Diagnosing Pathologic Complete Response in the Breast After Neoadjuvant Systemic Treatment of Breast Cancer Patients by Minimal Invasive Biopsy: Oral Presentation at the San Antonio Breast Cancer Symposium on Friday, December 13, 2019, Program Number GS5-03

OBJECTIVE

We evaluated the ability of minimally invasive, image-guided vacuum-assisted biopsy (VAB) to reliably diagnose a pathologic complete response in the breast (pCR-B).

SUMMARY BACKGROUND DATA

Neoadjuvant systemic treatment (NST) elicits a pathologic complete response in up to 80% of women with breast cancer. In such cases, breast surgery, the gold standard for confirming pCR-B, may be considered overtreatment.

METHODS

This multicenter, prospective trial enrolled 452 women presenting with initial stage 1-3 breast cancer of all biological subtypes. Fifty-four women dropped out; 398 were included in the full analysis. All participants had an imaging-confirmed partial or complete response to NST and underwent study-specific image-guided VAB before guideline-adherent breast surgery. The primary endpoint was the false-negative rate (FNR) of VAB-confirmed pCR-B.

RESULTS

Image-guided VAB alone did not detect surgically confirmed residual tumor in 37 of 208 women [FNR, 17.8%; 95% confidence interval (CI), 12.8-23.7%]. Of these 37 women, 12 (32.4%) had residual DCIS only, 20 (54.1%) had minimal residual tumor (<5 mm), and 19 of 25 (76.0%) exhibited invasive cancer cellularity of ≤10%. In 19 of the 37 cases (51.4%), the false-negative result was potentially avoidable. Exploratory analysis showed that performing VAB with the largest needle by volume (7-gauge) resulted in no false-negative results and that combining imaging and image-guided VAB into a single diagnostic test lowered the FNR to 6.2% (95% CI, 3.4%-10.5%).

CONCLUSIONS

Image-guided VAB missed residual disease more often than expected. Refinements in procedure and patient selection seem possible and necessary before omitting breast surgery.

Review of guidance papers on regression modeling in statistical series of medical journals

Although regression models play a central role in the analysis of medical research projects, there still exist many misconceptions on various aspects of modeling leading to faulty analyses. Indeed, the rapidly developing statistical methodology and its recent advances in regression modeling do not seem to be adequately reflected in many medical publications. This problem of knowledge transfer from statistical research to application was identified by some medical journals, which have published series of statistical tutorials and (shorter) papers mainly addressing medical researchers. The aim of this review was to assess the current level of knowledge with regard to regression modeling contained in such statistical papers. We searched for target series by a request to international statistical experts. We identified 23 series including 57 topic-relevant articles. Within each article, two independent raters analyzed the content by investigating 44 predefined aspects on regression modeling. We assessed to what extent the aspects were explained and if examples, software advices, and recommendations for or against specific methods were given. Most series (21/23) included at least one article on multivariable regression. Logistic regression was the most frequently described regression type (19/23), followed by linear regression (18/23), Cox regression and survival models (12/23) and Poisson regression (3/23). Most general aspects on regression modeling, e.g. model assumptions, reporting and interpretation of regression results, were covered. We did not find many misconceptions or misleading recommendations, but we identified relevant gaps, in particular with respect to addressing nonlinear effects of continuous predictors, model specification and variable selection. Specific recommendations on software were rarely given. Statistical guidance should be developed for nonlinear effects, model specification and variable selection to better support medical researchers who perform or interpret regression analyses.

Vacuum-Assisted Breast Biopsy After Neoadjuvant Systemic Treatment for Reliable Exclusion of Residual Cancer in Breast Cancer Patients

Background

About 40 % of women with breast cancer achieve a pathologic complete response in the breast after neoadjuvant systemic treatment (NST). To identify these women, vacuum-assisted biopsy (VAB) was evaluated to facilitate risk-adaptive surgery. In confirmatory trials, the rates of missed residual cancer [false-negative rates (FNRs)] were unacceptably high (> 10%). This analysis aimed to improve the ability of VAB to exclude residual cancer in the breast reliably by identifying key characteristics of false-negative cases.

Methods

Uni- and multivariable logistic regressions were performed using data of a prospective multicenter trial (n = 398) to identify patient and VAB characteristics associated with false-negative cases (no residual cancer in the VAB but in the surgical specimen). Based on these findings FNR was exploratively re-calculated.

Results

In the multivariable analysis, a false-negative VAB result was significantly associated with accompanying ductal carcinoma in situ (DCIS) in the initial diagnostic biopsy [odds ratio (OR), 3.94; p < 0.001], multicentric disease on imaging before NST (OR, 2.74; p = 0.066), and age (OR, 1.03; p = 0.034). Exclusion of women with DCIS or multicentric disease (n = 114) and classication of VABs that did not remove the clip marker as uncertain representative VABs decreased the FNR to 2.9% (3/104).

Conclusion

For patients without accompanying DCIS or multicentric disease, performing a distinct representative VAB (i.e., removing a well-placed clip marker) after NST suggests that VAB might reliably exclude residual cancer in the breast without surgery. This evidence will inform the design of future trials evaluating risk-adaptive surgery for exceptional responders to NST.

