Model matters: Differential outcomes in traumatic optic neuropathy pathophysiology between blunt and blast-wave mediated head injuries

Over 3 million people in the United States live with long-term disability because of a traumatic brain injury (TBI). The purpose of this study was to characterize and compare two different animal models of TBI (blunt head trauma and blast TBI) to determine common and divergent characteristics of these models. With recent literature reviews noting the prevalence of visual system injury in animal models of TBI, coupled with clinical estimates of 50-75% of all TBI cases, we decided to assess commonalities, if they existed, through visual system injury. A unilateral (left directed) blast and repeat blast model injury with coup-contra-coup injury patterns were compared to a midline blunt injury. Injuries were induced in adult male mice to observe and quantify visual deficits. Retinal ganglion cell loss and axonal degeneration in the optic tract, superior colliculus, and lateral geniculate nuclei were examined to trace injury outcomes throughout major vision-associated areas. Optokinetic response, immunohistochemistry, and western blots were analyzed. Where a single blunt injury produces significant visual deficits a single blast injury appears to have less severe visual consequences. Visual deficits after repeat blasts are similar to a single blast. Single blast injury induces contralateral damage to the right optic chiasm and tract whereas bilateral injury follows a single blunt TBI. Repeat blast injuries are required to see degeneration patterns in downstream regions similar to the damage seen in a single blunt injury. This finding is further supported by amyloid precursor protein (APP) staining in injured cohorts. Blunt injured groups present with staining 1.2 mm ahead of the optic nerve, indicating axonal breakage closer to the optic chiasm. In blast groups, APP was identifiable in a bilateral pattern only in the geniculate nucleus. Evidence for unilateral neuronal degeneration in brain tissue with bilateral axonal ruptures are pivotal discoveries in this model differentiation. Analysis of the two injury models suggests that there is a significant difference in the histological outcomes dependent on injury type, though visual system injury is likely present in more cases than are currently diagnosed clinically.

Women in Irish urology: An examination of female representation amongst attendees of the Irish Society of Urology annual meeting (2008-2020)

BACKGROUND

There is underrepresentation of women at surgical conferences. We examine the representation of women in Irish urology by looking at gender balance within the Irish Society of Urology (ISU) conference.

AIMS

ISU programmes over thirteen years from 2008 to 2020 were assessed and female representation in session chairs, guest speakers, poster and oral presentations identified. Gender distributions of authors for each year was examined. To investigate changes in female representation temporally, the period of this study (2008-2020) was subdivided and compared: 2008-2013 and 2014-2020.

RESULTS

76 sessions were presided over by 138 chairs, of which 6 (4.3%) were female. Eight conferences had zero female chairs. 62 guest lectures were given, 6 (9.6%) by women. Of total 340 poster and 434 oral presentations, women delivered 24.9% (0-47.5%) of posters and 31.6% (10.3-59.4%) of oral presentations. We found no significant difference in the percentage of female poster presentations between the time periods 2008-2013 (m = 18.2, sd = 13.7) and 2014-2020 (m = 34.3, sd = 17.8), t(11) = -1.4, p > 0.05. However, we found a significant difference in the percentage of female oral presentations between the periods 2008-2013 (m = 18.7, sd = 14.2) and 2014-2020 (m = 40.6, sd = 14.5), t(11) = -2.8, p < 0.05.

CONCLUSIONS

Our study is the second to examine female representation in Irish urology. Session chairs and guest speakers were grossly overrepresented by males as were oral and poster presentations. Despite lacking female influence overall, in more recent years there was an increased representation of women. Societies should strive to increase female representation, as this perpetuates a positive feedback loop, encouraging future female trainees to pursue urological surgery.

Patient-Centric Product Development: A Summary of Select Regulatory CMC and Device Considerations

Patient-centric drug development describes the systematic approach to incorporating the patient's perspectives and preferences into the design, assessment, and production of a therapeutic product. While a patient centric approach can be applied at any stage of the drug development lifecycle, an integrated end-to-end strategy is often most effective to create an optimized product for the patient at the earliest possible timepoint. The importance of patient centricity is well recognized by health authorities and biopharmaceutical organizations which have established toolsets, guidances, and methodologies for incorporating patient input during the clinical stage of development. However, in addition to clinical research, there are other significant aspects of product development that profoundly impact the patient experience. Specifically, chemistry, manufacturing, and control (CMC) and device aspects must also be acknowledged and addressed as part of a cohesive patient-centric development strategy. This review explores current applications and regulatory considerations for patient-centric approaches across the product lifecycle, including R&D, early product development, clinical development, device and combination product development, and post-approval change management. Specific topics of discussion include the contributions of product modality, formulation, and devices to the patient experience; usage of the Quality Target Product Profile (QTPP) as a patient-centered design tool; and post-approval product optimization. Future advancements in regulatory data management and information exchange are also explored as potential enablers of patient engagement which support enhanced communication and interconnectivity between stakeholders. Multidisciplinary collaboration between patients, health authorities, health care providers, and the biopharmaceutical industry is ultimately necessary for ensuring that medicinal products, and their corresponding regulatory processes, take on a patient-first mindset that prioritizes patient needs, values, and preferences.

