Single-cell molecular signature of pathogenic T helper subsets in type 2-associated disorders in humans

To unravel the heterogeneity and molecular signature of effector memory Th2 cells (Tem2), we analyzed 23 individuals' PBMCs of filaria-infected (Filaria+) and 24 healthy volunteers (Filaria-), with or without coincident house dust mite (HDM) allergic sensitization. Flow cytometry revealed 3 CD4+ Tem subsets - CCR4+CCR6+CRTH2- Tem17, CCR4+CCR6-CRTH2+ Tem2, and CCR6+CCR4+CRTH2+ Tem17.2 - markedly enriched in Filaria+ individuals. These subsets were sorted and analyzed by multiomic single-cell RNA immunoprofiling. SingleR-annotated Th2 cells from Tem2 and Tem17.2 cell subsets had features of pathogenic Th2 effector cells based on their transcriptional signatures, with downregulated CD27 and elevated expression levels of ITGA4, IL17RB, HPGDS, KLRB1, PTGDR2, IL9R, IL4, IL5, and IL13 genes. When the Filaria+ individuals were subdivided based on their allergic status, Tem2 cells in HDM+Filaria+ individuals showed an overall reduction in TCR diversity, suggesting the occurrence of antigen-driven clonal expansion. Moreover, HDM+Filaria+ individuals showed not only an expansion in the frequency of both Tem2 and Tem17.2 cell subsets, but also a change in their molecular program by overexpressing GATA3, IL17RB, CLRF2, and KLRB1, as well as increased antigen-induced IL-4, IL-5, and IL-13 production, suggesting that aeroallergens reshape the transcriptional and functional programming of Th2 cell subsets in human filarial infection toward a pathogenic immunophenotype.

Thymic stromal lymphopoietin limits primary and recall CD8+ T-cell anti-viral responses

Thymic stromal lymphopoietin (TSLP) is a cytokine that acts directly on CD4+ T cells and dendritic cells to promote progression of asthma, atopic dermatitis, and allergic inflammation. However, a direct role for TSLP in CD8+ T-cell primary responses remains controversial and its role in memory CD8+ T cell responses to secondary viral infection is unknown. Here, we investigate the role of TSLP in both primary and recall responses in mice using two different viral systems. Interestingly, TSLP limited the primary CD8+ T-cell response to influenza but did not affect T cell function nor significantly alter the number of memory CD8+ T cells generated after influenza infection. However, TSLP inhibited memory CD8+ T-cell responses to secondary viral infection with influenza or acute systemic LCMV infection. These data reveal a previously unappreciated role for TSLP on recall CD8+ T-cell responses in response to viral infection, findings with potential translational implications.

Abstract P5-12-04: Directed exercise intervention in breast cancer patients with arthralgias receiving aromatase inhibitors: A randomized pilot study

Purpose: Early discontinuation or non-adherence of AI therapy occurs in 25-50 % of patients due to treatment associated toxicities, including musculoskeletal symptoms such as arthralgias and myalgias. The goal of this pilot study is to evaluate the effect of a directed physical therapy regimen including joint mobility and stretching exercises on musculoskeletal symptoms resulting from AI therapy, in comparison to normal physical activity alone.

Patients and methods: Eligibility criteria included post-menopausal women with histological evidence of hormone receptor positive breast cancer who were currently receiving adjuvant AI therapy and experiencing significant joint discomfort/stiffness when attempting activities of daily living which began or significantly increased after initiation of AI therapy. Patients were excluded if they had preexisting rheumatoid arthritis or fibromyalgia, systemic metastasis or ECOG performance status of greater than 2. Patients were randomly assigned to an 8 week directed exercise program under the supervision of a physical therapist (Group A, n=15) or were told to participate in moderate physical activity (walking) (Group B, n=12). Before beginning the study and at the end of the 8 week intervention, patients in both groups underwent a physical therapy evaluation including performance based measures such as functional lower extremity strength and grip strength and a Patient Specific Functional Scale (PSFS) to assess functional ability to complete specific activities. Additionally, all patients answered a series of questionnaires including a pain disability index (PDI), pain scale (PS) and the PHQ4 depression scale. Effects of the directed exercise regimen were evaluated using non-parametric analysis to determine differences between the two groups.

Results: Significant improvement was observed in both left and right grip strength and right pinch in the intervention group (Group A) as compared to the control group (Group B). Additionally, significant improvement in lower body measures including 2-minute step tests and chair raises were observed in patients who underwent the directed exercise program compared to the control group. No significant differences were observed in PS, PDI or PHQ4 between the groups. However, Group A showed a slight improvement on the PS and PDI.

Conclusions: Directed exercise regimens involving joint mobility and stretching exercises may have benefits over moderate physical activity alone for joint pain and arthralgia associated with AI therapy.

Citation Format: Varadarajan R, Helm E, Arnold C, Huelsenbeck-Dill L, Ingraham-Lopresto B, Sonaad S, Swanson P, Sims-Mourtada J, Dickson-Whitmer D. Directed exercise intervention in breast cancer patients with arthralgias receiving aromatase inhibitors: A randomized pilot study. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P5-12-04.

CNS stromal cells modulate antiviral CD8 T cell immunity (VIR4P.1009)

Lymphocytes are essential for control of neurotropic viruses such as HSV, HIV, and JC virus. Understanding the mechanisms involved in the regulation of these cells is essential for the development of therapeutic interventions to treat central nervous system (CNS) infections. Using two-photon microscopy, we observed that CD8 T cells responding to a viral infection interact with meningeal stromal cells (MSCs), a population of specialized fibroblasts that comprise a dense, collagenous fiber network within the lining of the brain. Little is known about the immunological functions of MSCs. To gain novel insights into these cells, we conducted genomic analyses of purified MSCs at different time points following CNS infection with lymphocytic choriomeningitis virus (LCMV). Our analyses revealed that MSCs responded to virus infection through induction of a robust immunological program that included genes associated with antigen presentation, chemotaxis, immune regulation, among others. We also observed in vivo that MSCs were able to present viral-peptide MHC I complexes, which corroborated our intravital imaging studies showing direct, stable interactions between MSCs and anti-viral T cells. MSCs possess the capacity to regulate these interactions through expression of multiple immune regulators such as PD-L1, galectin-9, and PVR. Our data demonstrate that MSCs are a novel CNS-resident antigen presenting cell with the ability to modulate antiviral T cells following infection.

Metabolic hormones regulate basal and growth hormone-dependent igf2 mRNA level in primary cultured coho salmon hepatocytes: effects of insulin, glucagon, dexamethasone, and triiodothyronine

Igf1 and Igf2 stimulate growth and development of vertebrates. Circulating Igfs are produced by the liver. In mammals, Igf1 mediates the postnatal growth-promoting effects of growth hormone (Gh), whereas Igf2 stimulates fetal and placental growth. Hepatic Igf2 production is not regulated by Gh in mammals. Little is known about the regulation of hepatic Igf2 production in nonmammalian vertebrates. We examined the regulation of igf2 mRNA level by metabolic hormones in primary cultured coho salmon hepatocytes. Gh, insulin, the glucocorticoid agonist dexamethasone (Dex), and glucagon increased igf2 mRNA levels, whereas triiodothyronine (T(3)) decreased igf2 mRNA levels. Gh stimulated igf2 mRNA at physiological concentrations (0.25x10(-9) M and above). Insulin strongly enhanced Gh stimulation of igf2 at low physiological concentrations (10(-11) M and above), and increased basal igf2 (10(-8) M and above). Dex stimulated basal igf2 at concentrations comparable to those of stressed circulating cortisol (10(-8) M and above). Glucagon stimulated basal and Gh-stimulated igf2 at supraphysiological concentrations (10(-7) M and above), whereas T(3) suppressed basal and Gh-stimulated igf2 at the single concentration tested (10(-7) M). These results show that igf2 mRNA level is highly regulated in salmon hepatocytes, suggesting that liver-derived Igf2 plays a significant role in salmon growth physiology. The synergistic regulation of igf2 by insulin and Gh in salmon hepatocytes is similar to the regulation of hepatic Igf1 production in mammals.

