Microscale visualization of cellular features in adult macaque visual cortex

Expansion microscopy and light sheet imaging enable fine-scale resolution of intracellular features that comprise neural circuits. Most current techniques visualize sparsely distributed features across whole brains or densely distributed features within individual brain regions. Here, we visualize dense distributions of immunolabeled proteins across early visual cortical areas in adult macaque monkeys. This process may be combined with multiphoton or magnetic resonance imaging to produce multimodal atlases in large, gyrencephalic brains.

Neuronal wiring diagram of an adult brain

Connections between neurons can be mapped by acquiring and analyzing electron microscopic (EM) brain images. In recent years, this approach has been applied to chunks of brains to reconstruct local connectivity maps that are highly informative, yet inadequate for understanding brain function more globally. Here, we present the first neuronal wiring diagram of a whole adult brain, containing 5×107 chemical synapses between ~130,000 neurons reconstructed from a female Drosophila melanogaster. The resource also incorporates annotations of cell classes and types, nerves, hemilineages, and predictions of neurotransmitter identities. Data products are available by download, programmatic access, and interactive browsing and made interoperable with other fly data resources. We show how to derive a projectome, a map of projections between regions, from the connectome. We demonstrate the tracing of synaptic pathways and the analysis of information flow from inputs (sensory and ascending neurons) to outputs (motor, endocrine, and descending neurons), across both hemispheres, and between the central brain and the optic lobes. Tracing from a subset of photoreceptors all the way to descending motor pathways illustrates how structure can uncover putative circuit mechanisms underlying sensorimotor behaviors. The technologies and open ecosystem of the FlyWire Consortium set the stage for future large-scale connectome projects in other species.

A consensus cell type atlas from multiple connectomes reveals principles of circuit stereotypy and variation

The fruit fly Drosophila melanogaster combines surprisingly sophisticated behaviour with a highly tractable nervous system. A large part of the fly's success as a model organism in modern neuroscience stems from the concentration of collaboratively generated molecular genetic and digital resources. As presented in our FlyWire companion paper ¹ , this now includes the first full brain connectome of an adult animal. Here we report the systematic and hierarchical annotation of this ∼130,000-neuron connectome including neuronal classes, cell types and developmental units (hemilineages). This enables any researcher to navigate this huge dataset and find systems and neurons of interest, linked to the literature through the Virtual Fly Brain database ² . Crucially, this resource includes 4,179 cell types of which 3,166 consensus cell types are robustly defined by comparison with a second dataset, the "hemibrain" connectome ³ . Comparative analysis showed that cell type counts and strong connections were largely stable, but connection weights were surprisingly variable within and across animals. Further analysis defined simple heuristics for connectome interpretation: connections stronger than 10 unitary synapses or providing >1% of the input to a target cell are highly conserved. Some cell types showed increased variability across connectomes: the most common cell type in the mushroom body, required for learning and memory, is almost twice as numerous in FlyWire than in the hemibrain. We find evidence for functional homeostasis through adjustments of the absolute amount of excitatory input while maintaining the excitation-inhibition ratio. Finally, and surprisingly, about one third of the cell types recorded in the hemibrain connectome could not be robustly identified in the FlyWire connectome, cautioning against defining cell types based on single connectomes. We propose that a cell type should be robust to inter-individual variation, and therefore defined as a group of cells that are more similar to cells in a different brain than to any other cell in the same brain. We show that this new definition can be consistently applied to whole connectome datasets. Our work defines a consensus cell type atlas for the fly brain and provides both an intellectual framework and open source toolchain for brain-scale comparative connectomics.

Application of the Lugano Classification for Initial Evaluation, Staging, and Response Assessment of Hodgkin and Non-Hodgkin Lymphoma: The PRoLoG Consensus Initiative (Part 2-Technical)

The aim of this initiative was to provide consensus recommendations from a consortium of academic and industry experts in the field of lymphoma and imaging for the consistent application of imaging assessment with the Lugano classification. Methods: Consensus was obtained through a series of meetings from July 2019 to October 2021 sponsored by the PINTaD (Pharma Imaging Network for Therapeutics and Diagnostics) as part of the ProLoG (PINTaD RespOnse criteria in Lymphoma wOrking Group) consensus initiative. Results: Consensus recommendations encompass all technical imaging aspects of the Lugano classification. Some technical considerations for PET/CT and diagnostic CT are clarified with regards to required imaging series and scan visits, as well as acquisition and reconstruction of PET images and influence of lesion size and background activity. Recommendations are given on the role of imaging and clinical reviewers as well as on training and monitoring. Finally, an example template of an imaging case report form is provided to support efficient collection of data with Lugano Classification. Conclusion: Consensus recommendations are made to comprehensively address technical and imaging areas of inconsistency and ambiguity in the classification encountered by end users. Such guidance should be used to support standardized acquisition and evaluation with the Lugano 2014.