401 Three Birds with One Stone: Ureteric Calculus Precipitates Diagnosis and Resection of Three Primary Neoplasms

A 67 year-old female presented to our centre with a 2 day history of right flank pain, clinically suggestive of ureteric colic. Computed tomography (CT) confirmed a 6mm right ureteric calculus. However, CT also revealed a large 13cm ipsilateral renal mass, concerning for renal cell carcinoma (RCC). At ureteroscopy for management of the obstructing calculus, a small papillary lesion was noted in the bladder, and excised. Histology confirmed pTa low-grade transitional cell carcinoma.

Following discussion at the Urology multidisciplinary tumour board, MRI venogram (MRV) was recommended to delineate the extension of tumour into the renal vein, and to characterise a pelvic mass seen on original CT. MRV showed enhancing material extending into the IVC, consistent with tumour thrombus. However, it also identified a concerning 6cm solid ovarian mass.

The patient proceeded to open right radical nephrectomy and IVC thrombectomy, hysterectomy, bilateral salpingo-oopherectomy, and omental biopsy, with combined input from Urological, Gynaecological and Vascular surgical teams. Post-operative course was uneventful. Histology showed an 11cm pT3a G2 clear cell RCC, and 7.5cm ovarian fibroma, both fully excised. This case demonstrated the serendipity of a simple ureteric calculus precipitating a cascade of investigations, that ultimately led to complete resection of three primary neoplasms.

Does instillation of lidocaine gel following flexible cystoscopy decrease the severity of post procedure symptoms? A randomised controlled trial assessing the efficacy of lidocaine gel post flexible cystoscopy

Objective

To assess whether instillation of lidocaine gel both before and after flexible cystoscopy is more effective at reducing post procedural symptoms than instillation of lidocaine gel pre flexible cystoscopy alone. We hypothesise that inadequate urethral dwell time and dilution of lidocaine gel by the irrigation fluid during flexible cystoscopy limits its anaesthetic efficacy. Only one other study has attempted to reduce bothersome urinary symptoms through an intervention after flexible cystoscopy.

Methods

This was a randomised controlled trial in which patients were randomised 1:1 to receive lidocaine gel pre and post flexible cystoscopy (treatment) or lidocaine gel pre flexible cystoscopy only (control). Patient-reported outcome measures were used to assess symptoms and quality of life prior to cystoscopy, on day 2 and day 7 post cystoscopy.

Result

Fifty patients were divided equally between the treatment and control groups. There were no significant differences in baseline characteristics between the groups (p = 1.000). An overall symptoms variable was measured, though no significant difference was found in the distribution of responses between the groups at baseline, 2 or 7 days after the flexible cystoscopy (p = 0.423, 0.651,0.735). In the treatment group, 1 patient (4.0%) presented to a doctor for review following flexible cystoscopy, and 4 patients (16.0%) presented in the control group (p = 0.349).

Conclusion

Initial study results suggest that post-operative lidocaine does not significantly limit the exacerbation of urinary symptoms following flexible cystoscopy; however, our results are not powered to detect a small difference. We do not recommend a change in practice based on our results.

The Canadian Neuromuscular Disease Registry 2010-2019: A Decade of Facilitating Clinical Research Througha Nationwide, Pan-NeuromuscularDisease Registry

We report the recruitment activities and outcomes of a multi-disease neuromuscular patient registry in Canada. The Canadian Neuromuscular Disease Registry (CNDR) registers individuals across Canada with a confirmed diagnosis of a neuromuscular disease. Diagnosis and contact information are collected across all diseases and detailed prospective data is collected for 5 specific diseases: Amyotrophic Lateral Sclerosis (ALS), Duchenne Muscular Dystrophy (DMD), Myotonic Dystrophy (DM), Limb Girdle Muscular Dystrophy (LGMD), and Spinal Muscular Atrophy (SMA). Since 2010, the CNDR has registered 4306 patients (1154 pediatric and 3148 adult) with 91 different neuromuscular diagnoses and has facilitated 125 projects (73 academic, 3 not-for-profit, 3 government, and 46 commercial) using registry data. In conclusion, the CNDR is an effective and productive pan-neuromuscular registry that has successfully facilitated a substantial number of studies over the past 10 years.

Critical care usage after major gastrointestinal and liver surgery: a prospective, multicentre observational study

BACKGROUND

Patient selection for critical care admission must balance patient safety with optimal resource allocation. This study aimed to determine the relationship between critical care admission, and postoperative mortality after abdominal surgery.

METHODS

This prespecified secondary analysis of a multicentre, prospective, observational study included consecutive patients enrolled in the DISCOVER study from UK and Republic of Ireland undergoing major gastrointestinal and liver surgery between October and December 2014. The primary outcome was 30-day mortality. Multivariate logistic regression was used to explore associations between critical care admission (planned and unplanned) and mortality, and inter-centre variation in critical care admission after emergency laparotomy.

