Identification of trait-improving quantitative trait loci for grain yield components from a dent corn inbred line in an advanced backcross BC2F2 population and comparison with its F2:3 population in popcorn

Normal maize germplasm could be used to improve the grain yield of popcorn inbreds. Our first objective was to locate genetic factors associated with trait variation and make first assessment on the efficiency of advanced backcross quantitative trait locus (AB-QTL) analysis for the identification and transfer of favorable QTL alleles for grain yield components from the dent corn inbred. A second objective was to compare the detection of QTL in the BC2F2 population with results using F(2:3) lines of the same parents. Two hundred and twenty selected BC2F2 families developed from a cross between Dan232 and an elite popcorn inbred N04 were evaluated for six grain yield components under two environments, and genotyped by means of 170 SSR markers. Using composite interval mapping (CIM), a total of 19 significant QTL were detected. Eighteen QTL had favorable alleles contributed by the dent corn parent Dan232. Sixteen of these favorable QTL alleles were not in the same or near marker intervals with QTL for popping characteristics. Six QTL were also detected in the F(2:3) population. Improved N04 could be developed from 210 and 208 families with higher grain weight per plant and/or 100-grain weight, respectively, and 35 families with the same or higher popping expansion volume than N04. In addition, near isogenic lines containing detected QTL (QTL-NILs) for grain weight per plant and/or 100-grain weight could be obtained from 12 families. Our study demonstrated that the AB-QTL method can be applied to identify and manipulate favorable QTL alleles from normal corn inbreds and combine QTL detection and popcorn breeding efficiently.

Effects of fermented soybean meal on digestive enzyme activities and intestinal morphology in broilers

The experiment was performed to compare the effects of fermented soybean meal (fermented with Aspergillus oryzae 3.042, FSBM) and soybean meal on digestive enzyme activities and intestinal morphology in broilers. Three hundred twenty 1-d-old Ross x Ross male broiler chicks were randomly allocated into 2 dietary treatments for a 6-wk feeding trial, including 0- to 21-d and 21- to 42-d periods. At the end of each stage, 8 broilers of each treatment were killed, and pancreas, small intestine digesta, and duodenum, jejunum, and ileum segments were collected for digestive enzymes and intestinal morphology evaluation. Results of the experiment showed that replacing soybean meal with FSBM in diet increased the activities of trypsin, lipase, and protease significantly in intestinal content of starter broilers (P<0.05) and enhanced the protease activity of grower broilers (P<0.05). Amylase activity was not affected in both feeding periods by the treatments. Compared with the control, broilers fed with FSBM had lower pancreatic trypsin activity (P<0.05) in the starter phase. There were no significant differences on lipase, amylase, and protease activity between the treatments in both growth phases. Increased villus height (P<0.05) and decreased crypt depth (P<0.05) of jejunum mucosa could be observed in the whole growth stage of broilers fed with FSBM. Also, duodenal villus height of starter chicks was also significantly increased (P<0.05).

Blockage of intermediate-conductance-Ca(2+) -activated K(+) channels inhibits progression of human endometrial cancer

Potassium (K(+)) channels have been implicated in proliferation of some tumor cells. However, whether K(+) channels are important to the pathogenesis of endometrial cancer (EC) remains unknown. In the present study, we report that intermediate-conductance Ca(2+)-activated K(+) (IKCa1) channels play a critical role in the development of EC. The expression of IKCa1 at both mRNA and protein levels in EC tissues was greatly increased than that in atypical hyperplasia and normal tissues. Treatment of EC cells with clotrimazole and TRAM-34, two agents known to inhibit IKCa1 channels, suppressed the proliferation of EC cells and blocked EC cell cycle at G(0)/G(1) phase. Similarly, downregulation of IKCa1 by siRNA against IKCa1 inhibited EC cell proliferation and arrested its cell cycle at G(0)/G(1) phase. A clotrimazole-sensitive K(+) current was induced in EC cells in response to the increased Ca(2+). The current density induced by Ca(2+) was greatly reduced by clotrimazole, TRAM-34, charybdotoxin or downregulation of IKCa1 by the siRNA against IKCa1. Furthermore, TRAM-34 and clotrimazole slowed the formation in nude mice of tumor generated by injection of EC cells. Our results suggest that increased activity of IKCa1 channel is necessary for the development of EC.

Three-dimensional dynamical measurement of upper limb support during paraplegic walking

Functional electrical stimulation (FES) has been employed in paraplegic rehabilitation to resume their walking ability. However, there is less quantitative assessment method of FES walking efficiency and rehabilitation progress. This paper presents a new dynamical measurement of upper limb support force during paraplegic walking, which can be used to calculate the 3-D handle reaction vector (HRV). HRV may provide an assessment of FES-assisted efficiency. With a series of tests, the measurement accuracy, nonlinearity, and crosstalk of the designed system are testified. The force measurement error is found below 1.01%, while nonlinearity and crosstalk are less than 2.90%, and 3.19%, respectively. This means that the implemented walker system is reliable for the measurement of HRV during FES-assisted walking. A clinical trial is performed with a paraplegic subject. With the monitoring of FES-assisted walking, the downward component of HRV is found to decrease, implying the decreasing force generated from lower limb. The decrease slope in downward load curve can indirectly indicate the FES efficiency change during walking. The experiment and clinical trial results show that a 3-D dynamical measurement system is successfully accomplished to indirectly assess FES efficiency of lower limbs using quantitated forces applied by the upper limbs of paraplegic patients.

