Virtual reality as a method of cognitive training of processing speed, working memory, and sustained attention in persons with acquired brain injury: a protocol for a randomized controlled trial

BACKGROUND

Acquired brain injury (ABI) often leads to persisting somatic, cognitive, and social impairments. Cognitive impairments of processing speed, sustained attention, and working memory are frequently reported and may negatively affect activities of daily living and quality of life. Rehabilitation efforts aiming to retrain these cognitive functions have often consisted of computerized training programs. However, few studies have demonstrated effects that transfer beyond the trained tasks. There is a growing optimism regarding the potential usefulness of virtual reality (VR) in cognitive rehabilitation. The research literature is sparse, and existing studies are characterized by considerable methodological weaknesses. There is also a lack of knowledge about the acceptance and tolerability of VR as an intervention method for people with ABI. The present study aims to investigate whether playing a commercially available VR game is effective in training cognitive functions after ABI and to explore if the possible effects transfer into everyday functioning.

METHODS

One hundred participants (18-65 years), with a verified ABI, impairments of processing speed/attention, and/or working memory, and a minimum of 12 months post injury will be recruited. Participants with severe aphasia, apraxia, visual neglect, epilepsy, and severe mental illness will be excluded. Participants will be randomized into two parallel groups: (1) an intervention group playing a commercial VR game taxing processing speed, working memory, and sustained attention; (2) an active control group receiving psychoeducation regarding compensatory strategies, and general cognitive training tasks such as crossword puzzles or sudoku. The intervention period is 5 weeks. The VR group will be asked to train at home for 30 min 5 days per week. Each participant will be assessed at baseline with neuropsychological tests and questionnaires, after the end of the intervention (5 weeks), and 16 weeks after baseline. After the end of the intervention period, focus group interviews will be conducted with 10 of the participants in the intervention group, in order to investigate acceptance and tolerability of VR as a training method.

DISCUSSION

This study will contribute to improve understanding of how VR is tolerated and experienced by the ABI population. If proven effective, the study can contribute to new rehabilitation methods that persons with ABI can utilize in a home setting, after the post-acute rehabilitation has ended.

A cervical screening initiative for elderly women in Denmark

INTRODUCTION

To assess outcome of a one-time human papillomavirus (HPV)-screening in 2017 of Danish women aged 70+.

MATERIAL AND METHODS

Women born 1947 or before were personally invited to have a cell-sample collected by their general practitioner. Screening- and follow-up samples were analyzed in hospital laboratories in the five Danish regions and registered centrally. Follow-up procedures varied slightly across regions. Cervical intraepithelial neoplasia 2 (CIN2) was recommended treatment threshold. Data were retrieved from the Danish Quality Database for Cervical Cancer Screening. We calculated CIN2+ and CIN3+ detection rates per 1000 screened women, and number of biopsies and conizations per detected CIN2+ case. We tabulated annual number of incident cervical cancer cases in Denmark for the years 2009-2020.

RESULTS

In total, 359 763 women were invited of whom 108 585 (30% of invited) were screened; 4479 (4.1% of screened, and 4.3% of screened 70-74 years) tested HPV-positive; of whom 2419 (54% of HPV-positive) were recommended follow-up with colposcopy, biopsy and cervical sampling, and 2060 with cell-sample follow-up. In total, 2888 women had histology; of whom 1237 cone specimen and 1651 biopsy only. Out of 1000 screened women 11 (95% confidence interval [CI]: 11-12) had conization. In total, 579 women had CIN2+; 209 CIN2, 314 CIN3, and 56 cancer. Out of 1000 screened women five (95% CI: 5-6) had CIN2+. Detection rate of CIN2+ was highest in regions where conization was used as part of first-line follow-up. In 2009-2016, number of incident cervical cancers in women aged 70+ in Denmark fluctuated around 64; in 2017 it reached 83 cases; and by 2021 the number had decreased to 50.

CONCLUSIONS

The prevalence of high-risk HPV of 4.3% in women aged 70-74 is in agreement with data from Australia, and the detection of five CIN+2 cases per 1000 screened women is in agreement with data for 65-69 year old women in Norway. Data are thus starting to accumulate on primary HPV-screening of elderly women. The screening resulted in a prevalence peak in incident cervical cancers, and it will therefore take some years before the cancer preventive effect of the screening can be evaluated.

Carbonic anhydrases reduce the acidity of the tumor microenvironment, promote immune infiltration, decelerate tumor growth, and improve survival in ErbB2/HER2-enriched breast cancer

BACKGROUND

Carbonic anhydrases catalyze CO₂/HCO₃^- buffer reactions with implications for effective H⁺ mobility, pH dynamics, and cellular acid-base sensing. Yet, the integrated consequences of carbonic anhydrases for cancer and stromal cell functions, their interactions, and patient prognosis are not yet clear.

METHODS

We combine (a) bioinformatic analyses of human proteomic data and bulk and single-cell transcriptomic data coupled to clinicopathologic and prognostic information; (b) ex vivo experimental studies of gene expression in breast tissue based on quantitative reverse transcription and polymerase chain reactions, intracellular and extracellular pH recordings based on fluorescence confocal microscopy, and immunohistochemical protein identification in human and murine breast cancer biopsies; and (c) in vivo tumor size measurements, pH-sensitive microelectrode recordings, and microdialysis-based metabolite analyses in mice with experimentally induced breast carcinomas.

RESULTS

Carbonic anhydrases-particularly the extracellular isoforms CA4, CA6, CA9, CA12, and CA14-undergo potent expression changes during human and murine breast carcinogenesis. In patients with basal-like/triple-negative breast cancer, elevated expression of the extracellular carbonic anhydrases negatively predicts survival, whereas, surprisingly, the extracellular carbonic anhydrases positively predict patient survival in HER2/ErbB2-enriched breast cancer. Carbonic anhydrase inhibition attenuates cellular net acid extrusion and extracellular H⁺ elimination from diffusion-restricted to peripheral and well-perfused regions of human and murine breast cancer tissue. Supplied in vivo, the carbonic anhydrase inhibitor acetazolamide acidifies the microenvironment of ErbB2-induced murine breast carcinomas, limits tumor immune infiltration (CD3⁺ T cells, CD19⁺ B cells, F4/80⁺ macrophages), lowers inflammatory cytokine (Il1a, Il1b, Il6) and transcription factor (Nfkb1) expression, and accelerates tumor growth. Supporting the immunomodulatory influences of carbonic anhydrases, patient survival benefits associated with high extracellular carbonic anhydrase expression in HER2-enriched breast carcinomas depend on the tumor inflammatory profile. Acetazolamide lowers lactate levels in breast tissue and blood without influencing breast tumor perfusion, suggesting that carbonic anhydrase inhibition lowers fermentative glycolysis.

CONCLUSIONS

We conclude that carbonic anhydrases (a) elevate pH in breast carcinomas by accelerating net H⁺ elimination from cancer cells and across the interstitial space and (b) raise immune infiltration and inflammation in ErbB2/HER2-driven breast carcinomas, restricting tumor growth and improving patient survival.

