Quantifying the relationship between cell proliferation and morphology during development of the face

Morphogenesis requires highly coordinated, complex interactions between cellular processes: proliferation, migration, and apoptosis, along with physical tissue interactions. How these cellular and tissue dynamics drive morphogenesis remains elusive. Three dimensional (3D) microscopic imaging poses great promise, and generates elegant images. However, generating even moderate through-put quantified images is challenging for many reasons. As a result, the association between morphogenesis and cellular processes in 3D developing tissues has not been fully explored. To address this critical gap, we have developed an imaging and image analysis pipeline to enable 3D quantification of cellular dynamics along with 3D morphology for the same individual embryo. Specifically, we focus on how 3D distribution of proliferation relates to morphogenesis during mouse facial development. Our method involves imaging with light-sheet microscopy, automated segmentation of cells and tissues using machine learning-based tools, and quantification of external morphology via geometric morphometrics. Applying this framework, we show that changes in proliferation are tightly correlated to changes in morphology over the course of facial morphogenesis. These analyses illustrate the potential of this pipeline to investigate mechanistic relationships between cellular dynamics and morphogenesis during embryonic development.

IRONMAN: A Novel International Registry of Men With Advanced Prostate Cancer

PURPOSE

To describe a newly established international registry recruiting diverse patients with advanced prostate cancer across academic and community practices to address unmet needs in this population.

PATIENTS AND METHODS

Initiated in 2017, IRONMAN (International Registry for Men with Advanced Prostate Cancer) is a prospective cohort of patients with advanced prostate cancer. The study will enroll 5,000 patients with metastatic hormone-sensitive prostate cancer (mHSPC) or castration-resistant prostate cancer (CRPC), recruited from Australia, the Bahamas, Barbados, Brazil, Canada, Ireland, Jamaica, Kenya, Nigeria, Norway, South Africa, Spain, Sweden, Switzerland, the United Kingdom, and the United States. The study is collecting datatypes to study variation in care and treatment of advanced prostate cancer across countries and across academic, community-based, and government practices with a focus on clinical outcomes, patient-reported outcomes, epidemiologic data, biologic subtypes, and clinician questionnaires.

RESULTS

Through July 2022, 2,682 eligible patients were enrolled in 11 of 12 active countries. Sixty-six percent of patients have mHSPC, and 34% have CRPC. On the basis of self-report, 11% of patients are Black and 9% are Hispanic. Five Veterans Affairs Medical Centers are enrolling patients. Globally, 23% of patients report being veterans of military service.

CONCLUSION

To our knowledge, this is the first international cohort of people newly diagnosed with advanced prostate cancer designed to describe variations in patient management, experiences, and outcomes. IRONMAN aims to identify optimal treatment sequences to improve survival, understand patient-reported outcomes, and explore novel biomarkers to understand treatment resistance mechanisms. Insights from IRONMAN will inform and guide future clinical management of people with mHSPC and CRPC. This cohort study will provide real-world evidence to facilitate a better understanding of the survivorship of people with advanced prostate cancer.

Fgf8 dosage regulates jaw shape and symmetry through pharyngeal-cardiac tissue relationships

BACKGROUND

Asymmetries in craniofacial anomalies are commonly observed. In the facial skeleton, the left side is more commonly and/or severely affected than the right. Such asymmetries complicate treatment options. Mechanisms underlying variation in disease severity between individuals as well as within individuals (asymmetries) are still relatively unknown.

RESULTS

Developmental reductions in fibroblast growth factor 8 (Fgf8) have a dosage dependent effect on jaw size, shape, and symmetry. Further, Fgf8 mutants have directionally asymmetric jaws with the left side being more affected than the right. Defects in lower jaw development begin with disruption to Meckel's cartilage, which is discontinuous. All skeletal elements associated with the proximal condensation are dysmorphic, exemplified by a malformed and misoriented malleus. At later stages, Fgf8 mutants exhibit syngnathia, which falls into two broad categories: bony fusion of the maxillary and mandibular alveolar ridges and zygomatico-mandibular fusion. All of these morphological defects exhibit both inter- and intra-specimen variation.

CONCLUSIONS

We hypothesize that these asymmetries are linked to heart development resulting in higher levels of Fgf8 on the right side of the face, which may buffer the right side to developmental perturbations. This mouse model may facilitate future investigations of mechanisms underlying human syngnathia and facial asymmetry.

Segmentation of Tissues and Proliferating Cells in Light-Sheet Microscopy Images of Mouse Embryos Using Convolutional Neural Networks

A variety of genetic mutations affect cell proliferation during organism development, leading to structural birth defects. However, the mechanisms by which these alterations influence the development of the face remain unclear. Cell proliferation and its relation to shape variation can be studied using Light-Sheet Microscopy (LSM) imaging across a range of developmental time points using mouse models. The aim of this work was to develop and evaluate accurate automatic methods based on convolutional neural networks (CNNs) for: (i) tissue segmentation (neural ectoderm and mesenchyme), (ii) cell segmentation in nuclear-stained images, and (iii) segmentation of proliferating cells in phospho-Histone H3 (pHH3)-stained LSM images of mouse embryos. For training and evaluation of the CNN models, 155 to 176 slices from 10 mouse embryo LSM images with corresponding manual segmentations were available depending on the segmentation task. Three U-net CNN models were trained optimizing their loss functions, among other hyper-parameters, depending on the segmentation task. The tissue segmentation achieved a macro-average F-score of 0.84, whereas the inter-observer value was 0.89. The cell segmentation achieved a Dice score of 0.57 and 0.56 for nuclear-stained and pHH3-stained images, respectively, whereas the corresponding inter-observer Dice scores were 0.39 and 0.45, respectively. The proposed pipeline using the U-net CNN architecture can accelerate LSM image analysis and together with the annotated datasets can serve as a reference for comparison of more advanced LSM image segmentation methods in future.

Facilitating Constructive Discussions of Difficult Socio-Scientific Issues

Discussion can be an important and powerful tool in efforts to build a more diverse, equitable, and inclusive future for STEM (i.e., science, technology, engineering, and mathematics). However, facilitating discussions on difficult, complex, and often uncomfortable issues, like racism and sexism, can feel daunting. We outline a series of steps that can be used by educators to facilitate productive discussions that empower everyone to listen, contribute, learn, and ultimately act to transform STEM.