Metabolic hormones regulate insulin-like growth factor binding protein-1 mRNA levels in primary cultured salmon hepatocytes; lack of inhibition by insulin

IGF-binding proteins (IGFBPs) modulate the effects of the IGFs, major stimulators of vertebrate growth and development. In mammals, IGFBP-1 inhibits the actions of IGF-I. Rapid increases in circulating IGFBP-1 occur during catabolic states. Insulin and glucocorticoids are the primary regulators of circulating IGFBP-1 in mammals. Insulin inhibits and glucocorticoids stimulate hepatocyte IGFBP-1 gene expression and production. A 22 kDa IGFBP in salmon blood also increases during catabolic states and has recently been identified as an IGFBP-1 homolog. We examined the hormonal regulation of salmon IGFBP-1 mRNA levels and protein secretion in primary cultured salmon hepatocytes. The glucocorticoid agonist dexamethasone progressively increased hepatocyte IGFBP-1 mRNA levels (eightfold) and medium IGFBP-1 immunoreactivity over concentrations comparable with stressed circulating cortisol levels (10(-9) -10(-6) M). GH progressively reduced IGFBP-1 mRNA levels (0.3-fold) and medium IGFBP-1 immunoreactivity over physiological concentrations (5 x 10(-11)-5 x 10(-9) M). Unexpectedly, insulin slightly increased hepatocyte IGFBP-1 mRNA (1.4-fold) and did not change medium IGFBP-1 immunoreactivity over physiological concentrations and above (10(-9) -10(-6) M). Triiodothyronine had no effect on hepatocyte IGFBP-1 mRNA, whereas glucagon increased IGFBP-1 mRNA (2.2-fold) at supraphysiological concentrations (10(-6) M). This study suggests that the major inhibitory role of insulin in the regulation of liver IGFBP-1 production in mammals is not found in salmon. However, regulation of salmon liver IGFBP-1 production by other metabolic hormones is similar to what is found in mammals.

Panitumumab antitumor activity in patients (pts) with metastatic colorectal cancer (mCRC) expressing ≥ 10% epidermal growth factor receptor (EGFr)

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Background: Panitumumab is a fully human monoclonal antibody directed against EGFr. We investigated panitumumab antitumor activity in pts who failed prior therapy and had EGFr tumor expression levels ≥ 10%. Methods: In this multicenter, phase 2 study of 300 planned pts, pts had documentation of disease progression (PD) during or following adequate doses of fluoropyrimidine, irinotecan, and oxaliplatin (centrally confirmed refractory disease [CCRD]), 2–3 prior regimens, ECOG score 0–2, and EGFr staining (by IHC) in ≥ 10% of evaluable tumor cells. Pts received panitumumab at 6 mg/kg Q2W until PD. Tumor assessments (modified WHO, blinded central review) were taken periodically from wk 8–48 until PD. Study endpoints were objective response rate (ORR) at wk 16 (+ ≥ 4 wk confirmation; primary) and ORR throughout study, response duration, progression-free survival (PFS) time, survival time, and safety (secondary). Results: In this interim analysis (5/05), 91 enrolled pts received ≥ 1 dose of panitumumab (safety set); 39 had ≥ 20 wks before the cutoff and CCRD (efficacy set). The efficacy set consisted of 23M/16W, mean (SD) age of 58.6 (10.1) years, 82% white, 95% ECOG ≤ 1, 74% colon cancer and 26% rectal cancer; all had ≥ 2 prior regimens (equivalent characteristics for safety set). At wk 16, 3 (8%) had a partial response, 8 (21%) had stable disease, and 19 (49%) had PD as best OR (9 not done/unevaluable). At the time of this interim analysis, response durations were 12.4, 13.2, and 14.0 wks. In the safety set, 96% had at least 1 treatment-related adverse event (24% grade [gr] 3, 1% gr 4, 1% gr 5). Integument and eye toxicities were: 96% skin, 30% nail, 8% eye, 5% hair, and 7% chelitis. 25 (27%) had diarrhea (3 gr 3); 11 (12%) had hypomagnesemia (3 gr 3/4). One pt had a gr 3 hypersensitivity reaction considered related to panitumumab, received medication, and the event resolved; this pt continued treatment with premedication; no further reactions occurred. In 66 pts with both a baseline and postdose sample, no human anti-human antibodies to panitumumab were detected.Additional data will be presented. Conclusions: Panitumumab has antitumor activity and is well tolerated in pts with EGFr tumor expression levels ≥ 10% who failed standard chemotherapy.

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Changes in mRNAs encoding steroidogenic acute regulatory protein, steroidogenic enzymes and receptors for gonadotropins during spermatogenesis in rainbow trout testes

In vertebrates, sperm development and maturation are directly regulated by gonadal steroid hormone secretion. The relationships among the expression of genes encoding steroidogenic proteins and receptors for gonadotropins, and testicular steroid production have not yet been comprehensively determined in male teleosts. In this study, the changes in levels of mRNAs encoding follicle-stimulating hormone (FSH) receptor, luteinizing hormone (LH) receptor, steroidogenic acute regulatory protein (StAR), cytochrome P450 cholesterol side-chain cleavage, 3beta-hydroxysteroid dehydrogenase/delta5-4-isomerase, cytochrome P450 17alpha-hydroxylase/17,20-lyase, cytochrome P450 11beta-hydroxylase, 11beta-hydroxysteroid dehydrogenase and 20beta-hydroxysteroid dehydrogenase were determined by real-time, quantitative PCR assays and related to changes in serum steroid levels throughout the reproductive cycle in male rainbow trout. Serum 11-ketotestosterone and 17alpha,20beta-dihydroxy-4-pregnen-3-one levels were measured by RIA. Although the pattern of change in the mRNA levels for the enzymes was variable, the increases in steroidogenic enzyme mRNAs started prior to a significant increase of serum steroid levels. The patterns of transcript levels of FSH and LH receptors suggest that changes in StAR and steroidogenic enzyme transcripts are largely mediated by the FSH receptor during early and mid-spermatogenesis and by the LH receptor during late spermatogenesis and spermiation. Levels of StAR (10-fold) and P450 17alpha-hydroxylase/17,20-lyase (sevenfold) transcripts changed with the greatest magnitude and were closely related to the changes in serum steroids, suggesting that changes in StAR and P450 17alpha-hydroxylase/17,20-lyase abundance are likely to be the major influences on overall steroidogenic output during the reproductive cycle in male rainbow trout.

Previtellogenic oocyte growth in salmon: relationships among body growth, plasma insulin-like growth factor-1, estradiol-17beta, follicle-stimulating hormone and expression of ovarian genes for insulin-like growth factors, steroidogenic-acute regulatory protein and receptors for gonadotropins, growth hormone, and somatolactin

Body growth during critical periods is known to be an important factor in determining the age of maturity and fecundity in fish. However, the endocrine mechanisms controlling oogenesis in fish and the effects of growth on this process are poorly understood. In this study interactions between the growth and reproductive systems were examined by monitoring changes in various components of the FSH-ovary axis, plasma insulin-like growth factor 1 (Igf1), and ovarian gene expression in relation to body and previtellogenic oocyte growth in coho salmon. Samples were collected from females during two hypothesized critical periods when growth influences maturation in this species. Body growth during the fall-spring months was strongly related to the degree of oocyte development, with larger fish possessing more advanced oocytes than smaller, slower growing fish. The accumulation of cortical alveoli in the oocytes was associated with increases in plasma and pituitary FSH, plasma estradiol-17beta, and ovarian steroidogenic acute regulatory protein (star) gene expression, whereas ovarian transcripts for growth hormone receptor and somatolactin receptor decreased. As oocytes accumulated lipid droplets, a general increase occurred in plasma Igf1 and components of the FSH-ovary axis, including plasma FSH, estradiol-17beta, and ovarian mRNAs for gonadotropin receptors, star, igf1, and igf2. A consistent positive relationship between plasma Igf1, estradiol-17beta, and pituitary FSH during growth in the spring suggests that these factors are important links in the mechanism by which body growth influences the rate of oocyte development.

Genotypes of Cryptosporidium from Sydney water catchment areas

AIMS

Currently cryptosporidiosis represents the major public health concern of water utilities in developed nations and increasingly, new species and genotypes of Cryptosporidium are being identified in which the infectivity for humans is not clear. The complicated epidemiology of Cryptosporidium and the fact that the majority of species and genotypes of Cryptosporidium cannot be distinguished morphologically makes the assessment of public health risk difficult if oocysts are detected in the raw water supplies. The aim of this study was to use molecular tools to identify sources of Cryptosporidium from the Warragamba catchment area of Sydney, Australia.

METHODS AND RESULTS

Both faecal and water samples from the catchment area were collected and screened using immunomagnetic separation (IMS) and immunofluorescence microscopy. Samples that contained Cryptosporidium oocysts were genotyped using sequence and phylogenetic analysis of the 18S rDNA, and the heat-shock (HSP-70) gene. Analysis identified five Cryptosporidium species/genotypes including C. parvum (cattle genotype), C. suis, pig genotype II, the cervid genotype and a novel goat genotype.

CONCLUSIONS

Monitoring and characterization of the sources of oocyst contamination in watersheds will aid in the development and implementation of the most appropriate watershed management policies to protect the public from the risks of waterborne Cryptosporidium.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study has shown that quantification by IMS analysis can be combined with the specificity of genotyping to provide an extremely valuable tool for assessing the human health risks from land use activities in drinking water catchments.

Pesticides and Risk of Parkinson Disease

BACKGROUND

Pesticide exposures are suspected risk factors for Parkinson disease (PD), but epidemiological observations have been inconsistent.