Amplified Ca2+ dynamics and accelerated cell proliferation in breast cancer tissue during purinergic stimulation

Intracellular Ca²⁺ dynamics shape malignant behaviors of cancer cells. Whereas previous studies focused on cultured cancer cells, we here used breast organoids and colonic crypts freshly isolated from human and murine surgical biopsies. We performed fluorescence microscopy to evaluate intracellular Ca²⁺ concentrations in breast and colon cancer tissue with preferential focus on intracellular Ca²⁺ release in response to purinergic and cholinergic stimuli. Inhibition of the sarco‐/endoplasmic reticulum Ca²⁺ ATPase with cyclopiazonic acid elicited larger Ca²⁺ responses in breast cancer tissue, but not in colon cancer tissue, relative to respective normal tissue. The resting intracellular Ca²⁺ concentration was elevated, and ATP, UTP and acetylcholine induced strongly augmented intracellular Ca²⁺ responses in breast cancer tissue compared with normal breast tissue. In contrast, resting intracellular Ca²⁺ levels and acetylcholine‐induced increases in intracellular Ca²⁺ concentrations were unaffected and ATP‐ and UTP‐induced Ca²⁺ responses were smaller in colon cancer tissue compared with normal colon tissue. In accordance with the amplified Ca²⁺ responses, ATP and UTP substantially increased proliferative activity—evaluated by bromodeoxyuridine incorporation—in breast cancer tissue, whereas the effect was minimal in normal breast tissue. ATP caused cell death—identified with ethidium homodimer‐1 staining—in breast cancer tissue only at concentrations above the expected pathophysiological range. We conclude that intracellular Ca²⁺ responses are amplified in breast cancer tissue, but not in colon cancer tissue, and that nucleotide signaling stimulates breast cancer cell proliferation within the extracellular concentration range typical for solid cancer tissue.

Acid-base transporters and pH dynamics in human breast carcinomas predict proliferative activity, metastasis, and survival

Breast cancer heterogeneity in histology and molecular subtype influences metabolic and proliferative activity and hence the acid load on cancer cells. We hypothesized that acid-base transporters and intracellular pH (pH_i) dynamics contribute inter-individual variability in breast cancer aggressiveness and prognosis. We show that Na⁺,HCO₃^- cotransport and Na⁺/H⁺ exchange dominate cellular net acid extrusion in human breast carcinomas. Na⁺/H⁺ exchange elevates pH_i preferentially in estrogen receptor-negative breast carcinomas, whereas Na⁺,HCO₃^- cotransport raises pH_i more in invasive lobular than ductal breast carcinomas and in higher malignancy grade breast cancer. HER2-positive breast carcinomas have elevated protein expression of Na⁺/H⁺ exchanger NHE1/SLC9A1 and Na⁺,HCO₃^- cotransporter NBCn1/SLC4A7. Increased dependency on Na⁺,HCO₃^- cotransport associates with severe breast cancer: enlarged CO₂/HCO₃^--dependent rises in pH_i predict accelerated cell proliferation, whereas enhanced CO₂/HCO₃^--dependent net acid extrusion, elevated NBCn1 protein expression, and reduced NHE1 protein expression predict lymph node metastasis. Accordingly, we observe reduced survival for patients suffering from luminal A or basal-like/triple-negative breast cancer with high SLC4A7 and/or low SLC9A1 mRNA expression. We conclude that the molecular mechanisms of acid-base regulation depend on clinicopathological characteristics of breast cancer patients. NBCn1 expression and dependency on Na⁺,HCO₃^- cotransport for pH_i regulation, measured in biopsies of human primary breast carcinomas, independently predict proliferative activity, lymph node metastasis, and patient survival.

Dynamic Spectral Imaging Colposcopy Versus Regular Colposcopy in Women Referred With High-Grade Cytology: A Nonrandomized Prospective Study

OBJECTIVE

The aim of the study was to evaluate the sensitivity of dynamic spectral imaging (DSI) colposcopy compared with regular colposcopy for women referred with high-grade cervical cytology.

METHODS

In a prospective, nonrandomized, multicenter study, we included women referred for colposcopy at hospital gynecology clinics with high-grade cytology. Women were examined using either a regular or DSI colposcope. In both groups, colposcopists located 1 area viewed as most suspicious. In the DSI group, this was done before viewing the DSI map. Subsequently, an area was chosen based on the worst color of the DSI map, and further additional biopsies were taken. All women had 4 cervical biopsies taken, all analyzed separately. The main outcome was sensitivity to find cervical intraepithelial neoplasia grade 2 or worse (CIN2+).

RESULTS

A total of 261 women were examined using DSI colposcopy, and 156 women were examined using regular colposcopy. The sensitivity for finding CIN2+ when using the DSI technology as an adjunctive technology was found to be 82.2% (95% CI = 75.9-87.4), based on an average of 1.4 biopsies. This was corresponding in sensitivity to 2 biopsies taken using regular colposcopy (80.3%; 95% CI = 72.3-86.8). There was no difference in sensitivity for CIN+ between the groups when 3 or more biopsies were taken.

CONCLUSIONS

We found that the DSI colposcope may help direct biopsy placement; however, the improvement is based on small differences in needed biopsies and the clinical significance of this may be small. Multiple biopsies were still superior.

Management of low-grade cervical cytology in young women. Cohort study from Denmark

OBJECTIVE

Cytology findings of atypical squamous cells of unknown significance (ASCUS) or low-grade squamous intraepithelial lesion (LSIL) are common among women under 30, but evidence on best management strategy is insufficient. We therefore investigated how different management strategies used in Denmark influenced biopsy rates and detection of cervical intraepithelial neoplasia (CIN).

METHODS

Register-based cohort study including Danish women aged less than 30 years and born 1980-95, with ASCUS/LSIL as their first abnormal cervical cytology in 2008-16. Rates and relative risks (RR) of biopsy and detection of CIN3+, CIN2 and < CIN2 during two years follow-up were compared between women referred directly to colposcopy after ASCUS/LSIL or undergoing additional testing, including mRNA or DNA test for high risk HPV or repeat cytology.

RESULTS

19,946 women with ASCUS and 19,825 with LSIL were included in the study of whom 92% had adequate information about follow-up. Among women referred directly to biopsy, CIN3+ was detected among 21%, CIN2 in 17%, while 62% had < CIN2. Repeating cytology after 6 months reduced the biopsy rate to 44% of which 53% had < CIN2. Biopsy rates with HPV test were 67% for DNA test, 77% with 14-type mRNA test and 58% with 5-type mRNA test. The detection of CIN3+ was somewhat higher, between 13% and 14% for the three HPV tests vs. 11% with repeat cytology. However, the detection of < CIN2 (not indicating treatment) also increased with RR 2.11 (95% CI 2.01-2.21) for 14-type mRNA test, 1.35 (95% CI 1.29-1.41) for 5-type mRNA test, and 1.86 (95% CI 1.76-1.97) with HPV DNA test.

CONCLUSIONS

The choice of management strategy influences both the detection rate for severe lesions (CIN3+) and the proportion of women followed up for potentially insignificant findings.

Histological outcomes in HPV-screened elderly women in Denmark

Introduction

Danish women exit cervical cancer screening at age 65 years, but 23% of cervical cancer cases occur beyond this age. In addition, due to gradual implementation of cervical cancer screening, older women are underscreened by today´s standards. A one-time screening with HPV test was therefore offered to Danish women born before 1948.

Methods

Register based study reporting histology diagnoses and conizations in women found HPV positive in the one-time screening. Number and proportion of women with severe or non-severe histology results were calculated for screened and HPV-positive women by age group or region of residence. Number of women with biopsy and/or conization per case of cervical intraepithelial neoplasia (CIN) grade 2 or worse (CIN2+) or CIN3+ were also calculated by age groups and region.

Results

4,479 (4.1% of screened women) had positive HPV test. 94% of these had one or more additional tests. 2,785 (62%) of HPV-positive women had histology results, and conization was performed in 1,076 (24% of HPV-positive and 1% of all screened women). HPV positivity and CIN3+ detection varied little between regions, but the proportions of HPV positive women undergoing histology varied between regions from 40% to 86% and the proportion with conization from 13% to 36%. Correspondingly, the number of histologies and conizations per CIN3+ detected varied from 5.9 to 11.2 and 1.8 to 4.7, respectively. In total, 514 CIN2+ (0.47% of screened women, 11% of HPV-positive) and 337 CIN3+ (0.31% of screened women, 7.5% of HPV-positive) were diagnosed, including 37 cervical cancer cases.

