Production of transgenic live-bearing fish and crustaceans with replication-defective pantropic retroviral vectors

Transgenic fish have been routinely produced by microinjecting or electroporating foreign DNA into one-cell stage embryos or unfertilized eggs. While both techniques are effective in producing transgenic fish species from which unfertilized or newly fertilized eggs can be easily obtained, these techniques are not applicable to live-bearing fish and many crustacean species where unfertilized or newly fertilized eggs are not readily available. In this paper, we describe a new method of introducing foreign DNA into the live-bearing fish, Poeciliposis lucida, and crayfish, Procambarus clarkii, by directly transforming the immature ovary or testis of these animals with replication-defective pantropic retroviral vectors carrying a reporter gene (neo(R)). A significant fraction of the progeny derived from these treated animals contains the neo(R) reporter gene, determined by a PCR-based assay. The PCR-positive individuals were crossed with nontransgenic individuals, and about 50% of the resulting progeny carried the transgene, suggesting that the F(1) animals are germline transgenic. Integration of the transgenes was confirmed by detecting the junction fragments of the genomic DNA associated with transgene constructs. The expression of reporter genes was detected by reverse transcription (RT) PCR assay. These results showed that foreign genes could be reproducibly transferred into live-bearing fish and crustaceans by directly transforming the immature gonads with replication-defective pantropic retroviral vectors.

Influence of environmental salinity on messenger RNA levels of growth hormone, prolactin, and somatolactin in pituitary of the channel catfish (Ictalurus punctatus)

Pituitary growth hormone (GH), prolactin (PRL), and somatolactin (SL) messenger RNA levels in channel catfish (Ictalurus punctatus) were examined under various environmental and physiological conditions. Catfish were sampled following salinity challenge, during the winter (December) and spring or summer (April or July), and at different sizes (15-18 g, 620-664 g, and 956-1134 g). When catfish (956-1134 g) were transferred from freshwater to saline water containing 8 ppt NaCl, their plasma [Na(+)] increased significantly above values in the freshwater control group until they were transferred back to freshwater. Pituitary GH mRNA levels were low for the first 24 hours following transfer to saline water, but thereafter were significantly elevated above control values until the fish were transferred back to freshwater. Pituitary GH mRNA levels were highest in July and lowest in December. Growth hormone mRNA levels were also elevated in the size groups 15-18 g and 956-1134 g in July when compared with December values. Pituitary PRL mRNA levels increased for the first 24 hours following transfer to saline water (956-1134 g), but thereafter were significantly lower than control values until the fish were transferred back to freshwater. Pituitary PRL mRNA levels were highest in April and July and lowest in December, and were also elevated in the size groups 620-664 g and 956-1134 g. Pituitary SL mRNA levels were unaffected in catfish transferred to saline water; however, levels were significantly elevated in catfish of the 956-1134-g size group sampled in April when compared with December. These results suggest the involvement of GH in adaptation to brackish water and of PRL in adaptation to freshwater in the catfish, and seasonal and size-related differences in pituitary GH, PRL, and SL mRNA levels.

The large subunit of replication factor C promotes cell survival after DNA damage in an LxCxE motif- and Rb-dependent manner

Retinoblastoma (Rb) protein promotes cell survival after DNA damage. We show here that the LxCxE binding site in Rb mediates both cell survival and cell-cycle arrest after DNA damage. Replication factor C (RF-C) complex plays an important role in DNA replication. We describe a novel function of the large subunit of RF-C in promoting cell survival after DNA damage. RF-Cp145 contains an LxCxE motif, and mutation of this motif abolishes the protective effect of RF-Cp145. The inability of wild-type RF-Cp145 to promote cell survival in Rb-null cells is rescued by Rb but not by Rb mutants defective in binding LxCxE proteins. RF-C thus enhances cell survival after DNA damage in an Rb-dependent manner.

The hexapeptide KP-102 (D-ala-D-beta-Nal-ala-trp-D-phe-lys-NH(2)) stimulates growth hormone release in a cichlid fish (Ooreochromis mossambicus)

Abstract Studies in mammals have shown that synthetic Met-enkephalin derivatives, called growth hormone-releasing peptides (GHRPs), stimulate growth hormone (GH) release. The present study was conducted to determine whether the GHRP, KP-102, specifically stimulates GH release in a teleost. Tilapia (Oreochromis mossambicus) were given a single intraperitoneal injection of KP-102 (D-Ala-D-beta;-Nal-Ala-Trp-D-Phe-Lys-NH(2)) or bovine GHRH(1-29)-amide or vehicle and blood was sampled at 1, 6 and 12 h after injection. KP-102 was administered at two doses of 1 ng/g and 10 ng/g body weight, whereas GHRH (positive control) was administered at a single dose of 10 ng/g body weight. Plasma levels of tilapia GH and prolactins (tPRL(177) and tPRL(188)) were determined by radioimmunoassay. As expected, GHRH injection significantly (P<0.001) elevated plasma GH levels (ng/ml) in tilapia at 6 h post-injection. KP-102 also significantly elevated GH levels (at the low dose) at 6 (P<0.05) and 12 (P<0.01) hours post-injection. There were no significant effects on plasma PRL(s) levels, although mean levels of both PRLs were elevated at 6 h post-injection. These results show for the first time that GHRPs stimulate GH release in teleosts and suggest that the GHRP receptor and possibly a "Ghrelin-like" ligand are also present in lower vertebrates.

Identifying attitudinal barriers to family management of cancer pain in palliative care in Taiwan

The purpose of this study was threefold: (1) to examine attitudes held by Taiwanese family caregivers of hospice inpatients with cancer that serve as barriers to cancer pain management; (2) to determine the relationship of attitudinal barriers to family caregiver hesitancy to report pain and to administer analgesics; and (3) to determine the relationship of attitudinal barriers to the adequacy of analgesics used by the patient. A total of 80 pairs of palliative care inpatients and their primary family caregivers participated in this study. Family caregivers completed the Barriers Questionnaire-Taiwan (BQT) form and a demographic questionnaire. The instruments completed by patients consisted of the Brief Pain Inventory-Chinese version and a demographic questionnaire. The data revealed that Taiwanese family caregivers of palliative care patients with advanced cancer had concerns about reporting pain and administering analgesics, particularly as they related to disease progression, side-effects and p.r.n. analgesics. Older and less-educated family caregivers scored significantly higher on the BQT than did their younger, more educated counterparts. Family caregivers' concerns measured by the BQT were related to family caregivers' reluctance to administer analgesics to their patients. Implications for a broader understanding of analgesics in the advancement of pain management in palliative care in Taiwan are discussed.

A model to select chemotherapy regimens for phase III trials for extensive-stage small-cell lung cancer

BACKGROUND

Many more phase II studies have favorable outcomes than the subsequent phase III trials. We used historical data from phase II and phase III studies for patients with extensive-stage small-cell lung cancer (SCLC) to generate a statistical model to provide assistance in selecting chemotherapy regimens from phase II studies for subsequent use in phase III randomized studies.

METHODS

Information from 21 phase III trials for patients with extensive-stage SCLC initiated during the period from 1972 through 1990 was reviewed to identify those that were preceded by phase II studies of the same regimen. We used data from all the trial pairs to develop a statistical model in which the number of patients, the median survival of patients, and the number of deaths observed in the phase II trial are used to estimate the statistical power of the subsequent phase III trial. All statistical tests were two-sided.

RESULTS

Nine phase II studies were identified that preceded phase III trials of the same regimen. The regimens from two phase II studies with the greatest expected power in the phase III trial (0. 62 and 0.58) both demonstrated significantly prolonged survival when compared with standard treatment in subsequent phase III trials (P<. 001 and P =.002, respectively). The regimens from six of the other phase II studies, for which the median power expected in the phase III trial was 0.28 (range, 0.19-0.52), showed no difference when compared with standard treatment in a phase III trial.