Application of the Lugano Classification for Initial Evaluation, Staging, and Response Assessment of Hodgkin and Non-Hodgkin Lymphoma: The PRoLoG Consensus Initiative (Part 1-Clinical)

Our objective was to provide consensus recommendations from a consortium of academic and industry experts in the field of lymphoma and imaging for consistent application of the Lugano classification. Methods: Consensus was obtained through a series of meetings from July 2019 until September 2021 sponsored by the Pharma Imaging Network for Therapeutics and Diagnostics (PINTaD) as part of the PINTaD Response Criteria in Lymphoma Working Group (PRoLoG) consensus initiative. Results: Consensus recommendations clarified technical considerations for PET/CT and diagnostic CT from the Lugano classification, including updating the FDG avidity of different lymphoma entities, clarifying the response nomenclature, and refining lesion classification and scoring, especially with regard to scores 4 and 5 and the X category of the 5-point scale. Combination of metabolic and anatomic responses is clarified, as well as response assessment in cases of discordant or missing evaluations. Use of clinical data in the classification, especially the requirement for bone marrow assessment, is further updated on the basis of lymphoma entities. Clarification is provided with regard to spleen and liver measurements and evaluation, as well as nodal response. Conclusion: Consensus recommendations are made to comprehensively address areas of inconsistency and ambiguity in the classification encountered during response evaluation by end users, and such guidance should be used as a companion to the 2014 Lugano classification.

Structured sampling of olfactory input by the fly mushroom body

Associative memory formation and recall in the fruit fly Drosophila melanogaster is subserved by the mushroom body (MB). Upon arrival in the MB, sensory information undergoes a profound transformation from broadly tuned and stereotyped odorant responses in the olfactory projection neuron (PN) layer to narrowly tuned and nonstereotyped responses in the Kenyon cells (KCs). Theory and experiment suggest that this transformation is implemented by random connectivity between KCs and PNs. However, this hypothesis has been challenging to test, given the difficulty of mapping synaptic connections between large numbers of brain-spanning neurons. Here, we used a recent whole-brain electron microscopy volume of the adult fruit fly to map PN-to-KC connectivity at synaptic resolution. The PN-KC connectome revealed unexpected structure, with preponderantly food-responsive PN types converging at above-chance levels on downstream KCs. Axons of the overconvergent PN types tended to arborize near one another in the MB main calyx, making local KC dendrites more likely to receive input from those types. Overconvergent PN types preferentially co-arborize and connect with dendrites of αβ and α'β' KC subtypes. Computational simulation of the observed network showed degraded discrimination performance compared with a random network, except when all signal flowed through the overconvergent, primarily food-responsive PN types. Additional theory and experiment will be needed to fully characterize the impact of the observed non-random network structure on associative memory formation and recall.

A scalable and modular automated pipeline for stitching of large electron microscopy datasets

Serial-section electronmicroscopy (ssEM) is themethod of choice for studyingmacroscopic biological samples at extremely high resolution in three dimensions. In the nervous system, nanometer-scale images are necessary to reconstruct dense neural wiring diagrams in the brain, so called connectomes. In order to use this data, consisting of up to 10⁸ individual EM images, it must be assembled into a volume, requiring seamless 2D stitching from each physical section followed by 3D alignment of the stitched sections. The high throughput of ssEM necessitates 2D stitching to be done at the pace of imaging, which currently produces tens of terabytes per day. To achieve this, we present a modular volume assembly software pipeline ASAP (Assembly Stitching and Alignment Pipeline) that is scalable to datasets containing petabytes of data and parallelized to work in a distributed computational environment. The pipeline is built on top of the Render (27) services used in the volume assembly of the brain of adult Drosophilamelanogaster (30). It achieves high throughput by operating on themeta-data and transformations of each image stored in a database, thus eliminating the need to render intermediate output. ASAP ismodular, allowing for easy incorporation of new algorithms without significant changes in the workflow. The entire software pipeline includes a complete set of tools for stitching, automated quality control, 3D section alignment, and final rendering of the assembled volume to disk. ASAP has been deployed for continuous stitching of several large-scale datasets of the mouse visual cortex and human brain samples including one cubic millimeter of mouse visual cortex (28; 8) at speeds that exceed imaging. The pipeline also has multi-channel processing capabilities and can be applied to fluorescence and multi-modal datasets like array tomography.

A Complete Electron Microscopy Volume of the Brain of Adult Drosophila melanogaster

Drosophila melanogaster has a rich repertoire of innate and learned behaviors. Its 100,000-neuron brain is a large but tractable target for comprehensive neural circuit mapping. Only electron microscopy (EM) enables complete, unbiased mapping of synaptic connectivity; however, the fly brain is too large for conventional EM. We developed a custom high-throughput EM platform and imaged the entire brain of an adult female fly at synaptic resolution. To validate the dataset, we traced brain-spanning circuitry involving the mushroom body (MB), which has been extensively studied for its role in learning. All inputs to Kenyon cells (KCs), the intrinsic neurons of the MB, were mapped, revealing a previously unknown cell type, postsynaptic partners of KC dendrites, and unexpected clustering of olfactory projection neurons. These reconstructions show that this freely available EM volume supports mapping of brain-spanning circuits, which will significantly accelerate Drosophila neuroscience. VIDEO ABSTRACT.