Effect of Cadmium in Feed on Organs and Meat Colour of Growing Pigs

One hundred and ninety-two barrows (Duroc x Landrace x Yorkshire, initial weight 27.7 kg) were used to investigate the effects of cadmium in feed on the function of selected organs and meat colour of growing pigs. The pigs were randomly allocated into four different treatments. Each treatment included three replications with 16 pigs per replicate. The animals were fed corn-soybean basal diet and supplemented with 0, 0.5, 5.0, 10.0 mg/kg cadmium (as CdCl(2)), respectively. The feeding trial ended when the average body weight of the pigs reach 90 kg. The results showed that, compared with controls, addition of 10 mg/kg cadmium to the diet resulted in significant elevations of relative weight of liver and spleen by 18.3% (p<0.05) and 19.7% (p<0.05) respectively, and of serum glutamic-pyruvic transaminase (GPT) and glutamic-oxaloacetic transaminase (GOT) activities by 17.8% (p<0.05) and 27.4% (p<0.05) respectively; and significant decreases of Na(+)/K(+)-ATPase activity in the liver by 24.6% (p<0.05), the redness of longissimus dorsi by 26.6% (p<0.05) and 24.9% (p<0.05) at 0.75 h and 16 h post mortem, respectively, and of the myoglobin content of longissimus dorsi by 19.4% (p<0.05). No changes were found in these indices above when the pigs were fed the diet supplied with 0.5 or 5 mg/kg cadmium (p>0.05), nor in renal functions among cadmium-treatment treatments (p>0.05) as indicated is the activities of urinary N-acetyl-beta-D-glucosaminidase (NAG) and alkaline phosphatase (ALP) and the content of urinary protein. The study indicated the adverse effects of 10 mg/kg cadmium in feed on liver functions and meat colour of growing pigs.

Effects of dietary copper (II) sulfate and copper proteinate on performance and blood indexes of copper status in growing pigs

160 crossbred (Duroc x Landrace x Yorkshire) gilts averaged 21.25 kg body weight were used to study the effects of dietary copper (II) sulfate (CuSO4) and copper proteinate (Cu-Pr) on growth performance, plasma Cu concentration, ceruloplasmin activity, and erythrocyte Cu/Zn-superoxide dismutase (SOD) activity. All pigs were allotted to four treatments and fed with basal diets supplemented with 0 (control), 250 mg /kg Cu as CuSO4, and 50 and 100 mg/kg Cu as Cu-Pr. Growth performance was determined based on two growth phase (phase 1: days 0 to 15, phase 2: days 15 to 30). After 30 days of the treatment, 16 pig blood samples (four per treatment) were collected for indexes of copper status determination. The experimental results showed that compared with control, pigs fed with 250 mg Cu/kg as CuSO4 and 100 mg Cu/kg as Cu-Pr had higher average daily gain and average daily feed intake in the whole growth phase (d 0 to 30). In addition, 250 mg Cu/kg as CuSO4 and 100 mg/kg Cu as Cu-Pr enhanced plasma ceruloplasmin activity (P < 0.05), and 100 mg/kg Cu as Cu-Pr increased erythrocyte Cu/Zn-SOD activity (P < 0.01) compared with the control. There was no obvious treatment response on plasma Cu concentration in the present study.

Development and assessment of conventional and targeted drug combinations for use in the treatment of aggressive breast cancers

Combination chemotherapy has been at the forefront of cancer treatment for over 40 years. However, the rationale for selecting drug combinations and the process used to demonstrate clinical effectiveness has primarily followed trial and error methodology. Typically, the selection and assessment of combined drug therapies has been based on the effectiveness of each agent as monotherapy in treating the neoplasm and avoiding overlapping toxicities, followed by clinical trials to establish dose scheduling, toxicity, and efficacy. Unfortunately, this scheme is inefficient in terms of the time required to complete and revise these clinical trials based on the outcome to optimize the drug combination. A more rational approach for the development of combination oncology products should consider (i) in vitro assays for assessing therapeutic effects of drug combinations (antagonistic, additive or synergistic interactions) when added simultaneously; (ii) methods for measuring these interactions in vivo; (iii) the importance of understanding pharmacokinetic and biodistribution parameters when using drug combinations; (iv) the need to assess pathways known to contribute to cancer cell survival as well as metastasis; and (iv) the need to assess the fate of different cell populations (cancer and stroma) contributing to the development of cancer. Therefore, the goal of this article is to provide a road map for the preclinical development of drug combination products that will have improved therapeutic activity and a high likelihood of providing beneficial therapeutic outcomes in patients with aggressive cancers with a specific focus on patients with breast cancer.

