Reduction of UV-induced skin tumors in hairless mice by selective COX-2 inhibition

UV light is a complete carcinogen, inducing both basal and squamous cell skin cancers. The work described uses the selective COX-2 inhibitor celecoxib to examine the efficacy of COX-2 inhibition in the reduction of UV light-induced skin tumor formation in hairless mice. UVA-340 sun lamps were chosen as a light source that effectively mimics the solar UVA and UVB spectrum. Hairless mice were irradiated for 5 days a week for a total dose of 2.62 J/cm(2). When 90% of the animals had at least one tumor, the mice were divided into two groups so that the tumor number and multiplicity were the same (P < 0.31). Half of the mice were then fed a diet containing 1500 p.p.m. celecoxib. Tumor number, multiplicity and size were then observed for the next 10 weeks. Ninety-five percent of the tumors formed were histopathologically evaluated as squamous cell carcinoma. COX-2 expression and activity were increased in tumors. After 10 weeks, the difference in tumor number and multiplicity in the drug-treated group was 56% of UV controls (P < 0.001). The results show that the orally administered selective COX-2 inhibitor celecoxib prevents new tumor formation after the onset of photocarcinogenesis and suggest that treatment with celecoxib may be very useful in preventing UV-induced skin tumors in humans.

Immunization with viruslike particles induces long-term protection of rabbits against challenge with cottontail rabbit papillomavirus

Rabbits were immunized with recombinant baculovirus-produced virus-like particles (VLPs) of cottontail rabbit papillomavirus (CRPV) to determine whether these antigens could induce long-term protection against experimental challenge with CRPV. Infectious CRPV and human papillomavirus type 11 L1 VLPs were used as positive and negative control immunogens, respectively. Three groups of immunized animals were challenged with 10-fold serial dilutions of infectious CRPV at 2 weeks, 6 months, and 12 months after immunizations. Antibody titers in serum reached 1:10,000 immediately after the final booster immunization and then decayed to 1:150 at 6 months and 1:100 at 12 months in unchallenged rabbits. Serum neutralization titers followed similar kinetics. Papillomas grew on control-immunized rabbits at sites challenged with 10(-1) (100% of sites), 10(-2) (96% of sites), 10(-3) (63% of sites), and 10(-4) (13% of sites) dilutions of virus. At 2 weeks after CRPV L1 VLP immunizations, the rabbits were completely protected against virus challenge. At both 6 and 12 months after CRPV L1 VLP immunizations, strong protection was also observed. In the last two groups, three of seven rabbits were completely protected and only 4 of 14 or 29% of sites challenged with 10(-1 dilution of virus grew papillomas. Papillomas growing at these four sites were also reduced in size (3.5 +/- 0.7 mm) at 50 days postchallenge compared with sites challenged with 10(-1) dilution on control-immunized rabbits (13.2 +/- 4.2 mm). The results demonstrate that strong and long-lasting protection against experimental challenge with papillomaviruses can be achieved with VLP immunogens.

Apolipoprotein A-I stimulates AMP-activated protein kinase and improves glucose metabolism

AIMS/HYPOTHESIS

In humans, one of the hallmarks of type 2 diabetes is a reduced plasma concentration of HDL and its major protein component, apolipoprotein A-I (APOA-I). However, it is unknown whether APOA-I directly protects against diabetes. The aim of this study was to characterise the functional role of APOA-I in glucose homeostasis.

METHODS

The effects of APOA-I on phosphorylation of AMP-activated protein kinase (AMPK) and acetyl-coenzyme A carboxylase (ACC), glucose uptake and endocytosis were analysed in C2C12 myocytes. Glucose metabolism was investigated in Apoa-I knockout (Apoa-I (-/-)) mice.

RESULTS

APOA-I was able to stimulate the phosphorylation of AMPK and ACC, and elevated glucose uptake in C2C12 myocytes. APOA-I could be endocytosed into C2C12 myotubes through a clathrin-dependent endocytotic process. Inhibition of endocytosis abrogated APOA-I-stimulated AMPK phosphorylation. In Apoa-I (-/-) mice, AMPK phosphorylation was reduced in skeletal muscle and liver, and expression of gluconeogenic enzymes was increased in liver. In addition, the Apoa-I (-/-) mice had increased fat content and compromised glucose tolerance.

