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At least 127 records · Page 7Linked to original sources
PubMed1995

Complete duplication of the ureter with ureteropelvic junction obstruction of the lower pole of the kidney: imaging findings.

OBJECTIVE: The purpose of our study was to identify the radiographic signs that aid in the diagnosis of obstruction of the ureteropelvic junction of the lower pole (or moiety) of the kidney in children with complete duplication of the ureter and to describe the imaging appearance of this unusual cause of lower-pole hydronephrosis. MATERIALS AND METHODS: We reviewed the medical records and imaging studies of 16 children (11 boys and five girls) with complete ureteral duplication and ureteropelvic junction obstruction of the lower pole of the kidney over a 5-year period. standard criteria for determining urinary tract obstruction were used. RESULTS: Sonograms showed a lower-pole abnormality (hydronephrosis or cystic mass) in all 15 children who underwent sonography. Voiding cystourethrography, performed for all children, showed vesicoureteral reflux into the lower pole in addition to ureteropelvic junction obstruction in eight children (seven boys and one girl). For the other eight, the diagnosis of lower-pole ureteropelvic junction obstruction was made by excretory urography, at times complemented with diuretic renography or retrograde ureterography. CONCLUSION: Ureteropelvic junction obstruction of the lower pole of the kidney in children with complete duplication of the ureter should be a diagnostic consideration when there is dilatation of the lower moiety. Imaging changes parallel those of ureteropelvic junction obstruction in a nonduplicated system. This anomaly, unlike others seen in duplication, appears to be more common in boys than in girls.

Child↗
PubMedDate not supplied

The predictive value of posterior pole vessels in retinopathy of prematurity.

Dilation and tortuosity of the posterior pole vessels "(plus disease)" is a sign of poor prognosis and may be associated with threshold or prethreshold retinopathy of prematurity (ROP). We have found that normal posterior pole vessels are a reliable marker for the absence of stage 3 ROP. One hundred thirty-two consecutive premature infants weighing less than 1600 g at birth underwent ROP examinations between 32 and 40 weeks' postconceptional age. The status of the posterior pole vessels was compared to peripheral retinal pathology. Vascular findings in the posterior pole were graded 0, 1, 2, or 3, with 0 representing normal arterioles and venules and 3 representing plus disease. The remainder of the fundus examination was recorded using the international Classification of ROP, then converted to a severity scale based on zone and stage of ROP. For each infant, only one examination representing the most severe stage of ROP reached prior to treatment or spontaneous regression was used for data analysis. There was a highly significant Spearman's rank correlation (rs = 0.65) between the posterior pole vascular abnormalities and the severity of ROP in the retinal periphery. Clinically important ROP was not found in any patient with normal posterior pole vessels (grade 0) and stage 3 disease was usually associated with both venous and arterial vascular abnormalities (grades 2 or 3). When ocular examination of premature infants is difficult because of poor dilation of the pupil, hazy media, or medical instability, normal appearance of the posterior pole vessels can be a reassuring finding if it is necessary to postpone complete fundus examination in infants at risk for ROP.

Fundus Oculi↗
PubMedDate not supplied

Subtotal splenectomy preserving the lower pole in rats: technical, morphological and functional aspects.

