Effects of heat treatment and physical processing of cottonseed on nutrient digestibility and production performance by lactating cows

Four primiparous Holstein cows were used in an experiment with a 5 x 4 Youden square design. The effects of heat processing and particle size of cottonseed used in the diets of dairy cows were investigated. Dietary treatments were control (3.6% tallow, 4.5% casein), whole cottonseed, ground cottonseed, roasted whole cottonseed, and roasted ground cottonseed. Diets consisted of 55% corn silage, 1.54% urea, and cottonseed at 18.1% or dry matter. Cottonseeds were roasted at 149 degrees C and steeped for 30 min. Roasting increased the amount of ruminally undegradable protein measured in vivo, the ratio of ruminal acetate to propionate, pH, and milk protein percentage. Ruminal digestibilities of organic matter (OM) and neutral detergent fiber and biohydrogenation of fatty acids were reduced by roasting. The grinding of cottonseed increased the total tract digestibility of OM and N and tended to increase ruminally undegradable protein of cottonseed in vivo. Interactions between heat treatment and particle size of cottonseed revealed that roasted ground cottonseed resulted in the highest total tract digestibility of OM, N, and neutral detergent fiber. Utilization of cottonseed may be improved by heat or mechanical processing as was indicated by this study.

The zebrafish BMP4 gene: sequence analysis and expression pattern during embryonic development

We have isolated zebrafish BMP4 gene from a zebrafish genomic DNA library. The size of the isolated BMP4 gene was approximately 14.9 kb. The isolated gene contained two exons which formed the complete coding region together with part of the 3'-noncoding region. The deduced BMP4 protein sequence contained 400 amino acids. Sequence comparison showed that it shared 73% amino acid sequence identity with that of human and mouse BMP4. An intron with a size of 8,963 bp was present between two coding exons. Danio retroposon A (DANA)-like retroposon was located in the intron. It contained four conserved boxes and was flanked by a pair of direct repeats of 9 nucleotide sequence (GTTTTAATA). During embryonic development of the zebrafish, a 3.8-kb BMP4 mRNA was detected from gastrula stage up to a month-old hatching larvae via Northern blot analysis. In addition, the use of reverse transcription polymerase chain reaction further demonstrated the presence of BMP4 mRNA in both the early developmental stages (i.e., cleavage and blastula) and in adult fish. Developmental expression of BMP4 protein was also analyzed. Trace amounts of an 18-kD protein were detected at pharyngula stage, while the production increased from hatching larvae to adult fish. In adult fish, the expression of BMP4 mRNA was observed in brain, heart, digestive tracts, testes, and jaw. The results suggest that the zebrafish BMP4 gene may play important roles during zebrafish development.

The signal response of IkappaB alpha is regulated by transferable N- and C-terminal domains

IkappaB alpha retains the transcription factor NF-kappaB in the cytoplasm, thus inhibiting its function. Various stimuli inactivate IkappaB alpha by triggering phosphorylation of the N-terminal residues Ser32 and Ser36. Phosphorylation of both serines is demonstrated directly by phosphopeptide mapping utilizing calpain protease, which cuts approximately 60 residues from the N terminus, and by analysis of mutants lacking one or both serine residues. Phosphorylation is followed by rapid proteolysis, and the liberated NF-kappaB translocates to the nucleus, where it activates transcription of its target genes. Transfer of the N-terminal domain of IkappaB alpha to the ankyrin domain of the related oncoprotein Bcl-3 or to the unrelated protein glutathione S-transferase confers signal-induced phosphorylation on the resulting chimeric proteins. If the C-terminal domain of IkappaB alpha is transferred as well, the resulting chimeras exhibit both signal-induced phosphorylation and rapid proteolysis. Thus, the signal response of IkappaB alpha is controlled by transferable N-terminal and C-terminal domains.