CONCLUSIONS/INTERPRETATION

Our data indicate that APOA-I has a protective effect against diabetes via activation of AMPK. ApoA-I deletion in the mouse led to increased fat mass and impaired glucose tolerance.

Highlight on the studies of anticancer drugs derived from plants in China

Recent progress on the study of anticancer drugs originating from plants in China is reviewed in this paper. Guided by the experience of traditional Chinese medicine, several new drugs have been found. Indirubin from Indigofera tinctoria is useful for the treatment of chronic myelocytic leukemia. Irisquinone from Iris latea pallasii and 10-hydroxy camptothecin from Camptotheca accuminata have exhibited definite activity on rodent tumors. Recent studies indicate that ginsenoside Rh2 is an inducer of cell differentiation in melanoma B-16 cells in vitro. Pharmacological studies have demonstrated that curcumin from Curcuma longa is an antimutagen as well as an antipromotor for cancer. Daidzein and acetyl boswellic acid have been shown to be effective inducers of cell differentiation in HL-60 cells. Guided by the chemotaxonomic principle of plants, harringtonine and homoharringtonine isolated from Cephalotaxus hainanesis have exhibited significant antileukemia activity and are widely used in clinics in China. Taxol from Taxus chinensis has been shown to be an important new anticancer drug with unique chemical structure and mechanism of action. The continuous search for new anticancer drugs from plants will be a fruitful frontier in cancer treatment and chemoprevention.

Linkage of regression and malignant conversion of rabbit viral papillomas to MHC class II genes

Human papillomaviruses associated with cutaneous and anogenital cancers induce intraepithelial precursor lesions which may regress spontaneously or progress into invasive carcinomas. Cell-mediated immune responses are probably involved in regression of precancerous lesions and the polymorphism of the genes responsible may thus have a key role in the variability of the host response. Skin warts and cancers induced in rabbits by Shope papillomavirus provide a model to test this hypothesis. We analysed a restriction-fragment-length polymorphism of major histocompatibility complex class I and class II genes and T-cell receptor beta-chain genes in infected domestic rabbits. We found a strong linkage between wart regression and a DR alpha EcoRI fragment, and an increased relative risk of malignant transformation associated with a DQ alpha PvuII fragment. This indicates a genetic control of wart evolution, involving genes in the class II region of the major histocompatibility complex.

Pathogenicity, development, and reproduction of Heterorhabditis bacteriophora and Steinernema carpocapsae under axenic in vivo conditions

Galleria mellonella larvae cultured axenically were treated with axenic dauer juveniles of Heterorhabditis bacteriophora and Steinernema carpocapsae. After 3 days S. carpocapsae had killed all insects, with 9.4 +/- 4.3 nematodes per larva. H. bacteriophora were unable to kill G. mellonella, although 13.3 +/- 6.4 nematodes per Galleria were found in the hemocoel. Invading nematodes of both strains recovered from the dauer stage. H. bacteriophora developed into hermaphrodites with eggs and J1 in the uterus and in the hemolymph of the living insects. Development beyond the J1 stage was not recorded. An injection of supernatants from different Photorhabdus luminescens cultures killed the insects but could not provide nutrients to support a further development. Only the injection of bacterial cells supported production of dauers in the axenic insects. Axenic S. carpocapsae developed to adults and produced offspring. After 3 weeks an average of 5275 nematodes per larva were counted, of which 6.7% were dauer juveniles, 39.2% other juvenile stages, 11.9% males, and 42.2% females. Compared to in vivo reproduction in the presence of the symbiotic bacterium Xenorhabdus nematophilus the dauer juvenile yields were low. Even after 5 weeks the percentage of dauer juveniles did not surpass 10%.