High-level of xylanase production by the thermophilic Paecilomyces themophila J18 on wheat straw in solid-state fermentation

The production of extracellular xylanase by a newly isolated thermophilic fungus, Paecilomyces themophila J18, on the lignocellulosic materials was studied in solid-state fermentation (SSF). The strain grew well at 50 degrees C and produced a high-level of xylanase activity using the selected lignocellulosic materials, especially wheat straw. Production of xylanase by P. themophila J18 on wheat straw was enhanced by optimizing the particle size of wheat straw, nitrogen source, initial moisture level, growth temperature and initial pH of the culture medium. Under the optimized conditions, yield as high as 18,580 Ug(-1) of carbon source of xylanase was achieved. No CMCase activity was observed. The xylanase exhibited remarkable stability and retained more than 50% of its original activity at 70 degrees C for 4h at pH 7.0-8.0. Therefore, P. themophila J18 could to be a promising microorganism for thermostable, cellulase-free xylanase production in SSF.

Effects of cadmium on serum sex hormone levels in pigs

An inhibition of sex hormone secretion is observed in domestic animals exposed to cadmium in experimental conditions. Ninety-six gilts (Duroc x Landrace x Yorkshire, initial weight 27.59 kg) were randomly assigned into four different groups with three replications in each group (eight gilts per replication). The groups received the corn-soybean basal diet and supplemented with 0, 0.5, 5.0 and 10.0 mg/kg cadmium (as CdCl2) respectively. The feeding trial was ended when body weight of pigs was approximately 90 kg. The results showed that 10.0 mg/kg cadmium significantly decreased average daily gain (p < 0.05) and increased feed/gain ratio (p < 0.05) of pigs. Follicle-stimulating hormone, luteinizing hormone, oestradiol (E2) and progesterone levels in serum of the pigs fed the diet supplemented with 10.0 mg/kg cadmium were lower significantly than those of the control (p < 0.05). Compared with the control, no changes were found in the levels mentioned above when the pigs fed the diet supplemented with 0.5 or 5.0 mg/kg cadmium (p > 0.05). The changes of regulatory mechanism of the pituitary-ovary axis may be the result of cadmium accumulation in pituitary and ovary and should be investigated further.

Inhibition of hepatocarcinoma by systemic delivery of Apoptin gene via the hepatic asialoglycoprotein receptor

Specificity is a prerequisite for systemic gene therapy of hepatocarcinoma. In vitro, the tumor-specific viral death effector Apoptin selectively induces apoptosis in malignant hepatic cells. Intratumoral treatment of xenografted subcutaneous hepatomas with Apoptin results in tumor regression. Here, we report a systemic delivery vehicle containing the Apoptin gene linked to asialoglycoprotein (Asor), which targets asialoglycoprotein receptor (ASGPR) present only on the surface of hepatocytes. In vitro, the protein-DNA complex Asor-Apoptin induced apoptosis in HepG2 hepatocarcinoma cells but not in normal L-02 hepatocytes. Non-hepatocyte-derived tumorigenic human A549 cells lacking the membrane ASGPR were not affected by Asor-Apoptin. In vivo systemic delivery of Asor-Apoptin via the tail vein into mice bearing in situ hepatocarcinoma resulted in specific and efficient distribution of Apoptin in both hepatocarcinoma cells and normal hepatocytes. Five days after injection of Asor-Apoptin, the in situ hepatocarcinomas showed significant signs of regression, whereas the surrounding normal hepatocytes did not. Systemically delivered Asor-LacZ expressing non-apoptotic LacZ gene did not inhibit tumor growth. Our data reveal that systemic delivery of Asor-Apoptin specifically induces apoptosis in malignant hepatocytes and thus constitutes a powerful and safe therapeutics against hepatocarcinomas.

Effect of excessive dietary fluoride on nutrient digestibility and retention of iron, copper, zinc, and manganese in growing pigs

Ninety-six crossbred growing pigs were used to evaluate the effects of fluoride levels on growth performance, nutrient digestibility, and the retention of minerals in tissues. Four dietary treatments were formulated by supplementing fluorine (as NaF) to a corn-soybean basal diet (39.75 mg/kg F) to provide the following added fluorine levels: 0, 50, 100, and 150 mg/kg fluorine. The results showed pigs of the 100 and 150 mg/kg fluorine-added groups had decreased average daily gain (ADG) and increased feed gain ratio (F/G) compared to the control (p < 0.05). Apparent digestibility of protein and calcium in 100 and 150 mg/kg fluorine-treated groups was significantly lower than that of the control (p < 0.05). On the other hand, iron, copper, zinc, and manganese levels in most tissues of the 100 and 150 mg/kg fluorine groups were markedly changed compared to the control (p < 0.05). However, growth performance, nutrient digestibility, and mineral concentrations in all tissues of pigs were not significantly affected by the addition of 50 mg/kg fluorine (p > 0.05). Thus, this study suggested that excess fluoride levels could decrease growth performance and change the retention of iron, copper, zinc, and manganese in pigs.