CONCLUSIONS

Phase II studies for particular regimens that have an expected power of greater than 0.55 provide a reasonable basis for proceeding with a phase III trial.

Cervical cancer outcomes analysis: impact of age, race, and comorbid illness on hospitalizations for invasive carcinoma of the cervix

OBJECTIVE

The aim of this study was to evaluate the association of age, race, and comorbid illness with procedures and complications in hospitalized patients with invasive carcinoma of the cervix in a statewide population-based database over a 3-year period.

METHODS

Hospitalizations were classified into homogeneous subgroups based on a diagnosis of invasive cervical cancer. Cancer-related complications and comorbid diseases were evaluated. chi(2) and t tests determined differences in means or proportions. Linear regression techniques were applied to build models for hospitalization charges and lengths of stay (LOS).

RESULTS

There were 1009 admissions. The mean age was 49.5, with a median age of 46 (21-100, SD 15.4). Of the total, 606/1009 (60%) were white, 354/1009 (35%) were African-American (AA), and 5% were "other" races. AAs were more likely to have Medicaid or be uninsured (44% vs 23%, P = 0. 001) and were more likely to be admitted for an emergency (unadjusted odds ratio (OR) = 1.6; 1.2-2.2), to have a comorbid illness (P = 0.001), to be admitted for a cancer-related complication (P = 0.036), to be admitted for a transfusion (P = 0. 01), and to be admitted for radiation therapy rather than surgery (P = 0.001). The following were associated with LOS and higher hospital costs: emergency admissions for complications of cancer, comorbid illness, and older age.

CONCLUSIONS

Racial differences exist in patterns of admission, type of therapy, and severity of illness; however, there were no differences in charges or LOS for similar procedures. The large percentage of African-Americans uninsured or insured by government-supported programs indicates the potential impact of public policy on the care of these patients. Socioeconomic status rather than phenotypic appearance may be a more important determinant of outcome.

Establishment of irreversible growth arrest in myogenic differentiation requires the RB LXCXE-binding function

The crystal structure of the A-B domain of RB has defined the binding pocket for the LXCXE peptide motif. Using the crystal structure as a guide, we have inactivated the LXCXE-binding pocket by replacing N757 with Phe [to obtain RB(N757F)]. RB(N757F) does not bind to viral oncoproteins but retains the ability to bind and inhibit E2F. RB(N757F) is less effective than the wild-type RB [RB(WT)] in repressing E2F-regulated transcription, and its repression activity is not affected by trichostatin A, an inhibitor of histone deacetylases. However, RB(N757F) is as effective as RB(WT) in suppressing cell growth. Interestingly, RB(N757F) cannot establish an irreversible growth arrest in differentiated myocytes. Differentiated myocytes with RB(WT) become refractory to serum. By contrast, differentiated myocytes with RB(N757F) undergo DNA synthesis and phosphorylate RB(N757F) in response to serum, despite a high level of p21Cip1 expression. Mutation of the phosphorylation sites in RB(N757F) rescued its defect and allowed myocytes to permanently withdraw from the cell cycle. These results demonstrate that it is possible to inactivate the LXCXE-binding pocket without compromising the overall integrity of RB. Moreover, the LXCXE-binding pocket is dispensable for the intrinsic growth suppression function of RB. However, the LXCXE-binding function is essential for RB to establish the serum-refractory state in differentiated myocytes.

Expression of breast cancer resistance protein in blast cells from patients with acute leukemia

Breast cancer resistance protein (BCRP) is a novel member of the adenosine triphosphate-binding cassette superfamily of transport proteins. Transfection and enforced expression of BCRP in drug-sensitive cells confer resistance to mitoxantrone, doxorubicin, daunorubicin, and topotecan. We studied blast cells from 21 acute leukemia patients (20 acute myeloid leukemia, 1 acute lymphocytic leukemia) for the expression of BCRP mRNA using a quantitative reverse-transcription polymerase chain reaction assay. BCRP mRNA expression varied more than 1000-fold among the samples tested, with low or barely detectable expression in half of the samples. Seven samples (33%) had relatively high expression of BCRP mRNA. High expression of BCRP did not correlate strongly with high expression of P-glycoprotein, suggesting that BCRP may cause resistance to certain antileukemic drugs in P-glycoprotein-negative cases. High expression of BCRP mRNA is sufficiently frequent in AML to warrant more extensive investigations to determine the relation of disease subtype and treatment outcome to BCRP expression and function.

Differential expression of two CYP1A genes in rainbow trout (Oncorhynchys mykiss)

Differential expression of two rainbow trout CYP1A genes was measured in vivo and in vitro in response to treatment with the model CYP1A inducers beta-naphthoflavone (BNF), 3-methylcholanthrene (3-MC), isosafrole (ISF), and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD, only in vitro). Originally described by Berndtson and Chen (Arch. Biochem. Biophys. 310, 187-195, 1994) as CYP1A1 and CYP1A2, these genes were renamed CYP1A3 and CYP1A1, respectively, by the P450 nomenclature committee. A significant, differential, inducer-dependent induction of the two CYP1A mRNAs, as measured by RNase protection assay, was observed in vivo. CYP1A3 and CYP1A1 mRNA levels in liver were significantly induced 50- and 18-fold, respectively, following ip injection with BNF. Conversely, CYP1A3 and CYP1A1 mRNA levels were significantly induced 5- and 66-fold, respectively, following ip injection with 3-MC. Isosafrole had no significant effect on in vivo induction of CYP1A mRNA levels. In primary cultures of hepatocytes, BNF, 3-MC, ISF, as well as TCDD all significantly induced CYP1A3 and CYP1A1 mRNA levels compared to controls. The differential induction of the two CYP1A genes was not as evident in vitro as in vivo. In addition, reanalysis and sequence comparison of the these two trout CYP1A genes with the first trout CYP1A cDNA described by Heilmann et al. (DNA 7, 379-387, 1988) indicate that the Heilmann cDNA is a hybrid of the two trout genes. The 5' portion of the cDNA sequence (212 bp) was determined by sequencing of a genomic clone and is 100% identical to the trout CYP1A3 gene. The majority of the cDNA sequence (2377 bp), however, was sequenced from a partial cDNA clone and is 99.2% identical to trout CYP1A1. Although the nomenclature of these two trout CYP1A genes is undergoing revision, these results demonstrate a differential, inducer-dependent response to model mammalian CYP1A inducers.

Febrile core temperature is essential for optimal host defense in bacterial peritonitis

Fever, a nonspecific acute-phase response, has been associated with improved survival and shortened disease duration in infections, but the mechanisms of these beneficial responses are poorly understood. We previously reported that increasing core temperature of bacterial endotoxin (LPS)-challenged mice to the normal febrile range modified expression of tumor necrosis factor alpha (TNF-alpha), interleukin 1beta (IL-1beta), and IL-6, three cytokines critical to mounting an initial defense against microbial pathogens, but survival was not improved in the warmer animals. We speculated that our inability to show a survival benefit of optimized cytokine expression in the warmer animals reflected our use of LPS, a nonreplicating agonist, rather than an infection with viable pathogens. The objective of this study was to determine if increasing murine core temperature altered cytokine expression and improved survival in an experimental bacterial peritonitis model. We showed that housing mice at 35.5 degrees C rather than 23 degrees C increased core temperature from 36.5 to 37.5 degrees C to 39.2 to 39.7 degrees C, suppressed plasma TNF-alpha expression for the initial 48 h, delayed gamma interferon expression, improved survival, and reduced the bacterial load in mice infected with Klebsiella pneumoniae peritonitis. We showed that the reduced bacterial load was not caused by a direct effect on bacterial proliferation and probably reflected enhanced host defense. These data suggest that the increase in core temperature that occurs during bacterial infections is essential for optimal antimicrobial host defense.