RESULTS

Of 4529 patients included, 37.8% (n=1713) underwent planned critical care admissions from theatre. Some 3.1% (n=86/2816) admitted to ward-level care subsequently underwent unplanned critical care admission. Overall 30-day mortality was 2.9% (n=133/4519), and the risk-adjusted association between 30-day mortality and critical care admission was higher in unplanned [odds ratio (OR): 8.65, 95% confidence interval (CI): 3.51-19.97) than planned admissions (OR: 2.32, 95% CI: 1.43-3.85). Some 26.7% of patients (n=1210/4529) underwent emergency laparotomies. After adjustment, 49.3% (95% CI: 46.8-51.9%, P<0.001) were predicted to have planned critical care admissions, with 7% (n=10/145) of centres outside the 95% CI.

CONCLUSIONS

After risk adjustment, no 30-day survival benefit was identified for either planned or unplanned postoperative admissions to critical care within this cohort. This likely represents appropriate admission of the highest-risk patients. Planned admissions in selected, intermediate-risk patients may present a strategy to mitigate the risk of unplanned admission. Substantial inter-centre variation exists in planned critical care admissions after emergency laparotomies.

The CanPain SCI Clinical Practice Guidelines for Rehabilitation Management of Neuropathic Pain after Spinal Cord: introduction, methodology and recommendation overview

STUDY DESIGN

Clinical practice guidelines.

OBJECTIVES

The objective was to develop the first Canadian clinical practice guidelines for the management of neuropathic pain in people with spinal cord injury (SCI).

SETTING

The guidelines are relevant for inpatient and outpatient SCI rehabilitation settings in Canada.

METHODS

The guidelines were developed in accordance with the Appraisal of Guidelines for Research and Evaluation II tool. A Steering Committee and Working Group reviewed the relevant evidence on neuropathic pain management (encompassing screening and diagnosis, treatment and models of care) after SCI. The quality of evidence was scored using Grading of Recommendations Assessment, Development and Evaluation (GRADE). A consensus process was followed to achieve agreement on recommendations and clinical considerations.

RESULTS

The Working Group developed 12 recommendations for screening and diagnosis, 12 recommendations for treatment and 5 recommendations for models of care. Important clinical considerations accompany each recommendation.

CONCLUSIONS

The Working Group recommendations for the management of neuropathic pain after SCI should be used to inform practice.

OC-14 - Baseline D-dimer levels are predictive of recurrent venous thromboembolism (VTE) at 6 months in cancer patients with VTE treated with tinzaparin

INTRODUCTION

VTE is a major complication in cancer patients. Despite treatment with low molecular weight heparin (LMWH), 9% will have recurrent VTE within 6 months. Measurement of plasma biomarkers in cancer patients receiving LMWH may be predictive of recurrent VTE or overall survival (OS).

AIM

We conducted a single arm phase 2 study to evaluate the efficacy and safety of once daily tinzaparin for the initial treatment and extended prophylaxis of VTE in cancer patients. The study included a prospective analysis of plasma biomarkers D-dimer and IL-6 to assess whether these were predictive of recurrent VTE or OS.

MATERIALS AND METHODS

Consecutive patients with active cancer diagnosed with a pulmonary embolism (PE) and/or proximal deep venous thrombosis (DVT) at the University of Southern California Norris Comprehensive Cancer Center, Los Angeles County Medical Center, or New York Presbyterian - Weill Cornell Medical Center were invited to participate in this study with a target enrollment of 100 patients. Key eligibility criteria included: age ≥18, ECOG score ≤2, adequate organ function, and ≥6 month estimated survival. Patients were treated with daily subcutaneously tinzaparin 175 U/kg for 6 months on study. Tinzaparin could be continued ≤1 year at the discretion of the treating physician. All patients who received ≥1 dose were evaluable for efficacy and safety. Primary study endpoints were recurrent VTE or major bleeding. Secondary outcome measures included OS and plasma biomarkers. Biomarkers were measured at baseline, 7 days, 1 month and 6 months after tinzaparin initiation. Patients who had baseline and 1 week or 1 month samples collected were included in the biomarker analysis.

RESULTS

97 patients were enrolled. 2 patients were ineligible. 8 patients did not have baseline or follow-up biomarkers completed. 87 patients were included in the analysis. 28 (32%) of patients completed≥6 months of tinzaparin. Major bleeding occurred in 2 patients. 11 patients had recurrent VTE at 6 months (3 PE, 7 DVT, 1 central venous thrombosis not associated with a catheter). Median baseline D-dimer level was 2759 ng/mL (range: 375-37,591). Median baseline IL-6 level was 9.4 pg/mL (range: 0.8-20.9). Baseline D-dimer>median was predictive of VTE recurrence at 6 months (p=.006). Baseline IL-6>median was not predictive of VTE recurrence at 6 months. Neither 1 month D-dimer or IL-6 levels were predictive of VTE recurrence at 6 months. D-dimer and IL-6 at baseline and at 1 month were not predictive of OS.

