Immunocompetent murine model of Ewing sarcoma reveals role for TGFβ inhibition to enhance immune infiltrates in Ewing tumors during radiation

Ewing sarcoma (ES) is an aggressive cancer diagnosed in adolescents and young adults. The fusion oncoprotein (EWSR1::FLI1) that drives Ewing sarcoma is known to downregulate TGFBR2 expression (part of the TGFβ receptor). Because TGFBR2 is downregulated, it was thought that TGFβ likely plays an inconsequential role in Ewing biology. However, the expression of TGFβ in the Ewing tumor immune microenvironment (TIME) and functional impact of TGFβ in the TIME remains largely unknown given the historical lack of immunocompetent preclinical models. Here, we use single-cell RNAseq analysis of human Ewing tumors to show that immune cells, such as NK cells, are the largest source of TGFβ production in human Ewing tumors. We develop a humanized (immunocompetent) mouse model of ES and demonstrate distinct TME signatures and metastatic potential in these models as compared to tumors developed in immunodeficient mice. Using this humanized model, we study the effect of TGFβ inhibition on the Ewing TME during radiation therapy, a treatment that both enhances TGFβ activation and is used to treat aggressive ES. Utilizing a trivalent ligand TGFβ TRAP to inhibit TGFβ, we demonstrate that in combination with radiation, TGFβ inhibition both increases ES immune cell infiltration and decreases lung metastatic burden in vivo . The culmination of these data demonstrates the value of humanized models to address immunobiologic preclinical questions in Ewing sarcoma and suggests TGFβ inhibition as a promising intervention during radiation therapy to promote metastatic tumor control.

Specific Polo-Like Kinase 1 Expression in Nodular Lymphocyte-Predominant Hodgkin Lymphoma Suggests an Intact Immune Surveillance Program

Nodular lymphocyte-predominant Hodgkin lymphoma (NLPHL) is a rare and relatively indolent B-cell lymphoma. Characteristically, the [lymphocyte-predominant (LP)] tumor cells are embedded in a microenvironment enriched in lymphocytes. More aggressive variants of mature B-cell and peripheral T-cell lymphomas exhibit nuclear expression of the polo-like kinase 1 (PLK1) protein, stabilizing MYC (alias c-myc) and associated with worse clinical outcomes. This study demonstrated expression of PLK1 in the LP cells in 100% of NLPHL cases (n = 76). In contrast, <5% of classic Hodgkin lymphoma cases (n = 70) showed PLK1 expression within the tumor cells. Loss-of-function approaches demonstrated that the expression of PLK1 promoted cell proliferation and increased MYC stability in NLPHL cell lines. Correlation with clinical parameters revealed that the increased expression of PLK1 was associated with advanced-stage disease in patients with NLPHL. A multiplex immunofluorescence panel coupled with artificial intelligence algorithms was used to correlate the composition of the tumor microenvironment with the proliferative stage of LP cells. The results showed that LP cells with PLK1 (high) expression were associated with increased numbers of cytotoxic and T-regulatory T cells. Overall, the findings demonstrate that PLK1 signaling increases NLPHL proliferation and constitutes a potential vulnerability that can be targeted with PLK1 inhibitors. An active immune surveillance program in NLPHL may be a critical mechanism limiting PLK1-dependent tumor growth.

The molecular landscape and other distinctive features of primary cutaneous follicle center lymphoma

