Nucleosome-binding by TP53, TP63, and TP73 is determined by the composition, accessibility, and helical orientation of their binding sites

The p53 family of transcription factors plays key roles in driving development and combating cancer by regulating gene expression. TP53, TP63, and TP73-the three members of the p53 family-regulate gene expression by binding to their DNA binding sites, many of which are situated within nucleosomes. To thoroughly examine the nucleosome-binding abilities of the p53 family, we used Pioneer-seq, a technique that assesses a transcription factor's binding affinity to its DNA binding sites at all possible positions within the nucleosome core particle. Using Pioneer-seq, we analyzed the binding affinity of TP53, TP63, and TP73 to 10 p53-family binding sites across the nucleosome core particle. We found that the affinity of TP53, TP63, and TP73 for nucleosomes was largely determined by the positioning of p53-family binding sites within nucleosomes; p53-family members bind strongly to the more accessible edges of nucleosomes but weakly to the less accessible centers of nucleosomes. We also found that the DNA-helical orientation of p53-family binding sites within nucleosomal DNA impacted the nucleosome-binding affinity of p53-family members. The composition of their binding sites also impacted each p53-family member's nucleosome-binding affinities only when the binding site was located in an accessible location. Taken together, our results show that the accessibility, composition, and helical orientation of p53-family binding sites collectively determine the nucleosome-binding affinities of TP53, TP63, and TP73. These findings help explain the rules underlying p53-family-nucleosome binding and thus provide requisite insight into how we may better control gene-expression changes involved in development and tumor suppression.

Emerging harmful algal blooms caused by distinct seasonal assemblages of a toxic diatom

Diatoms in the Pseudo-nitzschia genus produce the neurotoxin domoic acid. Domoic acid bioaccumulates in shellfish, causing illness in humans and marine animals upon ingestion. In 2017, high domoic acid levels in shellfish meat closed shellfish harvest in Narragansett Bay, Rhode Island for the first and only time in history, although abundant Pseudo-nitzschia have been observed for over 60 years. To investigate whether an environmental factor altered endemic Pseudo-nitzschia physiology or new domoic acid-producing strain(s) were introduced to Narragansett Bay, we conducted weekly sampling from 2017 to 2019 and compared closure samples. Plankton-associated domoic acid was quantified by LC-MS/MS and Pseudo-nitzschia spp. were identified using a taxonomically improved high-throughput rDNA sequencing approach. Comparison with environmental data revealed a detailed understanding of domoic acid dynamics and seasonal multi-species assemblages. Plankton-associated domoic acid was low throughout 2017-2019, but recurred in fall and early summer maxima. Fall domoic acid maxima contained known toxic species as well as a novel Pseudo-nitzschia genotype. Summer domoic acid maxima included fewer species but also known toxin producers. Most 2017 closure samples contained the particularly concerning toxic species, P. australis, which also appeared infrequently during 2017-2019. Recurring Pseudo-nitzschia assemblages were driven by seasonal temperature changes, and plankton-associated domoic acid correlated with low dissolved inorganic nitrogen. Thus, the Narragansett Bay closures were likely caused by both resident assemblages that become toxic depending on nutrient status as well as the episodic introductions of toxic species from oceanographic and climatic shifts.

Randomized Trial of 2 Self-Titrated Oral Appliances for Airway Management

The effectiveness and predictability of 2 different oral appliance (OA) designs to reduce the respiratory event index (REI) in moderate and severe obstructive sleep apnea (OSA) patients requires elucidation. The primary aim of the trial was to determine if 2 widely used midline-traction and bilateral-thrust OA designs differ in effectiveness to reduce the REI within a single test population categorized by OSA severity. Moderate and severe adult OSA patients, who were previously prescribed continuous positive airway pressure therapy (CPAP) but were dissatisfied with it (n = 56), were studied by home-polygraphy in a randomized crossover trial using either midline-traction with restricted mouth opening (MR) or bilateral thrust with opening permitted (BP) design OAs. OAs were used nightly for 4 wk (T2) followed by a 1-wk washout period, then 4 wk (T4) using the alternate OA. REI and oxygen saturation (SaO₂) were primary outcomes, while predictability and efficacy comparison of the 2 OAs were secondary outcomes. Thirty-six participants had used MR and BP OAs during both 4-wk study legs. Twenty (55.6%) MR OA-using participants, 25 (69.4%) BP OA-using participants, and 16 (44.4%) participants using both OAs had significant REI reductions. Overall baseline (T0) median REI (interquartile range) of 33.7 (20.7-54.9) was reduced to 18.0 (8.5-19.4) at T2 and to 12.5 (8.2-15.9) at T4 (P < 0.001). Comparison of the 2 sequence groups' (MR-BP and BP-MR) REI showed the median differences between T0 and T2 and T4 were highly significant (P < 0.001). Regression analysis predicted about half of all users will have REIs between 8 and 16 after 2 mo. Baseline overjet measures >2.9 mm predicted greater OA advancement at T4. Mean and minimum SaO₂ did not change significantly from T0 to T2 or T4. MR and BP OA designs similarly attenuated REI in moderate and severe OSA individuals who completed the 8-wk study protocol with greater REI reduction in those with severe OSA (ClinicalTrials.gov NCT03219034).

Twelve-year follow-up of conservative management of postnatal urinary and faecal incontinence and prolapse outcomes: randomised controlled trial

OBJECTIVE

To determine the long-term (12-year) effects of a conservative nurse-led intervention for postnatal urinary incontinence.

DESIGN

Follow-up of a randomised controlled trial.

SETTING

Community-based intervention in three centres (in the UK and New Zealand).

POPULATION

A cohort of 747 women with urinary incontinence at 3 months after childbirth, of whom 471 (63%) were followed up after 12 years.

METHODS

Women were randomly allocated to active conservative treatment after delivery (pelvic floor muscle training and bladder training), or to a control group receiving standard care.

MAIN OUTCOME MEASURES

Prevalence of urinary incontinence (primary outcome) and faecal incontinence, symptoms and signs of prolapse, and performance of pelvic floor muscle training at 12 years.

RESULTS

The significant improvements relative to controls that had been found in urinary incontinence (60 versus 69%; risk difference, RD, -9.1%; 95% confidence interval, 95% CI, -17.3 to -1.0%) and faecal incontinence (4 versus 11%; RD -6.1%; 95% CI -10.8 to -1.6%) at 1 year did not persist for urinary incontinence (83 versus 80%; RD 2.1%; 95% CI -4.9 to 9.1%) or faecal incontinence (19 versus 15%; RD 4.3%; 95% CI -2.5 to 11.0%) at the 12-year follow up, irrespective of incontinence severity at trial entry. The prevalence of prolapse symptoms or objectively measured pelvic organ prolapse also did not differ between the groups. In the short term the intervention motivated more women to perform pelvic floor muscle training (83 versus 55%), but this fell in both groups by 12 years (52 versus 49%).

CONCLUSIONS

The moderate short-term benefits of a brief nurse-led conservative treatment for postnatal urinary incontinence did not persist. About four-fifths of women with urinary incontinence 3 months after childbirth still had this problem 12 years later.

Diffusion-weighted and multiphase contrast-enhanced MRI as surrogate markers of response to neoadjuvant sunitinib in metastatic renal cell carcinoma

BACKGROUND

Current imaging criteria for categorising disease response in metastatic renal cell carcinoma (mRCC) correlate poorly with overall survival (OS) in patients on anti-angiogenic therapies. We prospectively assess diffusion-weighted and multiphase contrast-enhanced (MCE) MR imaging (MRI) as markers of outcome.