PURPOSE: To assess the possibility of preserving the lower pole of the spleen, supplied by the inferior lobar vessels and segmental vessels, or by vessels of the gastrosplenic ligament, in subtotal splenectomy; to study the viability and function of the lower pole of the spleen. METHODS: Thirty-six male Wistar rats were used in this study. Said animals weighed 273-390 g ( 355.2 +/- 30.5 g ), and were randomly distributed into three groups. Group 1 comprised ten animals which were submitted to exploratory laparotomy with spleen manipulation (sham operation). Group 2 comprised 16 animals which were submitted to total splenectomy. Group 3 comprised ten animals which were submitted to subtotal splenectomy, preserving the lower pole of the spleen. Blood was collected from all animals before and 90 days after surgery to measure the levels of cholesterol and triglycerides. The animals were sacrificed 90 days after surgery. Spleens and remaining spleens were removed for macroscopic and microscopic examination. RESULTS: Surgery was performed with no complications in all groups. Six animals died in group 2. Spleens of groups 1 and 2, and lower poles of group 3 were macroscopically viable. Apparent white pulp hyperplasia was observed in group 1. In group 3, slight inflammation and capsular fibrosis were observed at the incision site, as well as diffuse hemosiderosis in the red pulp. Average mass of remaining spleen was 35.84% +/- 4.31%. No significant difference was observed between preoperative and late postoperative lipid levels in groups 1 and 3 (p > 0.05). Late postoperative lipid levels significantly increased in group 2. CONCLUSIONS: Preservation of the lower pole of the spleen (supplied by gastrosplenic vessels or inferior lobar vessels and segmental vessels) was possible with subtotal splenectomy. The lower pole was macroscopically and microscopically viable in all cases. Subtotal splenectomy preserving the lower pole prevented changes in lipid levels, which were observed in rats submitted to total splenectomy. Plasma lipid levels in rats submitted to subtotal splenectomy were similar to those observed in sham operated rats.

Animals↗
PubMedDate not supplied

[Behavior of the mitotic apparatus after ultraviolet microirradiation of the spindle pole].

UV-microirradiation of the centrosome (spindle pole) alters behaviour of mitotic cell. Cell reaction strongly depends on the stage of mitosis when irradiation has been made. Irradiation of one pole at metaphase blocked cell in c-mitosis for several hours. The same or even more strong irradiation of the pole at anaphase slightly postponed cytokinesis, but didn't prevent chromosome separation and normal exit of cell into interphase. Irradiation at metaphase resulted in immediate shift of chromosomes towards the nonirradiated pole. Afterwards spindle disassembled. Irradiation at anaphase slowed down chromosome motion towards irradiated pole without prominent effect on the opposite halfspindle. Electron microscopy demonstrated that immediately after irradiation centrosome lost association with kinetochore microtubules. At metaphase irradiated pole moved towards chromosomes, while at anaphase--away from them. Same irradiation of other besides spindle poles regions had no effect on continuation of mitosis.

Animals↗
PubMed2004

Drosophila tudor is essential for polar granule assembly and pole cell specification, but not for posterior patterning.

Pole cells and posterior segmentation in Drosophila are specified by maternally encoded genes whose products accumulate at the posterior pole of the oocyte. Among these genes is tudor (tud). Progeny of hypomorphic tud mothers lack pole cells and have variable posterior patterning defects. We have isolated a null allele to further investigate tud function. While no pole cells are ever observed in embryos from tud-null mothers, 15% of these embryos have normal posterior patterning. OSKAR (OSK) and VASA (VAS) proteins, and nanos (nos) RNA, all initially localize to the pole plasm of tud-null oocytes and embryos from tud-null mothers, while localization of germ cell-less (gcl) and polar granule component (pgc), is undetectable or severely reduced. In embryos from tud-null mothers, polar granules are greatly reduced in number, size, and electron density. Thus, tud is dispensable for somatic patterning, but essential for pole cell specification and polar granule formation.

Animals↗
PubMed2004

Effects of 20-s and 180-s double poling interval training in cross-country skiers.

The purpose of this study was to investigate the effect of upper body 20-s or 180-s interval training, using a double poling ergometer, on upper body power output and selected physiological and biomechanical parameters in cross-country skiers. Twenty (12 male, 8 female) well-trained cross-country skiers took part. Two intervention groups, a 20-s interval training group (IT20; n=6) and a 180-s interval training group (IT180; n=7), underwent training three times a week for 6 weeks on a double poling ergometer. A third group served as a control (CON; n=7) and followed the same training program as the IT20 and IT180 groups without the double poling ergometer interval training. The IT20 and IT180 groups significantly (P<0.05) increased both peak and mean power in a 30-s test and mean power in a 6-min test after double poling training. There was a significant improvement in work efficiency in both IT20 and IT180 (P<0.05) and, in IT180, a significant reduction (P<0.05) in blood lactate concentration at given sub-maximal workloads. VO(2peak) increased significantly during double poling in IT180 ( P<0.05) only. VO(2max) did not change significantly in either group. There were no significant changes in any of the test variables in CON. In conclusion, this study shows that 6 weeks of 20-s or 180-s double poling interval training, three times a week, significantly increases power output in both 30-s and 6-min tests, as well as in selected physiological and biomechanical parameters in well-trained cross-country skiers.