Facial shape and allometry quantitative trait locus intervals in the Diversity Outbred mouse are enriched for known skeletal and facial development genes

The biology of how faces are built and come to differ from one another is complex. Discovering normal variants that contribute to differences in facial morphology is one key to untangling this complexity, with important implications for medicine and evolutionary biology. This study maps quantitative trait loci (QTL) for skeletal facial shape using Diversity Outbred (DO) mice. The DO is a randomly outcrossed population with high heterozygosity that captures the allelic diversity of eight inbred mouse lines from three subspecies. The study uses a sample of 1147 DO animals (the largest sample yet employed for a shape QTL study in mouse), each characterized by 22 three-dimensional landmarks, 56,885 autosomal and X-chromosome markers, and sex and age classifiers. We identified 37 facial shape QTL across 20 shape principal components (PCs) using a mixed effects regression that accounts for kinship among observations. The QTL include some previously identified intervals as well as new regions that expand the list of potential targets for future experimental study. Three QTL characterized shape associations with size (allometry). Median support interval size was 3.5 Mb. Narrowing additional analysis to QTL for the five largest magnitude shape PCs, we found significant overrepresentation of genes with known roles in growth, skeletal and facial development, and sensory organ development. For most intervals, one or more of these genes lies within 0.25 Mb of the QTL's peak. QTL effect sizes were small, with none explaining more than 0.5% of facial shape variation. Thus, our results are consistent with a model of facial diversity that is influenced by key genes in skeletal and facial development and, simultaneously, is highly polygenic.

Nonlinear gene expression-phenotype relationships contribute to variation and clefting in the A/WySn mouse

BACKGROUND

Cleft lip and palate is one of the most common human birth defects, but the underlying etiology is poorly understood. The A/WySn mouse is a spontaneously occurring model of multigenic clefting in which 20% to 30% of individuals develop an orofacial cleft. Recent work has shown altered methylation at a specific retrotransposon insertion downstream of the Wnt9b locus in clefting animals, which results in decreased Wnt9b expression.

RESULTS

Using a newly developed protocol that allows us to measure morphology, gene expression, and DNA methylation in the same embryo, we relate gene expression in an individual embryo directly to its three-dimensional morphology for the first time. We find that methylation at the retrotransposon relates to Wnt9b expression and morphology. IAP methylation relates to shape of the nasal process in a manner consistent with clefting. Embryos with low IAP methylation exhibit increased among-individual variance in facial shape.

CONCLUSIONS

Methylation and gene expression relate nonlinearly to nasal process morphology. Individuals at one end of a continuum of phenotypic states display a clinical phenotype and increased phenotypic variation. Variable penetrance and expressivity in this model is likely determined both by among-individual variation in methylation and changes in phenotypic robustness along the underlying liability distribution for orofacial clefting.

The developmental-genetics of canalization

Canalization, or robustness to genetic or environmental perturbations, is fundamental to complex organisms. While there is strong evidence for canalization as an evolved property that varies among genotypes, the developmental and genetic mechanisms that produce this phenomenon are very poorly understood. For evolutionary biology, understanding how canalization arises is important because, by modulating the phenotypic variation that arises in response to genetic differences, canalization is a determinant of evolvability. For genetics of disease in humans and for economically important traits in agriculture, this subject is important because canalization is a potentially significant cause of missing heritability that confounds genomic prediction of phenotypes. We review the major lines of thought on the developmental-genetic basis for canalization. These fall into two groups. One proposes specific evolved molecular mechanisms while the other deals with robustness or canalization as a more general feature of development. These explanations for canalization are not mutually exclusive and they overlap in several ways. General explanations for canalization are more likely to involve emergent features of development than specific molecular mechanisms. Disentangling these explanations is also complicated by differences in perspectives between genetics and developmental biology. Understanding canalization at a mechanistic level will require conceptual and methodological approaches that integrate quantitative genetics and developmental biology.

Developmental nonlinearity drives phenotypic robustness

Robustness to perturbation is a fundamental feature of complex organisms. Mutations are the raw material for evolution, yet robustness to their effects is required for species survival. The mechanisms that produce robustness are poorly understood. Nonlinearities are a ubiquitous feature of development that may link variation in development to phenotypic robustness. Here, we manipulate the gene dosage of a signaling molecule, Fgf8, a critical regulator of vertebrate development. We demonstrate that variation in Fgf8 expression has a nonlinear relationship to phenotypic variation, predicting levels of robustness among genotypes. Differences in robustness are not due to gene expression variance or dysregulation, but emerge from the nonlinearity of the genotype–phenotype curve. In this instance, embedded features of development explain robustness differences. How such features vary in natural populations and relate to genetic variation are key questions for unraveling the origin and evolvability of this feature of organismal development.

Developmental processes often involve nonlinearities, but the consequences for translating genotype to phenotype are not well characterized. Here, Green et al. vary Fgf8 signaling across allelic series of mice and show that phenotypic robustness in craniofacial shape is explained by a nonlinear effect of Fgf8 expression.

Quantifying three-dimensional morphology and RNA from individual embryos

Quantitative analysis of morphogenesis aids our understanding of developmental processes by providing a method to link changes in shape with cellular and molecular processes. Over the last decade, many methods have been developed for 3D imaging of embryos using microCT scanning to quantify the shape of embryos during development. These methods generally involve a powerful, cross-linking fixative such as paraformaldehyde to limit shrinkage during the CT scan. However, the extended time frames that these embryos are incubated in such fixatives prevent use of the tissues for molecular analysis after microCT scanning. This is a significant problem because it limits the ability to correlate variation in molecular data with morphology at the level of individual embryos. Here we outline a novel method that allows RNA, DNA, or protein isolation following CT scan while also allowing imaging of different tissue layers within the developing embryo. We show shape differences early in craniofacial development (E11.5) between common mouse genetic backgrounds, and demonstrate that we are able to generate RNA from these embryos after CT scanning that is suitable for downstream real time PCR (RT-PCR) and RNAseq analyses. Developmental Dynamics 246:431-436, 2017. © 2017 Wiley Periodicals, Inc.