Pharmacokinetics and tissue distribution of zidovudine in rats following intravenous administration of zidovudine myristate loaded liposomes

Liposomes accumulating in the reticuloendothelial system (RES) appear to be a promising vehicle to improve the therapeutic index of anti-HIV drugs such as zidovudine (AZT). Since the entrapment efficiency of AZT in liposomes was found to be low and AZT leakage from liposomes is fast, zidovudine myristate (AZT-M) was synthesized as a prodrug, and AZT-M incorporated liposomes in a lyophilized form were prepared with an average diameter of 90 nm and an encapsulation efficiency of 98% after reconstitution. The pharmacokinetic profiles and tissue distribution of AZT after i.v. administration of AZT-M liposomes in rats were investigated, and the results were compared with those after i.v. administration of AZT solution. AZT levels in plasma were significantly higher following application of AZT-M liposomes compared with AZT solution, and AUC0_infinity increased from 5.0 +/- 0.7 micromol x min x ml(-1) to 8.2 +/- 1.7 micromol x min x ml(-1) accordingly. Tissue distribution studies also confirmed higher concentrations of AZT in organs of RES and brain, suggesting that AZT-M liposomes might be promising candidates for therapy of HIV infections.

The Ontogeny of the Urogenital System of the Spotted Hyena (Crocuta crocuta Erxleben)1

Studies were conducted to elucidate the importance of androgen-mediated induction of the extreme masculinization of the external genitalia in female spotted hyenas. Phallic size and shape; androgen receptor (AR) and alpha-actin expression; and sex-specific differences in phallic retractor musculature, erectile tissue, tunica albuginea, and urethra/urogenital sinus were examined in male and female fetuses from Day 30 of gestation to term. Similar outcomes were assessed in fetuses from dams treated with an AR blocker and a 5alpha-reductase inhibitor (antiandrogen treatment). Clitoral and penile development were already advanced at Day 30 of gestation and grossly indistinguishable between male and female fetuses throughout pregnancy. Sex-specific differences in internal phallic organization were evident at Gestational Day 45, coincident with AR expression and testicular differentiation. Antiandrogen treatment inhibited prostatic development in males and effectively feminized internal penile anatomy. We conclude that gross masculinization of phallic size and shape of male and female fetuses is androgen-independent, but that sexual dimorphism of internal phallic structure is dependent on fetal testicular androgens acting via AR in the relevant cells/tissues. Androgens secreted by the maternal ovaries and metabolized by the placenta do not appear to be involved in gross masculinization or in most of the sex differences in internal phallic structure.

Increased circulating endothelins are not of cardiopulmonary origin in heart failure patients

OBJECTIVE

Plasma concentrations of endothelin-1 and big-endothelin are increased in heart failure patients. However, the precise contribution of endothelin secretion from the cardiopulmonary system remains unresolved. The aim of this study was to investigate whether the cardiopulmonary system contributes to the circulating endothelin-1 and big-endothelin concentrations in heart failure patients.

MATERIAL AND METHODS

Blood samples were obtained at right heart catheterization from different cardiovascular regions including the coronary sinus in chronic heart failure patients (n=12) and from age-matched control subjects (n=12).

RESULTS

The peripheral plasma concentrations of endothelin-1 were almost 3-fold higher in heart failure patients compared with the control subjects (1.25 pmol/l, 0.30-8.20 pmol/l (median, range) versus 0.46 pmol/l, 0.10-0.88 pmol/l, p<0.01). However, the endothelin-1 concentration was approximately 25% lower in plasma samples from the coronary sinus than in plasma from the inferior caval vein (p<0.05) in the heart failure patients. There were no differences in big-endothelin concentrations between any of the cardiovascular regions.

CONCLUSIONS

In heart failure patients, increased plasma concentrations of endothelin-1 and big-endothelin mainly reflect an increased secretion from the peripheral endothelium.

Colchicine and 2-methoxyestradiol Inhibit Human Angiogenesis

BACKGROUND

Angiogenesis is a critical determinant of tumor growth and the development of metastases. Tubulin inhibitors have been shown to be effective inhibitors of angiogenesis. We hypothesized that colchicine, a well-know tubulin inhibitor and 2-methoxyestradiol (2 MeOH), a novel tubulin inhibitor, would limit the initiation of a human angiogenic response and would limit subsequent neovessel growth in a dose-dependent manner.

METHODS

To test this hypothesis, we cultured full-thickness human placental vein discs from three placentas in a fibrin-thrombin clot model. Both colchicine and 2 MeOH were tested over a wide range of concentrations (10(-6) to 10(-12) M) to determine their effect on the percent of wells that initiated an angiogenic response (%I) and the subsequent growth (Angiogenic Index, 0-16 range) of vein-derived neovessels.

RESULTS

Colchicine at doses of 10(-6) and 10(-8) M completely inhibited the angiogenic response (CI: 95%, P < 0.0001) but lower (10(-10) to 10(-12) M) doses did not significantly inhibit angiogenesis (P = NS). Effective in vitro colchicine levels far exceed achievable non-toxic human plasma levels. In contrast, 2-methoxyestradiol decreased initiation and angiogenic growth significantly at 10(-6) M (CI: 95%, P < 0.0001), but did not significantly decrease angiogenesis at doses of 10(-8), 10(-10), or 10(-12) M. In contrast to colchicine, human plasma levels of 10(-6) M 2 MeOH are achievable clinically with little or no associated toxicity.