Adult↗
PubMed1986

Abdominal segmentation, pole cell formation, and embryonic polarity require the localized activity of oskar, a maternal gene in Drosophila.

Embryos derived from oskar females lack pole cells and the specialized pole plasm including polar granules. In addition, the abdominal region remains unsegmented and eventually dies. Transplantation of cytoplasm from normal embryos into mutant embryos reveals that osk-dependent activity is strictly localized at the posterior pole and has three distinct functions. In mutant embryos the activity will normalize pole cell formation when transplanted into the posterior pole and abdominal segmentation after transplantation to a more anterior, the prospective abdominal, region. Furthermore, osk activity can provoke the formation of a second "posterior center" at the anterior. The participation of the osk product in the establishment of a source of morphogenetic activity in the posterior pole plasm is discussed.

Abdomen↗
PubMed2004

Reduction of posterior pole retinal thickness in glaucoma detected using the Retinal Thickness Analyzer.

OBJECTIVES: To report evidence of changes in posterior pole retinal thickness in glaucoma and preperimetric glaucoma. DESIGN: Cross-sectional study. PARTICIPANTS: One hundred forty participants (140 eyes): 31 normal subjects, 33 with ocular hypertension, 43 with primary open-angle glaucoma (POAG), and 33 with preperimetric glaucoma. INTERVENTION: Posterior pole retinal thickness measurements using the Retinal Thickness Analyzer (RTA; Talia Technology Ltd., Neve-Ilan, Israel). MAIN OUTCOME MEASURES: The mean foveola average thickness (VAV), foveola minimum thickness (VMI), perifoveal average thickness (PFAV), perifoveal minimum thickness (PFMI), posterior pole average thickness (PPAV), and posterior pole minimum thickness (PPMI) were compared among the groups. The correlation between RTA values and visual field values was evaluated. The area under the receiver operator characteristic (AROC) curve, the optimal cut values, and the predictability values were estimated statistically between normal and the other groups using RTA values. RESULTS: Results from 91 eyes (65%) were included. Perifoveal average thickness values in preperimetric glaucoma (190.4+/-15.6 microm; mean+/-standard deviation) and POAG (185.7+/-16.8 microm) were significantly less than in normal controls (211.4+/-16.8 microm) and in eyes with ocular hypertension (211.6+/-15.9 microm). Perifoveal minimum thickness, PPAV, and PPMI were significantly less in preperimetric glaucoma and in POAG than in normal controls; VAV and VMI were not significantly different among groups. Perifoveal average thickness, PFMI, PPAV, and PPMI significantly correlated with visual field mean defect (R = -0.38, -0.42, -0.36, and -0.41, respectively) and loss of variance (R = -0.29, -0.30, -0.26, and -0.17, respectively). The AROC using PFAV, PFMI, PPAV, and PPMI was significantly larger than 0.5 between normal and preperimetric glaucoma (0.83, 0.92, 0.82, and 0.87, respectively) and between normal and POAG eyes (0.86, 0.97, 0.83, and 0.93, respectively). When using the PFMI, the sensitivities at the minimum specificity cutoffs of 90% were highest in comparisons between normal and preperimetric glaucoma (sensitivity, 75%) and between normal and POAG eyes (sensitivity, 95%). By the logistic regression analysis, PFAV, PFMI, PPAV, and PPMI distinguished between normal and preperimetric glaucoma (R(2) = 0.30, 0.49, 0.27, and 0.37, respectively) and between normal and POAG (R(2) = 0.37, 0.59, 0.31, and 0.51, respectively). CONCLUSIONS: Posterior pole retinal thickness decreases in early- and moderate-stage glaucoma. Reduction of perifoveal retinal thickness is correlated with visual field loss. In vivo measurements of posterior pole retinal thickness may help distinguish between normal and glaucomatous eyes.

