Comparing binary & ordinal definitions of urinary & stool continence outcomes: Data from the National Spina Bifida Patient Registry

INTRODUCTION

The National Spina Bifida Patient Registry (NSBPR) assesses bladder and bowel incontinence using ordinal categories, but prior NSBPR analyses employed binary classification. Our aims were to 1) perform the first NSBPR analysis of bladder and bowel incontinence as ordinal outcomes to compare to the binary definition and subject variables; 2) explore the correlation of incontinence with undergarment usage, and 3) assess incontinence status following continence surgeries.

METHODS

Data from NSBPR participants' most recent clinic visit from 2013 to 2020 were analyzed. Ordinal categories of incontinence were compared to previously used binary definitions. Incontinence surgical outcomes were analyzed for those with data at least three months post-operatively. Chi-square tests evaluated associations among categorical variables. Univariate and ordinal logistic regression models were used to test associations of ordinal incontinence status with patient and condition factors. Statistical tests were 2-sided; p values < 0.05 were considered significant.

RESULTS

Analysis of 7217 individuals using ordinal incontinence outcomes showed little difference from previously used binary outcomes. The final multivariable logistic regression models with ordinal multinomial outcomes showed that associations of incontinence with age, sex, race/ethnicity, health insurance, level of lesion, and continence management technique were similar to prior studies. Among those reporting never being incontinent of both bladder and bowel, 14% reported using protective undergarments. Of the 500 individuals who had bladder outlet surgery, 38% reported never being incontinent of urine. Of 1416 individuals who had appendicostomy (ACE) bowel surgery, 48% reported never being incontinent of stool.

DISCUSSION

Our current analysis showed that ordinal continence outcome classification had similar continence findings as previous studies using the binary definition of continence. Expanding the binary definition of continence to include monthly episodes of incontinence did not greatly increase the proportion of continent individuals and, therefore, would have not likely made meaningful differences in continence outcomes in prior NSBPR analyses. However, it is known that even mild incontinence can affect quality of life, therefore, capturing any level of incontiennce is of clinical importance. Confirmation of the association of continence outcomes with sociodemographic, condition-related, and interventional factors with both approaches further validates previous analyses using the binary definition of continence.

CONCLUSION

The previously used binary definition of bladder and bowel continence appears robust. Undergarment choice was a poor surrogate for reported incontinence. After bladder and bowel continence surgeries, 38% and 48%, respectively, reported never being incontinent.

Establishing the first community-centered Spina Bifida research agenda

INTRODUCTION

Spina bifida (SB) is the most common permanently disabling congenital defect. In 2016, the Spina Bifida Association (SBA) began updating the Guidelines for the Care of People with Spina Bifida (Guidelines). These Guidelines identified over 250 research gaps for the care of individuals with SB. The community of people living with SB prioritized these research gaps to create a formal research agenda that the SBA could support.

OBJECTIVE

To present the process and the final research agenda created by individuals with SB, their care partners, clinicians, and researchers.

DESIGN

A quantitative survey was developed to allow adults with SB and caregivers of those with SB to rank the impact of each of the 27 topical areas of the Guidelines. The survey was sent via SBA's database to English and Spanish-literate individuals. 1607 responses were captured and analyzed. Two focus groups were convened after survey analysis: adults with SB and caregivers of children with SB. Discussion outlines for the focus groups were developed based on the results from the survey and were used for known-group validation of the highest-ranked topics. The SBA then solicited caregivers of those with SB, adults with SB, and clinical communities to join its initial Research Advisory Council (RAC). Each group generated a list of top research questions to address the gaps in these highest-ranked impact areas. The SBA led discussion groups for each topic area to rank the proposed questions in order of importance to the SB community. They provided content validity and revisions to the language to improve interpretation by the SB community. The final SB Research Agenda was created from the final four to six ranked questions in each of the six topics.

RESULTS

A ranking of findings from the quantitative survey identified the two most common topics impacting adults with SB and caregivers of both children and adults with SB were bowel incontinence and urinary incontinence.

CONCLUSION

A Research Agenda for SB was rigorously created to prioritize topic areas of highest impact as ranked by individuals in the SB community to fill the research gaps identified in the Guidelines. Bowel and urinary incontinence, both often treated by urologists, were ranked at the top. This agenda will be used to prioritize research efforts to improve the health of those with SB.

COVID-19 vaccination in individuals with spina bifida: A national survey

PURPOSE

This study aimed to conduct a national survey of individuals with spina bifida (SB) and their care partners to assess COVID-19 vaccination behaviors and vaccine uptake.

METHODS

A survey instrument was designed to assess current vaccination status, general perceptions towards vaccinations, and barriers to vaccination within the SB community. Surveys were administered to individuals with SB or their representing care partner. Chi-squared and independent-samples t-tests were used to analyze the relationship between vaccine uptake and demographics. Multivariable logistic regression modeling was used to test which predictors impacted the odds that a participant received a COVID vaccine.

RESULTS

A total of 1,412 participants completed the questionnaire, and 1,145 participants reported their COVID-19 vaccine status. The most common reason for not getting vaccinated was a concern about vaccine safety and efficacy. Overall, healthcare professional recommendations played a significant (OR 2.77 p < 0.001) role in whether to get vaccinated.

CONCLUSION

About one in five individuals with SB have not received any COVID-19 vaccine. Actionable and modifiable factors were identified which may help increase vaccine uptake. Importantly, health providers play a critical role in COVID-19 vaccination messaging and should emphasize vaccine safety and efficacy.

Who is managing the bowels? A survey of clinical practice patterns in spina bifida clinics

PURPOSE

Neurogenic bowel dysfunction (NBD) affects 80% of individuals with spina bifida. Performing and disseminating research on NBD to reach the appropriate audience is difficult given the variability among medical specialties managing NBD. This study aimed to identify which medical specialties and types of providers are currently managing NBD in the United States.