Quantitation of IGF-I, IGF-II, and multiple insulin receptor family member messenger RNAs during embryonic development in rainbow trout

The IGF system has been shown to be important for normal embryonic growth in mice. Characterization of the IGF system in lower vertebrates is still in progress. To gain a greater understanding of the IGF system during embryonic development in teleosts, a competitive reverse transcription-polymerase chain reaction (RT-PCR) assay was developed and used to quantitate the levels of IGF-I and IGF-II mRNAs from rainbow trout embryos isolated from a staged series. The absolute number of molecules of IGF-I mRNA/microg total RNA was significantly lower than the absolute number of molecules of IGF-II mRNA/microg total RNA both during early and late embryonic development. The recent identification of multiple IGF type I receptor (rtIGFR) and insulin receptor (rtIR) cDNAs in rainbow trout has provided us with a tool to investigate the expression of these mRNAs. A relative quantitative RT-PCR assay was used to determine the steady state levels of two forms of rtIGFR and three forms of rtIR mRNAs in rainbow trout embryos. The relative levels of rtIGFR mRNAs were greater in embryos compared to adult tissues while the relative levels of rtIR mRNAs were generally lower. In a RT-PCR based assay, a differential ability to detect rtIGFR and rtIR mRNAs was shown, suggesting developmental regulation of polyadenylation. Our results suggest that IGF-II mRNA is the predominant IGF expressed in rainbow trout embryos. Our characterization of IGF ligand and receptor mRNA levels in rainbow trout embryos suggests that a functional IGF system exists during embryonic development in teleosts.

Predator Avoidance of Transgenic Channel Catfish Containing Salmonid Growth Hormone Genes

Transgenic channel catfish (Ictalurus punctatus) containing salmonid growth hormone genes can grow 33% faster than normal channel catfish under aquaculture conditions. However, before transgenic catfish are released and utilized by the private sector, their genetic impact on the natural environment must be examined. Predator avoidance is one of the major fitness traits determining potential environmental risk. To determine the predator avoidance ability and growth performance of transgenic catfish in a natural habitat, various densities of transgenic and nontransgenic channel catfish were communally stocked in 0.04-ha earthen ponds without supplemental feeding. Largemouth bass (Micropterus salmoides) and green sunfish (Lepomis cyanellus) were stocked as predators. Nontransgenic fry had better predator avoidance than transgenic channel catfish when data were pooled (p <.01). When data were not pooled, nontransgenic catfish had better predator avoidance in six trials and transgenic individuals had better predator avoidance in four trials. There was no difference in predator avoidance in three trials. Overall predator avoidance was also better for nontransgenic individuals (p <.01) when the fish were evaluated as 3.5-g fingerlings, more clearly than as fry, as transgenic individuals were more vulnerable in 3 of 4 trials at this life stage. There was no significant difference in growth performance between transgenic and nontransgenic channel catfish in ponds without supplemental feeding. These findings indicate that transgenic channel catfish could be used for commercial aquaculture without affecting the natural environment. Although transgenic channel catfish may be released to nature by accident, any ecological effect would be unlikely because the increased susceptibility of transgenic channel catfish to predators would most likely decrease or eliminate the transgenic genotype.

Application of rapid random stimulation (RRS) to visual evoked potentials in children

The present study was performed to examine the effects of regular (1 Hz) and modified rapid random stimulation (RRS) (6 and 12 Hz) on visual evoked potentials (VEPs), by simultaneously recording negative waves around 100 ms, wave IV-latency, positive waves around 60 ms, wave III-latency, and amplitudes calculated from peak to peak, without causing impairment of visual acuity, in 44 patients aged 5-17 years. The wave IV-latencies of VEPs obtained by 6 and 12 Hz RRS were easily determined, and the latencies were not significantly changed compared to those obtained by previous 1 Hz regular stimulation. On the other hand, the amplitudes decreased in a frequency-dependent manner (1 < 6 < 12 Hz). These results were found to be similar in both preschool and school children. The examination time of VEPs determined by RRS is one-tenth shorter than that of 1 Hz regular stimulation. Thus, this method has the benefit of shortening the examination time, which decreases fatigue and inattention of the subjects, suggesting that modified RRS is a practically useful method for children.

TP53 mutation and haplotype analysis of two large African American families

Two large apparently unrelated African American families with a high incidence of breast cancer and other tumors characteristic of Li-Fraumeni breast sarcoma cancer family syndrome were studied. Mutation screening revealed that in both families the affected members carried a germline mutation of the TP53 gene at codon 133 (ATG--> ACG, M133T). In order to determine whether an ancestral haplotype was shared by these two families, polymorphic markers within and flanking the TP53 gene were studied. Haplotype analysis using five markers revealed an identical haplotype shared by the two families. Loss of heterozygosity at the TP53 locus in the probands' tumor tissues from each family was observed; in each case, the retained allele carried the common haplotype. The frequency of this haplotype in the general African American population is <0.003. This unique haplotype, combined with the rare TP53 mutation, suggests that these African American families share a common ancestry. This finding suggests that other African Americans may be carriers of this mutation and thus may be at risk of early-onset breast cancer or other cancers characteristic of the Li-Fraumeni breast sarcoma cancer family syndrome. The finding of recurring mutations in African Americans may facilitate carrier screening and identification in this population.

Evolution of a cytokine using DNA family shuffling

DNA shuffling of a family of over 20 human interferon-alpha (Hu-IFN-alpha) genes was used to derive variants with increased antiviral and antiproliferation activities in murine cells. A clone with 135,000-fold improved specific activity over Hu-IFN-alpha2a was obtained in the first cycle of shuffling. After a second cycle of selective shuffling, the most active clone was improved 285,000-fold relative to Hu-IFN-alpha2a and 185-fold relative to Hu-IFN-alpha1. Remarkably, the three most active clones were more active than the native murine IFN-alphas. These chimeras are derived from up to five parental genes but contained no random point mutations. These results demonstrate that diverse cytokine gene families can be used as starting material to rapidly evolve cytokines that are more active, or have superior selectivity profiles, than native cytokine genes.

Characterization of teleost insulin receptor family members

Insulin from mammals and fish has been used to determine insulin-binding affinities and receptor numbers with remarkable similarities between these two vertebrates, suggesting functional conservation. Yet, the nature and structure of teleost insulin receptors are not known. Therefore, the cloning and mRNA characterization of rainbow trout insulin receptors were undertaken. Three insulin receptor cDNAs were isolated by screening a cDNA library, confirmed as separate genes by genomic Southern hybridization, and designated as rainbow trout insulin receptor a (rtIR a), rainbow trout insulin receptor b (rtIR b), and rainbow trout insulin receptor c (rtIR c). A high degree of amino acid identity was observed between rainbow trout insulin receptors (rtIRs) and their human homolog, confirming the structural similarities between mammalian and fish insulin receptors. Reverse transcription-polymerase chain reaction from total RNA using either oligo(dT) or random hexamer primers resulted in a diminished ability to detect rtIR a and rtIR b mRNA when oligo(dT) was used, suggesting developmental and tissue-specific polyadenylation. The highest steady-state levels of rtIR mRNAs were consistently detected in juvenile and adult pyloric caeca (which also contained adipose and pancreatic tissue), while the lowest levels were consistently found in muscle. A high level of rtIR b and rtIR c mRNA was also found in ovary, while a high level of rtIR a was found in adult brain. Significant differences were also found between steady-state rtIR mRNA levels in corresponding juvenile and adult tissues. These results suggest a complex expression pattern of insulin receptor mRNAs in partial tetraploid fish.