Discussion

HPV screening of insufficiently screened birth cohorts can potentially prevent morbidity and mortality from cervical cancer but longer follow-up is needed to see if cancer incidence declines in the screened women in the coming years. Management strategies differed among regions which influenced the proportions undergoing biopsy/conization.

Can the dynamic spectral imaging (DSI) color map improve colposcopy examination for precancerous cervical lesions? A prospective evaluation of the DSI color map in a multi-biopsy clinical setting

Background

Colposcopy serves as a subjective examination of the cervix with low sensitivity to detect cervical intraepithelial dysplasia (CIN) grade 2 or worse (CIN2 +). Dynamic spectral imaging (DSI) colposcopy has been developed to provide an objective element to cervix examinations and has been proven to increase sensitivity of detecting CIN2 + . We aimed to assess the performance of the DSI color map and compared it to histological diagnoses of cervical biopsies in determining the CIN grade present.

Methods

Women were included in a consecutive, prospective manner at Randers Regional Hospital, Denmark. Women were eligible to participate if they were referred for colposcopy due to abnormal cervical smear (threshold:  ≥ ASCUS) or follow-up after previously diagnosed CIN. All women had four biopsies taken, one directed by colposcopists alone prior to viewing the DSI color map, one directed by the worst color on the respective DSI color map, and two additional biopsies. All biopsies were analyzed separately. We calculated sensitivity, specificity, positive predictive values, and negative predictive values (NPVs) with 95% confidence intervals (CIs).

Results

A total of 800 women were recruited. Of these, 529 (66.1%) were eligible for inclusion. The sensitivity of the DSI color map was found to be 48.1% (95% CI 41.1–55.1) in finding CIN grade 2 or worse (CIN2 +) when compared to the histological diagnosis of the DSI directed biopsy. This was 42.5% (95% CI 36.7–48.5) when compared to the final histological diagnosis of all four cervical biopsies and with an NPV of 53.5% (95% CI 50.5–56.5).

Conclusion

The worst color indicated by the DSI map might not consistently reflect the true grade of cervical dysplasia present. Thus, even though the DSI color map indicates low-grade changes, colposcopists should still consider taking biopsies from the area as high-grade changes might be present.

Trial registration: NCT04249856, January 31 2020 (retrospectively registered).

HrHPV testing vs liquid-based cytology in cervical cancer screening among women aged 50 and older: a prospective study

Introduction

Evidence supports high-risk human papilloma virus (HPV) testing as the primary cervical cancer screening tool. However, benefits and harms should be carefully considered before replacing liquid-based cytology. In women age 50 and older, we evaluated how a commercially available DNA amplification HPV test compares with routine liquid-based cytology.

Methods

This prospective study included 4043 patients who had a cervical sample analyzed from September 2011 to September 2012. Patients were followed between 64 and 76 months (median: 70 months). Samples were analyzed using both liquid-based cytology and the Cobas 4800 HPV DNA test. We calculated the diagnostic efficacy of liquid-based cytology and HPV, with or without the opposite test as triage, using cervical intraepithelial neoplasia (CIN2+/CIN3+) as reference.

Results

The patients had a median age of 58 years, (range; 50–90). At baseline, HPV prevalence was 8.0%: a total of 3.7% of patients had atypical squamous cells of undetermined significance or worse (ASCUS+). Positive test results were 1.9% for liquid-based cytology with HPV triage and 3.0% for HPV with liquid-based cytology triage. The cumulative incidence of CIN3+ was 1.0% (40/4043). Sensitivities for CIN3+ were: liquid-based cytology 47.5% (31.5%–63.9%); liquid-based cytology with HPV triage 45.0% (29.3%–61.5%); HPV 90.0% (76.3%–97.2%); and HPV with liquid-based cytology triage 67.5% (50.9%–81.4%). Corresponding specificities were: liquid-based cytology 96.6% (96.0%–97.2%); liquid-based cytology with HPV triage 98.5% (98.0%–98.8%); HPV 92.8% (92.0%–93.6%); and HPV with liquid-based cytology triage 97.7% (97.2%–98.1%). At baseline, HPV testing overlooked five cases of gynecological cancer other than cervical cancer. Five cervical cancers were detected, two had been overlooked at baseline by liquid-based cytology and two by HPV testing

Conclusion

HPV screening using DNA amplification is a promising alternative to liquid-based cytology in women age 50 and older, but evaluation of alternative triage methods is warranted. The risk of overlooking cancers needs consideration when replacing liquid-based cytology with HPV testing as a method for primary screening.

Prevalence of high-risk human papillomavirus after HPV-vaccination in Denmark

Vaccination against human papillomavirus (HPV) has been introduced as a public health initiative in many countries, including Denmark since October 2008. It is important to monitor postimplementation effectiveness of HPV‐vaccination at the population‐level. We studied HPV‐prevalence after first invitation to screening at age 23 years in women offered the quadrivalent HPV‐vaccine at the age of 14 years. Randomly selected screening samples from women born in 1994 in four out of five Danish regions were subjected to analysis for HPV in addition to routine cytology. Cobas4800 was used in all participating pathology departments. Data from a Danish prevaccination cross‐sectional study using Hybrid Capture 2, and a Danish split‐sample study using Cobas4800 were used for comparison. In the period from February 2017 to April 2019, 6233 screening samples from women born in 1994 were selected for HPV‐analysis; 27 samples had no HPV‐test and 3 samples had no HPV‐diagnosis, leaving 6203 samples with an HPV‐diagnosis. Prevalence of any high‐risk (HR) HPV was 35%; only 0.9% were positive for vaccine HPV types 16/18 while the remaining 34% were positive for other HR HPV. When comparing with prevaccination prevalence data, HPV‐16/18 decreased by 95%; RR = 0.05 (95% CI 0.04‐0.06), while other HR HPV remained fairly constant; RR = 0.88 (95% CI 0.82‐0.94) and RR = 0.95 (95% CI 0.88‐1.03), respectively. One‐third of women vaccinated as girls with the quadrivalent HPV‐vaccine were HR HPV‐positive at time of first invitation to screening. Vaccine HPV‐types 16 and 18 were almost eliminated, while the prevalence of nonvaccine HR HPV‐types remained constant.

What's new?

Vaccination against human papillomavirus (HPV) has been introduced as a public health initiative in many countries. However, data on HPV infection prevalence at screening age in HPV‐vaccinated birth cohorts remain scarce. This study found that HPV‐16 and 18 were almost eliminated in a population aged 23‐24 years where 92% of women received quadrivalent HPV vaccination at age 14. Prevalence of HPV 16 and 18 was lower in non‐vaccinated women than in previous birth cohorts not offered HPV‐vaccination. Nonetheless, one third of vaccinated women were positive for high‐risk HPV other than 16/18, with potential implications for cervical cancer prevention and screening programs.

Accuracy of colposcopy-directed biopsy vs dynamic spectral imaging directed biopsy in correctly identifying the grade of cervical dysplasia in women undergoing conization: A methodological study

INTRODUCTION

Dynamic spectral imaging (DSI) colposcopy has previously been found to improve sensitivity of CIN2+ detection. The aim of this study was to compare the histological diagnosis of colposcopic-directed biopsies (CDB) with that of DSI-directed biopsies in women undergoing conization, using the histological diagnosis of the conization specimen as gold standard.