METHODS

A survey was developed and sent to 75 spina bifida clinics. Surveys queried which specialty was primarily responsible for medical and surgical management of NBD and any others that assist in NBD care. The license and certification level of the providers were collected. Descriptive statistics were performed to describe the results.

RESULTS

Response rate was 68%. Urology was the leading specialty primarily responsible for NBD management (39%) followed by rehabilitation medicine and developmental pediatrics (22% and 20%, respectively). Physicians were the primary providers of care followed by nurse practitioners (54% vs 31%). Urology performs 65% of NBD surgeries.

CONCLUSION

Multiple specialties and providers are involved in NBD management with variation among clinics. Development of improved NBD care should include a spectrum of specialties and providers. Dissemination of research should be aimed at multiple specialty groups.

Neurogenic bowel treatments and continence outcomes in children and adults with myelomeningocele

PURPOSE

Neurogenic bowel dysfunction (NBD) is a common comorbidity of myelomeningocele (MMC), the most common and severe form of spina bifida. The National Spina Bifida Patient Registry (NSBPR) is a research collaboration between the CDC and Spina Bifida Clinics. Fecal continence (continence) outcomes for common treatment modalities for NBD have not been described in a large sample of individuals with MMC. NSBPR patients with MMC and NBD were studied to determine variation in continence status and their ability to perform their treatment independently according to treatment modality and individual characteristics.

METHODS

Continence was defined as < 1 episode of incontinence per month. Eleven common treatments were evaluated. Inclusion criteria were established diagnoses of both MMC and NBD, as well as age ⩾ 5 years (n= 3670). Chi-square or exact statistical tests were used for bivariate analyses. Logistic regression models were used to estimate the odds of continence outcomes by age, sex, race/ethnicity, level of motor function, and insurance status.

RESULTS

At total of 3670 members of the NSBPR met inclusion criteria between November 2013 and December 2017. Overall prevalence of continence was 45%. Prevalence ranged from 40-69% across different treatments. Among continent individuals, 60% achieved continence without surgery. Antegrade enemas were the most commonly used treatment and had the highest associated continence rate. Ability to carry out a treatment independently increased with age. Multivariable logistic regression showed significantly higher odds of continence among individuals aged ⩾ 12 years, female, non-Hispanic white, and with private insurance.

Malone Antegrade Continence Enemas vs. Cecostomy vs. Transanal Irrigation-What Is New and How Do We Counsel Our Patients?

PURPOSE OF REVIEW

No gold standard exists for managing neurogenic bowel dysfunction, specifically in individuals with spina bifida. Since the International Children's Continence Society published its consensus document on neurogenic bowel treatment in 2012, an increased focus on why we must manage bowels and how to improve our management has occurred. This review provides updated information for clinicians.

RECENT FINDINGS

A surge in research, mostly retrospective, has been conducted on the success and satisfaction of three types of management for neurogenic bowel. All three management techniques have relatively high success rates for fecal continence and satisfaction rates. Selection of which treatment to carry out still is debated among clinicians. Transanal irrigation is a safe and effective management option for neurogenic bowel that does not require surgery. Antegrade enemas can be carried out via cecostomy tube or Malone antegrade continence enema with similar fecal continence outcomes.

Lower Urinary Tract Symptoms in Older Children With and Without Diabetes Mellitus

Lower urinary tract symptoms (LUTS) are an underrecognized complication of diabetes mellitus (DM) in adults and have undergone limited investigation in children. We estimated the prevalence of LUTS in 120 older children (11-17 years) with and without DM and identified patient factors associated with LUTS in logistic regression. Older children (11-17 years) completed a validated LUTS measure and questions about age, ethnicity, gender, body mass index, and degree of bother secondary to LUTS. The unadjusted prevalence of LUTS was 20.87% in the overall cohort, and LUTS was twice as prevalent in children with DM (33.3% vs 16.7%) than children without DM. In logistic regression, Hispanic/Latino ethnicity was positively associated with LUTS (odds ratio = 8.45, P = .011). LUTS may be a prevalent but underrecognized condition, which is more prevalent in Hispanic/Latino and diabetic children.

Evaluation of spina bifida transitional care practices in the United States

PURPOSE

Recent studies have revealed that the lack of continuity in preparing patients with spina bifida to transition into adult-centered care may have detrimental health consequences. We sought to describe current practices of transitional care services offered at spina bifida clinics in the US.

METHODS

Survey design followed the validated transitional care survey by the National Cystic Fibrosis center. Survey was amended for spina bifida. Face validity was completed. Survey was distributed to registered clinics via the Spina Bifida Association. Results were analyzed via descriptive means.

RESULTS

Total of 34 clinics responded. Over 90 characteristics were analyzed per clinic. The concept of transition is discussed with most patients. Most clinics discuss mobility, bowel and bladder management, weight, and education plans consistently. Most do not routinely evaluate their process or discuss insurance coverage changes with patients. Only 30% communicate with the adult providers. Sexuality, pregnancy and reproductive issues are not readily discussed in most clinics. Overall clinics self-rate themselves as a 5/10 in their ability to provide services for their patients during transition.

CONCLUSIONS

Characteristics of current transitional care services and formal transitional care programs at US clinics show wide variances in what is offered to patients and families.

Home Urodynamic Pressures and Volume Measurement for the Neurogenic Bladder: Initial Validation Study

PURPOSE

We evaluated the ability of a bladder pressure/volume diary to identify patients at risk for increased intravesical pressures.

MATERIALS AND METHODS

Patients dependent on clean intermittent catheterization used ruler based manometry to measure intravesical pressures before leakage or scheduled drainage at home. We prospectively collected clinical, urodynamic and bladder pressure/volume diary data in patients with spina bifida who were optimized on anticholinergic therapy and clean intermittent catheterization. Measurements were taken with patients in the supine position with relaxed abdominal muscles. We defined increased pressure as detrusor pressure greater than 30 cm water as measured by urodynamics. ROCs were plotted to correlate bladder pressure/volume diary variables with abnormal intravesical pressures, and the most sensitive variable in determining abnormal intravesical pressures was sought as the end point.