Role of oxytocin in modulating addictive behaviour

Background

The brain oxytocin system is involved in a wide range of addictive behaviors, inhibiting prime- and cue-induced relapse in preclinical models of substance use disorders. Animal studies linked oxytocin’s effects on drug ingestion to modulation of neurotransmission in the nucleus accumbens (NAc). We set out to investigate whether oxytocin can modulate alcohol cue-induced functional connectivity between the brain reward system and cortical regions.

Methods

Fifteen male heavy social drinkers were enrolled in a randomized double-blind placebo-controlled cross-over functional magnetic resonance imaging study (fMRI) investigating the effect of 24 IU oxytocin on alcohol cue-modulated functional connectivity.

Results

Results of the functional connectivity analyses show that oxytocin application significantly reduced connectivity between the NAc and cuneus and thalamo-occipital connectivity, while enhancing connectivity between the paracingulate gyrus and precentral gyrus (tow-sided seed-level false discovery rate p_FDR < 0.05). These effects were specific to the alcohol presentation and were absent during processing of neutral pictures. In addition, the NAc-cuneus connectivity significantly correlated with subjective alcohol cue-induced craving during the scanning session (r = 0.538, p = 0.024). Conclusion: Results provide initial evidence for condition-specific and significant attenuation of NAc connectivity by oxytocin in a sample of heavy social drinkers that was related to lower subjective alcohol craving during the fMRI task. Oxytocin-induced attenuation of NAc connectivity was specific to processing alcohol stimuli and might reflect an attenuation of alcohol-cue saliency by oxytocin that could lead to a reduction of the sensitivity towards the appetitive aspects of alcohol cues.

Disclosure

No significant relationships.

Systematic review of education and practical guidance on regression modeling for medical researchers who lack a strong statistical background: Study protocol

In the last decades, statistical methodology has developed rapidly, in particular in the field of regression modeling. Multivariable regression models are applied in almost all medical research projects. Therefore, the potential impact of statistical misconceptions within this field can be enormous Indeed, the current theoretical statistical knowledge is not always adequately transferred to the current practice in medical statistics. Some medical journals have identified this problem and published isolated statistical articles and even whole series thereof. In this systematic review, we aim to assess the current level of education on regression modeling that is provided to medical researchers via series of statistical articles published in medical journals. The present manuscript is a protocol for a systematic review that aims to assess which aspects of regression modeling are covered by statistical series published in medical journals that intend to train and guide applied medical researchers with limited statistical knowledge. Statistical paper series cannot easily be summarized and identified by common keywords in an electronic search engine like Scopus. We therefore identified series by a systematic request to statistical experts who are part or related to the STRATOS Initiative (STRengthening Analytical Thinking for Observational Studies). Within each identified article, two raters will independently check the content of the articles with respect to a predefined list of key aspects related to regression modeling. The content analysis of the topic-relevant articles will be performed using a predefined report form to assess the content as objectively as possible. Any disputes will be resolved by a third reviewer. Summary analyses will identify potential methodological gaps and misconceptions that may have an important impact on the quality of analyses in medical research. This review will thus provide a basis for future guidance papers and tutorials in the field of regression modeling which will enable medical researchers 1) to interpret publications in a correct way, 2) to perform basic statistical analyses in a correct way and 3) to identify situations when the help of a statistical expert is required.

Spatio-temporal distribution of spinetail devil ray Mobula mobular in the eastern tropical Atlantic Ocean

The distribution of the spinetail devil ray Mobula mobular in the eastern tropical Atlantic remains poorly known compared to the Pacific and Indian Oceans. We used fishery-dependent data and generalized additive models to examine the environmental characteristics associated with the presence of M. mobular in the eastern Atlantic Ocean. Results revealed that the distribution of M. mobular is significantly associated with seasonal upwelling systems in coastal and pelagic areas. Our model predicted the presence of the species in areas where there is evidence of its occurrence, such as the Angolan upwelling system and the coast of Ghana. In addition, our model predicted new hotspot areas, including locations around the Mauritanian upwelling system, the Guinea coast, offshore Ghana and the south coast of Angola and Brazil, where sample sizes are limited. Those areas, as well as the environmental preferences depicted by the model, provide valuable information about the habitat and ecology of the spinetail devil ray. Future research lines derived from this study, as well as its limitations, are discussed. Furthermore, in light of our results we discuss the improvements that are needed to contribute to the conservation and management of this vulnerable species.

The renin-angiotensin-aldosterone system blockade and arterial stiffness in renal transplant recipients - a cross-sectional prospective observational clinical study

INTRODUCTION

Arterial stiffness parameters can be used as a predictor of cardiovascular events in the general population and renal transplant recipients (RTRs). Additionally, the renin-angiotensin-aldosterone-system (RAAS) blockade mitigates arterial stiffness in the general population. There are no sufficient data concerning the role of the RAAS blockade in reducing arterial stiffness among patients after kidney transplantation. The aim of this study is to assess the influence of the above blockade on arterial stiffness in RTRs.