Conditional deletion of AP-2β in mouse cranial neural crest results in anterior segment dysgenesis and early-onset glaucoma

Anterior segment dysgenesis (ASD) encompasses a group of developmental disorders in which a closed angle phenotype in the anterior chamber of the eye can occur and 50% of patients develop glaucoma. Many ASDs are thought to involve an inappropriate patterning and migration of the periocular mesenchyme (POM), which is derived from cranial neural crest cells (NCCs) and mesoderm. Although, the mechanism of this disruption is not well understood, a number of transcriptional regulatory molecules have previously been implicated in ASDs. Here, we investigate the function of the transcription factor AP-2β, encoded by Tfap2b, which is expressed in NCCs and their derivatives. Wnt1-Cre-mediated conditional deletion of Tfap2b in NCCs resulted in post-natal ocular defects typified by opacity. Histological data revealed that the conditional AP-2β NCC knockout (KO) mutants exhibited dysgenesis of multiple structures in the anterior segment of the eye including defects in the corneal endothelium, corneal stroma, ciliary body and disruption in the iridocorneal angle with adherence of the iris to the cornea. We further show that this phenotype leads to a significant increase in intraocular pressure and a subsequent loss of retinal ganglion cells and optic nerve degeneration, features indicative of glaucoma. Overall, our findings demonstrate that AP-2β is required in the POM for normal development of the anterior segment of the eye and that the AP-2β NCC KO mice might serve as a new and exciting model of ASD and glaucoma that is fully penetrant and with early post-natal onset.

Summary: Tissue-specific deletion of transcription factor AP-2β in the neural-crest-derived periocular mesenchyme generates a novel model of anterior segment dysgenesis and early onset glaucoma in mice.

Signals from the brain induce variation in avian facial shape

BACKGROUND

How developmental mechanisms generate the phenotypic variation that is the raw material for evolution is largely unknown. Here, we explore whether variation in a conserved signaling axis between the brain and face contributes to differences in morphogenesis of the avian upper jaw. In amniotes, including both mice and avians, signals from the brain establish a signaling center in the ectoderm (the Frontonasal ectodermal zone or "FEZ") that directs outgrowth of the facial primordia.

RESULTS

Here we show that the spatial organization of this signaling center differs among avians, and these correspond to Sonic hedgehog (Shh) expression in the basal forebrain and embryonic facial shape. In ducks this basal forebrain domain is present almost the entire width, while in chickens it is restricted to the midline. When the duck forebrain is unilaterally transplanted into stage matched chicken embryos the face on the treated side resembles that of the donor.

CONCLUSIONS

Combined with previous findings, these results demonstrate that variation in a highly conserved developmental pathway has the potential to contribute to evolutionary differences in avian upper jaw morphology. Developmental Dynamics 244:1133-1143, 2015. © 2015 Wiley Periodicals, Inc.

Tfap2a-dependent changes in mouse facial morphology result in clefting that can be ameliorated by a reduction in Fgf8 gene dosage

Failure of facial prominence fusion causes cleft lip and palate (CL/P), a common human birth defect. Several potential mechanisms can be envisioned that would result in CL/P, including failure of prominence growth and/or alignment as well as a failure of fusion of the juxtaposed epithelial seams. Here, using geometric morphometrics, we analyzed facial outgrowth and shape change over time in a novel mouse model exhibiting fully penetrant bilateral CL/P. This robust model is based upon mutations in Tfap2a, the gene encoding transcription factor AP-2α, which has been implicated in both syndromic and non-syndromic human CL/P. Our findings indicate that aberrant morphology and subsequent misalignment of the facial prominences underlies the inability of the mutant prominences to fuse. Exencephaly also occured in some of the Tfap2a mutants and we observed additional morphometric differences that indicate an influence of neural tube closure defects on facial shape. Molecular analysis of the CL/P model indicates that Fgf signaling is misregulated in the face, and that reducing Fgf8 gene dosage can attenuate the clefting pathology by generating compensatory changes. Furthermore, mutations in either Tfap2a or Fgf8 increase variance in facial shape, but the combination of these mutations restores variance to normal levels. The alterations in variance provide a potential mechanistic link between clefting and the evolution and diversity of facial morphology. Overall, our findings suggest that CL/P can result from small gene-expression changes that alter the shape of the facial prominences and uncouple their coordinated morphogenesis, which is necessary for normal fusion.

Microfluidic fabrication of 6-methoxyethylamino numonafide-eluting magnetic microspheres

Recently, 6-methoxyethylamino numonafide (MEAN) exhibited potent inhibition of hepatocellular carcinoma (HCC) cell growth and less systemic toxicity than amonafide. MEAN may serve as an ideal candidate for the treatment of HCC; however, liver-directed, selective infusion methods may be critical to maximize the MEAN dose delivered to the targeted tumors. This study describes the microfluidic fabrication of MEAN-eluting ultrasmall superparamagnetic iron oxide (USPIO) nanocluster-containing alginate microspheres (MEAN-magnetic microspheres) intended for selective transcatheter delivery to HCC. The resulting drug delivery platform was mono-disperse, microsphere sizes were readily controlled based on channel flow rates during synthesis procedures, and drug release rates from the microspheres could be readily controlled with the introduction of USPIO nanoclusters. The MR relaxivity properties of the microspheres suggest the feasibility of in vivo imaging after administration, and these microspheres exhibited potent therapeutic effects significantly inhibiting cell growth inducing apoptosis in hepatoma cells.

beta2-agonists promote host defense against bacterial infection in primary human bronchial epithelial cells

Background

Airway epithelial cells are critical in host defense against bacteria including Mycoplasma pneumoniae (Mp) in chronic obstructive pulmonary disease (COPD) and asthma. β2-agonists are mainstay of COPD and asthma therapy, but whether β2-agonists directly affect airway epithelial host defense functions is unclear.

Methods

Epithelial cells from bronchial brushings of normal (n = 8), asthma (n = 8) and COPD (n = 8) subjects were grown in air-liquid interface cultures, and treated with cigarette smoke extract (CSE) and/or Th2 cytokine IL-13, followed by Mp infection and treatment with β2-agonists albuterol and formoterol for up to seven days. Mp and host defense proteins short palate, lung, and nasal epithelial clone 1 (SPLUNC1) and β-defensin-2 were quantified. Expression of β2-adrenergic receptors was also measured by real-time quantitative RT-PCR.