Adult↗
PubMed2002

Predictors of lower pole renal stone clearance after extracorporeal shock wave lithotripsy.

PURPOSE: Lower pole renal stones are well known to show a poor stone clearance rate after extracorporeal shock wave lithotripsy (ESWL) (Dornier Medical Systems, Marietta, Georgia). In the current study we analyzed several anatomical factors as predictors of lower pole stone clearance that may be used to indicate the usefulness of ESWL in such patients. MATERIALS AND METHODS: Between January 1993 and October 2000, 63 patients with a unilateral single lower pole stone of 2 cm. or less were included in the study. Excretory urography was done to determine the lower infundibulopelvic angle, caliceal pelvic height, lower infundibular length and diameter, lower infundibular length-to-diameter ratio and number of lower pole minor calices. Stone-free status was assessed by x-ray. RESULTS: The overall stone clearance rate was 54% (34 of 63 patients). While caliceal pelvic height, lower infundibular diameter, length, length-to-diameter ratio and number of minor calices were different in the stone-free and residual stone groups on univariate analysis, multivariate logistic analysis revealed that the lower infundibular length-to-diameter ratio, diameter and number of minor calices were independent predictors of successful stone clearance. The 13 patients (20.6%) who showed all 3 favorable anatomical factors (lower infundibular length-to-diameter ratio less than 7, diameter greater than 4 mm. and a single minor calix) achieved an impressive 84.6% stone clearance rate. In patients with only 1 or 2 favorable factors the stone clearance rate was still greater than 60%. In contrast, the stone clearance rate was only 6.7% in the 15 patients who showed none of these factors. CONCLUSIONS: From this study it is apparent that successful ESWL is highly sensitive to the anatomy of the lower pole of the kidney. If a patient with a lower pole stone has at least 1 of the favorable factors identified in this study, ESWL may be advocated as first line therapy with a greater than 60% prospect of a successful outcome. Other treatment options should be considered in those without any of these predictive factors.

Adult↗
PubMed1999

Retrograde ureteropyeloscopy for lower pole caliceal calculi.

PURPOSE: Contemporary treatment of lower pole renal calculi includes extracorporeal shock wave lithotripsy, percutaneous nephrostolithotomy and retrograde ureteropyeloscopy. Success rates for shock wave lithotripsy are reduced in this setting, especially for stones greater than 1 cm. and/or in patients with anatomical variants. Percutaneous treatment, although effective, subjects the patient to increased morbidity. We studied the safety and efficacy of retrograde ureteroscopic treatment of lower pole intrarenal calculi. MATERIALS AND METHODS: We evaluated 90 stone burdens localized to the lower pole and treated with a small diameter, actively deflectable, flexible ureteropyeloscope and a 200 micron holmium laser fiber. Stone burdens were classified as group 1--10 or less, group 2--11 to 20 and group 3--greater than 20 mm. in largest diameter. Patients with calculi less than 2.5 cm. were treated as outpatients unless concurrent medical conditions required hospitalization. Larger stones and partial staghorn calculi (group 3) frequently required 2-stage endoscopic procedures with retrograde intrarenal irrigation for 36 hours to clear debris. An acceptable immediate surgical outcome was defined as complete fragmentation reducing the stone burden to dust and 2 mm. or less fragments. Success was defined as clear imaging (that is stone-free) on renal sonography with minimum 3-month followup. Extreme anatomical variants, including a long infundibulum, acute infundibulopelvic angle and a dilated collecting system, were noted and correlated with surgical failures. RESULTS: Endoscopic access and complete stone fragmentation were achieved in 94, 95 and 45% of groups 1, 2 and 3, respectively. After a second treatment the success rate increased to 82% in group 3, with an overall rate of 91%. Of the 19 surgical failures 8 were secondary to inability to access the lower pole and 11 were secondary to inability to render the patient stone-free. In 2 of the 19 cases infundibular strictures hindered ureteroscopic access. In addition, of the anatomical variants a long lower pole infundibulum was the most statistically significant predictor of failure. Mean operative time ranged from 38 minutes for small to 126 for the largest calculi. There were no major complications. Overall stone-free rates with minimum 3-month followup were 82, 71 and 65% in groups 1, 2 and 3, respectively, and 88, 77 and 81%, respectively, in patients with an acceptable initial surgical outcome (that is excluding those with access failures from analysis). CONCLUSIONS: Retrograde ureteropyeloscopy is a safe and effective surgical treatment for lower pole intrarenal calculi.