Characterization of teleost insulin receptor family members. II. Developmental expression of insulin-like growth factor type I receptor messenger RNAs in rainbow trout

The insulin-like growth factor (IGF) system in teleosts consists of two ligands, IGF-I and IGF-II, multiple binding proteins, and high-affinity transmembrane receptors. There exists a large gap in our knowledge of the structure and expression of receptors mediating the biological effects of the IGFs in teleosts. For example, nucleotide sequence data other than those from the kinase domain, evidence of multiple genes, mRNA expression pattern and polyadenylation status in multiple tissues at different developmental stages, and quantitation of mRNA levels in multiple tissues are not known for any teleost. In the study described here, two rainbow trout IGF type I receptor cDNAs (rtIGFR Ia and rtIGFR Ib) were isolated by a 5' rapid amplification of cDNA ends method and confirmed as separate genes by genomic Southern blot hybridization. The predicted amino acid sequences are 85% identical to each other in the tyrosine kinase domain. Both cDNAs are more homologous to mammalian IGF type I receptors than to insulin receptors. Reverse transcription-polymerase chain reaction from total RNA using either oligo(dT) or random hexamers as primers resulted in a diminished ability to detect IGF receptor mRNAs when oligo(dT) was used, suggesting developmental and tissue-specific polyadenylation. The highest steady-state mRNA levels of rtIGFR Ia were found in juvenile gill and adult heart, while the highest levels of rtIGFR Ib were found in adult pyloric caeca, which also contained diffuse pancreatic and adipose tissue. The lowest steady-state mRNA levels of both rtIGFR Ia and rtIGFR Ib were found in juvenile heart, liver, muscle, and spleen, and adult liver. Significant differences in steady-state mRNA levels were also found between juveniles and adults. These results suggest a complex expression pattern of IGF type I receptor mRNAs in partial tetraploid fish.

Regression of endometrial explants in a rat model of endometriosis treated with the immune modulators loxoribine and levamisole

OBJECTIVE

To investigate the effects of the immune modulators levamisole and loxoribine in a rat model of endometriosis.

DESIGN

Prospective, placebo-controlled study.

SETTING

Hospital-based research facility.

ANIMAL(S)

Nineteen rats with experimentally induced endometriosis.

INTERVENTION(S)

Rats were treated with three weekly intraperitoneal injections of levamisole (2 mg per rat; n = 6), loxoribine (1 mg per rat; n = 6), or saline (control; n = 7) and killed 8 weeks after treatment.

MAIN OUTCOME MEASURE(S)

Histologic and immunohistochemical analysis of endometriotic explants.

RESULT(S)

The loxoribine-treated group showed marked regression of both epithelial and stromal components. Epithelial regression was noted in the control group, but the epithelium was strikingly preserved in the levamisole group. There were significantly greater numbers of dendritic cells in the explants of animals treated with loxoribine and levamisole. The number of natural killer cells was significantly reduced in loxoribine-treated explants.

CONCLUSION(S)

Loxoribine, a potent immunomodulatory drug, appeared to cause regression in both stromal and epithelium components in a rat model of endometriosis. Further, specific cell-mediated immune responses in this model of endometriosis were elucidated.

Recombinant E-peptides of pro-IGF-I have mitogenic activity

In mammals, the post-translational proteolytic modification of many pro-hormones generates multiple peptides with similar or distinct biological activities. The production of mature insulin-like growth factor I (IGF-I) involves the cleavage of an E-peptide from pro-IGF-I. Although the IGF-I E-peptides are conserved among vertebrate species, their fate and biological roles have not been identified. To test whether the E-peptides possess any biological activity, three recombinant E-peptides of pro-IGF-I, namely Ea-2-, Ea-3- and Ea-4-peptides of rainbow trout, Oncorhynchus mykiss, were produced in vitro with a His-tag expression system and partially purified with an affinity Ni++ column. The mitogenic activity of each E-peptide was determined by (1) the stimulation of total DNA content increase as measured by a fluorometric method and/or (2) stimulation of [3H]-thymidine incorporation into DNA. Recombinant Ea-4-peptide elicited a dose-related increase in both mitogenic assays in NIH3T3 cells. To further test the specificity of the mitogenic activity of Ea-4-peptide, three other cell lines were used: retroviral transformed human embryonic kidney cells (293GP), human mammary gland tumor cells (MCF-7) and caprine mammary epithelial cells (CMEC). Similar levels of mitogenic activity were observed in all cell lines tested for Ea-4-peptide. Mitogenic activity was also observed with recombinant Ea-2- and Ea-3-peptides when assayed in NIH3T3 cells. These results suggest that E-peptides of rainbow trout pro-IGF-I possess mitogenic activity in heterologous systems.

Early embryonic expression of the growth hormone family protein genes in the developing rainbow trout, Oncorhynchus mykiss

In fish, growth hormone (GH), prolactin (PRL) and somatolactin (SL) are three major peptide hormones produced in the pituitary gland. Using reverse transcription-polymerase chain reaction (RT-PCR) and Southern blot analysis of the amplified products, the expression of GH, PRL, and SL genes were determined during the embryonic development in rainbow trout (Oncorhynchus mykiss). The mRNA for GH, PRL and SL were detected not only in embryos prior to or after organogenesis of the pituitary gland but also in mature oocytes as maternal messages. After hatching, all of these three mRNA species were detected at very high levels. Since the ontogenesis of the pituitary gland takes place on embryonic day (ED) 14, these observations suggest that the GH family protein genes are expressed in the developing embryos prior to the formation of the pituitary gland. Using the same RT-PCR assay, PRL mRNA was detected only in the head part of the fry whereas GH and SL mRNA were detected in both the head and trunk. In adult animals, though high levels of GH mRNA were primarily detected in the pituitary gland, brain, gill, and heart, low levels of GH mRNA were also detected in the kidney, liver, pyloric ceaca, and ovary. Results of the current study and those reported by Yang et al. (1997. Gen Comp Endocrinol 106:271-281) suggest that GH and SL genes are also expressed in extrapituitary tissues even after the organogenesis of the pituitary gland. Furthermore, these results suggest that these hormones may play important roles yet to be identified during embryonic development in fish.

Antibodies for Growth Hormone and Prolactin Using Multiple Antigen Peptide Immunogens

: Antibodies elicited by novel synthetic peptide antigens derived from a highly conserved domain of the growth hormone (GH) and prolactin (PRL) of vertebrates were developed using the multiple antigen peptide approach. The sequence of the antigens is located near the carboxy-terminus in the D domain of the GH and PRL in a cluster of 11 and 10 conserved amino acids, respectively, within a sequence of 18 residues. The synthetic peptides were manually synthesized, purified by high-performance liquid chromatography, and the corresponding antibodies, elicited in rabbits, were cross-reacted with the GH and PRL of a variety of mammalian (human, bovine, ovine, pig, and equine) and nonmammalian (chicken, coho salmon, chum salmon, rainbow trout, catfish and striped bass) vertebrates. The cross-reactivity between the immunogen and its corresponding antigen was tested by immunobloting using either GH or PRL. The GH and PRL of the organisms tested cross-reacted specifically with the corresponding antibody. Chicken and fish GH and PRL showed stronger antibody cross-reactivity than that observed in mammalian sources. These results demonstrate the utility of peptide-derived polyclonal antibodies in the detection of native and recombinant GH and PRL of a variety of vertebrates.

Interaction between estrogen receptor and Pit-1 protein is influenced by estrogen in pituitary cells

The estrogen responsiveness of the rat prolactin gene expression requires the presence of both the estrogen receptor (ER) and the tissue-specific transcription factor, Pit-1 protein. We performed protein interaction assays using anti-rat Pit-1 antiserum (a-rPit-1) to investigate the physical interactions which occur between ER and Pit-1 proteins following estrogen treatment. After fusing maltose binding protein (MBP) and Pit-1 protein, we used the resulting MBP Pit-1 fusion protein to prepare a-rPit-1. Our results show that the estrogen receptor readily co-precipitated with the Pit-1 protein drawn from the lysates of two prolactin-expressing pituitary cell lines GH3 and PR1. The rate of precipitation appears to be both estrogen- and time-dependent. Cellular levels of estrogen receptors and Pit-1 proteins did not show significant changes during the time of estrogen treatment. We therefore suggest that an estrogen-dependent physical interaction between ER and Pit-1 protein exists in vivo, and that this interaction may play an important role in the regulation of prolactin gene expression.