Characterization of Rab3A, Rab3B and Rab3C: different biochemical properties and intracellular localization in bovine chromaffin cells

In this study we examined the biochemical properties and subcellular localization of Rab3A, Rab3B and Rab3C in bovine adrenal chromaffin cells. The Kd for guanosine 5'-[gamma-thio]triphosphate (GTP[S]) of the three Rab3 proteins was 15, 2700 and 204 nM for Rab3A, Rab3B and Rab3C respectively. The intrinsic GTPase activity of the three Rab3 proteins seemed similar and was increased approx. 3-fold by bovine chromaffin cell lysate. Truncation of the C-terminal 31 amino acid residues decreased the binding affinity for GTP[S] of the three Rab3 proteins. When the C-terminus of Rab3C was replaced with that of Rab3A, the binding affinity of Rab3C for GTP[S] was decreased, but the replacement did not affect the affinity of Rab3B for GTP[S]. Immunostaining experiments showed that Rab3A, Rab3B and Rab3C are localized separately within chromaffin cells. Anti-Rab3A and anti-Rab3C antibodies stained vesicle-like structures, whereas anti-Rab3B antibody distinctly stained the plasma membrane. In summary, bovine chromaffin cells express the three Rab3 proteins but the subcellular localization and biochemical properties of the three Rab3 proteins are distinct.

Activation of complement and neutrophils increases vascular permeability during air embolism

Pulmonary air embolism occurs in diving and aviation during acute pressure reductions and in clinical complications. Undoubtedly physical obstructions play a role, but bubbles in blood can produce a number of indirect effects leading to tissue injury. In the present study, we investigated the involvement of the complement system and polymorphonuclear leukocytes (PMN) in altering segmental vascular resistance, lung weight gain, and filtration coefficient (Kf), by using isolated and perfused rat lungs. After establishing ventilation with air and 5% CO2, the lung was removed en bloc and suspended in a humidified chamber at 37 degrees C. Lung weight and arterial and venous pressures were monitored continuously. The buffered salt perfusate contains 4% Ficoll for osmotic balance. We used four series of perfusates containing 20% of: a) normal plasma; b) decomplemented plasma (from donor rats pretreated with a cobra venom factor); c) normal plasma and PMN at 2 x 10(6).ml-1; and d) decomplemented plasma and PMN at 2 x 10(6).ml-1. Pulmonary air embolism, air bubbles introduced through the pulmonary artery, increased pulmonary arterial resistance and pulmonary arterial blood pressure. The lung weight and lung water content were greater than those in the control groups. Air embolism increased vascular permeability, which was shown by an elevated Kf after air infusion. After air embolism, Kf was 0.63 +/- 0.05 g.min-1.cm H2O-1.100 g-1 in lungs perfused with both PMN and plasma, which was significantly greater than those in lungs perfused with either plasma (0.49 +/- 0.04), decomplemented plasma (0.44 +/- 0.03), or PMN and decomplemented plasma (0.47 +/- 0.03). These results demonstrated that air embolism increases vascular permeability of the lung by pulmonary hypertension, activation of the complement, and activation of PMN.

[An exploration of sexual knowledge, attitudes and behavior in aboriginal elementary school students in the Ping-Tung area]

The purpose of this study was to investigate sexual knowledge, attitudes and behavior of fifth and sixth grade students in aboriginal elementary schools in the Ping-Tung area. A structured questionnaire was administered to 1091 students who were selected by cluster sampling. The results showed: (1) The sexual knowledge score was low but sexual attitudes showed a positive trend. (2) 64.7% and 67.4% of students had at some time seen pictures of male or female sexual organs. (3) About 61% of students had seen sexual magazines or videotapes. (4) 66.2% of male and 88.1% of female students had heard about wet dreams or menstruation before their first experience; more than half of the students thought that wet dreams need treatment. (5) 17.8% of students had masturbation experience, and after that 59.3% of students had fear or guilt feeling. (6) Female students had significantly higher knowledge and attitude scores than male students, Demographic variables produced no significant difference in the above scores. (7) 42.4% of students most desired to know what phenomena indicate sexual maturity. (8) Sex knowledge had significantly positive correlation with sex attitude.

