Association Between Common Urologic Medications and Onset of Alzheimer's Disease and Related Dementias in Men With Prostate Cancer Managed by Different Primary Treatment Modalities

OBJECTIVE

To understand the relationship between common urologic medications phosphodiesterase-5 inhibitors (PDE5i) and anticholinergics (AC) and risk of dementia onset in men who underwent different primary treatments for prostate cancer.

MATERIALS AND METHODS

Patients (>50years) with prostate cancer (1998-2022) without Alzheimer's disease or related dementias were selected from Cancer of the Prostatic Strategic Urologic Research Endeavor Registry. Minimum medication use was 3months. Fine-Gray regression was performed to determine the association between medication exposure and dementia onset ≥12months after primary treatment in men matched on age, race, comorbid conditions, smoking, and type of clinical site, with competing risk of death.

RESULTS

Among 5937 men (53% PDE5i; 14% AC), PDE5i users were younger (63 vs 70, P < .01) with less CAD, CVA, DM (all P < .01); AC users were older (68 vs 66, P < .01) with higher incidence of comorbidities (P < .01). Median months of use was 24.3 (IQR 12.1, 48.7) for PDE5i and 12.2 (IQR 6.1, 24.3) for AC users. Cumulative incidence of Alzheimer's disease or related dementias was 6.5% at 15years. PDE5i (P = .07) and AC (P = .06) were not associated with dementia regardless of primary treatment modality.

CONCLUSION

In this retrospective cohort study, PDE5i and AC use do not appear independently associated with risk of dementia. Notably, our cohort was generally healthy and younger which may limit our ability to detect significance. We recommend prospective investigation into association between PDE5i and dementia and advise continued judicious stewardship of AC in older patient populations.

Expression of the transcription factor Klf6 by thymic epithelial cells is required for thymus development

Thymic epithelial cells (TEC) control T cell development and play essential roles in establishing self-tolerance. By using Foxn1-Cre-driven ablation of Klf6 gene in TEC, we identified Klf6 as a critical factor in TEC development. Klf6 deficiency resulted in a hypoplastic thymus-evident from fetal stages into adulthood-in which a dramatic increase in the frequency of apoptotic TEC was observed. Among cortical TEC (cTEC), a previously unreported cTEC population expressing the transcription factor Sox10 was relatively expanded. Within medullary TEC (mTEC), mTEC I and Tuft-like mTEC IV were disproportionately decreased. Klf6 deficiency altered chromatin accessibility and affected TEC chromatin configuration. Consistent with these defects, naïve conventional T cells and invariant natural killer T cells were reduced in the spleen. Late stages of T cell receptor-dependent selection of thymocytes were affected, and mice exhibited autoimmunity. Thus, Klf6 has a prosurvival role and affects the development of specific TEC subsets contributing to thymic function.

Impact of Stress Urinary Incontinence After Radical Prostatectomy on Time to Intervention, Quality of Life and Work Status

OBJECTIVE

To characterize the incidence of stress urinary incontinence (SUI) after radical prostatectomy (RP), its treatment, and impact on quality of life (QoL) and work status 1year after RP.

MATERIALS AND METHODS

Prostate cancer patients treated by RP (1998-2016) were selected from CaPSURE. SUI was defined as any pads per day (ppd) 1 year after RP. SUI procedures were tracked by CPT codes (sling and artificial sphincter). Patients reported work status (full-time, part-time, unpaid), UCLA PCa Index urinary function (UF) and bother (UB) and SF36 Index physical function (PF). Associations of incontinence with UF, UB, and PF and work status changes were assessed (ANOVA). Lifetable estimates and Cox proportional hazards regression evaluated risk of undergoing SUI procedures.

RESULTS

664/2989 (22%) men treated with RP reported SUI at 1 year. More men with SUI had ≥GG2, intermediate to high-risk disease and non-nerve-sparing surgery (all P < .01). Cumulative incidence of SUI procedures was 1.4% at 10years after RP. Age (HR 2.68 per 10years, 95% CI 1.41-5.08) and number of ppd at 1 year (HR 3.20, 95% CI 2.27-4.50) were associated with undergoing SUI procedures. UF declined at 1year after RP, while UB and PF remained stable. UF, UB, and PF were inversely associated with number of ppd (all P < .01). Change in work status was not associated with incontinence or QoL scores.