METHODS

Treatment-naive mRCC patients on a phase II trial using sunitinib completed an MRI substudy. Whole-tumour apparent diffusion coefficient (ADC) maps and histograms were generated, and mean ADC and AUC(low) (proportion of the tumour with ADC values lying below the 25th percentile of the ADC histogram) recorded. On MCE-MRI, regions of interest were drawn around the most avidly enhancing components to analyse enhancement parameters. Baseline (n=26) and treatment-related changes in surviving patients (n=20) were correlated with OS. Imaged metastases were also analysed.

RESULTS

Forty-seven per cent of the patients showed significant changes in whole-tumour mean ADC following therapy, but there was no correlation with outcome. Patients with a high baseline AUC(low) and greater-than-median AUC(low) increase had reduced OS (HR=3.67 (95% confidence interval (CI)=1.23-10.9), P=0.012 and HR=3.72 (95% CI=0.98-14.21), P=0.038, respectively). There was no correlation between MCE-MRI parameters and OS. Twenty-eight metastases were analysed and showed positive correlation with primary tumour mean ADC for individual patients (r=0.607; P<0.001).

CONCLUSION

Primary RCC ADC histogram analysis shows dynamic changes with sunitinib. Patients in whom the tumour ADC histogram demonstrated high baseline AUC(low) or a greater-than-median increase in AUC(low) with treatment had reduced OS.

Surveillance results of depleted uranium-exposed Gulf War I veterans: sixteen years of follow-up

As part of a longitudinal surveillance program, 35 members of a larger cohort of 77 Gulf War I veterans who were victims of depleted uranium (DU) "friendly fire" during combat underwent a 3-day clinical assessment at the Baltimore Veterans Administration Medical Center (VAMC). The assessment included a detailed medical history, exposure history, physical examination, and laboratory studies. Spot and 24-h urine collections were obtained for renal function parameters and for urine uranium (U) measures. Blood U measures were also performed. Urine U excretion was significantly associated with DU retained shrapnel burden (8.821 mug U/g creatinine [creat.] vs. 0.005 mug U/g creat., p = .04). Blood as a U sampling matrix revealed satisfactory results for measures of total U with a high correlation with urine U results (r = .84) when urine U concentrations were >/=0.1 mug/g creatinine. However, isotopic results in blood detected DU in only half of the subcohort who had isotopic signatures for DU detectable in urine. After stratifying the cohort based on urine U concentration, the high-U group showed a trend toward higher concentrations of urine beta(2) microglobulin compared to the low-U group (81.7 v. 69.0 mug/g creat.; p = .11 respectively) and retinol binding protein (48.1 vs. 31.0 mug/g creat.; p = .07 respectively). Bone metabolism parameters showed only subtle differences between groups. Sixteen years after first exposure, this cohort continues to excrete elevated concentrations of urine U as a function of DU shrapnel burden. Although subtle trends emerge in renal proximal tubular function and bone formation, the cohort exhibits few clinically significant U-related health effects.

Health surveillance of Gulf War I veterans exposed to depleted uranium: updating the cohort

A cohort of seventy-four 1991 Gulf War soldiers with known exposure to depleted uranium (DU) resulting from their involvement in friendly-fire incidents with DU munitions is being followed by the Baltimore Veterans Affairs Medical Center. Biennial medical surveillance visits designed to identify uranium-related changes in health have been conducted since 1993. On-going systemic exposure to DU in veterans with embedded metal fragments is indicated by elevated urine uranium (U) excretion at concentrations up to 1,000-fold higher than that seen in the normal population. Health outcome results from the subcohort of this group of veterans attending the 2005 surveillance visit were examined based on two measures of U exposure. As in previous years, current U exposure is measured by determining urine U concentration at the time of their surveillance visit. A cumulative measure of U exposure was also calculated based on each veteran's past urine U concentrations since first exposure in 1991. Using either exposure metric, results continued to show no evidence of clinically significant DU-related health effects. Urine concentrations of retinol binding protein (RBP), a biomarker of renal proximal tubule function, were not significantly different between the low vs. high U groups based on either the current or cumulative exposure metric. Continued evidence of a weak genotoxic effect from the on-going DU exposure as measured at the HPRT (hypoxanthine-guanine phosphoribosyl transferase) locus and suggested by the fluorescent in-situ hybridization (FISH) results in peripheral blood recommends the need for continued surveillance of this population.

Laparoscopic colposuspension for urinary incontinence in women

BACKGROUND

Laparoscopic colposuspension was one of the first minimal access operations for the treatment of women with stress urinary incontinence, with the presumed advantages over traditional Burch colposuspension of avoiding major incisions, shorter hospital stay, and quicker return to normal activities. A variety of approaches and methods are used.

OBJECTIVES

To determine the effects of laparoscopic colposuspension for urinary incontinence.

SEARCH STRATEGY

We searched the Cochrane Incontinence Group Specialised Trials Register (searched 21 September 2005). Additional trials were sought from other sources such as reference lists, reviews and researchers and authors were contacted for unpublished data and trials.

SELECTION CRITERIA

Randomised or quasi-randomised controlled trials in women with symptomatic or urodynamic diagnosis of stress or mixed incontinence that included laparoscopic surgery in at least one arm of the study.

DATA COLLECTION AND ANALYSIS

Trials were evaluated for methodological quality and appropriateness for inclusion by the reviewers. Data were extracted by two of the reviewers and cross checked by another. Trial data were analysed by intervention. Where appropriate, a summary statistic was calculated.

MAIN RESULTS

Twenty-one eligible trials were identified. Nine involved the comparison of laparoscopic with open colposuspension. Whilst the women's subjective impression of cure seemed similar for both procedures in the short and medium term follow-up, there was some evidence of poorer results of laparoscopic colposuspension, within 18 months, on objective outcomes. Two poor quality trials reported conflicting long term results (after five years) for this comparison. No significant differences were observed for post-operative urgency, voiding dysfunction or de novo detrusor overactivity. Trends were shown towards a lower perioperative complication rate, longer operating time, less intraoperative blood loss, less postoperative pain, shorter hospital stay, quicker return to normal activities, and shorter duration of catheterisation for laparoscopic compared with open colposuspension. Benefits did not come without a price, as laparoscopic colposuspension in the short term is more costly.Eight studies compared laparoscopic colposuspension with newer 'self-fixing' vaginal slings. Overall there were no significant differences in the reported subjective cure rates of the two procedures, however vaginal sling procedures did have significantly higher objective cure rates at 18 months. No significant differences were observed for post-operative voiding dysfunction, de novo detrusor activity and perioperative complications. Laparoscopic colposuspension has a significantly longer operation time, longer hospital stay and slower return to normal activities when compared to the sling procedures. Significantly higher subjective and objective (dry on 'ultrashort' pad test) one year cure rates were found for women randomised to two paravaginal sutures compared with one suture in a single trial (89% versus 65% and 83% versus 58% respectively). Two small studies compared sutures with mesh and staples for laparoscopic colposuspension and the comparisons, although showing a trend towards favouring the sutures, were not significant. One study compared transperitoneal with extraperitoneal access for laparoscopic colposuspension but it was also small and of poor quality.

