Interaction of the adenovirus 14.7-kDa protein with FLICE inhibits Fas ligand-induced apoptosis

Adenovirus type 5 encodes a 14.7-kDa protein that protects infected cells from tumor necrosis factor-induced cytolysis by an unknown mechanism. In this report, we demonstrate that infection of cells with an adenovirus vector expressing Fas ligand induced rapid apoptosis that was blocked by coinfection with a virus expressing 14. 7K. Moreover, AdFasL/G infection resulted in the rapid activation of DEVD-specific caspases, and caspase activation was blocked by coinfection with Ad14.7/G. Cell death induced by the overexpression of Fas ligand, Fas-associated death domain-containing protein (FADD)/MORT1, or FADD-like interleukin-1beta-converting enzyme (FLICE)/caspase-8 in a virus-free system was efficiently blocked by 14.7K expression. Moreover, we demonstrate that 14.7K interacts with FLICE. These results support the idea that FLICE is a cellular target for the 14.7-kDa protein.

Detection of p53 point mutations by single strand conformation polymorphism: analysis by capillary electrophoresis

We have analyzed five p53 single point mutations by single strand conformation polymorphism using capillary electrophoresis (CE-SSCP) and have compared these measurements to measurements obtained by slab gel electrophoresis (SG-SSCP). PCR primers were used for amplification of specific exons for mutation detection. 5' Primers were labeled with FAM (5-carboxyfluorescein) and 3' primers were labeled with JOE (2',7'-dimethoxy-4',5'-dichloro-6-carboxyfluorescein). CE-SSCP was performed using the Perkin Elmer ABI PRISM 310 Genetic Analyzer with GeneScan Software and the Beckman P/ACE 5510 CE equipped for laser-induced fluorescence detection. Although the shifts in migration times for the p53 mutations relative to the corresponding wild-type strands could be successfully detected by either SG or CE analysis, the individual electrophoresis run times were about tenfold faster and more automated with capillary electrophoresis. The CE-SSCP measurements were performed at temperatures ranging from 10 to 60 degrees C on a prototype instrument. For mutations measured at ambient temperature (25 degrees C), characteristic shifts in direction and magnitude were observed in the migration times of both strands of all mutations relative to the wild type. This demonstrated the ability of CE at ambient temperature to resolve these mutations. However, the magnitude and direction of shifts in migration time varied with temperature in a discrete pattern for each mutation and resulted in a temperature-specific profile for each mutation. This demonstrated that extended temperature control will be an important advantage in resolving single point mutations by CE-SSCP. In addition, by using CE, discrete intra-strand isoforms could be easily observed at different temperatures. The combination of mutation-specific temperature profiling and analysis of isoforms by CE-SSCP should be of help to the diagnostic community in the detection of genetic mutations.

Development of standard reference materials for diagnosis of p53 mutations: analysis by slab gel single strand conformation polymorphism

We have amplified by polymerase chain reaction (PCR) a 2.0 kbp region of the p53 gene containing exons 5--9 from seven cell lines reported in the literature to contain the majority of mutations reported for this gene. Sequence analysis of these products show that all seven cell lines contain mutations within the mutational hot spots of the p53 gene. Six of the seven clones have single base substitutions and the seventh has a single base deletion. We have analyzed the seven p53 single point mutations by single strand conformation polymorphism (SSCP) analysis using fluorescence slab gel electrophoresis (SG-SSCP). Fluorescent-labeled PCR primers were used for amplification of specific exons for mutation detection. SG-SSCP was conducted using Model 373 and Model 377 DNA sequencers with GeneScan Software (Perkin Elmer, Applied Biosystem Division). Nine different gel systems were first tested for their ability to resolve the p53 mutations using the Model 373 instrument. Two gel systems were capable of resolving all of the mutations that were screened. Optimal results were obtained with 12% w/v acrylamide 50:1 plus 10% v/v glycerol. This gel system was used to evaluate the effect of temperature on the ability to resolve the mutations. The separation with respect to wild type varied for each mutation examined. Subambient temperature (20 degrees C) was preferable overall for discrimination of these mutations as a group. We intend to use this system to examine a much larger panel of p53 mutation standards that are now under development.