CONCLUSIONS

Effective in vitro drug levels of 2 MeOH can be achieved in vivo, suggesting that 2 MeOH may have a role in the clinical treatment of angiogenesis-dependent diseases.

Establishment of subrenal capsule xenografts of primary human ovarian tumors in SCID mice: potential models

OBJECTIVE

To evaluate subrenal capsule xenografting of primary ovarian tumor tissues in mice for development of new ovarian cancer models.

METHODS

Pieces (1 x 3 x 3 mm) of ovarian tumor specimens from patients were meticulously grafted under renal capsules of female NOD/SCID mice within 2 h of surgical removal. Tumor types included papillary serous adenocarcinomas, borderline and benign mucinous cystadenomas, granulosa cell tumors, a serous borderline tumor and a grade 3 mixed surface epithelial tumor of transitional and undifferentiated types. After 1-2 months, grafts were retrieved for comparison with original tissues. Hematoxylin and eosin (H&E) and immunohistochemical staining was carried out using tissue micro-arrays and CEA, B72.3, WT-1, OC125, keratin, inhibin, CK7, CK20, Cam5.2, and MIB-1 as markers.

RESULTS

Tumor tissue engraftment rate was > 95%. Comparison of donor and post-graft tissues showed highly similar histopathological features; 91 +/- 5% concordance in immunostaining indicated major preservation of immunophenotypes in the xenografts for 30-60 days. There was a small, but significant, increase in MIB-1 proliferative index in xenografts compared to original specimens.

CONCLUSIONS

Subrenal capsule xenografts of primary human ovarian tumors in SCID mice can retain major histopathological and immunohistochemical characteristics of the original tissues. The achievable, consistently high engraftment rate allows use of such xenografts as tools for studying a wide range of ovarian tumors, including granulosa cell tumors and benign, borderline, and malignant surface epithelial neoplasms. Potential applications include preclinical testing of patients' tumor responses to various chemotherapeutic regimens, evaluation of novel therapeutic agents, analysis of tumor progression at cellular and molecular levels, and identification of new therapeutic targets.

Hormonal, cellular, and molecular regulation of normal and neoplastic prostatic development

This review on normal and neoplastic growth of the prostate emphasizes the importance of epithelial-mesenchymal/stromal interactions. Accordingly, during prostatic development urogenital sinus mesenchyme (a) specifies prostatic epithelial identity, (b) induces epithelial bud formation, (c) elicits prostatic bud growth and regulates ductal branching, (d) promotes differentiation of a secretory epithelium, and (e) specifies the types of secretory proteins expressed. In reciprocal fashion, prostatic epithelium induces smooth muscle differentiation in the mesenchyme. Epithelial-mesenchymal interactions during development continue postnatally into adulthood as stromal-epithelial interactions which play a homeostatic role and in so doing reciprocally maintain epithelial and stromal differentiation and growth-quiescence. Prostatic carcinogenesis involves perturbation of these reciprocal homeostatic cell-cell interactions. The central role of mesenchyme in prostatic epithelial development has been firmly established through analysis of tissue recombinants composed of androgen-receptor-positive wild-type mesenchyme and androgen-receptor-negative epithelium. These studies revealed that at the very least ductal morphogenesis, epithelial cytodifferentiation, epithelial apoptosis and epithelial proliferation are regulated by stromal and not epithelial androgen receptors. Likewise, progression from non-tumorigenesis to tumorigenesis elicited by testosterone plus estradiol proceeds via paracrine mechanisms. Thus, stromal-epithelial interactions play critical roles in the hormonal, cellular, and molecular regulation of normal and neoplastic prostatic development.

Effects on growth and cadmium residues from feeding cadmium-added diets with and without montmorillonite nanocomposite to growing pigs

One hundred and ninety-two crossbred pigs (barrows, Duroc x Landrace x Yorkshine, initial weight 27.6 kg) were used to evaluate the effects of montmorillonite nanocomposite (MNC) on cadmium (Cd) retention in tissues of growing pigs. The animals were randomly assigned to 2 supplementations of Cd (0 or 10 mg/kg) and 2 levels of MNC (0 or 0.5%) in a 2x2 factorial arrangement. Each group was fed corn-soybean basal diets and consisted of 3 replications of 16 pigs. The feeding experiment lasted 83 d. Pig growth performances decreased significantly by addition of 10 mg Cd/kg (p<0.05) and improved with supplementation of MNC (p<0.05). Addition of MNC with Cd decreased Cd retentions in muscle, liver, kidney, spleen, thymus and lymphaden of pigs (p<0.05). MNC also decreased tissue Cd residues of pigs fed the diet without added Cd (p>0.05). There were decreased iron levels and increased copper levels in serum and liver of 10 mg Cd/kg treatment (p<0.05). Zinc content in serum and liver was not affected by the addition of Cd (p>0.05). Serum and liver iron, copper and zinc concentrations of pigs fed MNC without added Cd were unaffected by MNC (p>0.05).