Primary cutaneous follicle center lymphoma (PCFCL) is distinguished from other follicular lymphomas (FLs) based on its clinicopathologic features including diminished CD10 and frequent lack of BCL2 rearrangements (R). Whether newer germinal center-associated markers would also be less commonly expressed and whether mutational studies would support its segregation from classic FL and FL subsets, including those which also typically lack BCL2R, are uncertain. To address these questions, 22 PCFCLs were stained for myocyte enhancer factor 2B (MEF2B) and human germinal center-associated lymphoma (HGAL), and targeted next-generation sequencing was performed with results compared to a meta-analysis of FL, pediatric-type FL (PTFL), low stage FL (LSFL) and other FL subsets. Selected fluorescence in situ hybridization studies were also performed. Although 27% of cases lacked CD10, all tested were MEF2B+ and HGAL+. The most common somatic mutations in the 12 to 19 analyzable PCFCL were TNFRSF14 (40%, plus 10% with 1p36 deletions), followed by CREBBP, TNFAIP3, KMT2D, SOCS1, EP300, STAT6, and FOXO1 (17-25%). Three of the most commonly mutated genes in FL (KMT2D, CREBBP, and BCL2) were significantly less commonly mutated in PCFCL than in FL, and TNFAIP was more commonly mutated with no difference for TNFRSF14 between PCFCL and FL or PTFL. CREBBP was also less frequently mutated than in LSFL but more frequently mutated than in PTFL. MAP2K1 mutations were much more common in PTFL (44% versus 0%). Two of 22 of the PCFCL had a BCL2 rearrangement and zero of 12 had a BCL6 rearrangement. These findings, while showing well-recognized and new shared features between PCFCL and other FL, highlight a distinctive mutational profile further supporting its recognition as a distinct entity.

Data Resource Profile: the Scottish Social Care Survey (SCS) and the Scottish Care Home Census (SCHC)

Introduction

Linked health care datasets have been used effectively in Scotland for some time. Use of social care data has been much more limited, partly because responsibility for these services is distributed across multiple local authorities. However, there are substantial interactions between health and social care (also known internationally as long-term care) services, and keen policy interest in better understanding these. We introduce two social care resources that can now be linked to health datasets at a population level across Scotland to study these interdependencies. These data emerge from the Scottish Government’s centralised collation of data from mandatory returns provided by local authorities and care homes.

Methods

Deterministic and Probabilistic methods were used to match the Social Care Survey (SCS) and Scottish Care Home Census (SCHC) to the Community Health Index (CHI) number via the National Records of Scotland (NRS) Research Indexing Spine.

Results

For the years 2010/11 to 2015/16, an overall match rate of 91.2% was achieved for the SCS to CHI from 31 of Scotland’s 32 local authority areas. This rate varied from 76.7% to 98.5% for local authority areas. A match rate of 89.8% to CHI was achieved for the SCHC in years 2012/13 to 2015/16 but only 52.5% for the years 2010/11 to 2011/12.

Conclusion

Indexing of the SCS and SCHC to CHI offers a new and rich resource of data for health and social care research.

Is that a rodent in your luggage? A mixed method approach to describe bushmeat importation into the United States

Bushmeat, defined as meat derived from wild animals, is a potential source of zoonotic pathogens. Bushmeat from restricted animals is illegal to import into the United States under US federal regulations. We reviewed US Centers for Disease Control and Prevention (CDC) port of entry surveillance records from September 2005 through December 2010 and conducted focus group studies to describe trends in and reasons for bushmeat importation into the United States. In total, 543 confiscated bushmeat items were recorded. Half of the confiscated bushmeat items identified were rodents. Africa was the most frequent continent of origin. Seasonality was evident, with bushmeat confiscations peaking in late spring to early summer. Four times more bushmeat was confiscated during an enhanced surveillance period in June 2010 compared with the same period in previous years, suggesting that routine surveillance underestimated the amount of bushmeat detected at US Ports of Entry. Focus groups held in three major US cities revealed that bushmeat importation is a multifaceted issue. Longstanding cultural practices of hunting and eating bushmeat make it difficult for consumers to acknowledge potential health and ecologic risks. Also, US merchants selling African goods, including bushmeat, in their stores have caused confusion among importers as to whether importation is truly illegal. Enhancing routine surveillance for bushmeat and consistent enforcement of penalties at all ports of entry, along with health education aimed at bushmeat importers, might be useful to deter illegal importation.