CONCLUSION

Incontinence affected QoL without impacting work status, suggesting that men with SUI after RP may continue working and go under-treated despite impact on QoL.

Revelations in Thymic Epithelial Cell Biology and Heterogeneity from Single-Cell RNA Sequencing and Lineage Tracing Methodologies

Thymic epithelial cells (TECs) make up the thymic microenvironments that support the generation of a functionally competent and self-tolerant T-cell repertoire. Cortical (c)TECs, present in the cortex, are essential for early thymocyte development including selection of thymocytes expressing functional TCRs (positive selection). Medullary (m)TECs, located in the medulla, play a key role in late thymocyte development, including depletion of self-reactive T cells (negative selection) and selection of regulatory T cells. In recent years, transcriptomic analysis by single-cell (sc)RNA sequencing (Seq) has revealed TEC heterogeneity previously masked by population-level RNA-Seq or phenotypic studies. We summarize the discoveries made possible by scRNA-Seq, including the identification of novel mTEC subsets, advances in understanding mTEC promiscuous gene expression, and TEC alterations from embryonic to adult stages. Whereas pseudotime analyses of scRNA-Seq data can suggest relationships between TEC subsets, experimental methods such as lineage tracing and reaggregate thymic organ culture (RTOC) are required to test these hypotheses. Lineage tracing - namely, of β5t or Aire expressing cells - has exposed progenitor and parent-daughter cellular relationships within TEC.

Diversity in Cortical Thymic Epithelial Cells Occurs through Loss of a Foxn1-Dependent Gene Signature Driven by Stage-Specific Thymocyte Cross-Talk

In the thymus, cortical thymic epithelial cells (cTECs) and medullary thymic epithelial cells support αβT cell development from lymphoid progenitors. For cTECs, expression of a specialized gene signature that includes Cxcl12, Dll4, and Psmb11 enables the cortex to support T lineage commitment and the generation and selection of CD4+CD8+ thymocytes. Although the importance of cTECs in T cell development is well defined, mechanisms that shape the cTEC compartment and regulate its functional specialization are unclear. Using a Cxcl12DsRed reporter mouse model, we show that changes in Cxcl12 expression reveal a developmentally regulated program of cTEC heterogeneity. Although cTECs are uniformly Cxcl12DsRed+ during neonatal stages, progression through postnatal life triggers the appearance of Cxcl12DsRed- cTECs that continue to reside in the cortex alongside their Cxcl12DsRed+ counterparts. This appearance of Cxcl12DsRed- cTECs is controlled by maturation of CD4-CD8-, but not CD4+CD8+, thymocytes, demonstrating that stage-specific thymocyte cross-talk controls cTEC heterogeneity. Importantly, although fate-mapping experiments show both Cxcl12DsRed+ and Cxcl12DsRed- cTECs share a common Foxn1+ cell origin, RNA sequencing analysis shows Cxcl12DsRed- cTECs no longer express Foxn1, which results in loss of the FOXN1-dependent cTEC gene signature and may explain the reduced capacity of Cxcl12DsRed- cTECs for thymocyte interactions. In summary, our study shows that shaping of the cTEC compartment during the life course occurs via stage-specific thymocyte cross-talk, which drives loss of Foxn1 expression and its key target genes, which may then determine the functional competence of the thymic cortex.

Trust your gut: an early life lesson for T cells

Zegarra-Ruiz et al. demonstrate that gut microbe-specific T cells are selected within the thymus exclusively during early life in mice. This selection is dependent on CX3CR1⁺ dendritic cells migrating from the gut carrying bacterially derived antigens into the thymus. This offers new insight into how gut microbiota influence T cell development.

Postnatal Involution and Counter-Involution of the Thymus

Thymus involution occurs in all vertebrates. It is thought to impact on immune responses in the aged, and in other clinical circumstances such as bone marrow transplantation. Determinants of thymus growth and size are beginning to be identified. Ectopic expression of factors like cyclin D1 and Myc in thymic epithelial cells (TEC)s results in considerable increase in thymus size. These models provide useful experimental tools that allow thymus function to be understood. In future, understanding TEC-specific controllers of growth will provide new approaches to thymus regeneration.