METHODS

344 stable RTRs were enrolled in the study. 204 (59.3%) of them received RAAS blockers (angiotensin convertase inhibitors - ACEIs or angiotensin receptor blockers - ARBs): group RAAS (+), and 140 (40.7%) were not treated with such agents: group RAAS (-).

RESULTS

In the RAAS (+) group, 55.9% of the patients used ARBs and 44.1% ACEIs. Cardiovascular disease (coronary artery disease and/or peripheral obliterans artery disease) (27.9% vs 14.3%, p<0.05), and heart failure (27.4% vs 24.3%, p<0.05) were significantly more often diagnosed in the RAAS (+) group when compared to the RAAS (-) group. Systolic blood pressure, diastolic blood pressure and all arterial stiffness parameters (baPWV, cfPWV, pulse pressure) did not differ significantly between the RAAS (+) and RAAS (-) groups. The results revealed that cardiovascular disease in patients was associated with a significant increase in both, the PWV and pulse pressure. No difference between the arterial stiffness parameters was observed in patients with a cardiovascular disease, diabetes and heart failure in the RAAS (+) and RAAS (-) groups. Moreover, beta-blockers and diuretics ameliorated the arterial stiffness parameters.

CONCLUSIONS

This study showed the indication bias of the RAAS prescription, and no conclusion on the influence of RAAS on arterial stiffness can be drawn. The results indicated diuretics and beta-blockers as agents lowering the arterial stiffness in RTRs.

Oil gland and oil pores in billfishes: in search of a function

Billfishes are well known for their distinctive elongated rostra, i.e. bills. The functional significance of billfish rostra has been frequently discussed and the recent discovery of an oil gland (glandula oleofera) at the base of the rostrum in swordfish, Xiphias gladius, has added an interesting facet to this discussion regarding the potential co-evolution of gland and rostra. Here, we investigated the oil gland and oil pores (through which the oil is brought to the skin surface) of four billfish species - swordfish, Atlantic blue marlin (Makaira nigricans), Indo-Pacific sailfish (Istiophorus platypterus) and striped marlin (Kajikia audax) - and provide detailed evidence for the presence of an oil gland in the last three. All four species had a high density of oil pores on the forehead which is consistent with the hypothesis of hydrodynamic benefits of the oil. The extension of the pores onto the front half of the rostrum in sailfish and striped marlin, but not in swordfish or blue marlin, suggests that the oil may have additional functions. One such function could be linked to the antibacterial and anti-inflammatory properties of the oil. However, the available evidence on predatory rostrum use (and hence the likelihood of tissue damage) is only partly consistent with the extension of pores on rostra across species. We conclude that the oil gland probably serves multiple, non-mutually exclusive functions. More detailed information on rostrum use in blue marlin and swordfish is needed to better link behavioural and morphological data with the aim of accomplishing a full comparative analysis.

Influence of lipid profile and statin administration on arterial stiffness in renal transplant recipients

Background

Hyperlipidemia is one of the major risk factors for developing a cardiovascular disease (CVD) and it is a frequent post-transplant complication, occurring in up to 60% of the renal transplant recipients (RTRs). Lipid lowering therapy with HMG-CoA reductase inhibitors (statins) is generally recommended and may reduce the overall cardiovascular risk. The aim of this study was to evaluate the lipid profile, statin administration and their relationship with arterial stiffness parameters in RTRs.

Methods

Three hundred and forty-four stable RTRs (62.5% male) transplanted between 1994 and 2018 were randomly enrolled to the study. The following parameters of arterial stiffness was measured in each patient: ankle brachial index, carotid femoral pulse wave velocity (baPWV left and right, cfPWV) and pulse pressure (PP right and left). The study group was divided based on the use statins: 143 (41.6%) and 201 (58.4%). RTRs were qualified to the statin (+) and the statin (−) group, respectively.

Results

In the statin (+) as compared to statin (−) group there were more patients with a CVD (32.9% vs. 14.9%) and diabetes (25.2% vs. 14.4%). In the whole study group, CVD was associated with a significant increase of both baPWV and cfPWV as well as PP (8.5 mmHg). There were significant differences in arterial stiffness parameters (baPWV, cfPWV, PP) between the statin (+) and the statin (−) group.

Conclusions

Arterial stiffness was increased in RTRs with CVD and hyperlipidemia. The control of hyperlipidemia was poor in RTRs.

Linking hunting weaponry to attack strategies in sailfish and striped marlin

Linking morphological differences in foraging adaptations to prey choice and feeding strategies has provided major evolutionary insights across taxa. Here, we combine behavioural and morphological approaches to explore and compare the role of the rostrum (bill) and micro-teeth in the feeding behaviour of sailfish (Istiophorus platypterus) and striped marlin (Kajikia audax) when attacking schooling sardine prey. Behavioural results from high-speed videos showed that sailfish and striped marlin both regularly made rostrum contact with prey but displayed distinct strategies. Marlin used high-speed dashes, breaking schools apart, often contacting prey incidentally or tapping at isolated prey with their rostra; while sailfish used their rostra more frequently and tended to use a slower, less disruptive approach with more horizontal rostral slashes on cohesive prey schools. Capture success per attack was similar between species, but striped marlin had higher capture rates per minute. The rostra of both species are covered with micro-teeth, and micro-CT imaging showed that species did not differ in average micro-tooth length, but sailfish had a higher density of micro-teeth on the dorsal and ventral sides of their rostra and a higher amount of micro-teeth regrowth, suggesting a greater amount of rostrum use is associated with more investment in micro-teeth. Our analysis shows that the rostra of billfish are used in distinct ways and we discuss our results in the broader context of relationships between morphological and behavioural feeding adaptations across species.

