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The effect of cadmium, aluminum, and sulphate ions on struvite precipitation kinetics and morphology of solids obtained was investigated in this study. Thus, these ions were introduced as additives in solution where struvite precipitation was achieved. The main results obtained showed that the Cd2+ ions cause the probable co-formation, with struvite, of an amorphous phase observed from Cd2+ concentration of 10 mg/L; the addition of aluminum ions in the solution does not affect the nature of the crystalline phase, identified as struvite. However, these ions cause the formation of agglomerates of larger and larger as the concentration rises. Moreover, their increasing improved significantly the yield of phosphates removal; although the sulfate ions have no effect on the nature of the precipitated phase identified as struvite, independently of molar ratio studied, they affect the thermal decomposition of struvite. This latter is done in a single step by increasing the concentration of these ions for the SO42−/PO43− molar ratio of 8.

In this work, a new method is proposed to the widely neglected problem of Arabic font recognition, it uses global texture analysis. This method is based on fractal geometry, and the feature extraction does not depend on the document contents. In our method, we take the document as an image containing some specific textures and regard font recognition as texture identification. We have combined both techniques BCD (box counting dimension) and DCD (dilation counting dimension) to obtain the main features. The first expresses texture distribution in 2-D image. The second makes possible to take on the human vision system aspect, since it makes it possible to differentiate one font from another. Both features are expressed in a parametric form; then four features were kept. Experiments are carried out by using 1000 samples of 10 typefaces (each typeface is combined with four sizes). The average recognition rates are of about 96.2% using KNN (K nearest neighbor) and 98% using RBF (radial basic function). Experimental results are also included in the robustness of the method against written size, skew, image degradation (e.g., Gaussian noise) and resolution, and compared with the existing methods. The main advantages of our method are that (1) the dimension of feature vector is very low; (2) the variation sizes of the studied blocks (which are not standardized) are robust; (3) less samples are needed to train the classifier; (4) finally and the most important, is the first attempt to apply and adapt fractal dimensions to font recognition.

To evaluate whether the overall safety and efficacy profile of percutaneous surgery for urinary stone disease in older (70 years) patients might influence the decision for the procedure in the elderly.A large database was created from our patients (n = 1058) who underwent percutaneous surgery for stone disease between 1991 and 2003 in the Scottish Lithotriptor Centre, including clinical and operation details for each case. Only percutaneous nephrolithotomy cases with full details were studied (n = 779) and were grouped into two age groups: (1) between 17 and 69 years and (2) over 70 years. Statistical analysis evaluated differences in terms of operation-related adverse events, stone-free success rates, and clinical success rates (including stone-free cases and cases with residual fragments4 mm). Further analysis was performed for the same endpoints after stratification of the patients by (1) previous stone procedures and (2) special clinical features.In the overall database, no statistically important differences were found between the two groups in terms of stone burden before surgery, adverse events rates, complete stone-free rates, and clinical success rates. However, a statistical trend toward higher clinical success rates in favor of the younger group was seen (P = 0.051). Stratification of our database according to previous stone disease procedures or special clinical or anatomic characteristics has only shown a statistically important difference for clinical success rates in favor of the older group without special features (P = 0.01).In experienced hands, age-related morbidity or age itself should not be a discouraging consideration when deciding on performing percutaneous nephrolithotomy, as the procedure is as equally feasible and safe in the elderly as in the younger patient population.

OBJECTIVE To review the safety and efficacy of supracostal puncture during percutaneous nephrolithotomy (PCNL) for renal calculi. PATIENTS AND METHODS Over a 12-year period, 66 patients had either an upper-pole puncture alone or combined with middle- or lower-pole puncture during PCNL for renal calculi. All punctures were made by an experienced uroradiologist and were either supra- or subcostal. We retrospectively reviewed all case notes and radiographs to determine stone-clearance rates and complications associated with the site and number of punctures. RESULTS There was an overall stone-free rate of 78% with upper-pole puncture alone or combined with middle- or lower-pole puncture. There was a 3% thoracic complication rate with upper pole punctures, and an overall complication rate of 30% for both thoracic and non-thoracic complications. CONCLUSION Upper-pole puncture in PCNL is associated with minimum morbidity if done by an experienced urologist or radiologist. The stone-free rate appears to be more dependent on stone size and complexity than the site of puncture.