Reader Training for the Restaging of Biochemically Recurrent Prostate Cancer Using 18F-Fluciclovine PET/CT

¹⁸F-Fluciclovine is a novel PET/CT tracer. This blinded image evaluation (BIE) sought to demonstrate that, after limited training, readers naïve to ¹⁸F-fluciclovine could interpret ¹⁸F-fluciclovine images from subjects with biochemically recurrent prostate cancer with acceptable diagnostic performance and reproducibility. The primary objectives were to establish individual readers' diagnostic performance and the overall interpretation (2/3 reader concordance) compared with standard-of-truth data (histopathology or clinical follow-up) and to evaluate interreader reproducibility. Secondary objectives included comparison to the expert reader and assessment of intrareader reproducibility. Methods:¹⁸F-Fluciclovine PET/CT images (n = 121) and corresponding standard-of-truth data were collected from 110 subjects at Emory University using a single-time-point static acquisition starting 5 min after injection of approximately 370 MBq of ¹⁸F-fluciclovine. Three readers were trained using standardized interpretation methodology and subsequently evaluated the images in a blinded manner. Analyses were conducted at the lesion, region (prostate, including bed and seminal vesicle, or extraprostatic, including all lymph nodes, bone, or soft-tissue metastasis), and subject level. Results: Lesion-level overall positive predictive value was 70.5%. The readers' positive predictive value and negative predictive value were broadly consistent with each other and with the onsite read. Sensitivity was highest for readers 1 and 2 (68.5% and 63.9%, respectively) whereas specificity was highest for reader 3 (83.6%). Overall, prostate-level sensitivity was high (91.4%), but specificity was moderate (48.7%). Interreader agreement was 94.7%, 74.4%, and 70.3% for the lesion, prostate, and extraprostatic levels, respectively, with associated Fleiss' κ-values of 0.54, 0.50, and 0.57. Intrareader agreement was 97.8%, 96.9%, and 99.1% at the lesion level; 100%, 100%, and 91.7% in the prostate region; and 83.3%, 75.0%, and 83.3% in the extraprostatic region for readers 1, 2, and 3, respectively. Concordance between the BIE and the onsite reader exceeded 75% for each reader at the lesion, region, and subject levels. Conclusion: Specific training in the use of standardized interpretation methodology for assessment of ¹⁸F-fluciclovine PET/CT images enables naïve readers to achieve acceptable diagnostic performance and reproducibility when staging recurrent prostate cancer.

A kiloparsec-scale internal shock collision in the jet of a nearby radio galaxy

Jets of highly energized plasma with relativistic velocities are associated with black holes ranging in mass from a few times that of the Sun to the billion-solar-mass black holes at the centres of galaxies. A popular but unconfirmed hypothesis to explain how the plasma is energized is the 'internal shock model', in which the relativistic flow is unsteady. Faster components in the jet catch up to and collide with slower ones, leading to internal shocks that accelerate particles and generate magnetic fields. This mechanism can explain the variable, high-energy emission from a diverse set of objects, with the best indirect evidence being the unseen fast relativistic flow inferred to energize slower components in X-ray binary jets. Mapping of the kinematic profiles in resolved jets has revealed precessing and helical patterns in X-ray binaries, apparent superluminal motions, and the ejection of knots (bright components) from standing shocks in the jets of active galaxies. Observations revealing the structure and evolution of an internal shock in action have, however, remained elusive, hindering measurement of the physical parameters and ultimate efficiency of the mechanism. Here we report observations of a collision between two knots in the jet of nearby radio galaxy 3C 264. A bright knot with an apparent speed of (7.0 ± 0.8)c, where c is the speed of light in a vacuum, is in the incipient stages of a collision with a slower-moving knot of speed (1.8 ± 0.5)c just downstream, resulting in brightening of both knots--as seen in the most recent epoch of imaging.

The Open Connectome Project Data Cluster: Scalable Analysis and Vision for High-Throughput Neuroscience

We describe a scalable database cluster for the spatial analysis and annotation of high-throughput brain imaging data, initially for 3-d electron microscopy image stacks, but for time-series and multi-channel data as well. The system was designed primarily for workloads that build connectomes- neural connectivity maps of the brain-using the parallel execution of computer vision algorithms on high-performance compute clusters. These services and open-science data sets are publicly available at openconnecto.me. The system design inherits much from NoSQL scale-out and data-intensive computing architectures. We distribute data to cluster nodes by partitioning a spatial index. We direct I/O to different systems-reads to parallel disk arrays and writes to solid-state storage-to avoid I/O interference and maximize throughput. All programming interfaces are RESTful Web services, which are simple and stateless, improving scalability and usability. We include a performance evaluation of the production system, highlighting the effec-tiveness of spatial data organization.

STUDIES ON THE FLEXNER GROUP OF DYSENTERY BACILLI : I. THE SPECIFIC ANTIGENS OF SHIGELLA PARADYSENTERIAE (FLEXNER)

1. Methods for the isolation of the specific antigens of Types V, W, Z, and Newcastle Shigella paradysenteriae are given. 2. The physical, chemical, toxic, and immunological properties of these substances are described.

STUDIES ON THE FLEXNER GROUP OF DYSENTERY BACILLI : II. THE CHEMICAL DEGRADATION OF THE SPECIFIC ANTIGEN OF TYPE Z SHIGELLA PARADYSENTERIAE (FLEXNER)

The chemical and enzymatic dissociation of the specific antigen of Type Z Shigella paradysenteriae has been studied. The chemical, toxic, and serological properties of the products of degradation have been investigated. The nature of the toxic component has been discussed.