RESULTS

A total of 30 patients with a mean age of 10 years (range 1 to 20) were included. Home pressures measured at maximal clean intermittent catheterization volume and mean bladder pressure/volume diary pressures were most reliable in predicting urodynamic pressures greater than 30 cm water (AUC 0.93 and 0.87, respectively). Home pressures measured at maximal clean intermittent catheterization volumes less than 20 cm water were associated with normal bladder pressures (less than 30 cm water) on urodynamics, with a sensitivity of 100% and a specificity of 80%.

CONCLUSIONS

Home manometry less than 20 cm water provides a reliable measurement of safe pressures. A bladder pressure/volume diary is feasible and can aid in monitoring pressures at home without the additional cost and morbidity of urodynamics. A bladder pressure/volume diary may be a useful tool to help identify patients who would benefit from urodynamic testing.

Kelly procedure for exstrophy or epispadias patients: Anatomical description of the pudendal neurovasculature

INTRODUCTION

Adequate penile length in males with bladder exstrophy or epispadias is a major challenge. Kelly previously described a surgical technique of a single stage reconstruction for patients with exstrophy or epispadias that potentially achieves significant penile lengthening by completely detaching the insertion of the corpora cavernosa from the ischiopubic rami. However, because of the possibility of damage to the pudendal neurovascular supply that may lead to partial or complete penile loss, this technique has not gained popularity. The aim of this study is to describe the surgical anatomic relationship of the pudendal neurovascular bundle (NVB) to the ischiopubic rami and to determine a safer approach to dissection during the Kelly procedure.

METHODS

We performed meticulous dissection in three formalin-fixed and one fresh adult male cadavers to demonstrate the anatomical relationships between the pudendal neurovascular supply of the penis and the cavernosal insertion to the ischiopubic ramus.

RESULTS AND DISCUSSION

We demonstrated the relationships and distance between the NVB and the area of separation between the crus and the ischiopubic ramus at the level of the periosteum. The insertion of the crus to the ischiopubic ramus is inferior lateral, whereas the NVB lies at a superior medial position. This anatomical relationship is best visualized when the dissection is carried out starting from the distal portion of the NVB and proceeding proximally. This area of the periosteum is avascular and the NVB can be preserved safely as long as the dissection is conducted at that subperiosteal level. Based on this cadaver dissection study, we suppose that detaching the corporal cavernosa from the pubic bones at the subperiosteal level allows for a safe distance to be maintained from the pudendal nerve at all times. We believe that if a surgeon performs the dissection inferiorly and laterally, the corpora cavernosa can be safely detached from the ischiopubic ramus and injury to the pudendal vessels and nerve can be avoided. However, it must be noted that there are limitations to applying the results from this study of normal, adult cadavers to the anatomy of children and adolescents with exstrophy or epispadias, who form the largest proportion of patients who are candidates for this procedure.

CONCLUSION

This anatomical study demonstrates the relationship between the pudendal NVB, the crus, and the ischiopubic ramus. We demonstrated how the separation of the crus from the ischiopubic periosteum might be performed more safely.

Prospective evaluation of Peristeen® transanal irrigation system with the validated neurogenic bowel dysfunction score sheet in the pediatric population

AIMS

To determine the ability of Peristeen® transanal irrigation system to reduce symptoms of neurogenic bowel dysfunction (NBD) in patients using the validated neurogenic bowel dysfunction scoring system for the pediatric population.

METHODS

Patients 3-21 years with NBD whose current bowel program was unsuccessful were given the Neurogenic Bowel Dysfunction (NBoDS) score sheet before initiating Peristeen®, and at 2 weeks, 2 months, and 6 months after. All patients were started on Peristeen® with tap water (20 ml/kg) per daily irrigation. Mean and paired t-tests were completed.

RESULTS

24 patients were enrolled and had follow-up. Mean age was 10.5 years (range 3-21 years), 25%, 50%, 25% had thoracic, lumbar and sacral level lesions respectively. Mean NBoDS score at initiation of Peristeen® was 20.21 (±5.56), n = 24. The mean score after two weeks of use was 12.75 (±4.40), n = 24. There was a statistically significant decrease of 7.46 (95%CI, 5.07-9.84) points, t(23) = 6.47, P < 0.0005 after two weeks. There was a statistically significant decrease in their scores from initiation to the 2 month time period of 7.00 (95%CI, 2.18-11.82) points, t(9) = 3.29, P = 0.009. By the sixth month of daily use the mean NBoDS score was 9.67 (n = 12). This was an average decrease of 8.83 (95%CI, 5.39-12.28) points from initiation score, t(11) = 5.641, P < 0.005.

CONCLUSION

The Peristeen® transanal irrigation system provides a significant reduction in NBoDS scores in pediatric patients with NBD. Peristeen® should be considered when other conservative bowel management options have been unsuccessful. Neurourol. Urodynam. 36:632-635, 2017. © 2016 Wiley Periodicals, Inc.

Endoscopic correction of vesicoureteral reflux simulator curriculum as an effective teaching tool: Pilot study

INTRODUCTION

It has been well recognized that simulators are effective tools to teach and evaluate technical skills in laparoscopic surgery. Endoscopic injection for the correction of vesicourteral reflux has a definite learning curve. Surgeon experience has also been demonstrated to have an important role in the outcome of the procedure. Simulated training allows for practice in a realistic setting without the inherent risk of harm to the patient. This stress free environment allows the trainee to focus on the acquisition of surgical skills without worry about surgical outcome.

OBJECTIVE

The aim was to validate a porcine bladder simulator curriculum for training and assessment of the surgical skills for the endoscopic correction of vesicoureteral reflux.

