Characterization of intrapelvic pressure during ureteropyeloscopy with ureteral access sheaths

Rehman, Jamil; Monga, Manoj; Landman, Jaime; Lee, David I.; Felfela, T.; Conradie, M.; Srinivas, R.; Sundaram, Chandru P.; Clayman, Ralph V.

doi:10.1016/s0090-4295(02)02440-8

Cited by 254 publications

(141 citation statements)

References 16 publications

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Section: Resultsmentioning

confidence: 99%

“…[8][9][10] The absolute configuration at C-2 was also established by Horeau's procedure 11,12) (see the Experimental Section). The structure of 1 could be assigned to be methyl 2b(2S)-hy- 13) and further confirmed through acid hydrolysis of 2 which provided various products, among which the glycone could be separated and identified as D-galactose by comparing the retention time of its trimethylsilyl (TMS) ether with that of the standard in gas chromatography (GC) and the sign of its optical rotation.…”

Section: Resultsmentioning

confidence: 99%

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Tyrosinase-Inhibitory Long-Chain Esters from Amberboa ramosa

Khan

Azhar-ul-Haq

Afza

et al. 2005

CHEMICAL & PHARMACEUTICAL BULLETIN

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The genus Amberboa belongs to the family Compositae and comprises six species. One of these is Amberboa ramosa JAFRI, which is an annual herbaceous plant found in India and Pakistan. The plant has tonic, aperient, febrifuge, deobstruent, cytotoxic, and antibacterial activities.1) Previously triterpenoids, flavanoids, steroids, and steroidal glycosides have been reported from this species.1,2) Here we report the isolation and structure elucidation of long-chain esters 1 and 2, along with two known compounds tricontane (3) 3) and apigenin (4). 4)Tyrosinase (EC 1.14.18.1) is a multifunctional copper-containing enzyme widely distributed in plants and animals. It catalyzes the oxidation of monophenols, o-diphenols, and o-quinones. Tyrosinase is known to be a key enzyme for melanin biosynthesis in plants and animals. Tyrosinase inhibitors therefore can be clinically useful for the treatment of some dermatologic disorders associated with melanin hyperpigmentation. They also find use in cosmetics for whitening and depigmentation after sunburn. It has recently been shown that other factors such as metal ions and the TRP-1 and TRP-2 enzymes also contribute to the production of melanin. However, tyrosinase plays a critical regulatory role in melanin biosynthesis. Therefore many tyrosinase inhibitors that suppress melanogenesis have been actively studied with the aim of developing preparations for the treatment of hyperpigmentation. 5) Compounds 1 and 2 showed strong to moderate inhibitory activity against tyrosinase. Results and DiscussionThe chloroform-soluble fraction of the whole plant of A. ramosa was subjected to column chromatography over flash silica eluted with different mobile phases. Compounds 1-4 were finally obtained and their structures established by IR, mass, and NMR spectroscopy including 2D NMR techniques. Compound 1 was isolated as a colorless powder. The molecular formula C 34 H 66 O 3 was determined based on the HR-EI-MS, FD, and 13 C-NMR spectra. HR-EI-MS showed a molecular ion peak at m/z 522.5017 (Calcd for C 34 ϩ indicated a double bond at C-7. The losses of 31 and 29 mass units from the [M] ϩ peak were due to the elimination of methoxy and ethyl groups, respectively. The position of the double bond was also confirmed by oxidative cleavage with osmium tetraoxide which gave a mixture of products, among which hexacosanal could be isolated and identified. The 1 H-NMR spectrum displayed a triplet at d 0.85 (Jϭ7.0 Hz) and a broad singlet at d 1.23 typical of a straight-chain hydrocarbon. It also showed signals at d 5.40 (1H, dt, Jϭ16.3, 6.1 Hz), 5.37 (1H, dt, Jϭ16.3, 6.1 Hz), 3.94 (m), and 3.85 (br s) for olefinic protons, aH (H-2), and methoxy protons, respectively. The 13 C-NMR spectrum (BB and DEPT) showed signals at d 175.6, 130.7, and 129.6 which could be assigned to the carbonyl and olefinic carbons, respectively. One oxygenated methine and a methoxy carbon resonated at d 72.2 and 51.4, respectively. The signals observed between 29.0-29.6 indicated the presence of a long chain. The stereochemis...

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Tyrosinase-Inhibitory Long-Chain Esters from Amberboa ramosa

Khan

Azhar-ul-Haq

Afza

et al. 2005

CHEMICAL & PHARMACEUTICAL BULLETIN

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“…Thus fURS also facilitates removal of small stone fragments by this way. [20] Various papers have shown that it decreases the operation time, protects the flexible ureteroscope, and increases the SFR. [21,22] Despite these advantages, its benefit, risk and cost should be kept in mind.…”