Results

(R)- or racemic albuterol and (R,R)- or racemic formoterol significantly decreased Mp levels in normal and asthma epithelial cells. Normal cells treated with Mp and (R)- or racemic albuterol showed an increase in SPLUNC1, but not in β-defensin-2. COPD cells did not respond to drug treatment with a significant decrease in Mp or an increase in SPLUNC1. IL-13 attenuated drug effects on Mp, and markedly decreased SPLUNC1 and β2-adrenergic receptors.

Conclusions

These results for the first time show that β2-agonists enhance host defense functions of primary bronchial epithelial cells from normal and asthma subjects, which is attenuated by IL-13.

Bevacizumab for recurrent ependymoma

BACKGROUND

Ependymoma is a rare type of glioma, representing 5% of all CNS malignancies. Radiotherapy (RT) is commonly administered, but there is no standard chemotherapy. At recurrence, ependymoma is notoriously refractory to therapy and the prognosis is poor. In recurrent glioblastoma, encouraging responses with bevacizumab have been observed.

METHODS

In this Institutional Review Board-approved study, we retrospectively analyzed the records of 8 adult patients treated for recurrent ependymoma and anaplastic ependymoma with bevacizumab containing chemotherapy regimens. We determined radiographic response (Macdonald criteria), median time to progression (TTP), and median overall survival (OS; Kaplan-Meier method).

RESULTS

There were 4 men and 4 women with a median age of 40 years (range, 20-65). Prior treatment included surgery (n = 8), RT (8), temozolomide (5), and carboplatin (4). Bevacizumab (5-15 mg/kg every 2-3 weeks) was administered alone (2) or concurrently with cytotoxic chemotherapy including irinotecan (3), carboplatin (2), or temozolomide (1). Six patients achieved a partial response (75%) and 1 remained stable for over 8 months. Median TTP was 6.4 months (95% confidence interval 1.4-7.4) and median OS was 9.4 months (95% confidence interval 7.0-not reached), with a median follow-up of 5.2 months among 5 surviving patients (63%).

CONCLUSIONS

The radiographic response rate to bevacizumab-containing regimens is high. A prospective study is warranted.

Impact of cigarette smoke exposure on innate immunity: a Caenorhabditis elegans model

BACKGROUND

Cigarette smoking is the major cause of chronic obstructive pulmonary disease (COPD) and lung cancer. Respiratory bacterial infections have been shown to be involved in the development of COPD along with impaired airway innate immunity.

METHODOLOGY/PRINCIPAL FINDINGS

To address the in vivo impact of cigarette smoke (CS) exclusively on host innate defense mechanisms, we took advantage of Caenorhabditis elegans (C. elegans), which has an innate immune system but lacks adaptive immune function. Pseudomonas aeruginosa (PA) clearance from intestines of C. elegans was dampened by CS. Microarray analysis identified 6 candidate genes with a 2-fold or greater reduction after CS exposure, that have a human orthologue, and that may participate in innate immunity. To confirm a role of CS-down-regulated genes in the innate immune response to PA, RNA interference (RNAi) by feeding was carried out in C. elegans to inhibit the gene of interest, followed by PA infection to determine if the gene affected innate immunity. Inhibition of lbp-7, which encodes a lipid binding protein, resulted in increased levels of intestinal PA. Primary human bronchial epithelial cells were shown to express mRNA of human Fatty Acid Binding Protein 5 (FABP-5), the human orthologue of lpb-7. Interestingly, FABP-5 mRNA levels from human smokers with COPD were significantly lower (p = 0.036) than those from smokers without COPD. Furthermore, FABP-5 mRNA levels were up-regulated (7-fold) after bacterial (i.e., Mycoplasma pneumoniae) infection in primary human bronchial epithelial cell culture (air-liquid interface culture).

CONCLUSIONS

Our results suggest that the C. elegans model offers a novel in vivo approach to specifically study innate immune deficiencies resulting from exposure to cigarette smoke, and that results from the nematode may provide insight into human airway epithelial cell biology and cigarette smoke exposure.

Cryptogenic liver disease in HIV-seropositive men

OBJECTIVES

In the era of highly active antiretroviral therapy (HAART), liver disease has become a leading cause of morbidity and mortality in HIV-seropositive individuals. Although liver disease is commonly caused by viral co-infection, it has also been described in patients without viral hepatitis. In this study, we determined clinical factors associated with the development of cryptogenic liver disease in HIV-infected individuals.

METHODS

HIV-seropositive and -seronegative patients undergoing evaluation for liver transplantation were selected if they met clinical criteria for cryptogenic liver disease. Clinical data were collected retrospectively, and radiological and histological data were reviewed separately.

RESULTS

Nine HIV-seropositive individuals were compared with 41 HIV-seronegative patients with cryptogenic liver disease. Only one HIV-seropositive patient (11%) had cirrhosis, compared to 39 HIV-seronegative patients (93%) (P<0.001). Three HIV-infected patients (33%) had histological evidence of nodular regenerative hyperplasia. HIV-seropositive patients had significantly lower body mass indices, and lower Child-Pugh-Turcotte and Model for Endstage Liver Disease scores than HIV-seronegative patients (P<0.05).

CONCLUSIONS

Advanced cryptogenic liver disease in HIV-infected patients is infrequently caused by cirrhosis, and more frequently by nodular regenerative hyperplasia. This disease entity may become more common in the HAART era, and may contribute to an increased morbidity in HIV-infected individuals.

Bevacizumab and chemotherapy for recurrent glioblastoma: a single-institution experience

OBJECTIVE

Bevacizumab has been shown to be effective in the treatment of recurrent glioblastoma in combination with chemotherapy compared with historic controls but not in randomized trials.

METHODS

We conducted a retrospective analysis of patients treated for recurrent glioblastoma with bevacizumab vs a control group of patients, comparing progression-free survival (PFS) and overall survival (OS) between the two groups, and performed subgroup analysis based on age and performance status. Expression of vascular endothelial growth factor (VEGF) based on age was examined using DNA microarray analysis. We also evaluated the impact of bevacizumab on quality of life.