STUDIES ON THE FLEXNER GROUP OF DYSENTERY BACILLI : III. ANTIBODY RESPONSE IN MAN FOLLOWING THE ADMINISTRATION OF THE SPECIFIC ANTIGEN OF TYPE V SHIGELLA PARADYSENTERIAE (FLEXNER)

1. Volunteers have been immunized with the purified specific antigen of Type V Shigella paradysenteriae (Flexner). The subjects developed a high titer of bacterial agglutinins and mouse-protective antibodies. The agglutinin titer fell moderately after a period of 6 months. The subjects responded fairly well to a small recall dose of the antigen. 2. Two individuals from a group of 10 injected with the specific polysaccharide obtained from Type V organisms responded with an increase in bacterial agglutinins. Mouse-protective antibodies were demonstrable in the one serum tested.

AN IMMUNOLOGICAL AND ELECTROPHORETIC COMPARISON OF THE ANTIBODY TO C POLYSACCHARIDE AND THE C-REACTIVE PROTEIN OF ACUTE PHASE SERUM

1. Studies of the precipitation reaction of C polysaccharide with C protein, and of C polysaccharide with C antibody are reported. The similarity between these two systems in this respect is demonstrated. 2. The differences between C protein and C antibody are emphasized. The differences between this protein and antibodies in general have been reported previously by others. 3. Electrophoretic studies show that C antibody is in the gamma globulin fraction of serum whereas C protein migrates with the alpha₁ globulin fraction of acute phase protein.

Use of radionuclide bone scans in multicenter clinical trials: Opportunities for quality improvement

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Background: Radionuclide bone scans are widely utilized to screen for osseous metastases given their high sensitivity for detection of metastatic disease. However, the variance in image quality can significantly impact the diagnostic interpretation. Methods: Prospective assessment of image quality on 478 digital and hard copy planar bone scans received as part of several multi-center clinical trials was completed using a two reviewer paradigm. To improve image quality, the following steps were taken: an Internal Image Quality Task Committee was formed, a comprehensive training program for all internal quality control reviewers was completed, and a site qualification process was initiated prior to site selection and/or subject enrollment with direct feedback to the sites. Results: Significant image quality issues potentially limiting the diagnostic interpretation of the radionuclide scans were initially identified in 21% of the submitted radionuclide bone scans. Quality issues were based on: technical factors, poor imaging technique, and subject factors which could not be corrected. A discordance rate of 4.3% among the two reviewers was also measured. After institution of the above steps, the net result was a 58% decrease in the quality control issues that were previously identified. The most significant improvements occurred on the basis of the site qualification process where sites changed from sending hard copy to digital images and there was direct feedback from the Imaging Core Lab to the sites to correct identified issues. Conclusions: Image quality of bone scans in multicenter clinical trials can be improved with direct communication coupled with a site qualification process prior to subject enrollment. We suspect these quality improvements will impact event driven endpoints that rely on the accurate assessment of bone lesions. We further suspect this level of quality control will continue to increase in importance as technology evolves to include hybrid scanning techniques such as SPECT/CT. This parallels our experience in the level of quality control and site qualification required for deployment of FDG-PET imaging in multicenter clinical trials.

[Table: see text]

Patient weight and event-free survival for children under 2 years of age at diagnosis with favorable histology Wilms tumor

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Background: Over- and underweight have been associated with excess mortality in certain childhood cancers. The impact of the child’s weight at diagnosis on event-free survival (EFS) in favorable histology Wilms tumor (FH WT) is unknown. Methods: Patients with FH WT under 2 years of age at enrolment on NWTS-5 were included. This age group was analyzed by body weight in kilograms because body mass index (BMI) norms do not exist for individuals less than 2 years old. Outcomes by BMI for children older than 2 years of age with FH WT will be analyzed separately. CDC 2000 growth charts were used. Patients were stratified for risk based on stage and chemotherapy protocol [EE4A = vincristine/dactinomycin] [DD4A = vincristine/doxorubicin/ actinomycin]. A univariate analysis of the relationship of weight-for-age and EFS was calculated. A Cox proportional hazards model was fitted for EFS examining four subsets of weight-for-age by percentiles: a) less than 5%, b) 5–9.9%, c) 90–94.9% and d) more than 95% and adjusting for risk/treatment groups via stratification. Results: 594 patients met the study criteria. 567 had weights recorded. Median follow-up was 4.7 years. 10% of patients had a weight for age percentile of 5.6 or below and 10% had a weight percentile of 94.1 or above. A univariate analysis of the relationship of weight-for-age and EFS showed no relationship (p=0.40, log-rank test). A Cox proportional hazards model, stratified by risk/treatment groups, showed that low or high weight-for-age was not predictive of outcome (p=0.24). Conclusions: There was no evidence that low or high weight-for-age was predictive for EFS among patients less than 2 years old with FH WT. There were more patients with lower or higher weight than would be expected.

[Table: see text]

No significant financial relationships to disclose.

[Kidney tumors in childhood]

Types of renal tumors arising in children are different from those occurring in adults. Nephroblastoma is the most common (85%) with a clinical outcome which has dramatically improved in the last 30 years. Current classifications are aimed at better adaptation of treatment to each individual case, reducing iatrogenic complications without impairing total cure. Amongst entities which have been recently described or are better known we can find juvenile carcinoma associated with Xp11.2 translocation, renal medullary carcinoma, metanephric tumors, etc. Role of molecular cytogenetics is increasing for classification (and treatment) and this should always be kept in mind when dealing a fresh specimen of childhood renal tumor.