Bone marrow osteoblast damage by chemotherapeutic agents

Hematopoietic reconstitution, following bone marrow or stem cell transplantation, requires a microenvironment niche capable of supporting both immature progenitors and stem cells with the capacity to differentiate and expand. Osteoblasts comprise one important component of this niche. We determined that treatment of human primary osteoblasts (HOB) with melphalan or VP-16 resulted in increased phospho-Smad2, consistent with increased TGF-β1 activity. This increase was coincident with reduced HOB capacity to support immature B lineage cell chemotaxis and adherence. The supportive deficit was not limited to committed progenitor cells, as human embryonic stem cells (hESC) or human CD34+ bone marrow cells co-cultured with HOB pre-exposed to melphalan, VP-16 or rTGF-β1 had profiles distinct from the same populations co-cultured with untreated HOB. Functional support deficits were downstream of changes in HOB gene expression profiles following chemotherapy exposure. Melphalan and VP-16 induced damage of HOB suggests vulnerability of this critical niche to therapeutic agents frequently utilized in pre-transplant regimens and suggests that dose escalated chemotherapy may contribute to post-transplantation hematopoietic deficits by damaging structural components of this supportive niche.

Water and sanitation issues for persons with disabilities in low- and middle-income countries: a literature review and discussion of implications for global health and international development

The critical importance of unrestricted access to clean drinking water and basic sanitation for all is highlighted in Millennium Development Goal 7, which calls for the reduction by half of the proportion of people without such access by 2015. Unfortunately, little attention has been paid to the needs of such access for the one billion people living with a disability worldwide, despite the fact that the right to equal access for all international development initiatives is guaranteed in the new United Nations Convention on the Rights of Persons with Disabilities. In this paper, we review what is currently known about access to water and sanitation for persons with disabilities in low- and middle-income countries from the perspective of both international development and global health, and identify existing gaps in research, practice and policy that are of pressing concern if the water and sanitation needs of this large - and largely overlooked - population are to be addressed.

The "Black Turbinate" sign: An early MR imaging finding of nasal mucormycosis

Rhinocerebral mucormycosis is a rare angioinvasive fungal infection that has a strong predilection for patients with poorly controlled diabetes and immunosuppression. Initial presenting symptoms are nonspecific and frequently are attributed to more mundane sinonasal and orbital pathologies. Early diagnosis and treatment are essential for survival and minimizing neurologic sequelae. CT and MR imaging are often used in the diagnostic work-up; however, CT findings are nonspecific.

Effects of carnitine and taurine on fatty acid metabolism and lipid accumulation in the liver of cats during weight gain and weight loss

OBJECTIVE

To determine the effects of carnitine (Ca) or taurine (Ta) supplementation on prevention of lipid accumulation in the liver of cats.

ANIMALS

24 adult cats.

PROCEDURE

Cats were fed a weight-gaining diet sufficient in n-6 polyunsaturated fatty acids (PUFAs), low in long-chain n-3 PUFAs (n-3 LPUFA), and containing corn gluten for 20 weeks. Cats gained at least 30% in body weight and were assigned to 4 weight-reduction diets (6 cats/diet) for 7 to 10 weeks (control diet, control plus Ca, control plus Ta, and control plus Ca and Ta).

RESULTS

Hepatic lipids accumulated significantly during weight gain and weight loss but were not altered by Ca orTa after weight loss. Carnitine significantly increased n-3 and n-6 LPUFAs in hepatic triglycerides, decreased incorporation of 13C palmitate into very-low-density lipoprotein and hepatic triglycerides, and increased plasma ketone bodies. Carnitine also significantly increased weight loss but without altering the fat to lean body mass ratio. Taurine did not significantly affect any variables. Diets low in n-3 LPUFAs predisposed cats to hepatic lipidosis during weight gain, which was further exacerbated during weight loss. Mitochondrial numbers decreased during weight gain and weight loss but were not affected by treatment. Carnitine improved fatty acid oxidation and glucose utilization during weight loss without correcting hepatic lipidosis.

CONCLUSIONS AND CLINICAL RELEVANCE

The primary mechanism leading to hepatic lipidosis in cats appears to be decreased fatty acid oxidation. Carnitine may improve fatty acid oxidation but will not ameliorate hepatic lipidosis in cats fed a diet low in n-3 fatty acids.