RESULTS

We identified 44 patients who received bevacizumab and 79 patients who had not been treated with bevacizumab. There was a significant improvement in PFS and OS in the bevacizumab-treated group. Patients of older age (> or =55 years) and poor performance status (Karnofsky Performance Status < or =80) had significantly better PFS when treated with bevacizumab, and bevacizumab-treated older patients had significantly increased OS. VEGF expression was significantly higher in older glioblastoma patients (aged > or =55 years). Patients treated with bevacizumab also required less dexamethasone use and maintained their functional status longer than the control group.

CONCLUSIONS

Bevacizumab in combination with chemotherapy may be a more effective treatment for recurrent glioblastoma and warrants further randomized prospective studies to determine its effect on survival. Bevacizumab also has more effect in those with older age and might reflect biologic differences in glioblastoma in different age groups as seen with the expression of vascular endothelial growth factor.

Embryo as epiphenomenon: some cultural, social and economic forces driving the stem cell debate

Our human embryonic stem cell debates are not simply about good or bad ethical arguments. The fetus and the embryo have instead become symbols for a larger set of value conflicts occasioned by social and cultural changes. Beneath our stem cell debates lie conflicts between those who would privilege scientific progress and individual choice and others who favour the sanctity of family life and traditional family roles. Also at work, on both the national and international levels, is the use of the embryo by newly emergent social groups to express resentment against cultural elites. The organisational needs of religious groups have also played a role, with the issue of protection of the embryo and fetus serving as a useful means of rallying organisational allegiance in the Roman Catholic and evangelical communities. Because the epiphenomenal moral positions on the status and use of the embryo are driven by the powerful social, cultural or economic forces beneath them, they will most likely change only with shifts in the underlying forces that sustain them.

Outcome for adult contacts of smear-positive pulmonary tuberculosis in the absence of X-ray follow-up: 2000-03

The effects of the policy change in X-ray follow-up of adult tuberculin-positive close contacts of sputum microscopy positive pulmonary tuberculosis made by the Joint Tuberculosis Committee of the British Thoracic Society in 2000 were monitored prospectively from late 2000 until the end of 2003. No cases in contacts that could have been detected by interval X-rays at three and 12 months were found. The data, on 291 cases, support the abandonment of X-ray follow-up in favour of an 'inform and advise' strategy after an initial normal chest X-ray in this category of tuberculosis contact.

Inhibiting mild steel corrosion from sulfate-reducing bacteria using antimicrobial-producing biofilms in Three-Mile-Island process water

Biofilms were used to produce gramicidin S (a cyclic decapeptide) to inhibit corrosion-causing, sulfate-reducing bacteria (SRB). In laboratory studies these biofilms protected mild steel 1010 continuously from corrosion in the aggressive, cooling service water of the AmerGen Three-Mile-Island (TMI) nuclear plant, which was augmented with reference SRB. The growth of both reference SRB (Gram-positive Desulfosporosinus orientis and Gram-negative Desulfovibrio vulgaris) was shown to be inhibited by supernatants of the gramicidin-S-producing bacteria as well as by purified gramicidin S. Electrochemical impedance spectroscopy and mass loss measurements showed that the protective biofilms decreased the corrosion rate of mild steel by 2- to 10-fold when challenged with the natural SRB of the TMI process water supplemented with D. orientis or D. vulgaris. The relative corrosion inhibition efficiency was 50-90% in continuous reactors, compared to a biofilm control which did not produce the antimicrobial gramicidin S. Scanning electron microscope and reactor images also revealed that SRB attack was thwarted by protective biofilms that secrete gramicidin S. A consortium of beneficial bacteria (GGPST consortium, producing gramicidin S and other antimicrobials) also protected the mild steel.

Hepatic canalicular membrane transport of bile salt in C57L/J and AKR/J mice: implications for cholesterol gallstone formation

C57L/J (gallstone-susceptible) and AKR/J (gallstone-resistant) mice have been utilized for quantitative trait loci (QTL) analysis to identify the Lith 1 locus for cholelithiasis. Abcb11 encodes for the liver canalicular membrane bile salt export pump (BSEP), which maps to this QTL and is a candidate gene for Lith 1. We investigated the transmembrane transport of taurocholate in canalicular liver membrane vesicles isolated from these murine strains. Canalicular liver plasma membranes (cLPM) and RNA were isolated from C57L/J and AKR/J mice livers, and were utilized for Northern and Western blot analysis and functional (3)H-taurocholate uptake studies. ATP-dependent (3)H-taurocholate uptake was significantly higher in AKR/J, compared to C57L/J mice. V(max) was 127 vs. 42 pmol TC/mg/s in the murine strains, respectively, while K(m) was unchanged. In contrast, gene and protein expression of hepatic Abcb11 was increased three-fold in C57L/J, compared to AKR/J mice. Thus, Abcb11 bile salt transport activity per unit protein was reduced nine-fold in the C57L/J, compared to AKR/J mice. In contrast, canalicular membrane cholesterol:phospholipid content was also significantly higher in the C57L/J mice. We conclude that gallstone-susceptible C57L/J mice demonstrate increased gene and canalicular membrane expression of Abcb11, however, taurocholate transport is functionally diminished. The latter may be due to the increased cholesterol membrane content of the cLPM in C57L/J mice. These findings may be important for the pathogenesis of gallstone formation.

Determining access to assisted reproductive technology: reactions of clinic directors to ethically complex case scenarios

BACKGROUND

Our aim was to increase understanding of how patient selection is handled by assisted reproductive technology (ART) clinicians.

METHODS

Ethically complex case scenarios were evaluated by the directors of USA ART clinics. Scenarios included using a son as sperm donor for his father, sex selection without associated disease, treatment of morally irresponsible couples, and a dispute over embryo disposition. Respondents reviewed eight scenarios and gave their opinions on whether to offer treatment. Reasons given for these decisions were placed into one of 13 categories.

RESULTS

Survey response rate was 57%. Between 3 and 50% of respondents would treat in each case. Of reasons given, 'conditional' responses (requiring counselling, blood tests or agreement to other 'conditions') were common (31.4%). Non-maleficence (risk) accounted for 29.4% of responses, philosophy of medicine 18.9%, respect for patient autonomy 5.9% and legal concerns 4.6%. Discrimination and threats were each significant in one case. Reasons evoking absolutist beliefs, personal discomfort, commitment to justice, religion and ethical relativism were rare.