CONCLUSIONS

In patients with active cancer and VTE treated with tinzaparin, baseline D-dimer levels above the median value were predictive of VTE recurrence at 6 months.

Risk of recurrent venous thromboembolism and major hemorrhage in cancer-associated incidental pulmonary embolism among treated and untreated patients: a pooled analysis of 926 patients

ESSENTIALS: We performed a pooled analysis of 926 patients with cancer-associated incidental pulmonary embolism (IPE). Vitamin K antagonists (VKA) are associated with a higher risk of major hemorrhage. Recurrence risk is comparable after subsegmental and more proximally localized IPE. Our results support low molecular weight heparins over VKA and similar management of subsegmental IPE.

BACKGROUND

Incidental pulmonary embolism (IPE) is defined as pulmonary embolism (PE) diagnosed on computed tomography scanning not performed for suspected PE. IPE has been estimated to occur in 3.1% of all cancer patients and is a growing challenge for clinicians and patients. Nevertheless, knowledge about the treatment and prognosis of cancer-associated IPE is scarce. We aimed to provide the best available evidence on IPE management.

METHODS

Incidence rates of symptomatic recurrent venous thromboembolism (VTE), major hemorrhage, and mortality during 6-month follow-up were pooled using individual patient data from studies identified by a systematic literature search. Subgroup analyses based on cancer stage, thrombus localization, and management were performed.

RESULTS

In 926 cancer patients with IPE from 11 cohorts, weighted pooled 6-month risks of recurrent VTE, major hemorrhage and mortality were 5.8% (95% confidence interval [CI] 3.7-8.3%), 4.7% (95% CI 3.0-6.8%), and 37% (95% CI 28-47%). VTE recurrence risk was comparable under low molecular weight heparins (LMWH) and vitamin K antagonists (VKAs) (6.2% vs. 6.4%; hazard ratio [HR] 0.9; 95% CI 0.3-3.1), while 12% in untreated patients (HR 2.6; 95% CI 0.91-7.3). Risk of major hemorrhage was higher under VKAs than under LMWH (13% vs. 3.9%; HR 3.9; 95% CI 1.6-10). VTE recurrence risk was comparable in patients with an subsegmental IPE and those with a more proximally localized IPE (HR 1.1; 95% CI 0.50-2.4).

CONCLUSION

These results support the current recommendation to anticoagulate cancer-associated IPE with LMWH and argue against different management of subsegmental IPE.

Extinction retention and fear renewal in a lifetime obsessive-compulsive disorder sample

Obsessive-compulsive disorder (OCD), like other illnesses with prominent anxiety, may involve abnormal fear regulation and consolidation of safety memories. Impaired fear extinction memory (extinction recall, ER) has been shown in individuals with current symptoms of OCD [1]. However, contrary to expectations, the only previous study investigating this phenomenon showed a positive correlation between extinction recall abilities and OCD symptomology (i.e., as OCD symptoms worsened, extinction memory improved). The purpose of the current study was to determine if patients with a lifetime diagnosis of OCD (not necessarily currently symptomatic) also demonstrate impairments in extinction memory, and the relationship between OCD symptomology and extinction memory in this type of sample. In addition, we also examined fear renewal, which has never been investigated in an OCD sample. We enrolled 37 patients with OCD, the majority of whom were on serotonin reuptake inhibitors, and 18 healthy control participants in a 2-day paradigm assessing fear conditioning and extinction (Day 1) and extinction retention and renewal (Day 2). Skin conductance responses (SCRs) were the dependent measure. Results, as in the prior study, indicated that the only between-group difference was impaired ER in OCD patients relative to controls. Contrary to our prediction, OCD symptom severity was not correlated with the magnitude of extinction recall. There were no differences in fear renewal between OCD patients and controls.

Outcomes of pregnancies in women with suspected antiphospholipid syndrome

OBJECTIVES

To evaluate maternal and neonatal outcomes in women suspected to have primary antiphospholipid syndrome (PAPS).

METHODS

A cohort from the Nova Scotia Atlee Perinatal Database (n = 211034) was studied. A total of 58 women with antiphospholipid antibodies without a clinical diagnosis of rheumatologic disease were evaluated. We compared them to maternal and neonatal outcomes of women without rheumatologic disease or PAPS who delivered in Nova Scotia 1988-2008.

RESULTS

With PAPS, mean maternal age was older; mean gestational age and mean neonatal birth weight were less. With bivariate analysis, maternal colonization and urinary tract infection with group B streptococcus, thromboembolic disease, thrombocytopenia and Caesarean birth were more frequent in the suspected PAPS group compared to the control. Among neonates, hyperbilirubinemia, anemia, apnea, intraventricular hemorrhage grade I and II, retinopathy of prematurity, bronchopulmonary dysplasia, neonatal intensive care unit admission, and assisted ventilation occurred more frequently with PAPS. Babies in PAPS group had a longer hospital stay (8.7 vs 3.9 days). Logistic regression analysis identified that PAPS was only associated with increased risks of preeclampsia (Odds Ratio (OR) 2.2; 95% Confidence Interval (CI) 1.1-4.3; P = 0.016), urinary tract infection (OR 2.2; 95% CI 1.1-4.6; P = 0.02), and prematurity (gestational age ≤37) (OR 2.2; 95% CI, 1.07-4.3, P = 0.03). Positive predictive values for pregnancy induced hypertension, urinary tract infection and prematurity in women who had suspected APS were 24.1%, 17.2% and 45.6% respectively.