In vivo effect of coronary laser angioplasty on atherosclerotic plaques: histopathologic analysis

Information from histopathologic examination of coronary arterial atherosclerotic plaques treated with in vivo laser energy is sparse. Directional atherectomy provides biopsies for study of tissue changes (injury) due to coronary arterial debulking devices, including laser. Sixteen patients who presented with acute ischemic coronary syndromes underwent debulking of a total of 17 obstructive intracoronary lesions with pulsed-wave holmium:YAG laser (2.1 microm wavelength). Laser was performed with the "pulse and retreat" technique which incorporates slow catheter advancement (0.5-1 mm/s) with controlled emission of energy. Immediately postlasing, directional atherectomy was utilized to obtain irradiated plaque tissue for pathologic examination. Extent of laser-induced tissue injury to plaques was graded as 0 (no tissue damage), 1 (small foci or charring and vacuoles), 2 (large amount of charring, edge disruption and vacuoles) and 3 (extensive tissue damage). Angiographically and clinically, all 17 lesions were successfully debulked with the laser energy (mean 47+/-25 pulses), with a reduction of target lesion percent diameter stenosis from 92+/-6% to 47+/-25%. Adjunct balloon dilations further reduced the target lesions to a final of 10+/-10% stenosis. The histopathologic examination of the lased specimens demonstrated that 13 lesions (76%) had no evidence of laser-induced injury (Grade 0). Four lesions had low-level injury (Grade 1), and none had evidence of Grade 2 or 3 laser-induced trauma. Therefore, a laser debulking technique, which incorporates slow catheter advancement with controlled emission of pulses, does not cause significant injurious effects to the irradiated plaque.

An analysis of swimming performance in the Norway lobster, Nephrops norvegicus L. infected by a parasitic dinoflagellate of the genus Hematodinium

Various components of swimming performance were measured in uninfected Norway lobsters (Nephrops norvegicus) and compared to animals at different stages of infection by a parasitic dinoflagellate (Hematodinium sp.). Animals showed a progressive decline in overall swimming performance as infection severity increased, with reductions in the number of tail-flips performed, the number of swimming bouts and the total distance travelled by swimming. The velocity of the first (giant-fibre mediated) tail flip and average velocity over the swimming bout were also significantly reduced in infected lobsters. Possible reasons for this decreased swimming performance are suggested and the implications of this for predator avoidance of infected lobsters in the benthic habitat, and for capture of Nephrops by trawl rigs are discussed.

Carboplatin and paclitaxel, alone and in combination: dose escalation, measurement of renal function, and role of the p53 tumor suppressor gene

In this pharmacokinetic and dose-escalation study of the carboplatin/paclitaxel (Taxol; Bristol-Myers Squibb Company, Princeton, NJ) combination, patients were randomly assigned to receive paclitaxel either as a 1-hour or a 3-hour infusion. The 1-hour infusion was feasible, with maximum tolerated doses similar to those previously reported for a 3-hour infusion. Using patients' age, height, plasma creatinine, and plasma creatine kinase provided an improved estimate of the glomerular filtration rate compared with the more traditional creatinine-based formulas according to population analysis of data derived from glomerular filtration rate estimates performed by an isotope method. Studies of the p53 gene sequence of ovarian tumors at diagnosis suggest that p53 mutations are a potent predictor of response to subsequent treatment with carboplatin.

Renal replacement by regular haemodialysis therapy and renal transplantation in Barbados: 1979 to 1997

We have reviewed our delivery of highly sophisticated medical therapy, haemodialysis and renal transplantation in a Caribbean setting. The purpose has been to reflect local outcomes in relation to mortality and survival, but comparisons with a vastly larger database have been attempted. Such comparisons are extremely difficult due to methodological differences and the fact that facilities contributing to that database vary considerably with regard to patient age, gender, ethnicity and comorbidity. Nonetheless, the crude data available provide important justification for the existence of regular haemodialysis and its adjunctive therapy of renal transplantation in the Caribbean.