MATERIAL AND METHODS

Women referred for colposcopy were included in a prospective cohort study at Randers Regional Hospital, Denmark, from January 2016 to February 2019. All women had four cervical punch biopsies taken. The first biopsy was taken from the area that appeared most abnormal by conventional colposcopy (ie, CDB) and the second biopsy from the area that appeared most abnormal using the DSI map. An additional two biopsies were taken either from other visible lesions or as random biopsies. Biopsies were analyzed separately. If any biopsies revealed cervical dysplasia of such a degree that excisional treatment was recommended, the patient was referred for conization. Subsequently, we compared the histological diagnosis of CDB and DSI-directed biopsies with that of the cone biopsy.

RESULTS

A total of 573 women were enrolled, 170 of which underwent conization. In women with an adequate colposcopy and representative biopsies (n = 124) there was an overall agreement rate between the worst biopsy diagnosis (of any four) and the conization diagnosis in 95.2% (95% CI 89.8-98.2) of women. CDB diagnosis agreed with the cone diagnosis in 80.6% (95% CI 72.6-87.2) of women. DSI-directed biopsy agreed with the cone diagnosis in 83.9% (95% CI 76.2-89.9) of women. The difference in detection rate between the CDB and the DSI-directed biopsy was, however, not significant (P = .54). Taking four biopsies increases the detection rate of cervical dysplasia to 95.2%, which was a significant increase from both CDB alone (P = .0008) and DSI-directed biopsy alone (P = .0053).

CONCLUSIONS

We found no significant difference in the ability to identify the cervical dysplasia grade between CDB and DSI-directed biopsies. A higher detection rate of cervical dysplasia was achieved with four biopsies than with one CDB biopsy or one DSI-directed biopsy.

Danish method study on cervical screening in women offered HPV vaccination as girls (Trial23): a study protocol

INTRODUCTION

The first birth cohorts of women offered human papillomavirus (HPV) vaccination as girls are now entering cervical screening. However, there is no international consensus on how to screen HPV vaccinated women. These women are better protected against cervical cancer and could therefore be offered less intensive screening. Primary HPV testing is more sensitive than cytology, allowing for a longer screening interval. The aim of Trial23 is to investigate if primary HPV testing with cytology triage of HPV positive samples is a reasonable screening scheme for women offered HPV vaccination as girls.

METHODS

Trial23 is a method study embedded in the existing cervical screening programme in four out of five Danish regions. Without affecting the screening programme, women born in 1994 are randomised to present screening with liquid-based cytology every third year (present programme arm) or present screening plus an HPV test (HPV arm). The study started 1 February 2017 and will run over three screening rounds corresponding to 7-8 years.

ANALYSES

The primary endpoint is cervical intraepithelial neoplasia grade 3 or above. The trial is undertaken as a non-inferiority study including intention-to-treat and per-protocol analyses. The potential effect of primary HPV screening with a 6-year interval will be calculated from the observed data.

ETHICS AND DISSEMINATION

The study protocol has been submitted to the ethical committee and deemed a method study. All women are screened according to routine guidelines. The study will contribute new evidence on the future screening of HPV vaccinated birth cohorts of women. All results will be published in open-access journal.

TRIAL REGISTRATION

NCT03049553; Pre-results.

Cervical screening in Denmark - a success followed by stagnation

INTRODUCTION

Despite an intensive screening activity, the incidence of cervical cancer in Denmark has remained stable for the last 15 years, while regional differences have increased. To search for explanations, we investigated possible weaknesses in the screening program.

MATERIAL AND METHODS

Data on the screen-targeted women were retrieved from Statistics Denmark. Data on screening activity were retrieved from the annual reports from 2009 to 2015 on quality of cervical screening. Coverage was calculated as proportion of screen-targeted women with at least one cytology sample within recommended time intervals. Insufficient follow-up was calculated as proportion of abnormal and unsatisfactory samples not followed up within recommended time intervals. Diagnostic distribution was calculated for samples with a satisfactory cytology diagnosis.

RESULTS

Coverage remained stable at 75%-76% during the study period. Annually, approximately 100,000 women are screened before they are eligible for invitation, and 600,000 invitations and reminders are issued resulting in screening of 200,000 women. In 2009, 21% of abnormal and unsatisfactory samples were not followed up within the recommended time interval; a proportion that had decreased to 15% in 2015. Overall, 11% of satisfactory samples with a cytology diagnosis were abnormal, but with surprising variation from 6% to 15% across regions.

DISCUSSION

The success of a screening program depends first of all on coverage and timely follow-up of abnormal findings. Our analysis indicated that the currently high incidence of cervical cancer in Denmark may partly be due to low screening coverage. Also worrisome is a high proportion of non-timely follow-up of abnormal findings. Innovative ways to improve coverage and follow-up are urgently needed.

Abstract P5-05-03: Upregulated purinergic signaling enhances cell proliferation in human and murine breast carcinomas

The composition of the extracellular tumor microenvironment differs from that of most other tissues and is thought to provide cancer cells with a growth and survival advantage compared to normal cells. In solid tumors, the extracellular concentration of ATP can be elevated to ~100 µm and extracellular pH can be as low as 6.5. In the current project, we investigate the consequences of purinergic signaling in human and murine breast carcinomas: we study intracellular Ca2+ signals and associated changes in cell proliferation during stimulation with extracellular nucleotides.

We employ biopsies of human and murine primary breast carcinomas and compare them with matched normal breast tissue. Human biopsies are obtained with written informed consent from patients undergoing breast conserving surgery at Aarhus University Hospital or Regional Hospital Randers in Denmark. Murine biopsies are from mice overexpressing unactivated ErbB2 specifically in the breast tissue. We isolate epithelial organoids (~150 µm diameter) from tissue biopsies by partial digestion with collagenase III. Organoids loaded with the Ca2+-sensitive fluorophore Fura-2 are studied by fluorescence microscopy. In separate experiments, cell proliferation is quantified by detecting newly synthesized DNA using immunofluorescence imaging of organoids incubated with the thymidine analogue bromodeoxyuridine (BrdU).

We find that intracellular Ca2+ responses during stimulation with extracellular ATP are elevated 2- to 10-fold in breast carcinomas from mice and humans, respectively, compared to matched normal breast tissue. We observe similar differences between breast cancer tissue and normal breast tissue in response to stimulation with the P2Y2/P2Y4-agonist UTP, whereas virtually no rise in the intracellular concentration of Ca2+ is observed in response to the P2X7-agonist 3'-O-(4-benzoyl)benzoyl-ATP. Application of cyclopiazonic acid – an inhibitor of the sarcoplasmic/endoplasmic reticulum Ca2+-ATPase – also cause exaggerated intracellular Ca2+ responses in breast cancer compared to normal breast tissue. Consistent with the elevated Ca2+ responses, stimulation with 100 µm ATP or 100 µm UTP increases the rate of cell proliferation (i.e., fraction of BrdU-positive cells) by ~2-fold in the breast cancer tissue.

In conclusion, we find that purinergic signaling is upregulated in human and murine breast carcinomas compared to normal breast tissue. Activation of purinergic receptors – most likely P2Y2 and/or P2Y4 – enhances cell proliferation in breast cancer tissue. We propose that the high ATP levels in the tumor microenvironment promote breast cancer development or progression and that the associated signaling pathways represent promising targets for therapy.

Citation Format: Mele M, McWhan K, Henningsen M, Vahl P, Jensen V, Johansen T, Pedersen H, Christiansen P, Bødtkjer E. Upregulated purinergic signaling enhances cell proliferation in human and murine breast carcinomas [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P5-05-03.

