Calyceal Diverticula: A Comprehensive Review

Calyceal diverticula are rare outpouchings of the upper collecting system that likely have a congenital origin. Stones can be found in up to 50% of calyceal diverticula, although, over the combined reported series, 96% of patients presented with stones. Diagnosis is best made by intravenous urography or computed tomography urogram. Shock wave lithotripsy (SWL) is an option for first-line therapy in patients with stone-bearing diverticula that have radiologically patent necks in mid- to upper-pole diverticula and small stone burdens. Stone-free rates are the lowest with SWL, although patients report being asymptomatic following therapy in up to 75% of cases with extended follow-up. Ureteroscopy (URS) is best suited for management of anteriorly located mid- to upperpole diverticular stones. Drawbacks to URS include difficulty in identifying the ostium and low rate of obliteration. Percutaneous management is best used in posteriorly located mid- to lower-pole stones, and offers the ability to directly ablate the diverticulum. Percutaneous nephrolithotomy remains effective in the management of upperpole diverticula, but carries the risk of pulmonary complications unless subcostal access strategies such as triangulation or renal displacement are used. Laparoscopic surgery provides definitive management, but should be reserved for cases with large stones in anteriorly located diverticula with thin overlying parenchyma, and cases that are refractory to other treatment. This article reviews the current theories on the pathogenesis of calyceal diverticula. The current classification is examined in addition to the current diagnostic methods. Here we summarize an extensive review of the literature on the outcomes of the different treatment approaches.Key words: Calyceal diverticula, Percutaneous nephrostolithotomy, Laparoscopic surgery, Shock wave lithotripsy, UreterorenoscopyCalyceal diverticula are eventrations of the upper collecting system lying within the renal parenchyma.¹ These nonsecretory outpouchings are lined by transitional cell epithelium and communicate with the main collecting system via a narrow channel, allowing for passive filling with urine. They were first described in 1841 by Rayer in “Traitements des maladies des reins.”² Thought to be either cysts or localized hydronephrosis, he used the term kyste urinaire to describe his finding of intrarenal urine-containing cavities that communicate with calyces. Other investigators reported similar findings and—depending on location and postulated etiology—described them as pelvic cysts,³ peripelvic cysts,⁴ pyelorenal cysts,⁵ pyelosynaptic cysts,⁶ pyelogenous cysts,⁷ hydrocalicosis,⁸ cystic dilatations of the calyx,⁹ congenital cortical cysts,¹⁰ congenital cystic dysplasia,^4,11 calyceal pseudocysts,¹² juxta-calyceal cysts,¹³ pelvic diverticula, ¹⁴ congenital diverticula of the calyx,¹⁵ and finally, calyceal diverticula.^16–18 Prather is credited with coining the term and the definition of calyceal diverticulum that we use today.     

Genetic elements associated with antimicrobial resistance in enteropathogenic <Emphasis Type="Italic">Escherichia coli</Emphasis> (EPEC) from Brazil

Background  

We recently observed an association of resistance with a certain enteropathogenic Escherichia coli (EPEC) serotypes and identified a conjugative plasmid, similar to plasmid pED208, that was conserved among archival O111:H2/NM and O119:H2 strains of diverse geographical origin. In this study, we sought to determine the prevalence and distribution of this plasmid among a collection of EPEC isolates from Brazil, as well as to study the susceptibilities of these isolates to antimicrobial agents.     

Linear mixture model approach for selecting fuzzy exponent value in fuzzy c-means algorithm

The implementations of both the supervised and unsupervised fuzzy c-means classification algorithms require a priori selection of the fuzzy exponent parameter. This parameter is a weighting exponent and it determines the degree of fuzziness of the membership grades. The determination of an optimal value for this parameter in a fuzzy classification process is problematic and remains an open problem. This paper presents a new and efficient procedure for determining a local optimal value for the fuzzy exponent in the implementation of fuzzy classification technique. Numerical results using simulated image and real data sets are used to illustrate the simplicity and effectiveness of the proposed method.     