Myc controls a distinct transcriptional program in fetal thymic epithelial cells that determines thymus growth

Interactions between thymic epithelial cells (TEC) and developing thymocytes are essential for T cell development, but molecular insights on TEC and thymus homeostasis are still lacking. Here we identify distinct transcriptional programs of TEC that account for their age-specific properties, including proliferation rates, engraftability and function. Further analyses identify Myc as a regulator of fetal thymus development to support the rapid increase of thymus size during fetal life. Enforced Myc expression in TEC induces the prolonged maintenance of a fetal-specific transcriptional program, which in turn extends the growth phase of the thymus and enhances thymic output; meanwhile, inducible expression of Myc in adult TEC similarly promotes thymic growth. Mechanistically, this Myc function is associated with enhanced ribosomal biogenesis in TEC. Our study thus identifies age-specific transcriptional programs in TEC, and establishes that Myc controls thymus size.

Identification of an Intronic Regulatory Element Necessary for Tissue-Specific Expression of Foxn1 in Thymic Epithelial Cells

The thymus is critical for the establishment of the adaptive immune system and the development of a diverse T cell repertoire. T cell development depends upon cell-cell interactions with epithelial cells in the thymus. The thymus is composed of two different types of epithelial cells: cortical and medullary epithelial cells. Both of these express and critically depend on the transcription factor Foxn1 Foxn1 is also expressed in the hair follicle, and disruption of Foxn1 function in mice results in severe thymic developmental defects and the hairless (nude) phenotype. Despite its importance, little is known about the direct regulation of Foxn1 expression. In this study, we identify a cis-regulatory element (RE) critical for expression of Foxn1 in mouse thymic epithelial cells but dispensable for expression in hair follicles. Analysis of chromatin accessibility, histone modifications, and sequence conservation identified regions within the first intron of Foxn1 that possessed the characteristics of REs. Systematic knockout of candidate regions lead us to identify a 1.6 kb region that, when deleted, results in a near total disruption of thymus development. Interestingly, Foxn1 expression and function in the hair follicle were unaffected. RNA fluorescent in situ hybridization showed a near complete loss of Foxn1 mRNA expression in the embryonic thymic bud. Our studies have identified a genomic RE with thymic-specific control of Foxn1 gene expression.

Aire controls the recirculation of murine Foxp3+ regulatory T-cells back to the thymus

In the thymus, medullary thymic epithelial cells (mTEC) determine the fate of newly selected CD4+ and CD8+ single positive (SP) thymocytes. For example, mTEC expression of Aire controls intrathymic self-antigen availability for negative selection. Interestingly, alterations in both Foxp3+ Regulatory T-cells (T-Reg) and conventional SP thymocytes in Aire-/- mice suggest additional, yet poorly understood, roles for Aire during intrathymic T-cell development. To examine this, we analysed thymocytes from Aire-/- mice using Rag2GFP and Foxp3 expression, and a recently described CD69/MHCI subset definition of post-selection CD4+ conventional thymocytes. We show that while Aire is dispensable for de novo generation of conventional αβT-cells, it plays a key role in controlling the intrathymic T-Reg pool. Surprisingly, a decline in intrathymic T-Reg in Aire-/- mice maps to a reduction in mature recirculating Rag2GFP- T-Reg that express CCR6 and re-enter the thymus from the periphery. Furthermore, we show mTEC expression of the CCR6 ligand CCL20 is reduced in Aire-/- mice, and that CCR6 is required for T-Reg recirculation back to the thymus. Collectively, our study re-defines requirements for late stage intrathymic αβT-cell development, and demonstrates that Aire controls a CCR6-CCL20 axis that determines the developmental makeup of the intrathymic T-Reg pool.