OBJECTIVE

To investigate associations between pesticide exposures and idiopathic PD.

DESIGN

Population-based case-control study.

SETTING

Group Health Cooperative, a health care system in western Washington State, and the University of Washington.

PARTICIPANTS

Two hundred fifty incident PD case patients and 388 healthy control subjects (age- and sex-matched). We assessed self-reported pesticide exposures using a structured interview. Odds ratios (ORs) and 95% confidence intervals (CIs) were determined using logistic regression models, controlling for age, sex, and smoking.

RESULTS

Odds ratios for occupational exposures were not significant but suggested a gradient that paralleled occupational exposures (pesticide worker: OR, 2.07; 95% CI, 0.67-6.38; crop farmer: OR, 1.65; 95% CI, 0.84-3.27; animal and crop farmer: OR, 1.10; 95% CI, 0.60-2.00; and dairy farmer: OR, 0.88; 95% CI, 0.46-1.70). Odds ratios for organophosphates paralleled the World Health Organization hazard classifications, with parathion much higher than diazinon or malathion. We also found elevated ORs from herbicides (OR, 1.41; 95% CI, 0.51-3.88) and paraquat (OR, 1.67; 95% CI, 0.22-12.76). We found no evidence of risk from home-based pesticide exposures. We found significantly increased ORs from lifelong well water consumption (OR, 1.81; 95% CI, 1.02-3.21).

CONCLUSIONS

The findings for occupational pesticide exposures are consistent with a growing body of information linking pesticide exposures with PD. However, the lack of significant associations, absence of associations with home-based exposures, and weak associations with rural exposures suggest that pesticides did not play a substantial etiologic role in this population.

A quantitative real-time RT-PCR assay for salmon IGF-I mRNA, and its application in the study of GH regulation of IGF-I gene expression in primary culture of salmon hepatocytes

The hormone insulin-like growth factor-I (IGF-I) regulates vertebrate growth. The liver produces most circulating IGF-I, under the control of pituitary growth hormone (GH) and nutritional status. To study the regulation of liver IGF-I production in salmon, we established a primary hepatocyte culture system and developed a TaqMan quantitative real-time RT-PCR assay for salmon IGF-I gene expression. A portion of the coho salmon acidic ribosomal phosphoprotein P0 (ARP) cDNA was sequenced for use as a reference gene. A systematic bias across the 96 well PCR plate was discovered in an initial IGF-I assay, which was corrected when the assay was redesigned. IGF-I mRNA levels measured with the validated assay correlated well with levels measured with an RNase protection assay, and were highest in liver compared with other tissues. We examined the time course of hepatocyte IGF-I gene expression over 48 h in culture, the response to a range of GH concentrations in hepatocytes from fed and fasted fish, and potential effects of variation in IGF-I in the medium. IGF-I gene expression decreased over time in culture in hepatocytes in plain medium, and in cells treated with 5 nM GH with or without a combination of metabolic hormones (1 microM insulin, 100 nM triiodothyronine, and 0.1 nM dexamethasone). GH stimulated IGF-I gene expression at all time points. In cells treated with GH plus metabolic hormones, IGF-I gene expression was intermediate between the controls and GH alone. Increasing concentrations of GH resulted in biphasic IGF-I gene expression response curves in cells from fed and fasted fish, with the threshold for stimulation from 0.5 to 2.5 nM GH, maximal response from 5 to 50 nM, and a reduced response at 500 nM. Medium IGF-I (5 nM) did not affect basal or GH stimulated IGF-I gene expression. This study shows that primary hepatocyte culture and the TaqMan IGF-I assay can be used to study the regulation of hepatic IGF-I gene expression in salmon, and provides the first evidence of a biphasic response to GH concentration in fish hepatocyte culture.

Endocrine changes during onset of puberty in male spring Chinook salmon, Oncorhynchus tshawytscha

In male salmonids, the age of maturation varies from 1 to 6 years and is influenced by growth during critical periods of the life cycle. The endocrine mechanisms controlling spermatogenesis and how growth affects this process are poorly understood. Recent research has indicated that gonadotropins, 11-ketotestosterone, and insulin-like growth factor I play roles in spermatogenesis in fish. To expand our understanding of the roles of these endocrine factors in onset of puberty, male spring chinook salmon (Oncorhynchus tshawytscha) were sampled at monthly intervals 14 mo prior to spermiation. This sampling regime encompassed two hypothesized critical periods when growth influences the initiation and completion of puberty for this species. Approximately 80% of the males matured during the experimental period, at age 2 in September 1999. An initial decline in the ratio of primary A to transitional spermatogonia was observed from July to December 1998, and during this period plasma levels of 11-ketotestosterone and pituitary levels of FSH increased. From January 1999 onward, males with low plasma 11-ketotestosterone levels (<1 ng/ml) had low pituitary and plasma FSH levels and no advanced development of germ cells. Conversely, from January through September 1999, males with high plasma 11-ketotestosterone levels (>1 ng/ml) had testes with progressively more advanced germ cell stages along with elevated pituitary and plasma FSH. Plasma levels of insulin-like growth factor I increased during maturation. These data provide the first physiological evidence for activation of the pituitary-testis axis during the fall critical period when maturation is initiated for the following year.

Age at onset of Parkinson disease and apolipoprotein E genotypes

Several lines of evidence suggest that the variable age at onset of Parkinson disease (PD) is likely influenced by genes. The apolipoprotein E (APOE) gene is associated with onset of Alzheimer disease, and possibly other neurodegenerative disorders. APOE has been investigated in relation to onset of PD, but results have been inconsistent. The aim of the present study was to determine if APOE genotypes are associated with onset age of PD, using a patient population large enough to assure sufficient power. We studied 521 unrelated Caucasian patients with idiopathic PD from movement disorder clinics in Oregon and Washington. Genotyping and statistical analyses were carried out using standard methods. Age at onset of PD was significantly earlier in patients with the varepsilon3varepsilon4/varepsilon4varepsilon4 genotype than in patients with the varepsilon3varepsilon3 genotype (56.1 +/- 10.9 vs. 59.6 +/- 11.0, P = 0.003). The significantly earlier onset of PD was not influenced by the possible effects of recruitment site, family history and gender. The effect of the varepsilon2varepsilon3 genotype on onset of PD differed between the two recruitment sites. There was a trend for earlier onset of PD in varepsilon2varepsilon3 patients than in varepsilon3varepsilon3 patients only in the Oregon sample. In conclusion, APOE is associated with age at onset of PD.

Biochemical and functional analysis of a conserved IGF-binding protein isolated from rainbow trout (Oncorhynchus mykiss) hepatoma cells

Rainbow trout (Oncorhynchus mykiss) serum contains several IGF-binding proteins (IGFBPs) that specifically bind to IGFs. The structures of these fish IGFBPs have not been determined and their physiological functions are poorly defined. In this study, we identified a 30 kDa IGFBP present in rainbow trout serum and secreted by cultured trout hepatoma cells. This IGFBP binds to IGFs but not to insulin. This IGFBP was purified to homogeneity using a three-step procedure involving Phenyl-Sepharose chromatography, IGF-I affinity chromatography and reverse-phase HPLC. Affinity cross-linking studies indicated that this IGFBP binds to IGF-I with a higher affinity than to IGF-II. N-terminal sequence analysis of the trout IGFBP suggests that it shares high sequence identity with that of human IGFBP-1 in the N-terminal region. When added to cultured fish and human cells, the trout IGFBP inhibited IGF-I-stimulated DNA synthesis and cell proliferation in a concentration-dependent manner. The inhibitory effect of the fish IGFBP was comparable to those of human IGFBP-1 and -4. These results indicate that the IGFBP molecule is structurally and functionally conserved in evolutionarily ancient vertebrate species such as bony fish.

Comparative performance of three viral load assays on human immunodeficiency virus type 1 (HIV-1) isolates representing group M (subtypes A to G) and group O: LCx HIV RNA quantitative, AMPLICOR HIV-1 MONITOR version 1.5, and Quantiplex HIV-1 RNA version 3.0

The performance of the LCx HIV RNA Quantitative (LCx HIV), AMPLICOR HIV-1 MONITOR version 1.5 (MONITOR v1.5), and Quantiplex HIV-1 RNA version 3.0 (bDNA v3.0) viral load assays was evaluated with 39 viral isolates (3 A, 7 B, 6 C, 4 D, 8 E, 4 F, 1 G, 4 mosaic, and 2 group O). Quantitation across the assay dynamic ranges was assessed using serial fivefold dilutions of the viruses. In addition, sequences of gag-encoded p24 (gag p24), pol-encoded integrase, and env-encoded gp41 were analyzed to assign group and subtype and to assess nucleotide mismatches at primer and probe binding sites. For group M isolates, quantification was highly correlated among all three assays. In contrast, only the LCx HIV assay reliably quantified group O isolates. The bDNA v3.0 assay detected but consistently underquantified group O viruses, whereas the MONITOR v1.5 test failed to detect group O viruses. Analysis of target regions revealed fewer primer or probe mismatches in the LCx HIV assay than in the MONITOR v1.5 test. Consistent with the high level of nucleotide conservation is the ability of the LCx HIV assay to quantify efficiently human immunodeficiency virus type 1 group M and the genetically diverse group O.