Insulin selectively primes Th2 responses and induces regulatory tolerance to insulin in pre-diabetic mice

Little is known about the immunological impact of insulin administration other than it can boost insulin autoantibody levels. In particular, while the subcutaneous administration of a soluble foreign antigen (without adjuvant) is generally only weakly immunogenic in a naive animal, it is unknown what effect the subcutaneous administration of a soluble self-antigen has in animals with established autoimmune responses to the antigen. Addressing these questions in pre-diabetic nonobese diabetic (NOD) mice, we examined the effects of administering insulin, as well as the metabolically inactive B-chain of insulin, on insulin-specific cellular and humoral immune responses. We show that pre-diabetic NOD mice have a spontaneous Th1-biased response against insulin. Administering insulin, or the insulin B-chain, rather than boosting the established Th1 response, primed Th2 cellular and humoral immunity to insulin, shifting the predominant insulin response toward a Th2 phenotype. Despite the presence of a Th1 response against insulin, insulin treated mice failed to mount proliferative T-cell responses following immunization and challenge with insulin, demonstrating that the treatment induced an active form of tolerance to this autoantigen. Thus, the subcutaneous administration of a soluble antigen can engage Th2 responses and induce self-tolerance, even after the establishment of autoreactive Th-1 responses. Such immune deviation and induced regulatory tolerance may contribute to the protective effects of prophylactic insulin therapy, as well as the establishment of a "honeymoon" phase in new-onset insulin-dependent diabetic patients.

An experimental study on rat model of parkinsonism by gene therapy

OBJECTIVE

To induce significant improvement of motor abnormalities and striatal dopamine (DA) levels in rat model of Parkinson's disease (PD), by intracerebral grafting of the genetically modified muscle cells expressing tyrosine hydroxylase (TH).

METHODS

Primary myoblasts and myotubes from the rat were prepared by cell culture and a plasmid, pCMVTH, containing TH gene and a promoter of cytomegalovirus (CMV) was constructed by DNA recombination technique. The primary muscle cells were transfected with newly constructed pCMVTH DNA vector, by using lipofection. These genetically modified muscle cells were grafted into the caudate- putamen of 6-OHDA-lesioned rats, representing PD models. Before and after grafting, the rotational behaviour and the striatal levels of DA and its metabolities were tested at different postoperative survival times. In addition, the immunocytochemistry for showing TH activity was done both in vitro and in vivo.

RESULTS

The newly constrcuted plasmid, pCMVTH was proved to contain TH gene and have correct direction of insertion. The cultured primary myoblasts and myotubes lipofected with pCMVTH were immunocytochemically shown to express TH activity in vitro. After grafting, these TH-expressing muscle cells showed to have a long-term survival cells in vivo and induced a marked decrease in abnormal locomotion and a increase in striatal DA levels for PD rat model.

CONCLUSIONS

In experimental gene therapy for PD, the pCMVTH is a useful vector for carrying TH gene. The lipofection is a practical technique for transferring a target gene into eukaryotes and primary cultured muscle cells should be a good vehicle for DNA transfer and intracerebral grafting.

Beneficial effects of early coronary reperfusion on left ventricular remodeling and systolic function in patients with acute myocardial infarction

OBJECTIVE

To evaluate the beneficial effects of early coronary reperfusion on left ventricular remodeling (LVRM) and systolic function in patients with acute myocardial infarction (AMI).