CONCLUSION

With suspected PAPS, risks for preeclampsia, urinary tract infection and prematurity are increased. Outcomes for babies are related to prematurity.

Unsuspected pulmonary emboli adversely impact survival in patients with cancer undergoing routine staging multi-row detector computed tomography scanning

BACKGROUND

While symptomatic venous thromboembolism adversely impacts survival among cancer patients, the outcome of cancer patients with unsuspected pulmonary embolism (UPE) found on routine cancer staging multi-row detector computed tomography (MDCT) scans is unknown.

OBJECTIVE

To determine whether UPE detected on routine staging MDCT scans impacts overall survival among cancer patients.

PATIENTS AND METHODS

We performed a matched cohort study of cancer patients diagnosed with UPE on routine staging scans between May 2003 and August 2006. Two controls (n = 137) were individually matched by age (± 5 years), cancer type and stage for each UPE patient (n = 70). We used Cox's proportional hazard models to compare the mortality between UPE patients and their matched controls.

RESULTS

The hazard ratio (HR) for death among UPE patients was 1.51 (95% CI 1.01-2.27, P = 0.048). Compared with their matched controls, patients with UPE more proximal than the subsegmental arterial branches had a HR for death at 6 months of 2.28 (95% CI 1.20-4.33, P = 0.011) and an overall HR of 1.70 (95% CI 1.06-2.74, P = 0.027). Survival among UPE patients with isolated subsegmental PE (ISSPE) was not significantly different than that of matched controls (HR 1.04 95% CI 0.44-2.39, P = 0.92).

CONCLUSIONS

UPE identified more proximal than the subsegmental arterial branches has a significant negative impact on survival among cancer patients.

Ionization-induced electron trapping in ultrarelativistic plasma wakes

The onset of trapping of electrons born inside a highly relativistic, 3D beam-driven plasma wake is investigated. Trapping occurs in the transition regions of a Li plasma confined by He gas. Li plasma electrons support the wake, and higher ionization potential He atoms are ionized as the beam is focused by Li ions and can be trapped. As the wake amplitude is increased, the onset of trapping is observed. Some electrons gain up to 7.6 GeV in a 30.5 cm plasma. The experimentally inferred trapping threshold is at a wake amplitude of 36 GV/m, in good agreement with an analytical model and PIC simulations.

Dilatation of the ascending aorta in paediatric patients with bicuspid aortic valve: frequency, rate of progression and risk factors

OBJECTIVES

To describe the incidence and rate of dilatation of the ascending aorta in children with bicuspid aortic valve (BAV) and to determine factors that predict rapid aortic dilatation.

DESIGN

Retrospective cohort study.

SETTING

Regional tertiary care children's hospital.

PATIENTS

All children aged 0-18 years seen at the authors' institution between 1990 and 2003 with an "isolated" BAV. All patients had had more than one technically adequate echocardiogram, at least six months apart, with concomitant height and weight data.

INTERVENTIONS

Offline echocardiographic measurements of multiple levels of the aortic root were completed for each participant at each serial echocardiogram. These measurements were then compared with expected measurements derived from a normal local control population.

MAIN OUTCOME MEASURES

Rate of change of the ascending aorta size over time, where aortic size is expressed as the number of standard deviations above or below the mean size expected for a given body surface area (z score).

RESULTS

279 echocardiograms spanning a period of from 9 months to 13.3 years were analysed for 88 patients with BAV. The ascending aorta in the BAV group was larger than expected for body surface area at diagnosis and continued to increase in relative size at each of the four subsequent follow-up echocardiograms. Ascending aortic z score increased at an average rate of 0.4/year. A faster rate of increase in z score was predicted by both larger initial aortic valve gradient and non-use of beta blockers.

CONCLUSIONS

Children with BAV are at risk of having a dilated ascending aorta. This risk increases with longer follow up.

Hose instability and wake generation by an intense electron beam in a self-ionized gas

The propagation of an intense relativistic electron beam through a gas that is self-ionized by the beam's space charge and wakefields is examined analytically and with 3D particle-in-cell simulations. Instability arises from the coupling between a beam and the offset plasma channel it creates when it is perturbed. The traditional electron hose instability in a preformed plasma is replaced with this slower growth instability depending on the radius of the ionization channel compared to the electron blowout radius. A new regime for hose stable plasma wakefield acceleration is suggested.