Gossypol arrests human benign prostatic hyperplastic cell growth at G0/G1 phase of the cell cycle

Recently we demonstrated that gossypol (GP), a male antifertility agent, is a potent inhibitor of malignant human prostate cancer cell growth that acts by arresting cells in G0/G1 phase and that this inhibitory effect may be mediated by transforming growth factor-beta 1 (TGF-beta 1). In this study we examined the effect of GP on the growth of prostatic cells from human benign prostatic hyperplasia (BPH) patients in vitro. Consistent with its inhibitory effect on the growth of malignant human prostate cancer cells, GP also acts as a potent inhibitor of cultured human BPH cell growth as assessed by thymidine incorporation assay. These results were confirmed by flow cytometric analysis which revealed that treatment of human BPH cells with increasing concentrations of GP resulted in a dose-dependent accumulation of cells in the G0/G1 phase with a concomitant decrease in cells progressing to the S and G2/M phases. Since inhibition of prostate cancer cells by GP appears to be mediated by TGF-beta 1, we also investigated the effect of GP on TGF-beta 1 gene expression in BPH cells. The results show that GP treatment resulted in a marked elevation of TGF-beta 1 gene expression indicating that TGF-beta 1 might be involved at least in part in the inhibitory pathway that is initiated by GP.

Inhibition of xanthine oxidase by synthetic cytokinin analogues

Thirteen synthetic cytokinin analogues were tested for their inhibitory effects on xanthine oxidase. The enzyme, xanthine oxidase catalyses the oxidation of hypoxanthine to xanthine and of xanthine to uric acid, which has a gamma max of 295 nm, forming the basis for a spectrophotometric assay of the activity of xanthine oxidase. The results showed that 8-azaadenine(1), 4-amino-6-hydroxypyrazolo [3,4-d] pyrimidine(4), 4-amino-6-mercaptopyrazolo [3,4-d] pyrimidine(5) and 4-aminopyrazolo [3,4-d] pyrimidine(6) display inhibitory effects on xanthine oxidase with an order of activity of IC50 = 0.54, 5.91, 8.17 and 25.46 microM, respectively. Their apparent inhibition constants (Ki) were 0.66, 1.54, 6.61 and 26.79 microM, and induced mixed(competitive-non-competitive), competitive, mixed (competitive-non-competitive), and competitive types of inhibition respectively, with respect to the substrate xanthine.

Gossypol induces spermidine/spermine N1-acetyltransferase in canine prostate epithelial cells

Gossypol is an antisteroidogenic compound naturally found in cottonseed. Gossypol has been shown to inhibit steroidogenesis in the canine prostate and may inhibit canine prostate growth. Its mechanism of action, however, is largely unknown. Our laboratory has previously demonstrated that in vivo administration of gossypol to male dogs can reduce circulating levels of testosterone and estradiol. Gossypol also showed an ability to reduce prostate weights. To search for genes regulated by gossypol in the canine prostate, differential display RT-PCR was performed on total RNAs isolated from control and gossypol-treated male dogs. Gossypol was demonstrated to induce expression of spermidine/spermine-N1-acetyl-transferase (SSAT), the major catabolic enzyme for polyamines. This induction was confirmed by Northern hybridization analysis of total RNA isolated from prostates of mature dogs treated with gossypol for 2 months. Gossypol was also shown to inhibit the progression of cells into the S phase mediated by spermidine. Our findings support the notion that gossypol can inhibit prostate cell proliferation and may be a potential therapeutic agent for use in controlling overgrowth of the prostate.

