Facioscapulohumeral dystrophy: incomplete suppression of a retrotransposed gene

Each unit of the D4Z4 macrosatellite repeat contains a retrotransposed gene encoding the DUX4 double-homeobox transcription factor. Facioscapulohumeral dystrophy (FSHD) is caused by deletion of a subset of the D4Z4 units in the subtelomeric region of chromosome 4. Although it has been reported that the deletion of D4Z4 units induces the pathological expression of DUX4 mRNA, the association of DUX4 mRNA expression with FSHD has not been rigorously investigated, nor has any human tissue been identified that normally expresses DUX4 mRNA or protein. We show that FSHD muscle expresses a different splice form of DUX4 mRNA compared to control muscle. Control muscle produces low amounts of a splice form of DUX4 encoding only the amino-terminal portion of DUX4. FSHD muscle produces low amounts of a DUX4 mRNA that encodes the full-length DUX4 protein. The low abundance of full-length DUX4 mRNA in FSHD muscle cells represents a small subset of nuclei producing a relatively high abundance of DUX4 mRNA and protein. In contrast to control skeletal muscle and most other somatic tissues, full-length DUX4 transcript and protein is expressed at relatively abundant levels in human testis, most likely in the germ-line cells. Induced pluripotent (iPS) cells also express full-length DUX4 and differentiation of control iPS cells to embryoid bodies suppresses expression of full-length DUX4, whereas expression of full-length DUX4 persists in differentiated FSHD iPS cells. Together, these findings indicate that full-length DUX4 is normally expressed at specific developmental stages and is suppressed in most somatic tissues. The contraction of the D4Z4 repeat in FSHD results in a less efficient suppression of the full-length DUX4 mRNA in skeletal muscle cells. Therefore, FSHD represents the first human disease to be associated with the incomplete developmental silencing of a retrogene array normally expressed early in development.

Perinatal transmission of the human immunodeficiency virus type 1 to infants of seropositive women in Zaire

To examine perinatal transmission of the human immunodeficiency virus type 1 (HIV-1) in Zaire, we screened 8108 women who gave birth at one of two Kinshasa hospitals that serve populations of markedly different socioeconomic status. For up to one year, we followed the 475 infants of the 466 seropositive women (5.8 percent of those screened) and the 616 infants of 606 seronegative women matched for age, parity, and hospital. On the basis of clinical criteria, 85 of the seropositive women (18 percent) had the acquired immunodeficiency syndrome (AIDS). The infants of seropositive mothers, as compared with those of seronegative mothers, were more frequently premature, had lower birth weights, and had a higher death rate in the first 28 days (6.2 vs. 1.2 percent; P less than 0.0001). The patterns were similar at the two hospitals. Twenty-one percent of the cultures for HIV-1 of 92 randomly selected cord-blood samples from infants of seropositive women were positive. T4-cell counts were performed in 37 seropositive women, and cord blood from their infants was cultured. The cultures were positive in the infants of 6 of the 18 women with antepartum T4 counts of 400 or fewer cells per cubic millimeter, as compared with none of the infants of the 19 women with more than 400 T4 cells per cubic millimeter (P = 0.02). One year later, 21 percent of the infants of the seropositive mothers had died as compared with 3.8 percent of the control infants (P less than 0.001), and 7.9 percent of their surviving infants had AIDS. We conclude that the mortality rates among children of seropositive mothers are high regardless of socioeconomic status, and that perinatal transmission of HIV-1 has a major adverse effect on infant survival in Kinshasa.

Juvenile localized scleroderma: clinical and epidemiological features in 750 children. An international study

OBJECTIVE

Juvenile localized scleroderma (JLS) includes a number of conditions often grouped together. With the long-term goal of developing uniform classification criteria, we studied the epidemiological, clinical and immunological features of children with JLS followed by paediatric rheumatology and dermatology centres.

METHODS

A large, multicentre, multinational study was conducted by collecting information on the demographics, family history, triggering environmental factors, clinical and laboratory features, and treatment of patients with JLS.