Comparative bioremediation of soils contaminated with diesel oil by natural attenuation, biostimulation and bioaugmentation

Bioremediation of diesel oil in soil can occur by natural attenuation, or treated by biostimulation or bioaugmentation. In this study we evaluated all three technologies on the degradation of total petroleum hydrocarbons (TPH) in soil. In addition, the number of diesel-degrading microorganisms present and microbial activity as indexed by the dehydrogenase assay were monitored. Soils contaminated with diesel oil in the field were collected from Long Beach, California, USA and Hong Kong, China. After 12 weeks of incubation, all three treatments showed differing effects on the degradation of light (C12-C23) and heavy (C23-C40) fractions of TPH in the soil samples. Bioaugmentation of the Long Beach soil showed the greatest degradation in the light (72.7%) and heavy (75.2%) fractions of TPH. Natural attenuation was more effective than biostimulation (addition of nutrients), most notably in the Hong Kong soil. The greatest microbial activity (dehydrogenase activity) was observed with bioaugmentation of the Long Beach soil (3.3-fold) and upon natural attenuation of the Hong Kong sample (4.0-fold). The number of diesel-degrading microorganisms and heterotrophic population was not influenced by the bioremediation treatments. Soil properties and the indigenous soil microbial population affect the degree of biodegradation; hence detailed site specific characterization studies are needed prior to deciding on the proper bioremediation method.     

Effect of potassium bromate on diastase, cellulase and hemicellulase development in Nigerian malted millet (Pennisetum maiwa)

The influence of varying concentrations (0–150 mg/litre) of potassium bromate on enzyme development in Nigerian millet (Pennisetum maiwa) during sprouting and growth was assessed. Optimum diastatic, cellulolytic and hemicellulolytic activities were observed on the fifth day of germination at 28°C when 125 mg/litre of potassium bromate was applied.     

Effects of dietary selenium supplementation on parasitemia,anemia and serum proteins of Trypanosoma brucei brucei infected rats

Trypanosomosis has been associated with immunosuppression, anemia and oxidative damage while selenium possesses both immunostimulatory and antioxidative effects. This study was designed to assess the effect of dietary selenium supplementation on parasitemia, anemia, survival pattern and serum protein profiles of trypanosome-infected rats. Twenty five rats, divided into five groups (A–E) of 5 each, were treated as follows: 4, 8 and 16 ppm (ppm) of selenium in their feed, respectively throughout the experimental period and were infected with Trypanosoma brucei brucei on day 14 post supplementation, infected not supplemented and the negative control. Supplementation at 4 and 8 ppm increased the packed cell volume (PCV) and hemoglobin (Hb) concentration on day 7 of supplementation (PS) when compared with the unsupplemented groups. Following infection on day 14 PS, the PCV, Hb of 16 ppm and infected not supplemented groups were significantly (P < 0.05) lower than other groups on days 28 and 35 PS. Supplementation did not lead to significant (P > 0.05) changes on the total protein, albumin and globulin by day 14 PS. Infection, however, caused significant (P > 0.05) decrease in the total protein and albumin from day 28. The supplementation did not significantly (P > 0.05) increase the pre-patent period but caused a significant reduction in the parasitemia levels and increased survival intervals. Dietary selenium supplementation, from the results, may show promise in the management of African trypanosomosis as the supplementation was able to: reduce anemia and parasitemia and increase survival intervals of trypanosome infected rats.     

Studies on pathogenic dematiaceous fungi

Two hundred and twenty-six samples of woody materials, vegetable matter and soil were processed by the direct plating and mouse inoculation technique for the isolation of pathogenic dematiaceous fungi. The species of fungi isolated were Fonsecaea pedrosoi — 13, Cladosporium carrionii — 7 and Phialophora verrucosa — 4 isolates. The mouse inoculation technique was found to be much better than direct plating for the recovery of these fungi. Woody plant materials proved to be a good sample source for pathogenic dematiaceous fungi contributing about 90% of the isolates. All the isolates were pathogenic for mice as evidenced by the presence of dark nodular lesions containing fungal elements in the organs of experimentally infected animals.     

Wine produced from date palm (Phoenix dactylifera L.) fruits using Saccharomyces cerevisiae X01 isolated from Nigerian locally fermented beverages

Archives of Microbiology - The study focused on the production of wine from date palm fruits (Phoenix dactylifera L.) using a strain of yeast isolated from selected Nigerian locally fermented...