Insulin degludec does not increase antibody formation versus insulin glargine: an evaluation of phase IIIa trials

We examined insulin antibody formation in patients with type 1 (T1D) or type 2 diabetes (T2D) treated with once-daily insulin degludec (IDeg) or insulin glargine (IGlar) to evaluate the impact of antibody formation on efficacy and safety. Insulin antibodies were measured using subtraction radioimmunoassays in six phase IIIa clinical trials using IDeg (n = 2250) and IGlar (n = 1184). Spearman's correlation coefficient was used to evaluate associations between cross-reacting antibodies and change from baseline glycated haemoglobin (HbA1c) and insulin dose. IDeg- and IGlar-specific antibodies remained low [<1% bound/total radioactivity (B/T)] and with low levels of antibodies cross-reacting with human insulin in patients with T1D (<20% B/T) and T2D (<6% B/T). Spearman's correlation coefficients between insulin antibody levels and change in HbA1c or insulin dose were low in both treatment groups. No clinically meaningful differences in adverse event (AE) rates were observed in patients with >10% B/T or without an absolute increase in antibodies cross-reacting with human insulin. IDeg treatment resulted in few immunogenic responses in patients with T1D and T2D; antibody formation was not associated with change in HbA1c, insulin dose or rates of AEs.

Improved health status with insulin degludec compared with insulin glargine in people with type 1 diabetes

AIMS

The efficacy and safety of insulin degludec (degludec), a new-generation ultra-long-acting basal insulin, was compared with insulin glargine (glargine) in people with Type 1 diabetes mellitus in a 16-week, open-label, randomized trial. Health status, an important aspect of effective diabetes management, was also assessed.

METHODS

Degludec (n = 59) or glargine (n = 59) were injected once daily, with insulin aspart at mealtimes. Health status assessment utilized the validated Short Form 36 Health Survey, version 2, which has two summary component scores for mental and physical well-being, each comprising four domains.

RESULTS

At study end, HbA(1c) reductions were comparable between groups, but confirmed nocturnal hypoglycaemia was significantly less frequent with degludec [relative rate 0.42 (95% CI 0.25-0.69)], and overall hypoglycaemia numerically less frequent [relative rate 0.72 (95% CI 0.52-1.00)]. After 16 weeks, a significant improvement in Short Form 36 Health Survey mental component score of +3.01 (95% CI 0.32-5.70) was obtained for degludec against glargine, attributable to significant differences in the social functioning [+8.04 (95% CI 1.89-14.18)] and mental health domains [+2.46 (95% CI 0.10-4.82)]. For mental component score, Cohen's effect size was 0.42, indicating a small-to-medium clinically meaningful difference. The physical component score [+0.66 (95% CI -2.30 to 3.62)] and remaining domains were not significantly different between degludec and glargine.

CONCLUSIONS

In the context of comparable overall glycaemic control with glargine, degludec improved mental well-being as measured using the mental component score of the Short Form 36 Health Survey. The improvements in overall mental component score and the underlying social functioning and mental health domains with degludec compared with glargine may relate to the observed reduction in hypoglycaemic events.

Design and performance of the collective Thomson scattering receiver at ASDEX Upgrade

Here we present the design of the fast-ion collective Thomson scattering receiver for millimeter wave radiation installed at ASDEX Upgrade, a tokamak for fusion plasma experiments. The receiver can detect spectral power densities of a few eV against the electron cyclotron emission background on the order of 100 eV under presence of gyrotron stray radiation that is several orders of magnitude stronger than the signal to be detected. The receiver down converts the frequencies of scattered radiation (100-110 GHz) to intermediate frequencies (IF) (4.5-14.5 GHz) by heterodyning. The IF signal is divided into 50 IF channels tightly spaced in frequency space. The channels are terminated by square-law detector diodes that convert the signal power into DC voltages. We present measurements of the transmission characteristics and performance of the main receiver components operating at mm-wave frequencies (notch, bandpass, and lowpass filters, a voltage-controlled variable attenuator, and an isolator), the down-converter unit, and the IF components (amplifiers, bandpass filters, and detector diodes). Furthermore, we determine the performance of the receiver as a unit through spectral response measurements and find reasonable agreement with the expectation based on the individual component measurements.

Genetic diversity within and among Atlantic cod (Gadus morhua) farmed in marine cages: a proof-of-concept study for the identification of escapees

This study presents a molecular genetic characterization of Atlantic cod reared in commercial marine farms. Samples consisted of approximately 47 fish collected from nine cages located on four farms throughout Norway. In addition, 28 farmed escapees were recaptured in the sea (443 fish in total). Nine microsatellite loci and the Pan I gene were analysed, revealing a total of 181 alleles. Each sample contained 43–63% of total allelic variation. Comparing variation with published data for wild cod indicates that lower genetic variation exists within single cages than in wild populations. Significant linkage disequilibrium was observed amongst pairs of loci in all samples, suggesting a low number of contributing parental fish. Global F_ST was 0.049, and the highest pairwise F_ST value (pooled loci) was 0.085. For single loci, the Pan I gene was the most diagnostic, displaying a global F_ST of 0.203. Simulations amongst the samples collected on farms revealed an overall correct self-assignment percentage of 75%, demonstrating a high probability of identifying individuals to their farm of origin. Identification of the 28 escapees revealed a single cage as the most likely source of origin for half of the escapees, whilst the remaining fish were assigned to a mixture of samples, suggesting more than one source of escapees.

Broadband notch filter design for millimeter-wave plasma diagnostics

Notch filters are integrated in plasma diagnostic systems to protect millimeter-wave receivers from intensive stray radiation. Here we present a design of a notch filter with a center frequency of 140 GHz, a rejection bandwidth of ∼900 MHz, and a typical insertion loss below 2 dB in the passband of ±9 GHz. The design is based on a fundamental rectangular waveguide with eight cylindrical cavities coupled by T-junction apertures formed as thin slits. Parameters that affect the notch performance such as physical lengths and conductor materials are discussed. The excited resonance mode in the cylindrical cavities is the fundamental TE(11). The performance of the constructed filter is measured using a vector network analyzer monitoring a total bandwidth of 30 GHz. We compare the measurements with numerical simulations.

Eosinophilic/T-cell chorionic vasculitis and intrauterine fetal demise at 34 weeks: case report and review of the literature

Eosinophilic/T-cell chorionic vasculitis is a rare form of chorionic vasculitis. A multifocal form of eosinophilic/T-cell chorionic vasculitis is presented involving chorionic vessels radiating away from the amniotic fluid, without associated chorioamnionitis. There was, however, an associated fetal demise.

Sodium homeostasis in lymphocytes and blood pressure alterations before and during salt restriction in normotensives and in essential hypertensives

Blood pressure, lymphocytic sodium content and sodium efflux were studied in hypertensive and normotensive subjects during salt restriction. Diastolic blood pressure decreased significantly in both groups. In essential hypertension the initial high lymphocyte sodium content decreased during salt depletion with a simultaneous decrease in absolute sodium efflux probably due to primary changes in sodium influx. Conversely intralymphocytic sodium content increased in normotensive subjects, which may be caused by an inhibition of the sodium, potassium pump. Our findings indicate that autoregulatory mechanisms with regard to lymphocyte sodium metabolism differs between hypertensive and normotensive subjects.

Rubidium uptake of mononuclear leukocytes from normotensive and borderline hypertensive first degree relatives to patients with essential hypertension

Uptake of 86Rubidium of mononuclear leukocytes (MNL) was used as a measure of cellular sodium-potassium pump activity. 86Rb-uptake was determined with the pump stimulated mainly from inside the cells by sodium as well as with a combined stimulation from inside by sodium and from outside by Rb. In the first case there was an increased pump activity in MNL from borderline hypertensive offspring of hypertensive patients (BHO), and this may be related to an increased number of pump sites observed previously (10). Estimation of maximal pump activity (Vmax) of MNL suggested that Vmax of each pump site in MNL from BHO may be decreased compared to control value of MNL from healthy normotensive subjects.