Cloning and functional expression of a thyrotropin receptor from the gonads of a vertebrate (bony fish): potential thyroid-independent role for thyrotropin in reproduction

The thyroid stimulating hormone receptor (TSHR) mediates the pituitary control of the development, growth and function of the thyroid. The expression of the gene encoding this receptor is known only in the thyroid, lymphocytes, fibroblasts, retro-orbital tissue and fat cells. We have cloned a TSHR from the gonads of a non-mammalian vertebrate, a bony fish (striped bass, Morone saxatilis) in the course of our search for gonadotropin receptors (follicle stimulating hormone receptor, FSHR and luteinizing hormone receptor, LHR). RT-PCR analysis demonstrated that the striped bass TSHR (stbTSHR) transcripts were abundant in both the thyroid and gonads and detectable in skeletal muscle, heart and brain tissues. The stbTSHR cDNA encoded a 779-amino acid glycoprotein hormone receptor with much higher homology (57-59%) to the mammalian TSH receptors than the mammalian LH receptors (47-49%) and FSH receptors (47%), and salmon and catfish gonadotropin receptors (42-45%). There was a TSHR-specific insertion in the extracellular domain as seen in mammalian receptors. Moreover, PCR analysis of genomic DNA indicated the absence of the LHR-specific intron in the striped bass TSHR gene. Recombinant stbTSHR expressed in COS1 cells activated reporter genes (luciferase) driven by either a cAMP response element or the c-fos promoter in response to bovine TSH, stbLH or hCG, but not human FSH. In situ hybridization studies revealed the presence of stbTSHR transcripts in the gametes but not in the follicular cells. This pattern of expression is unique and suggests a direct, albeit unknown, role for TSH in gamete physiology.

Insulin-like growth factor I increases follicle-stimulating hormone (FSH) content and gonadotropin-releasing hormone-stimulated FSH release from coho salmon pituitary cells in vitro

The effects of insulin-like growth factor I (IGF-I) and insulin on the function of coho salmon gonadotropes in vitro were investigated. Dispersed pituitary cells from immature coho salmon (Oncorhynchus kisutch) were incubated with IGF-I for 1, 3, 7, or 10 days, then incubated with salmon GnRH for an additional 24 h. Medium FSH content before and after GnRH treatment and intracellular FSH content after GnRH treatment were measured. Incubation of pituitary cells with IGF-I for 7 or 10 days increased GnRH-stimulated FSH release and remaining cell content, but did not affect basal release. To examine the specificity of the effects of IGF-I, we compared FSH release and cell content of FSH and LH after 10-day incubation with a range of concentrations of IGF-I or insulin. Incubation with physiological concentrations of IGF-I resulted in significantly higher GnRH-stimulated FSH release and remaining cell content of FSH and LH. Conversely, supraphysiological concentrations of insulin were required to produce more moderate effects on gonadotropin levels. These results suggest that elevation of gonadotropin levels by IGF-I may be one mechanism by which somatic growth and nutrition promote pubertal development in salmon.

Quantification of HIV-1 group M (subtypes A-G) and group O by the LCx HIV RNA quantitative assay

Human immunodeficiency virus type 1 (HIV-1) genetic diversity presents a challenge to nucleic acid-based assays with regard to sensitivity of detection and accuracy of quantification. The Abbott LCx HIV RNA Quantitative assay (LCx(R) HIV assay), a competitive RT-PCR targeting the pol integrase region, was evaluated using a panel of 297 HIV-1 seropositive plasma samples from Cameroon, Uganda, Brazil, Thailand, Spain, Argentina and South Africa. The panel included group M subtypes A-G, mosaics, and group O based on sequence analysis of gag p24, pol integrase, and env gp41. The LCx HIV assay quantified 290 (97.6%) of the samples, including all the group O samples tested. In comparison, the Roche AMPLICOR HIV-1 MONITOR test versions 1.0 and 1.5 quantified 67.3 and 94.6% of the samples, respectively. No group O specimens were quantified by either version of AMPLICOR HIV-1 MONITOR. Seven specimens were below the detectable limits of all the three assays. The LCx HIV assay had fewer nucleotide mismatches at primer/probe binding sites as compared with both AMPLICOR HIV-1 MONITOR tests. The high degree of nucleotide conservation within the pol target region enables the LCx HIV assay to efficiently quantify the HIV-1 subtypes A-G and the most genetically diverse HIV-1, group O.

Comparison of extraction methods and assay validation for salmon insulin-like growth factor-I using commercially available components

Insulin-like growth factor-binding proteins (IGFBPs) may interfere with accurate measurement of plasma IGFs in radioimmunoassay (RIA). Although several simplified extraction methods for IGFs have been developed, these methods are not always validated for differing physiological states, developmental stages, and animal species. For teleost fish, neither the necessity of plasma extraction nor the validity of extraction methods for IGF RIA is widely established. We systematically examined the validity of acid-ethanol (AE) extraction, AE extraction followed by cryoprecipitation (AEC extraction), and SP-Sephadex extraction in RIA for salmon IGF-I using commercially available components (GroPep Pty Ltd). Displacement curves of plasma extracted by AE, AEC, and SP-Sephadex were parallel to those of the standard. Measured IGF-I levels in plasma from several developmental stages and under different physiological and experimental conditions were significantly increased by the extractions and comparable to those after acid-size exclusion chromatography (SEC). On Western ligand blotting using digoxigenin-labeled human IGF-I, the intensity of IGFBP bands remaining in plasma were reduced after extraction, although some IGFBPs remained. However, these residual IGFBPs did not interfere measurably with the RIA based on quantitative comparison of IGF-I levels with acid-SEC. We conclude that with this RIA extraction is necessary for measurement of salmon IGF-I in plasma since measured values were routinely lower in unextracted samples, and AE, AEC, and SP-Sephadex extractions are applicable to the IGF-I RIA using the commercially available components. Using the validated RIA for IGF-I, plasma IGF-I levels in nonmaturing and precociously maturing chinook salmon in spring were measured after AE extraction. During spring, nonmaturing and maturing fish fed and grew well, and plasma IGF-I level was significantly correlated with body weight in both fish. This result indicates that circulating IGF-I plays a key role in controlling growth in precociously maturing chinook salmon in spring as in nonmaturing fish.

Effects of salmon gonadotropin-releasing hormone on follicle stimulating hormone secretion and subunit gene expression in coho salmon (Oncorhynchus kisutch)

Previous work has indicated that, during the process of gametogenesis in salmon, follicle-stimulating hormone (FSH) and luteinizing hormone (LH) are differentially synthesized and released. Although substantial information is available on the regulation of LH in many fish species, relatively little is known about the regulation of FSH biosynthesis and secretion or the regulation of two types of alpha subunit in salmon. In this study, the effects of salmon gonadotropin-releasing hormone (sGnRH) on in vitro secretion of FSH, and alpha1, alpha2, LH beta, and FSH beta subunit gene expression were investigated in coho salmon (Oncorhynchus kisutch) using primary pituitary cell cultures. To quantify FSH beta, LH beta, alpha1, and alpha2 subunit transcript levels, a multiplex RNase protection assay (RPA) was developed. Probes for the beta subunits of coho salmon FSH and LH were available from previous studies. To generate probes for the alpha subunit RPAs, alpha1 and alpha2 subunit cDNAs were cloned using reverse transcriptase PCR. Release of FSH and LH into cell culture medium was quantified by radioimmunoassays. The effects of sGnRH on gonadotropin release and gene expression were tested at two points during the spring (April and May) prior to spawning in the autumn; a period when plasma and pituitary FSH levels are increasing and females are in early stages of secondary oocyte growth. In both experiments, sGnRH increased steady-state mRNA levels of FSH beta, alpha1, and alpha2, whereas LH beta mRNA levels were not detectable. Secretion of FSH was stimulated by sGnRH in a concentration-dependent manner. Medium LH was not detectable in the first experiment (April) and was measurable only after sGnRH treatment in the second experiment (May). Control levels of medium FSH and transcripts for FSH beta and alpha1 subunits increased approximately fourfold between April and May, whereas alpha2 transcript levels remained relatively constant, suggesting that the seasonal increase in FSH release may involve increased production of alpha1. Therefore, sGnRH has direct stimulatory effects on both secretion of FSH and FSH subunit biosynthesis, most likely due to increased transcription. However, alterations in rates of transcript degradation cannot be ruled out.