Optimal flexible designs in phase II clinical trials

In the conduct of a phase II cancer clinical trial, patients usually enter in two stages. If the response rate from the first stage is low, then the study terminates. Within various two-stage designs, Simon proposed the optimal and minimax criteria. In the co-operative group setting, practical considerations make it difficult to arrive at the planned sample size exactly. Green and Dahlberg proposed and compared several flexible designs. In this paper, we explicitly define a flexible design as a collection of two-stage designs where the first stage size is in a set of consecutive values (n1, ..., nk) and the second stage size is also in another set of consecutive values (N1, ..., Nk), and each of k2 possible designs has the same probability of occurrence. We apply Simon's optimal and minimax criteria to flexible designs for phase II trials in order to minimize the number of patients tested on an ineffective drug.

Transgenic fish and its application in basic and applied research

Since 1985, transgenic fish have been successfully produced by microinjecting or electroporating desired foreign DNA into unfertilized or newly fertilized eggs using many different fish species. More recently, transgenic fish have also been produced by infecting newly fertilized eggs with pantropic, defective retroviral vectors carrying desired foreign DNA. These transgenic fish can serve as excellent experimental models for basic scientific investigations as well as in biotechnological applications. In this paper, we will review the current status of the transgenic fish research and its potential application in basic and applied research.

Characterization of a teleost insulin-like growth factor II (IGF-II) gene: evidence for promoter CCAAT/enhancer-binding protein (C/EBP) sites, and the presence of hepatic C/EBP

Insulin-like growth factor I (IGF-I) and IGF-II, acting under the regulatory control of growth hormone, are the principal mediators of vertebrate growth. We have previously demonstrated that like humans, but unlike rodents, rainbow trout maintain high hepatic IGF-II messenger RNA levels into adulthood. Here we describe a rainbow trout IGF-II gene with a proximal promoter that contains two CCAAT/enhancer-binding protein (C/EBP) binding sites (TCBS1 and TCBS2). Nuclear proteins corresponding in size to rat C/EBPalpha and C/EBPbeta were detected on Western immunoblots of growth-hormone-treated and mock-treated trout liver extracts. Electrophoretic mobility shift assay of these nuclear extracts further suggests the presence of C/EBPs in trout liver and confirms the ability of TCBS1 to form a complex with trout liver nuclear proteins that is identical in mobility and specificity to that formed by a mammalian consensus CBS construct. In both Western blot and mobility assay results, the growth-hormone-treated trout livers appeared to have a greater accumulation of C/EBP, suggesting a molecular mechanism by which growth hormone can influence the level of serum IGF-II.

Characterization of a breast cancer cell line derived from a germ-line BRCA1 mutation carrier

A tumor cell line, HCC1937, was established from a primary breast carcinoma from a 24-year-old patient with a germ-line BRCA1 mutation. A corresponding B-lymphoblastoid cell line was established from the patient's peripheral blood lymphocytes. BRCA1 analysis revealed that the tumor cell line is homozygous for the BRCA1 5382insC mutation, whereas the patient's lymphocyte DNA is heterozygous for the same mutation, as are at least two other family members' lymphocyte DNA. The tumor cell line is marked by multiple additional genetic changes including a high degree of aneuploidy, an acquired mutation of TP53 with wild-type allele loss, an acquired homozygous deletion of the PTEN gene, and loss of heterozygosity at multiple loci known to be involved in the pathogenesis of breast cancer. Comparison of the primary tumor with the cell line revealed the same BRCA1 mutation and an identical pattern of allele loss at multiple loci, indicating that the cell line had maintained many of the properties of the original tumor. This breast tumor-derived cell line may provide a useful model system for the study of familial breast cancer pathogenesis and for elucidating BRCA1 function and localization.

Inhibition of DNA synthesis by RB: effects on G1/S transition and S-phase progression

The retinoblastoma tumor suppressor protein, RB, is a negative regulator of cell proliferation. Growth inhibitory activity of RB is attenuated by phosphorylation. Mutation of a combination of phosphorylation sites leads to a constitutively active RB. In Rat-1 cells, the phosphorylation-site-mutated (PSM)-RB, but not wild-type RB, can inhibit S-phase entry. In PSM-RB-arrested G1 cells, normal levels of cyclin E and cyclin E-associated kinase activity were detected, but the expression of cyclin A was inhibited. The ectopic expression of cyclin E restored cyclin A expression and drove the PSM-RB expressing cells into S phase. Interestingly, Rat-1 cells coexpressing cyclin E and PSM-RB could not complete DNA replication. Microinjection of cells that have passed through the G1 restriction point with plasmids expressing PSM-RB also led to the inhibition of DNA synthesis. The S-phase inhibitory activity of PSM-RB could be attenuated by the coinjection of SV40 T-antigen, adenovirus E1A, or a high level of E2F-1 expression plasmids. However, the S-phase inhibitory activity of PSM-RB could not be overcome by the coinjection of cyclin E or cyclin A expression plasmids. These results reveal a novel role for RB in the inhibition of S-phase progression that is distinct from the inhibition of the G1/S transition, and suggest that continued phosphorylation of RB beyond G1/S is required for the completion of DNA replication.

CPAN, a human nuclease regulated by the caspase-sensitive inhibitor DFF45

Induction of apoptosis by death receptors such as Fas or tumour necrosis factor (TNF) R1 leads to distinct changes in cell morphology, activation of the caspase protease cascade, and the degradation of nuclear chromatin by activated nucleases. Here, we describe the purification and cDNA cloning of a novel 40 kDa endonuclease from Jurkat cells that is activated by caspases. This protein, designated caspase-activated nuclease (CPAN), is sufficient to degrade naked DNA and to induce apoptotic morphology and DNA fragmentation in naive nuclei. CPAN is highly homologous to a recently described mouse nuclease, CAD [1], and may represent the human homologue. Our data on the human cDNA as well as additional data on the mouse homologue suggest that a 30 amino-acid portion of the recently published mouse sequence [1] is incorrect. We show that the activity of human CPAN is regulated by DFF45 [2], an inhibitor necessary for CPAN expression and stabilization in an inactive state in living cells. Proteolytic cleavage of DFF45 by caspases in vitro leads to dissociation of DFF45 fragments from CPAN and activation of CPAN as an endonuclease. CPAN is a tightly regulated endonuclease with unique characteristics that might represent a distinctive family of endonucleases.

Interaction of 2,2',4,4',5,5'-hexachlorobiphenyl with hepatic cytochrome P-4501A in rainbow trout (Oncorhynchus mykiss)

Di-ortho polychlorinated biphenyls (PCBs) are prominent environmental contaminants and their biological activity in fish may be more significant than previously thought. Four weeks after intraperitoneal (i.p.) injection with 50 or 250 microg 2,2',4,4',5,5'-hexachlorobiphenyl (2HxCB)/g fish, rainbow trout livers were removed and frozen at -80 degrees C or microsomes were prepared. Microsomal ethoxyresorufin O-deethylase (EROD) activity was approximately one and two orders of magnitude greater than controls in fish treated with 50 and 250 microg 2HxCB/g fish, respectively. Cytochrome P4501A (CYP1A) Western immunoblot relative optical density increased with 2HxCB dose. Hepatic CYP1A1 mRNA levels were approximately threefold greater in fish treated with 250 microg 2HxCB/g fish than in controls, while hepatic CYP1A1 mRNA levels in fish treated with 50 microg 2HxCB/g fish were not significantly induced. There was no increase of CYP1A3 mRNA in 2HxCB-treated fish. The study showed 2HxCB induced hepatic EROD activity, CYP1A protein, and CYP1A1 mRNA content in rainbow trout.