Lactoferrin expression in mammary epithelial cells is mediated by changes in cell shape and actin cytoskeleton

Lactoferrin is a secreted iron binding protein which is expressed during normal functional development of mammary epithelium. Murine mammary epithelial cell lines competent for milk protein expression were used to identify microenvironmental factors that regulate lactoferrin expression. While lactoferrin was not expressed in adherent monolayer cultures under standard subconfluent conditions on plastic, lactoferrin mRNA and protein steadily accumulated when the cells aggregated to form spheroids on a reconstituted basement membrane gel. However, unlike other milk proteins such as beta-casein, lactoferrin expression was also induced at high cell density in the absence of exogenously added basement membrane or prolactin. These results led us to examine whether changes in cell growth, cell-cell interactions and/or cell shape were responsible for regulation of lactoferrin gene expression. Rounded, non-proliferating cells in suspension in serum-free medium expressed lactoferrin even as single cells. Conversely, lactoferrin expression could be inhibited in non-proliferative cells in serum-free medium by maintaining them in contact with an air-dried extracellular matrix which caused the cells to retain flat, spread morphologies. These findings indicated that cessation of cell growth was not sufficient, that cell-cell interactions were not required, and that cell culture conditions which minimize cell spreading may be important in maintaining lactoferrin expression. Additional data supporting this latter concept were generated by treating spread cells with cytochalasin D. The resulting disruption of microfilament assembly induced both cell rounding and lactoferrin expression. Shape-dependent regulation of lactoferrin mRNA was both transcriptional and post-transcriptional. Surprisingly, treatment of rounded cells with a transcription inhibitor, actinomycin D, produced a stabilization of lactoferrin mRNA, suggesting that transcription of an unstable factor is required for degradation of lactoferrin mRNA. Importantly, lactoferrin mRNA expression was regulated similarly in early passage normal human mammary epithelial cells. In vivo, the changing extracellular matrix components of the mammary gland during different stages of normal and abnormal growth and differentiation may provide different physical constraints on the configurations of cell surface molecules. These physical constraints may be communicated to the cell interior through mechanical changes in the cytoskeleton. Unlike beta-casein whose expression is upregulated by specific integrin-mediated signals, lactoferrin may be representative of a class of proteins synthesized in the mammary gland using basal transcriptional and translational machinery. The suppression of lactoferrin expression that is observed in monolayer culture and in malignant tissues may reflect inappropriate cell shapes and cytoskeletal structures that are manifested under these conditions.

A phase I clinical study of the antipurine antifolate lometrexol (DDATHF) given with oral folic acid

Lometrexol is an antifolate which inhibits glycinamide ribonucleotide formyltransferase (GARFT), an enzyme essential for de novo purine synthesis. Extensive experimental and limited clinical data have shown that lometrexol has activity against tumours which are refractory to other drugs, notably methotrexate. However, the initial clinical development of lometrexol was curtailed because of severe and cumulative antiproliferative toxicities. Preclinical murine studies demonstrated that the toxicity of lometrexol can be prevented by low dose folic acid administration, i.e. for 7 days prior to and 7 days following a single bolus dose. This observation prompted a Phase I clinical study of lometrexol given with folic acid supplementation which has confirmed that the toxicity of lometrexol can be markedly reduced by folic acid supplementation. Thrombocytopenia and mucositis were the major toxicities. There was no clear relationship between clinical toxicity and the extent of plasma folate elevation. Associated studies demonstrated that lometrexol plasma pharmacokinetics were not altered by folic acid administration indicating that supplementation is unlikely to reduce toxicity by enhancing lometrexol plasma clearance. The work described in this report has identified for the first time a clinically acceptable schedule for the administration of a GARFT inhibitor. This information will facilitate the future evaluation of this class of compounds in cancer therapy.