In this section this month, we have two papers. The first is from authors from Scotland. They present a review of patients with an extended follow-up who have undergone extracorporeal shock wave lithotripsy (ESWL) or percutaneous nephrolithotomy (PCNL) for calyceal diverticular stones over a 15-year period to assess long-term outcome, irrespective of treatment. They concluded that PCNL is an effective and durable means of treating calyceal diverticular stones, regardless of stone size or location of the diverticulum. Despite low stone-free rates with ESWL, most patients are rendered symptom-free with minimal complications. The second paper is from the USA; the authors discuss the new generation of flexible ureteroscopes, which provide exaggerated active deflection to facilitate intrarenal manipulation. They compared the relative ease of manipulation around a calyceal model. The authors concluded that the Wolf Viper proved superior for manipulation in the hands of experienced endoscopists. OBJECTIVE To review patients with an extended follow-up after extracorporeal shock wave lithotripsy (ESWL) or percutaneous nephrolithotomy (PCNL) for calyceal diverticular stones (CDS), over a 15-year period, assessing the long-term outcome. PATIENTS AND METHODS In all, 56 patients were treated for symptomatic CDS disease by ESWL (38) or PCNL (18). The stone-bearing diverticula were in the upper calyces in 26, middle calyces in 24 and lower calyces in six patients, and in the right kidney in 22 and in the left in 34. The most frequent symptom was ipsilateral flank pain (84%) and 32% of patients presented with associated chronic urinary tract infections. In a retrospective analysis, we assessed stone size, diverticulum location, stone-free rate, symptom-free rate, complications and extended follow-up. RESULTS In the short-term in the ESWL group, 21% of patients were stone-free and 61% were asymptomatic; 8% developed symptoms and 8% developed recurrence or stone-growth in the long term. There were six minor complications. In the PCNL group, 15 patients (83%) were stone-free in the short term; two had a recurrence (11%) and two had stone growth (11) in the long term. There were three complications after PCNL. CONCLUSIONS This series shows that PCNL is an effective and durable means of treating CDS, regardless of stone size or location of the diverticulum. Despite low stone-free rates with ESWL, most patients were rendered symptom-free with minimal complications. The long-term recurrence rates, 8% for ESWL and 11% for PCNL, were comparable.

Summary There is controversy over whether shock wave lithotripsy (SWL) or ureteroscopy (URS) is the best management of ureteric calculi, especially for stones located in the upper ureter. This study compares URS and SWL management of upper ureteric stones directly for the first time using a different analysis tool, the matched pair analysis study design. This method enables meaningful comparisons to be made on a small number of matched patients, using precise like-for-like matching. Adult patients undergoing primary treatment of solitary radiopaque proximal ureteric stones were identified. Patients with stents, nephrostomies or stones at the pelvi-ureteric junction were excluded. Patients had a minimum of 3 months follow-up. Patients treated by primary URS were matched using four parameters (sex, laterality, stone size and location) to patients treated on a Dornier Compact Delta Lithotriptor. A total of 1479 patients had URS or SWL from which 27 upper ureteric stone matched pairs were identified. Three-month stone free rates were 82% for URS and 89% for SWL (McNemar's test, p = 0.625). Re-treatment was required in 11% and 26% following URS and SWL respectively (p = 0.219). Forty-one per cent of URS patients required an ancillary treatment, such as stent removal, compared with only 22% of SWL patients (p = 0.227). Introduction of a holmium:YAG laser for use with URS improved the stone free rate for URS to 100%. Using a robust like-for-like comparison of similar patients with very similar upper ureteric stones the outcomes following SWL and URS were comparable. Choice of treatment should therefore be based on parameters such as availability of equipment, waiting times and patient preference.