Effect of inline filtration on ViaSpan cold-storage solution

The effect of filtration on the particulate load in ViaSpan cold-storage solution was studied. Commercially available inline blood transfusion filters (SQ40S, Pall Biomedical) were inserted into the delivery-set port of polyvinyl chloride bags of ViaSpan (DuPont Merck Pharmaceutical). Particles in samples collected in particle-free vials before and after filtration were counted by a light-obscuration technique. The compatibility of key ViaSpan ingredients and of three commonly used additives (penicillin G potassium, dexamethasone sodium phosphate, and human insulin) with the inline filter was also investigated. Filtration removed 56% of particles 5-10 microm in diameter, 71% of particles of > 10-25 microm, and > 99% of particles measuring > 25 microm. Flow rates with the filters were more than adequate for clinical use. Concentrations of constituent hydroxyethyl starch, glutathione, adenosine, allopurinol, raffinose pentahydrate, and lactobionic acid were not significantly affected by filtration, nor were the concentrations of any of the drug additives. Inline filtration of ViaSpan effectively reduced fatty acid salt particulates in the solution and had no deleterious effect on flow rate, ingredient concentrations, or concentrations of commonly added drugs.

Optimal three-stage designs for phase II cancer clinical trials

The objective of a phase II cancer clinical trial is to screen a treatment that can produce a similar or better response rate compared to the current treatment results. This screening is usually carried out in two stages as proposed by Simon. For ineffective treatment, the trial should terminate at the first stage. Ensign et al. extended two-stage optimal designs to three stages; however, they restricted the rejection region in the first stage to be zero response, and the sample size to at least 5. This paper extends Simon's two-stage to a three-stage design without these restrictions, and provides tables for both optimal and minimax designs. One can use the three-stage design to reduce the expected sample size when the treatment is not promising a priori and when the accrual rate is slow. The average reduction in size from a two-stage to three-stage design is 10 per cent.

Pantropic retroviral vector integration, expression, and germline transmission in medaka (Oryzias latipes)

Pantropic retroviral vectors were used to introduce transgenes into Japanese medaka (Oryzias latipes). These vectors contain the long terminal repeat (LTR) sequence of Moloney murine leukemia virus (Mo-MLV) and a reporter gene (neo or lacZ) regulated by the LTR sequence of rous sarcoma virus (RSV). Because these pseudotyped retroviral vectors contain the vesicular stomatitis virus envelope glycoprotein (VSV-G), they have an extremely broad host cell range and can infect many no mammalian species. Newly fertilized medaka eggs (intact or dechorionated) were electroporated at different voltage settings in the presence of 4 x 10(4) cfu of pantropic retroviral vector. The survival rates of the pantropic retroviral vector-treated embryos ranged from 65% to 20% with increasing amplitude of electroporation. Dechorionation did not substantially affect the survival rate of embryos. PCR amplification demonstrated proviral sequences in up to 60% of the 2-month-old fish. The efficiency of gene transfer was enhanced by dechorionation. Furthermore, overnight incubation of dechorionated embryos with pantropic retroviral vectors without electroporation also resulted in proviral integration in 60% of the embryos without compromising survival rate. Southern blot analysis of DNA samples isolated from polymerase chain reaction (PCR) as positive F1 reaction animals confirmed the integration of a single copy of the provirus into the host genome. Three P1 transgenic females transmitted the proviral sequence to 50% of their F1 progeny in a back cross with wild-type males, suggesting that the entire germline of these P1 fish was transformed by the pantropic retroviral vector. Expression of the neomycin phosphotranferase transgene in F1 transgenic individuals was detected by reverse transcription (RT)-PCR amplification of the neo mRNA sequence. Furthermore, expression of a beta-galactosidase transgene was also observed in 4-day-old F1 transgenic individuals. Thus, pantropic retroviral vectors provide a convenient method to stably introduce and express foreign genes in medaka.

A thyroid hormone receptor coactivator negatively regulated by the retinoblastoma protein

The retinoblastoma protein (Rb) plays a critical role in cell proliferation, differentiation, and development. To decipher the mechanism of Rb function at the molecular level, we have systematically characterized a number of Rb-interacting proteins, among which is the clone C5 described here, which encodes a protein of 1,978 amino acids with an estimated molecular mass of 230 kDa. The corresponding gene was assigned to chromosome 14q31, the same region where genetic alterations have been associated with several abnormalities of thyroid hormone response. The protein uses two distinct regions to bind Rb and thyroid hormone receptor (TR), respectively, and thus was named Trip230. Trip230 binds to Rb independently of thyroid hormone while it forms a complex with TR in a thyroid hormone-dependent manner. Ectopic expression of the protein Trip230 in cells, but not a mutant form that does not bind to TR, enhances specifically TR-dependent transcriptional activity. Coexpression of wild-type Rb, but not mutant Rb that fails to bind to Trip230, inhibits such activity. These results not only identify a coactivator molecule that modulates TR activity, but also uncover a role for Rb in a pathway that responds to thyroid hormone.

Identification of immunodominant T cell epitopes of human glutamic acid decarboxylase 65 by using HLA-DR(alpha1*0101,beta1*0401) transgenic mice

Glutamic acid decarboxylase isoform 2 (GAD65; EC 4.1.1.15) has been identified as a key target autoantigen of insulin-dependent diabetes mellitus (IDDM). IDDM is genetically associated with the major histocompatibility complex (MHC), and particular alleles from the HLA-DQ and HLA-DR loci contribute to disease. Among DR4 subtypes, HLA-DRB1*0401, HLA-DRB1*0402, and HLA-DRB1*0405 alleles lend susceptibility, while HLA-DRB1*0403 confers protection. We have utilized HLA-DR(alpha1*0101,beta1*0401) (hereafter referred to as DR0401), human CD4, murine class II null triple transgenic mice and recombinant GAD65 to generate T cell hybridomas, and we have used overlapping sets of peptides to map the immunodominant epitopes of this autoantigen. We have identified 10 immunogenic regions for GAD65, of which 6 are recognized by multiple hybridomas. These epitopes are also generated by human antigen-presenting cells and their presentation is DR0401 restricted, as shown by the use of typed human lymphoblastoid cell lines and antibody blocking experiments. Immunodominant GAD65 epitopes defined in transgenic mice correspond to GAD65 regions previously shown to elicit T cell responses specifically in DR0401 IDDM patients, underscoring the validity of this approach. Interestingly, although the major epitopes contain DR0401 binding motifs, one of the epitopes contains a DR0405 motif.

Regulation of K3 keratin gene transcription by Sp1 and AP-2 in differentiating rabbit corneal epithelial cells

Rabbit corneal epithelial cells cultured in the presence of 3T3 feeder cells undergo biochemical differentiation, as evidenced by their initial expression of K5 and K14 keratins characteristic of basal keratinocytes, followed by the subsequent expression of K3 and K12 keratin markers of corneal epithelial differentiation. Previous data established that mutations of an Sp1 site in a DNA element, E, that contains overlapping Sp1 and AP-2 motifs reduce K3 gene promoter activity by 70% in transfection assays. We show here that Sp1 activates while AP-2 represses the K3 promoter. Although undifferentiated corneal epithelial basal cells express equal amounts of Sp1 and AP-2 DNA-binding activities, the differentiated cells down-regulate their Sp1 activity slightly but their AP-2 activity drastically, thus resulting in a six- to sevenfold increase in the Sp1/AP-2 ratio. This change coincides with the activation and suppression of the differentiation-related K3 gene and the basal cell-related K14 keratin gene, respectively. In addition, we show that polyamines, which are present in a high concentration in proliferating basal keratinocytes, can inhibit the binding of Sp1 to its cognate binding motif but not that of AP-2. These results suggest that the relatively low Sp1/AP-2 ratio as well as the polyamine-mediated inhibition of Sp1 binding to the E motif may account, in part, for the suppression of the K3 gene in corneal epithelial basal cells, while the elevated Sp1/AP-2 ratio may be involved in activating the K3 gene in differentiated corneal epithelial cells. Coupled with the previous demonstration that AP-2 activates the K14 gene in basal cells, the switch of the Sp1/AP-2 ratio during corneal epithelial differentiation may play a role in the reciprocal expression of the K3 and K14 genes in the basal and suprabasal cell layers.