Establishment and characterization of conditionally immortalized astrocytes to study their interaction with ts1, a neuropathogenic mutant of Moloney murine leukemia virus

The cytopathic infection of primary astrocytes with ts1, a neuroimmunopathogenic mutant of Moloney murine leukemia virus (MuLV), has been correlated to intracellular accumulation of viral precursor envelope protein gPr80env. To further study this specific virus-astrocyte interaction in a homogenous population, several immortal astrocyte lines were established from neonatal FVB/N mice using the temperature-sensitive SV40 tsA58 T antigen. These cells expressed glial fibrillary acidic protein, vimentin and T antigen; appeared nontransformed; were star-shape with long processes. They were susceptible to ts1 infection and suffered a cytopathic effect similar to that caused by ts1 infection of primary astrocytes. This cytopathic effect was characterized by growth inhibition, loss of cell processes and syncytium formation. Some cells also rounded up, formed mini cells and became detached from the culture dish. As in primary astrocytes, the processing of gPr80env in the immortalized astrocytes was inefficient. Since the envelope proteins interact with the ecotropic MuLV receptor both intracellularly and on the cell surface and since the receptor has been shown to be an arginine transporter, we attempted to determine the effect of ts1 on arginine uptake by these cells. Our results showed that in both immortalized and primary astrocytes, ts1 infection reduced the uptake of arginine more than did wild-type virus infection. Since arginine localizes predominantly in astrocytes in the CNS and has diverse functions, the decrease of arginine uptake in ts1-infected astrocytes may alter the metabolism of these cells, leading to impairment of their functions.

Fibroblasts contracting collagen matrices form transient plasma membrane passages through which the cells take up fluorescein isothiocyanate-dextran and Ca2+

When fibroblasts contract collagen matrices, the cells activate a Ca(2+)-dependent cyclic AMP signaling pathway. We have found that contraction also stimulates uptake of fluorescein isothiocyanate-dextran molecules from the medium. Our results indicate that fluorescein isothiocyanate-dextran enters directly into the cell cytoplasm through 3- to 5-nm plasma membrane passages. These passages, which reseal in less than 5 s in the presence of divalent cations, also are likely sites of Ca2+ uptake during contraction and the first step in contraction-activated cyclic AMP signaling. The formation of plasma membrane passages during fibroblast contraction may reflect a general cellular response to rapid mechanical changes.

Pharmacologic modulation of pulmonary vascular permeability during air embolism

Pulmonary air embolism induces the generation of vasoactive and cytotoxic substances leading to lung injury. In the present study we investigated, in isolated and perfused rat lungs, the involvement of arachidonic acid metabolites in the alterations of vascular pressure, lung water content, and the filtration coefficient (Kf). We also tested the effects of a beta-agonist, a calcium channel blocker, and a cyclo-oxygenase inhibitor on the hemodynamic and the permeability changes following pulmonary air embolism. The artificially ventilated rat lungs were removed en bloc and suspended in a humidified chamber at 37 degrees C. The salt and buffered perfusate contained 4% Ficoll as albumin substitute for osmotic balance. We introduced air bubbles through the pulmonary artery. Air embolism increased pulmonary arterial resistance and caused pulmonary hypertension. Lungs receiving air infusion contained 88.6 +/- 0.6% water, which was significantly greater than the lung water content in the control groups (81.9 +/- 0.4%). Air embolism increased Kf by 145 +/- 19% from the baseline value. Pretreatment with indomethacin, isoproterenol, or nifedipine significantly reduced post-air-embolism lung water content to 85.8 +/- 0.5%, 84.1 +/- 0.4%, and 86.5 +/- 04%, respectively, and reduced the Kf increase to 17 +/- 8%, 1 +/- 9%, and 72 +/- 8%, respectively. These interventions did not alter the hemodynamic responses, except for the isoproterenol infusion, which shortened the half-time (T1/2) for pressure recovery after ending air infusion compared to the group with air embolism alone. Our results showed that indomethacin prevented vascular permeability increase and reduced pulmonary edema, suggesting that the cyclo-oxygenase products partially mediate the lung injury following air embolism. Furthermore, isoproterenol and nifedipine prevented or reduced the permeability increase, suggesting that alterations of the intracellular cAMP and cytosolic Ca2+ level play an important role in the pathophysiology of pulmonary air embolism.