AUTHORS' CONCLUSIONS

The long-term performance of laparoscopic colposuspension remains uncertain. Currently available evidence suggests that it may be as good as open colposuspension at two years post surgery. Like other laparoscopically performed operations, patients having laparoscopic colposuspension recovered quicker, but the operation itself took longer to perform. However, the newer vaginal sling procedures appear to offer even greater benefits of minimal access surgery and better objective outcomes in the short-term. If laparoscopic colposuspension is performed, two paravaginal sutures appear to be more effective than one. The place of laparoscopic colposuspension in clinical practice should become clearer when ongoing trials are reported and when there are more data available describing long-term cure results.

New postnatal urinary incontinence: obstetric and other risk factors in primiparae

OBJECTIVE

To identify obstetric and other risk factors for urinary incontinence that occurs during pregnancy or after childbirth.

DESIGN

Questionnaire survey of women.

SETTING

Maternity units in Aberdeen (Scotland), Birmingham (England) and Dunedin (New Zealand).

POPULATION

A total of 3405 primiparous women with singleton births delivered during 1 year.

METHODS

Questionnaire responses and obstetric case note data were analysed using multivariate analysis to identify associations with urinary incontinence.

MAIN OUTCOME MEASURES

Urinary incontinence at 3 months after delivery first starting in pregnancy or after birth.

RESULTS

The prevalence of urinary incontinence was 29%. New incontinence first beginning after delivery was associated with older maternal age (oldest versus youngest group, OR 2.02, 95% CI 1.35-3.02) and method of delivery (caesarean section versus spontaneous vaginal delivery, OR 0.28, 95% CI 0.19-0.41). There were no significant associations with forceps delivery (OR 1.18, 95% CI 0.92-1.51) or vacuum delivery (OR 1.16, 95% CI 0.83-1.63). Incontinence first occurring during pregnancy and still present at 3 months was associated with higher maternal body mass index (BMI>25, OR 1.68, 95% CI 1.16-2.43) and heavier babies (birthweight in top quartile, OR 1.56, 95% CI 1.12-2.19). In these women, caesarean section was associated with less incontinence (OR 0.39, 95% CI 0.27-0.58) but incontinence was not associated with age.

CONCLUSIONS

Women have less urinary incontinence after a first delivery by caesarean section whether or not that first starts during pregnancy. Older maternal age was associated with new postnatal incontinence, and higher BMI and heavier babies with incontinence first starting during pregnancy. The effect of further deliveries may modify these findings.

Childbirth and pelvic floor trauma

The issue of traumatic damage to the pelvic floor in childbirth is attracting more and more attention amongst obstetric caregivers and laypersons alike. This is partly due to the fact that elective caesarean section as a potentially preventative intervention is increasingly available and perceived as safe. As there is a multitude of emotive issues involved, including health economics and the relative roles of healthcare providers, the discussion surrounding pelvic floor trauma in childbirth has not always been completely rational. However, after 25 years of urogynaecological research in this field it should be possible to determine whether pelvic floor trauma in childbirth is myth or reality, and, if real, whether it matters for the pathogenesis of incontinence and prolapse. On reviewing the available evidence, it appears that there are sufficient grounds to assume that vaginal delivery (or even the attempt at vaginal delivery) can cause damage to the pudendal nerve, the inferior aspects of the levator ani muscle and fascial pelvic organ supports. Risk factors for such damage have been defined and variously include operative vaginal delivery, a long second stage, and macrosomia. It is much less clear, however, whether such trauma is clinically relevant, and how important it is in the aetiology of pelvic floor morbidity later in life.

Relationships between hoof-acceleration patterns of galloping horses and dynamic properties of the track

OBJECTIVE

To define relationships between hoof-acceleration patterns of galloping horses and dynamic properties of the track.

ANIMALS

8 Thoroughbred horses without lameness.

PROCEDURE

Acceleration-time curves were recorded by use of accelerometers attached to each hoof as each horse galloped over the track straightaway. Four sessions were conducted for each horse, with the track surface modified by sequentially adding water before each session. These acceleration-time curves were analyzed to determine peak accelerations during the support phase of the stride. Track dynamic properties (hardness, rebound, deceleration rate, rebound rate, and penetration) were recorded with a track-testing device. Moisture content and dry density were measured from soil samples. Stepwise multiple regression was used to identify relationships between hoof-acceleration variables and track dynamic properties.

RESULTS

Track rebound rate was most consistently related to hoof variables, especially through an inverse relationship with negative acceleration peaks for all hooves. Also, rebound rate was related to initial acceleration peak during propulsion of the hooves of the forelimb and the nonlead hind limb as well as to the second acceleration peak during propulsion of the lead hooves of the hind limb and nonlead forelimb.

CONCLUSIONS AND CLINICAL RELEVANCE

The inverse relationship between track rebound rate and negative acceleration peaks for all hooves reflects the most important dynamic property of a track. Any factor that reduces negative acceleration of the hooves will increase stride efficiency by allowing smoother transition from retardation to propulsion and therefore may be important in determining the safety of racing surfaces.

Age-Dependent Telomere Attrition as a Potential Indicator of Racial Differences in Renal Growth Patterns

BACKGROUND

Racial differences in the predilection to salt sensitivity may arise from different renal growth patterns. To test this idea, we monitored age-dependent telomere attrition rate, reflecting largely the replicative history of somatic cells, in the outer renal cortex and the inner renal medulla of African Americans and Caucasians.

METHODS

Telomere length, determined by the mean length of the terminal restriction fragments (TRF), was measured in specimens from 58 African-American and 63 Caucasian males, ages 1 day to 71 years.

RESULTS

In the outer renal cortex, TRF length attrition rate was significantly slower in African Americans (-0.021 +/- 0.0064 kb/year) than in Caucasians (-0.060 +/- 0.0094 kb/year) (p = 0.0007). In both ethnic groups the TRF length attrition rate was slower in the inner medulla than in the outer renal cortex, but without significant racial differences.

CONCLUSIONS

The proximal tubule is the most abundant nephron structure in the outer renal cortex. Less proliferative growth of proximal tubular cells in kidneys from African Americans may be one factor explaining the slower age-dependent telomere attrition rate in the outer renal cortex of African Americans than in Caucasians.

Laparoscopic colposuspension versus urethropexy: a case-control series

Laparoscopic colposuspension (LC) was first described in the early 1990s as a technique distinct from open Burch colposuspension. Subsequently, however, LC was closely modelled along the lines of the Burch technique, and the distinct features of the original urethropexy (UP) were largely disregarded. In this case-control series the authors aimed to compare symptoms and anatomical outcomes after standard LC and urethropexy +/- paravaginal repair. The design was a clinical retrospective case-control trial. The setting was the urogynaecology and endogynaecology services of tertiary hospitals. Fifty patients after LC and 50 women after UP surgery, matched for age, body mass index, previous surgery, pre-existing urge incontinence and length of follow-up (1.01 year, range 0.02-3.54 years) for LC and 0.98 years (range 0.06-3.55 years) for UP). Intervention consisted of standardised interview and translabial ultrasound imaging. There were no significant differences for subjective cure of stress incontinence (80% for UP vs. 74% for LC), postoperative urge incontinence, frequency and nocturia. Significantly more UP patients complained of voiding dysfunction (p=0.01). Significant differences were found for urethral rotation, position of the bladder neck on Valsalva and bladder neck descent on Valsalva (all p<0.001). Both procedures were shown to be effective in curing stress incontinence. The incidence of bladder symptoms was comparable, with the exception of voiding difficulty. Significant differences were observed regarding anatomical appearances, with urethropexies showing more recurrent bladder neck hypermobility and cystocele.