Temporal expression pattern of insulin-like growth factor mRNA during embryonic development in a teleost, rainbow trout (Onchorynchus mykiss)

The appearance of insulin-like growth factor I (IGFI) and II (IGF-II) mRNA was studied during rainbow trout embryonic development. Reverse transcription-polymerase chain reaction (RT-PCR), followed by Southern blotting and high-stringency hybridization with rainbow trout IGF-I and IGF-II cDNA probes, was used to detect all four forms of IGF-I mRNA and one form of IGF-II mRNA from whole-embryo total RNA isolated from a staged series. IGF-I and IGF-II mRNA were detected in unfertilized eggs. IGF-I and IGF-II mRNA were also detected during cleavage, gastrulation, and organogenesis, at hatching, during yolk absorption, and at feeding. IGF-IEa-1 and Ea-3 mRNA were detected in unfertilized eggs, while IGF-I Ea-4 was first detected at stage 9 when the zygotic genome is believed to become activated in rainbow trout. IGF-IEa-2 was not detected at any stage of embryonic development. IGF mRNA of immunoreactive peptides have been detected durin embryonic development in all vertebrates studied to date. Our results confirm the presence of IGF-I mRNA in teleost embryos. In addition, IGF-II mRNA is also present in teleost embryos. Our results suggest that the role IGF-I and IGF-II play during embryonic development may be conserved in vertebrates.

Cloning and characterization of rainbow trout (Oncorhynchus mykiss) somatolactin cDNA and its expression in pituitary and nonpituitary tissues

A cDNA clone encoding rainbow trout (Oncorhynchus mykiss) somatolactin (rtSL) has been isolated from a rainbow trout pituitary cDNA library. This 2329-bp cDNA clone includes a very short 7-bp 5'-untranslated region, a coding region of 702 bp, and a long 3'-untranslated region of 1620 bp. The deduced amino acid sequence of rtSL shows a polypeptide of 233 amino acid residues which consists of a 24-amino-acid putative signal peptide followed by a 209-amino-acid mature polypeptide. This mature polypeptide has a molecular weight of 24 kDa. The rtSL shares 99% amino acid identity with chum salmon SL (csSL) and approximately 53-77% amino acid identity with SLs in other fishes, including the 7 conserved cysteine residues. Although a glycosylation site has been identified in SL of other fish species, none is observed in rtSL polypeptide. The level of rtSL mRNA in a single pituitary gland was determined by RNA blot hybridization. Results showed that levels of SL mRNA in pituitary glands of 2-year-old fish were 4- to 7-fold higher than those of 1-year-old fish. The tissue distribution of SL gene expression in adult fish was determined by reverse transcription-polymerase chain reaction (RT-PCR) and DNA blot hybridization. In addition to the pituitary gland, SL mRNA was detected in all tissues examined including brain, gill, heart, kidney, liver, skeleton muscle, spleen, ovary, testis, and immature oocytes. The extrapituitary expression of the SL gene was also detected in embryos and fry. The PCR products which contained the region coding for mature SL from heart and kidney were cloned and characterized. Nucleotide sequence analysis showed that the SL mRNAs in heart and kidney were identical to that in the pituitary gland. These results suggest that, although the pituitary gland is the predominant tissue for producing SL, it is not the only tissue that SL gene is expressed in, and the extrapituitary expression of rtSL gene starts from very early developmental stages.

Characterization of rainbow trout (Oncorhynchus mykiss) growth hormone 1 gene and the promoter region of growth hormone 2 gene

Studies by Agellon et al. (Mol. Reprod. Dev. 1, 11-17) showed the presence of two growth hormone (rtGH1 and rtGH2) mRNA species in pituitary glands of adult rainbow trout (Oncorhynchus mykiss). In this study, we have detected rtGH1 and rtGH2 mRNAs in pituitary glands of rainbow trout from fry to 2 years of age. The level of rtGH1 mRNA is notably higher than that of rtGH2 mRNA in 10-day-old fry and 2-year-old females. These results suggest differential expression of rtGH1 and rtGH2 genes in different sexes and developmental stages. As a step toward elucidating the mechanism of differential expression of both GH genes, DNA fragments encoding rtGH1 gene and the promoter/regulatory region of rtGH2 gene were isolated and characterized. Rainbow trout GH genes span approximately 4.5 kb and are composed of six exons and five introns. The 5'-flanking region of both genes contain consensus sequences for TATA boxes and several Pit-1 binding sequences. Consensus sequences related to the cAMP response element, thyroid hormone response element, retinoic acid response element, estrogen response element (ERE), and glucocorticoid response element are present not only in the 5'-flanking region, but also in introns and exons in rtGH1 gene. These hormone response elements, except ERE, are also present in rtGH2 gene.

Somatotropic actions of the homologous growth hormone and prolactins in the euryhaline teleost, the tilapia, Oreochromis mossambicus

It is increasingly clear that growth hormone (GH) has growth-promoting effects in fishes, which are mediated in part by the insulin-like growth factor (IGF)-I. Growth-promoting actions of prolactin (PRL) have been reported in higher vertebrates, but are less well established in teleosts. We examined the effects of injecting homologous GH or the two homologous tilapia PRLs (tPRL177 and tPRL188) on the in vitro incorporation of [35S] sulfate (extracellular matrix synthesis) and [3H]thymidine (DNA synthesis) by ceratobranchial cartilage explants and on IGF-I mRNA levels in tilapia liver. Tilapia GH (tGH) and tPRL177 stimulated sulfate uptake at the highest doses examined. Thymidine incorporation was stimulated by tPRL177. tPRL188 was without these effects. Consistent with its somatotropic actions, tGH elevated IGF-I mRNA levels in the liver. tPRL177 also elevated liver IGF-I levels. Consistent with the previously described osmoregulatory actions of GH and PRL in teleosts, we observed that tGH elevated and tPRL177 and tPRL188 lowered levels of gill Na+,K+-ATPase activity. High-affinity, low-capacity binding sites for tGH in the tilapia liver were identified. tPRL177 binds with lower affinity than tGH to these sites but can displace 125I-labeled tGH from its receptor. The ability of tPRL177 to displace tGH was similar to that of ovine GH. tPRL188 did not displace 125I-labeled tGH binding. Collectively, this work suggests that tPRL177 may possess somatotropic actions similar to tGH, but only in freshwater tilapia where tPRL177 levels are sufficiently high for it to act as a competitive ligand for GH receptors.

pp32 overexpression induces nuclear pleomorphism in rat prostatic carcinoma cells

Nuclear pleomorphism is an important diagnostic factor in tumour pathology. Traditionally, nuclear pleomorphism is evaluated qualitatively or semiquantitatively, often as a component of tumour grade; the molecular basis of nuclear pleomorphism, however, remains unclear. In this study, we investigated the quantitative effects on nuclear morphology of overexpressing pp32, a recently described nuclear phosphoprotein highly expressed in self-renewing and neoplastic cell populations. Assessment of Feulgen-stained transfected and control lines of AT3.1, a rat prostatic carcinoma cell line, using a computerized Cellular Image Analysis System (BD CAS-200) showed that stable overexpression of human pp32 in AT3.1 cells is accompanied by marked increases in the coefficient of variation of nuclear shape, nuclear size and chromatin textures but not in DNA content. In contrast, stable transfection with control vector, with ras, or with bcl-2 failed to affect nuclear morphology. Cell cycle analysis further showed that pp32-related increases in variation of nuclear structure manifested principally in G1. These studies suggest that pp32 plays a role either directly or indirectly in the control of nuclear shape of G1 cells.