Section: Ureteroscopementioning

confidence: 99%

Retrograde intrarenal surgery for renal stones - Part 1

Cleynenbreugel

Kılıç

Akand

2017

Turkish Journal of Urology

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The main aim in the treatment of renal stones is to clearance of the stones completely with the least morbidity. Parallel to the improvements in technology during recent years, new flexible ureterorenoscopes and effective lithotripters such as holmium laser have been developed, thus retrograde intrarenal surgery (RIRS) has become an efficient and safe option in the management of urinary system stone disease with a gradually increasing popularity. Therewithal, innovations in auxiliary equipment such as guide-wires, ureteral access sheath and stone baskets have made this procedure more effective. With this modality, nowadays, the vast majority of renal stones can be treated successfully without need of open surgery or percutaneous nephrolithotomy. RIRS can be used as a primary treatment in patients with renal stones smaller than 2 cm, in cases with prior unsuccessful shock wave lithotripsy (SWL), infundibular stenosis, renoureteral malformation, musculoskeletal deformity, bleeding diathesis as well as obese patients. The efficiency of this procedure has been also proved in pediatric patients. In the first part of this detailed review for RIRS, history, indications and contraindications, preoperative preparation, antibiotic prophylaxis, anesthesia, surgical technique related to flexible ureteroscopes and auxiliary equipment being used, postoperative care and complications of this operation are discussed with up-to-date literature.

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“…The low fragility of brushite stones observed in vitro is consistent with the clinical finding that they are relatively SWL-resistant; consequently, these stones typically require endoscopic treatment. Moreover, brushite stone formers tend to be highly metabolically active, with high recurrence rates even when patients have been rendered stone free after surgery (1). Therefore, insight into the physicochemical causes of brushite stone formation may facilitate management of these patients, who in my practice constitute a most challenging group of patients to manage medically.…”

Section: Editorial Commentmentioning

confidence: 99%

“…However, the treatment of larger stones is associated with longer operative times and a greater potential for fluid absorption and/or bacteremia. A recent cadaveric study assessed renal pelvic and ureteral flow characteristics during flexible ureteroscopy either with or without a ureteral access sheath and determined that use of a ureteral access sheath was associated with low intrarenal pelvic pressures regardless of irrigation pressure used, and significantly lower pressures with ureteroscopy at all locations in the ureter compared with ureteroscopy using a bare ureteroscope (1).…”

Section: Editorial Commentmentioning

confidence: 99%

Stone disease

Pearle¹

2004

Int. braz j urol.

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Purpose: We determined whether the biochemical and physicochemical backgrounds of patients with brushite stones differ from those with hydroxyapatite and calcium oxalate stones.Materials and Methods: From a computer data base of patients completing ambulatory evaluation 19 with brushite stones, 24 with hydroxyapatite stones and 762 with calcium oxalate stones were identified with the specified composition in greater than 70% of stones.Results: Absorptive hypercalciuria type I was present in 63% of patients with brushite, 17% with hydroxyapatite and 30% with calcium oxalate stones. Distal renal tubular acidosis was noted in 32% of patients with brushite, 42% with hydroxyapatite and 3% with calcium oxalate stones. Mean urinary calcium in the brushite group was significantly higher than in the hydroxyapatite and calcium oxalate groups (265 +/-125 vs 186 +/-103 and 187 +/-95 mg daily, respectively). Urinary pH in the brushite group was slightly but significantly higher than in the calcium oxalate group (6.15 +/-0.30 vs 5.91 +/-0.42). The brushite relative saturation ratio in the brushite group was marginally higher than in the hydroxyapatite group and significantly higher than in the calcium oxalate group (3.25 +/-2.03 vs 2.34 +/-1.51 and 1.83 +/-1.66, respectively).Conclusion: Patients with predominantly brushite stones could be distinguished from those with predominantly hydroxyapatite and calcium oxalate stones by higher urinary saturation with respect to brushite due mainly to hypercalciuria from absorptive hypercalciuria. Editorial CommentBrushite stone formers constitute a particularly aggressive and difficult-to-treat subset of calcium stone formers. The low fragility of brushite stones observed in vitro is consistent with the clinical finding that they are relatively SWL-resistant; consequently, these stones typically require endoscopic treatment. Moreover, brushite stone formers tend to be highly metabolically active, with high recurrence rates even when patients have been rendered stone free after surgery (1). Therefore, insight into the physicochemical causes of brushite stone formation may facilitate management of these patients, who in my practice constitute a most challenging group of patients to manage medically.Pak and colleagues searched their stone registry to identify 19 patients with predominantly brushite stones and 24 with predominantly hydroxyapatite stones, then compared them with a control group of 762 calcium oxalate stone formers to discern differences in urinary physicochemisty. Brushite stone formers were found to have urine that is significantly more supersaturated with respect to brushite than the other 2 groups, primarily as a result of higher urinary calcium. Indeed, absorptive hypercalciuria was overrepresented in the brushite group (63%) and underrepresented in the hydroxyapatite group (17%) compared with the calcium oxalate group (30%). Not surprisingly, urinary pH was also higher in the brushite and hydroxyapaptite groups than the calcium oxalate group.The authors raised the ques...

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Characterization of intrapelvic pressure during ureteropyeloscopy with ureteral access sheaths

Cited by 254 publications

References 16 publications

Tyrosinase-Inhibitory Long-Chain Esters from Amberboa ramosa

Tyrosinase-Inhibitory Long-Chain Esters from Amberboa ramosa

Retrograde intrarenal surgery for renal stones - Part 1

Stone disease

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