Injury-mediated decrease in locomotor performance increases predation risk in schooling fish

The costs and benefits of group living often depend on the spatial position of individuals within groups and the ability of individuals to occupy preferred positions. For example, models of predation events for moving prey groups predict higher mortality risk for individuals at the periphery and front of groups. We investigated these predictions in sardine (Sardinella aurita) schools under attack from group hunting sailfish (Istiophorus platypterus) in the open ocean. Sailfish approached sardine schools about equally often from the front and rear, but prior to attack there was a chasing period in which sardines attempted to swim away from the predator. Consequently, all sailfish attacks were directed at the rear and peripheral positions of the school, resulting in higher predation risk for individuals at these positions. During attacks, sailfish slash at sardines with their bill causing prey injury including scale removal and tissue damage. Sardines injured in previous attacks were more often found in the rear half of the school than in the front half. Moreover, injured fish had lower tail-beat frequencies and lagged behind uninjured fish. Injuries inflicted by sailfish bills may, therefore, hinder prey swimming speed and drive spatial sorting in prey schools through passive self-assortment. We found only partial support for the theoretical predictions from current predator-prey models, highlighting the importance of incorporating more realistic predator-prey dynamics into these models.This article is part of the themed issue 'Physiological determinants of social behaviour in animals'.

Accidental mechanical asphyxia of children in Germany between 2000 and 2008

Accidents constitute one of the greatest risks to children, yet there are few medical reports that discuss the subject of accidental asphyxia. However, a systematic analysis of all documented cases in Germany over the years 2000-2008 has now been conducted, aiming at identifying patterns of accidental asphyxia, deducing findings, defining avoidance measures and recommending ways of increasing product safety and taking possible precautions. The analysis is based on a detailed retrospective analysis of all 91 relevant autopsy reports from 24 different German forensic institutes. A variety of demographic and morphological data was systematically collected and analysed. In 84 of the 91 cases, the sex of the victim was reported, resulting in a total of 57 boys (68 %) and 27 girls (32 %). The age spread ranged between 1 day and 14 years, with an average of 5.9 years. Most accidents occurred in the first year of life (20 %) or between the ages of 1 and 2 years (13 %). In 46 % of cases, the cause of death was strangulation, with the majority occurring in the home environment. In 31 % of all cases, the cause of death was positional asphyxia, the majority resulting from chest compression. In 23 % of cases, the cause of death was aspiration, mainly of foreign bodies. Today, accidental asphyxiation is a rare cause of death in children in Germany. Nevertheless, the majority of cases could have been avoided. Future incidence can be reduced by implementing two major precautions: increasing product safety and educating parents of potentially fatal risks. Specific recommendations relate to children's beds, toys and food.

Food-cue evoked activation of reward pathways is modulated by the satiety factor leptin: An fMRI study in obese and normal weight subjects

Introduction

Mechanisms contributing to the development and maintenance of obesity remain to be elucidated especially regarding the interaction between appetite regulating hormones and mesolimbic reward circuits. Leptin was recently suggested to attenuate dopamine release in mesolimbic reward pathways. We now test the functional relevance assessing whether leptin plasma concentration affects the BOLD-response following the presentation of food cues.

Methods

21 obese and 23 normal weight subjects were investigated. Visual food cues and neutral stimuli were presented in a block design during fMRI. Blood-samples were collected immediately prior to the scan to assess plasma leptin concentration. Using linear regression analyses, the association between BOLD response to food cues and the body mass index (BMI) as well as plasma leptin concentration was examined.

Results

Food-cues elicited activation of large cortical and subcortical networks, whereas only in obese patients food cues activated the left ventral and right dorsal striatum. Mean plasma concentration of leptin was significantly increased in obese subjects compared to normal weight controls. We found a significant positive correlation between the food cue-induced BOLD signal change in the ventral striatum and leptin plasma concentration. Furthermore, ventral and dorsal striatum BOLD response to food cues was significantly positive associated with the body mass index (BMI).

Conclusions

These findings suggest a physiological role of the satiety factor leptin in modulating responsivity of reward pathways towards food cues. Altered homeostatic feedback regulation of the mesolimbic brain reward circuit might explain the inability of obese patients to adapt their food intake according to physiologically needs.