STUDY DESIGN

We developed a porcine bladder-based dextranomer/hyaluronic acid (Dx/HA) injection simulator consisting of a dissected ex vivo porcine bladder in a polystyrene box with the distal ureters and urethra secured (Figure). We performed content validation by five experienced pediatric urologists. We then organized a simulator curriculum, which included lecture, demonstration, and a 2-h hands-on training on the simulator. Content, discriminant, and concurrent validation of the simulator curriculum were carried out using 11 urology trainees at different levels of expertise. All the trainees were evaluated for each step of the procedure of both their first and last performances on the simulator.

RESULTS

Overall, the model demonstrated good content validity by all experts (mean questionnaire score 92%). The simulator curriculum demonstrated a significant improvement in the performance of the trainees between their first and last evaluations (56-92%; p = 0.008). Specific parts of the procedure that showed significant improvement (p < 0.05) were identification of the ureteral orifice, ureteral orifice hydrodistention, first and second injection, and location, size, and depth of the mound after injection.

DISCUSSION

The Dx/HA endoscopic injection simulator is an effective training tool to improve the performance of the surgeon carrying out the procedure. This teaching tool may be used to help improve the performance of the surgeon carrying out the procedure. This teaching curriculum may shorten the early learning curve historically associated with the procedure and provide a greater understanding of the technical components of successful endoscopic vesicoureteral reflux correction. Additionally, the implementation of this simulator within the developed curriculum can improve the performance of training urologists in all steps of the challenging technique of Dx/HA needle injection confirming concurrent validity. The next step in evaluation of this surgical skill-training curriculum would be to determine if the improvement in skill performance observed during training translates to improved performance in the clinical realm, or predictive validity.

LIMITATIONS

Some small differences exist between the porcine model and human ureteral orifices. In the porcine model the ureteral orifices are located medially and distally in the bladder neck, which make injection more challenging. Participants suggested that after practicing with the simulator endoscopic injection to a human ureteral orifice would be easier.

CONCLUSION

The simulator curriculum was able to improve the performance of the surgeon carrying out the procedure during subsequent simulations.

Aerosol transfer of bladder urothelial and smooth muscle cells onto demucosalized colonic segments for bladder augmentation: in vivo, long term, and functional pilot study

BACKGROUND

Bladder augmentation technique has changed over the years and the current practice has significant adverse health effects and long-term sequelae. Previously, we reported a novel cell transfer technology for covering demucosalized colonic segments with bladder urothelium and smooth muscle cells through an aerosol spraying of these cells and a fibrin glue mixture.

OBJECTIVE

To determine the long-term durability and functional characteristics of demucosalized segments of colon repopulated with urothelial cells in the bladder of swine for use in augmentation cystoplasty.

STUDY DESIGN

Nine swine were divided into three groups. The first group (control) underwent standard colocystoplasty; the second group underwent colocystoplasty with colonic demucosalization and aerosol application of fibrin glue and urothelial cell mixture; in the third group detrusor cells were added to the mixture described in group two. The animals were kept for 6 months. Absorptive and secretory function was assessed. Bladders were harvested for histological and immunohistochemical evaluation.

RESULTS

All animals but one in the experimental groups showed confluent urothelial coverage of the colonic segment in the bladder without any evidence of fibrosis, inflammation, or regrowth of colonic epithelial cells. Ten percent of the instilled water in the bladder was absorbed within an hour in the control group, but none in experimental groups(p = 0.02). The total urine sediment and protein contents were higher in the control group compared with experimental groups (p < 0.05).

DISCUSSION

Both study groups developed a uniform urothelial lining. Histologically, the group with smooth muscle had an added layer of submucosal smooth muscle. Six months after bladder augmentation the new lining was durable. We were also able to demonstrate that the reconstituted augmented segments secrete and absorb significantly less than the control colocystoplasty group. We used a non-validated simple method to evaluate permeability of the new urothelial lining to water. To determine if the aerosol transfer of bladder cells would have behaved differently in the neurogenic bladder population, this experiment should have been performed in animals with neuropathic bladders.

CONCLUSION

Aerosol spraying of single cell suspension of urothelial and muscular cells with fibrin glue resulted in coverage of the demucosalized intestinal segment with a uniform urothelial layer. This new lining segment was durable without regrowth of colonic mucosa after 6 months. The new reconstituted segment absorbs and secretes significantly less than control colocystoplasty.

Imaging submandibular pathology in the paediatric patient

A wide range of pathologies may arise from the submandibular space (SMS) or submandibular gland (SMG) in children. We review herein the normal anatomy of the SMS and describe the role of imaging in the evaluation of SMS lesions. A schematic approach for the categorisation of SMS pathology based on imaging characteristics is provided.

Application of continuous incisional infusion of local anesthetic after major pediatric urological surgery: prospective randomized controlled trial

PURPOSE

The aim of the study was to determine efficacy of continuous incisional infusion of local anesthetic, ON-Q® pain relief system (Kimberly-Clark, Georgia), in improving postoperative pain, reducing narcotic requirement, and shortening recovery time after major pediatric urological surgery.

MATERIAL AND METHODS

Prospective open-labeled randomized controlled trial comparing the ON-Q® pain relief system to standard of care pain management. Pain was assessed by nurses using the Visual Analog Scale or the Face, Legs, Activity, Cry, Consolability Scale depending on the child's age. Information regarding analgesic consumption and recovery parameters such as temperature, start of oral nutrition, and length of hospitalization were prospectively collected.

RESULTS

Patient's demographic, clinical, and surgical characteristics were similar in both groups. The ON-Q® group experienced significantly lower scores of maximal daily pain episodes compared to the control on the day of surgery (1.9±1.8 vs. 4.2±2.2 p=0.009) and first postoperative day (2.28±3.2 vs. 5.47±2.45 p=0.004). Mean number of narcotic doses was significantly lower in treatment group compared to control [Total (2.21 vs. 4.6 p=0.02), POD0 (0.7 vs. 1.7 p=0.02) and POD1 (1.3 vs. 2.8 p=0.04)].

CONCLUSION

The ON-Q® system is a viable option for postoperative pain management in children undergoing urological surgeries. This technology significantly decreases the amount of maximal pain, and the need for systemic narcotic consumption.