Detection of keratinocyte growth factor (KGF) messenger ribonucleic acid and immunolocalization of KGF in the canine testis

Keratinocyte growth factor (KGF) was originally discovered in human embryonic lung fibroblasts and is a member of the fibroblast growth factor (FGF) family. Members of the FGF family have been shown to regulate testicular function. However, the recently discovered KGF has not been studied in the testis. KGF has been detected in many other tissues, including the prostate, an organ whose development and function have been associated with presence of the testis. In this study, KGF mRNA was detected in the whole testis using reverse transcription polymerase chain reaction (RT-PCR). The 575-bp KGF-specific product was detected along with a 594-bp β-actin-specific product. To identify the cell types in which KGF mRNA was predominantly expressed, interstitial cells were physically separated from seminiferous tubules. The interstitial cells were then sorted on a discontinuous Percoll gradient and total cellular mRNAs isolated. Using RT-PCR and Southern hybridization with specific cDNA probes, the KGF mRNA was detected in interstitial cells. KGF expression levels were then evaluated semiquantitatively with a competitive RT-PCR assay. KGF expression levels were highest in interstitial cells that equilibrated between 20 and 30% Percoll. Enriched Leydig cells and seminiferous tubules expressed low levels of KGF. Finally, immunohistochemical analysis was performed on canine testes using a rabbit anti-KGF polyclonal antibody. The KGF protein was localized predominantly to peritubular cells of the canine testis. These results suggest that KGF is synthesized in the canine testis.

Inhibition of xanthine oxidase by cytokinins and related substances

Fourteen cytokinins were tested for their inhibitory effects on xanthine oxidase. The enzyme, xanthine oxidase catalyses the oxidation of hypoxanthine to xanthine and of xanthine to uric acid which has lambda max of 295 nm, forming the basis for a spectrophotometric assay of the activity of xanthine oxidase. The results showed that adenine-HCl, N6-(2-isopentenyl)-adenine, purine and DL-dihydrozeatin displayed very potent activities (IC50 = 1.92, 10.99, 60.98 and 86.36 microM respectively). Their apparent inhibition constants (Ki) were 2.20, 17.99, 13.59 and 115.62 microM, and induced competitive, uncompetitive, competitive and non-competitive type inhibitions respectively with respect to the substrate xanthine.

Inhibition of human prostate cancer cells growth by gossypol is associated with stimulation of transforming growth factor-beta

Gossypol (GP), an antifertility agent in males, is also capable of inhibiting the proliferation of a wide range of cancer cells in vivo and in vitro. Thus, in this study we investigated the effect of GP on the growth of human androgen-independent prostate cancer cell line (PC3). The results showed that GP acts as a potent inhibitor of PC3 cells as determined by thymidine incorporation assay and flow cytometric analysis. Flow cytometry revealed that treatment of PC3 cells with GP resulted in a dose- and time-dependent accumulation of cells in the GO/GI phase with a concomitant decrease in cells progressing to the S and G2/M phase. These data support our thymidine incorporation results which indicated that GP is a potent inhibitor of PC3 cells. By ribonuclease protection assay, we also investigated the effect of GP on transforming growth factor-beta 1 (TGF-beta 1) gene expression in PC3 cells. Interestingly, the stimulatory effect of GP on TGF-beta 1 gene expression correlates well with its inhibitory effect on PC3 cell DNA synthesis and its ability to arrest cells in GO/G1 phase. Based on these data, it can be concluded that GP is a potent inhibitor of prostate cancer cell growth that acts by arresting cells in GO/G1 phase and that this inhibitory effect may be mediated by TGF-beta 1.