Molecular characterization of guinea - pig (Cavia porcellus) CD8alpha and CD8beta cDNA

CD8 is expressed on cytotoxic T cells (CTL) and functions as a coreceptor for recognition of major histocompatibility complex (MHC) class I peptide complexes by the T-cell receptor (TCR). The CD8 molecule consists of two subunits (alpha and beta) and exists either as a heterodimer (alphabeta) or a homodimer (alphaalpha). We report the cloning of full-length cDNAs of guinea pig CD8alpha and CD8beta. The deduced amino acid sequence of CD8alpha and CD8beta reveals characteristic structural features including a signal peptide, an immunoglobulin (Ig) variable-like region, hinge region, transmembrane, and cytoplasmic domains. In addition to the full-length cDNA, a splice variant of CD8beta cDNA was observed, suggesting splicing events as reported for human CD8beta. The sequence homology of guinea pig CD8 indicates greater homology to human, canine, and feline counterparts than to rodent CD8. As the guinea pig serves as an ideal non-primate animal model to several human infectious diseases, such as syphilis, tuberculosis, and chlamydial genital and ocular infection, the CD8 sequence information provides a necessary molecular tool for studying the cell-mediated immune response.

Plasma wakefield acceleration in self-ionized gas or plasmas

Tunnel ionizing neutral gas with the self-field of a charged particle beam is explored as a possible way of creating plasma sources for a plasma wakefield accelerator [Bruhwiler et al., Phys. Plasmas (to be published)]. The optimal gas density for maximizing the plasma wakefield without preionized plasma is studied using the PIC simulation code OSIRIS [R. Hemker et al., in Proceeding of the Fifth IEEE Particle Accelerator Conference (IEEE, 1999), pp. 3672-3674]. To obtain wakefields comparable to the optimal preionized case, the gas density needs to be seven times higher than the plasma density in a typical preionized case. A physical explanation is given.

C4bp binding to porin mediates stable serum resistance of Neisseria gonorrhoeae

Screening of 29 strains of Neisseria gonorrhoeae revealed that 16/21 serum resistant strains and 0/8 serum sensitive strains bound C4bp, suggesting that C4bp binding to gonococci could contribute to serum resistance. C4bp bound to gonococci retained cofactor (C4b-degrading) function. Using allelic exchange to construct strains with hybrid Por1A/B molecules, we demonstrate that the N-terminal loop (loop 1) of Por1A is required for C4bp binding. Serum resistant Por1B gonococcal strains also bind C4bp via their Por molecule. Using allelic exchange and site-directed mutagenesis, we have shown that loops 5 and 7 together form a negatively charged C4bp binding domain. C4bp-Por1B interactions are ionic in nature (inhibited by high salt as well as by heparin), while the C4bp-Por1A bond is hydrophobic. mAbs directed against SCR1 of the alpha-chain of C4bp inhibit C4bp binding to both Por1A and Por1B. Furthermore, only recombinant C4bp mutant molecules that contain alpha-chain SCR1 bind both Por1A and Por1B gonococci, confirming that SCR1 contains Por binding sites. C4bp alpha-chain monomers do not bind strains with either Por molecule, suggesting that the polymeric form of C4bp is required for binding to gonococci. Inhibition of C4bp binding to serum resistant Por1A and Por1B strains in a serum bactericidal assay using fAb fragments against C4bp SCR1 results in complete killing at 30 min of otherwise fully serum resistant strains in only 10% normal serum, underscoring the role of C4bp in mediating gonococcal serum resistance.

Binding of C4b-binding protein to porin: a molecular mechanism of serum resistance of Neisseria gonorrhoeae

We screened 29 strains of Neisseria gonorrhoeae and found 16/21 strains that resisted killing by normal human serum and 0/8 serum sensitive strains that bound the complement regulator, C4b-binding protein (C4bp). Microbial surface-bound C4bp demonstrated cofactor activity. We constructed gonococcal strains with hybrid porin (Por) molecules derived from each of the major serogroups (Por1A and Por1B) of N. gonorrhoeae, and showed that the loop 1 of Por1A is required for C4bp binding. Por1B loops 5 and 7 of serum-resistant gonococci together formed a negatively charged C4bp-binding domain. C4bp-Por1B interactions were ionic in nature (inhibited by high salt or by heparin), whereas the C4bp-Por1A bond was hydrophobic. Only recombinant C4bp mutant molecules containing the NH2-terminal alpha-chain short consensus repeat (SCR1) bound to both Por1A and Por1B gonococci, suggesting that SCR1 contained Por binding sites. C4bp alpha-chain monomers did not bind gonococci, indicating that the polymeric form of C4bp was required for binding. Using fAb fragments against C4bp SCR1, C4bp binding to Por1A and Por1B strains was inhibited in a complement-dependent serum bactericidal assay. This resulted in complete killing of these otherwise fully serum resistant strains in only 10% normal serum, underscoring the importance of C4bp in mediating gonococcal serum resistance.