METHODS

Eighty-one patients with first AMI in the convalescent stage and having undergone left ventriculography (LVG) and coronary arteriography (CAG) were divided into four groups: the anterolateral wall (ALW) myocardial infarction (MI) non-reperfusion (n = 20) and reperfusion (n = 21), and inferoposterial wall (IPW) MI non-reperfusion (n = 20) and reperfusion (n = 20), according to infarct location and early treatment with or without successful coronary reperfusion therapy within 6 hours after onset of symptoms. By LVG, the parameters of LVRM and systolic function in the four MI groups were analyzed and compared with those in normal group (n = 25) and between the two reperfusion and non-reperfusion MI groups.

RESULTS

In both ALW and IPW MI non-reperfusion groups, the left ventricular (LV) end-diastolic volume (EDV), circumference (EDC), short-axis dimension (EDD), short to long axis ratio (ED-D/L), sphericity index (ED-SI) and end-systolic volume (ESV) were all significantly increased (P < 0.01-0.001), while LV ejection fractions (LVEF) were significantly decreased (both P < 0.001) when compared with those of normal group; and the increase in ESV and decrease in LVEF were both significantly greater in ALW than in IPW MI groups (both P < 0.01). In both ALW and IPW MI reperfusion groups, however, the EDV, EDD, ESV, as well as the extent and severity of regional wall motion abnormality (RW-MA) were significantly smaller (P < 0.05-0.001), while LVEF were significantly higher (P < 0.01-0.001) when compared with those in the two non-reperfusion MI groups respectively. There were no longer significant differences in LVEF and ESV between ALW and IPW MI groups (both P > 0.05). The EDC in IPW MI reperfusion group and the ED-D/L and ED-SI in ALW MI reperfusion group were also significantly reduced compared with those in the two non-reperfusion MI groups respectively (P < 0.05-0.001). All the above parameters in the two reperfusion MI group were decreased to the normal in comparison with normal group except ESV and LVEF, and ED-D/L and ED-SI in IPW MI group.

CONCLUSION

It was indicated that in both ALW and IPW MI non-reperfusion groups, LVRM had occurred in convalescent stage of AMI with an increase in EDV and EDC, spherical change in LV shape, and accompanying reduction in LV systolic function; and early coronary reperfusion in AMI could reduce the extent and severity of RWMA, prevent from LV enlargement and remodeling, and preserve or improve LV systolic function with more prominence in ALW MI.

A new class of biorthogonal wavelet systems for image transform coding

We construct general biorthogonal Coifman wavelet systems, a new class of compactly supported biorthogonal wavelet systems with vanishing moments equally distributed for a scaling function and wavelet pair. A time-domain design method is employed and closed-form expressions for the impulse responses and the frequency responses of the corresponding dual filters are derived. The resulting filter coefficients are all dyadic fractions, which is an attractive feature in the realization of multiplication-free discrete wavelet transform. Even-ordered systems in this family are symmetric, which correspond to linear-phase dual filters. In particular, three filterbanks (FBs) in this family are systematically verified to have competitive compression potential to the 9-7 tap biorthogonal wavelet FB by Cohen et al., which is currently the most widely used one in the field of wavelet transform coding. In addition, the proposed FB's have much smaller computational complexity in terms of floating-point operations required in transformation, and therefore indicate a better tradeoff between compression performance and computational complexity.

Determinant spreading of T helper cell 2 (Th2) responses to pancreatic islet autoantigens

The nature (Th1 versus Th2) and dynamics of the autoimmune response during the development of insulin-dependent diabetes mellitus (IDDM) and after immunotherapy are unclear. Here, we show in nonobese diabetic (NOD) mice that the autoreactive T cell response starts and spreads as a pure Th1 type autoimmunity, suggesting that a spontaneous Th1 cascade underlies disease progression. Surprisingly, induction of antiinflammatory Th2 responses to a single beta cell antigen (betaCA) resulted in the spreading of Th2 cellular and humoral immunity to unrelated betaCAs in an infectious manner and protection from IDDM. The data suggest that both Th1 and Th2 autoimmunity evolve in amplificatory cascades by generating site-specific, but not antigen-specific, positive feedback circuits. Determinant spreading of Th2 responses may be a fundamental mechanism underlying antigen-based immunotherapeutics, explaining observations of infectious tolerance and providing a new theoretical framework for therapeutic intervention.