Adolescent↗
PubMed2002

Long-term outcome of the retained ureteral stump after lower pole heminephrectomy in duplex kidneys.

OBJECTIVES: Duplication of the ureter and renal pelvis is the most common upper urinary tract anomaly in childhood. The anatomical and functional divisions between upper and lower moieties of duplex kidney are extremely variable. The underlying pathological condition associated with a lower moiety is usually massive vesicoureteral reflux (VUR) to the lower collecting system and only rare obstruction. The non-functioning upper moiety is usually associated with obstructive ectopic ureter (with or without ureterocele). Most lower pole heminephrectomies are carried out for non-functioning lower moieties. In most cases, the lower defunctionalised segment of the ureter is left in situ. Complete ureterectomy is usually performed if presence of VUR into the lower end of the corresponding ureter is shown. There is little information on the long-term outcome of residual ureteral 'stumps'. The purpose of our study was to review the long-term outcome of retained ureteral stumps in children undergoing heminephrectomy for non-functioning lower pole moieties in duplex kidneys. MATERIALS AND METHODS: The medical records of 19 patients who underwent 20 lower pole heminephrectomies for a non-functioning lower pole moiety of a duplex kidney between January 1990 and December 2000 were reviewed retrospectively. Median age at heminephrectomy was 4.5 years (range: 1 month to 12 years). Indications for heminephrectomy in the 20 renal units was reflux nephropathy in 16 (80%) and obstructive nephropathy in 4 (20%). All corresponding ureters were taken down as low as possible and transfixed through the heminephrectomy incision. Median follow-up was 8.5 years (range: 1-11 years). RESULTS: Eight (40%) showed VUR into the stump after lower pole heminephrectomy. Two of these underwent subureteral endoscopic correction of VUR with polytetrafluoroethylene paste and resection of the stump was carried out in remaining two patients for recurrent urinary tract infections (UTI). Remaining four of the eight patients demonstrated spontaneous resolution of VUR during follow-up. CONCLUSIONS: Our data suggest that the vast majority of patients with residual ureteral stumps after lower pole heminephrectomy do not require stump resection at long-term follow-up.

Child↗
PubMed1999

Optic nerve head sector analysis recognizes glaucoma most effectively around disc poles.

PURPOSE: To analyze the topography of normal and glaucomatous discs with the goal of developing improved strategies to discriminate between normal and glaucomatous eyes. SUBJECTS AND METHODS: Raster tomography was performed in both eyes of 225 healthy subjects and in 296 eyes of 214 glaucoma patients. Cup area, average cup radius, rim area and minimal rim width were measured in 24 sectors around the optic nerve head at nine different depths from the reference plane. Receiver Operating Curves (ROC) for numerous combinations of parameter, sector and depth were calculated and compared. RESULTS: Discrimination between glaucomatous and normal eyes varied widely between single sectors of the optic disc, and was best at the vertical poles of the disc, intermediate in nasal sectors and worst in temporal sectors. When single sectors or combinations of sectors at the superior pole were combined with their counterparts at the inferior pole of the optic nerve, the gain in sensitivity exceeded the loss in specificity, and discrimination improved. Separation declined dramatically if any of the 8 temporal sectors were involved in such analysis. Depth influenced discrimination only slightly. CONCLUSION: Single sectors located close to the vertical meridian yielded better discrimination than global measurements. When two or more sectors at the superior pole were combined with each other, as well as with their counterparts at the inferior pole, discrimination improved even further. Localized changes concurred frequently, but asymmetrically at both poles of the disc. The depth from reference plane used to define the cup was not critical for separation between normal and glaucomatous eyes.