We sought to identify whether changes in technology and local practice have improved outcomes in the minimally invasive management of pediatric stone disease.We reviewed retrospectively case notes and imaging from 1988 to 2003, noting treatment modality, stone-free rates, ancillary therapy and complications.A total of 122 children (140 renal units) with a mean age of 7.7 years underwent 209 extracorporeal shock wave lithotripsy (SWL) sessions. Stone size ranged from 6 to 110 mm. Stone-free rates were 84% for cases involving stones smaller than 20 mm, and 54% for those involving stones 20 mm or greater. For complex calculi 40% of patients were stone-free and 45% required ancillary procedures, with an overall complication rate of 26%. A total of 37 children (43 renal units) with a mean age of 6.4 years underwent 46 percutaneous nephrolithotomies (PCNLs). Stone size ranged from 8 to 155 mm. The overall stone-free rate was 79%. Of these patients 34% required ancillary procedures, with a major complication rate of 6%. A total of 35 children (35 renal units) with a mean age of 5.9 years underwent 53 ureteroscopies. Holmium laser was the most effective treatment modality in this group, with a 100% stone-free rate and no complications.For most renal stones smaller than 20 mm SWL was the most effective primary treatment modality. There was no statistical difference between the 2 lithotriptors for stone-free or ancillary procedure rate. The stone-free rate was dependent on stone size rather than type of lithotriptor. For renal stones 20 mm or greater and staghorn calculi we switched from SWL to PCNL as primary treatment, as stone-free rates were higher and the ancillary procedure and re-treatment rates were lower with PCNL. Electrohydraulic lithotripsy and pulse dye laser were initially used to treat ureteral stones. However, with the introduction of holmium laser technology we achieved higher stone-free rates and lower complication rates. Holmium laser lithotripsy is now used as a primary treatment modality for ureteral stones.

Objective: The factors associated with a successful outcome for the treatment of urinary lithiasis are well described. We reviewed current methods of imaging utilised in stone treatment planning, with specific reference to their ability to identify predictors of outcome. Methods: A literature search for articles concerning the investigation and management of patients with urolithiasis was conducted through PubMed ( www.ncbi.nlm.nih.gov/PubMed/ ). In addition a hand search of the abstract books from the most recent major urological conferences was performed to identify data of interest that have so far been presented in abstract form only. Results: Non-contrast computed tomography is superior in terms of diagnostic efficacy, with sensitivity and specificity approaching 100%. The intravenous urogram and contrast CT with 3-dimensional reconstruction provide the best anatomical detail. Conclusion: Although non-contrast helical computed tomography is the most sensitive investigation for suspected ureteric colic, the anatomical and functional information afforded by intravenous urography remains important for treatment planning in some patients.

Objective To compare endopyelotomy and primary reconstructive procedures in patients with pelvi-ureteric junction (PUJ) obstruction and with risk factors for endopyelotomy failure. Patients and methods Nineteen patients (eight female and 11 male, mean age 34.5 years, range 15–82) underwent endoluminal ultrasonography (US) before treatment for PUJ obstruction; the US findings were used to direct the treatment. Patients with unavoidable crossing vessels, massive hydronephrosis and crossing vessels associated with previous failed endopyelotomy were selected for reconstructive surgery. The clinical results of these patients (group 1) were compared with 12 consecutive patients who had undergone endopyelotomy before the use of endoluminal ultrasonography (group 2). Results Imaging detected 17 crossing vessels in 13 of the 19 patients. Six patients underwent primary reconstructive surgery and 13 underwent endopyelotomy. The endoluminal US findings changed treatment in some way in nine patients. Endopyelotomy was successful in 12 of the 13 patients and reconstructive surgery successful in five of six patients. The success after endopyelotomy improved from eight in 12 patients in group 2 to 12 of 13 in group 1 (P = 0.16, NS). Conclusions Endoluminal US can be used to select patients in whom endopyelotomy is likely to fail. Using primary reconstructive procedures in these patients might improve the overall outcome, but these preliminary findings need to be confirmed in a larger study.

Crossing vessels at the ureteropelvic junction are associated with bleeding complications and a higher risk of failure after endopyelotomy. We compared computerized tomography (CT) angiography and endoluminal ultrasound for detecting crossing vessels before planned endopyelotomy.Preoperatively patients underwent CT angiography. Intraoperative evaluation included retrograde ureteropyelography, endoluminal ultrasound and ureteroscopy. Intraoperative findings were used to direct treatment.Endoluminal ultrasound detected 19 crossing vessels in 14 of 20 patients (70%), while CT detected 9 crossing vessels in 7 (35%). Endoluminal ultrasound identified a septum between the ureter and renal pelvis in 7 patients (35%) but CT demonstrated none. On the basis of imaging findings we selected 5 patients for pyeloplasty, and endoluminal ultrasound accurately predicted the absence or presence of crossing vessels in all 5. CT angiography was accurate in 3 patients. However, in 2 patients a total of 4 vessels were missed by CT. A total of 15 patients underwent endopyelotomy with no bleeding complications. The presence or absence of a septum on endoluminal ultrasound was confirmed in all patients. Imaging findings altered the treatment chosen in 4 patients and changed the direction of the incision at the ureteropelvic junction in another 4. Clinical and radiographic success was achieved in all 13 patients (100%) with adequate followup.Endoluminal ultrasound was more sensitive than CT angiography for identifying crossing vessels and septa. Treatment based on endoluminal ultrasound findings may decrease complications and improve the results of minimally invasive treatment for ureteropelvic junction obstruction.