CCR7 Controls Thymus Recirculation, but Not Production and Emigration, of Foxp3(+) T Cells

Current models of Foxp3⁺ regulatory T cell (Treg) development involve CCR7-mediated migration of thymocytes into the thymus medulla to enable essential interactions with medullary epithelium. However, increased Foxp3⁺ thymic Treg numbers in Ccr7^−/− mice challenge this view, and the role of CCR7 in Treg development, emigration, and/or recirculation is unknown. Here, we have examined CCR7 and Rag2pGFP levels during Treg development and generated Rag2pGFPCcr7^−/− mice to study its impact on the intrathymic Treg pool. We reveal surprising developmental heterogeneity in thymocytes described as Treg precursors, showing that they contain recirculating CCR6⁺CCR7⁻Rag2pGFP⁻ T cells. Although CCR7 defines bona fide Rag2GFP⁺ Treg precursors, it is not required for Treg production and emigration. Rather, we show that lack of CCR7 renders the thymus more receptive to Treg thymus homing. Our study reveals a role for CCR7 in limiting Treg recirculation back to the thymus and enables separation of the mechanisms controlling Treg production and thymic recirculation.

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Chemokine receptors define recirculating and newly selected Tregs

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CCR7 is dispensable for Treg development and thymus egress

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CCR7 is required to rate-limit the thymus recirculation of peripheral CCR6⁺ Tregs

Osteoprotegerin-Mediated Homeostasis of Rank+ Thymic Epithelial Cells Does Not Limit Foxp3+ Regulatory T Cell Development

In the thymus, medullary thymic epithelial cells (mTEC) regulate T cell tolerance via negative selection and Foxp3(+) regulatory T cell (Treg) development, and alterations in the mTEC compartment can lead to tolerance breakdown and autoimmunity. Both the receptor activator for NF-κB (RANK)/RANK ligand (RANKL)/osteoprotegerin (OPG) axis and expression of the transcriptional regulator Aire are involved in the regulation of thymus medullary microenvironments. However, their impact on the mechanisms controlling mTEC homeostasis is poorly understood, as are the processes that enable the thymus medulla to support the balanced production of mTEC-dependent Foxp3(+) Treg. In this study, we have investigated the control of mTEC homeostasis and examined how this process impacts the efficacy of Foxp3(+) Treg development. Using newly generated RANK Venus reporter mice, we identify distinct RANK(+) subsets that reside within both the mTEC(hi) and mTEC(lo) compartments and that represent direct targets of OPG-mediated control. Moreover, by mapping OPG expression to a subset of Aire(+) mTEC, our data show how cis- and trans-acting mechanisms are able to control the thymus medulla by operating on multiple mTEC targets. Finally, we show that whereas the increase in mTEC availability in OPG-deficient (Tnfrsf11b(-/-)) mice impacts the intrathymic Foxp3(+) Treg pool by enhancing peripheral Treg recirculation back to the thymus, it does not alter the number of de novo Rag2pGFP(+)Foxp3(+) Treg that are generated. Collectively, our study defines patterns of RANK expression within the thymus medulla, and it shows that mTEC homeostasis is not a rate-limiting step in intrathymic Foxp3(+) Treg production.

Natural Th17 cells are critically regulated by functional medullary thymic microenvironments

The thymic medulla is critical for the enforcement of central tolerance. In addition to deletion of auto-reactive T-cells, the thymic medulla supports the maturation of heterogeneous natural αβT-cells linked to tolerance mechanisms. Natural IL-17-secreting CD4(+)αβT-cells (nTh17) represent recently described natural αβT-cells that mature and undergo functional priming intrathymically. Despite a proposed potential to impact upon either protective or pathological inflammatory responses, the intrathymic mechanisms regulating the balance of nTh17 development are unclear. Here we compare the development of distinct natural αβT-cells in the thymus. We reveal that thymic stromal MHC class II expression and RelB-dependent medullary thymic epithelial cells (mTEC), including Aire(+) mTEC, are an essential requirement for nTh17 development. nTh17 demonstrate a partial, non-redundant requirement for both ICOS-ligand and CD80/86 costimulation, with a dispensable role for CD80/86 expression by thymic epithelial cells. Although mTEC constitutively expressed inducible nitric oxide synthase (iNOS), a critical negative regulator of conventional Th17 differentiation, iNOS was not essential to constrain thymic nTh17. These findings highlight the critical role of the thymic medulla in the differential regulation of novel natural αβT-cell subsets, and reveal additional layers of thymic medullary regulation of T-cell driven autoimmunity and inflammation.