[Non-adjustable sling for treatment of male stress urinary incontinence]

Even though the artificial sphincter is still the treatment of choice in the surgical therapy of male stress urinary incontinence, recent developments have introduced numerous minimally invasive treatment options with acceptable clinical results. The male slings have been included into the EAU guidelines for treatment of male stress urinary incontinence. A distinct choice of patients and treatment options will lead to the highest chance of success. Besides the adjustable compressive slings, the non-adjustable and non-compressive AdVance Sling offers a possible option for a functional approach to treatmentratio. A critical assessment of all these methods remains essential and prospective randomized trials are still missing.

[Retroperitoneal extravasation as the primary symptom of a pancreatic carcinoma]

Adenocarcinoma of the pancreas has a low 5-year survival rate of approximately 5%. Early diagnostics of pancreatic carcinoma during early tumor stages is made difficult by the lack of symptoms. In particular, individuals suffering from carcinomas located within the pancreatic tail are at high risk of a missed diagnosis. The early symptoms are usually nonspecific (e.g., nonspecific upper abdominal complaints, decrease in weight, loss of appetite, and impaired performance) and are characteristic only in carcinomas of the pancreatic head with painless icterus. If the patient complains of low back pain, a severe infiltration with no chance of a complete surgical resection is found in most cases. An adenocarcinoma of the pancreatic tail was diagnosed in this case report based on a large retroperitoneal extravasation missing further symptoms. The extravasation found represented a primary infiltration of the left ureter which was not diagnosed in primary computed tomography.

[Secondary right-sided diaphragmatic hernia following neonatal group B Streptococcal septicaemia in a preterm infant]

We report on a case of a secondary right-sided diaphragmatic hernia following group B streptococcal (GBS) septicaemia in a very low birth weight infant born at 30 weeks. After initial improvement, the diagnosis of a secondary right-sided diaphragmatic hernia was suspected with the persistent radiological pulmonary right-sided image on the chest x-ray and the clinical degradation. The diagnosis was confirmed by ultrasonography on day 43. The postoperative course was simple. Persistent respiratory distress in a neonate, after a GBS septicaemia associated with a right pulmonary opacity on the chest x-ray, should prompt a careful evaluation. A secondary right-sided diaphragmatic hernia should be considered. Treatment is surgery, the prognosis is good in the absence of pulmonary hypoplasia.

Evaluation of different protocols for gene transfer into non-obese diabetes/severe combined immunodeficiency disease mouse repopulating cells

PURPOSE

Although gene transfer with retroviral vectors has shown distinct clinical success in defined settings, efficient genetic manipulation of hematopoietic progenitor cells remains a challenge. To address this issue we have evaluated different transduction protocols and retroviral constructs in the non-obese diabetes (NOD)/severe combined immunodeficiency disease (SCID) xenograft model.

METHODS

An extended transduction protocol requiring 144 h of in vitro manipulation was compared to a more conventional protocol requiring 96 h only.

RESULT

While pretransplantation analysis of cells transduced with a retroviral vector, expressing the enhanced green fluorescent protein (EGFP) marker gene, demonstrated significantly higher overall transduction rates for the extended protocol (33.6 +/- 2.3 vs. 22.1 +/- 3.8%), EGFP expression in CD34+ cells before transplantation (4.0 +/- 0.9 vs. 11.6 +/- 2.5%), engraftment of human cells in NOD/SCID bone marrow 4 weeks after transplantation (4.5 +/- 1.7 vs. 36.5 +/- 9.4%) and EGFP expression in these cells (0 +/- 0 vs. 11.3 +/- 2.8%) were significantly impaired. When the 96 h protocol was used in combination with the spleen focus forming virus (SFFV)/murine embryonic stem cell (MESV) hybrid vector SFbeta11-EGFP, high transduction rates for CD45+ (41.0 +/- 5.3%) and CD34+ (38.5 +/- 3.7%) cells prior to transplantation, as well as efficient human cell engraftment in NOD/SCID mice 4 weeks after transplantation (32.4 +/- 3.5%), was detected. Transgene expression was observed in B-lymphoid (15.9 +/- 2.0%), myeloid (36.5 +/- 3.5%) and CD34+ cells (10.1 +/- 1.5%).

CONCLUSION

Our data show that CD34+ cells maintained in cytokines for multiple days may differentiate and loose their capacity to contribute to the haematological reconstitution of NOD/SCID mice. In addition, the SFFV/MESV hybrid vector SFbeta11-EGFP allows efficient transduction of and gene expression in haematopoietic progenitor cells.

[Survival and pattern of failure in palliative endobronchial HDR -- brachytherapy using iridium 192 in recurring bronchial carcinoma]

To evaluate the impact of palliative high dose rate brachytherapy on survival and a pattern of failure, we performed a matched pair study. 94 patients with tumor recurrence after external beam radiation received endobronchial brachytherapy. They were followed prospectively and matched retrospectively with 94 comparable patients who had not received brachytherapy. Matched parameters were age, gender, smoking behaviour, histology, tumor stage, EBRT-dose and fractionation. The leading cause of death in both groups was generalized tumor growth. In the combined therapy group, fatal hemorrage was 27.7 %, two and a half times higher than in the EBRT group with 10.6 %, whereas respiratory insufficiency in the brachytherapy group was 6.4 % and 11.7 % in the EBRT group. A complete remission after brachytherapy yielded a 10.5 months longer mean survival. Patients dying from fatal hemorrhage after endobronchial brachytherapy lived on average 10.2 months longer than matched EBRT patients dying from the same cause. Analyzing the time-course of fatal hemorrage in the brachytherapy group we conclude that - because of its early onset in the first 10 months after induction of therapy roughly 20 % of the deaths can be attributed to a radiation damage. In those patients who died after 10 months the major cause of fatal hemorrhage was the natural course of sqamous cell carcinoma with prolonged survival.

