CMG (50 +/- 30 cm H2O) was significantly less than that recorded during AM (86 +/- 35 cm H2O). Voiding pressures during natural filling are greater than those observed during conventional urodynamic studies: this finding may have important implications in the definition of bladder outflow obstruction.

Filling and voiding pressures measured by ambulatory monitoring and conventional studies during natural and artificial bladder filling.

A total of 20 men awaiting elective prostatectomy for bladder outflow obstruction underwent conventional medium filling cystometry and ambulatory monitoring of bladder pressures during natural bladder filling. Total bladder capacity was similar during both tests (medium filling cystometry 256 +/- 138 ml. and ambulatory monitoring 248 +/- 120 ml., p not significant) as was the voided volume (medium filling cystometry 180 +/- 100 ml. and ambulatory monitoring 179 +/- 88 ml., p not significant). However, the peak urinary flow rate at the end of medium filling cystometry (4 +/- 6 ml. per second) was significantly lower than during ambulatory monitoring (9 +/- 4 ml. per second, p less than 0.05). The bladder contraction pressure during medium filling cystometry (79 +/- 44 cm. water) was significantly lower than during ambulatory monitoring (107 +/- 39 cm. water, p less than 0.005). Bladder pressures during voiding recorded after natural filling were significantly greater than after artificial filling. This finding may have significant implications for the use of conventional cystometry to study conditions such as outflow obstruction.