Thymus medulla fosters generation of natural Treg cells, invariant γδ T cells, and invariant NKT cells: what we learn from intrathymic migration

The organization of the thymus into distinct cortical and medullary regions enables it to control the step-wise migration and development of immature T-cell precursors. Such a process provides access to specialized cortical and medullary thymic epithelial cells at defined stages of maturation, ensuring the generation of self-tolerant and MHC-restricted conventional CD4⁺ and CD8⁺ αβ T cells. The migratory cues and stromal cell requirements that regulate the development of conventional αβ T cells have been well studied. However, the thymus also fosters the generation of several immunoregulatory T-cell populations that form key components of both innate and adaptive immune responses. These include Foxp3⁺ natural regulatory T cells, invariant γδ T cells, and CD1d-restricted invariant natural killer T cells (iNKT cells). While less is known about the intrathymic requirements of these nonconventional T cells, recent studies have highlighted the importance of the thymus medulla in their development. Here, we review recent findings on the mechanisms controlling the intrathymic migration of distinct T-cell subsets, and relate this to knowledge of the microenvironmental requirements of these cells.

Untreated Gleason Grade Progression on Serial Biopsies during Prostate Cancer Active Surveillance: Clinical Course and Pathological Outcomes

PURPOSE

We describe the outcomes of patients with low risk localized prostate cancer who were upgraded on a surveillance biopsy while on active surveillance and evaluated whether delayed treatment was associated with adverse outcome.

MATERIALS AND METHODS

We included men in the study with lower risk disease managed initially with active surveillance and upgraded to Gleason score 3+4 or greater. Patient demographics and disease characteristics were compared. Kaplan-Meier curve was used to estimate the treatment-free probability stratified by initial upgrade (3+4 vs 4+3 or greater), Cox regression analysis was used to examine factors associated with treatment and multivariate logistic regression analysis was used to evaluate the factors associated with adverse outcome at surgery.

RESULTS

The final cohort comprised 219 men, with 150 (68%) upgraded to 3+4 and 69 (32%) to 4+3 or greater. Median time to upgrade was 23 months (IQR 11-49). A total of 163 men (74%) sought treatment, the majority (69%) with radical prostatectomy. The treatment-free survival rate at 5 years was 22% for 3+4 and 10% for 4+3 or greater upgrade. Upgrade to 4+3 or greater, higher prostate specific antigen density at diagnosis and shorter time to initial upgrade were associated with treatment. At surgical pathology 34% of cancers were downgraded while 6% were upgraded. Cancer volume at initial upgrade was associated with adverse pathological outcome at surgery (OR 3.33, 95% CI 1.19-9.29, p=0.02).

CONCLUSIONS

After Gleason score upgrade most patients elected treatment with radical prostatectomy. Among men who deferred definitive intervention, few experienced additional upgrading. At radical prostatectomy only 6% of cases were upgraded further and only tumor volume at initial upgrade was significantly associated with adverse pathological outcome.

Differential requirement for CCR4 and CCR7 during the development of innate and adaptive αβT cells in the adult thymus

αβT cell development depends upon serial migration of thymocyte precursors through cortical and medullary microenvironments, enabling specialized stromal cells to provide important signals at specific stages of their development. Although conventional αβT cells are subject to clonal deletion in the medulla, entry into the thymus medulla also fosters αβT cell differentiation. For example, during postnatal periods, the medulla is involved in the intrathymic generation of multiple αβT cell lineages, notably the induction of Foxp3(+) regulatory T cell development and the completion of invariant NKT cell development. Although migration of conventional αβT cells to the medulla is mediated by the chemokine receptor CCR7, how other T cell subsets gain access to medullary areas during their normal development is not clear. In this study, we show that combining a panel of thymocyte maturation markers with cell surface analysis of CCR7 and CCR4 identifies distinct stages in the development of multiple αβT cell lineages in the thymus. Although Aire regulates expression of the CCR4 ligands CCL17 and CCL22, we show that CCR4 is dispensable for thymocyte migration and development in the adult thymus, demonstrating defective T cell development in Aire(-/-) mice is not because of a loss of CCR4-mediated migration. Moreover, we reveal that CCR7 controls the development of invariant NKT cells by enabling their access to IL-15 trans-presentation in the thymic medulla and influences the balance of early and late intrathymic stages of Foxp3(+) regulatory T cell development. Collectively, our data identify novel roles for CCR7 during intrathymic T cell development, highlighting its importance in enabling multiple αβT cell lineages to access the thymic medulla.