TVT and Sparc suburethral slings: a case?control series

Two midurethral slings, TVT and Sparc, are the subject of this case-control series aimed at assessing sling placement, voiding function, bladder symptoms and patient satisfaction. Thirty-seven Sparc and 69 TVT patients were matched for age, body weight, pre-existing urge incontinence, preoperative voiding, concomitant surgery and length of follow-up (mean 0.6, range 0.1-1.5 years). There were no significant differences for subjective cure/improvement, satisfaction or symptoms of incontinence. The clinical stress test was positive in 8/37 Sparc vs 4/69 TVT patients ( p=0.019). The TVT had a more negative effect ( p=0.001) on postoperative voiding. The Sparc was situated more cranially at rest and further from the symphysis pubis, and was more mobile ( p<0.001) on Valsalva. There are significant differences in medium-term outcomes after TVT and Sparc, affecting tape placement, mobility, effect on voiding function and objective stress continence. Patient satisfaction and subjective cure rates seem similar.

The 'iris effect': how two-dimensional and three-dimensional ultrasound can help us understand anti-incontinence procedures

OBJECTIVE

The objective of this prospective, observational study in patients after tension-free vaginal tape (TVT) implantation was to describe the spatial relationship between suburethral sling implants, urethra and bony pelvis with the help of translabial two-dimensional and three-dimensional (3D) ultrasound.

METHODS

A total of 141 women were examined by translabial ultrasound, supine and after voiding. The TVT sling is highly echogenic and easily identified posterior to the urethra. Tape location was described in the mid-sagittal plane relative to bladder neck and inferoposterior symphyseal margin, at rest and on Valsalva maneuver. In a subset of 83 women, 3D volume ultrasound was performed.

RESULTS

The cranial tape margin was situated on average 9.3 mm above and 16.5 mm posterior to the symphyseal margin (Valsalva: 3.9 mm below and 9.6 mm behind the symphysis); the average tape movement on Valsalva was 16 (range, 2-34.2) mm. The distance between tape and inferoposterior symphyseal margin narrowed highly significantly from 20.4 +/- 4.3 mm at rest to 12.9 +/- 3.9 mm on Valsalva (P < 0.001). When a fitted line plot was placed through tape coordinates on an x-y coordinate system, it became evident that tape movement occurs in an arc around the fulcrum of the posterior symphysis pubis. The result is an increasing reduction in the gap between tape and symphysis pubis (termed the 'iris effect'), implying mechanical compression of the urethra.

CONCLUSIONS

The curative effect of the TVT on stress incontinence is likely to be due to mechanical compression of the urethra between implant and symphysis pubis. A large variation in tape location and movement explains its wide margin of clinical safety and efficacy.

The day of discharge after total hip arthroplasty and the achievement of rehabilitation functional milestones: 11-year trends

This is a report on 11 years (1990-2000) of total hip arthroplasty cases and days of discharge from one large city hospital. In 1990, patients stayed an average of 9.7 days after surgery. By 2000, patients stayed only 5.3 days. In general, women stayed longer than men, but this gap had nearly disappeared by 2000. The patients discharged in 2000 achieved fewer functional milestones during their hospital stay than those discharged in 1990.

The genes and proteins associated with poly-cystic kidney diseases

Genetically based polycystic kidney diseases include autosomal dominant (ADPKD) and recessive (ARPKD) polycystic kidney diseases, nephronophthisis and medullary cystic disease. The PKD1 and PKD2 genes responsible for ADPKD and their respective encoded proteins polycystin-1 and polycystin-2 are under intense study and clues are developing as to their function and roles in the disease process. Structure-function analysis suggests that polycystins form multiprotein complexes with focal adhesion and cell-cell adherens junction proteins, which then initiate intracellular signaling events culminating in regulation of transcription of genes controlling proliferation and differentiation. Although less is known about the PKHD-encoded fibrocystin responsible for ARPKD or about the NPH1-encoded nephrocystin responsible for nephronophthisis, it is proposed that they function in the same cellular pathway involving protein-protein interactions, signal transduction and regulation of gene transcription. ADPKD epithelia are more adherent to collagen, less migratory, fail to recruit FAK to polycystin complexes and show aberrant, persistent expression of the fetal genes Erb-B2 and beta2 subunit of NaK-ATPase after birth. It is suggested that the function of the polycystin complex is to act as a key developmental regulator of renal tubule morphogenesis.

The use of perineal ultrasound to quantify levator activity and teach pelvic floor muscle exercises

Perineal ultrasound was used to detect and quantify levator activity by measuring the displacement of the internal urethral meatus against the inferoposterior margin of the symphysis pubis. Women who had previously been instructed in pelvic floor muscle exercises were more likely to contract the levator muscle when asked to do so than were those without previous instruction (P<0.0001). Of the 56 women who were unable to contract the pelvic floor on request, 32 (57%) eventually succeeded with visual ultrasound biofeedback. Pelvic floor muscle assessment and teaching can be used as an adjunct to the ultrasound assessment of urogynecologic patients, requiring at most 5 minutes. It allows quantification of lavator activity and can provide visual biofeedback, which is easily understood and readily accepted by women.

Irritative symptoms after colposuspension: are they due to distortion or overelevation of the anterior vaginal wall and trigone?

Symptoms of bladder irritability are common after incontinence surgery but their cause is unknown. This study tests the hypothesis that irritative symptoms after colposuspension are due to distortion of the trigone. As part of longitudinal follow-up studies, 175 women were examined 6 months to 12 years after either an open or a laparoscopic Burch colposuspension. The main outcome measures were symptoms of bladder irritability (frequency, nocturia and urge incontinence) and ultrasound findings (bladder neck position at rest and on Valsalva, the presence of a colposuspension ridge, ridge depth and ridge distance, and trigonal angle). Two positive associations between ultrasound parameters and symptoms of bladder irritability were observed: urge incontinence was more likely in the presence of bladder neck funneling, and women with nocturia had a higher trigonal angle. Increased distortion of the trigone was associated with a reduced incidence of urge incontinence in the subgroup of patients after laparoscopic colposuspension. The data presented in this study do not support the hypothesis that symptoms of bladder irritability are due to trigonal distortion or overelevation.

Laparoscopic colposuspension for urinary incontinence in women

BACKGROUND

Laparoscopic colposuspension is a relatively new operation for the treatment of women with stress urinary incontinence with the presumed advantages over traditional Burch colposuspension of avoiding major incisions, shorter hospital stay, and quicker return to normal activities. A variety of approaches and methods are used.

OBJECTIVES

To determine the effects of laparoscopic colposuspension surgery on urinary incontinence.

SEARCH STRATEGY

We searched the Cochrane Incontinence Group specialised register. The date of the most recent search was April 2001. Additional trials were sought from other sources such as reference lists, conference proceedings, reviews and unpublished research.

SELECTION CRITERIA

Randomised or quasi-randomised controlled trials in women with symptomatic or urodynamic diagnosis of stress or mixed incontinence that included laparoscopic surgery in at least one arm of the study.

DATA COLLECTION AND ANALYSIS

Trials were evaluated for methodological quality and appropriateness for inclusion by the reviewers. Data were extracted by two of the reviewers and cross checked by another. Trial data were analysed by intervention. Where appropriate, a summary statistic was calculated.