Regulation of ovarian steroidogenesis in vitro by follicle-stimulating hormone and luteinizing hormone during sexual maturation in salmonid fish

The regulation of ovarian steroidogenesis in vitro by coho salmon FSH and LH was investigated in intact coho salmon follicles and isolated follicular layers at various stages of oocyte maturation, from late vitellogenesis until the completion of germinal vesicle breakdown (GVBD). In granulosa layers from all stages, LH, but not FSH, stimulated 17alpha,20beta-dihydroxy-4-pregnen-3-one (17, 20beta-P) production. In theca-interstitial layers from all stages, FSH and LH stimulated steroid production, LH being more potent than FSH. The basal steroid output of intact follicles was significantly lower than that of isolated follicular layers, and their response to FSH and LH also differed. First, the intact follicles produced 17alpha-hydroxyprogesterone in response to FSH during the central germinal vesicle stage while theca-interstitial layers did not. Second, estradiol-17beta production was not inhibited by LH during final oocyte maturation in intact follicles, as observed for granulosa layers. Our results indicate that LH is the determining factor regulating the production of the maturation-inducing steroid, 17,20beta-P, and the induction of GVBD in the salmonid ovary. In summary, we have provided evidence for maturation-associated changes in the effects of FSH and LH in the salmonid ovary, which further supports the hypothesis that FSH and LH have distinct functions in the teleost ovary.

Long-term peripheral treatment of immature coho salmon (Oncorhynchus kisutch) with human leptin has no clear physiologic effect

The effects of long-term peripheral exposure to recombinant human leptin were tested in immature coho salmon under both fed and fasted conditions. We found that high circulating levels of human leptin did not alter growth, energy stores, gonad weight, pituitary content of follicle-stimulating hormone, or plasma levels of insulin-like growth factor-I, insulin, growth hormone, or thyroxine.

Denudations as paracellular routes for alphafetoprotein and creatinine across the human syncytiotrophoblast

We tested two hypotheses: 1) that fibrin-containing fibrinoid-filled denudations of the syncytiotrophoblast may provide a route for paracellular diffusion and 2) that placentas from women who had elevated maternal serum alphafetoprotein (MSAFP) in midgestation had raised permeability to AFP and greater denudation than in normal pregnancy. We measured AFP and creatinine clearance across term placental cotyledons from the above groups and used light microscope morphometric analysis to determine the volume density of fibrin-containing fibrinoid deposits. There was no significant difference between the two groups in terms of AFP and creatinine clearance or volume density of fibrin-containing fibrinoid deposits. The combined data showed a significant (P < 0.05) positive correlation between creatinine clearance, but not AFP clearance, and volume density of fibrin-containing fibrinoid. We conclude that syncytiotrophoblast denudations, with associated fibrinoid, do provide a route for diffusion of small hydrophilic solutes, but that other anatomic features of the placenta are rate limiting for transfer of AFP and similarly sized molecules.

Purification, characterization, and bioassay of prolactin and growth hormone from temperate basses, genus Morone

Prolactin (PRL) and two variants of growth hormone (GH), purified from pituitaries of striped bass (Morone saxatilis) and its hybrid with white bass (M. saxatilis x M. chrysops) by gel filtration chromatography under alkaline conditions followed by reversed-phase high pressure liquid chromatography, appear similar between species. Both the minor (GH I) and the major (GH II) forms of purified GH appeared as single bands (M(r) approximately 23,000) after sodium dodecyl sulfate-polyacrylamide gel electrophoresis, as did the purified PRL (M(r) approximately 24,000). The molecular weights of GH II and PRL determined by MALDI TOF mass spectroscopy were 21.2 and 21.3 kDa, respectively. In Western blotting experiments, an antiserum against tilapia (Oreochromis mossambicus) 24K PRL specifically recognized Morone PRL, while an antiserum against tilapia GH specifically recognized Morone GH I and II. Chemical identities of the putative PRL and GH I were further confirmed by N-terminal peptide sequencing, while internal sequence analysis was performed on GH II because it was blocked at its N-terminus. Over a stretch of 29 amino acids, Morone PRL was found to be 76% identical to tilapia 24K PRL, 72% identical to tilapia 20K PRL, 72% identical to chum salmon (Oncorhynchus keta) PRL I, and 69% identical to eel (Anguilla japonica) PRL I. Alignment of the hybrid striped bass GH sequences with those of several other advanced marine teleosts indicated 75-85% sequence identity for GH I (40 amino acids) and 95-98% identity for GH II (45 amino acids). Biological activity of striped bass GH II was confirmed using a heterologous in vitro assay of insulin-like growth factor I mRNA production by coho salmon (On. kisutch) hepatocytes. An in vivo bioassay, involving hypophysectomy of hybrid striped bass and treatment of the fish maintained in fresh water with homologous PRL, confirmed that the purified striped bass PRL was also bioactive.

Primary gastric plasmacytoma: a rare cause of hypertrophic gastritis in an adolescent

BACKGROUND

This report describes a 16-year-old patient with gastric rugal hypertrophy caused by a primary gastric plasmacytoma. She had a 3-month history of nausea and burning abdominal pain. Radiographic studies showed giant rugal hypertrophy. Superficial endoscopic gastric biopsies showed mild inflammation with plasma cells of polyclonal origin in the mucosa. When symptoms persisted, she underwent laparoscopic full-thickness gastric biopsy. There was monoclonal plasma cell infiltration histologically diagnostic of plasmacytoma and inconsistent with Helicobacter pylori-associated mucosa-associated lymphoid tissue (MALT) lymphoma. There was no evidence for involvement of the bone marrow or regional lymph nodes. The tumor did not respond to radiotherapy, necessitating total gastrectomy.

METHODS

Blood samples were analyzed for interleukin (IL)-6 by enzyme-linked immunosorbent assay. Gastric biopsy and gastrectomy specimens were subjected to immunophenotyping for kappa and lambda light chains, CD45, CD20, and LN1 and to polymerase chain reaction analysis for herpes virus HHV8.

RESULTS

There was no elevation in circulating IL-6 levels, militating against a pathogenesis akin to that of Castleman's disease. There was no evidence for infection with the Kaposi's sarcoma-associated herpes virus HHV8, which has recently been found in patients with multiple myeloma.

CONCLUSIONS

This diagnosis and the characteristics of the tumor are very unusual, if not unique, for a patient of this age. The diagnostic evaluation of this patient also demonstrates the importance of deep endoscopic or full-thickness biopsies in some children with hypertrophic gastritis.

Effects of testosterone on gonadotropins, testes, and plasma 17alpha,20beta-dihydroxy-4-pregnene-3-one levels in postbreeding mature Atlantic salmon, Salmo salar, male parr

Atlantic salmon, Salmo salar, mature male parr were implanted with testosterone (T) in small (T3) or large (T10) Silastic capsules in the breeding season or at its end in November or December, in order to find out whether the postbreeding decline in 17alpha, 20beta-dihydroxy-4-pregnene-3-one (17,20beta-P) and milt production is a consequence of declining T levels. In the first of three experiments, fish were sampled the following January and March, whereas in the second and in the third they were sampled in April. Pituitary and plasma concentrations of gonadotropic hormone (GTHs) I and II and plasma levels of T, 11-ketotestosterone (11-KT) and 17, 20beta-P were measured by radioimmunoassays, and the testes were examined histologically. Administration of T prolonged the period in which running milt was present, suppressed Sertoli cells, and prevented the postbreeding decline in testes weight in experiment two. The postbreeding decline in plasma 17,20beta-P levels was diminished by T10 in experiment one, and by both T3 and T10 in experiment two. The similar decline in 11-KT levels was not influenced by T treatment (only studied in experiment one). T treatment also prevented a decline in pituitary GTH II content (in experiments two and three) and in plasma GTH II levels (only studied in experiment three). However, pituitary GTH I content was not influenced (experiment two and three), whereas plasma GTH I levels (only studied in experiment three) were suppressed by T. To summarize, T treatment prevents postbreeding decline in 17,20beta-P levels, probably via a stimulation of GTH II secretion. J. Exp. Zool. 284:425-436, 1999.

Free and protein-bound insulin-like growth factor-I (IGF-I) and IGF-binding proteins in plasma of coho salmon, Oncorhynchus kisutch

Total and free insulin-like growth factor-I (IGF-I) levels were quantified in plasma from growth hormone (GH)-treated and fasted coho salmon. Total IGF-I was measured by radioimmunoassay after acid-ethanol extraction and free IGF-I was separated from protein-bound IGF-I using ultrafiltration by centrifugation. Total and free IGF-I increased in plasma after GH treatment and decreased after fasting. The level of free IGF-I, however, was maintained at approximately 0.3% in both experiments. Unsaturated binding activity in plasma for IGF-I was assessed by incubation with (125)I-recombinant salmon IGF-I ((125)I-sIGF-I). Although there was no difference in binding activity between GH-treated and control fish, fasted fish showed higher binding activity than did fed fish, suggesting induction of unsaturated binding protein by fasting. IGF-binding protein (IGFBP) bands were observed in plasma of coho salmon by Western ligand blotting using (125)I-sIGF-I. A low-molecular-weight (22 kDa) band was clear in fasted fish but not detectable in fed fish. The IGFBP band, which has molecular weight similar to that of human IGFBP-3 (41 kDa), was more intense in GH-treated fish than in controls. The molecular distribution of IGF-I in plasma was examined by gel filtration under neutral conditions. Most IGF-I was eluted around 40 kDa. This result suggests that the major form of bound IGF-I in the circulation of coho salmon may be in a 40-kDa binary complex rather than in a 150-kDa ternary complex, as in mammals.