An essential role for medullary thymic epithelial cells during the intrathymic development of invariant NKT cells

In the thymus, interactions with both cortical and medullary microenvironments regulate the development of self-tolerant conventional CD4(+) and CD8(+) αβT cells expressing a wide range of αβTCR specificities. Additionally, the cortex is also required for the development of invariant NKT (iNKT) cells, a specialized subset of T cells that expresses a restricted αβTCR repertoire and is linked to the regulation of innate and adaptive immune responses. Although the role of the cortex in this process is to enable recognition of CD1d molecules expressed by CD4(+)CD8(+) thymocyte precursors, the requirements for additional thymus microenvironments during iNKT cell development are unknown. In this study, we reveal a role for medullary thymic epithelial cells (mTECs) during iNKT cell development in the mouse thymus. This requirement for mTECs correlates with their expression of genes required for IL-15 trans-presentation, and we show that soluble IL-15/IL-15Rα complexes restore iNKT cell development in the absence of mTECs. Furthermore, mTEC development is abnormal in iNKT cell-deficient mice, and early stages in iNKT cell development trigger receptor activator for NF-κB ligand-mediated mTEC development. Collectively, our findings demonstrate that intrathymic iNKT cell development requires stepwise interactions with both the cortex and the medulla, emphasizing the importance of thymus compartmentalization in the generation of both diverse and invariant αβT cells. Moreover, the identification of a novel requirement for iNKT cells in thymus medulla development further highlights the role of both innate and adaptive immune cells in thymus medulla formation.

The thymic medulla is required for Foxp3+ regulatory but not conventional CD4+ thymocyte development

A key role of the thymic medulla is to negatively select autoreactive CD4(+) and CD8(+) thymocytes, a process important for T cell tolerance induction. However, the involvement of the thymic medulla in other aspects of αβ T cell development, including the generation of Foxp3(+) natural regulatory T cells (nTreg cells) and the continued maturation of positively selected conventional αβ T cells, is unclear. We show that newly generated conventional CD69(+)Qa2(-) CD4 single-positive thymocytes mature to the late CD69(-)Qa2(+) stage in the absence of RelB-dependent medullary thymic epithelial cells (mTECs). Furthermore, an increasing ability to continue maturation extrathymically is observed within the CD69(+)CCR7(-/lo)CCR9(+) subset of conventional SP4 thymocytes, providing evidence for an independence from medullary support by the earliest stages after positive selection. In contrast, Foxp3(+) nTreg cell development is medullary dependent, with mTECs fostering the generation of Foxp3(-)CD25(+) nTreg cell precursors at the CD69(+)CCR7(+)CCR9(-) stage. Our results demonstrate a differential requirement for the thymic medulla in relation to CD4 conventional and Foxp3(+) thymocyte lineages, in which an intact mTEC compartment is a prerequisite for Foxp3(+) nTreg cell development through the generation of Foxp3(-)CD25(+) nTreg cell precursors.

Active surveillance: does serial prostate biopsy increase histological inflammation?

BACKGROUND

Active surveillance (AS) is an appropriate management strategy for men with low-risk prostate cancer. Most protocols recommend repeated prostate biopsy every 12-24 months. The purpose of this paper is to describe histological inflammation patterns in men on AS who underwent serial prostate biopsy for disease monitoring.

METHODS

We reviewed records of men on AS from January 1999 through February 2011 who had a diagnostic plus ≥1 repeat transrectal ultrasound-guided biopsies performed at our institution. The type and degree of inflammatory infiltrate were grossly reviewed and scored for each patient's biopsy by a single pathologist. Relationship of inflammation severity and number of serial biopsies was assessed using a repeated measures mixed model. Unpaired t-test and χ(2)-square analysis assessed variance in degree of inflammation and location of inflammation relative to cancer grade progression defined as Gleason sum increase.