Metanephric stromal tumor: a rare benign pediatric renal mass

We report a rare case and description of a benign pediatric renal mass. To our knowledge, this tumor has never been described in urologic published reports. It is possible that the identification of this renal tumor could spare a child the toxic adjuvant chemotherapy that would be administered if confused with histologically similar tumors such as clear cell sarcoma of the kidney.

Treatment with nephrectomy only for small, stage I/favorable histology Wilms' tumor: a report from the National Wilms' Tumor Study Group

PURPOSE

Children younger than 24 months with small (< 550 g), favorable histology (FH) Wilms tumors (WTs) were shown in a pilot study to have an excellent prognosis when treated with nephrectomy only.

PATIENTS AND METHODS

A study of nephrectomy only for the treatment of selected children with FH WT was undertaken. Stringent stopping rules were designed to insure closure of the study if the true 2-year relapse-free survival rate was 90% or lower.

RESULTS

Seventy-five previously untreated children younger than 24 months with stage I/FH WTs for which the surgical specimen weighed less than 550 g were treated with nephrectomy only. Three patients developed metachronous, contralateral WT 1.1, 1.4, and 2.3 years after nephrectomy, and eight patients relapsed 0.3 to 1.05 years after diagnosis (median, 0.4 years; mean, 0.51 years). The sites of relapse were lung (n = 5) and operative bed (n = 3). The 2-year disease-free (relapse and metachronous contralateral WT) survival rate was 86.5%. The 2-year survival rate is 100% with a median follow-up of 2.84 years. The 2-year disease-free survival rate (excluding metachronous contralateral WT) was 89.2%, and the 2-year cumulative risk of metachronous contralateral WT was 3.1%.

CONCLUSION

Children younger than 24 months treated with nephrectomy only for a stage I/FH WT that weighed less than 550 g had a risk of relapse, including the development of metachronous contralateral WT, of 13.5% 2 years after diagnosis. All patients who experienced relapse on this trial are alive at this time. This approach will be re-evaluated in a clinical trial using a less conservative stopping rule.

ALK1 and p80 expression and chromosomal rearrangements involving 2p23 in inflammatory myofibroblastic tumor

BACKGROUND

Inflammatory myofibroblastic tumor (IMT) is an uncommon tumor of extrapulmonary and pulmonary tissues with an unpredictable clinical course, occasional recurrences, and rare malignant transformation. Clonal abnormalities with rearrangements of chromosome of 2p23 and the ALK gene have been reported in a few cases. The purpose of this study is to investigate whether these are consistent abnormalities among IMTs or represent a distinct subset.

DESIGN

Formalin-fixed, paraffin-embedded archival tissue sections from 47 IMTs in 40 patients were immunostained with monoclonal antibodies against ALK and p80. Fluorescence in situ hybridization for ALK rearrangements was done on 22 IMTs from 19 patients. Findings were correlated with clinical features and outcome.

RESULTS

ALK positivity was observed in 17 of 47 IMTs (36%) and p80 positivity in 16 of 47 IMTs (34%). Fluorescence in situ hybridization showed ALK rearrangements in nine cases (47%), aneuploidy in three cases (16%), and no rearrangement in seven cases (37%). IMTs with ALK abnormalities by immunohistochemistry and/or fluorescence in situ hybridization originated in the abdomen/pelvis/retroperitoneum, chest, and extremities. The mean age was 6.6 years, with a male/female ratio of 1.3. 64% of patients had no evidence of disease at last follow-up, 45% had one or more recurrences, and 18% displayed histologic evidence of malignant transformation. The IMTs without ALK abnormalities occurred in older children, were more frequent in females, and had fewer recurrences. However, in this group of 40 patients, the differences between the groups with and without ALK abnormalities did not have statistical significance. Aneuploidy without ALK abnormalities was associated with malignant transformation in three of five cases.

CONCLUSIONS

Abnormalities of ALK and p80 and evidence of chromosomal rearrangements of 2p23 occur in a significant proportion of IMTs. These changes are most frequent in abdominal and pulmonary IMTs in the first decade of life and are associated with a higher frequency of recurrence. These findings confirm the neoplastic nature of a subset IMT with ALK abnormalities and suggest that aneuploid IMT is a subset with more aggressive clinical behavior.

Non-mosaic trisomy 20 presenting at 21 weeks' gestation as a thoraco-abdominal mass

Non-mosaic trisomy 20 is rare in fetuses surviving beyond the first trimester. We report a case of a fetus with non-mosaic trisomy 20 in amniotic fluid cultures obtained during the prenatal evaluation of an unusual thoraco-abdominal mass which was found at autopsy to be pulmonary sequestration. Gross inspection and autopsy of the fetus revealed multiple anomalies.

Astronomical constraints on the cosmic evolution of the fine structure constant and possible quantum dimensions

We present measurements of absorption by the 21 cm hyperfine transition of neutral hydrogen toward radio sources at substantial look-back times. These data are used in combination with observations of rotational transitions of common interstellar molecules to set limits on the evolution of the fine structure constant: alpha/ alpha<3.5x10(-15) yr(-1), to a look-back time of 4.8 Gyr. In the context of string theory, the limit on the secular evolution of the scale factor of the compact dimensions, R, is &Rdot/ R<10(-15) yr(-1). Including terrestrial and other astronomical measurements places 2sigma limits on slow oscillations of R from the present to the epoch of cosmic nucleosynthesis, just seconds after the big bang, of DeltaR /R<10(-5).