To assess the effect of anatomic factors, especially the angle of the lower-pole infundibulum, on stone clearance following shock wave lithotripsy (SWL) in order to determine selection criteria for percutaneous nephrolithotomy.We retrospectively analyzed 116 patients with single lower-pole stones measuring 11-20 mm treated with SWL. Intravenous urograms were reviewed to measure the infundibulopelvic angle, the angle of the infundibulum to the vertical, and the anatomy of lower-pole calyces.The overall stone-free rate was 52%. Factors most closely associated with a stone-free status were obtuse infundibulopelvic angle, lack of calyceal distortion, and a large infundibular diameter. The infundibulopelvic angle was the only factor to attain significance in predicting stone-free status (p = 0.012). The size of the stone did not predict eventual stone-free status (p = 0.911), but larger stones were more likely to require intervention after SWL.For solitary lower-pole stones 11-20 mm in size, the angle of the lower-pole infundibulum as it relates to the pelvis plays a role in eventual stone clearance and should be taken into account before choosing a mode of treatment.

A double polyphosphate of ammonium and erbium NH 4 Er(PO 3 ) 4 (type IV) has been prepared for the first time. It crystallizes in a monoclinic system and its parameters are a = 11.02(2) A , b = 7.70(1) A , c = 10.39(2) A , β = 107.7(1), V = 839.9 A 3 , d x = 3.14, Z = 4. The corresponding space group is P2 1 n . This compound has been identified as a chain structure by infrared spectra. A thermal analysis study of two condensed polyphosphates NH 4 Er(PO 3 ) 4 -IV and HEr(PO 3 ) 4 is presented; TG and DTA curves are given.

Lithotripsy using new-generation machines requires minimal anesthesia and so can easily be given in an outpatient setting. We report our experience with the Dornier Compact Delta lithotripter in the primary management of lower ureteral stones.We identified 128 patients treated with SWL for lower-ureteral stones between April 1999 and August 2001. Complete follow-up was available for 112 patients. Their ages ranged from 19 to 78 years, with women accounting for 23%. Only three patients had a ureteral stent in situ. All patients were routinely followed up at 2 weeks with a plain film. The timing of further follow-up depended on the initial response to treatment.Fragmentation occurred in 83 of 112 stones (74%): 93% of the successful cases and 43% of the unsuccessful ones. A total of 59 patients (53%) were stone free after one treatment. This figure increased to 73 (65%) after a second treatment. The mean size of the successfully treated stones was less than that of the failed stones (7.6 v 8.7 mm), although the difference did not reach statistical significance. Stone-free rates decreased as stone size increased, being 71% for the 28 stonesor =5 mm in diameter, 65% for the 52 stones 6 to 9 mm, 64% for the 25 stones 10 to 14 mm, and 42% for the 7 stonesor =15 mm.When SWL can be delivered promptly in an outpatient setting, it remains a useful first-line treatment for lower ureteral stones. Although it is not as effective as ureteroscopy, its use can avert the need for more invasive treatment in half to two thirds of patients. It should be limited to stones15 mm.