Pull-off Force Measurements between Rough Surfaces by Atomic Force Microscopy

Direct measurements of the pull-off (adhesion) forces between pharmaceutical particles (beclomethasone dipropionate, a peptide-type material, and lactose) with irregular geometry and rough polymeric surfaces (series of polypropylene coatings, polycarbonate, and acrylonitrile-butadiene-styrene) were carried out using the atomic force microscope. These measurements showed that roughness of the interacting surfaces is the significant factor affecting experimentally measured pull-off forces. A broad distribution of pull-off force values was noted in the measurements, caused by a varying adhesive contact area for a particle located on rough substrate. The possibility of multiple points of contact between irregularly shaped pharmaceutical particles and substrate surfaces is demonstrated with nanoindentations of the particle in a fluoro-polymer film. Force-distance curves showing the "sawtooth" pattern are additional evidence that particles make contact with substrates at more than one point. Reduced adhesion of 10- to 14-microm-diameter lactose and peptide material particles to the polypropylene coatings with a roughness of 194 nm was found in this study. Similar pull-off force versus roughness relationships are also reported for the model spherical particles, silanized glass particle with a size of 10 microm and polystyrene particle with a diameter of 9 microm, in contact with polypropylene coatings of varying roughness characteristics. It was found that the model recently proposed by Rabinovich et al. (J. Colloid Interface Sci. 232, 1-16 (2000)) closely predicts the pull-off forces for glass and lactose particles. On the other hand, the adhesion of the peptide material and polystyrene particle to polypropylene is underestimated by about an order of magnitude with the theoretical model, in which the interacting substrates are treated as rigid materials. The underestimate is attributed to the deformation of the peptide material and polystyrene particles.

Resveratrol, a natural aryl hydrocarbon receptor antagonist, protects sperm from DNA damage and apoptosis caused by benzo(a)pyrene

Benzo(a)pyrene (BaP), an aryl hydrocarbon receptor (AhR) ligand present in cigarette smoke and car exhaust, is thought to have negative effects on male reproduction. We hypothesized that BaP damages sperm through AhR activation, phase I enzyme induction, DNA adduct formation, and increased germ cell apoptosis in the testis, and that resveratrol, a natural competitive inhibitor of the AhR found in some red wines, could prevent the adverse effects of BaP on sperm. Male Balb C mice were injected subcutaneously (s.c.) for 5 weeks with a range of BaP doses (0.5 mg/kg to 50 mg/kg). Live sperm were obtained from the vas deferens, counted, and stained to measure annexin-V positive (apoptotic) cells. In a subsequent study, mice were injected for 5 weeks with corn oil (control), BaP (5 mg/kg/week), or BaP plus resveratrol (50 mg/kg/week) (n = 3 per group). Immunohistochemistry (IHC) was performed on testis sections for the determination of CYP1A1, BaP diol epoxide (BPDE) DNA adducts, and apoptosis and the results quantified by using the HSCORE, a semiquantitative scoring system. Our results demonstrated that sperm counts after 5 weeks were inversely correlated to BaP dosage. BaP (0.5 to 5 mg/week) positively correlated with sperm apoptosis while higher doses increased sperm necrosis. CYP1A1 protein was observed mainly in interstitial cells of some testis sections, but there was no significant induction by BaP. BPDE DNA adducts were induced in all components of the seminiferous tubules by BaP and suppressed by resveratrol: median HSCORE (interquartile range) control 61 (52-71.5); BaP 213 (192-248), P = 0.01 compared to control; BaP plus resveratrol 83 (70-90). BaP significantly increased apoptosis, mainly in spermatogonia: medain HSCORE (interquartile range) BaP 189 (161-223) versus control 83 (57-93), P < 0.01; and this effect was abrogated by resveratrol. Median HSCORE for BaP plus resveratrol was 112 (range 99-121). In summary, BaP caused increased sperm cell BPDE DNA adduct formation and apoptosis in the mouse. The natural AhR antagonist, resveratrol diminished BaP-induced DNA adducts and apoptosis in seminiferous tubules.

Boswellic acid acetate induces differentiation and apoptosis in leukemia cell lines

Boswellic acid acetate (BC-4), a compound isolated from the herb Boswellia carterii Birdw., can induce differentiation and apoptosis of leukemia cells. Based on cell morphology and NBT reduction, BC-4 induced monocytic differentiation of myeloid leukemia HL-60, U937 and ML-1 cells at a dose under 12.5 microg/ml (24.2 microM). BC-4 was a potent inducer, with 90% of the cells showing morphologic changes and 80-90% of the cells showing NBT reduction. Specific and non-specific esterase were also increased by BC-4. Based on benzidine staining assay, BC-4 failed to induce erythroid leukemia DS-19 and K562 cells differentiation. In contrast to its selective differentiation effect, BC-4 strongly inhibited growth of all cell lines tested. The growth inhibition effect was dose- and time-dependent. In HL-60 cells, 20 microg/ml (38.8 microM) of BC-4 decreased viable cell number by 60% at 24 h, whereas at 3 days there was virtually no viable cells. Morphologic and DNA fragmentation analysis proved that BC-4 induced cell apoptosis. The dual apoptotic and differentiation effects of BC-4 suggest that it may be a powerful agent in the treatment of leukemia.