Adult↗
PubMed1999

The unipolar Shigella surface protein IcsA is targeted directly to the bacterial old pole: IcsP cleavage of IcsA occurs over the entire bacterial surface.

Shigella flexneri is an intracellular pathogen that is able to move within the cytoplasm of infected cells by the continual assembly of actin onto one pole of the bacterium. IcsA, an outer membrane protein, is localized to the old pole of the bacterium and is both necessary and sufficient for actin assembly. IcsA is slowly cleaved from the bacterial surface by the protease IcsP (SopA). Absence of IcsP leads to an alteration in the distribution of surface IcsA, such that the polar cap is maintained and some IcsA is distributed along the lateral walls of the bacillus. The mechanism of unipolar localization of IcsA and the role of IcsP in its unipolar localization are incompletely understood. Here, we demonstrate that cleavage of IcsA occurs exclusively in the outer membrane and that IcsP is localized to the outer membrane. In addition, we show that IcsA at the old pole is susceptible to cleavage by IcsP and that native IcsP is active at the pole. Taken together, these data indicate that IcsP cleaves IcsA over the entire bacterial surface. Finally, we show that, immediately after induction from a tightly regulated promoter, IcsA is expressed exclusively at the old pole in both the icsP- icsA- and the icsA- background. These data demonstrate that unipolar localization of IcsA results from its direct targeting to the pole, followed by its diffusion laterally in the outer membrane.

Actins↗
PubMed2004

The spindle pole body assembly component mps3p/nep98p functions in sister chromatid cohesion.

For successful chromosome segregation during mitosis, several processes must occur early in the cell cycle, including spindle pole duplication, DNA replication, and the establishment of cohesion between nascent sister chromatids. Spindle pole body duplication begins in G1 and continues during early S-phase as spindle pole bodies mature and start to separate. Key steps in spindle pole body duplication are the sequential recruitment of Cdc31p and Spc42p by the nuclear envelope transmembrane protein Msp3p/Nep98p (herein termed Mps3p). Concurrent with DNA replication, Ctf7p/Eco1p (herein termed Ctf7p) ensures that nascent sister chromatids are paired together, identifying the products of replication as sister chromatids. Here, we provide the first evidence that the nuclear envelope spindle pole body assembly component Mps3p performs a function critical to sister chromatid cohesion. Mps3p was identified as interacting with Ctf7p from a genome-wide two-hybrid screen, and the physical interaction was confirmed by both in vivo (co-immunoprecipitation) and in vitro (GST pull-down) assays. An in vivo cohesion assay on new mps3/nep98 alleles revealed that loss of Mps3p results in precocious sister chromatid separation and that Mps3p functions after G1, coincident with Ctf7p. Mps3p is not required for cohesion during mitosis, revealing that Mps3p functions in cohesion establishment and not maintenance. Mutated Mps3p that results in cohesion defects no longer binds to Ctf7p in vitro, demonstrating that the interaction between Mps3p and Ctf7p is physiologically relevant. In support of this model, mps3 ctf7 double mutant cells exhibit conditional synthetic lethality. These findings document a new role for Mps3p in sister chromatid cohesion and provide novel insights into the mechanism by which a spindle pole body component, when mutated, contributes to aneuploidy.

Acetyltransferases↗
PubMed1999

Knee joint forces during downhill walking with hiking poles.