Development, reliability and validation of a neurogenic bowel dysfunction score in pediatric patients with spina bifida

OBJECTIVE

To develop a reliable and valid questionnaire to monitor neurogenic bowel symptoms in children.

PATIENTS

Thirty-four children aged 6-18 with neurogenic bowel and their caregivers. Eighteen control patients.

METHODS

An expert panel generated a domain of observables and formative/reflective content. Response options were scaled following Likert-type items. Key informant interviews revised the measures. A final questionnaire was given to patients twice to calculate intra-rater reliability using Cohen's Kappa Coefficient (k) and paired t-test. Blinded interviews were conducted after physical examination and health assessment and questionnaires completed by a nurse to determine construct validity and inter-rater reliability using k and Spearman's rank-order correlation. Control patients completed the questionnaire once, their results were used to determine discriminate validity and a receiver operating characteristic (ROC) curve.

RESULTS

Intra-rater reliability showed 85% of the questionnaires having k >0.6. Paired t-test results of t(33) = 1.997, P = 0.054, d = 0.53, confirmed there was not a significant difference between the scores of the two completed questionnaires. Inter-rater reliability showed 97% of the questionnaires having k >0.6 between the nurse and the patient/caregiver responses. Scores had a strong positive correlation at rs (32) = 0.943, P < 0.0005. Mean score with neurogenic bowel was 15.18(STD ±  5.77) and control group 4.68(STD ± 2.98). ROC analysis showed an area under the curve of 0.9. A score of 8.5 correlated with presence of neurogenic bowel with sensitivity of 94% and specificity of 87%.

CONCLUSION

The questionnaire shows positive reliability and validity when used for pediatric neurogenic bowel patients. The questionnaire differentiates between normal and neurogenic patients. Larger studies are necessary to conduct further validation.

Echinoderms: their culture and bioactive compounds

Of the five extant classes of echinoderms, it is the sea urchins (Echinoidea) and the sea cucumbers (Holothuroidea) that are both commercially fished and heavily overexploited. In sea urchins, it is the gonad of both males and females, normally referred to as'roe', that is a sought-after food. In the sea cucumber, the principal product is the boiled and dried body-wall or 'bêche-de-mer' for which there is an increasing demand. Many sea urchin and sea cucumber fisheries still have no management system or restrictions in place, and for those that do, the prognosis for catches to continue even at a reduced level is poor. Cultivation of these species increasingly becomes a necessity, both for stock enhancement programs and as a means to meet market demand. Sea urchin culture has been practised on a large scale in Japan for many decades, and effective methods for the culture and reseeding of species in these waters have been long established. Juvenile urchins are produced in their millions in state-sponsored hatcheries, for release to managed areas of seafloor. Outside of Japan, sea urchin cultivation is still a fairly recent practice, less than 10 years old, and largely still at a research level, although a range of species are now being produced in a variety of different culture systems. It is essential that the culture systems are adapted to be species-specific and meet with local environmental constraints. Sea cucumber cultivation originated in Japan in the 1930s and is now well established there and in China. Methods for mass cultivation of the tropical Holothuria scabra are now well established and practised in India, Australia, Indonesia, the Maldives and the Solomon Islands, with the focus of the research effort for both temperate and tropical species being centred on the production of juveniles in hatcheries for the restoration and enhancement of wild stocks. Like many other marine organisms, echinoderms have been, and continue to be, examined as a source of biologically active compounds with biomedical applications. Sea cucumber has been valued in Chinese medicine for hundreds of years as a cure for a wide variety of ailments. Some more recently isolated compounds, mainly from sea cucumbers and starfish, and including those with antitumour, antiviral, anticoagulant and antimicrobial activity are summarised below. When wild stocks decline, the demand created in the market place raises to the price of the product and, consequently, culturing is more likely to become viable economically. As this review shows, there have been dramatic advances in the culture methods of sea urchins and sea cucumbers in the last 10-15 years, to the extent that one can conclude that currently the major obstacles to successful cultivation are indeed economic rather than biological. Hence the future of the echinoculture industry is closely linked to that of the fisheries, whose fate will ultimately determine the market forces that will shape this growing industry.

Biosynthesis of eicosapentaenoic acid in the sea urchin Psammechinus miliaris

The sea urchin Psammechinus miliaris (Gmelin) (Echinodermata: Echinoidea) was shown by using a deuterated tracer (D5-18:3n-3) and quantitation by negative chemical ionization gas chromatography-mass spectrometry to convert 18:3n-3 to 20:5n-3. The rate of conversion was very slow, corresponding to 0.09 microg/g tissue/mg 18:3n-3 eaten over 14 d. Deuterated arachidonic acid (D8-20:4n-6) was also included in the diet to give a measure of the relative amounts of diet eaten by the different animals. The recovery of this fatty acid in tissue lipids was 33.7% compared with only 0.95% recovery of D5-18:3n-3 and its anabolites, indicating that the majority of the D5-tracer was catabolized. Considerable elongation of D5-18:3n-3 into 20:3n-3 and a trace of 22:3n-3 was found, and these were accompanied by minor amounts of the intermediates 18:4n-3 and 20:4n-3. No deuterated 22:6n-3 was found.