The brain-pituitary-gonadal axis of female rainbow trout Oncorhynchus mykiss: effects of photoperiod manipulation1

Two groups of post-spawned female rainbow trout were exposed to two different photoperiods, an ambient photoperiod (56 degrees N) and a combination of long and short photoperiods (a constant 18L:6D from February 1 until May 10, then a constant 6L:18D), which acted to advance maturation and spawning. The stimulatory long-short photoperiod advanced spawning by 3-4 months and correspondingly advanced peaks in serum levels of 17beta-estradiol, testosterone, calcium (an index of vitellogenin), and GTH II. Earlier events in gonadal recrudescence appeared to be less affected by the photoperiod. The initiation of exogenous vitellogenesis coincided with high levels of both pituitary salmon gonadotropin-releasing hormone (sGnRH) content and serum follicle-stimulating hormone (FSH, GTH I) levels. High levels of serum FSH were associated with rapid gonadal growth in the fish exposed to the stimulatory long-short photoperiod. In contrast, the fish exposed to the ambient photoperiod showed gonadal steroid production, formation of vitellogenin, and secondary oocyte growth without any detectable increase in serum FSH levels. The possible roles and interactions of sGnRH, gonadotropins, and steroids with respect to normal and artificially stimulated ovarian maturation are discussed.

Feedback control of gonadotropins in Atlantic salmon, Salmo salar, male parr.I. Castration effects in rematuring and nonrematuring fish

Sexual maturation of Atlantic salmon (Salmo salar) male parr is a seasonally recurrent "all or none" response; either a fish matures fully or it does not mature. To study whether gonadal feedback on gonadotropic hormones, GTH I and GTH II, is involved in the control of maturation, previously mature Atlantic salmon male parr were either sham-operated or castrated in spring. They were then sampled during the onset of gonadal growth (late June-early July) or shortly before the breeding season (late September). In autumn, sham-operated males separated into two groups: nonrematuring males with low pituitary and plasma levels of both GTH I and GTH II, and those rematuring with high levels of gonadotropins. Castrated males had low GTH I and GTH II plasma and pituitary levels, similar to those of the nonrematuring fish, suggesting positive feedback mechanisms, separating the sham-operated fish into low and high GTH level groups. In the summer, plasma GTH II was nondetectable in all fish. Pituitary GTH II content was lower in nonrematuring, than in rematuring males and was even lower in castrated fish. In contrast, castration increased pituitary and plasma levels of GTH I in the summer, suggesting a negative feedback at this reproductive stage. There were no significant differences in immunoassayable levels of GTH I in plasma in rematuring and nonrematuring sham-operated males at this time. The control of rematuration is complex and may involve factors other than circulating GTH I levels, possibly with differences in gonadal sensitivity to GTH I.

Feedback control of gonadotropins in Atlantic salmon, Salmo salar, male parr.II. Aromatase inhibitor and androgen effects

Both positive and negative feedback on the (hypothalmus)- pituitary-gonad axis occur in salmonids. The aim of the present study was to investigate the role of different androgens, and in particular the involvement of aromatization of androgens to estrogens in feedback mechanisms. Previously mature Atlantic salmon, Salmo salar, male parr were studied in two experiments. In the first experiment, intact fish were implanted with Silastic capsules filled with the aromatase inhibitor 1,4,6-androstatriene-3,17-dione (ATD) in spring and sampled in the autumn when the rematuring males were starting to display running milt. In the second experiment, castrated males were implanted with capsules containing ATD, the androgens testosterone (T) and 11-ketoandrostenedione (11KA), or ATD and T combined in spring. These fish were sampled in the summer when rematuring fish were starting to show signs of gonadal growth. Pituitary and plasma gonadotropins (GTH I and GTH II) were studied using radioimmunoassay. In autumn, ATD treatment reduced pituitary and plasma GTH II levels. In summer, GTH II was consistently nondetectable in plasma. Castration diminished pituitary GTH II content. Treatment with T increased pituitary GTH II content, an effect that was attenuated when T treatment was combined with ATD. All these results are consistent with the presence of an aromatase-dependent positive feedback of T on GTH II. 11KA also had a stimulatory effect on GTH II, although weaker than that of T. Testicular size and spermiation was reduced by ATD in autumn; the latter of these results is likely to be due to the inhibitory effect of ATD on GTH II. Positive effects of ATD on plasma GTH I were found in autumn, indicative of an aromatase-dependent negative feedback in this phase. On the other hand, castration increased plasma and pituitary GTH I levels in summer, indicating that the gonads in this phase exert a predominantely negative control of GTH I. In summer, negative effects of T on GTH I pituitary levels were not suppressed, but were rather enhanced, by the combined treatment with ATD. Furthermore, plasma GTH I levels were lower after treatment with T in combination with ATD than with T or ATD separately. These negative effects of T were not diminished by ATD, so that they are nonaromatase-dependent. Furthermore, since they were actually more pronounced in the presence of ATD it is suggested that there is also a positive aromatase-dependent feedback component in this phase. In addition, 11KA had a negative effect on plasma and pituitary GTH I in castrated previously mature males. Thus, GTH I secretion is controlled by both aromatase-dependent and nonaromatase-dependent feedback effects, of which at least the former may be positive or negative depending on season. In summary, the feedback control of GTH I appears to be more complex than that of GTH II.

HIV-1 subtypes among blood donors from Rio de Janeiro, Brazil

The prevalence of HIV infection in Brazil is one of the highest in the world. In addition, transfusion-transmitted HIV accounts for 2.3% of all AIDS cases in Brazil. The objective of this study was to evaluate genetic diversity and distribution of HIV-1 strains circulating in the blood-donor population. We characterized 43 seropositive blood units collected from volunteer blood donors residing throughout Rio de Janeiro, Brazil. Viral RNA was extracted from plasma, reverse transcribed, and amplified by nested polymerase chain reaction (PCR) using HIV group M degenerate primers. Genetic heterogeneity was evaluated by direct automated cycle sequencing of the following gene fragments: gag p24 (399 bp), env C2V3 (345 bp), and env gp41 (369 bp). Phylogenetic analysis reflected the complexity of the Brazilian HIV epidemic: the majority of specimens, 33 of 43 (76.7%) were subtype B, and 6 of 43 (14%) were subtype F. The remaining 4 samples (9.3%) involved potential mosaic viruses of subtypes B and F or B and D. This survey is the first to document HIV-1 genetic variation in the Brazilian blood-donor population.

Effects of sex steroids on gonadotropin (FSH and LH) regulation in coho salmon (Oncorhynchus kisutch)

The effect of steroid hormone treatment on coho salmon (Oncorhynchus kisutch) was examined. The cDNAs for coho salmon FSH beta and LH beta subunits were cloned and sequenced using reverse transcriptase PCR. Northern blot analysis revealed that a single transcript of 1 kb for each of these subunits was present in the pituitaries of vitellogenic and spermiating coho salmon. RNase protection assays (RPAs) were developed to quantify FSH beta and LH beta subunit transcript levels. For the RPAs, antisense RNA probes and sense RNA standards were prepared from a region of the cDNAs which spanned the signal peptide and a portion of the mature protein. These RPAs were used to examine the effects of exogenous steroids including testosterone, estradiol-17beta (E2) and 17alpha, 20beta-dihydroxy-4-pregnen-3-one (17alpha,20beta-P) in vivo, in coho salmon at three time points during the spring period of gonadal growth when plasma levels of FSH are increasing. Both testosterone and E2 increased steady state mRNA levels of LH beta, whereas E2 decreased steady state mRNA levels of FSH beta in one experiment. Thus, the RPAs were able to detect changes in steady state mRNA levels in response to exogenous steroid treatment. Plasma and pituitary levels of FSH and LH were also measured using RIA. Throughout the experimental series, FSH plasma levels decreased in response to exogenous testosterone and E2 administration, while 17alpha,20beta-P had no effect on FSH plasma levels. Plasma LH levels were not detected throughout the course of the experiment. Pituitary LH increased in response to testosterone and E2, while pituitary FSH levels did not change. 17alpha,20beta-P had no effect on pituitary FSH or LH content during the experiment. Thus, regulation of the gonadotropins in coho salmon occurs at both the transcriptional as well as the translational level. Testosterone and E2 appear to have negative feedback effects on FSH, but positive feedback on LH.