Clinical pharmacokinetic and pharmacodynamic studies with the nonclassical antifolate thymidylate synthase inhibitor 3, 4-dihydro-2-amino-6-methyl-4-oxo-5-(4-pyridylthio)-quinazolone dihydrochloride (AG337) given by 24-hour continuous intravenous infusion

3,4-Dihydro-2-amino-6-methyl-4-oxo-5-(4-pyridylthio)-quinazolon e dihydrochloride (AG337) is a nonclassical inhibitor of thymidylate synthase (TS) designed to avoid potential resistance mechanisms that can limit the activity of classical antifolate antimetabolites. A clinical pharmacokinetic and pharmacodynamic study of AG337 given as a 24-h i.v. infusion was performed. Thirteen patients received 27 courses over the dose range 75-1350 mg/m2. Plasma AG337 concentrations were achieved which, in preclinical models, were associated with antitumor effects. AG337 clearance was saturable, and the pharmacokinetics of the drug at doses above 300 mg/m2 was best described by a one-compartment model with saturable elimination (median Km = 6.5 microgram/ml; range, 4.1-13 microgram/ml; median Vmax = 2.0 microgram/ml/h/m2; range, 0.96-5.6 microgram/ml/h/m2). Following the end of the infusion, AG337 was cleared rapidly (t1/2, 53-193 min), and levels were less than 0.2 microgram/ml in all patients by 48 h. Plasma protein binding was 96-98%, and the urinary excretion of AG337 as unchanged drug did not exceed 30% of the dose administered. Measurements of plasma deoxyuridine (dUrd) concentrations showed that doses of 600 mg/m2 and above of AG337 produced a consistent elevation in plasma dUrd levels (60-290%), suggesting that TS inhibition was being achieved in patients. However, in all cases dUrd concentrations had returned to pretreatment levels 24 h after the end of the infusion, suggesting that TS inhibition was not maintained. Local toxicity, probably due to the infusate pH, was the only significant adverse effect observed. These studies have shown that cytotoxic AG337 plasma concentrations can be readily achieved without acute toxicity and that these concentrations are associated with elevations in plasma dUrd levels. The lack of prolonged dUrd elevations indicates that extended administration should be explored using central line or p.o. administration to avoid local toxicity.

Cellular growth and survival are mediated by beta 1 integrins in normal human breast epithelium but not in breast carcinoma

We previously established a rapid three-dimensional assay for discrimination of normal and malignant human breast epithelial cells using a laminin-rich reconstituted basement membrane. In this assay, normal epithelial cells differentiate into well-organized acinar structures whereas tumor cells fail to recapitulate this process and produce large, disordered colonies. The data suggest that breast acinar morphogenesis and differentiation is regulated by cell-extra-cellular matrix (ECM) interactions and that these interactions are altered in malignancy. Here, we investigated the role of ECM receptors (integrins) in these processes and report on the expression and function of potential laminin receptors in normal and tumorigenic breast epithelial cells. Immunocytochemical analysis showed that normal and carcinoma cells in a three-dimensional substratum express profiles of integrins similar to normal and malignant breast tissues in situ. Normal cells express alpha 1, alpha 2, alpha 3, alpha 6, beta 1 and beta 4 integrin subunits, whereas breast carcinoma cells show variable losses, disordered expression, or downregulation of these subunits. Function-blocking experiments using inhibitory anti-integrin subunit antibodies showed a &gt; 5-fold inhibition of the formation of acinar structures by normal cells in the presence of either anti-beta 1 or anti-alpha 3 antibodies, whereas anti-alpha 2 or -alpha 6 had little or no effect. In experiments where collagen type I gels were used instead of basement membrane, acinar morphogenesis was blocked by anti-beta 1 and -alpha 2 antibodies but not by anti-alpha 3. These data suggest a specificity of integrin utilization dependent on the ECM ligands encountered by the cell. The interruption of normal acinar morphogenesis by anti-integrin antibodies was associated with an inhibition of cell growth and induction of apoptosis. Function-blocking antibodies had no inhibitory effect on the rate of tumor cell growth, survival or capacity to form colonies. Thus under our culture conditions breast acinar formation is at least a two-step process involving beta 1-integrin-dependent cellular growth followed by polarization of the cells into organized structures. The regulation of this pathway appears to be impaired or lost in the tumor cells, suggesting that tumor colony formation occurs by independent mechanisms and that loss of proper integrin-mediated cell-ECM interaction may be critical to breast tumor formation.