[Waterborne outbreak of gastroenteritis transmitted through the public water supply]

INTRODUCTION

The chlorination of public water supplies has led researchers to largely discard drinking water as a potential source of gastroenteritis outbreaks. The aim of this study was to investigate an outbreak of waterborne disease associated with drinking water from public supplies.

METHODS

A historical cohort study was carried out following notification of a gastroenteritis outbreak in Baqueira (Valle de Arán, Spain). We used systematic sampling to select 87 individuals staying at hotels and 67 staying in apartments in the target area. Information was gathered on four factors (consumption of water from the public water supply, sandwiches, water and food in the ski resorts) as well as on symptoms. We assessed residual chlorine in drinking water, analyzed samples of drinking water, and studied stool cultures from 4 patients. The risk associated with each water source and food type was assessed by means of relative risk (RR) and 95% confidence intervals (CI).

RESULTS

The overall attack rate was 51.0% (76/149). The main symptoms were diarrhea 87.5%, abdominal pain 80.0%, nausea 50.7%, vomiting 30.3%, and fever 27.0%. The only factor associated with a statistically significant risk of disease was consumption of drinking water (RR = 11.0; 95% CI, 1.6-74.7). No residual chlorine was detected in the drinking water, which was judged acceptable. A problem associated with the location of the chlorinator was observed and corrected. We also recommended an increase in chlorine levels, which was followed by a reduction in the number of cases. The results of stool cultures of the four patients were negative for enterobacteria.

CONCLUSIONS

This study highlights the potential importance of waterborne outbreaks of gastroenteritis transmitted through drinking water considered acceptable and suggests the need to improve microbiological research into these outbreaks (viruses and protozoa detection).

Cytokine profiles in peripheral blood mononuclear cells and lymph node cells from piglets infected in utero with porcine reproductive and respiratory syndrome virus

The aim of the present study was to investigate at 2, 4, and 6 weeks after birth cytokine expression by peripheral blood mononuclear cells and bronchial lymph node cells from piglets infected in utero with porcine reproductive and respiratory syndrome virus (PRRSV). Technically, by flow cytometry we were able to measure gamma interferon (gamma-IFN), tumor necrosis factor alpha (TNF-alpha), interleukin-4 (IL-4), and IL-8 levels. In general, we found increases in the percentages of IL-4-, gamma-IFN-, and TNF-alpha-producing lymphocytes in the infected piglets compared to the percentages in the uninfected control animals, while there was a decrease in the percentage of IL-8-producing monocytes. We believe that these findings reflect a general lymphocyte activation stage that is created due to the infection and that occurs in combination with impairment of the monocyte function, possibly due to the ongoing viral replication in these cells. Single-cell bronchial lymph node preparations exhibited very much the same cytokine profiles as peripheral blood mononuclear cells except for a lack of IL-8 production. When the levels of the individual cytokines in the three groups of PRRSV-infected piglets were compared, the levels of cytokine expression at 4 weeks diverged from those at 2 and 6 weeks, in that there was a significant decrease in the numbers of lymphocytes producing gamma-IFN and TNF-alpha. This tendency was also observed among blood monocytes and lymph node macrophages. Possible reasons for this temporary immunosuppression in the piglets at 4 weeks are discussed.

Type and position of promoter elements in retroviral vectors have substantial effects on the expression level of an enhanced green fluorescent protein reporter gene

PURPOSE

Although gene transfer with retroviral vectors has already been applied to patients as part of clinical protocols, low expression of transgenes in target cells still remains a problem. Therefore, we compared various retroviral vectors using different promoters and backbones for expression of the enhanced green fluorescent protein (EGFP) reporter gene in fibroblasts and CD34+ cells.

METHODS

The N2A retroviral vector was used to test expression from the herpes simplex virus thymidine kinase promoter (vector N2A-TK-EGFP), a human phosphoglycerate kinase promoter (vector N2A-PGK-EGFP), and the SV40 promoter (vector N2A-SV-EGFP). Additional constructs used the spleen focus-forming virus (SFFV) long terminal repeat (LTR) as promoter and expressed EGFP alone (vector SFbeta1-EGFP) or EGFP and a downstream (vector SFbeta1-EGFP-IRES) or upstream (vector SFbeta1-IRES-EGFP) internal ribosomal entry site.