Effect of SR-140333, a neurokinin-1 receptor antagonist, on airway reactivity to methacholine in sedated rats

AIM

To study the roles of neurokinins in the airway reactivity (AR) to methacholine chloride (MC).

METHODS

The effects of (S)-1-(2-[3, 4-dichlorophenyl)-1-(3-isopropoxyphenylacetyl) piperidin-3-yl]ethyl)-4-phenyl-1-azoniabicyclo [2.2.2]octane.chloride (SR-140333), a neurokinin-1 receptor antagonist, on AR to inhaled MC in diazepam-sedated rats, and on MC-induced contraction of isolated tracheal spiral strips were observed.

RESULTS

SR-140333 inhibited the increase in respiratory rate (RR) induced by MC aerosol (10-1000 mumol/m3), and the ID50 for inhibiting the response to MC aerosol (1 mmol/m3) was 4.9 micrograms.kg-1 (95% confidence limits 1.4-17.2 micrograms.kg-1). SR-140333 1 mumol.L-1 had no inhibitory effect on MC-induced tracheal contraction. Atropine blocked responses to MC both in vivo and in vitro.

CONCLUSION

Endogenous neurokinins are involved in the AR to MC in rats, at least partly mediated via neurokinin-1 receptors.

Targetting of the gene encoding fibrillin-1 recapitulates the vascular aspect of Marfan syndrome

Aortic aneurysm and dissection account for about 2% of all deaths in industrialized countries; they are also components of several genetic diseases, including Marfan syndrome (MFS). The vascular phenotype of MFS results from mutations in fibrillin-1 (FBN1), the major constituent of extracellular microfibrils. Microfibrils, either associated with or devoid of elastin, give rise to a variety of extracellular networks in elastic and non-elastic tissues. It is believed that microfibrils regulate elastic fibre formation by guiding tropo-elastin deposition during embryogenesis and early post-natal life. Hence, vascular disease in MFS is thought to result when FBN1 mutations preclude elastic fibre maturation by disrupting microfibrillar assembly. Here we report a gene-targetting experiment in mice that indicates that fibrillin-1 microfibrils are predominantly engaged in tissue homeostasis rather than elastic matrix assembly. This finding, in turn, suggests that aortic dilation is due primarily to the failure by the microfibrillar array of the adventitia to sustain physiological haemodynamic stress, and that disruption of the elastic network of the media is a secondary event.

Xenopus Cdc6 confers sperm binding competence to oocytes without inducing their maturation

Amphibian eggs normally require meiotic maturation to be competent for fertilization. A necessary prerequisite for this event is sperm binding, and we show that under normal physiological conditions this property is acquired at, but not before, meiotic maturation. Immature oocytes do not bind sperm, but injection of total egg poly(A)+ mRNA into immature oocytes confers sperm binding in the absence of meiotic maturation. Using an expression cloning approach we have isolated a single cDNA from egg poly(A)+ mRNA that can induce sperm binding in immature oocytes. The cDNA was found to encode Xenopus Cdc6, a protein that previously has been shown to function in initiation of DNA replication and cell cycle control. This unanticipated finding provides evidence of a link between a regulator of the cell cycle and alterations in cell surface properties that affect gamete binding.

A clinical study on compound da huang (radix et Rhizoma rhei) preparations for improvement of senile persons' memory ability

By comparison of the effects of the Compound Tong Jiang Oral Liquid with Da Huang added (TJ [symbol: see text]) and Qi Yin Oral Liquid (QY [symbol: see text]) without Da Huang on senile persons' memory ability, it is discovered that the effects of TJ on shortening the interval between defecations and the duration of defecation, and on improving senile persons' memory ability are significantly better than that of QY (P < 0.05). In addition, TJ can also decrease the serum content of lipid peroxidase and increase the superoxide dismutase activity in red blood cells (RBC). Thus, it is demonstrated that Dahuang and its agents possess the action of anti-senility and can improve mentality.