Protease-activated receptor 2, a receptor involved in melanosome transfer, is upregulated in human skin by ultraviolet irradiation

Previous studies have shown that the protease-activated receptor 2 is involved in skin pigmentation through increased phagocytosis of melanosomes by keratinocytes. Ultraviolet irradiation is a potent stimulus for melanosome transfer. We show that protease-activated receptor 2 expression in human skin is upregulated by ultraviolet irradiation. Subjects with skin type I, II, or III were exposed to two or three minimal erythema doses of irradiation from a solar simulator. Biopsies were taken from nonexposed and irradiated skin 24 and 96 h after irradiation and protease-activated receptor 2 expression was detected using immunohistochemical staining. In nonirradiated skin, protease-activated receptor 2 expression was confined to keratinocytes in the lower one-third of the epidermis. After ultraviolet irradiation protease-activated receptor 2 expression was observed in keratinocytes in the upper two-thirds of the epidermis or the entire epidermis at both time points studied. Subjects with skin type I showed delayed upregulation of protease-activated receptor 2 expression, however, compared with subjects with skin types II and III. Irradiated cultured human keratinocytes showed upregulation in protease-activated receptor 2 expression as determined by immunofluorescence microscopy and Western blotting. Cell culture supernatants from irradiated keratinocytes also exhibited a dose-dependent increase in protease-activated receptor-2 cleavage activity. These results suggest an important role for protease-activated receptor-2 in pigmentation in vivo. Differences in protease-activated receptor 2 regulation in type I skin compared with skin types II and III suggest a potential mechanism for differences in tanning in subjects with different skin types.

Class-specific histone/protein deacetylase inhibition protects against renal ischemia reperfusion injury and fibrosis formation

Renal ischemia-reperfusion injury (IRI) is a common cause of renal dysfunction and renal failure. Histone/protein deacetylases (HDACs) regulate gene accessibility and higher order protein structures and may alter cellular responses to a variety of stresses. We investigated whether use of pan- and class-specific HDAC inhibitors (HDACi) could improve IRI tolerance in the kidney. Using a model of unilateral renal IRI, we investigated early renal function after IRI, and calculated fibrosis after IRI using an automated scoring system. We found that pan-HDAC inhibition using trichostatin (TSA) yielded significant renal functional benefit at 24-96 hours (p < 0.001). Treated mice developed significantly less fibrosis at 30 days (p < 0.0004). Class I HDAC inhibition with MS-275 yielded similar effects. Protection from fibrosis formation was also noted in a cold ischemia transplant model (p < 0.008) with a trend toward improved cold ischemic survival in TSA-treated mice. These effects were not accompanied by induction of typical ischemic tolerance pathways or by priming of heat shock protein expression. In fact, heat shock protein 70 deletion or overexpression did not alter renal ischemia tolerance. Micro-RNA 21, known to be enhanced in vitro in renal tubular cells that survive stress, was enhanced by treatment with HDACi, pointing to possible mechanism.