Transient spine density increases in the mid-molecular layer of hippocampal dentate gyrus accompany consolidation of a spatial learning task in the rodent

In previous studies, we observed a transient increase in dendritic spine frequency in the molecular layer of the dentate gyrus at 6h following passive avoidance training [O'Malley A., O'Connell C. and Regan C. M. (1998) Neuroscience 87, 607-613]. To determine if a similar change is associated with spatial forms of learning, we have estimated time-dependent modulations of spine number in the dentate gyrus of the adult rat following water maze training. All animals exhibited significant reductions in the latency to locate the platform over the five training sessions of the single trial (median and interquartile ranges of 60, 8 versus 8, 3 s for trials 1 and 5, respectively) and this improved performance was retained just prior to killing at the 6h post-training time. The unbiased dissector stereological procedure was used to estimate spine number in serial pairs of ultrathin coronal sections obtained at a point 3.3 mm caudal of Bregma. This analysis revealed a significant learning-associated increase in spine number at the 6h post-training time (1.32+/-0.18 spines/microm(3)) as it was not observed in paired controls exposed to the water maze for a similar swim-time (0.66+/-0.11 spines/microm(3)). The increase was transient as spine number returned to control levels at the 72 h post-training time. These spine frequency changes are proposed to reflect increased synapse turnover rate and concomitant change in connectivity pattern in the processing of information for long-term storage.

A culture of change or a change of culture?

As organizations find themselves having to respond to quick changes in rapid succession, at some point the question of whether or not the pace is too much to sustain comes into play. At Sarasota Memorial Hospital, early cultural assessment led to implementation strategies that helped to overcome some of the barriers of major change.

A comparison of phonemic, semantic, and alternating word fluency in Parkinson's disease

Word fluency in 45 medicated non-demented Parkinson's disease (PD) patients and 45 normal control subjects was studied with a Phonemic Word Fluency (PWF) task using the letters F, A, and S, a Semantic Word Fluency (SWF) task using the categories animals, boys' names, and states, and an Alternating Word Fluency (AWF) task requiring the person to alternate between colors and occupations, animals and states, and words beginning with C and P. The number of words generated did not differ for trials with F, A, S, or states, but PD patients generated significantly fewer animal names and boys' names. PD patients also generated significantly fewer words on each of the three AWF trials. The PD patients scored 21% lower than the normal control group on the total AWF score, but only 10% lower for the PWF and SWF scores. The greater impairment on the AWF task which requires the use of internal attentional control to rapidly shift mental set can be considered a type of executive functioning deficit. This is consistent with the growing literature suggesting frontal systems dysfunction in PD and with the view that dopaminergic treatment only incompletely restores functioning in the frontostriatal system.

[Administrative perspectives at Sarasota Memorial Hospital]

Sarasota Memorial's Health VISION project goal is to develop an electronic patient record. This requires total reengineering of health care delivery in Sarasota county to provide optimal exchange of aggregate, educational, cost and patient information to hospitals, clinics, offices and homes.

Ultrastructural analysis reveals avoidance conditioning to induce a transient increase in hippocampal dentate spine density in the 6 hour post-training period of consolidation

Concepts underlying memory consolidation invoke change in synapse structure and function. Such concepts relate to change in connectivity pattern enabled by increased synapse number, change in synaptic configuration resulting from overproduction and selective pruning, or structural change in synapse transmission zones. This study undertook the unbiased estimation of learning associated change in dendritic spine number on granule cells in the hippocampal dentate gyrus. Rats were trained to acquire a passive avoidance response after which spine number in the mid-molecular layer of the dorsal dentate gyrus were estimated at increasing post-training times. This showed there to be an increase in spine density with time after training which was initiated at 3 h, and maximal at 6 h. The increase at this latter time was not detected in passive control animals. At 72 h post-training spine density was seen to return to basal levels. These results are consistent with the various models for synapse connectivity change in memory formation whether they relate to altered number or connectivity pattern.

Differential response of cortical plate and ventricular zone cells to GABA as a migration stimulus

A microdissection technique was used to separate differentiated cortical plate (cp) cells from immature ventricular zone cells (vz) in the rat embryonic cortex. The cp population contained >85% neurons (TUJ1(+)), whereas the vz population contained approximately 60% precursors (nestin+ only). The chemotropic response of each population was analyzed in vitro, using an established microchemotaxis assay. Micromolar GABA (1-5 microM) stimulated the motility of cp neurons expressing glutamic acid decarboxylase (GAD), the rate-limiting enzyme in GABA synthesis. In contrast, femtomolar GABA (500 fM) directed a subset of GAD- vz neurons to migrate. Thus, the two GABA concentrations evoked the motility of phenotypically distinct populations derived from different anatomical regions. Pertussis toxin (PTX) blocked GABA-induced migration, indicating that chemotropic signals involve G-protein activation. Depolarization by micromolar muscimol, elevated [K+]o, or micromolar glutamate arrested migration to GABA or GABA mimetics, indicating that migration is inhibited in the presence of excitatory stimuli. These results suggest that GABA, a single ligand, can promote motility via G-protein activation and arrest attractant-induced migration via GABAA receptor-mediated depolarization.