RESULTS

Fifty-six men met study inclusion criteria. Mean age was 62.1 (6.5) years, 71% were stage cT1c, 79% had a PSA level <10 ng ml(-1), and 98% had diagnostic Gleason sum ≤6. A small, statistically significant increase in maximum chronic inflammation (CI) scores with greater number of repeat biopsies was observed. CI scores were not associated with number of biopsies based on upgrade status. The main limitation to our study is our small sample size. Potential unmeasured confounders, such as unreported antibiotic use or symptomatic prostatitis, may have also affected our findings.

CONCLUSIONS

In this pilot study of 56 men on AS for localized prostate cancer, degree of chronic histological inflammation increased with greater number of prostate biopsies, but was not associated with subsequent risk of grade progression.

PSA screening: determinants of primary-care physician practice patterns

BACKGROUND

The effect of practice guidelines and the European Randomised Screening for Prostate Cancer (ERSPC) and Prostate, Lung, Colorectal and Ovarian (PLCO) trials on PSA screening practices of primary-care physicians (PCPs) is unknown.

METHODS

We conducted a national cross-sectional on-line survey of a random sample of 3010 PCPs from July to August 2010. Participants were queried about their knowledge of prostate cancer, PSA screening guidelines, the ERSPC and PLCO trials, and about their PSA screening practices. Factors associated with PSA screening were identified using multivariable linear regression.

RESULTS

A total of 152 (5%) participants opened and 89 completed the on-line survey, yielding a response rate of 58% for those that viewed the invitation. Eighty percent of respondents correctly identified prostate cancer risk factors. In all, 51% and 64% reported that they discuss and order PSA screening for men aged 50-75 years, respectively. Fifty-four percent were most influenced by the US Preventative Services Task Force (USPSTF) guidelines. Also, 21% and 28% of respondents stated that their PSA screening practices were influenced by the ERSPC and PLCO trials, respectively. Medical specialty was the only variable associated with propensity to screen, with family medicine physicians more likely to use PSA screening than internists (β=0.21, P=0.02).

CONCLUSIONS

Half of the physicians surveyed did not routinely discuss PSA screening with eligible patients. The impact of the ERSPC and PLCO trials on PSA screening practices was low among US PCPs. USPSTF recommendations for PSA screening continue to be the strongest influence on PCPs' propensity to use PSA screening.

Effects of elevated CO2 on intra-specific competition in Sinapis alba: an examination of the role of growth responses to red:far-red ratio

Response of plants to elevated CO2 differs markedly between individually- and competitively-grown plants, both in terms of mean size and variation about the mean. Using Sinapis alba, we explored whether these contrasting effects are a consequence of the effect of competition on the red:far red (R:FR) light ratio. Plants were grown at both ambient and elevated (700 microl.l(-1)) CO2 in competitive stands, and as individuals at either a low (0.7) or high (1.25) R:FR ratio at a constant photosynthetic photon fluence rate. Elevated CO2 increased stand biomass by enhancing the growth of canopy dominants, but not the subordinates. As a consequence, elevated CO2 increased the coefficient of variation in size within the stands. Elevated CO2 did not enhance the growth of individually-grown plants at the low R:FR ratio, but did at the high R:FR ratio. Both the poor response of subordinate plants to elevated CO2 and the increased size inequalities of individuals within the stand can be explained in terms of the effect of the R:FR ratio on CO2 responsiveness. The effect of the R:FR ratio on CO2 response may be related to its effect on allocation patterns and nutrient uptake.