RESULTS

For NIH 3T3 cells the fluorescence-activated cell sorting analysis revealed that the most active internal promoter was the SV40 promoter in the vector N2A-SV-EGFP (mean fluorescence intensity, MFI, 66.7 +/- 0.4), followed by N2A-PGK-EGFP (26.3 +/- 1.8 MFI), and N2A-TK-EGFP (4.8 +/- 0.1 MFI). Expression from the SFbeta1-EGFP vector (82.6 +/- 6.7 MFI) and the SFbeta1-EGFP-IRES vector (102.8 +/- 6.2 MFI) was higher than from SFbeta1-IRES-EGFP vector (15.5 +/- 1.8 MFI). In human CD34-positive cells, the EGFP expression from all vectors was considerably lower than in fibroblasts with the SFbeta1-EGFP vector still being four- to fivefold more active than the internal promoters tested.

CONCLUSION

The SFFV LTR seems to allow a high expression of transgenes, as long as the transgene is not expressed downstream of an internal ribosomal entry site. Internal promoters may be useful for targeted gene expression in specific cell types, but the reduced level of expression from some internal promoters has to be taken into consideration.

[Minimally invasive surgery in persistent pneumothorax and pneumocystis carinii infection]

The most frequent pulmological complication of AIDS is pneumocystis carinii pneumonia (PCP), which in 2% of cases will cause a spontaneous pneumothorax. Every AIDS patient who develops a pneumothorax is highly suspicious for a pneumocystis carinii pneumonia too. We describe the case of an AIDS patient who suffered from pneumothorax caused by PCP. Conventional tube thoracostomy with continuous suction and tetracycline pleurodesis were unsuccessful. The patient recovered however after resection of PCP cysts in the apical upper lobe and talcum pleurodesis by means of minimally invasive surgery.

Changes in rabbit corneal epithelial membrane permeability caused by locally applied Pseudomonas aeruginosa cytotoxin: a microfluorometric examination in vivo

The effects of a pore-forming protein from Pseudomonas aeruginosa on the rabbit cornea were tested in vivo by measuring intraepithelial carboxyfluorescein accumulation. Carboxyfluorescein diacetate and subsequently the P. aeruginosa cytotoxin were applied by means of contact lenses with a spherical cavity on the concave surface. This allowed the application of defined concentrations of carboxyfluorescein diacetate and cytotoxin on a defined area of the corneal epithelium. Starting at 0.5 microM, cytotoxin increased the epithelial cell membrane permeability for the intracellular carboxyfluorescein within 1 min. At higher concentrations cells were shed from the epithelium. Corresponding morphological changes of the cellular structure of the corneal epithelium were observed and documented by fluorescence photomicrography. The healing process of toxified corneal epithelium appeared to be complete within 3 days. The data presented here indicate the possible role of cytotoxin-induced changes in epithelial permeability in P. aeruginosa infections. In this context, the role of soft contact lenses as a possible cytotoxin reservoir is discussed.

Ultrasonic evaluation of bladder neck position and mobility: the influence of urethral catheter, bladder volume, and body position

The influence of urethral catheter, bladder volume, and body position on the ultrasonic assessment of bladder neck position and mobility was evaluated in 24 incontinent women. The bladder neck position was described by two independent parameters: BS-distance, from the bladder neck to the lower tip of the symphysis pubis, and the rotation angle between the BS-line and the symphyseal middline. Catheterisation resulted in apposition of the bladder neck towards the symphysis pubis, seen as a significant shortening of the BS-distance in postmenopausal women without estrogen replacement. The rotation angle was unaffected. Increasing the bladder volume to symptomatically full resulted in increased capacity to withhold, since the rotation angle decreased 6.6 degrees. Examination in the sitting position, compared to the supine resulted in bladder neck descent to a "lower level," and the rotation angle increased in average 16 degrees. Bladder neck mobility was unaffected by catheterisation and body position. Vaginal ultrasonic evaluation of bladder neck suspension is recommended to be performed without a catheter, with a comfortably full bladder in a convenient, but standardised examination position.

Application of nuclear analytical techniques using long-life sealed-tube neutron generators

The new range of sealed-tube neutron generators developed by SODERN appears to be appropriate for the industrial environment. The main characteristics are the high emission stability during the very long lifetime of the tube, flexible pulsed mode capability, safety in operation with no radiation in "off" state, and the easy transportation of equipment. Some applications of the neutron generators, called GENIE, are considered: high-sensitivity measurement of transuranic elements in nuclear waste drums, bulk material analysis for process control, and determination of the airborne pollutants for environmental monitoring.

A comparison of electrophysiologically guided antiarrhythmic drug therapy with beta-blocker therapy in patients with symptomatic, sustained ventricular tachyarrhythmias

BACKGROUND

Antiarrhythmic drug therapy guided by invasive electrophysiologic testing is now widely used in patients with symptomatic, sustained ventricular tachyarrhythmias.

METHODS

We conducted a prospective, randomized trial in 170 patients to investigate whether this approach would improve long-term outcome. Patients whose arrhythmia was inducible by programmed electrical stimulation were assigned to treatment with electrophysiologically guided drug therapy based on serial testing (61 patients) or with metoprolol (54 patients). Electrophysiologically guided therapy consisted of serial testing of antiarrhythmic agents to identify the first one that rendered the arrhythmia noninducible. The 55 patients whose arrhythmia was noninducible during the initial electrophysiologic test were also treated with metoprolol.