MAIN RESULTS

Eight eligible trials were identified. Five included 233 women receiving a laparoscopic and 254 women an open colposuspension. Whilst the women's subjective impression of cure seemed similar for both procedures up to 18 months there was some evidence of poorer results on objective outcomes. A single trial suggested poorer long-term performance, but this may reflect surgical inexperience of laparoscopic colposuspension. No significant differences were observed for post-operative urgency, voiding dysfunction or de novo detrusor instability. Trends were shown towards a higher complication rate, longer operating time, less intraoperative blood loss, less postoperative pain, shorter hospital stay, quicker return to normal activities, and shorter duration of catheterisation for laparoscopic compared with open colposuspension. Significantly higher subjective and objective (dry on 'ultrashort' pad test) one year cure rates were found for women randomised to two paravaginal sutures compared with one suture in a single trial (89% vs 65% and 83% vs 58% respectively). One study compared sutures with mesh and staples for laparoscopic colposuspension but it was too small to allow a reliable comparison. One study compared transperitoneal with extraperitoneal access for laparoscopic colposuspension but it was also small and of poor quality.

REVIEWER'S CONCLUSIONS

The long-term performance of laparoscopic colposuspension is uncertain. Currently available evidence suggests that it may be poorer than open colposuspension. Like other laparoscopically performed operations, laparoscopic colposuspension leads to a quicker recovery, but takes longer to perform and may be associated with more surgical complications. If it is performed, two paravaginal sutures appear to be more effective than one. The place of laparoscopic colposuspension in clinical practice should become clearer when ongoing trials are reported and when there are more data available describing long-term cure results.

Surveillance of depleted uranium exposed Gulf War veterans: health effects observed in an enlarged "friendly fire" cohort

To determine clinical health effects in a small group of US Gulf War veterans (n = 50) who were victims of depleted uranium (DU) "friendly fire," we performed periodic medical surveillance examinations. We obtained urine uranium determinations, clinical laboratory values, reproductive health measures, neurocognitive assessments, and genotoxicity measures. DU-exposed Gulf War veterans with retained metal shrapnel fragments were excreting elevated levels of urine uranium 8 years after their first exposure (range, 0.018 to 39.1 micrograms/g creatinine for DU-exposed Gulf War veterans with retained fragments vs 0.002 to 0.231 microgram/g creatinine in DU exposed but without fragments). The persistence of the elevated urine uranium suggests ongoing mobilization from the DU fragments and results in chronic systemic exposure. Clinical laboratory outcomes, including renal functioning, were essentially normal. Neurocognitive measures showing subtle differences between high and low uranium exposure groups, seen previously, have since diminished. Sister chromatid exchange frequency, a measure of mutation in peripheral lymphocytes, was related to urine uranium level (6.35 sister chromatid exchanges/cell in the high uranium exposure group vs 5.52 sister chromatid exchanges/cell in the low uranium exposure group; P = 0.03). Observed health effects were related to subtle but biologically plausible perturbations in central nervous system function and a general measure of mutagen exposure. The findings related to uranium's chemical rather than radiologic toxicity. Observations in this group of veterans prompt speculation about the health effects of DU in other exposure scenarios.

Expression of the urate transporter/channel is developmentally regulated in human kidneys

Recombinant protein prepared from cDNA cloned from rat kidney and its human homolog function as urate transporter/channels in lipid bilayers. Using the antibody (anti-uricase) that detected the rat cDNA clone, we now demonstrate that normal human kidneys contain an immunoreactive protein of identical size to that in rat kidney (36-37 kDa), presumably the human urate transporter/channel (hUAT). The amount of hUAT in kidney homogenates increases progressively from 13 wk of gestation to the early postnatal period. During gestation, hUAT expression is confined to the cytoplasm of proximal tubules of Stage III and/or IV nephrons. However, at 1 yr of age hUAT is primarily located subapically and within brush borders of proximal tubules. Xenopus laevis oocytes and differentiated A6 cells injected with cRNA and transfected with cDNA of hUAT, respectively, demonstrated a similar pattern: hUAT is not detected in oocytes but is abundantly expressed in cytoplasm and plasma membranes of A6 cells. These data imply that different developmental factors regulate the initiation of cytoplasmic hUAT expression and subsequent insertion into human proximal tubule brush-border membranes.

Conservative management of persistent postnatal urinary and faecal incontinence: randomised controlled trial

OBJECTIVES

To assess the effect of nurse assessment with reinforcement of pelvic floor muscle training exercises and bladder training compared with standard management among women with persistent incontinence three months postnatally.

DESIGN

Randomised controlled trial with nine months' follow up.

SETTING

Community intervention in three centres (Dunedin, New Zealand; Birmingham; Aberdeen).

PARTICIPANTS

747 women with urinary incontinence three months postnatally, allocated at random to intervention (371) or control (376) groups.

INTERVENTION

Assessment by nurses of urinary incontinence with conservative advice on pelvic floor exercises at five, seven, and nine months after delivery supplemented with bladder training if appropriate at seven and nine months.

MAIN OUTCOME MEASURES

Primary: persistence and severity of urinary incontinence 12 months after delivery. Secondary: performance of pelvic floor exercises, change in coexisting faecal incontinence, wellbeing, anxiety, and depression.

RESULTS

Women in the intervention group had significantly less urinary incontinence: 167/279 (59.9%) v 169/245 (69.0%), difference 9.1% (95% confidence interval 1.0% to 17.3%, P=0.037) for any incontinence and 55/279 (19.7%) v 78/245 (31.8%), difference 12.1% (4.7% to 19.6%, P=0.002) for severe incontinence. Faecal incontinence was also less common: 12/273 (4.4%) v 25/237 (10.5%), difference 6.1% (1.6% to 10.8%, P=0.012). At 12 months women in the intervention group were more likely to be performing pelvic floor exercises (218/278 (79%) v 118/244 (48%), P<0.001).

CONCLUSIONS

A third of women may have some urinary incontinence three months after childbirth. Conservative management provided by nurses seems to reduce the likelihood of urinary and coexisting faecal incontinence persisting 12 months postpartum. Further trials for faecal incontinence are needed.

Maternal diabetes: an independent risk factor for major cardiovascular malformations with increased mortality of affected infants

BACKGROUND

Intensive medical care of women with diabetes has reduced their risks of bearing infants with congenital anomalies. To assess the preventive potential of preconceptional care, the data of a population-based study of cardiovascular malformations (CVM) were analyzed to determine the morphogenetic specificity of maternal diabetes risks, the morbidity and mortality of the infants, and maternal characteristics that might affect these risks.

METHODS

The Baltimore-Washington Infant Study was a case-control study (1981-1989) that included all live born infants with confirmed CVM; control infants were a representative sample of the birth cohort. A questionnaire administered in home visits recorded parental information on social, medical, occupational, and environmental factors. For these analyses of preconceptional diabetes risks, the case group excluded chromosomal and mendelian disorders and was divided into 3 developmental categories and 12 diagnostic groups.