Mechanically evoked reflex electrogenic chloride secretion in rat distal colon is triggered by endogenous nucleotides acting at P2Y1, P2Y2, and P2Y4 receptors

Mechanical activation of the mucosal lining of the colon by brush stroking elicits an intestinal neural reflex and an increase in short circuit current (Isc) indicative of electrogenic chloride ion transport. We tested whether endogenous nucleotides are physiologic regulators of mucosal reflexes that control ion transport. The brush stroking-evoked Isc response in mucosa and submucosa preparations (M-SMP) of rat colon was reduced by the P2Y1 receptor (R) antagonist 2'deoxy-N6-methyl adenosine 3',5'-diphosphate diammonium salt (MRS 2179) and further blocked by tetrodotoxin (TTX). M-SMP Isc responses to serosal application of the P2Y1 R agonist 2-methylthioadenosine-diphosphate (2MeSADP) or the P2Y2/P2Y4 R agonist 5'uridine-triphosphate (UTP) were reduced but not abolished by TTX. The potency profile of nucleotides for increasing Isc was 5'adenosine-triphosphate (ATP; effective concentration at half maximal response [EC50] 0.65 x 10(4) M) congruent with UTP (EC50 1.0 x 10(-4) M) congruent with 2MeSADP (EC50 = 1.60 x 10(-4) M). Mucosal touch and distention-induced Ca2+ transients in submucous neurons were reduced by apyrase and prevented by blocking the P2Y1 R with MRS 2179 and TTX; denervation of the mucosa. It did not occur by touching a ganglion directly. 2MeSADP Ca2+ responses occurred in subsets of neurons with or without substance P (SP) responses. The potency profile of nucleotides on the neural Ca2+ response was 2MeSADP (5 x 10(-7) M) > UTP (6 x 10(-6) M) > ATP (9 x 10(-5) M). The expression of P2Y R immunoreactivity (ir) in nerve cell bodies was in the order of P2Y1 R > P2Y4 R >> P2Y2 R. P2Y1R ir occurred in the cell somas of more than 90% of neuronal nitric oxide synthase, vasoactive intestinal peptide (VIP), calretinin, or neuropeptide Y (NPY)-ir neurons, 78% of somatostatin neurons, but not in calbindin or SP neurons. P2Y2 R ir was expressed in a minority of SP, VIP, NPY, vesicular acetylcholine transporter, and calcitonin gene-related peptide-ir varicose fibers (5-20%) and those surrounding calbindin (5-20%) neurons. P2Y4 ir occurred mainly in the cell somas of 93% of NPY neurons. Reverse transcriptase polymerase chain reaction of the submucosa demonstrated mRNA for P2Y1R, P2Y2, P2Y4, P2Y6, and P2Y12 Rs. Expression of P2Y1, P2Y2, and P2Y4 protein was confirmed by western blots. In conclusion, endogenous nucleotides acting at P2YRs transduce mechanically evoked reflex chloride ion transport in rat distal colon. Nucleotides evoke reflexes by acting primarily at postsynaptic P2Y1 Rs and P2Y4 R on VIP+/NPY+ secretomotor neurons, at P2Y2 Rs on no more than 2% of VIP+ secretomotor neurons, and 2Y2 Rs mainly of extrinsic varicose fibers surrounding putative intrinsic primary afferent and secretomotor neurons. During mucosal mechanical reflexes, it is postulated that P2Y1 R, P2Y2 R, and P2Y4 R are activated by endogenous ATP, UTP, and 5'uridine-diphosphate.

Mechanical stimulation releases nucleotides that activate P2Y1 receptors to trigger neural reflex chloride secretion in guinea pig distal colon