Prosthetic valve endocarditis due to Legionella pneumophila

Prosthetic valve endocarditis is a potential complication of valve replacement surgery and warrants prompt diagnosis and appropriate treatment. Thus, the blood culture in addition to providing an etiological organism is important in establishing appropriate antibiotic therapy. A case of prosthetic valve endocarditis (PVE) is presented with repeatedly negative blood cultures at a community hospital and refractory to prolonged therapy with standard antibiotic regimens. Appropriate workup eventually identified the causative organism as Legionella pneumophila, and antimicrobial therapy directed against Legionella combined with a repeat valve replacement effectively treated this case. Aspects of culture-negative PVE including the microbiology and etiology are discussed. Legionella endocarditis represents an important cause of culture negative PVE and should be considered in the differential diagnosis of culture negative PVE refractory to standard antimicrobial therapy.

Three forms of gonadotropin-releasing hormone in a perciform fish (Sparus aurata): complementary deoxyribonucleic acid characterization and brain localization

Three forms of GnRH-salmon (sGnRH), seabream (sb-GnRH), and chicken (cGnRH-II)-have been described in the gilthead seabream (Sparus aurata) brain, and the cDNA encoding the sbGnRH precursor was recently isolated. In the present study, the cDNAs encoding the sGnRH and cGnRH-II were isolated and characterized, and the neurons producing the three GnRHs were localized in the seabream brain. Fragments of sGnRH and cGnRH-II cDNAs were amplified by polymerase chain reaction and used as probes to isolate the full-length cDNAs from a brain cDNA library. The cDNA encoding the cGnRH-II precursor is 573 nucleotides (nt) long, and the cDNA encoding the sGnRH precursor is 1971 nt in length with an unusually long 5' untranslated region. Specific single-strand DNA probes for in situ detection of mRNA were designed according to nonconserved regions among the three GnRH c-DNAs. Localization of GnRH mRNA-producing cells in the brain revealed five distinct populations of cells: sGnRH-producing cells in the ventromedial olfactory bulbs and the terminal nerve, sbGnRH-producing cells in the preoptic area and the ventral thalamus, and cGnRH-II-producing cells in the midbrain tegmentum. The discrete sites of expression of the three forms of GnRH indicate that only sbGnRH is directly involved in the control of gonadotropin secretion.

DNA immunization induces protective immunity against B-cell lymphoma

Idiotypic determinants of the immunoglobulin expressed on the surface of B-cell lymphomas are tumor-specific antigens (TSAs), which can be targeted by immunotherapy. Immunization with DNA constructs encoding the idiotype (ld) of a murine B-cell lymphoma induced specific anti-ld antibody responses and protected mice against tumor challenge. Use of DNA encoding an ld/GM-CSF (idiotype/granulocyte-macrophage colony-stimulating factor) fusion protein improved vaccine efficacy, and xenogeneic immunoglobulin constant region determinants were required for immunogenicity. These results indicate that DNA may be a simple and efficacious means of inducing immune responses against a weak, otherwise unrecognized tumor antigen, provided that additional stimuli are included with the DNA.

Production of transgenic dwarf surfclams, Mulinia lateralis, with pantropic retroviral vectors

A pantropic pseudotyped retroviral vector containing the envelope protein of vesicular stomatitis virus was used as a gene transfer vector in the dwarf surfclam, Mulinia lateralis. These pantropic retroviral vectors have an extremely broad host cell range and can infect many nonmammalian species. Newly fertilized dwarf surfclam eggs were electroporated at 700 V in the presence of 1 x 10(4) colony-forming units of pantropic pseudotyped retroviral particles. Infection was well tolerated and did not affect the survival rate of the embryos. Gametes collected from P1 presumptive transgenic animals were analyzed for the presence of provirus by PCR, and in different experiments 13-33% of the gamete pools were positive for the transgene. Dot blot hybridization of DNA samples from the F1 offspring of two different crosses between infected P1 and wild-type individuals revealed that 28% and 31% of F1 offspring were transgenic, respectively. Southern blot analysis of DNA isolated from PCR-positive F1 animals confirmed integration of a single copy of the provirus into the host genome. Thus, the germ lines of these two P1 transgenic animals were mosaic for the transgene. Expression of beta-galactosidase encoded by the provirus was detected in transgenic but not control surfclam embryos. Pantropic pseudotyped retroviral vectors provide a useful method for the stable introduction of foreign genetic information into surfclams and may facilitate the introduction of desirable genetic traits into commercially important shellfish and crustaceans.

IL-1 beta, TNF-alpha, and IL-2 in peritoneal fluid and macrophage-conditioned media of women with endometriosis

PROBLEM

The presence of various cytokines in human peritoneal fluid has been incompletely evaluated. Changes in cytokine levels may be related to the development of endometriosis, infertility, and activation of peritoneal macrophages. This study assesses levels of IL-1 beta, IL-2 and TNF- alpha in peritoneal fluid and macrophage conditioned media of women with endometriosis.

METHOD

Peritoneal fluid was collected from 51 women at the time of diagnostic or operative laparoscopy for benign gynecologic disease. Peritoneal macrophages were isolated, cultured for 24 h, and the culture media collected. IL-1 beta, IL-2, and TNF- alpha levels were determined by commercial ELISA kits.

RESULTS

The mean concentration of IL-1 beta and TNF- alpha was significantly higher in macrophage conditioned media of patients with endometriosis (P < 0.02). However, there were no significant changes in peritoneal fluid cytokine levels. Peritoneal macrophage concentrations were also higher in patients with endometriosis.

CONCLUSION

This study supports the concept that endometriosis is associated with activation of peritoneal macrophages, and a higher concentration of these cells. This activation is reflected by the increased levels of cytokines found in macrophage conditioned media. The absence of significant changes in peritoneal fluid cytokine levels would seen to indicate that the above derangements are not responsible for the development or progression of endometriosis.

Synergism of GH and IGF-I in stimulation of sulphate uptake by teleostean branchial cartilage in vitro

The combined effects of teleostean GH and human IGF-I in the regulation of teleost branchial cartilage growth were examined. Ceratobranchial cartilages were dissected from the common carp (Cyprinus carpio) and maintained in a defined culture medium supplemented with recombinant striped bass GH (sbGH), human IFG-I (hIGF-I) or both, and the uptake of [35S]sulphate by cartilage explants was measured. sbGH alone in the culture medium did not exhibit a significant stimulatory effect on the uptake of [35S]sulphate when compared with the controls. However, with hIGF-I in the culture medium, as low as 1 ng/ml, the stimulatory effect of sbGH was apparent and dose-dependent. The synergism of sbGH and hIGF-I was observed at the concentrations of 1 and 10 ng IGF-I/ml tested. At a constant hIGF-I concentration (10 ng/ml), a maximum stimulatory effect was detected with 3 micrograms recombinant sbGH/ml, at which point a 2.3-fold increase in sulphation activity was obtained when compared with the treatment with hIGF-I alone. A similar dose-dependent stimulatory effect was observed when native common carp and bonito GHs were tested using this assay system. These results suggest that the synergistic effect of sbGH and hIGF-I on sulphation activity is a common biological function of teleost GH, thus ruling out the possibility of experimental artifacts resulting from utilization of heterologous GH. Furthermore, experiments were conducted to test whether the synergism between sbGH and hIGF-I occurred between sbGH and insulin.(ABSTRACT TRUNCATED AT 250 WORDS)