RESULTS

During a mean (+/- SD) follow-up period of 23 +/- 17 months, recurrent, nonfatal arrhythmia occurred in 44 patients and sudden death due to cardiac factors in 27. The incidence of symptomatic arrhythmia and sudden death combined was virtually the same in the two groups with inducible arrhythmia after two years of observation (electrophysiologically guided therapy vs. metoprolol therapy, 46 percent vs. 48 percent). The outcome was more favorable in the patients with noninducible arrhythmia at base line (75 percent had neither adverse event) than in those with inducible arrhythmia who were assigned to metoprolol therapy (P = 0.009 by log-rank test). Only 6 of the 29 patients (21 percent) with inducible arrhythmia that became noninducible during drug therapy had recurrent arrhythmia or sudden death, as compared with 21 of the 32 patients (66 percent) with arrhythmia that continued to be inducible (P less than 0.001). A multivariate regression analysis identified continued inducibility of the arrhythmia as an independent predictor of recurrent arrhythmia or sudden death (relative risk, 7.3; 95 percent confidence interval, 2.3 to 23.2; P less than 0.001).

CONCLUSIONS

As compared with metoprolol therapy, electrophysiologically guided antiarrhythmic drug therapy did not improve the overall outcome of patients with sustained ventricular tachyarrhythmias. However, effective suppression of inducible arrhythmia by antiarrhythmic drugs was associated with a better outcome than was lack of suppression.

[Anti-arrhythmia and pro-arrhythmia effects of oral cibenzoline therapy in sustained ventricular tachycardia]

The efficacy and safety of the new class-I antiarrhythmic drug cibenzoline was assessed in 12 patients with spontaneous and inducible ventricular tachycardia. Programmed ventricular stimulation, 24-h ambulatory electrocardiogram (ECG), and continuous ECG monitoring were performed without antiarrhythmic drugs and after oral administration of 254 +/- 80 mg of the substance. Oral cibenzoline suppressed the induction of tachycardia in only one patient. Induction of tachycardia was more difficult in two patients, unchanged in four patients, and easier in two patients. Cycle length of induced tachycardia and QT-interval corrected for frequency were not changed significantly; effective refractory period of the right ventricle was prolonged. Twenty-four hours of ambulatory monitoring during cibenzoline treatment (n = 9) showed no significant increase in the frequency of ventricular premature complexes. However, spontaneous sustained ventricular tachycardia developed in three patients after initiation of cibenzoline treatment. In two patients, termination of induced ventricular tachycardia was significantly more difficult under cibenzoline; several DC-shocks were required to terminate the tachycardia. Thus, the use of oral cibenzoline in patients with sustained spontaneous and inducible ventricular tachycardias showed a low antiarrhythmic efficacy at programmed stimulation and a high incidence of spontaneous ventricular tachycardia.

Influence of assay methods on serum concentrations of digoxin during FAB fragment treatment

The treatment of digoxin intoxication has been revolutionized by digoxin specific antibody fragments (Fab). Serum digoxin concentrations may be inaccurate after this treatment. We report a case of digoxin intoxication where the results of serum concentration determinations were strikingly disparate depending on the assay used. To investigate this discrepancy we compared serum samples spiked with digoxin from 0-50 ng/mL in the presence of increasing concentrations of digoxin specific Fab-fragments. Samples were measured using the Abbott TDx assay with and without ultrafiltration of the sample and the Dade-Stratus radial partition assay. The TDx assay was statistically reduced by the Fab-fragments although the magnitude of the effect was small. The radial partition assay was dramatically affected by the addition of Fab-fragments. The predicted non-Fab bound concentration correlated highly with the measured concentration. When samples were ultrafiltered prior to TDx assay, the measured concentration was dramatically depressed but the regression of predicted non-Fab bound concentration versus observed had a significantly lower slope than for the radial partition assay. We hypothesize that this difference is due to serum protein binding in addition to Fab-fragment binding. We conclude that the radial partition assay gives the best approximation of digoxin concentration remaining unbound to Fab-fragments. Ultrafiltration followed by TDx assay gives an acceptable approximation.

[Therapy of paroxysmal atrial fibrillation. Cardiac glycosides alone or combined with anti-arrhythmia agents?]

In a prospective study 45 patients with paroxysmal atrial fibrillation were randomly assigned to one of three groups (of 15 patients each): group I received oral digoxin, three times 0.125 mg up to twice 0.25 mg daily; group II oral digoxin twice 0.125 mg and quinidine hydrogen sulphate 750-1000 mg daily; group III oral digoxin three times 0.125 mg and flecainide 200-300 mg daily. During a mean observation period of 11 months digoxin alone was significantly less effective (P less than 0.05) in reducing or suppressing paroxysms of atrial fibrillation than digoxin plus quinidine or flecainide. Flecainide with digoxin was more effective than the drug regimen in groups I and II (P less than 0.05). Two patients each in groups I and III had side effects, eight in group II. The results suggest that, at the chosen dosage, flecainide produces fewer side effects than quinidine.