Studies on the teratogen pharmacophore of valproic acid analogues: evidence of interactions at a hydrophobic centre

Propyl-4-yn-valproic acid (2-propyl-4-pentynoic acid), an analogue of valproic acid with a triple bond in one alkyl side chain, potently induces exencephaly in mice. Given that propyl-4-yn-valproic acid is a branched chain carboxylic acid, we synthesized a series of analogues with n-alkyl side chains of increasing length and correlated their potential to induce neural tube defects and to inhibit proliferation and induce differentiation in cells of neural origin, the latter being crucial to the orderly structuring of the embryo. All analogues significantly increased the incidence of neural tube defects in the embryos of dams exposed to a single dose of 1.25 mmol/kg on day 8 of gestation. This effect occurred in a dose-dependent manner and the rate of exencephaly increased with the progressive increase in n-alkyl side chain length. Moreover, increasing chain length resulted in a dose-dependent inhibition of C6 glioma proliferation rate over a concentration range of 0-3 mM and this was independent of the cell type employed and mode of estimating proliferative rate. The antiproliferative action of these analogues was associated with profound shape change in neuro-2A neuroblastoma involving extensive neuritogenesis and an associated increase in neural cell adhesion molecule (NCAM) prevalence at points of cell-cell contact, the latter exhibiting a dose-dependent increase when the n-alkyl chain was extended to five carbon units. These results suggest an interaction with a specific site in which the n-alkyl side is proposed to serve as an 'anchor' within a hydrophobic pocket to facilitate the ionic and/or H-bonding of the carboxylic acid and high electron density of the carbon-carbon triple bond.

Total prostate and transition zone volumes, and transition zone index are poorly correlated with objective measures of clinical benign prostatic hyperplasia

PURPOSE

We determined if total prostate volume, transition zone volume or transition zone index is correlated with the severity of clinical benign prostatic hyperplasia (BPH).

MATERIALS AND METHODS

A total of 93 men 52 to 85 years old, who were referred to a urology outpatient facility for treatment of clinical BPH, elevated serum prostate specific antigen or abnormal digital rectal examination, underwent measurement of total prostate and transition zone volume at transrectal ultrasonography. All men were requested to undergo uroflowmetry and complete the American Urological Association (AUA) symptom score.

RESULTS

The pairwise correlations between AUA symptom score, versus total prostate and transition zone volumes and transition zone index were not statistically or clinically significant. A weak pairwise relationship was observed between peak flow rate versus total prostate volume (r2 = 0.160), transition zone volume (r2 = 0.156) and transition zone index (r2 = 0.147). The pairwise relationships between AUA symptom scores versus all prostate volumes were not statistically significant for subjects with mild (score 8 or less) or moderate to severe (score more than 8) symptoms.

CONCLUSIONS

Total prostate and transition zone volumes, and transition zone index are not directly related to AUA symptom score and only weakly related to peak flow rate. These findings provide further evidence that the total prostate, total BPH and relative BPH volumes are not useful determinants of the severity of clinical BPH.

Effect of terazosin on prostatism in men with normal and abnormal peak urinary flow rates

OBJECTIVES

To determine if men with normal peak urinary flow rates (PFR) and prostatism respond to terazosin.

METHODS

Forty-one men over the age of 50 years with an American Urological Association (AUA) symptom score greater than 8, postvoid residual urine volume (PVR) less than 300 mL, and no clinical or biochemical evidence of prostate cancer were treated with terazosin independent of the baseline PFR. The effect of terazosin on the AUA symptom score and PFR were compared for subjects with a PFR of 15 mL/s or less (group I) and those with a PFR greater than 15 mL/s (group II).

RESULTS

The baseline age, AUA symptom score, prostate volume, and PVR were not significantly different between the two groups. The mean changes in AUA symptom score were -45.0% and -49.5% for groups I and II, respectively. The mean changes in PFR were 7.0% and -26.6% for groups I and II, respectively.

CONCLUSIONS

The effect of terazosin on AUA symptom score is independent of baseline PFR, indicating that the mechanism of action of terazosin is not exclusively mediated by reduction of bladder outlet obstruction. Randomized controlled studies are required to confirm this provocative observation.

Transient, learning-induced ultrastructural change in spatially-clustered dentate granule cells of the adult rat hippocampus

In semithin, Toluidine Blue-stained plastic coronal sections, we have observed hyperchromatic granule cells in the dorsal crest of the adult rat dentate gyrus following passive avoidance learning. These exhibited a time-dependent, twenty- to thirty-fold increase in their frequency at the 5-7 h post-training time. The hyperchromatic cells formed a rostral-caudal ribbon, 250 microns in diameter and 60 microns in depth, in sections obtained from -2.6 to -4.5 mm with respect to bregma. This was not observed in passive animals or yoked controls. Ultrastructural analysis revealed their cytoplasm and dendrites to be enriched in ribosomes and microtubules, respectively. Dendrites associated with the hyperchromatic cells exhibited a two-fold increase in spine number as compared to those of normochromatic cells in the same region of the dorsal mid-molecular layer. These changes are suggested to be associated with modulation of L1 and neural cell adhesion molecule-mediated neuroplastic change within this discrete post-training period of memory consolidation.