Effect of oral salt loading on blood pressure and lymphocyte sodium metabolism in borderline hypertension

A randomized double-blind cross-over trial was performed to test the effects of oral salt loading (normal diet + 200 mmol NaCl/day for 4 weeks followed by normal diet + 400 mmol/day for 1 week) against placebo on blood pressure and lymphocyte sodium homeostasis in 10 young borderline hypertensive men, genetically predisposed for essential hypertension. Salt loading caused no significant changes in blood pressure levels, lymphocyte sodium content and efflux. In conclusion, our subjects seem insensitive to a few weeks of excessive salt intake.

Reduction of adiposity with prolonged growth hormone treatment in old obese rats: effects on glucose handling and early insulin signaling

OBJECTIVES

Growth Hormone (GH) promotes loss of body fat and causes insulin resistance. It is debated whether reduction of body fat mass during long term growth hormone (GH) administration improves carbohydrate metabolism. To answer this question we assessed carbohydrate handling and tissue specific function of the insulin receptor (IR) and insulin receptor substrate-1 (IRS-1) during prolonged GH treatment of obese rats.

METHODS

Body fat % estimated by DEXA scanning, plasma IGF-I, glucose and insulin were studied in 17 months old dietary induced obese rats treated for 4, 21 or 41 days (GH: 4 mg/kg/d or saline total n=90). Adipose tissue, muscle and liver samples were obtained after 21 days and expression and tyrosine phosphorylation of IR and IRS-1 proteins and the degree of IRS-1-Janus Kinase-2 (JAK2) interaction were analyzed by immunoprecipitation and immunoblotting.

RESULTS

Forty-one days GH treatment caused the body fat to decline significantly to 20+/-3% (Mean+/-SEM), whereas it remained steady on 51+/-4% in the pair fed group. Insulin levels in response to OGTT were significantly elevated throughout the experiment. IR amount was elevated in adipose tissue but decreased in liver after GH treatment while IR phosphorylation was increased in muscle only. IRS-1 amount was elevated in adipose tissue and muscle while IRS-1 phosphorylation was increased only in liver. The association of IRS-1 with JAK-2 was increased in liver and muscle.

CONCLUSIONS

An extensive reduction of fat mass did not improved signs of insulin resistance in GH treated old obese rats. The molecular events associated with GH treatment included tissue specific changes in the function of IR and IRS-1 suggesting the liver to be the primary site of insulin resistance. Furthermore, the association of IRS-1with JAK-2 in the course of GH signaling could present a mechanism for GH to directly induce insulin resistance.

Growth hormone-mediated breakdown of body fat: insulin and leptin responses to GH are modulated by diet composition and caloric intake in old rats

This work was performed to elucidate whether growth hormone (GH)-mediated loss of adipose tissue and responses in plasma insulin and leptin are modulated by diet composition. 12-month-old rats were first fed a high-fat (HF) diet or a low-fat (LF) diet for 14 weeks. After that, GH or saline was administered to rat groups that were maintained on either HF or LF diets or that were switched from the HF to the LF diet. All 6 groups had free access to food. One additional saline group was pair-fed with the GH group that was switched from the HF to the LF diet. The caloric consumption of this latter group was also translated to yet another GH group receiving restricted amounts of the HF diet. GH was given in a total dose of 4 mg/kg/d for three weeks. After sacrifice, blood was collected and tissues were excised. In groups injected with saline, the weight of excised adipose tissue was 60 +/- 4.7, 41 +/- 3.8 and 50 +/- 4.5 g in animals that continued with the HF diet, LF diet, or that were switched from HF to LF, respectively. Corresponding figures after GH treatment were significantly (p < 0.05) decreased to 38 +/- 2.7, 30 +/- 2.3, and 31 +/- 2.7 g, respectively. Pair-feeding had no effect, whereas only 26 +/- 3.0 g of adipose tissue was retrieved in rats fed restricted amounts of HF diet while receiving GH. In this group, plasma insulin and leptin were also significantly (p < 0.05) depressed compared with other GH groups, especially to the group fed the unrestricted HF diet (203 +/- 35 vs. 1345 +/- 160 pmol/l and 9.3 +/- 1.2 vs. 31 +/- 4.4 micro g/l). In conclusion, this study shows that GH mediates breakdown of adipose tissue under a variety of dietary conditions, and that induction of hyperinsulinemia can be prevented if GH treatment is combined with restricted feeding of a diet which is relatively low in carbohydrates and rich in fat. This will also promote a fall of plasma leptin.

Growth hormone-mediated breakdown of body fat: effects of GH on lipases in adipose tissue and skeletal muscle of old rats fed different diets

Lipid storage and breakdown is mainly controlled by lipoprotein lipase and hormone-sensitive lipase. The aim of this work was to elucidate whether growth hormone mediated loss of adipose tissue involves a concerted action on tissue lipases, and to what degree such events are modulated by dietary regimen. Twelve-month-old rats fed first a high-fat diet or a low-fat diet for 14 weeks were injected with saline or growth hormone (4 mg/kg/d) for four days or three weeks in different combinations with either high- or low-fat diets. In adipose tissue, growth hormone generally inhibited lipoprotein lipase and also attenuated the inhibiting effect of insulin on hormone-sensitive lipase activity. Growth hormone treatment combined with restricted high-fat feeding reduced the activity of both lipases in adipose tissue and stimulated hormone-sensitive lipase in muscle. Generally, plasma levels of free fatty acids, glycerol and cholesterol were reduced by growth hormone, and in combination with restricted high-fat feeding, triglyceride levels improved too. We conclude that growth hormone inhibits lipid storage in adipose tissue by reducing both lipoprotein lipase activity and insulin's inhibitory action on hormone-sensitive lipase. We also propose that growth hormone's effects on tissue lipases and blood lipids are modulated by dietary regimen.

The cystic fibrosis transmembrane conductance regulator is not a base transporter in isolated duodenal epithelial cells

Duodenal epithelial bicarbonate secretion has previously been shown to be greatly impaired in mice deficient of the cystic fibrosis transmembrane conductance regulator (CFTR). It has been proposed that transmembranal bicarbonate transport occurs through the CFTR channel itself. In the present study, the transport of acid/base equivalents across the plasma membrane of proximal duodenal epithelial cells from CFTR deficient mice was compared with that of cells from normal littermates. Mixed epithelial cells from both villi and crypts were isolated from proximal duodenum and intracellular pH was assessed by cuvette-based fluorescence spectrometry using the pH sensitive dye 2',7'-bis-(2-carboxyethyl)-5-(and-6)-carboxyfluorescein. The steady state intracellular pH, the acid extrusion rate and the alkaline extrusion rate were unaffected by CFTR deficiency in the presence of CO(2)/HCO(-)(3). Forskolin had no effect on acid extrusion or alkaline extrusion rates. In control experiments without CO(2)/HCO(-)(3), the intrinsic buffering capacities, the steady state intracellular pH and the acid extrusion rates were equivalent in the cells from CFTR deficient mice and normal littermates. The results are consistent with a model where acid/base transport is almost exclusively mediated by the previously described transporters in the murine duodenum (i.e. Na+/H+ exchange, Cl(-)/HCO(-)(3). exchange and Na+:HCO(-)(3). cotransport). There were no evidence for significant CFTR dependent HCO(-)(3). transport in proximal duodenal epithelial cells of mixed villus and crypt origin.