Urosepsis after percutaneous nephrolithotomy (PCNL) is a severe complication, and its avoidance can sometimes be difficult despite antibiotic prophylaxis. Authors from the UK with a considerable experience in this procedure describe a prospective controlled study using ciprofloxacin for 1 week before PCNL, and found that it significantly reduces the risk of urosepsis. OBJECTIVE To evaluate whether 1 week of ciprofloxacin before percutaneous nephrolithotomy (PCNL) in patients with stones of ≥ 20 mm or pelvicalyceal dilatation, reduces urosepsis, as we previously reported that such patients have four times the risk of urosepsis after PCNL. PATIENTS AND METHODS Patients undergoing PCNL, and who fulfilled strict selection criteria, were recruited prospectively into a study which was conducted in two phases. The study methods were similar to those previously described; patients with dilated pelvicalyceal systems and/or stones of ≥ 20 mm from phase 1 (previously published) acted as controls. In the subsequent phase, the same selection criteria applied and only those with stones of ≥ 20 mm and/or dilated pelvicalyceal systems were given ciprofloxacin 250 mg twice daily for 1 week before PCNL and comprised the treatment arm. Midstream urine samples, renal pelvic urine and fragmented stones were collected to assess culture and sensitivity. Systemic inflammatory response syndrome (SIRS) was used to define urosepsis after PCNL. The urologists monitoring the patients after PCNL and conducting the analysis were all unaware of the characteristics of the stones or intravenous urography findings before PCNL. In all, 115 patients (54 in phase 1 and 61 in phase 2) were recruited, of whom 46 in phase 1 and 52 in phase 2 had stones of ≥ 20 mm and/or a dilated pelvicalyceal system, and became the control and treatment arms, respectively. RESULTS The patient demographics were similar in both arms. There was three times less risk of upper tract infection (relative risk 3.4, 95% confidence interval 1.0–11.8, P = 0.04) and SIRS (2.9, 1.3–6.3, P = 0.004) in the patients receiving ciprofloxacin (treatment arm). CONCLUSIONS The administration of oral ciprofloxacin for 1 week before PCNL in patients with stones of ≥ 20 mm or dilated pelvicalyceal systems significantly reduced the risk of urosepsis.

THE PATIENT is a 34-year-old woman who is 27 weeks pregnant with her second baby. At 12 weeks into her pregnancy, she was found to have an obstructing right renal stone and had a stent placed. At 17 weeks, she was admitted with acute colic and was found to have an obstructed, encrusted stent, which was removed cystoscopically. A nephrostomy tube was placed. She has undergone nephrostomy tube changes but requires them nearly every 2 weeks because of acute encrustation, even using 14F tubes. Now she has persistent bacteriuria, and her gynecologist is concerned she may go into premature labor because of the frequent manipulations required to keep her nephrostomy tube draining. The site has been relocated from a middle to a lower calix to improve pain control and drainage. It is likely she will require some definitive procedure prior to the safer, 32-week time. At 27 weeks, she is high risk regardless of the approach taken. Ultrasound scanning shows a 2.03 2.0-cm renal pelvis stone and numerous stone fragments in the upper pole and on the nephrostomy tube, none larger than 8 mm. There is minimal hydronephrosis and a normal ureter. No radiographs are available to you at this time.

Introduction: Horseshoe kidney is the commonest congenital renal fusion anomaly, and is often complicated by urolithiasis. We focus on our 16 years of experience with stone management in horseshoe kidneys. Materials and Methods: We reviewed the progress of 44 patients treated between 1987 and 2002. Shock wave lithotripsy (SWL) was used in 25 patients; the average stone surface area was 91 (range 10–1,600) mm2 and average follow-up was 36.5 (range 1–91) months. 19 patients underwent percutaneous nephrolithotomy (PCNL); the average stone surface area was 197 (range 6–2,400) mm2. Follow-up data are available for 8 patients and the average follow-up was 42.3 (range 3–144) months. Results: In the SWL group the 3-month stone-free rate (SFR) was only 31%. In the PCNL group the SFR was 75% on the postoperative day-1 KUB. Complications occurred in 9 patients. Conclusions: Stone management in horseshoe kidneys is challenging: PCNL produces a higher SFR with minimal major complications and failed access. PCNL thus appears to be the preferred management option in patients with urolithiasis in horseshoe kidneys.