RESULTS

Preconceptional maternal diabetes was strongly associated with CVM of early embryonic origin (odds ratio [OR] = 4.7, 95% confidence interval [CI] 2.8-7.9) and with cardiomyopathy (OR = 15.1, 95% CI 5.5-41.3), but not with obstructive and shunting defects (OR = 1.4, 95% CI 0.7-3.0). There was heterogeneity within these developmental categories: among laterality defects, diabetes was associated only with cardiovisceral and atrioventricular discordance (OR = 10.0, 95% CI 3.7-27.0); among outflow tract anomalies, the risk was strongly associated with normally related great arteries (OR = 6.6, 95% CI 3.2-13.3) but not with simple transpositions; and among atrioventricular septal defects, diabetes was associated with the complete but not with the partial forms (OR = 22.8, 95% CI 7.4-70.5). The association in early CVM was strongest among infants with multisystem, predominantly VACTERL, anomalies. All-cause mortality of infants with CVM was 39% among those with diabetic mothers and 17.8% in those with nondiabetic mothers. Deceased infants of diabetic mothers were also more likely to have extracardiac anomalies (P = 0.041), to be born prematurely (P = 0.007), and to have low birth weight (P = 0.011). Multivariate analyses of maternal factors revealed no significant confounders of the diabetes associations.

CONCLUSIONS

The evidence of diabetes-induced major cardiac defects is of urgent clinical significance. The effectiveness of early preconceptional care in the prevention of congenital anomalies has been demonstrated repeatedly.

Obstetric practice and faecal incontinence three months after delivery

OBJECTIVE

To determine whether obstetric and maternal factors relate to faecal incontinence at three months postpartum.

SETTING

Maternity units in Aberdeen (Scotland), Birmingham (England) and Dunedin (New Zealand).

POPULATION

All women who delivered during one year in the three maternity units.

METHODS

Postal questionnaire at three months postpartum, to obtain information on faecal incontinence, linked to obstetric casenote data.

MAIN OUTCOME MEASURES

Prevalence of faecal incontinence.

RESULTS

7879 questionnaires were returned, a 71.7% response rate. The prevalence of faecal incontinence was 9.6%, with 4.2% reporting this more often than rarely. Logistic regression, confined to primiparae, showed that forceps delivery was a predictor of an increased risk of symptoms (OR = 1.94, 95% CI 1.30 to 2.89) while vacuum extraction was not associated. Caesarean section was marginally associated with a reduced risk (OR = 0.58, 95% CI 0.35 to 0.97). Older maternal age, Indian sub-continent ethnic origin and body mass index 'not known' also showed significant associations. No associations were found for induced labour, duration of second stage labour, episiotomy, laceration or birthweight.

CONCLUSIONS

Women delivered by forceps had almost twice the risk of developing faecal incontinence, whereas vacuum extraction was not associated with faecal incontinence at three months postpartum. Caesarean section appears to offer some protection.

Radiology of total hip replacements

The early and late roentgenograms of the first 100 consecutive Charnley low friction arthroplasties, performed at the Hospital for Special Surgery from October 1968 to October 1970 demonstrate interesting reactions of joint structure. Osteoporosis, early breakage of the wires and trochanteric bed covered by cement were the main factors preventing or delaying the healing of the osteotomy of the greater trochanter. Almost all hips showed a radiolucent line at the acetabular bone-cement junction and about half at the femoral junction. One-third of the hips had increased femoral cortical thickness. Four hips had sterile loosening of the femoral component with a varus shift. Though about one-third of the hips had some ectopic ossification, in only 3 hips was it severe enough to adversely affect the end result. The use of radiopaque cement seems advantageous over the radiolucent type. Arthrography has proven useful for the diagnosis of complications, particularly if subtraction technique is employed.

Atrioventricular septal defects: possible etiologic differences between complete and partial defects

BACKGROUND

Recent advances in clinical, pathological, and genetic aspects of atrioventricular septal defects (AVSD) have set the stage for epidemiologic investigations into possible risk factors. Previous analyses of the total case group of AVSD included complete and partial subtypes without analysis of the subsets.

METHODS

To address the question of possible morphogenetic heterogeneity of AVSD, the Baltimore-Washington Infant Study data on live-born cases and controls (1981-1989) was reanalyzed for potential environmental and genetic risk-factor associations in complete AVSD (n = 213), with separate comparisons to the atrial (n = 75) and the ventricular (n = 32) forms of partial AVSD.

RESULTS

Complete and ventricular forms of AVSD had a similar proportion of isolated cases (12.2% and 15.6%, respectively, without associated extracardiac anomalies) and high rates of Down syndrome, whereas the atrial form of partial AVSD included 55% isolated cases. Trisomy 18 occurred in 22% of infants with the ventricular form, compared with <2% in the other AVSD groups. Analysis of potential risk factors revealed further distinctions. Complete AVSD as an isolated cardiac defect was strongly associated with maternal diabetes (odds ratio [OR] = 20.6; 95% confidence interval [CI] =5.6-76.4) and also with antitussive use (OR = 8.8; CI = 1.2-48.2); there were no strong associations other than maternal age among Down syndrome infants with this type of heart defect. Isolated cases with the atrial type of partial AVSD were associated with a family history of heart defects (OR = 6.2; CI = 1.4-24.4) and with paternal occupational exposures to ionizing radiation (OR = 5.1; CI = 1.4-27.4), but no risk factors were associated with Down syndrome. There were no significant associations of any risk factors in the numerically small subsets of isolated and Down syndrome cases with the ventricular form of partial AVSD.

CONCLUSIONS

These results indicate a similar risk profile of complete AVSD and the ventricular type of partial AVSD, with a possible subset of the latter due to trisomy 18. Maternal diabetes constituted a potentially preventable risk factor for the most severe, complete form of AVSD.

Modification of the composition of polycystin-1 multiprotein complexes by calcium and tyrosine phosphorylation

Mutations in the PKD1 gene are responsible for >85% of autosomal dominant polycystic kidney disease (ADPKD). The protein product of PKD1, polycystin-1, is a large, modular membrane protein, with putative ligand-binding motifs in the extracelluar N-terminal portion, 9-11 transmembrane domains and an intracellular C-terminal portion with phosphorylation sites. A role for polycystin-1 as a cell surface receptor involved in cell-matrix and cell-cell interactions has been proposed. In this study, we have analyzed polycystin-1 and associated protein distribution in normal human epithelial cells and examined the role of cell-matrix versus cell-cell interactions in regulation of the assembly of polycystin-1 multiprotein complexes. Immunocytochemistry, sucrose density gradient sedimentation, co-immunoprecipitation analyses and in vitro binding assays have shown that polycystin-1 associates with the focal adhesion proteins talin, vinculin, p130Cas, FAK, alpha-actinin, paxillin and pp60c-src in subconfluent normal human fetal collecting tubule (HFCT) epithelia when cell-matrix interactions predominate. Polycystin-1 also forms higher S value complexes with the cell-cell adherens junction proteins E-cadherin, beta- and gamma-catenins in confluent cultures when cell-cell interactions are predominant. Polycystin-1 multiprotein complexes can be disrupted by cytochalasin D but not by colchicine, suggesting involvement of the actin cytoskeleton. Although inhibition of tyrosine phosphorylation by tyrphostin inhibits polycystin-1-FAK interactions, E-cadherin interactions are enhanced. High calcium treatment also increases polycystin-1-E-cadherin interactions.

Colposuspension success and failure: a long-term objective follow-up study

The Burch colposuspension is regarded as one of the most successful procedures for the operative treatment of genuine stress incontinence. In this study the authors have attempted to define long-term subjective and objective success rates. Of 121 patients operated on between 1985 and 1995, 83 were fully assessed: 77% (64/83) had no stress leakage, but 41% (34/83) were suffering from urge incontinence. On clinical assessment 6 cases of uterine prolapse or vault descent, 21 cystoceles (25%) and 47 rectoceles or rectoenteroceles (57%) were detected, all but 8 being asymptomatic. On ultrasound 64/83 patients (77%) had a normal result. Ten patients demonstrated bladder neck hypermobility and in 9 there was urethral funneling without hypermobility. Survival analysis showed that the likelihood of all types of failure and of abnormal ultrasound findings increased over time. It is proposed that long-term results after incontinence surgery be presented as survival analysis.