RESULTS

Seven hundred and fifty patients with JLS from 70 centres were enrolled into the study. The disease duration at diagnosis was 18 months. Linear scleroderma (LS) was the most frequent subtype (65%), followed by plaque morphea (PM) (26%), generalized morphea (GM) (7%) and deep morphea (DM) (2%). As many as 15% of patients had a mixed subtype. Ninety-one patients (12%) had a positive family history for rheumatic or autoimmune diseases; 100 (13.3%) reported environmental events as possible trigger. ANA was positive in 42.3% of the patients, with a higher prevalence in the LS-DM subtype than in the PM-GM subtype. Scl70 was detected in the sera of 3% of the patients, anticentromere antibody in 2%, anti-double-stranded DNA in 4%, anti-cardiolipin antibody in 13% and rheumatoid factor in 16%. Methotrexate was the drug most frequently used, especially during the last 5 yr.

CONCLUSION

This study represents the largest collection of patients with JLS ever reported. The insidious onset of the disease, the delay in diagnosis, the recognition of mixed subtype and the better definition of the other subtypes should influence our efforts in educating trainees and practitioners and help in developing a comprehensive classification system for this syndrome.

Classification of morphea (localized scleroderma)

OBJECTIVE

To classify and describe morphea (localized scleroderma).

DESIGN

A review of morphea and its subtypes is presented.

RESULTS

The current classification of morphea is incomplete and confusing. As knowledge of the spectrum of disease continues to evolve, the controversy and confusing nature of its multiple subtypes present a challenge for the physician who encounters a patient with this condition. Thus, we propose that morphea be classified into the following five groups: plaque, generalized, bullous, linear, and deep. This classification, based on clinical morphologic findings, will simplify the diagnostic and therapeutic approach.

CONCLUSION

Morphea represents a wide variety of clinical entities that seen to be on the opposite end of the scleroderma spectrum from systemic sclerosis. The cutaneous lesions eventually evolve from a sclerotic stage to a nonindurated stage, and residual hypopigmentation or hyperpigmentation follows. The histologic pattern in patients with morphea is similar to that in patients with progressive systemic sclerosis. Although treatment is nonstandardized, hydroxychloroquine sulfate may be beneficial.

Replication of HIV-1 in dendritic cell-derived syncytia at the mucosal surface of the adenoid

Human immunodeficiency virus-type 1 (HIV-1) replicates actively in infected individuals, yet cells with intracellular depots of viral protein are observed only infrequently. Many cells expressing the HIV-1 Gag protein were detected at the surface of the nasopharyngeal tonsil or adenoid. This infected mucosal surface contained T cells and dendritic cells, two cell types that together support HIV-1 replication in culture. The infected cells were multinucleated syncytia and expressed the S100 and p55 dendritic cell markers. Eleven of the 13 specimens analyzed were from donors who did not have symptoms of acquired immunodeficiency syndrome (AIDS). The interaction of dendritic cells and T cells in mucosa may support HIV-1 replication, even in subclinical stages of infection.

MicroRNA discovery and profiling in human embryonic stem cells by deep sequencing of small RNA libraries

We used massively parallel pyrosequencing to discover and characterize microRNAs (miRNAs) expressed in human embryonic stem cells (hESC). Sequencing of small RNA cDNA libraries derived from undifferentiated hESC and from isogenic differentiating cultures yielded a total of 425,505 high-quality sequence reads. A custom data analysis pipeline delineated expression profiles for 191 previously annotated miRNAs, 13 novel miRNAs, and 56 candidate miRNAs. Further characterization of a subset of the novel miRNAs in Dicer-knockdown hESC demonstrated Dicer-dependent expression, providing additional validation of our results. A set of 14 miRNAs (9 known and 5 novel) was noted to be expressed in undifferentiated hESC and then strongly downregulated with differentiation. Functional annotation analysis of predicted targets of these miRNAs and comparison with a null model using non-hESC-expressed miRNAs identified statistically enriched functional categories, including chromatin remodeling and lineage-specific differentiation annotations. Finally, integration of our data with genome-wide chromatin immunoprecipitation data on OCT4, SOX2, and NANOG binding sites implicates these transcription factors in the regulation of nine of the novel/candidate miRNAs identified here. Comparison of our results with those of recent deep sequencing studies in mouse and human ESC shows that most of the novel/candidate miRNAs found here were not identified in the other studies. The data indicate that hESC express a larger complement of miRNAs than previously appreciated, and they provide a resource for additional studies of miRNA regulation of hESC physiology. Disclosure of potential conflicts of interest is found at the end of this article.