Stroking the mucosal lining of the guinea pig colon with a brush elicits an intestinal neural reflex, and an increase in short-circuit current (Isc) indicative of chloride secretion. We tested whether endogenous and exogenous nucleotides are physiologic regulators of mucosal reflexes that modulate chloride secretion. The basal Isc was augmented by 6-N,N-diethyl-beta,gamma-dibromomethylene-D-adenosine-5'-triphosphate (ARL67156) inhibition of nucleotide breakdown or adenosine A1 receptor blockade and reduced by apyrase inactivation of nucleotidases, P2 receptor antagonists, tetrodotoxin (TTX), or piroxicam. ARL67156 augmented, and apyrase inhibited, stroking-evoked Isc responses. TTX and atropine inhibited nucleotide-evoked Isc responses. The agonist potency profile for Isc, 2-methylthioadenosine-diphosphate (2MeSADP) = 2-methioadenosine-triphosphate >> 5'adenosine-triphosphate (ATP) > or = 5'adenosine-diphosphate > 5'uridine-triphosphate > or = 5'uridine-diphosphate, supports a P2Y1 receptor (R). The P2 receptor antagonists suramin and pyridoxalphosphate-6-azophenyl-2'4'-disulfonic acid, reduced stroking responses (36%) and their effects were additive. The selective P2Y1 R antagonist, 2'deoxy-N6-methyl adenosine 3',5'-diphosphate diammonium salt, reduced stroking (54%) and 2MeSADP (70%) responses at P2Y1 Rs. The P2X1/3 R agonist, alpha,betaMeATP, increased Isc. A desensitizing dose of alpha,betaMeATP reduced stroking Isc responses but did not prevent the 2MeSADP-evoked Isc response. Reverse transcriptase polymerase chain reaction analysis revealed mRNAs for P2Y1 R, P2Y2 R, P2Y4 R, P2Y6 R, and P2Y12 R in submucosa. The expression of P2Y R immunoreactivity (ir) in cell bodies of submucous neurons followed the order of P2Y1 = P2Y2 >> P2Y4 R ir; P2Y1 Rs and P2Y2 R ir were abundant (21-50% of neurons). P2Y1 R ir was abundant in cholinergic secretomotor neurons and fewer than 2% of neuropeptide Y (NPY)/choline acetyltransferase secretomotor neurons, and P2Y2 R ir was expressed in virtually all NPY secretomotor neurons and approximately 30% of calbindin/intrinsic primary afferent neurons. P2Y4 R ir was present in NPY-positive neurons. P2Y ir was rare or absent in varicose nerve fibers. The functional data support the hypothesis that mechanical stimulation with a brush releases nucleotides that act predominantly at P2Y1 Rs and to a lesser extent on P2X1/3 Rs to mediate reflex chloride secretion. A separate P2Y2 R neural circuit pathway exists that is not activated by mechanical forces. Other receptors including P2Y4, P2Y6, P2Y12, or P4 Rs cannot be excluded.

Variation in ovarian morphology in four species of New World moles with a peniform clitoris

Female moles of the Old World genus Talpa display a curious suite of reproductive features that include a peniform clitoris and ovaries with a discrete interstitial gland or testis-like region (so-called 'ovotestes'). The masculinization of the female external genitalia in Talpa has accordingly been linked with secretion of androgens from the interstitial gland region of the fetal gonad. Although their ovarian morphology has received less attention, some species of New World moles also have ovaries with a pronounced interstitial gland (for example star-nosed mole, Condylura cristata), whereas females of other species do not (for example eastern mole, Scalopus aquaticus). Although it is difficult to determine the sex of both Old and New World moles, published accounts describing the external genitalia of female moles are available only for Talpa. The hypothesis that masculinization of the female external genitalia in moles is associated with the presence of an ovarian interstitial gland (OIG) was tested in the present study by using a comparative approach to determine whether these features are ever found in isolation of one another. Three genera of North American moles (Scapanus, Condylura and Neurotrichus) were studied and a peniform clitoris was found in all three species, but OIG were found in only two of three genera. The ovaries of S. latimanus and S. orarius were unremarkable, with no evidence of a discrete interstitial gland or testis-like region. Mapping these results onto recent talpid phylogenies indicates that loss of the bipolar ovarian morphology is a derived trait in Scapanus, and conclusively demonstrates that masculinization of the external genitalia in female moles can develop in the presence or absence of 'ovotestes'.

Role of the stromal microenvironment in carcinogenesis of the prostate

The topic of this review is the role of stromal-epithelial interactions in normal and malignant prostatic growth. Because cell-cell interactions and androgens play such key roles in the prostate, the goal of this review will be to apply endocrinologic and developmental concepts to the understanding of normal and malignant prostatic growth. Prostatic development is induced by androgens, which act via androgen receptors. Androgens elicit prostatic epithelial growth during fetal and prepubertal periods, and in adulthood androgens act via reciprocal homeostatic stromal-epithelial interactions to maintain functional differentiation and growth quiescence. During carcinogenesis, these reciprocal homeostatic stromal-epithelial interactions are disrupted. In this review, 2 models of prostatic carcinogenesis will be reviewed, both of which emphasize the role of the stromal microenvironment in the carcinogenic process. Hormonal carcinogenesis of the prostate can be elicited by treatment of rats and mice with testosterone plus estradiol (T+E2). Using an immortalized but nontumorigenic human prostatic epithelial cell line (BPH-1), tissue recombinant studies were employed to explore the cellular mechanisms of prostatic carcinogenesis. Accordingly, human BPH-1 prostatic epithelial cells were combined with rat UGM, and the resultant UGM+BPH-1 recombinants were grown in adult male nude mouse hosts. In untreated mouse hosts, UGM+BPH-1 recombinants produced solid branched epithelial cords and ductal structures exhibiting benign growth. In T+E2-treated hosts, UGM+BPH-1 recombinants formed invasive carcinomas. Since BPH-1 cells lack androgen and estrogen receptors, whereas rat UGM expresses both of these receptors, it is proposed that hormonal carcinogenesis is elicited by T+E2 via paracrine mechanisms mediated by the stromal microenvironment. During prostatic carcinogenesis in rats and humans, the periepithelial stroma undergoes progressive loss in smooth muscle with the appearance of carcinoma-associated fibroblasts (CAFs). This abnormal stroma was shown to promote carcinogenesis in genetically abnormal but nontumorigenic epithelial cells. CAF+BPH-1 tissue recombinants grown in male hosts formed carcinomas, whereas benign growth and orderly tissue architecture developed in recombinants composed of normal prostatic stroma+BPH-1. Malignant transformation triggered by CAF was associated with additional genetic alterations and changes in gene expression in the BPH-1 cells. Thus, the stromal microenvironment is a critical determinant of benign versus malignant growth.