A multicenter trial of ropinirole as adjunct treatment for Parkinson's disease. Ropinirole Study Group

OBJECTIVE

To evaluate the nonergot dopamine agonist ropinirole as an adjunct to L-dopa in a randomized, double-blind trial in PD patients with motor fluctuations.

BACKGROUND

L-dopa in the treatment of PD is associated with motor fluctuations, dyskinesia, and other adverse effects. The use of dopamine agonists in the treatment of PD delays recourse to L-dopa and thus delays the possibility of adverse effect onset.

METHODS

Ropinirole (n = 95) or placebo (n = 54) was added to L-dopa, and L-dopa was then reduced in a planned manner during the 6-month trial.

RESULTS

A significantly greater number of ropinirole patients were able to achieve a 20% or greater reduction in both L-dopa dose and in percent time spent "off" compared with placebo (35.0% versus 13.0%; p = 0.003). The mean daily L-dopa dose was reduced significantly with ropinirole treatment (242 mg versus 51 mg; p < 0.001) as was the percent awake time spent "off" (11.7% versus 5.1%; p = 0.039). There was no difference in the percent of patients who withdrew because of adverse effects (15.8% on ropinirole versus 16.7% on placebo).

CONCLUSIONS

Ropinirole permits a reduction in L-dopa dose with enhanced clinical benefit for PD patients with motor fluctuations.

Effects of gonadectomy and androgen treatments on pituitary and plasma levels of gonadotropins in mature male Atlantic salmon, Salmo salar, parr--positive feedback control of both gonadotropins

The aim of the present study was to clarify the role of feedback control on the (brain)-pituitary-gonadal axis in regulating FSH (gonadotropic hormone, GTH I) and LH (GTH II) in natural maturation in salmonids. In two experiments, 2-yr-old previously mature Atlantic salmon male parr were castrated or sham operated in the spring following their first reproductive season. In one of the experiments, castrated fish were also implanted with silicone elastomer capsules containing testosterone (T) or 11-ketoandrostenedione (11KA). The fish were sampled in July, September, and November (spawning period). Pituitary and plasma LH and FSH levels were measured using RIA and were lower in castrated than in sham-operated fish, indicating positive feedback on both FSH and LH. T, and to a lesser extent 11KA, increased pituitary LH content in castrated fish. The 11KA increased plasma and pituitary FSH levels, whereas T suppressed FSH in July and stimulated it in November. Plasma FSH levels peak earlier than LH, and it is suggested that if one or more feedback effects are involved in controlling the "all-or-nothing response," i.e., whether a fish will mature or not, a feedback effect on FSH is the most likely candidate.

In vitro thyrotropin-releasing activity of corticotropin-releasing hormone-family peptides in coho salmon, Oncorhynchus kisutch

Investigations of hypothalamic regulation of fish thyrotropin (TSH) secretion and subsequent thyroid activity have been impeded by the lack of a reliable assay for TSH. Using a recently developed radioimmunoassay (RIA) for coho salmon TSH we employed an in vitro pituitary cell culture technique to examine regulation of TSH secretion by corticotropin-releasing hormone (CRH) family peptides [ovine CRH (oCRH), carp urotensin I (UI), and frog sauvagine (SV)] as well as thyrotropin-releasing hormone (TRH), salmon growth hormone-releasing hormone (sGHRH), and salmon gonadotropin-releasing hormone (sGnRH). At concentrations of 0.01 to 100 nM, TRH, sGHRH, and sGnRH did not stimulate TSH secretion from coho salmon pituitary cells. However, at these same concentrations, both oCRH and SV caused a significant and concentration-dependent increase in TSH secretion; whereas, UI was highly stimulatory at all concentrations tested. In a related experiment we examined the effect of alpha-helical CRF(9-41) on oCRH-stimulated TSH release by pituitary cells. alpha-Helical CRF(9-41) is an analogue of CRH that has been shown by others to antagonize the adrenocorticotropic hormone (ACTH)-releasing activity of CRH in goldfish. Preincubation of cells with 1 microM alpha-helical CRF(9-41) for 4 h caused a significant suppression of the TSH-releasing activity of oCRH at 1.0 and 10 nM concentrations. The results of these experiments demonstrate the potency of a CRH-like peptide in the hypothalamic regulation of TSH in fish and reveal similarities in the inhibition of the response of both the thyroid and interrenal axis of fish to alpha-helical CRF(9-41).

Salmon thyroid-stimulating hormone: isolation, characterization, and development of a radioimmunoassay

Coho salmon (Oncorhynchus kisutch) thyroid-stimulating hormone (TSH) was isolated by ethanol extraction of pituitary glands from mature coho salmon. Extraction was followed by gel-filtration chromatography on Sephadex G-100 superfine, anion-exchange chromatography on a Whatman DE-52 column, and finally by reverse-phase high-performance liquid chromatography. Fractions were monitored for TSH content by a homologous in vivo bioassay and by immunoblots using anti-human TSH beta-subunit antisera. In vivo treatment of coho salmon parr with coho salmon TSH caused a dose-dependent increase in plasma thyroxine level similar to that induced by bovine TSH. The N-terminal sequence (25 residues) of the salmon TSH beta subunit has 56% sequence identity to that of human TSH beta subunit and is identical to the deduced amino acid sequence of trout TSH beta subunit. The N-terminal sequence (25 residues) of the salmon TSH alpha subunit is identical to gonadotropin alpha-II subunit. Molecular sizes of the alpha and beta subunits are 18,000 and 24,000 daltons, respectively, as estimated by SDS-PAGE. Antiserum generated against salmon TSH, which was preadsorbed with alpha subunit using an alpha-subunit affinity column, detected only salmon TSH beta subunit by immunoblot and specifically stained thyrotropin-producing cells of the pituitary gland. A homologous radioimmunoassay (RIA) was developed using purified salmon TSH standard, iodinated TSH beta subunit, and antiserum generated against salmon TSH. Cross-reactivities of GTH I, GTH II, GTH I beta and GTH II beta subunits, alpha subunit, growth hormone, prolactin, and somatolactin were less than 1%. Displacement curves for serial dilutions of plasma and pituitary extracts of various salmonid species, as well as coho salmon pituitary cell culture medium, were parallel to the coho salmon TSH standards. In contrast, plasma of hypophysectomized juvenile coho salmon and pituitary extracts of Pacific tomcod (Microgadus proximus) did not displace bound radiolabeled salmon TSH. Finally, in vivo injection of juvenile coho salmon with triiodothyronine decreased plasma TSH levels, whereas the goitrogen, methimazole, increased plasma TSH levels. Injection of gonadotropin-releasing hormone agonist did not alter plasma TSH. These data suggest that the RIA is specific for TSH and confirm a negative-feedback relationship between the thyroid hormones and TSH.

RAG-1 and RAG-2-dependent assembly of functional complexes with V(D)J recombination substrates in solution

V(D)J recombination is initiated by RAG-1 and RAG-2, which introduce double-strand DNA breaks at recombination signal sequences (RSSs) of antigen receptor gene segments to produce signal ends, terminating in blunt, double-strand breaks, and coding ends, terminating in DNA hairpins. While the formation of RAG-RSS complexes has been documented, observations regarding the individual contributions of RAG-1 and RAG-2 to RSS recognition are in conflict. Here we describe an assay for formation and maintenance of functional RAG-RSS complexes in the course of the DNA cleavage reaction. Under conditions of in vitro cleavage, the RAG proteins sequester intact substrate DNA in a stable complex which is formed prior to strand scission. The cleavage reaction subsequently proceeds through nicking and hairpin formation without dissociation of substrate. Notably, the presence of both RAG-1 and RAG-2 is essential for formation of stable, functional complexes with substrate DNA under conditions of the sequestration assay. Two classes of substrate mutation are distinguished by their effects on RAG-mediated DNA cleavage in vitro. A mutation of the first class, residing within the RSS nonamer and associated with coordinate impairment of nicking and hairpin formation, greatly reduces the stability of RAG association with intact substrate DNA. In contrast, a mutation of the second class, lying within the RSS heptamer and associated with selective abolition of hairpin formation, has little or no effect on the half-life of the RAG-substrate complex.