Fatty acid compositions of gonadal material and diets of the sea urchin, Psammechinus miliaris: trophic and nutritional implications

The fatty acid compositions of gonadal material was examined for the sea urchin Psammechinus miliaris (Gmelin) held in aquaria and fed either salmon feed pellets or the macroalga, Laminaria saccharina for 18 months. Gonadal material was also examined from P. miliaris collected from four field sites, including commercial scallop lines encrusted with the mussel, Mytilus edulis, sea cages stocked with Atlantic salmon Salmo salar and two intertidal sea-loch sites, characterised by either a fine mud or a macroalgal substratum. The fatty acid compositions of known and potential dietary material was examined. The proportions of certain fatty acids in the gonads of P. miliaris were significantly affected by diet type and location. Docosahexaenoic acid (DHA) 22:6 n-3 was significantly higher in the gonads of the sea urchins fed salmon feed in aquaria and collected from the salmon cages and scallop lines than in the gonads of the sea urchins fed L. saccharina in aquaria and collected from the intertidal sea loch sites. The salmon feed and the mussel tissue also contained a high proportion of this fatty acid. Stearidonic acid 18:4 n-3 and arachidonic acid 20:4 n-6, however, were found in significantly higher proportions than DHA in the gonads of the sea urchins fed L. saccharina and collected from the two intertidal sea-loch sites. L. saccharina was also found to contain high proportions of stearidonic and arachidonic acid. The gonads of the sea urchins collected from the intertidal site, characterised by a mud substratum, and from the scallop lines were found to contain a lower 18:1 n-9/18:1 n-7 ratio and a higher proportion of branched and odd-chained fatty acids, signifying a high dietary bacterial input, than the sea urchins held in the aquaria and collected from the salmon cage. 20:2 and 22:2 non-methylene-interrupted dienoic fatty acids (NMIDs) were found in P. miliaris fed diets lacking these fatty acids suggesting de novo biosynthesis. These results, therefore, suggest that the proportions/ratios of certain fatty acids in the gonads of P. miliaris could be used to give an indication of the predominant diet type of this species in the wild.

Intraoral radiographic storage phosphor image mean pixel values and signal-to-noise ratio: effects of calibration

OBJECTIVE

The DIGORA intraoral radiographic storage phosphor system needs to be calibrated before images are made. Calibration involves inputting of the maximum exposure to be used. This investigation studied the effects of different maximum exposure calibration settings on the mean pixel value for selected regions of interest and the signal-to-noise ratio for images of a test phantom.

STUDY DESIGN

A dental phantom containing a step wedge made of different thicknesses of homogeneously radiopaque bone-equivalent material was imaged at 70 kVp with exposures ranging from 12.8 to 105.2 microC.kg-1. Images were displayed through use of imaging software, and a region of interest was set for each bone-step. The mean pixel values and their standard deviations were measured.

RESULTS

Except for very low exposures (< 10% of the calibrated maximum), there was a linear relationship between exposure and the pixel values within the regions of interest irrespective of the calibrated maximum exposure. Low exposures resulted in underexposed low-contrast images. Low calibrated maximum exposures (< 54.5 microC.kg-1) resulted in low-density images with poor signal-to-noise ratios.

CONCLUSIONS

Because of the very wide image latitude of the DIGORA system, loss of image quality was not observed as a result of adjustments in the calibration setting over the range of exposure commonly used in dental practice. The highest accepted exposure was limited by prior calibration; hence, if diligence is applied, patient exposure can be minimized without detriment to image quality.

Charge-coupled device panoramic radiography: effect of beam energy on radiation exposure

OBJECTIVE

To determine the consequences for entrance exposure of varying the beam energy and operating current for panoramic radiography using a charge-coupled device receptor.

MATERIAL AND METHODS

Images were made of a RANDO average man phantom (Alderson Research Laboratories, Stamford, CT) at kVcp settings of 60, 66, 70 and 80 and an mA of 2.0, 3.2, 6.4 and 10.0. The exposure cycle was set as recommended by the manufacturer at 17.6 s. Diagnostic image quality was rated by a panel of two oral and maxillofacial radiologists and one oral and maxillofacial pathologist. Entrance exposures were assessed using a 3 cc ionization chamber placed at the beam entry points while imaging the molar, premolar, and anterior teeth both using the DigiPan (Trophy Radiologie, Vincennes, France) CCD receptor and conventional T-Mat G film/Lanex Regular screens (Eastman Kodak, Rochester, NY, USA).

RESULTS

Acceptable image quality was attained with combinations of 60 kVcp and 3.2, 6.4 or 10 mA, 70 kVcp and 2.0, 3.2 or 6.4 mA; at 80 kVcp irrespective of the mA it was unacceptable. The maximum reduction in entrance dose was 77%, averaged over the three sites, at 70 kVcp and 2 mA.

CONCLUSION

The DigiPan receptor produces satisfactory images with saving in entry exposure saving of approximately 70% when compared with a conventional film/rare earth screen combination.

Tissue radiation dosages using the RVG-S with and without niobium filtration

Tissue doses for a modified Rando head- and-neck phantom were measured for imaging with speed group E film with standardized aluminium filtration and the RVG-S both with and without added niobium filtration. Cylindrical holes drilled into the phantom's tissue-equivalent material permitted the placement of a small ionization chamber into anatomically correct sites representing the thyroid, parotid, submandibular and sublingual glands. To establish the necessary cone positions, angulations and time settings for each exposure, diagnostically acceptable images of six teeth, representative of different intraoral regions, were made for a DXXTR mannequin. Entrance and exit points were marked and transferred to the phantom to allow reproducible repeat exposures. The RVG-S provided reductions in average skin entrance dose of 31 per cent to 39 per cent with standard aluminium filtration and 51 per cent to 60 per cent with the addition of niobium filtration to attenuate the beam. While dose reductions relative to E-speed film usage were found for deep tissue sites, these were site and projection specific. The cumulative reduction from use of the RVG-S without niobium filtration was 32 per cent. It was 42 per cent with additional niobium filtration. It should be noted, however, that adding niobium filtration resulted in increased dosages to the deeper soft tissues such as the thyroid gland.

Adults with severe reading and learning difficulties: a challenge for the family physician

BACKGROUND

An estimated 40 to 44 million adults living in the United States have severe difficulty reading, writing, spelling, and doing arithmetic. These deficiencies interfere with their receiving adequate health care. Many of these adults have reading or other learning disabilities that further compromise their ability to understand their medical conditions and to participate fully in their own care.

METHODS

The literature on the cognitive and effective characteristics of adults with reading and learning disabilities was searched using the MEDLINE, PsychLIT, and ERIC databases. This literature is reviewed with an emphasis placed on how these characteristics might challenge a family physician's ability to provide optimal patient care, and what can be done to meet these challenges. Illustrative case vignettes of adults with these disabilities are described.