The aim of this study was to determine external and internal loads on the knee joint during downhill walking with and without hiking poles. Kinematic, kinetic and electromyographic data were collected from eight males during downhill walking on a ramp declined at 25 degrees. Planar knee joint moments and forces were calculated using a quasi-static knee model. The results were analysed for an entire pole-cycle as well as differentiated between single and double support phases and between each step of a pole-cycle. Significant differences between downhill walking with and without hiking poles were observed for peak and average magnitudes of ground reaction force, knee joint moment, and tibiofemoral compressive and shear forces (12-25%). Similar reductions were found in patellofemoral compressive force, the quadriceps tendon force and the activity of the vastus lateralis; however, because of a high variability, these differences were not significant. The reductions seen during downhill walking with hiking poles compared with unsupported downhill walking were caused primarily by the forces applied to the hiking poles and by a change in posture to a more forward leaning position of the upper body, with the effect of reducing the knee moment arm.

Adult↗
PubMed1996

Kinetochores moving away from their associated pole do not exert a significant pushing force on the chromosome.

We used video-light microscopy and laser microsurgery to test the hypothesis that as a bioriented prometaphase chromosome changes position in PtK1 cells, the kinetochore moving away from its associated pole (AP) exerts a pushing force on the centromere. When we rapidly severed congressing chromosomes near the spindle equator between the sister kinetochores, the kinetochore that was originally "leading" the motion towards a pole (P) always (17/17 cells) continued moving P whereas the "trailing" kinetochore moving AP always stopped moving as soon as the operation was completed. This trailing kinetochore then initiated motion towards the pole it was originally moving away from up to 50 s later. The same result was observed (15/15 cells) when we selectively destroyed the leading (P moving) kinetochore on a congressing chromosome positioned > or = 3 microns from the pole it was moving away from. When we conducted this experiment on congressing chromosomes positioned within 3 microns of the pole, the centromere region either stopped moving, before switching into motion towards the near pole (2/4 cells), or it continued to move AP for 30-44 s (2/4 cells) before switching into P motion. Finally, kinetochore-free chromosome fragments, generated in the polar regions of PtK1 spindles, were ejected AP and often towards the spindle equator at approximately 2 microns/min. From these data we conclude that the kinetochore moving AP on a moving chromosome does not exert a significant pushing force on the chromosome. Instead, our results reveal that, when not generating a P force, kinetochores are in a "neutral" state that allows them to remain stationary or to coast AP in response to external forces sufficient to allow their K-fiber to elongate.

Animals↗
PubMed2001

Ureteroscopic management of lower-pole renal calculi: technique of calculus displacement.

PURPOSE: We review our technique of ureteroscopic management of lower pole renal calculi with Nitinol basket displacement and holmium laser stone fragmentation. METHODS: Lower pole calculi are identified with a 7.5F flexible ureteroscope. In patients in whom the laser fiber reduces ureteroscopic deflection, precluding reentry into the lower pole, a Nitinol basket or grasper is used to displace the calculi into an upper pole calix for easier fragmentation. RESULTS: The Nitinol device can be passed into the lower pole through the fully deflected ureteroscope without any loss of deflection. Irrigation is significantly reduced by the basket, but this factor does not impede stone retrieval. CONCLUSIONS: Ureteroscopic management of lower pole stones is a reasonable alternative to SWL or percutaneous nephrolithotomy in low-volume stone disease. If the stone cannot be fragmented in situ, Nitinol basket capture through a fully deflected ureteroscope into a less dependent position facilitates stone fragmentation.

Equipment Design↗
PubMed2003

Laparoscopic upper-pole heminephrectomy for ectopic ureter: surgical technique.

A duplex kidney associated with a poorly functioning upper-pole segment is commonly associated with incontinence, voiding dysfunction, and urinary tract infections. A standard treatment option for this condition is upper-pole heminephrectomy. With the continued development of minimally invasive urology, this technique can now be safely performed laparoscopically. This report details step by step our technique of laparoscopic upper-pole heminephrectomy. Key points include placement of a catheter in the normal ureter at the start of the case, full mobilization of the upper-pole ureter away from the renal hilum, and precise identification of the vasculature supplying the upper pole. Laparoscopic upper-pole heminephrectomy for ectopic ureter is safe and reproducible and offers the patient the typical postoperative benefits of laparoscopic surgery.

Humans↗