Coexpression of hypoxia-inducible factor 1-alpha and vascular endothelial growth factor in Wilms' tumor

BACKGROUND/PURPOSE

Hypoxia-inducible factor 1 alpha (HIF-1alpha) is an important transcriptional factor responsible for regulating expression of the angiogenic cytokine, vascular endothelial growth factor (VEGF). Little information is available regarding factors involved in the hypoxic cascade, such as HIF or VEGF in Wilms' tumor. We concomitantly evaluate the expression of HIF-1alpha and VEGF in ex vivo human Wilms' tumor specimens.

METHODS

Immunohistochemical analysis (IHC) utilizing a monoclonal human anti-HIF-1alpha or a polyclonal anti-VEGF antibody was performed on ex vivo specimens of Wilms' tumor (n = 18). Predominant tumor histologic subtype was divided equally between epithelial (n = 6), blastemal (n = 6), and mixed (n = 6). Specimens were scored on a predetermined scale for distribution (percent positive cells) and intensity of HIF-1alpha/VEGF expression within areas of tumor.

RESULTS

IHC analysis found that HIF-1alpha and VEGF were expressed in all Wilms' tumor specimens. Strong nuclear staining for HIF-1alpha was seen in all samples evaluated, (n = 18), mean score 2.7 (>50% cells exhibiting nuclear HIF-1alpha expression). Cytoplasmic staining for HIF-1alpha also was seen in 15 of 18 samples (83%). Distribution of VEGF was equivalent between blastemal and epthelial components, mean score 2.23 versus 2.35.

CONCLUSIONS

HIF-1alpha and one of its regulatory end-products, the angiogenic cytokine VEGF, are simultaneously expressed in human Wilms' tumor. In Wilms' tumor, intratumoral hypoxia may stimulate tumor conversion to the angiogenic phenotype and incite production of VEGF. Strategies targeting the hypoxic cascade ultimately may prove efficacious against Wilms' tumor.

Genomic aberrations in human hepatocellular carcinomas of differing etiologies

We sought to assess whether genetic abnormalities in hepatocellular carcinoma differed in geographic locations associated with different risk factors. Comparative genomic hybridization (CGH) was applied to the genome-wide chromosomal analysis in 83 tumor samples from four different geographic origins. Samples were obtained from regions that differed in aflatoxin exposure: China (Hong Kong with low aflatoxin exposure and Shanghai with moderate aflatoxin exposure), Japan, and the United States (negligible aflatoxin exposure). Cases from Hong Kong and Shanghai were all hepatitis B virus (HBV) related, those from Japan were hepatitis C virus related, and those from the United States were HBV negative. In parallel, the mutational pattern of the whole p53 gene (exons 1-11) was also investigated in these cases. CGH revealed a complex pattern of chromosomal gains and losses, with the commonest aberration in each geographic location being chromosome 1q copy number gain (38-60%). Shanghai cases displayed the highest number of total aberrations per sample, with significant copy losses on 4q (75%), 8p (70%), and 16q (65%). Hepatitis C virus-related samples from Japan had a characteristically high incidence of 11q13 gain. p53 mutation(s) was detected in 23% of Hong Kong cases, 40% of Shanghai, 31% of Japan, but only 6% of the United States cases. The "aflatoxin-associated" codon 249 mutation was, however, identified only in samples from China (13% Hong Kong and 20% Shanghai). This finding, together with the highly aberrant pattern of genetic changes detected in the Shanghai series, is suggestive of the genotoxic effects of aflatoxin being more broadly based. It is also likely that there is a synergistic effect of HBV infection and high aflatoxin exposure in promoting hepatocellular carcinoma development. It appears from our CGH study that individual risk factors are indeed associated with distinct genetic aberrations, although changes in 1q gain appear common to all.

Myogenin is a specific marker for rhabdomyosarcoma: an immunohistochemical study in paraffin-embedded tissues

Myogenin belongs to a group of myogenic regulatory proteins whose expression determines commitment and differentiation of primitive mesenchymal cells into skeletal muscle. The expression of myogenin has been demonstrated to be extremely specific for rhabdomyoblastic differentiation, which makes it a useful marker in the differential diagnosis of rhabdomyosarcomas (RMS) from other malignant small round cell tumors of childhood. Commercially available antibodies capable of detecting myogenin in routinely processed formalin-fixed paraffin-embedded (FFPE) tissue are now available. In this study, we evaluated myogenin expression using the monoclonal myf-4 antibody (Novocastra Labs) on FFPE in a large number of pediatric tumors in order to define the clinical utility of this marker. A total of 119 tumors were studied. These included 48 alveolar RMS (ARMS), 20 embryonal RMS (ERMS), one spindle cell RMS, 16 Ewing's sarcomas (ES), six nephroblastomas, two ectomesenchymomas, seven precursor hematopoietic neoplasms, five olfactory neuroblastomas, three neuroblastomas, six desmoplastic small round cell tumors, and five rhabdoid tumors. Distinct nuclear staining for myogenin was noted in all 69 RMS. Notably, the number of positive tumor cells differed between the ARMS and ERMS. In ARMS, the majority of tumor cells (75 to 100%) were positive, in contrast to ERMS, in which the positivity ranged from rare + to 25% in all but three tumors. Additionally, myogenin positivity was seen in two of two ectomesenchymomas and in two nephroblastomas with myogenous differentiation. All other tumors were clearly negative. Our results indicate that staining for myogenin is an extremely reliable and specific marker for rhabdomyoblastic differentiation. It gives consistent and easily interpretable results in routinely fixed tissues.