Development of a three-centre simultaneous objective structured clinical examination

OBJECTIVE

To describe the development, organization, implementation and evaluation of a yearly multicentre, identical and simultaneous objective structured clinical examination (OSCE).

SUBJECTS

All fifth-year medical students in a 6-year undergraduate medical programme.

SETTING

The Christchurch, Dunedin and Wellington Schools of Medicine of the University of Otago, New Zealand.

METHOD

One practice and two full 18-station OSCEs have been completed over 2 years, for up to 72 students per centre, in three centres. The process of development and logistics is described. Data are presented on validity, reliability and fairness.

RESULTS

Face and content validity were established. Internal consistency was 0.83-0. 86 and interexaminer reliability, as assessed by the coefficient of correlation, averaged 0.78. Students rated the OSCE highly on relevance. Of the total variance in total OSCE marks, the schools contributed 6.9%, and the students 93.1%, in the first year. In the second year the schools contributed 6.2% and the students 93.8%.

CONCLUSION

Implementation of a psychometrically sound, multicentre, simultaneous and identical OSCE is possible with a low level of interschool variation.

Microgradients in bacterial colonies: use of fluorescence ratio imaging, a non-invasive technique

Fluorescence ratio imaging is a non-invasive technique for studying the formation of microgradients in immobilised bacterial colonies. These gradients can be quantified easily when combined with the gel cassette system designed at the Institute of Food Research, Norwich, UK. Colonies of Lactobacillus curvatus were observed using this technique and relevant pH gradients were present when the colonies reached a diameter of about 100 microm. These pH gradients were due to production of lactic acid by L. curvatus cells in the colonies. The spatial resolution of the images was about 1.5 microm (scale of bacterial cells) and therefore very suitable for observing local effects in colonies which ranged in sizes from 1 to 500 microm.

Monomeric midkine induces tumor cell proliferation in the absence of cell-surface proteoglycan binding

Midkine (MK), a retinoic acid-inducible heparin-binding protein, is a mitogen which initiates a cascade of intracellular protein tyrosine phosphorylation mediated by the JAK/STAT pathway after binding to its high affinity p200(+)/MKR cell surface receptor in the G401 cell line [Ratovitski, E. A. (1998) J. Biol. Chem. 273, 3654-3660]. In this study, we determined the biophysical characteristics of purified recombinant murine MK and analyzed the requirements for ligand multimerization and cell surface proteoglycan binding for the G401 cell mitogenic activity of MK. Our studies indicate that the secreted form of MK (M = 13 kDa) exists in solution as an asymmetric monomer with a frictional coefficient of 1. 48 and a Stokes radius of 23.7 A. By constructing bead models of MK using the program AtoB and the program HYDRO to predict the hydrodynamic properties of each model, our data suggest that MK has a dumb-bell shape in solution composed of independent N- and C-terminal domains separated by an extended linker. This asymmetric MK monomer is a biologically active ligand with mitogenic activity on G401 cells in vitro. Neither heparin-induced formation of noncovalent MK multimers nor tissue transglutaminase II covalent multimerization of MK enhanced MK mitogenic activity in this system. Since neither heparin competition nor cell treatment with chondroitinase ABC or heparinase III abolished the mitogenic effects of MK on G401 cells, cell-surface proteoglycan binding by MK does not appear to be a requirement for its observed mitogenic effects. These results provide strong evidence that the MK-specific p200(+)/MKR has distinctive biochemical properties which distinguish it from the receptor tyrosine phosphatase cell-surface proteoglycan PTPzeta/RPTPbeta and support the hypothesis that the diverse biological effects of MK are mediated by multiple cell-specific signal transduction receptors.

Hospital for special surgery. A brief review of its development and current position

On May 1, 1999, the Hospital for Special Surgery was 136 years old. To present a history that does adequate justice to the many people, who have been or still are involved in the making of it, is an impossible task. Nevertheless, this document is important because the hospital, first under the name of Ruptured and Crippled and then under that of Special Surgery has played such an important role in the development of orthopaedics and rheumatology in America during the past century. The reader must forgive an orthopaedic bias to this account and also realize the limitation of space that makes it at best fragmentary and incomplete. The account begins with a description of the hospital's current situation, physical layout and governance. A terse history of the hospital's origin and subsequent development follows, which includes a more specific description of the growth of its orthopaedic surgical services. Finally, separate records of the 112-year-old Postgraduate Orthopaedic Educational Program and 44-year-old Research Division are presented.

Interrupted aortic arch: an epidemiologic study

BACKGROUND

Interruption of the aortic arch (IAA) is a rare but severe anomaly associated with major intracardiac defects and with multisystem noncardiac malformations, recently linked to chromosome deletion of 22q11.2.

METHODS

The Baltimore-Washington Infant Study (1981-1989), a population-based epidemiologic study of cardiovascular malformations, evaluated 53 infants with IAA in comparison with 3,572 controls. Risk factors for the anatomic subtypes were evaluated in 14 cases of IAA type A and 32 cases of IAA type B, but no molecular genetic tests were available. The distribution of associated cardiac defects was similar for both types.

RESULTS

DiGeorge syndrome (DGS) occurred more frequently in IAA type B. Case-control comparisons demonstrated that infants in both groups were growth retarded at birth. A family history of noncardiac defects occurred only in IAA type B cases and included relatives with cleft lip and/or cleft palate. Candidate risk factors were associated only in type B cases and differed for those with (n = 10) and for those without (n = 19) DGS: a family history of noncardiac defects (odds ratio [OR] = 7.2, 95% confidence interval [CI] = 1.5-39.2) and maternal use of aspirin during the critical period (OR = 4.8, 95% CI = 1.3-25.4) occurred with DGS, while previous stillbirth (OR = 9.4, 95% CI = 1.3-53.1), bleeding during pregnancy (OR = 3.7, 95% CI = 1.4-11.4), and maternal exposure to arts/crafts paints (OR = 4.8, 95% CI = 1.3-17.4) were associated in those without DGS.

CONCLUSIONS

These findings confirm the heterogeneity of IAA and of the type B subtype. Risk factors specific for cases with DGS may open a window to further investigations of the etiology of IAA and of the associated molecular genetic abnormalities.

Formation of 20-hydroxyeicosatetraenoic acid, a vasoactive and natriuretic eicosanoid, in human kidney. Role of Cyp4F2 and Cyp4A11

20-hydroxyeicosatetraenoic acid (20-HETE), an omega-hydroxylated arachidonic acid (AA) metabolite, elicits specific effects on kidney vascular and tubular function that, in turn, influence blood pressure control. The human kidney's capacity to convert AA to 20-HETE is unclear, however, as is the underlying P450 catalyst. Microsomes from human kidney cortex were found to convert AA to a single major product, namely 20-HETE, but failed to catalyze AA epoxygenation and midchain hydroxylation. Despite the monophasic nature of renal AA omega-hydroxylation kinetics, immunochemical studies revealed participation of two P450s, CYP4F2 and CYP4A11, since antibodies to these enzymes inhibited 20-HETE formation by 65. 9 +/- 17 and 32.5 +/- 14%, respectively. Western blotting confirmed abundant expression of these CYP4 proteins in human kidney and revealed that other AA-oxidizing P450s, including CYP2C8, CYP2C9, and CYP2E1, were not expressed. Immunocytochemistry showed CYP4F2 and CYP4A11 expression in only the S2 and S3 segments of proximal tubules in cortex and outer medulla. Our results demonstrate that CYP4F2 and CYP4A11 underlie conversion of AA to 20-HETE, a natriuretic and vasoactive eicosanoid, in human kidney. Considering their proximal tubular localization, these P450 enzymes may partake in pivotal renal functions, including the regulation of salt and water balance, and arterial blood pressure itself.