CONCLUSIONS

Clinicians felt conflict between a desire to respect patient autonomy and their discomfort over the risk associated with the procedure. They raised concerns about misuse of medical technology. Attempts to resolve complex issues through negotiation and compromise were common.

An assessment of sleep disturbance in patients before and after total hip arthroplasty

Patients with osteoarthritis commonly complain of sleep disturbance that may be due to pain. Osteoarthritic hip pain is commonly alleviated by total hip arthroplasty (THA). Forty-eight patients waiting for THA completed a sleep questionnaire and were monitored using actigraphy and sleep diaries for 4 to 5 nights, 1 month before and 3 months after surgery. For the group as a whole, significant improvements were seen in subjective and objective measures of sleep after THA. In this study, 75% of participants reported that their sleep was never or rarely disturbed by hip pain after surgery. Actigraphy indicated significant reductions in time in bed and activity during sleep, more efficient sleep and less fragmented (restless) sleep. Differences between patients aged < 65 and > or = 65 years were observed. These findings support the hypothesis that relief from the pain of osteoarthritis as a result of THA improves sleep quality. Improvements in sleep contribute to the improved quality of life and day-to-day functioning seen after THA.

Outcome of the treatment of culture negative tuberculosis (respiratory and non-respiratory): Blackburn 1996-2000

OBJECTIVE

To determine the outcome of treating patients without culture confirmation of tuberculosis, with a regimen of two months of isoniazid, rifampicin, pyrazinamide and ethambutol followed by four months of isoniazid and rifampicin (2HRZE/4HR) in a setting with a rate of isoniazid resistance of 7.5% in culture confirmed cases.

SETTING

Tuberculosis patients treated in the Blackburn, Hyndburn and Ribble Valley districts of the UK between 1996 and 2000 inclusive.

METHODS

Patients from a detailed prospective clinical and epidemiological data base for all tuberculosis patients were studied for the years 1996-2000.

RESULTS

One hundred and fourteen cases, all but two of Indian subcontinent ethnic origin, without culture confirmation had received 2HRZE/4HR. Twenty had pulmonary, 55 other respiratory and 39 non-respiratory tuberculosis. There was no bacteriologically confirmed relapse, 1 case was retreated as a clinical relapse.

CONCLUSION

The treatment of tuberculosis cases without culture confirmation with a regimen of 2HRZE/4HR gives highly acceptable results. The clinical relapse rate was 0.85% (1/114), and the cure rate 99.15%.

Tuberculosis treatment outcome monitoring: Blackburn 1988-2000

SETTING

All cases of tuberculosis in a high prevalence district (population 269,000) of England.

OBJECTIVE

To analyse the tuberculosis programme outcome for confirmed pulmonary tuberculosis, and all other categories of cases for 1988-2000 inclusive.

DESIGN

The outcome of all cases treated during the period 1988-2000 inclusive was assessed by agreed European outcome criteria, retrospectively for 1988-1998 and prospectively for 1999-2000.

RESULTS

A total of 729 tuberculosis cases were notified, with 209 definite (culture-positive) pulmonary cases. Of the 205 definite pulmonary cases treated in life, 182 received self-administered treatment (SAT) and 23 directly observed treatment (DOT), with an 88% cure/completion rate and a 12% death rate. The relapse rate for SAT was 1/182 (0.5%) and 1/23 for DOT (4.3%). The cure/completion rate for all patients together was 94.3%, with a relapse rate of 0.8%.

CONCLUSION

In this resource-rich setting, treatment largely by SAT, but carefully monitored, gives a very high cure/completion rate. Universal rather than selective DOT would make little additional impact on patient outcome. These outcomes are not likely to be reproducible, however, with SAT in a resource-poor setting.

An empirical quantitative framework for the seasonal population dynamics of the tick Ixodes ricinus

The wide geographic and climatic range of the tick Ixodes ricinus, and the consequent marked variation in its seasonal population dynamics, have a direct impact on the transmission dynamics of the many pathogens vectored by this tick species. We use long-term observations on the seasonal abundance and fat contents (a marker of physiological ageing) of ticks, and contemporaneous microclimate at three field sites in the UK, to establish a simple quantitative framework for the phenology (i.e. seasonal cycle of development) of I. ricinus as a foundation for a generic population model. An hour-degree tick inter-stadial development model, driven by soil temperature and including diapause, predicts the recruitment (i.e. emergence from the previous stage) of a single cohort of each stage of ticks each year in the autumn. The timing of predicted emergence coincides exactly with the new appearance of high-fat nymphs and adults in the autumn. Thereafter, fat contents declined steadily until unfed ticks with very low energy reserves disappeared from the questing population within about 1 year from their recruitment. Very few newly emerged ticks were counted on the vegetation in the autumn, but they appeared in increasing numbers through the following spring. Larger ticks became active and subsequently left the questing population before smaller ones. Questing tick population dynamics are determined by seasonal patterns of tick behaviour, host-contact rates and mortality rates, superimposed on a basal phenology that is much less complex than has hitherto been portrayed.

Double Z-pinch hohlraum drive with excellent temperature balance for symmetric inertial confinement fusion capsule implosions

A double Z pinch driving a cylindrical secondary hohlraum from each end has been developed which can indirectly drive intertial confinement fusion capsule implosions with time-averaged radiation fields uniform to 2%-4%. 2D time-dependent view factor and 2D radiation hydrodynamic simulations using the measured primary hohlraum temperatures show that capsule convergence ratios of at least 10 with average distortions from sphericity of <Delta r>/r<or=30% are possible on the Z accelerator and may meet radiation symmetry requirements for scaling to fusion yields of >200 MJ.

Diagnosis and management of the "difficult" abdominal aortic aneurysm: pararenal aneurysms, inflammatory aneurysms, and horseshoe kidney

All "difficult" abdominal aortic aneurysms-whether pararenal or inflammatory or associated with abnormal renal parenchymal anatomy-often best are approached with some combination of retroperitoneal exposure and supraceliac clamping. Preoperative recognition that an unusual case may exist, complete and appropriate imaging and formulation of a sensible plan before operation are absolutely critical to success. Following such a plan can convert a relatively complex situation into a relatively simple one.