Absence of EWS/FLI1 fusion in olfactory neuroblastomas indicates these tumors do not belong to the Ewing's sarcoma family

The balanced reciprocal translocation t(11;22)(q24;q12) is a specific molecular marker for the Ewing's sarcoma family of tumors (ESFT). Based on the detection of this translocation in some olfactory neuroblastomas (ONBs), it has been proposed that ONBs also belong to the ESFT. Others have challenged this hypothesis; however, the rarity of ONBs, as well as the lack of molecular techniques that work reliably on formalin fixed tissue, have precluded the molecular analysis of a significant number of cases. We evaluated the immunophenotypic and molecular features of 17 paranasal small round neuroectodermal tumors using routinely fixed tissue. Probes localizing to 22q12 (EWS) and 11q24 (FLI-1) were used in a standard 2-color fluorescence in situ hybridization (FISH) assay to evaluate EWS/FLI1 fusion on the der(22). Sixteen tumors were mic-2 negative, whereas 1 tumor was mic-2 positive, compatible with ONB and ESFT, respectively. Thirteen of 15 ONBs could be evaluated by FISH, and all 13 were negative for the EWS/FLI1 fusion. Distinct fusion signals were identified in the single paranasal ESFT. Our findings indicate that ONBs lack the EWS/FLI1 fusion and are unrelated to the ESFT; however, true ESFTs may rarely occur as primary sinonasal tumors.

Neural innervation of the newborn exstrophic bladder: an immunohistochemical study

PURPOSE

Continence in bladder exstrophy is not always easy to attain. Some patients have a small noncontractile bladder while in others an adequate capacity bladder may not contract normally. Innervation of the detrusor determines its ability to contract. The exstrophic bladder during organogenesis does not store urine. Therefore, its requirements for contraction are limited and its innervation would potentially reflect this difference in function. The availability of specific immunostains allows better differentiation of the neural elements in tissue specimens. Our study focuses on myelinated nerves innervating the newborn exstrophic detrusor.

MATERIALS AND METHODS

Biopsies were obtained from the anterior wall of 10 newborn exstrophic bladders at the time of initial closure and compared to 10 newborn controls. Patient age at bladder closure ranged from 1 to 90 days (mean 22). Specimens were formalin fixed and paraffin embedded. Then 4 micro. thick sections were stained with S100, an immunostain that stains neural crest elements including Schwann's elements (myelinated nerve fibers). The entire tissue section was examined. Microscopic fields were sequentially examined with a morphometric system comprising a microscope, video camera and personal computer with a video frame grabber. The output image was displayed on a second monitor and the nerves in each field and numbers of fields in each section were counted. To be considered, fields had to have greater than 75% tissue coverage. The average number of nerves per field was compared between the exstrophic bladders and normal controls.

RESULTS

The average number of myelinated nerves per field in the newborn exstrophic bladders (0.13 per field) was significantly reduced compared to normal controls (1.25 per field) and statistically significant (p<0.001). This reduction in nerve fibers appeared to be due to lack of smaller fibers with preservation of larger fibers. There was no difference in innervation in cases closed at birth compared to those closed after month 1 of life.

CONCLUSIONS

The newborn exstrophic bladder has fewer myelinated nerve fibers than normal controls primarily due to reduction in the smaller fibers which may represent a maturational delay in the development of the exstrophic bladder. Another possible explanation may be degeneration of the fibers due to lack of bladder contraction but no indication of nerve degeneration was evident in our study. Followup studies of patients at various stages of reconstruction will determine the evolution of neural innervation in the exstrophic bladder.

Gonadal morphology in cloacal exstrophy: implications in gender assignment

OBJECTIVE

To compare the histology of gonads excised from males with cloacal exstrophy (the most severe variant of the exstrophy-epispadias complex) undergoing early gonadectomy and gender reassignment (to obviate difficulties in reconstructing male external genitalia) with those published previously.

PATIENTS AND METHODS

Testicular tissue was obtained from males with cloacal exstrophy undergoing gender reassignment shortly after birth. Slides were stained for histological evaluation and reviewed by one author. The histology was compared with known normal features for newborn testicular tissue. The mean age at the time of gender reassignment was 6 months.

RESULTS

There were no significant abnormalities in the architecture of the rete testis, epididymis or vas of the study specimens. There were more germ cells in some patients with cloacal exstrophy, but this finding was not specific and is of unknown clinical significance.

CONCLUSIONS

Despite the severity of the malformations in cloacal exstrophy, testicular histology is preserved. In highly selected genotypic males who have adequate phallic structures, congruent gender assignment is appropriate and early orchidopexy is recommended.