Purification of gonadotropin II from a teleost fish, the hybrid striped bass, and development of a specific enzyme-linked immunosorbent assay

A highly purified gonadotropin II (GtH II), referred to as striped bass GtH II (stbGtH II), and its alpha and beta subunits were prepared from pituitaries of sexually mature hybrid striped bass. Pituitary glycoproteins were extracted with ethanol and intact stbGtH II purified by gel-filtration chromatography on Sephadex G-100, ion-exchange chromatography (IEC) on DE-52, and fast-performance liquid chromatography (FPLC) on Superdex 75. The presence of GtHs during the purification procedure was monitored by characteristic elution on reversed-phase high-performance liquid chromatography (rpHPLC) and in vitro steroidogenic activity. The stbGtH II alpha and beta subunits were purified from the pituitary ethanol extract by gel-filtration, IEC, and rpHPLC, and their identities assessed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), rpHPLC, and N-terminal amino acid sequencing. Molecular weights of intact stbGtH II and its alpha and beta subunits, determined by SDS-PAGE, were 34.5, 14.8, and 20.4 kDa, respectively. The stbGtH II beta subunit was used to produce specific antibodies, and a competitive enzyme-linked immunosorbent assay was developed using intact stbGtH II for the standard curve. The sensitivity of the assay was 156 pg/ml (15.6 pg/well) and the intra- and interassay coefficients of variation (at 50% binding) were 7.7% (n = 16) and 8.7% (n = 10), respectively. Physiological validation of the assay was performed by measuring changes of plasma GtH II levels in mature striped bass females, after injection of GnRHa ([d-Ala6,Pro9-NEt]-mGnRH, 100 microg/kg BW). A maximum surge of GtH II in plasma was observed at 12 hr postinjection (22.5 +/- 3. 01 ng/ml), whereas GtH II levels in control fish (around 4 ng/ml) remained unchanged. Displacement curves obtained with serial dilutions of plasma and pituitaries from a number of perciform species were parallel to the standard curve, indicating that this assay can be used for GtH II measurements in a variety of fish species.

Modulation of testicular androgen production in adolescent African catfish (Clarias gariepinus)

At 6 months of age the first spermatozoa appear in the testes of the African catfish considered to be adolescent, since the development to adulthood (12 months of age) is accompanied by further morphological and functional differentiation of Leydig cells. There are increasing plasma levels of 11-ketotestosterone (11-KT) and an increasing responsiveness to luteinizing hormone (LH) of testicular androgen secretion in vitro. Whether treatment of adolescent males with key hormones of the brain-pituitary-gonad axis [gonadotropin-releasing hormone (GnRH), LH, and 11-KT] affects the testicular steroidogenic response to a challenge with LH in vitro 7 days later has been investigated. Injection of GnRH (2.5 microg chicken GnRH-II per kilogram of body weight), LH (25 microg/kg), or a high dose of 11-KT (50 microg/kg) down-regulated basal and LH-stimulated testicular androgen secretion to a minimum of 35% of control values. Treatment with LH was, moreover, associated with changes in the ultrastructure of Leydig cell mitochondria which were either swollen and had a less electron-dense matrix or showed an elongated shape. Conversely, a moderate dose of 11-KT (20 microg/kg) enhanced LH-stimulated, but not basal, androgen secretion in vitro to a maximum of 190% of control values. In view of the generally low LH plasma levels and of the steadily increasing 11-KT plasma levels during puberty, 11-KT may be involved in the up-regulation of the testicular steroidogenic capacity observed during development to full maturity.

Effects of gonadectomy on plasma gonadotropins I and II in coho salmon, Oncorhynchus kisutch

Studies of both salmon and trout have indicated that the levels of gonadotropins, GTH I and GTH II, in the pituitary and peripheral circulation vary during the reproductive cycle. To evaluate the possible feedback relationship between the gonads and pituitary GTH secretion, we studied the effects of bilateral gonadectomy on plasma levels of GTH I and GTH II in coho salmon, Oncorhynchus kisutch. During late spermatogenesis in males and late vitellogenesis in females, plasma GTH I levels increased significantly after gonadectomy, approximately 6- and 5-fold over presurgery levels at 3 and 14 days after surgery, respectively, and then declined to near presurgery levels by Day 17. No change in GTH I levels occurred in sham-operated fish. In all groups, GTH II levels were nondetectable and did not change significantly up to 17 days postsurgery. In males gonadectomized during spermiation, plasma GTH I levels increased significantly, approximately 10-fold over presurgery levels by 7 days postsurgery, and remained elevated thereafter. In contrast to the males in late spermatogenesis, the spermiating fish had detectable levels of GTH II (2-3 ng/ml), and significant elevations in plasma GTH II levels (approximately 60-fold) were observed 7 days after gonadectomy. These experiments demonstrate that the gonads exert negative feedback effects on secretion of both GTH I and GTH II, but the effect varies seasonally and the nature of the specific factor(s) from the gonads that inhibits and/or stimulates GTH production and secretion remains to be clarified.

Stimulation of brook trout ovarian steroidogenesis by gonadotropins I and II is mediated by the cyclic adenosine 3',5'-monophosphate/protein kinase A pathway

In teleosts, ovarian steroidogenesis is under the control of two gonadotropic hormones, GTH I and GTH II, that are structurally and functionally homologous to FSH and LH. The intracellular mechanisms by which GTH I and GTH II stimulate steroidogenesis in the teleost ovary are not well understood. The purpose of this study was to investigate the involvement of the cAMP/protein kinase A (PKA) and protein kinase C (PKC)/Ca2+ signaling pathways in the steroidogenic actions of GTH I and GTH II in the ovary of the brook trout (Salvelinus fontinalis). The cAMP/PKA pathway mediated the actions of GTH I before germinal vesicle breakdown (preGVBD) and GTH II after GVBD and before ovulation (preOV). Experimental increases in intracellular cAMP concentration mimicked the steroidogenic effects of GTH I and GTH II, and an antagonistic analog of cAMP partially blocked them. In addition, GTH I and GTH II stimulated the production of cAMP in preGVBD and preOV follicles, respectively. Activation of the PKC/Ca2+ pathway by a phorbol ester or a Ca2+ ionophore blocked the GTH I- and GTH II-induced steroid production, whereas inhibition of PKC by specific inhibitors potentiated the effects of GTH I. These results suggest that the cAMP/PKA signaling pathway mediates the stimulatory effects of GTH I and GTH II on steroidogenesis, and they also suggest the additional involvement of the PKC/Ca2+ signaling pathway in modulating the actions of gonadotropins in brook trout ovarian follicles.

Differential serological diagnosis of HTLV-I and HTLV-II infection by external membrane protein peptide-based enzyme immunoassays

BACKGROUND

HTLV antibody screening assays detect both antibodies to the etiological agent of adult T-cell leukemia and tropical spastic paraparesis HTLV-I and to the less pathogenic HTLV-II. It is critical to make a differential diagnosis of the two viruses.

OBJECTIVES

To design and evaluate synthetic core and envelope-derived peptide enzyme immunoassays (EIA) for serological differential diagnosis.

STUDY DESIGN

Peptide EIAs were evaluated with a panel of 202 plasma samples comprised of HTLV antibody positive, serologically classified as confirmed, indeterminate, or non confirmed, characterized as HTLV-I, HTLV-II or neither by genomic amplification. The peptide EIA with the best performance was further used to differentiate between HTLV-I and HTLV-II antibodies in 807 samples from 18 countries in four continents and to provide ratios between the two infections.

RESULTS

The gp46 peptide EIA correctly identified 96.5% of HTLV-I and 98.6% of HTLV-II antibody-confirmed samples. HTLV-I was found exclusively in Japan and Caribbean countries; almost exclusively in Africa. HTLV-II represented 10-25% of samples from Canada, Chile and Venezuela and was predominant in the US.

CONCLUSIONS

Differential diagnosis between HTLV-I and HTLV-II can be reliably performed using specific peptides from the gp46 envelope protein of each virus.

Ovarian receptors for insulin and insulin-like growth factor I (IGF-I) and effects of IGF-I on steroid production by isolated follicular layers of the preovulatory coho salmon ovarian follicle

In this study, receptors for insulin and insulin-like growth factor I (IGF-I) in isolated theca-interstitial layers and granulosa cells of the coho salmon preovulatory ovary were characterized, and the effects of IGF-I on ovarian steroidogenesis were examined. Specific receptors for insulin and IGF-I were found in granulosa and theca-interstitial layers. In both follicular layers, IGF-I receptors were greater in number and higher in affinity than insulin receptors. The effects of IGF-I on in vitro production of testosterone (T) and 17 alpha-hydroxyprogesterone (17OH-P) by theca-interstitial layers and of 17 beta-estradiol (E2) and 17 alpha, 20 beta-dihydroxy-4-pregnen-3-one (17,20 beta-P) by granulosa cell layers were evaluated during the preovulatory period. Both human and salmon recombinant IGF-I inhibited the basal and GTH II-stimulated T and 17OH-P production by theca-interstitial layers throughout the preovulatory period. In contrast, IGF-I stimulated the production of both E2 and 17,20 beta-P by granulosa cell layers prior to germinal vesicle breakdown (GVBD) but only stimulated the production of 17,20 beta-P by granulosa cell layers after GVBD. The inhibitory effects of IGF-I on steroid production by the theca-interstitial layer and the opposite stimulatory effects on steroid production by the granulosa cell layer, coupled by the presence of specific IGF-I receptors in both follicular layers, suggest that IGF-I may play a role in the regulation of steroidogenesis in the preovulatory coho salmon ovary.