Self-renewal of human embryonic stem cells requires insulin-like growth factor-1 receptor and ERBB2 receptor signaling

Despite progress in developing defined conditions for human embryonic stem cell (hESC) cultures, little is known about the cell-surface receptors that are activated under conditions supportive of hESC self-renewal. A simultaneous interrogation of 42 receptor tyrosine kinases (RTKs) in hESCs following stimulation with mouse embryonic fibroblast (MEF) conditioned medium (CM) revealed rapid and prominent tyrosine phosphorylation of insulin receptor (IR) and insulin-like growth factor-1 receptor (IGF1R); less prominent tyrosine phosphorylation of epidermal growth factor receptor (EGFR) family members, including ERBB2 and ERBB3; and trace phosphorylation of fibroblast growth factor receptors. Intense IGF1R and IR phosphorylation occurred in the absence of MEF conditioning (NCM) and was attributable to high concentrations of insulin in the proprietary KnockOut Serum Replacer (KSR). Inhibition of IGF1R using a blocking antibody or lentivirus-delivered shRNA reduced hESC self-renewal and promoted differentiation, while disruption of ERBB2 signaling with the selective inhibitor AG825 severely inhibited hESC proliferation and promoted apoptosis. A simple defined medium containing an IGF1 analog, heregulin-1beta (a ligand for ERBB2/ERBB3), fibroblast growth factor-2 (FGF2), and activin A supported long-term growth of multiple hESC lines. These studies identify previously unappreciated RTKs that support hESC proliferation and self-renewal, and provide a rationally designed medium for the growth and maintenance of pluripotent hESCs.

Fractures after rheumatoid arthritis. A population-based study

In a population-based study, the incidence of osteoporotic fractures in patients who have been diagnosed as having rheumatoid arthritis was investigated. This incidence was found to be increased, though not dramatically so: the relative risk for hip fracture, for example, was 1.5. Univariate analyses generally indicated increased risk associated with increasing age, earlier age at diagnosis of rheumatoid arthritis, disability, impaired ambulation, steroid use, and thinness, and decreased risk associated with obesity and estrogen use. In multivariate analyses, only aging, impaired ambulation, and thinness were identified as independent risk factors.

Cell autonomous regulation of multiple Dishevelled-dependent pathways by mammalian Nkd

Genetic studies have identified Drosophila Naked Cuticle (Nkd) as an antagonist of the canonical Wnt/beta-catenin signaling pathway, but its mechanism of action remains obscure [Zeng, W., Wharton, K. A., Jr., Mack, J. A., Wang, K., Gadbaw, M., et al. (2000) Nature (London) 403, 789--795]. Here we have cloned a cDNA encoding a mammalian homolog of Drosophila Nkd, mNkd, and demonstrated that mNkd interacts directly with Dishevelled. Dishevelled is an intracellular mediator of both the canonical Wnt pathway and planar cell polarity (PCP) pathway. Activation of the c-Jun-N-terminal kinase has been implicated in the PCP pathway. We showed that mNkd acts in a cell-autonomous manner not only to inhibit the canonical Wnt pathway but also to stimulate c-Jun-N-terminal kinase activity. Expression of mNkd disrupted convergent extension in Xenopus, consistent with a role for mNkd in the PCP pathway. These data suggest that mNkd may act as a switch to direct Dishevelled activity toward the PCP pathway, and away from the canonical Wnt pathway.

Psychosocial outcomes and health status of adults who have had juvenile rheumatoid arthritis: a controlled, population-based study

OBJECTIVE

The goal of this study was to evaluate the physical and psychosocial impact of juvenile rheumatoid arthritis (JRA) among a population-based cohort of adults who had the disease during childhood, compared with a control cohort of subjects with no history of JRA.