Laminin mediates tissue-specific gene expression in mammary epithelia

Tissue-specific gene expression in mammary epithelium is dependent on the extracellular matrix as well as hormones. There is good evidence that the basement membrane provides signals for regulating beta-casein expression, and that integrins are involved in this process. Here, we demonstrate that in the presence of lactogenic hormones, laminin can direct expression of the beta-casein gene. Mouse mammary epithelial cells plated on gels of native laminin or laminin-entactin undergo functional differentiation. On tissue culture plastic, mammary cells respond to soluble basement membrane or purified laminin, but not other extracellular matrix components, by synthesizing beta-casein. In mammary cells transfected with chloramphenicol acetyl transferase reporter constructs, laminin activates transcription from the beta-casein promoter through a specific enhancer element. The inductive effect of laminin on casein expression was specifically blocked by the E3 fragment of the carboxy terminal region of the alpha 1 chain of laminin, by antisera raised against the E3 fragment, and by a peptide corresponding to a sequence within this region. Our results demonstrate that laminin can direct tissue-specific gene expression in epithelial cells through its globular domain.

Testing the FOCOMETER--A new refractometer

The FOCOMETER, an optometer which measures spherical refractive errors, is intended to provide rural or economically disadvantaged populations spherical prescriptions without the need for complicated protocols, expensive equipment, or electricity. FOCOMETER readings were compared with the spherical equivalent determined from autorefraction and subjective trial lens refractions in children, and with retinoscopy in adults. Over the range of refractive errors tested (-4 to +5 D) reasonably close readings, within one-half a diopter, were found for comparisons with autorefraction and retinoscopy and about one-tenth of a diopter difference was found between subjective refractions and the FOCOMETER.

Interferon alfa-2b in addition to chlorambucil in the treatment of follicular lymphoma: preliminary results of a randomized trial in progress

One hundred and twenty four patients with follicular lymphoma (32 with Stage III and 92 with Stage IV disease) have been randomized to receive chlorambucil alone or chlorambucil plus interferon alfa-2b. Responding patients are then randomized to receive either interferon alfa-2b maintenance therapy for up to 12 months or no further treatment. One hundred and eight patients are evaluable for response, the remainder are still receiving initial therapy. Clinical remission (complete or good partial remission) was achieved in 42/59 (71%) patients receiving chlorambucil alone and in 27/49 (55%) patients receiving the combination (P = NS). Preliminary analysis of remission duration shows a trend in favour of those patients receiving interferon throughout (P = 0.02). There is no significant difference between the groups in terms of survival, at a median follow up of 2.5 years. Interferon-associated toxicity was minor in most patients but led to discontinuation of therapy in six cases. Larger trials with longer follow-up periods are needed to confirm the beneficial role of interferon in the treatment of follicular lymphoma.

Control of mammary epithelial differentiation: basement membrane induces tissue-specific gene expression in the absence of cell-cell interaction and morphological polarity

Functional differentiation in mammary epithelia requires specific hormones and local environmental signals. The latter are provided both by extracellular matrix and by communication with adjacent cells, their action being intricately connected in what appears to be a cascade of events leading to milk production. To distinguish between the influence of basement membrane and that of cell-cell contact in this process, we developed a novel suspension culture assay in which mammary epithelial cells were embedded inside physiological substrata. Single cells, separated from each other, were able to assimilate information from a laminin-rich basement membrane substratum and were induced to express beta-casein. In contrast, a stromal environment of collagen I was not sufficient to induce milk synthesis unless accompanied by cell-cell contact. The expression of milk proteins did not depend on morphological polarity since E-cadherin and alpha 6 integrin were distributed evenly around the surface of single cells. In medium containing 5 microM Ca2+, cell-cell interactions were impaired in small clusters and E-cadherin was not detected at the cell surface, yet many cells were still able to produce beta-casein. Within the basement membrane substratum, signal transfer appeared to be mediated through integrins since a function-blocking anti-integrin antibody severely diminished the ability of suspension-cultured cells to synthesize beta-casein. These results provide evidence for a central role of basement membrane in the induction of tissue-specific gene expression.