RESULTS AND CONCLUSIONS

The cognitive and affective characteristics of this patient population make it difficult for the family physician to provide optimal medical services. Suggestions are given to make medical care more accessible and appropriate for these patients.

The OP 100 Digipan: evaluation of the image layer, magnification factors, and dosimetry

OBJECTIVES

The purpose of this study was to describe the Orthopantomograph OP 100 Digipan modification and to determine the image-layer and dosimetric characteristics of this system.

RESEARCH DESIGN

Image-layer contours for the Digipan were determined at resolution limits of 4.0, 3.0, and 1.5 line pairs (Ip) mm(-1) using a resolution grid positioned at intervals along the beam projection paths. A hexagonal test device was placed above the grid to determine the magnification factors at the selected resolution limits. For dosimetry, a 30 mm2 ionization chamber was placed at the beam entry points while imaging the molar, premolar, and anterior teeth using both the Digipan and conventional film receptors.

RESULTS

The maximum resolution exceeded 4.0 Ip mm(-1)in the center of the image layer. Using a 1.5 Ip mm(-1) resolution limit, the focal trough width was 14 mm at 0-degree horizontal angulation, 20 mm at 37 degrees, and 36 mm at 83 degrees. At 1.5 Ip mm(-1), the horizontal magnification was -21% facial and +42% lingual to the center of the image layer in the incisor region; -25% facial and +19% lingual to the center of the image layer at a horizontal angulation of 83 degrees. At 4.0 Ip mm(-1), horizontal magnifications in the incisor region were -2.0% facially and +0.5% lingually; at 83 degrees they were -3.9% facially and +1.1% lingually. The neck entrance dose for imaging the anterior and premolar regions averaged 89.5 (+/-5.6) microGy. The cheek entrance doses for imaging the molar region averaged 220.6 (+/-8.0)microGy with the Digipan. With film the average entrance doses were 297.9 (+/-8.6) microGy (anterior and premolar regions) and 682.1 (+/-16.9) microGy (molar region).

CONCLUSIONS

The Digipan image layer is similar, but slightly narrower than that previously reported for the Orthopantomograph OP 100 using standard film-screen combinations. The resolution at the center of the image layer exceeded 4.0 Ip mm(-1). The Digipan produced images with an entry dose savings of approximately 70% when compared with photo-timed exposures using conventional film with the Orthopantomograph OP 100.

Inner-city adults with severe reading difficulties: a closer look

Relatively little is known about the characteristics of inner-city adults who seek assistance from literacy programs. Increased knowledge about this population will enhance the development of more effective programs, as well as policy options. This study describes the characteristics of 280 adults, ages 16 to 63, who came to an adult literacy program that focused on severe reading difficulties. The program, located within a hospital complex in a large, urban area, attracted these individuals through an extensive multimedia outreach effort. Results suggested that the adults who sought help were generally characterized by a vast array of cognitive, academic, and social difficulties. In addition, the extent of these difficulties increased dramatically as literacy level declined. These findings suggest that comprehensive educational, social, and vocational services may be needed to help adults with severe reading difficulties cope with the diverse and severe problems they face.

Perceptibility of defects in an aluminum test object: a comparison of the RVG-S and first generation VIXA systems with and without added niobium filtration

OBJECTIVE

To compare the first generation VIXA (Gendex, Milan, Italy) and the RVG-S (Trophy Radiologie, Vincennes, France) for detection of defects in an aluminium test object at various exposures both with and without added niobium filtration.

METHODS

Images of a 7 mm aluminium test object with defects ranging from 0.1 to 1.5 mm with standardized projection geometry. Seven dentists acted as observers. Perceptibility curves were developed for both sensors under the various filtration conditions and exposures.

RESULTS

At optimum exposures both the VIXA and the RVG-S permitted the same number of defects to be observed. The optimum exposures were similar for the two systems, but the dynamic range was greater for the RVG-S. Addition of niobium filtration did not appreciably alter the radiation dose required to perceive a given number of defects using either system.

CONCLUSIONS

The two systems performed equally at optimum exposure when the dose is approximately the same irrespective of the presence or absence of niobium filtration. Beyond the optimal level, the RVG-S outperformed the VIXA system.

The Incidence and Morphology of Subcuticular Bacteria in the Echinoderm Fauna of New Zealand

New Zealand echinoderms (33 species drawn from all five extant classes) were examined for the presence of symbiotic bacteria by fluorescence and electron microscopy. Gram-negative, subcuticular bacteria (SCB) were found in 17 species from four classes. The SCB could be classified into two major morphological types. Some species had both types of SCB. The distribution of SCB was not obviously linked to host ecology but did appear to be related to host phylogeny. Related species usually all have SCB or all lack them. The number of SCB in five species was estimated to be between 8.41 x 108 and 4.96 x 109 g-1 ash-free dry weight of host tissue. Significant differences in bacterial load and relative proportions of the different types of bacteria were found among three congeneric echinoids (Pseudechinus huttoni, P. albocinctus and P. novaezealandia). Ophiocoma bollonsi was peculiar in having groups of bacteria enclosed in host cells (bacteriocytes) within the connective tissue of the tube feet.

Comparing the sensitometric properties of dental X-ray films

This article describes a study that compared the sensitometric properties and information yields of four dental X-ray films: Eastman Kodak Ultra-Speed DF-57 and Ektaspeed EP-21, Flow DV-58 and Agfa Gevaert Dentus M2 Comfort. Dentus M2 Comfort gave the greatest contrast, a speed between the conventional D- and E-speed film groups and an exposure latitude wider than Ultra-Speed but less than DV-58. A significant difference in detail was found with low exposures, Dentus M2 Comfort and Ektaspeed outperforming the other two film types.