METHODS

The Rochester Epidemiology Project database was used to identify all cases of JRA (based on the American College of Rheumatology [formerly, the American Rheumatism Association] 1977 criteria) among Rochester, Minnesota residents first diagnosed between January 1, 1960 and December 31, 1993. Controls were age- and sex-matched to the cases as of the date of diagnosis of JRA. A pretested postal survey was mailed to all adult cases (whose date of birth was before December 31, 1975) and matched controls from the same population, to obtain information on socioeconomic issues and functional status (using the Health Assessment Questionnaire and the Health Status Questionnaire). The complete medical records of all cases and controls were reviewed to obtain information on demographics and clinical manifestations of JRA.

RESULTS

Of the 50 eligible cases, 44 (88%) responded to the survey. There were 102 age- and sex-matched controls (2-3 per case) who responded to the survey. Seventy-three percent of the cases had pauciarticular-onset JRA, 16% had polyarticular-onset JRA, and 11% had systemic-onset JRA. Average followup was 24.7 years and 24.5 years after the index date for cases and controls, respectively. Greater disability (P = 0.0002), more bodily pain (P = 0.0002), increased fatigue (P = 0.0112), poorer health perception (P = 0.0004), and decreased physical functioning (P = 0.0002) were reported by the cases compared with the controls. JRA cases reported significantly lower rates of employment (P = 0.015) and lower levels of exercise (P = 0.0002) than did controls. Level of educational achievement, annual income, health insurance status, and rate of pregnancy and childbirth were similar for both cases and controls.

CONCLUSION

Adults who have had JRA during childhood experience long-term physical and psychosocial impairment.

Histone deacetylase inhibition elicits an evolutionarily conserved self-renewal program in embryonic stem cells

Recent evidence indicates that mouse and human embryonic stem cells (ESCs) are fixed at different developmental stages, with the former positioned earlier. We show that a narrow concentration of the naturally occurring short-chain fatty acid, sodium butyrate, supports the extensive self-renewal of mouse and human ESCs, while promoting their convergence toward an intermediate stem cell state. In response to butyrate, human ESCs regress to an earlier developmental stage characterized by a gene expression profile resembling that of mouse ESCs, preventing precocious Xist expression while retaining the ability to form complex teratomas in vivo. Other histone deacetylase inhibitors (HDACi) also support human ESC self-renewal. Our results indicate that HDACi can promote ESC self-renewal across species, and demonstrate that ESCs can toggle between alternative states in response to environmental factors.

Definitive-like erythroid cells derived from human embryonic stem cells coexpress high levels of embryonic and fetal globins with little or no adult globin

Human embryonic stem cells are a promising tool to study events associated with the earliest ontogenetic stages of hematopoiesis. We describe the generation of erythroid cells from hES (H1) by subsequent processing of cells present at early and late stages of embryoid body (EB) differentiation. Kinetics of hematopoietic marker emergence suggest that CD45+ hematopoiesis peaks at late D14EB differentiation stages, although low-level CD45- erythroid differentiation can be seen before that stage. By morphologic criteria, hES-derived erythroid cells were of definitive type, but these cells both at mRNA and protein levels coexpressed high levels of embryonic (epsilon) and fetal (gamma) globins, with little or no adult globin (beta). This globin expression pattern was not altered by the presence or absence of fetal bovine serum, vascular endothelial growth factor, Flt3-L, or coculture with OP-9 during erythroid differentiation and was not culture time dependent. The coexpression of both embryonic and fetal globins by definitive-type erythroid cells does not faithfully mimic either yolk sac embryonic or their fetal liver counterparts. Nevertheless, the high frequency of erythroid cells coexpressing embryonic and fetal globin generated from embryonic stem cells can serve as an invaluable tool to further explore molecular mechanisms.

Juvenile rheumatoid arthritis in Rochester, Minnesota 1960-1993. Is the epidemiology changing?

OBJECTIVE

To examine trends in the incidence and prevalence of juvenile rheumatoid arthritis (JRA) in Rochester, Minnesota, over 33 years.

METHODS

The diagnostic retrieval system of the Rochester Epidemiology Project was utilized to screen medical records of all Rochester residents with any potential diagnoses of JRA from 1978 to 1993 (based on the American College of Rheumatology 1977 revised criteria). In addition, all cases of JRA from our previously identified cohort from 1960-1979 were verified, and the 2 data sets were combined, resulting in an incidence cohort spanning 33 years (1960-1993).