Focal adhesion kinase is a key mediator of human trophoblast development

Trophoblast differentiation during the first trimester of pregnancy involves cell proliferation and invasion and extracellular matrix (ECM) remodeling. Reports have indicated that, in a variety of cell types, processes such as proliferation, invasion, and ECM remodeling require the turnover of focal adhesions mediated by a cytoplasmic tyrosine kinase named focal adhesion kinase (FAK). Therefore, in the present study we examined the expression and spatial localization of FAK during early human placental development. Immunocytochemical and immunoblot analysis showed that FAK and a focal adhesion-associated protein named paxillin were highly expressed between the 5th and 8th weeks of gestation, specifically in villous cytotrophoblast and extravillous trophoblast (EVT) cells. Activated FAK, phosphorylated on Tyr-397, colocalized with alpha5 integrin and matrix metalloproteinase-2 (MMP2) expression in EVT cells within a previously characterized intermediate, invasive-restrained region. FAK and paxillin expression dramatically decreased after 10 to 12 weeks of gestation coincident with increasing pO(2) levels. Exposure of human villous explants of 5 to 8 weeks to a 3% O(2) environment resulted in increased trophoblast outgrowth, cell proliferation, and detection of alpha5 integrin and MMP2, as well as increased activation of FAK in EVT cells compared with explants grown in a 20% O(2) environment. To determine whether FAK was a key requisite for trophoblast differentiation, villous explants of 5 weeks gestation were grown in Matrigel in a 3% O(2) environment and incubated with 20-mer antisense FAK oligonucleotides. A dramatic reduction of trophoblast outgrowth was observed in antisense-treated explants compared with missense and control cultures, and, in addition, cell proliferation and MMP2 activity in antisense-treated explants were dramatically reduced. These data suggest that FAK is a key kinase involved in early trophoblast cell differentiation and plays a role in regulating cell proliferation and motility during early placental development.

Histone/protein deacetylase inhibitor therapy for enhancement of Foxp3+ T-regulatory cell function posttransplantation

T-regulatory (Treg) cells are like other cells present throughout the body in being subject to biochemical modifications in response to extracellular signals. An important component of these responses involves changes in posttranslational modifications (PTMs) of histones and many nonhistone proteins, including phosphorylation/dephosphorylation, ubiquitination/deubiquitination, and acetylation/deacetylation. Foxp3, the key transcription factor of Tregs, is constantly being rapidly turned over, and a number of these PTMs determine its level of expression and activity. Of interest in the transplant setting, modulation of the acetylation or deacetylation of key lysine residues in Foxp3 can promote the stability and function, leading to increased Treg production and increased Treg suppressive activity. This mini-review focuses on recent data concerning the roles that histone/protein deacetylases (HDACs) play in control of Treg function, and how small molecule HDAC inhibitors can be used to promote Treg-dependent allograft survival in experimental models. These data are discussed in the light of increasing interest in the identification and clinical evaluation of isoform-selective HDAC inhibitors, and their potential application as tools to modulate Foxp3+ Treg cell numbers and function in transplant recipients.

miR-383 inhibits ovarian cancer cell proliferation, invasion and aerobic glycolysis by targeting LDHA

MicroRNAs (miRNAs) are differentially expressed in various cancers and act as oncogenes or tumor suppressors. MiR-383 has been characterized as a cancer suppressor in several cancers. However, the exact expression patterns of miR-383 and the precise molecular mechanisms underlying its role in ovarian cancer have not been investigated thoroughly. In this study, we found that the expression of miR-383 was significantly downregulated in ovarian cancer tissues and ovarian cancer cell lines. Ectopic expression of miR-383 remarkably suppressed the ovarian cancer cell proliferation by enhancing cell apoptosis and significantly inhibited the invasion of ovarian cancer cells, while low expression of miR-383 exhibited the opposite effect. Bioinformatics analysis suggested LDHA as a novel target of miR-383, and miR-383 suppressed the expression level of LDHA mRNA by direct binding to its 3'-untranslated region (3'UTR). Expression of miR-383 was negatively correlated with LDHA in ovarian cancer tissues. In addition, modulation of miR-383 expression could affect the aerobic glycolysis in the ovarian cancer cells. Furthermore, Silencing of LDHA counteracted the effects of miR-383 suppression, while its overexpression reversed tumor inhibitory effects of miR-383. In conclusion, our study demonstrated that miR-383 regulated LDHA expression in ovarian cancer cells, thereby stunting glycolysis, cell proliferation and invasion.