Nuclear import and export signals enable rapid nucleocytoplasmic shuttling of the atypical protein kinase C lambda

The atypical protein kinase C (PKC) isoenzymes, lambda/iota- and zetaPKC, play important roles in cellular signaling pathways regulating proliferation, differentiation, and cell survival. By using green fluorescent protein (GFP) fusion proteins, we found that wild-type lambdaPKC localized predominantly to the cytoplasm, whereas both a kinase-defective mutant and an activation loop mutant accumulated in the nucleus. We have mapped a functional nuclear localization signal (NLS) to the N-terminal part of the zinc finger domain of lambdaPKC. Leptomycin B treatment induced rapid nuclear accumulation of GFP-lambda as well as endogenous lambdaPKC suggesting the existence of a CRM1-dependent nuclear export signal (NES). Consequently, we identified a functional leucine-rich NES in the linker region between the zinc finger and the catalytic domain of lambdaPKC. The presence of both the NLS and NES enables a continuous shuttling of lambdaPKC between the cytoplasm and nucleus. Our results suggest that the exposure of the NLS in both lambda- and zetaPKC is regulated by intramolecular interactions between the N-terminal part, including the pseudosubstrate sequence, and the catalytic domain. Thus, either deletion of the N-terminal region, including the pseudosubstrate sequence, or a point mutation in this sequence leads to nuclear accumulation of lambdaPKC. The ability of the two atypical PKC isoforms to enter the nucleus in HeLa cells upon leptomycin B treatment differs substantially. Although lambdaPKC is able to enter the nucleus very rapidly, zetaPKC is much less efficiently imported into the nucleus. This difference can be explained by the different relative strengths of the NLS and NES in lambdaPKC compared with zetaPKC.

The obese Göttingen minipig as a model of the metabolic syndrome: dietary effects on obesity, insulin sensitivity, and growth hormone profile

The objective of the study reported here was to induce obesity in the female Göttingen minipig to establish a model of the human metabolic syndrome. Nine- to ten-month-old female Göttingen minipigs received a high-fat high-energy (HFE) diet or a low-fat, low-energy (LFE) diet. The energy contents derived from fat were 55 and 13 %, respectively. After 5 weeks, animals were subjected to dual energy x-ray absorptiometry (DEXA) scanning, intravenous glucose tolerance testing (IVGTT), and 6-h growth hormone profile recording. After treatment, mean body weight of pigs of the LFE group was 21.0 +/- 0.4 kg, and was 26.8 +/- 0.2 kg in pigs of the HFE group (P < 0.0001). The DEXA scanning indicated that the fat content of the LFE group was 10.0 +/- 1.2 % versus 15.2 +/- 0.7 % in the HFE group (P < 0.003). Triglycerides concentration was significantly (P < 0.05) increased in pigs of the HFE group (0.24 +/- 0.03 mM), compared with that in pigs of the LFE group (0.13 +/- 0.04 mM). Preprandial plasma glucose and insulin concentrations were not affected, but insulin area under the curve during IVGTT was significantly high in the obese animals. Growth hormone (GH) secretion was low in both groups of pigs. The obese minipig shares some of the metabolic impairments seen in obese humans, and may thus serve as a model of the metabolic syndrome.

Molecular and functional evidence for electrogenic and electroneutral Na(+)-HCO(3)(-) cotransporters in murine duodenum

Inward Na(+)-HCO(3)(-) cotransport has previously been demonstrated in acidified duodenal epithelial cells, but the identity and localization of the mRNAs and proteins involved have not been determined. The molecular expression and localization of Na(+)-HCO(3)(-) cotransporters (NBCs) were studied by RT-PCR, sequence analysis, and immunohistochemistry. By fluorescence spectroscopy, the intracellular pH (pH(i)) was recorded in suspensions of isolated murine duodenal epithelial cells loaded with 2',7'-bis(2-carboxyethyl)-5(6)-carboxyfluorescein. Proximal duodenal epithelial cells expressed mRNA encoding two electrogenic NBC1 isoforms and the electroneutral NBCn1. Both NBC1 and NBCn1 were localized to the basolateral membrane of proximal duodenal villus cells, whereas the crypt cells did not label with the anti-NBC antibodies. DIDS or removal of extracellular Cl(-) increased pH(i), whereas an acidification was observed on removal of Na(+) or both Na(+) and Cl(-). The effects of inhibitors and ionic dependence of acid/base transporters were consistent with both inward and outward Na(+)-HCO(3)(-) cotransport. Hence, we propose that NBCs are involved in both basolateral electroneutral HCO(3)(-) transport as well as basolateral electrogenic HCO(3)(-) transport in proximal duodenal villus cells.

Superactivation of Pax6-mediated transactivation from paired domain-binding sites by dna-independent recruitment of different homeodomain proteins

The Pax6 genes encode evolutionary conserved transcription factors that act high up in the regulatory hierarchy controlling development of central organs such as the eyes and the central nervous system. These proteins contain two DNA-binding domains. The N-terminal paired domain is separated from a paired-type homeodomain by a linker region, and a transactivation domain is located C-terminal to the homeodomain. Vertebrate Pax6 genes express a paired-less isoform of Pax6 (Pax6DeltaPD) from an internal start codon in the coding region between the paired domain and homeodomain. We now provide evidence for an interaction between the full-length isoform and Pax6DeltaPD, which enhances the transactivation activity of Pax6 from paired domain-binding sites. The paired-like homeodomain protein Rax behaved similarly to Pax6DeltaPD. Both Pax6DeltaPD and Rax bound to the homeodomain of Pax6 in vitro in the absence of specific DNA binding. Coimmunoprecipitation experiments following cotransfection confirmed the existence of complexes between Pax6 and Pax6DeltaPD, Pax6 and Rax, and Pax6DeltaPD and Rax in vivo. Interestingly, the C-terminal subdomain of the paired domain and the homeodomain can interact with each other. The paired domain can also interact with itself. Surprisingly, GST pull-down assays revealed that the homeodomains of such diverse proteins as Chx10, Six3, Lhx2, En-1, Prep1, Prox1, and HoxB1 could all bind to Pax6, and several of these enhanced Pax6-mediated transactivation upon coexpression. Since many homeodomain proteins are coexpressed with Pax6 in several tissues during development, our results indicate the existence of novel regulatory interactions that may be important for fine tuning of gene regulation.

The nuclear factor SPBP contains different functional domains and stimulates the activity of various transcriptional activators

SPBP (stromelysin-1 platelet-derived growth factor-responsive element binding protein) was originally cloned from a cDNA expression library by virtue of its ability to bind to a platelet-derived growth factor-responsive element in the human stromelysin-1 promoter. A 937-amino acid-long protein was deduced from a 3995-nucleotide murine cDNA sequence. By analyses of both human and murine cDNAs, we now show that SPBP is twice as large as originally found. The human SPBP gene contains six exons and is located on chromosome 22q13.1-13.3. Two isoforms differing in their C termini are expressed due to alternative splicing. PCR analyses of multitissue cDNA panels showed that SPBP is expressed in most tissues except for ovary and prostate. Functional mapping revealed that SPBP is a nuclear, multidomain protein containing an N-terminal region with transactivating ability, a novel type of DNA-binding domain containing an AT hook motif, and a bipartite nuclear localization signal as well as a C-terminal zinc finger domain. This type of zinc finger domain is also found in the trithorax family of chromatin-based transcriptional regulator proteins. Using cotransfection experiments, we find that SPBP enhances the transcriptional activity of various transcription factors such as c-Jun, Ets1, Sp1, and Pax6. Hence, SPBP seems to act as a transcriptional coactivator.