Direct digital radiography for the detection of defects in a standard aluminium test object through composite resin restorative materials

While the RVG 32000 (Trophy Radiologie, Vincennes, France) is in wide use for direct digital intraoral radiography in dentistry, there is a dearth of information in the literature concerning the system's sensitivity to small changes in radiographic density consistent with initial and recurrent dental caries. A standardized 7 mm aluminium test block was used as a phantom for perceptibility testing of density changes, both with and without the superimposition of composite resin sheets of various thicknesses. Defects in the block were randomly positioned and varied from 0.1 to 1.5 mm. Thermal prints were used for evaluation. Standard linear images, with no enhancement, were compared with three enhanced modes, standard mode with gradient enhancement (enhanced standard), standard X-function and zoom high resolution (ZHR). Sensitivity improved in the following sequence: standard 0.58 < enhanced standard 0.75 < X-function 0.94 < ZHR 0.95. Accuracy improved in the following sequence: standard 0.45 < enhanced standard 0.58 < X-function 0.73 < ZHR 0.74. Specificity was 1.0 both for X-function and for ZHR. These two modes both proved significantly better (P < 0.05) for the detection of 0.1 mm defects than the other two modes tested. No significant difference was found between X-function and ZHR. As ZHR requires four times the radiation exposure as standard exposures with the X-function, the latter is preferred for the task described in this study.

Flash Dent: an alternative charge-coupled device/scintillator-based direct digital intraoral radiographic system

The Flash Dent digital intraoral radiographic system is yet to be described in the scientific literature. A Windows operating environment, a lens based optical scintillator charge-coupled device (CCD) and 'IMG' image format are the major features which distinguish this from other available systems. In this paper we describe the component of the Flash Dent system, investigate the validity of the X-ray generator specifications, determine comparative image doses and assess the performance of the intraoral sensor. Although we found Flash Dent software facilitates image processing, X-ray generator operation, sensor performance and dimensional measurements, inconsistencies between sensors and the use of a non-standard image format require further consideration for improvements on the part of the manufacturer.

Diagnostic image quality and dose reduction using niobium filtration for cephalometric radiography

The usefulness of added filtration is contingent upon the maintenance of high image quality while effectively reducing the radiation dose. High-quality cephalometric radiographs, defined objectively by a panel of orthodontists, were obtained of a tissue-equivalent phantom both without and with 30 microns and 50 microns supplemental niobium filtration. Skin entrance doses in the temporomandibular joint region were compared at diagnostically acceptable exposures where there was no significant difference in radiographic image quality. Dose reductions ranged from 17% to 31% with 30 microns niobium filtration, and 17% to 39% with 50 microns. However, as kVp and HVL were increased to maintain the same level of perceived image quality, image contrast decreased. Contrast loss with 30 microns and 50 microns niobium filtration averaged 8% and 22% respectively compared with standard aluminium filtration. It would appear that additional niobium filtration can be used to reduce radiation dose without significant loss of image quality.

The effect of cocaine on sperm motility characteristics and bovine cervical mucus penetration

OBJECTIVES

To determine the in vitro effects of cocaine on sperm motility and bovine mucus penetration because cocaine abuse is associated with decreased sperm motility, and related compounds, such as procaine, are known to decrease sperm motility.

DESIGN

Human semen samples were exposed to a range of cocaine concentrations and the effects quantified using computer-assisted sperm analysis and the bovine mucus penetration test.

SETTING

University research laboratory.

PATIENTS, PARTICIPANTS

Samples were obtained from 18 healthy volunteers.

INTERVENTIONS

Normal semen samples were exposed to concentrations of cocaine ranging from 10(-11) to 10(-4) M. Motility characteristics were evaluated after 2 hours, and bovine mucus penetration was evaluated after 30 minutes, 1 hour, and 2 hours. Mucus penetration by washed sperm was also evaluated.

MAIN OUTCOME MEASURES

Motility characteristics were evaluated using computer-assisted sperm analysis, and functional sperm motility was evaluated using the bovine mucus penetration test.

RESULTS

Cocaine exposure decreased the percentage of motile sperm in a concentration-dependent manner with a maximum decrease of 23% at 10(-4) M but had no effect on other motility characteristics. Cocaine decreased bovine mucus penetration by 12% at high cocaine concentrations (10(-4) M), but increased penetration by 69% at low concentrations (10(-9) M). Washing sperm before cocaine exposure attenuated the increased sperm penetration.

CONCLUSION

The ability of cocaine to decrease the percentage of motile sperm at high concentrations may explain the decreased sperm motility associated with cocaine use. Cocaine's ability to augment sperm penetration at low concentrations suggests an interaction of cocaine with the sperm adrenergic system.

Cognitive processing deficits in reading disabilities: a prefrontal cortical hypothesis

Much research investigating the neuropsychological underpinnings of reading disabilities has emphasized posterior brain regions. However, recent evidence indicates that prefrontal cortex may also play a role. This study investigated cognitive processes that are associated with prefrontal and posterior brain functions. Subjects were 12-year-old reading disabled and nondisabled boys. Discriminant analysis procedures indicated that measures of prefrontal functions distinguished between the two groups better than measures of posterior functions. The results suggest that reading disabled boys have difficulty with cognitive processes involving selective and sustained attention, inhibition of routinized responses, set maintenance, flexibility in generating and testing alternative hypotheses, and phonemically based language production.

Evaluation of aluminum-yttrium filtration for intraoral radiography

In comparison with the use of traditional aluminum filtration, a radiation dose reduction of 40% at 90 kVp and 25% at 70 kVp was found with the use of aluminum-yttrium (Al-Y) filtration for intraoral bitewing and periapical radiographs. An increased exposure time, and consequent greater tube loading, was necessary to maintain film density. Extended gray-scales (i.e., reduced radiographic contrast) occurred at both energy levels tested with the use of Al-Y filtration. Subjective evaluation of image quality in terms of clarity, resolution, and contrast was carried out independently by nine periodontologists. Despite some interoperator variance, there was a preponderant preference for traditional aluminum filtration.