Congenital cystic adenomatoid malformation of the lung: insights into the pathogenesis utilizing quantitative analysis of vascular marker CD34 (QBEND-10) and cell proliferation marker MIB-1

Congenital cystic adenomatoid malformation (CCAM) encompasses a spectrum of variably cystic developmental anomalies of the lung histologically characterized by immature lung tissue. The pathogenesis is uncertain, but many investigators favor a maturation arrest in bronchopulmonary development. To investigate this hypothesis, the vascular development and proliferation capacity of lung tissue with CCAM type I from nine infants ranging in age from 20 weeks gestation to 42 days old were studied immunohistochemically utilizing CD34 for the former and MIB-1 for the latter. Both markers were quantitated on an image analysis system. CCAM was hypovascular with a mean vascular index of 20.05% +/- 6.58 compared to 40.06% +/- 4.19 for the age-matched controls (P < 0.000001). The proliferation index of both epithelial and mesenchymal components was higher in CCAM (10.46 +/- 3.48) than in control tissue (7.14 +/- 1.88; P < 0.012). In contrast to the control lung tissue which showed a remarkable synchrony between the vascular development and proliferation throughout the parenchyma, focal asynchrony between the proliferation of the epithelial and stromal components was noted in CCAM. The vascularity in CCAM corresponds to that seen in early gestation. The cellular proliferation in CCAM is higher than in full-term infants and corresponds to late second trimester or early third trimester fetuses. These findings support the proposed pathogenesis of a maturation defect in lung embryogenesis.

Cytogenetic abnormalities in two cases of neuroblastoma

Neuroblastomas are common solid tumors in children. We report chromosome analysis of two neuroblastomas, each studied at diagnosis and at recurrence. The first case was a clinical stage D tumor which showed 45,X-Y, add(1)(p34),der(15)t(Y;15)(q11;p13), and double minutes on cytogenetic analysis at diagnosis. At recurrence, the same structural abnormalities were present along with a homogeneously staining region (hsr) at 8q22, 19p12, or 3p23 in each of three related clones. The hsr were shown to represent amplification of the N-myc gene by in situ hybridization. Cytogenetic analysis of the second tumor, stage D-S, showed 48-54,XX,der(1)add (1)(q41), +2, +7, +7, inv(9), +17, + mar. The lack of demonstrative involvement of 1p or visible evidence of gene amplification has also characterized the limited number of D-S specimens previously described, suggesting that stage D-S neuroblastoma indeed differs from stage D disease at the genetic level.

Bladder wall abnormalities in myelodysplastic bladders: a computer assisted morphometric analysis

Myelodysplasia represents the most common cause of neurogenic bladder dysfunction in children. The specific histological features associated with myelodysplastic bladders have not been previously characterized. Our objective was to study the relationship between smooth muscle and connective tissue in control and myelodysplastic bladders using classical morphometric analysis with the assistance of an automated image analysis system. Gross histological analysis of the bladder specimens of normal stillborn fetuses showed organized muscle bundles embedded in a small amount of connective tissue. The bladder specimens of myelomeningocele stillborn fetuses showed a marked paucity of muscle bundles as well as a significantly diminished size of the muscle bundles. The myelomeningocele bladder specimens obtained from patients undergoing autopsy and those undergoing augmentation cystoplasty revealed significant interfascicular and pericellular infiltration of the smooth muscle by dense connective tissue. Quantitative morphometric analysis showed that the myelomeningocele stillborn fetuses have a significant increase in the volumetric content of connective tissue compared to control stillborn fetuses. The bladders of myelomeningocele patients who underwent autopsy or augmentation cystoplasty had a 3-fold increase in connective tissue when compared to normal controls. These findings reveal that structural changes in the histological components of the myelodysplastic bladder can be demonstrated not only in patients of varying ages undergoing autopsy or augmentation cystoplasty but also in the developing fetus. These findings enhance our understanding of the relationship of connective tissue proliferation to smooth muscle in the myelodysplastic bladder. We discuss the relationship of these findings to pathological detrusor morphology and detrusor dysfunction.

Selenium deficiency and cardiomyopathy in acquired immunodeficiency syndrome

Selenium deficiency is common in patients with human immunodeficiency virus infection and may contribute to the development of cardiomyopathy. A 5-year-old boy with congenital human immunodeficiency virus infection developed cardiomyopathy. Evaluation for reversible causes of cardiomyopathy was notable for the diagnosis of selenium deficiency. Cardiac function improved on selenium supplementation. The role of selenium in cardiac dysfunction and the need for nutritional evaluation and supplementation of malnourished patients with acquired immunodeficiency syndrome is discussed.

Stand by...you're on! Physiotherapy on community television

A 12-month trial of a community television series entitled Physiotherapy and Your Health has been completed. The evolution and philosophy of the series are described. Mechanics of production, limitations, and potential scope for other television series on physiotherapy, in areas served by community television outlets, are presented.

Sebaceous gland carcinoma of the eyelid

We diagnosed sebaceous gland carcinoma of the right lower eyelid in an 82-year-old man. Computed tomography showed the lesion extending from the eyelids anteriorly to the optic foramen posteriorly. With this orbital neoplasm, was an occlusion of the central retinal artery in his right eye. The right orbit was removed surgically and biopsy of the optic foramen region indicated malignant cells. Localized radiation to the right orbit was then initiated postoperatively.