Protection of rabbits from viral challenge by gene gun-based intracutaneous vaccination with a combination of cottontail rabbit papillomavirus E1, E2, E6, and E7 genes

In this study, cottontail rabbit papillomavirus infection of domestic rabbits was used as an animal model to develop papillomavirus early gene-based vaccines. Groups of rabbits were intracutaneously vaccinated with single papillomavirus early genes E1, E2, E6, and E7 or with a combination of these four genes. Only a fraction of rabbits were protected from subsequent viral challenge when vaccinated with the E1 or E6 gene. Viral tumor growth in those rabbits vaccinated with the E1 or E2 gene was suppressed compared to that in controls. In contrast, seven of nine rabbits vaccinated with the combination of the E1, E2, E6, and E7 genes were completely protected against viral challenge. These data indicated that intracutaneous genetic vaccination with the combination of the E1, E2, E6, and E7 genes can be an effective strategy for immunoprophylaxis of papillomavirus infection.

DNA vaccination prevents and/or delays carcinoma development of papillomavirus-induced skin papillomas on rabbits

Malignant progression is a life-threatening consequence of human papillomavirus-associated lesions. In this study, we tested the efficacy of papillomavirus early-gene-based vaccines for prevention of carcinoma development of papillomavirus-induced skin papillomas on rabbits. Rabbit skin papillomas were initiated by infection with cottontail rabbit papillomavirus (CRPV). The papillomas were allowed to grow for 3 months without any treatment intervention. Rabbits were then immunized by gene gun-mediated intracutaneous administration of four DNA plasmids encoding CRPV E1, E2, E6, and E7 genes, respectively. All eight control rabbits receiving vector alone developed invasive carcinoma within 8 to 13 months. In contrast, only two of eight vaccinated rabbits developed carcinoma at 12 and 15 months, respectively. Papilloma growth was suppressed in the majority of vaccinated rabbits but not completely eradicated. These results indicate that gene gun-mediated immunization with papillomavirus early genes may be a promising strategy for prevention of malignant progression of human papillomavirus-associated lesions in humans.

Dexmedetomidine post-treatment induces neuroprotection via activation of extracellular signal-regulated kinase in rats with subarachnoid haemorrhage

BACKGROUND

Dexmedetomidine, a sedative agent, provides neuroprotection when administered during or before brain ischaemia. This study was designed to determine whether dexmedetomidine post-treatment induces neuroprotection against subarachnoid haemorrhage (SAH) and the mechanisms for this effect.

METHODS

Subarachnoid haemorrhage was induced by endovascular perforation to the junction of the right middle and anterior cerebral arteries in adult rats. Dexmedetomidine was applied immediately or 2 h after onset of SAH. Neurological outcome was evaluated 2 days after SAH. Right frontal cortex area 1 was harvested 24 h after SAH for western blotting.

RESULTS

Subarachnoid haemorrhage reduced neurological scores and increased brain oedema and blood-brain barrier permeability. These effects were attenuated by dexmedetomidine post-treatment. Neuroprotection by dexmedetomidine was abolished by PD98095, an inhibitor of extracellular signal-regulated kinase (ERK) activation. Phospho-ERK, the activated form of ERK, was increased by dexmedetomidine; this activation was inhibited by PD98095.

CONCLUSIONS

Dexmedetomidine post-treatment provides neuroprotection against SAH. This effect appears to be mediated by ERK.

Effect of Photorhabdus luminescens phase variants on the in vivo and in vitro development and reproduction of the entomopathogenic nematodes Heterorhabditis bacteriophora and Steinernema carpocapsae