Primary total hip replacement with a noncemented acetabular component: minimum 5-year clinical follow-up

The results of 123 total hip replacements with a noncemented Harris-Galante I acetabular component were reviewed (minimum 5-year clinical follow-up). The average clinical follow-up was 7 years (range, 5-10.8 years). No acetabular components were revised for loosening. One cup was revised for recurrent dislocation. In 3 cases, the acetabular liner was replaced at the time of femoral component revision (aseptic loosening), and in 1 case, a liner was revised because of recurrent dislocations. Of the hips, 92 had a complete set of radiographs for analysis. None of the acetabular components had migrated. Of the 92 acetabular components, 90 were considered radiographically stable (98%). Of these hips, 24 had linear radiolucencies of < or =2 mm in < or =2 of 4 zones and were considered stable. Two cups (2%) were considered possibly unstable. One of these had a linear radiolucent line in 3 zones, and the other had an osteolytic lesion measuring 6 x 11 mm in greatest dimensions. No acetabular components were definitely unstable. The average Harris Hip Score improved from 50 points (range, 17-89 points) preoperatively to 95 points (range, 74-99 points) at the latest follow-up examination. The average Hospital for Special Surgery hip score improved from 21 points (range, 10-31 points) preoperatively to 38 points (range, 27-40) at the last follow-up examination. Noncemented acetabular fixation with the Harris-Galante I component showed excellent clinical results at a minimum of 5 years' follow-up.

Apical plasma membrane mispolarization of NaK-ATPase in polycystic kidney disease epithelia is associated with aberrant expression of the beta2 isoform

Autosomal dominant polycystic kidney disease (ADPKD) is a common genetic disease of the kidney, characterized by cystic enlargement of renal tubules, aberrant epithelial proliferation, and ion and fluid secretion into the lumen. Previous studies have shown abnormalities in polarization of membrane proteins, including mislocalization of the NaK-ATPase to the apical plasma membranes of cystic epithelia. Apically located NaK-ATPase has previously been shown to be fully functional in vivo and in membrane-grown ADPKD epithelial cells in vitro, where basal-to-apical (22)Na transport was inhibited by application of ouabain to the apical membrane compartment. Studies were conducted with polymerase chain reaction-generated specific riboprobes and polyclonal peptide antibodies against human sequences of alpha1, alpha3, beta1, and beta2 subunits of NaK-ATPase. High levels of expression of alpha1 and beta1 messenger RNA were detected in ADPKD and age-matched normal adult kidneys in vivo, whereas beta2 messenger RNA was detected only in ADPKD kidneys. Western blot analysis and immunocytochemical studies showed that, in normal adult kidneys, peptide subunit-specific antibodies against alpha1 and beta1 localized to the basolateral membranes of normal renal tubules, predominantly thick ascending limbs of Henle's loop. In ADPKD kidneys, alpha1 and beta2 subunits were localized to the apical epithelial cell membranes, whereas beta1 was distributed throughout the cytoplasm and predominantly in the endoplasmic reticulum, but was not seen associated with cystic epithelial cell membranes or in cell membrane fractions. Polarizing, renal-derived epithelial Madin Darby canine kidney cells, stably expressing normal or N-terminally truncated chicken beta1 subunits, showed selective accumulation in the basolateral Madin Darby canine kidney cell surface, whereas c-myc epitope-tagged chicken beta2 or human beta2 subunits accumulated selectively in the apical cell surface. Similarly, human ADPKD epithelial cell lines, which endogenously expressed alpha1 and beta2 NaK-ATPase subunits, showed colocalization at the apical cell surface and coassociation by immunoprecipitation analysis. These results are consistent with a model in which the additional transcription and translation of the beta2 subunit of NaK-ATPase may result in the apical mislocalization of NaK-ATPase in ADPKD cystic epithelia.

The PKD1 gene product, "polycystin-1," is a tyrosine-phosphorylated protein that colocalizes with alpha2beta1-integrin in focal clusters in adherent renal epithelia

Mutations in the PKD1 gene are responsible for autosomal dominant polycystic kidney disease (ADPKD). Although PKD1 has been cloned and shown to be expressed at high levels in the fetal ureteric bud and ADPKD cystic epithelia in the human kidney, the function of its encoded protein, "polycystin-1" is unknown. In this study we used primary and immortalized human renal epithelial cell lines derived from normal fetal, adult, and ADPKD kidneys, that endogenously express PKD1, to study the biologic function of the polycystin-1 protein. ADPKD renal epithelial cells expressed high levels of polycystin-1 protein and showed increased adhesion to type I collagen by comparison with normal adult human renal epithelia that expressed little polycystin. Adherent ADPKD cells also expressed high levels of alpha2beta1-integrin and their attachment was inhibited by a functional monoclonal antibody to alpha2-integrin. Double labeling and confocal microscopy as well as coimmunoprecipitation analysis showed overlapping colocalization of polycystin-1 with alpha2beta1-integrin as well as with the focal adhesion proteins vinculin and paxillin in multiprotein clusters localized to focal areas of cell membrane contact with type I collagen matrix after short periods of attachment. Immunoprecipitation and Western immunoblot studies also showed that polycystin-1 was posttranslationally modified by tyrosine phosphorylation. These studies suggest that the PKD1-encoded protein is part of a large multiprotein complex in epithelial cells that functions in the regulation of extracellular matrix interactions with the plasma membrane and cell cytoskeleton.

Transduction of renal cells in vitro and in vivo by adeno-associated virus gene therapy vectors

There has been an increasing interest recently in the possibility of treating renal diseases using gene therapy. The ability to pursue gene therapy for renal diseases has been limited by the availability of an adequate system for gene delivery to the kidney. Adeno-associated virus (AAV) is a defective virus of the parvovirus family that has a number of properties attractive for renal gene delivery: recombinant AAV contains no viral genes; expression of genes delivered by these vectors does not activate cell-mediated immunity; the virus is able to transduce nondividing as well as dividing cells; and both wild-type and recombinant AAV integrate into the host chromosome resulting in long-term gene expression. Studies were performed to determine whether AAV can deliver reporter genes to kidney cells in vitro and in vivo. These studies show that AAV can deliver reporter genes with approximately equal efficiency to human mesangial, proximal tubule, thick ascending limb, collecting tubule, and renal cell carcinoma cells in primary culture. Immortalized mouse mesangial cells are transduced at a much greater efficiency. Transduction can be enhanced by pharmaceutical agents up to sevenfold in primary cells (transducing up to 20% of primary cells per well) and as much as 400-fold in immortalized mesangial cells. AAV delivered in vivo by intraparenchymal injection results in at least 3 mo of reporter gene expression in tubular epithelial, but not glomerular or vascular, cells at the injection site. These data indicate that AAV can deliver genes to renal cells both in vitro and in vivo resulting in prolonged gene expression, and thus AAV can be a useful tool for renal gene delivery.