RESULTS

Of the 1,240 medical records screened, we identified 65 cases of JRA diagnosed between 1960 and 1993 (48 females, 17 males). The average followup for cases was 12.7 years (range 0-34 years) for a total of 833 person-years of observation. A bimodal distribution of age at diagnosis was observed, with peaks between 0 and 4 years and 9 and 15 years. Seventy-two percent of patients had pauciarticular-onset, 17% had polyarticular-onset, and 11% had systemic-onset disease. Progression of pauciarticular to polyarticular disease occurred in 11% of the cases. The overall age- and sex-adjusted incidence rate was 11.7 per 100,000 population (95% confidence intervals 8.7, 14.8). The incidence rate per 100,000 population was 15.0, 14.1, and 7.8 for the time periods 1960-1969, 1970-1979, and 1980-1993, respectively (P = 0.024). A 3-year, centered, moving average, which was used to display time trends in incidence, suggested a cyclical pattern, with incidence peaks in 1967, 1975, and 1987.

CONCLUSION

An overall decrease in the incidence rate over the last decade was observed, most marked in the pauciarticular- and systemic-onset subtypes. This decrease, along with the observed cyclical pattern, suggest that environmental factors may influence disease frequency.

Investigation and control of an outbreaks of legionnaires' disease in a district general hospital

Between December, 1979, and July, 1980, 12 cases of legionnaires' disease were recognised in a district general hospital. 11 of the patients probably acquired their infection within the hospital. Epidemiological and environmental studies indicated that the plumbing system and possibly also the air-conditioning cooling-tower exhaust in the new building of the hospital were the sources of infection. Chlorination of the cold-water supply and raising the hot-water temperature appeared to terminate the outbreak.

A Single-Cell Roadmap of Lineage Bifurcation in Human ESC Models of Embryonic Brain Development

During human brain development, multiple signaling pathways generate diverse cell types with varied regional identities. Here, we integrate single-cell RNA sequencing and clonal analyses to reveal lineage trees and molecular signals underlying early forebrain and mid/hindbrain cell differentiation from human embryonic stem cells (hESCs). Clustering single-cell transcriptomic data identified 41 distinct populations of progenitor, neuronal, and non-neural cells across our differentiation time course. Comparisons with primary mouse and human gene expression data demonstrated rostral and caudal progenitor and neuronal identities from early brain development. Bayesian analyses inferred a unified cell-type lineage tree that bifurcates between cortical and mid/hindbrain cell types. Two methods of clonal analyses confirmed these findings and further revealed the importance of Wnt/β-catenin signaling in controlling this lineage decision. Together, these findings provide a rich transcriptome-based lineage map for studying human brain development and modeling developmental disorders.

Persistent diarrhoea in Zairian AIDS patients: an endoscopic and histological study

To determine the aetiology of persistent diarrhoea in African patients with acquired immunodeficiency syndrome (AIDS), 42 patients with human immunodeficiency virus (HIV) and persistent diarrhoea were enrolled in a microbiological, endoscopic, and histological study. Cryptosporidium was the intestinal parasite most often identified (30%); Isospora belli was found in 12% of the patients. Histological examination of the duodenal mucosa showed a non-specific inflammatory reaction in a significantly higher number of HIV-seropositive patients (82%) than HIV-seronegative controls without diarrhoea (52%) (p = 0.02). Lymphocytes were more likely to be found in inflammatory reactions in HIV-seropositive patients than in controls (p less than 0.0001). Pathogens were observed in histological sections of the duodenum of HIV-seropositive patients only (p = 0.002) and included cryptosporidia (four patients) Isospora belli (one), Strongyloides stercoralis (one), and Cryptococcus neoformans (one). On histological examination the rectal mucosa of HIV-seropositive patients and controls was similar, except eosinophils were more likely to be present in inflammatory reaction in HIV-seropositive patients (p = 0.05) and enteric pathogens were observed only in HIV-seropositive patients (cytomegalovirus inclusion bodies (one) and Schistosoma mansoni (two). The aetiology of persistent diarrhoea in most African AIDS patients remains unclear.