Four moral questions for human embryonic stem cell research

Human embryonic stem cell research offers great promise for the treatment of many serious disease conditions in a variety of medical areas, including wound healing. Before this promise can be realized, society and individual researchers, clinicians, and patients will have to answer four ethical questions: 1) Can we ever intentionally destroy a human embryo? 2) Can we benefit from others' destruction of embryos? 3) Can we create an embryo to destroy it? 4) Can we clone human embryos? After outlining the issues raised by each question, the author concludes by indicating his own affirmative answer to each of these questions.

Safety and efficacy of limited-dose tissue plasminogen activator in acute vascular occlusion

OBJECTIVE

The purposes of this study were to evaluate the safety and efficacy of limited-dose tissue plasminogen activator (t-PA) in patients with acute vascular occlusion and to compare these results with those obtained in equivalent patients receiving urokinase.

METHODS

We compared the results of 60 patients receiving catheter-directed urokinase from November 1997 to November 1998 (240,000 units/h x 4 h, 120,000 units/h thereafter for a maximum of 48 h) with those of 45 patients receiving catheter-directed t-PA from November 1998 to August 2000 (2 mg/h, total dose < or =100 mg) for acute arterial occlusion (AAO) and acute venous occlusion (AVO). Interventional approaches such as cross-catheter and coaxial techniques were used to reduce the dose of lytic agent needed to achieve pre-lysis-treatment goals (eg, complete lysis of all thrombus/unmasking graft stenosis or establishing outflow target). Statistical analysis was performed using Student t test and Fisher exact test.

RESULTS

The urokinase and t-PA groups were comparable with regard to age, comorbidities (coronary artery disease, hypertension, diabetes, renal insufficiency, smoking), duration of ischemic or occlusive symptoms, location of occlusive process, pretreatment with warfarin, and thrombotic versus embolic and native versus graft occlusion in patients with AAO. In patients with AAO and in those with AVO, t-PA was equivalent to or better than urokinase with regard to percent of clot lysis, incidence of major bleeding complications, limb salvage, and mortality. Achievement of pretreatment goals (arterial patients only) was 50% for urokinase patients and 76% for t-PA patients (P =.02). Analysis of success in individual pretreatment-goal achievement showed urokinase and t-PA to be equivalent in unmasking stenoses (85% and 84%, respectively; P = NS), whereas t-PA was superior to urokinase in the more critical task of establishing run-off (39% versus 81% for urokinase and t-PA, respectively; P =.001). Additional interventions, either endovascular or surgical, were required in 60% and 51% (P = NS) of patients receiving urokinase and t-PA, respectively, for AAO, and in 54% and 62% (P = NS) of patients receiving urokinase and t-PA, respectively, for AVO.

CONCLUSIONS

Limited-dose t-PA is a safe and effective therapy for AAO and AVO when administered by experienced teams using innovative but well-established interventional techniques.

Mechanism of indinavir-induced hyperbilirubinemia

Indinavir is a viral protease inhibitor used for the treatment of HIV infection. Unconjugated hyperbilirubinemia develops in up to 25% of patients receiving indinavir, prompting drug discontinuation and further clinical evaluation in some instances. We postulated that this side-effect is due to indinavir-mediated impairment of bilirubin UDP-glucuronosyltransferase (UGT) activity and would be most pronounced in individuals with reduced hepatic enzyme levels, as occurs in approximately 10% of the population manifesting Gilbert's syndrome. This hypothesis was tested in vitro, in the Gunn rat model of UGT deficiency, and in HIV-infected patients with and without the Gilbert's polymorphism. Indinavir was found to competitively inhibit UGT enzymatic activity (K(I) = 183 microM) while concomitantly inducing hepatic bilirubin UGT mRNA and protein expression. Although oral indinavir increased plasma bilirubin levels in wild-type and heterozygous Gunn rats, the mean rise was significantly greater in the latter group of animals. Similarly, serum bilirubin increased by a mean of 0.34 mg/dl in indinavir-treated HIV patients lacking the Gilbert's polymorphism versus 1.45 mg/dl in those who were either heterozygous or homozygous for the mutant allele. Whereas saquinavir also competitively inhibits UGT activity, this drug has not been associated with hyperbilirubinemia, most likely because of the higher K(I) (360 microM) and substantially lower therapeutic levels as compared with indinavir. Taken together, these findings indicate that elevations in serum-unconjugated bilirubin associated with indinavir treatment result from direct inhibition of bilirubin-conjugating activity.

Drug resistance trends in M. tuberculosis: Blackburn 1990-1999

SETTING

Blackburn, United Kingdom.

OBJECTIVE

To describe the drug resistance data for Mycobacterium tuberculosis in white and Indian Subcontinent (ISC) ethnic patients in a high prevalence district in the United Kingdom (UK) over a 10-year period.

DESIGN

Data from a detailed prospective clinical and epidemiological database of all notified patients were examined for the years 1990-1999 inclusive.

RESULTS

Primary isoniazid resistance was found in 17/229 (7.4%) of ISC and 3/67 (4.5%) of white isolates. There was no statistical difference in the rates of drug resistance in those of ISC ethnic origin, whether they were ISC or UK born and whether or not they had made return visits to the ISC.

CONCLUSION

The rate of primary isoniazid resistance remains between 5-10% in ISC patients in Blackburn, showing no fall from previous surveys. The rate of drug resistance was not lower in those born in the UK, irrespective of whether return visits had been made to the ISC. These data will need to be further monitored.

Clinical implications of internal iliac artery embolization in endovascular repair of aortoiliac aneurysms

To overcome constraints imposed by iliac artery anatomy, the anatomic inclusion criteria for endovascular aortic aneurysm repair can be extended by means of intentional coil occlusion of one or both internal iliac arteries and extension of the distal limb of the graft into an external iliac artery. We reviewed our experience with this intervention to determine the safety and efficacy of this approach to aneurysm repair. Over a 30-month period, 84 patients underwent endovascular abdominal aortic aneurysm repair; 23 underwent intentional unilateral (22) or bilateral (1) internal iliac artery occlusion. Morbidity, mortality, and long-term clinical outcomes were evaluated in these 23 patients. Patients were specifically questioned about exercise-induced buttock and extremity symptoms. Our results showed that intentional internal iliac artery embolization to allow endovascular repair of abdominal aortic aneurysms is accompanied by significant morbidity and should be approached with caution.