Effect of dietary rare earth elements on growth performance and blood parameters of rats

Rare earth elements (REE) have been shown to influence growth performance in animal production, especially in pigs. In the present study, the effect of oral administration of rare earth elements on growing rats was investigated. Pure LaCl3 or an REE mixture containing 38% of LaCl3, 52% of CeCl3, 3% of PrCl3 and 7% of chlorides of other REE were used at two different concentrations as supplements to the diets. Fifty male Wistar rats at 4 weeks of age were allotted to five experimental groups: a control group; a La-low group and a La-high group with 75 and 150 mg/kg LaCl3.6H2O, respectively; a REE-low and an REE-high group with 75 and 150 mg/kg REE mixture, respectively. The animals were housed in individual pens. Feed and water were provided ad libitum. After 18 days the oral supplementation of LaCl3.6H2O or of the REE mixture improved daily body weight gain (BWG) by up to 5 or 9% (p > 0.05), respectively. LaCl3.6H2O as well as the REE mixture had positive effects (p < 0.05) on feed conversion ratio (FCR) with a decreased ratio by up to 8 and 11%, respectively. Supplementation of REE also had clear effects on blood serum parameters. The activities of alkaline phosphatase (AP) and alanine amino transferase (ALT) increased significantly (p < 0.05). At the same time, blood glucose level decreased and blood creatine level increased significantly (p < 0.05). There was no significant difference in cholesterol, total protein, albumin and urea nitrogen among the groups. There was no significant difference in triglyceride level between the control and those REE groups, however, a significantly lower (p < 0.01) triglyceride level was found in the 150 mg/kg REE mixture group compared with that in 75 mg/kg REE mixture group and the 150 mg/kg LaCl3.6H2O group. The results suggest that oral supplementation of REE improves growth performance in rats as in pigs. In this respect, concentration and type of REE supplemented to the diets are two important factors herein.

The antiangiogenic and therapeutic implications of endostatin

Angiogenesis plays a vital role in the pathology of cancer, ischemic diseases and chronic inflammation, among other conditions. Endostatin, a newly found protein that is distributed in some parts of the human body, has been demonstrated to have a strong inhibitory role in angiogenesis. It specifically inhibits the proliferation of endothelial cells and induces their apoptosis both in vitro and in vivo. Preclinical research has proven its effective role in the treatment of various experimental tumors in rodents. Although endostatin therapy has entered phase II clinical trials in the USA, the exact mechanism and its effects on antiangiogenesis, especially the action on the suppression of endothelial cell proliferation and induction of apoptosis, remain unclear. The treatment modality for malignancies and other angiogenesis-related diseases still requires further analysis.

Role of stroma in carcinogenesis of the prostate

Prostatic development is induced by androgens acting via mesenchymal-epithelial interactions. Androgens elicit their morphogenetic effects by acting through androgen receptors (ARs) in urogenital sinus mesenchyme (UGM), which induces prostatic epithelial development. In adulthood reciprocal homeostatic stromal-epithelial interactions maintain functional differentiation and growth-quiescence. Testosterone plus estradiol (T+E2) have been shown to induce prostatic carcinogenesis in animal models. Thus, tissue recombinant studies were undertaken to explore the mechanisms of prostatic carcinogenesis in BPH-1 cells in which ARs and estrogen receptors (ERs) are undetectable. For this purpose, BPH-1 cells were combined with UGM, and the UGM+BPH-1 recombinants were grafted to adult male hosts. Solid branched epithelial cords and ductal structures formed in untreated UGM+BPH-1 recombinants. Growth was modest, and tumors did not develop. UGM+BPH-1 recombinants treated with T+E2 formed invasive carcinomas. BPH-1 cells lack ARs and ERs, whereas rat UGM expresses both of these receptors. These data show that immortalized nontumorigenic human prostatic epithelial cells can undergo hormonal carcinogenesis in response to T+E2 stimulation via paracrine mechanisms and demonstrate that the stromal environment plays an important role in mediating hormonal carcinogenesis. During prostatic carcinogenesis the stroma undergoes progressive loss of smooth muscle with the appearance of carcinoma-associated fibroblasts (CAF). This altered stroma was tested for its ability to promote carcinogenesis of nontumorigenic but immortalized human prostatic epithelial cells (BPH-1). CAF+BPH-1 tissue recombinants formed large carcinomas. In contrast, recombinants composed of normal prostatic stroma+BPH-1 cells exhibited minimal growth. This stroma-induced malignant transformation was associated with additional genetic alterations and changes in gene expression. Thus, alteration in the stromal microenvironment was sufficient to promote malignant transformation of human prostatic epithelial cells.