The effect of long-term streptozotocin-induced diabetes on contractile and relaxation responses of coronary arteries: selective attenuation of CGRP-induced relaxations

1. This study investigates the effect of partially metabolic controlled long-term (34 weeks) streptozotocin (STZ)-induced diabetes on relaxation and contractile responses of isolated coronary arteries to seven different vasoactive agents. 2. The average fasting and non-fasting blood glucose concentrations (mM) were significantly elevated in STZ-induced diabetic rats (P<0.0001; 10.4+/-0.4 and 16. 6+/-1.1, n=15) compared to those (4.3+/-0.03 and 4.7+/-0.18, n=11) in age-matched controls. The level of glycated haemoglobin (HbA(1)) was also significantly (P<0.0001) increased in STZ-induced diabetic rats. In STZ-induced diabetic rats, the HbA(1) levels were significantly correlated with the non-fasting blood glucose concentrations (r=0.76; P=0.003; n=13). In both groups, there was no significant correlation between the HbA(1) levels and maximal responses or sensitivities to the vasoactive agents. 3. The maximal relaxation induced by rat-alphacalcitonin gene-related peptide (rat-alphaCGRP) was significantly attenuated in the coronary arteries of STZ-induced diabetic rats (P<0.05; 40+/-7%, n=15) compared to that in age-matched controls (63+/-3%, n=11). However, there was no significant difference in the sensitivity to rat-alphaCGRP between the two groups. 4. There was no significant difference in either maximal response or sensitivity to any of the six other vasoactive agents between STZ- induced diabetic rats (n=15) and age-matched controls (n=11). 5. Our results show that partially metabolic controlled long-term (34 weeks) STZ-induced diabetes causes a selective depression of rat-alphaCGRP-induced relaxation in the intramural coronary arteries of Wistar rats.

NHE1, NHE2, and NHE3 contribute to regulation of intracellular pH in murine duodenal epithelial cells

Na(+)/H(+)-exchangers (NHE) mediate acid extrusion from duodenal epithelial cells, but the isoforms involved have not previously been determined. Thus we investigated 1) the contribution of Na(+)-dependent processes to acid extrusion, 2) sensitivity to Na(+)/H(+) exchange inhibitors, and 3) molecular expression of NHE isoforms. By fluorescence spectroscopy the recovery of intracellular pH (pH(i)) was measured on suspensions of isolated acidified murine duodenal epithelial cells loaded with 2', 7'-bis(2-carboxyethyl)-5(6)-carboxyfluorescein. Expression of NHE isoforms was studied by RT-PCR and Western blot analysis. Reduction of extracellular Na(+) concentration ([Na(+)](o)) during pH(i) recovery decreased H(+) efflux to minimally 12.5% of control with a relatively high apparent Michaelis constant for extracellular Na(+). The Na(+)/H(+) exchange inhibitors ethylisopropylamiloride and amiloride inhibited H(+) efflux maximally by 57 and 80%, respectively. NHE1, NHE2, and NHE3 were expressed at the mRNA level (RT-PCR) as well as at the protein level (Western blot analysis). On the basis of the effects of low [Na(+)](o) and inhibitors we propose that acid extrusion in duodenal epithelial cells involves Na(+)/H(+) exchange by isoforms NHE1, NHE2, and NHE3.

Distribution of bacterial growth activity in flow-chamber biofilms

In microbial communities such as those found in biofilms, individual organisms most often display heterogeneous behavior with respect to their metabolic activity, growth status, gene expression pattern, etc. In that context, a novel reporter system for monitoring of cellular growth activity has been designed. It comprises a transposon cassette carrying fusions between the growth rate-regulated Escherichia coli rrnBP1 promoter and different variant gfp genes. It is shown that the P1 promoter is regulated in the same way in E. coli and Pseudomonas putida, making it useful for monitoring of growth activity in organisms outside the group of enteric bacteria. Construction of fusions to genes encoding unstable Gfp proteins opened up the possibility of the monitoring of rates of rRNA synthesis and, in this way, allowing on-line determination of the distribution of growth activity in a complex community. With the use of these reporter tools, it is demonstrated that individual cells of a toluene-degrading P. putida strain growing in a benzyl alcohol-supplemented biofilm have different levels of growth activity which develop as the biofilm gets older. Cells that eventually grow very slowly or not at all may be stimulated to restart growth if provided with a more easily metabolizable carbon source. Thus, the dynamics of biofilm growth activity has been tracked to the level of individual cells, cell clusters, and microcolonies.

The role of growth hormone and glucocorticoid in glucose handling in vivo

Growth hormone (GH) can oppose the catabolic effects of glucocorticoids. However, both hormones have adverse effects on carbohydrate metabolism. Here we examined the interactive effects of GH and the glucocorticoid methylprednisolone (MP) on glucose tolerance, insulin resistance and [3H]2,6-deoxyglucose uptake of peripheral tissues in rats. Female Wistar rats received either saline, GH (2.7 mg/kg), MP (5.0 mg/kg) or GH+MP. After 7 days treatment, animals were subjected to an i.v. glucose tolerance test. In a second experiment, animals treated as above were anesthetized and injected with human insulin (0.5 U/kg), [3H]2,6-deoxyglucose (500 microCi/kg), and [14C]mannitol (25 microCi/kg), to estimate insulin resistance and [3H]2,6-deoxyglucose uptake in fat and muscle. Weight gain in controls was 7.6+/-1.7 g, while GH treatment increased the mean body weight by 18.7+/-2.2 g (P<0.0002) and MP inhibited weight gain down to 0.0+/-1.0 g (P<0.004). This drop in weight gain was reversed back to normal when GH was given in combination with MP. After a glucose tolerance test no significant differences in glucose area under the curve were detected when comparing individual groups with the control group, but samples taken just before this test revealed that basal insulin was significantly elevated in the group treated with GH (174+/-27 pM, P<0.008), or GH+MP (209+/-21 pM, P<0.004), when compared with controls (107+/-17 pM). MP alone had no effect (122+/-19, P<0.3). After an i.v. bolus of insulin the group receiving GH+MP had a significantly (P<0.007) higher level of circulating glucose compared with controls (6.5+/-0.3 mM vs 4.4+/-0.7 mM). Despite this, there were no differences in peripheral glucose uptake between the two groups. In conclusion this study shows that a combined administration of GH and MP decreases the potency by which insulin decreases circulating glucose levels, but that peripheral tissues are not primarily involved in this insulin resistance.

Phosphorylation of the transactivation domain of Pax6 by extracellular signal-regulated kinase and p38 mitogen-activated protein kinase

The transcription factor Pax6 is required for normal development of the central nervous system, the eyes, nose, and pancreas. Here we show that the transactivation domain (TAD) of zebrafish Pax6 is phosphorylated in vitro by the mitogen-activated protein kinases (MAPKs) extracellular-signal regulated kinase (ERK) and p38 kinase but not by Jun N-terminal kinase (JNK). Three of four putative proline-dependent kinase phosphorylation sites are phosphorylated in vitro. Of these sites, the serine 413 (Ser413) is evolutionary conserved from sea urchin to man. Ser413 is also phosphorylated in vivo upon activation of ERK or p38 kinase. Substitution of Ser413 with alanine strongly decreased the transactivation potential of the Pax6 TAD whereas substitution with glutamate increased the transactivation. Reporter gene assays with wild-type and mutant Pax6 revealed that transactivation by the full-length Pax6 protein from paired domain-binding sites was strongly enhanced (16-fold) following co-transfection with activated p38 kinase. This enhancement was largely dependent on the Ser413 site. ERK activation, however, produced a 3-fold increase in transactivation which was partly independent of the Ser413 site. These findings provide a starting point for further studies aimed at elucidating a post-translational regulation of Pax6 following activation of MAPK signaling pathways.