External beam irradiation for inhibition of intimal hyperplasia following prosthetic bypass: preliminary results

To determine whether external beam irradiation delivered immediately after graft implantation can inhibit anastomotic intimal hyperplasia (IH) 1 month following polytetrafluoroethylene (PTFE) bypass in a sheep carotid artery model, 23 sheep underwent bilateral bypass of the ligated common carotid artery with 8-mm PTFE immediately followed by a single dose of irradiation (15, 21, or 30 Gy) to one side. The 15 animals with bilaterally patent grafts were euthanized at 1 month and graft-arterial anastomoses harvested. Using computer-aided image analysis, IH areas and thicknesses were measured. Graft patency in this model was 83% at 1 month and did not differ according to treatment administered. In the control animals, IH was greatest at mid-anastomosis, but minimal within the native vessel. All three radiation doses markedly inhibited mid-anastomotic IH area and thickness. At the proximal anastomosis, 30 Gy reduced the IH area 20-fold, from 2.06 to 0.14 mm2 (p < 0.0001 by ANOVA), and IH thickness 70-fold, from 29.0 to 0.4 micron (p < 0.0002); similar effects were seen at the distal anastomosis. No adverse effects of radiation treatment were observed. External beam irradiation in doses of 15 to 30 Gy delivered in a single fraction immediately after operation markedly inhibits development of intimal hyperplasia 1 month following end-to-side anastomosis with PTFE in sheep.

What does it mean to use someone as "a means only": rereading Kant

Debates about commodification in bioethics frequently appeal to Kant's famous second formulation of the categorical imperative, the formula requiring us to treat the rational (human) being as "an end in itself" and "never as a means only." In the course of her own treatment of commodification, Margaret Jane Radin observes that Kant's application of this formula "does not generate noncontroversial particular consequences." This is so, I argue, because Kant offers three different--and largely incompatible--interpretations of the formula. One focuses on the obligation to preserve rational willing; the second stresses respect for human (physical) dignity and integrity; the third views respect for others as "ends in themselves" as primarily involving a willingness to govern one's conduct by a procedure of impartial co-legislation. Only the third of these interpretations, I conclude, offers a reasonable and coherent approach to moral judgment about the limits of commodification.

Are there still effects on Indian Subcontinent ethnic tuberculosis of return visits?: a longitudinal study 1978-97

OBJECTIVE

To assess whether return visits to the Indian Subcontinent (ISC) are associated with increased risks of developing clinical tuberculosis.

METHODS

Descriptive analysis of epidemiological records over a period of 1978-97 inclusive in Blackburn, Hyndburn and Ribble Valley for individuals of ISC ethnic origin notified with tuberculosis. Those cases diagnosed through local contact tracing exercises were excluded.

RESULTS

Of 1032 eligible individuals notified with tuberculosis, 228 (22.1%) reported prior visits to the ISC. Of these 151 (66%) reported having visits within 3 years of that notification, including 60% of the United Kingdom (U.K.) born without prior exposure to the ISC.

CONCLUSION

The clinical observations are consistent with the hypothesis that return visits to the ISC carry a risk of acquiring tuberculosis. This cannot be confirmed, however, without information about the return visits in the ISC population as a whole. A case-control study may be required to confirm the hypothesis.

shygrl1 is a mutant affected in multiple aspects of photomorphogenesis

We have used a counter-selection strategy based on aberrant phytochrome regulation of an Lhcb gene to isolate an Arabidopsis mutant designated shygrl1 (shg1). shg1 seedlings have reduced phytochrome-mediated induction of the Lhcb gene family, but normal phytochrome-mediated induction of several other genes, including the rbcS1a gene. Additional phenotypes observed in shg1 plants include reduced chlorophyll in leaves and additional photomorphogenic abnormalities when the seedlings are grown on medium containing sucrose. Mutations in the TATA-proximal region of the Lhcb1*3 promoter that are known to be important for phytochrome regulation affected reporter gene expression in a manner similar to the shg1 mutation. Our results are consistent with the possibility that the mutation either leads to defective chloroplast development or to aberrant phytochrome regulation. They also add to the evidence of complex interactions between light- and sucrose-regulated pathways.

Alcohol withdrawal after open aortic surgery

This study was designed to test the hypothesis that unexpected alcohol withdrawal-like syndrome (AWLS) is more common following aortic, but not other, vascular or nonvascular procedures. All patients undergoing open aortic surgery at our institution in 1997 who survived at least 48 hr were identified, as were those undergoing carotid endarterectomy, infrainguinal bypass, and total colectomy. AWLS was defined as prolonged confusion or agitation and response to conventional treatment for withdrawal, providing that all other sources had been ruled out or a significant history was present. Our results show that, for unknown reasons, AWLS is more common after aortic surgery than after other vascular and high-stress, nonaortic intraabdominal procedures at our institution, and is associated with increased length of stay and morbidity. Because prophylaxis may improve outcome, better efforts to identify patients at risk are required.

Access to services at assisted reproductive technology clinics: a survey of policies and practices

OBJECTIVE

Our goal was to investigate policy on patient access to services at assisted reproductive technology clinics in the United States.

STUDY DESIGN

Surveys asked about a variety of ethically and socially challenging cases and were mailed to directors of all Society for Assisted Reproductive Technology-associated assisted reproductive technology clinics.

RESULTS

Written policies on access to services are present at 40% of assisted reproductive technology clinics. Universal agreement was not found on any issue; 79% of clinics treat single women, 27% treat patients with a history of schizophrenia, 10% treat patients who use alcohol excessively, 7% treat human immunodeficiency virus-positive women, and 2% would treat patients previously convicted of child abuse. A breakdown of the responses indicated that some clinics are more permissive in terms of access to services than others, whereas some are more restrictive.

CONCLUSIONS

The data demonstrate considerable variability in policy among clinics on most access-to-services questions. The results highlight the importance of ongoing discussion of the ethical and legal issues related to access and the need to develop consistent methods to deal with complex cases.