The epidemiology of juvenile arthritis in Rochester, Minnesota 1960-1979

A 20-year community-based study of the epidemiology of juvenile arthritis in Rochester, Minnesota from January 1, 1960 to January 1, 1980 is described. Cases were identified using the 1977 revised American Rheumatism Association criteria for juvenile arthritis. Higher incidence and prevalence rates and a greater predominance of pauciarticular disease were observed than previously reported. Lower rates were observed when a minimum of 3 months' disease duration was used to identify incidence.

Controlled-rate freezing of human ES cells

A significant obstacle to using human embryonic stem cells (hESCs) arises from extremely poor survival associated with freezing, typically in the range of 1%. This report describes a slow controlled-rate freezing technique commonly used for mammalian embryo cryopreservation. Using a combination of surviving colony number and colony diameter, survival was determined relative to untreated hESCs. Using a dimethyl sulfoxide (DMSO) cryoprotectant and either a homemade controlled-rate freezing device or a commercial freezing device, survival rates of 20%–80% were obtained. To achieve the highest levels of survival, the critical factors were an ice crystal seed (at -7° to -10°C), a freeze rate between 0.3° and 1.8°C/min, and a rapid thaw rate using room temperature water. Slow controlled-rate cooling allows a rapid, simple, and reproducible means of cryopreserving hESCs.

Autosomal dominant granulomatous arthritis, uveitis, skin rash, and synovial cysts

In 1985, Blau reported a family with 11 members in four generations affected by granulomatous arthritis, iritis, skin rash, and periarticular synovial cysts. We report a second family with these abnormalities, thereby confirming this syndrome as a distinct familial entity with transmission compatible with autosomal dominant inheritance. Affected members in our family included a mother and two daughters. Disease onset was at 10 months to 8 years of age. Each had uveitis, symmetric polyarthritis, and synovial cysts overlying the ankle and wrist joints. In addition, both daughters had an intermittent generalized erythematous papular rash that on biopsy revealed noncaseating granulomatous infiltration. All three patients improved during alternate-day steroid therapy. Recognition of this disorder as distinct from other, more common causes of arthritis is important because of the apparent autosomal dominant transmission and because of the excellent responses to low-dose steroid therapy.

Integrated intracellular organization and its variations in human iPS cells

Understanding how a subset of expressed genes dictates cellular phenotype is a considerable challenge owing to the large numbers of molecules involved, their combinatorics and the plethora of cellular behaviours that they determine1,2. Here we reduced this complexity by focusing on cellular organization-a key readout and driver of cell behaviour3,4-at the level of major cellular structures that represent distinct organelles and functional machines, and generated the WTC-11 hiPSC Single-Cell Image Dataset v1, which contains more than 200,000 live cells in 3D, spanning 25 key cellular structures. The scale and quality of this dataset permitted the creation of a generalizable analysis framework to convert raw image data of cells and their structures into dimensionally reduced, quantitative measurements that can be interpreted by humans, and to facilitate data exploration. This framework embraces the vast cell-to-cell variability that is observed within a normal population, facilitates the integration of cell-by-cell structural data and allows quantitative analyses of distinct, separable aspects of organization within and across different cell populations. We found that the integrated intracellular organization of interphase cells was robust to the wide range of variation in cell shape in the population; that the average locations of some structures became polarized in cells at the edges of colonies while maintaining the 'wiring' of their interactions with other structures; and that, by contrast, changes in the location of structures during early mitotic reorganization were accompanied by changes in their wiring.