Measurement of pulmonary status and surfactant protein levels during dexamethasone treatment of neonatal respiratory distress syndrome

BACKGROUND

Early postnatal use of dexamethasone in infants with respiratory distress syndrome (RDS) has been shown effectively to improve pulmonary status and to allow early weaning off mechanical ventilation. However, the mechanisms to explain the beneficial effects of dexamethasone in ventilatory dependent preterm infants remain unclear.

METHODS

A double blind, placebo controlled study was performed to determine the change in pulmonary ventilation of premature infants with RDS as a result of dexamethasone treatment, and to evaluate the effect of dexamethasone on the levels of surfactant-associated proteins A (SP-A) and D (SP-D) in the tracheal fluid from 34 premature infants with RDS and 29 control subjects.

RESULTS

Dexamethasone treatment decreased fractional inspired oxygen concentration (FIO2), arterial carbon dioxide tension (PCO2), mean airway pressure (MAP), and facilitated successful weaning from mechanical ventilation. SP-A concentrations in the tracheal aspirates were increased at days 7 and 14, and SP-D concentrations were increased during the period from days 3 to 14 in the dexamethasone treated group compared with the control group. However, albumin levels in the tracheal aspirate samples were decreased after dexamethasone treatment over the period from days 3 to 14. There was an inverse correlation between PCO2 values and SP-A concentrations.

CONCLUSIONS

These results suggest that early use of dexamethasone can improve pulmonary status and also increase SP-A and SP-D levels in the tracheal fluid in premature infants with RDS.

Experimentally-induced prostatic hyperplasia in young beagles: a model to evaluate the chemotherapeutic effects of gossypol

This study investigated the effect of gossypol on hyperplastic canine prostates induced with long-term administration of androgen and estrogen. Twelve 16-week-old male beagle dogs were divided evenly (n = 3) into 4 treatment groups: (1) CONTROL: vehicle only; (2) Gossypol-Treated: 20 mg/kg gossypol acetic acid; (3) Steroid-Induced: 4 mg/kg testosterone and 40 micrograms/kg estradiol-17 beta; (4) Gossypol-Treated and Steroid-Induced: 4 mg/kg testosterone, 40 micrograms/kg estradiol-17 beta and 20 mg/kg gossypol. The subjects received treatments every other day for 1 month. The beagles treated with steroids developed an acute enlargement (approximately 10-fold) of the prostate as compared to control. The prostatic acini were underdeveloped and characterized by simple squamous to low cuboidal epithelium in the control subjects while acini in steroid-induced subjects were characterized by simple tall columnar epithelium. The subjects treated with gossypol had prostates histologically similar to controls with the exception of loosened periurethral connective tissue. Serum testosterone and estradiol-17 beta levels imply that gossypol can reduce steroid hormonal levels. Mean serum testosterone levels in gossypol-treated subjects were reduced approximately 50% from controls. Serum biochemistry profiles indicate that steroid and/or gossypol treatments were not toxic at the doses and duration used in this study. These observations imply that gossypol and steroid hormones can interact to alter prostate development and gossypol metabolism and/or clearance.

2-(Hydroxyalkyl)estradiols: synthesis and biological evaluation

Synthetic estrogens possessing hydroxyalkyl side chains at the C-2 position of the A-ring were designed in order to further elucidate the structural and electronic requirements of the estrogen receptor to A-ring modifications. Furthermore, these compounds were envisaged as being stable analogs of the estradiol metabolite 2-hydroxyestradiol. The homologous series of 2-(hydroxyalkyl)estradiols 1-3 has been prepared by chain extension of 2-formylestradiol 6, which, in turn, was prepared via ortholithiation of estradiol. The substituted estradiols 1-3 were assayed for their abilities to bind to the estrogen receptor in MCF-7 cells and induce estrogen-responsive gene expression. The estradiol homologs exhibited significantly weaker affinity than estradiol for the MCF-7 cell estrogen receptor, with relative binding affinities (estradiol = 100) ranging from 1.11 for 2-(hydroxymethyl)estradiol (1) to 0.073 for 2-(hydroxypropyl)estradiol (3). The relative activities for mRNA induction of the pS2 gene by the estradiol homologs closely parallel the relative binding affinities for the estrogen receptor in MCF-7 cells. 2-(Hydroxymethyl)-estradiol exhibited similar estrogen receptor affinity and pS2 gene induction to the catechol estrogen 2-hydroxyestradiol and may prove useful in examination of the further biological effects of 2-hydroxyestrogen homologs.