Urosepsis due to manipulation during percutaneous nephrolithotomy (PCNL) can be catastrophic despite prophylactic antibiotic coverage, and negative midstream urine culture and sensitivity testing (CS). It has been postulated that bacteria in the stone may be responsible for systemic infection. In this prospective study we determined the correlation between different sites of urine sampling, including stones, and also ascertained which is more predictive of urosepsis.All patients undergoing PCNL who fulfilled our selection criteria were recruited. The samples collected were 1) midstream urine and bladder urine at cystoscopy, 2) renal pelvic urine collected at percutaneous puncture of the pelvicaliceal system and 3) extracted and later fragmented stones. They were sent immediately for CS. Patients were monitored for systemic inflammatory response syndrome (SIRS).A total of 54 procedures were suitable for analysis. Midstream urine CS was positive in 11.1% of cases, stone CS was positive in 35.2% and pelvic CS was positive in 20.4% (p = 0.009). Pelvic urine CS predicted infected stones better than bladder urine CS. Of the patients 37% had SIRS and 3 experienced septic shock. Patients with infected stones or pelvic urine were found to be at a relative risk for urosepsis that was at least 4 times greater (p = 0.0009). Bladder urine did not predict SIRS. Stone CS had the highest positive predictive value of 0.7. Preoperative hydronephrosis correlated with infected pelvic urine. No patients with urosepsis had positive blood CS.The results of this study suggest that positive stone CS and pelvic urine CS are better predictors of potential urosepsis than bladder urine. Therefore, routine collection of these specimens is recommended.

To report our experience with ureteroscopy in the treatment of pediatric urinary tract calculi and present a review of the literature.Between 1988 and 2003, 52 ureteroscopic procedures were performed in 25 male and 10 female children aged 11 months to 15 years (mean 5.9 years). Using a semirigid 6.8F 43-cm ureteroscope and routine antibiotic prophylaxis, stones were fragmented with a pulsed-dye laser (N = 14; stone size 6-15 mm with a mean of 9.6 mm), electrohydraulic lithotripsy (EHL) (N = 26; stone size 3-20 mm with a mean of 8.4 mm), or a holmium laser (N = 7; stone size 5-15 mm with a mean of 10 mm); removed by basket extraction (N = 5; stone size 5-8 mm with a mean of 7 mm); or both. Stenting or ureteral dilatation was not performed routinely.With the pulsed-dye laser, there was an overall stone-free rate of 72%. Complications consisted of one ureteral perforation and one stenosis of the intramural portion of a megaureter (14% complication rate). With EHL, the overall stone-free rate was 92%. Complications consisted of one case each of ureteral perforation and incipient urinary retention and five of mild fever (27%). With the holmium laser, the overall stone-free rate was 100%, and there were no complications. Basketing likewise produced a 100% stone-free rate, and there was one complication, a mucosal tear in a patient who also underwent pulsed-dye laser lithotripsy.Ureteroscopy is a safe and effective means of treating the majority of pediatric ureteral calculi, although retreatment rates are higher with multiple stones and in younger children. Dilatation of the vesicoureteral junction is usually not necessary with ureteroscopes8F, nor is ureteral drainage required after uncomplicated ureteroscopy. The holmium laser is the most effective and safest method of fragmentation regardless of stone composition. Ureteroscopy for this indication should be performed only by an experienced endoscopist.

This paper searches for the most effective technology for agricultural growth in Africa on the basis ofFAO data available during the last forty years. The paper discusses the challenges for agriculturalgrowth and evaluates the development assistance that was made by donors to the agricultural sector inAfrica in comparison to the sector’s performance and its growth during the last two decades. Ananalysis of the total versus per capita food production is conducted in relation to food exports andimports to identify the magnitude of the food problem in Africa and raise awareness of its future trend inthe search for practical solutions.The paper analyses five major variables of food production to explain the poor performance of theagricultural sector and concludes on the most effective factor to accelerate food supply as a mean topoverty reduction in Africa. In addition to the graphical analysis, a simple ordinary least squares (OLS)model is used to estimate an African food production and explain some of the divergences. Further, analternate specification uses only three variables in a logarithmic model to confirm results obtained fromthe graphical analysis and the OLS model. The variables included in the analysis are land expansion,irrigation, mechanization, high yielding varieties, and fertilizers.The findings of the study suggest that the most effective production factors for increasing food supplyand reducing poverty are the use of high yielding varieties and improved seeds along with the applicationof appropriate fertilizers. Since high yielding varieties are produced by the agricultural researchservices, the paper looks more deeply into biological gradients and the yield potential impact throughthe African experience. The findings show that HYV seeds and fertilizers would increase cereal productionby 75 percent with appropriate extension. The study examines other evidence from agriculturalresearch in Africa and concludes that the field ex-post rate of return for the application of agriculturaltechnologies in most of the cereals reaches 97 and 87 percent.Having shown that biotechnology is the only effective technique for future food supply growth, attentionis given to the African capacity of agricultural research and technology. The paper examines the ingredientsof research and its efficiency and sustainability. Further, the paper developed and proposed ananalytical technique using a capacity compound factor (research return and researchers intensity) tocategorize African countries into four groups based on their AgGDP, research expenditure, number ofresearchers and population in each country. This identifies the need to strengthen the existing researchinstitutions and establish a systematic improved seed production and distribution system in the Africancountries strengthened by rural infrastructure and marketing development.For poverty to be reduced in Africa, the paper provides several scientific evidences that biotechnologyis the only way for boost food supply surplus. Poverty in Africa can be significantly and sustainablyreduced in a short period of time through intensive support to the usage of improved seeds, tissueculturing and micro-propagation along with self-reliance in the production of fertilizers. In this respect,the paper proposed a four-component strategy for rural development and poverty reduction in Africa.The four components are i) capacity building for technology transfer; ii) rural infrastructure for improvedlinkage to markets; iii) promotion of private sector for pre and post-harvest commercial activities;and iv) rural micro-finance for accessibility to farm inputs.