A comparison of NIH-approved human ESC lines

In October 2003, the NIH established three extramural "Exploratory Centers for Human Embryonic Stem Cell Research." Our center acquired 15 of the 22 NIH-approved cell lines. Lines were tested for: (a) freedom from mycoplasma contamination; (b) appropriate pattern of gene expression during self-renewal and differentiation; (c) ability to adapt to uniform culture conditions; (d) ability to grow at clonal densities; (e) karyotype; (f) growth efficiency; and (g) efficiency of stable transfection following electroporation. One line harbored mycoplasma. Ten lines were converted to uniform conditions. Nine lines were fully characterized. Human ESC (hESC) lines varied markedly with respect to growth efficiency as measured by the amount of time it took to plate and double (31-57 hours), cloning efficiency (0.8%-9.2%), and stable transfection rates following electroporation (0%-53% relative to a standard mouse ESC line). One hESC line had an unstable karyotype at an early passage. Modifications of the proposed Material Transfer Agreements with hESC suppliers were required to improve accessibility to hESC lines by local researchers. The NIH-approved hESC lines vary in their behavior in culture. Many hESC lines can be maintained using culture conditions less onerous than those recommended by their suppliers. Intellectual property issues pose a significant obstacle to research using NIH-approved hESC lines.

Primary anaplastic large cell lymphoma of the lung: a clinicopathologic study of five patients

Primary anaplastic large-cell lymphoma is a rare malignancy in the lung. Anaplastic large-cell lymphoma characteristically involves the lymph nodes or skin, with few reports from other sites. We studied the clinical and pathologic features of five cases of anaplastic large-cell lymphoma limited to the lungs. The patients were three women and two men aged 27 to 66 years (mean, 44.6 y) The tumors ranged in size from 1.1 to 5 cm. All patients were CD 30 (Ki-1) positive and CD 15 (LeuM-1) negative. Epithelial membrane antigen immunoreactivity was seen in two patients. Epstein-Barr virus was not detected by immunohistochemistry (four patients tested) or by polymerase chain reaction studies (three patients tested). The immunophenotypes were T cell (n = 3) and null (n = 2). Gene rearrangement studies supported the immunophenotypic findings. One patient who had underlying HIV infection died of infectious complications. One patient died at 6 months. Two patients developed recurrent disease and are alive after 42 and 51 months of follow-up. The remaining patient is alive at 8 years of follow-up without evidence of disease. ALCL can mimic metastatic or primary carcinoma and should be considered in the differential diagnosis of large cell neoplasms of the lung.

Immunoglobulin complexes in sera of patients with malignancy

Sera frour 146 patients with malignancy, 59 normal controls and 42 patients hospitalized with non-malignant diseases were examined by a precipitin test with monoclonal rheumatoid factor (mRF) for the presence of circulating immune complexes containing IgG. Forty-two (29%) of the sera from cancer patients but only two of the sera from patients in each of the control groups contained such material. Similar results were obtained with a radioimmunoassay for immune complexes based on the same mRF. Sera from 23 of 65 patients with metastatic malignancy (35%) had elevated levels of immune complexes by this latter test. The presence of the material was not related to the source of malignancy, presence of carcinoembryonic or hepatitis antigens or of such autoantibodies as rheumatoid factor or anti-DNA. By density gradient ultracentrifugation the reacting material was identified as being of molecular size 19s or greater. It has not yet been further characterized with regard to the nature of any antigens present.

Diverse hematopoietic potentials of five human embryonic stem cell lines

Despite a growing body of literature concerning the hematopoietic differentiation of human embryonic stem cells (hESCs), the full hematopoietic potential of the majority of existing hESC lines remains unknown. In this study, the hematopoietic response of five NIH-approved hESC lines (H1, hSF6, BG01, BG02, and BG03) was compared. Our data show that despite expressing similar hESC markers under self-renewing conditions and initiating mesodermal differentiation under spontaneous differentiation conditions, marked differences in subsequent hematopoietic differentiation potential among these lines existed. A high degree of hematopoietic differentiation was attained only by H1 and BG02, whereas this process appeared to be abortive in nature for hSF6, BG01, and BG03. This difference in hematopoietic differentiation predisposition was readily apparent during spontaneous differentiation, and further augmented under hematopoietic-inducing conditions. This predisposition appeared to be intrinsic to the specific hESC line and independent of passage number or gender karyotype. Interestingly, H1 and BG02 displayed remarkable similarities in their kinetics of hematopoietic marker expression, hematopoietic colony formation, erythroid differentiation, and globin expression, suggesting that a similar, predetermined differentiation sequence is followed. The identification of intrinsic and extrinsic factors governing the hematopoietic differentiation potential of hESCs will be of great importance for the putative clinical utility of hESC lines.