Three novel and one C31133T (Arg-338-->Stop) mutations of antihemophilic factor IX gene detected in Taiwan

BACKGROUND

Hemophilia-B is caused by mutation of the coagulation factor IX (F.IX) gene. The gene is about 34 kilobases in length and contains 8 exons ranging from 25 to 548 base pairs. There is no common mutation pattern of this gene in any population as there is in thalassemia. The hope is to localize the mutations in patients for use in making rapid familial surveys and for prenatal diagnoses.

METHODS

Diagnoses for a male patient with a newly-discovered mutation in Taiwan and three others with different novel mutations of F.IX gene were made from the results of prothrombin time (PT), activated partial thromboplastin time (APTT), assay of coagulation factors activity and factor IX antigen (F.IX:Ag) and also by assay of its inhibitor. The polymerase-chain-reaction (PCR)-based direct sequencing method was applied to evaluate all of the 8 exons and their flanking regions of F.IX gene for these patients.

RESULTS

The four male patients are all severe hemophilia-B. In the three patients with novel mutation of F.IX gene, two have a very low F.IX:Ag of less than 1% and one has 73%, but no one has any inhibitor. One of the four mutations is A to C transversion at nucleotide (nt) 10458 resulting in tyrosine (69) to serine change in epidermal growth factor (EGF) type B domain. Although the F.IX:Ag is present, the F.IX activity (F.IX:C) is markedly deficit owing to the change of beta-hydroxylase recognition site. Another two have mutations at the splicing junctions. They are G to C transversion at nt 118, i.e. the first base of IVS-1 splicing donor, and G to T transversion at nt 17668, the last base of IVS-4 splicing recipient. These mutations may cause splicing failure and subsequently result in deficiency of both F.IX activity and antigen. The other mutation that has never previously presented in this country is a C to T transition (arginine-338 to stop) at nt 31133 that results in early termination of translation.

CONCLUSIONS

The G to C mutation at nt 118 creates an Alu I restriction site and the C to T mutation at nt 31133 abolishes a Taq I site. Therefore, familial survey and rapid prenatal diagnosis for these patients by PCR-based direct sequencing method or by the restriction of enzyme cutting method pointing at the known mutation sites are certainly possible to achieve in our patients.

Keratinocyte growth factor (KGF/FGF-7) has a paracrine role in canine prostate: molecular cloning of mRNA encoding canine KGF

cDNA encoding the canine keratinocyte growth factor (KGF) was cloned from normal canine prostate tissue. The authentic canine KGF cDNA sequence, 686 bp in length, spans the protein-coding region and 88 bp of the 5' and 19 bp of the 3' untranslated regions of canine KGF. The predicted amino acid sequence of canine KGF is composed of 194 amino acid residues. Canine KGF exhibits highest homology with the human KGF cDNA and amino acid sequences (95.8% and 97.4%, respectively), while it demonstrates the lowest homology with the rat sequences at 88.0% and 92.3%, respectively. The degrees of homology with mouse cDNA and amino acid sequences are 91.8% and 95.9%, respectively. By using RNase protection assay, KGF was shown to be expressed in normal prostate tissues of both mature and young (5-month-old) dogs. In vitro, the recombinant canine KGF has mitogenic activity on cultured canine epithelial cells, whereas it has no effect on cultured canine prostatic stromal cells. This novel canine KGF cDNA may be a valuable tool in the study of human benign prostatic hyperplasia using the canine prostatic as a model.