Encrustion of ureteral stents is a well-known phenomenon which can be treated easily if recognized promptly. Severe encrustation, however, which leads to renal impairment, presents a challenge in management.Four patients with encrusted stents were referred to our institution for management. All had impaired function of the affected kidney. Each was managed by either retrograde ureteroscopy or a combination of percutaneous and ureteroscopic procedures.All four of the patients were rendered stone free following an average of 2.5 (range 1-3) procedures. Renal function improved in all patients postoperatively.Encrustation is a potentially serious complication of the use of ureteral stents, as it can lead to renal impairment. Timely endourologic intervention can result in recovery of renal function.

Objective To assess the effect of extracorporeal piezoelectric lithotripsy (EPL) on the contractility of the human pelvicalyceal system. Patients and methods Contractions of the pelvicalyceal system were measured in 12 patients (mean age 55 years) before and after EPL. Pelvicalyceal pressure was measured via a Cope nephrostomy tube which had remained in situ following stone debulking procedures days or weeks earlier. All patients were treated using a Wolf Piezolith 2300 lithotripter. Results The pelvicalyceal systems of two patients were acontractile before and after treatment. Immediately after treatment, contractions were completely abolished in eight of the remaining 10 systems, and reduced in frequency in the other two. All 10 systems regained contractions 24 h after treatment. Conclusion Piezoelectric lithotripsy temporarily abolishes upper urinary tract motility.

Renal aspergillomas have been reported only rarely. We report a case of Aspergillus flavus colonization of the renal pelvis and upper ureter of a patient with concomitant urinary schistosomiasis. The diagnosis was based on the demonstration of characteristic hyphal elements on direct microscopy and isolation of the fungus in culture. The patient was successfully treated with liposomal amphotericin B. This case emphasizes the importance of direct microscopic examination of urine specimens for prompt diagnosis of fungal infections of the urogenital system. Renal aspergilloma should be considered in the differential diagnosis of filling defects of the urinary tract, especially in patients who are immunocompromised.

Small persistent fragments (less than or equal to 4 mm) following extracorporeal shock wave lithotripsy have been termed clinically insignificant residual fragments (CIRF), but their presence may be associated with an increased rate of development of recurrent symptomatic renal calculi. We have adopted a policy of further extracorporeal piezoelectric shock wave lithotripsy (EPL) for patients with CIRF in an attempt to promote complete clearance. A series of 22 patients with a mean initial stone burden of 16 mm (range 7-48) developed CIRF after a median of 2 EPL treatment sessions (range 1-9). CIRF were in the lower calices (n = 20), middle calices (n = 1) and upper calices (n = 1). These calices were normal (n = 6), slightly dilated (n = 9), moderately dilated (n = 2) or grossly dilated (n = 5). After 6 to 14 months, patients underwent a further session of EPL. One month later, 3 patients with normal calices showed a considerable reduction in CIRF, but all other patients showed no change. When CIRF form in normal calices a further session of EPL may promote clearance. However, when calices containing CIRF are significantly dilated, further EPL is of no value.