Quality of life in young men after radical prostatectomy

Urinary and sexual function and bother are important outcomes following radical prostatectomy (RP). Since urinary and sexual function are age-related, post-operative bother may vary by age. This study explores the disease-specific quality-of-life outcomes in young men compared with older men undergoing RP. Using CaPSURE data, we identified men who underwent RP and completed the UCLA Prostate Cancer Index (PCI) before and 1-year post-RP. Men were stratified by age (< 55 years, 55-64, > or = 65). Multivariate regression models were created: a linear model for predictors of PCI scores and a logistic model for predictors of severe declines in PCI domains. Younger men scored significantly better than older men in urinary function (P=0.04), urinary bother (P=0.02) and sexual function (P<0.0001) 1-year post-RP. Severe declines in urinary bother (odds ratio (OR)=1.54, 1.01-2.35) and sexual function (OR=3.20, 1.97-5.19) were more common in men > or = 65 years. Men with relationships had less urinary bother (P=0.03) and were less likely to experience severe worsening of urinary bother (OR=0.32, 0.17-0.60) while having a greater risk of severe worsening of sexual bother (OR=2.74, 1.28-5.89). The use of sexual aids was associated with worse sexual bother (P<0.0001) and greater risk of severe worsening of sexual bother (OR=2.29, 1.54-3.30). Baseline PCI scores were independent predictors in all models. One year after RP, younger men (age < 55) have similar, or better, urinary and sexual function and bother. Baseline scores are strongly associated with post-RP scores and severity of declines. Current relationships and use of sexual aids have significant roles in post-RP bother.

Arch-length asymmetry related to an odontoma in a three-year-old

Odontomas are often discovered after they affect the eruption and position of the permanent teeth. This case report pointed out that as early as thirty months the primary dentition can be altered.

A voluntary serosurvey and behavioral risk assessment for human immunodeficiency virus infection among college students

The authors conducted a voluntary serosurvey and educational campaign among 3394 undergraduate students attending the University of Maryland at College Park to determine the prevalence of and risk factors for human immunodeficiency virus type 1 (HIV-1) infection. Two students were seropositive (0.06%, 95% confidence interval 0-0.15%). Both were homosexual men with multiple sexual partners. Despite the low prevalence of infection, potential risk factors for transmission of HIV-1 were common, as assessed by a self-administered anonymous questionnaire. These included a previous sexually transmitted disease (12.6%), male homosexual intercourse (4.8% of men), heterosexual anal intercourse (25.3%), heterosexual intercourse with a person at risk (an HIV-1 infected person, a bisexual man, a parenteral drug user, a female prostitute, or a hemophiliac) (5.2%), multiple sexual partners (21% reported 10 or more lifetime partners), and intravenous drug use (1.3%). Assessment of the efficacy of our program by comparing responses on pre- and post-test questionnaires showed gains in knowledge about heterosexual transmission of HIV-1 and an increase in the reported frequency of condom use 1-2 months after participating in the survey. The authors conclude that HIV-1 infections are occurring among college students but in our study group remain confined to persons with known high-risk behavior; however, practices that may support transmission are common, and programs designed to diminish these behaviors among college students are needed.

Assessment of the prevalence and risk factors for human immunodeficiency virus type 1 (HIV-1) infection among college students using three survey methods

To evaluate the seroprevalence and risk factors for human immunodeficiency virus type 1 (HIV-1) infection among undergraduate college students, the authors simultaneously conducted three types of surveillance on a large university campus (27,902 undergraduates) in the Baltimore-Washington metropolitan area: a voluntary HIV-1 serosurvey with a linked risk assessment questionnaire (n = 3,394), a blinded serosurvey using blood specimens collected for routine purposes in the Student Health Center (n = 1,829), and a random sample risk assessment and case identification mail survey (n = 1,017 respondents of 3,000 solicited). The proportion of students belonging to a known risk group (a homosexual or bisexual man, intravenous drug user, or a sexual partner of a bisexual man, an HIV-1-infected person, a female prostitute, or an intravenous drug user) was 5.9% in the mail survey and 8.8% in the voluntary serosurvey. Whereas no infections were detected in the blinded serosurvey, two infected persons were identified in the mail survey (0.2%) and two in the voluntary serosurvey (0.06%), all among high-risk persons. Although derived from independent samples and subject to different biases, these three survey methods yielded a consistent pattern of HIV-1 epidemiology on this campus, whereby the overall prevalence of infection was low and confined to members of high-risk groups, despite the common occurrence of behaviors that might facilitate sexual transmission of HIV-1 among many other students.