Gossypol inhibits human chorionic gonadotropin-stimulated testosterone production by cultured canine testicular interstitial cells

Gossypol (GP) is a natural polyphenolic compound that possesses antifertility and antisteroidogenic activities in both males and females. The dog is highly sensitive to GP toxicity, yet GP's effect on canine testicular steroidogenesis has never been reported. Thus, the present study examines GP's effects on human chorionic gonadotropin (hCG)-induced testosterone (T) production by primary cultured canine testicular interstitial cells. After decapsulation and enzymatic dissociation of canine testes in Dulbecco's Modified Eagle Medium with Ham's Nutrient Mixture F-12 (1:1; DME/F-12) containing 0.1% collagenase, 0.1% BSA, and 10 micrograms/ml DNase 1 (37 degrees C, 20 min), interstitial cells were isolated by sedimentation and filtration (140 microns) and then cultured in supplemented DME/F-12 medium (5 micrograms/ml insulin, 5 micrograms/ml transferrin, 5 ng/ml sodium selenite; DME/F-12/S) containing 0.1% fetal bovine serum (FBS). FBS was used to enhance cell attachment during the first 24 hours of culture. After 24 hours, the medium was replaced with serum-free DME/F-12/S and the cells were cultured for an additional 24 hours. Thereafter, cells were treated with hCG (0.1 IU/ml) alone and in combination with GP (0.05, 0.5, 2.5 and 5.0 microM). Media were collected for T radioimmunoassay and cells for protein estimation after 8, 16 and 24 hours of treatment. Treatment with hCG significantly (p < 0.05) stimulated T production over that of controls at all treatment times examined. At 8, 16 and 24 hours, T secretion was elevated from 0.91 +/- 0.25, 1.32 +/- 0.42, and 1.41 +/- 0.40 pg/microgram protein to 2.36 +/- 0.50, 2.84 +/- 0.60, and 2.82 +/- 0.43 pg/microgram protein, respectively. At 0.5, 2.5 and 5.0 microM, GP significantly (p < 0.05) reduced hCG-induced T secretion at 16 and 24 hours of treatment to 1.79 +/- 0.50, 1.62 +/- 0.12, 1.34 +/- 0.16 (16 hr), and 1.53 +/- 0.38, 1.43 +/- 0.11, 1.42 +/- 0.32 (24 hr) pg/microgram protein, respectively. At 8 hours, T production was reduced by 2.5 and 5.0 microM GP to 1.08 +/- 0.55 and 0.93 +/- 0.61 pg/microgram protein, respectively. GP, however, did not reduce T production to below basal levels. These results demonstrate the inhibition of hCG-induced T production by GP in cultured canine testicular interstitial cells.

Long-term cultivation and productive infection of primary thymocyte cultures by a thymocytopathic murine retrovirus

ts1, a mutant of MoMuLV, selectively kills T cells and neurons in the infected host resulting in neuroimmunodegeneration. In the infected thymus there is an early increase in mitosis of thymocytes followed by rapid death, suggesting that thymocyte death may be induced by viral mitogenic activation. Studies on thymocytes obtained from ts1-infected mice indicated that the ts1-induced depletion of thymocytes is mediated through activation-induced death by apoptosis. To further investigate the interaction between ts1 and thymocytes, we have established long-term primary murine thymocyte cultures by placing the thymocytes together with thymic remnants in culture medium containing IL-2 and IL-7. These thymocytes retained their immature phenotype and we susceptible to infection by ts1 and its parental wild-type MoMuLV. ts1-infected thymocytes proliferated initially at accelerated rate but subsequently produced more infectious virus and died much faster than control or MoMuLV-infected thymocytes. These in vitro studies to some extent reflect our in vivo studies reported previously.