Adjuvant effect of human growth hormone with an inactivated flavivirus vaccine

Vaccines made by inactivating pathogenic microorganisms have been dramatically successful in controlling diseases in humans and animals. Despite their successes, they have a major disadvantage in that several inoculations are required for them to be effective. To overcome this problem, a commercial inactivated vaccine preparation against tickborne encephalitis was combined with human growth hormone (HGH). This formulation produced complete protection in a murine model with only one dose of vaccine, apparently by binding hormone and antigen to an insoluble matrix containing aluminium hydroxide. Thus it is postulated that when virus-specific lymphocytes are attracted to the site of injection, the hormone is at a high local concentration and stimulates the clonal expansion of antigen-specific T cells. The development of genetically engineered HGH now gives unlimited supplies of hormone, potentially resulting in an increase in efficacy of a wide variety of vaccines, especially those needing prolonged immunization schedules such as those being developed to combat human immunodeficiency virus infection.

Interferon-alpha 2b in the treatment of follicular lymphoma: preliminary results of a trial in progress

Since 1985 the combination of chlorambucil (10 mg daily, initially for six weeks, then alternating fortnights for 12 weeks) and interferon-alpha 2b (Schering-Plough; 2 x 10(6) U/m2 three times weekly by subcutaneous injection for 18 weeks) has been compared in a randomised trial with chlorambucil alone in previously untreated patients with stage III or IV follicular lymphoma. Responding patients have subsequently been randomised to receive maintenance interferon-alpha 2b or no further treatment. Of the 124 treated patients, 108 are evaluable for response with a median follow-up of 30 months. The major toxicity was myelosuppression which was more frequent with chlorambucil and IFN alpha 2b in combination than with chlorambucil alone (P less than 0.01). There was no treatment-related mortality. Actuarial survival at three years is 75% for all patients, regardless of therapy. There was no significant difference in response rate according to initial therapy. For the 60 patients achieving a good response to initial therapy who have entered the second part of the trial, there has been a significant prolongation of remission duration in favour of maintenance IFN-alpha 2b (median not yet reached versus two years for the 'no treatment' arm, P less than 0.015). Fewest relapses have been seen in patients who received IFN-alpha 2b throughout. Accrual to this trial continues; this preliminary analysis indicates that maintenance IFN-alpha 2b may extend remission duration in follicular lymphoma.

Mutation of the human FMS gene (M-CSF receptor) in myelodysplastic syndromes and acute myeloid leukemia

We studied 41 patients with myelodysplastic syndromes or acute myeloid leukemia to assess the presence of point mutations in the human FMS gene (M-CSF receptor). Using the polymerase chain reaction and hybridization of oligonucleotide probes to the amplified sequences, we have detected mutations in eight of 41 patients, at codons 301 and 969. In vitro work has highlighted mutations at these codons as being oncogenic. We now report the detection of potentially activating mutations of the human FMS gene in vivo. The consequence of these mutations in the multistep pathogenesis of myeloid malignancy and their relevance to prognosis remains to be determined.

Tissue distortion in three-dimensional reconstruction of wax or plastic embedded microscopic structures

Three-dimensional reconstruction at the light microscopic level depends on obtaining reliable serial sections without "distortion" i.e., expansion and compression during section preparation. We have studied the extent of such distortion in serial sections from paraffin and resin embedded blocks of brain, kidney, liver and lung, using an IBAS 2000 Image Analyser. We found that, taking the uncut block as 100%, the section area, perimeter and minimum diameter varied by no more than 8%, except for the lung sections which varied up to 14%. There was no progressive compression due to knife bluntening. Resin sections also varied up to 8% (16% for lungs) but in addition creasing was a problem. We conclude that, provided the serial sectioning is carefully standardised for block shape and orientation, floating out temperature and time, serial paraffin sections are more suitable for three dimensional reconstruction than resin sections.