Photorhabdus luminescens (Enterobacteriaceae) is a symbiont of entomopathogenic nematodes Heterorhabditis spp. (Nematoda: Rhabditida) used for biological control of insect pests. For industrial mass production, the nematodes are produced in liquid media, pre-incubated with their bacterial symbiont, which provides nutrients essential for the nematode's development and reproduction. Particularly under in vitro conditions, P. luminescens produces phase variants, which do not allow normal nematode development. The phase variants were distinguished based on dye absorption, pigmentation, production of antibiotic substances, occurrence of crystalline inclusion proteins and bioluminescence. To understand the significance of the phase shift for the symbiotic interaction between the bacterium and the nematode, feeding experiments tested the effect of homologous and heterologous P. luminescens phase variants isolated from a Chinese Heterorhabditis bacteriophora (HO6), the Heterorhabditis megidis type strain from Ohio (HNA) and the type strain of Heterorhabditis indica (LN2) on the in vivo and in vitro development and reproduction of the nematode species H. bacteriophora (strain HO6) and another rhabditid and entomopathogenic nematode, Steinernema carpocapsae (A24). In axenically cultured insect larvae (Galleria mellonella) and in vitro in liquid media, H. bacteriophora produced offspring on phase I of its homologous symbiont and on the heterologous symbiont of H. megidis, but not on the two corresponding phase II variants. In solid media, nematode yields were much lower on phase II than on phase I variants. On the heterologous phase I symbiont isolated from H. indica the development of H. bacteriophora was not beyond the fourth juvenile stage of the nematode in any of the media tested, but further progressed on phase II with even a small amount of offspring recorded in solid media. Infective juveniles of S. carpocapsae did not develop beyond the J3 stage on all phase I P. luminescens. They died in phase I P. luminescens isolated from H. bacteriophora. Development to adults was recorded for S. carpocapsae on all phase II symbionts and offspring were produced in all media except in liquid. It is concluded that a lack of essential nutrients or the production of toxins is not responsible for the negative impact of homologous phase II symbiont cells on the development and reproduction of H. bacteriophora. The infective juveniles of H. bacteriophora retained cells of the homologous phase I symbiont, but not phase II cells and cells from heterologous symbionts, indicating that the transmission of the symbiont by the infective juvenile is selective for phase I cells and the homologous bacterial associate.

Immunization of rabbits with cottontail rabbit papillomavirus E1 and E2 genes: protective immunity induced by gene gun-mediated intracutaneous delivery but not by intramuscular injection

We previously demonstrated that gene gun-based intracutaneous vaccination of rabbits with a combination of, but not with individual papillomavirus E1, E2, E6 and E7 genes provided complete protection against cottontail rabbit papillomavirus (CRPV) infection. In the present study, we tested whether vaccination of inbred and outbred rabbits with a combination of CRPV E1 and E2 genes could provide complete protection against virus infection. In the first experiment, gene gun-based intracutaneous vaccination with E1 and E2 genes prevented papilloma formation in the majority of inbred rabbits and promoted systemic papilloma regression in one non-protected rabbit. In contrast, needle-mediated intramuscular injection of E1 and E2 genes did not prevent papilloma formation nor promoted systemic papilloma regression, indicating an absence of strong protective immunity. In the second experiment, six outbred rabbits were immunized by gene gun-based intracutaneous administration of the E1 and E2 genes. Prevention of papilloma formation or systemic papilloma regression was observed in three vaccinated rabbits. Papillomas persisted on the remaining three rabbits, but were significantly smaller than that on control rabbits. These results suggested that gene gun-based intracutaneous vaccination with the combination of papillomavirus E1 and E2 genes induced strong protective antivirus immunity but may be insufficient for complete protection in an outbred population.

Bladder irrigation specimens assayed by fluorescence in situ hybridization to interphase nuclei

Bladder irrigation specimens provide a sampling of the entire bladder urothelium and are the most practical sample for longitudinally monitoring patients. This study presents cross-sectional fluorescence in situ hybridization (FISH) analyses with correlated DNA cytometry data on 76 patients monitored for recurrent bladder tumors. FISH probes complementary to centromeric satellite sequences for chromosomes 1, 7, 9, 11, 15, and 17 were used. Aberrations in copy number were observed for chromosomes 1, 7, 11, and 17 principally in patients with aneuploid tumors. Monosomy of chromosome 9 was observed in 39% of the diploid and 31% of the specimens with high hyperdiploid fraction. Significantly, 24% of patients with a history of bladder cancer but with no clinical evidence of disease exhibited monosomy of chromosome 9. This suggests a persistent and significantly large population of abnormal cells in the absence of clinical evidence of disease. Loss of chromosome 9 relative to DNA ploidy was observed in 24% of patients with no evidence of disease, in 59% of patients with tumor, and in 79% of patients with histologically confirmed transitional cell carcinoma, grades 1-3. Loss of chromosome 15 was also observed in a large percentage of patients. Loss of chromosome 15 was observed in 41% of specimens from patients in whom no tumor was seen, in 38% of specimens from patients with tumor, and in 67% of specimens from patients with histologically confirmed transitional cell carcinoma. Results of this study document the use of bladder irrigation specimens as a specimen source for FISH analyses.(ABSTRACT TRUNCATED AT 250 WORDS)