[Preliminary studies on proliferation of hemorrhagic fever with renal syndrome virus in Leptotrombidium (L.) Scutellare]

In order to observe further the proliferation and kinetic changes of hemorrhagic fever with renal syndrome virus (HFRSV) in Leptotrombidium (L.) Scutellare infected with HFRSV, the raised Leptotrombidium (L.) Scutellare which were at larve stage or at nymph stage were grinded and sterilized by filtration at interval of 20 days, each batch of the filtrate was inoculated separately to Vero-E6 cells and the titre (TCID50/ml) of HFRSV was measured. The results confirmed: HFRSV were isolated from each batch of larve besides the batch at the 60th days, and the titre of HFRSV was -10(-1)-10(-4); HFRSV were also isolated from two batches of nymph. The isolated HFRSV were amplified by PCR technique and the HFRSV RNA were positive. The above results give rise to evidence that Leptotrombidium (L.) Scutellare might be the transmission vector of HFRSV.

A Pentium personal computer-based craniofacial three-dimensional imaging and analysis system

Personal computer (PC)-based computing is now ubiquitous in common consumer applications. Although PCs have equaled or surpassed engineering workstations in basic computing power and economy, there is still strong workstation dependency for imaging applications. This article demonstrates that a complete system, based on a Pentium PC (Intel Corporation, Santa Clara, CA) and readily available and inexpensive software, can be built very economically for effective execution of most of the commonly used three-dimensional imaging operations. For the craniofacial application, the Pentium system offers a twofold speed advantage over a Sparc 20 system using similar three-dimensional processing software. The Pentium system allows interactive fuzzy volume rendering, and manipulation and analysis of complex hard and soft-tissue structures.

[Effect of SR-140333, a tachykinin NK-1 antagonist, on antigen-induced airway hyperresponsiveness in sensitized rats]

In the present study, the effects of SR-140333, ((S)-1-(2-[3,4-dichlorophenyl)-1-(3-isopropoxyphenylacetyl)piperidin- 3yl]ethyl)-4-phenyl-1-azoniabicyclo[2.2.2]octane.chloride), a nonpeptide antagonist for tachykinin NK-1 receptor, on the antigen-induced airway response to methacholine (MCh) aerosol and airway inflammation in sensitized SD rats were investigated. The baseline respiratory frequencies, tachypnea response to methacholine(MCh), the -log PC30 values of MCh and the leukocyte counts in bronchoalveolar lavage significantly increased after inhalation of 1% oval albumin(OA) aerosol. SR-140333 (152 nmol.kg-1, i.p.) or dexamethasone(368 nmol.kg-1, i.p.), bid x 3 d inhibited these responses. SR-140333 at a low dose of 0.01 mg.kg-1 showed an incomplete inhibition. From these results, we conclude that antigen challenge causes airway hyperresponsiveness and airway inflammation and that tachykinin NK-1 receptor antagonist inhibits these responses.

[A new non-invasive method for measurement of airway responsiveness in sedated rats]

Sprague-Dawley rats sedated with intraperitoneal injection of diazepam (7.5 mg/kg) were placed in a plethysmograph to measure the changes in spontaneous respiration. Inhalation of methacholine (MCh) or acetylcholine (ACh) aerosol did not alter the volume of breathing, but increased respiratory frequency (RF) to the same extent in a concentration-dependent manner. On the other hand, the tachypnea effect of MCh lasted 11 min, and that of ACh only 3 min. Urethane anesthesia inhibited spontaneous respiration and the response to MCh. Atropine, salbutamol and aminophylline inhibited MCh-induced tachypnea. In sensitized rats, the response to MCh was potentiated 6 h after inhalation of ovalbumin aerosol. The results indicate that sedation with diazepam and inhalation of MCh aerosol used in this report are suitable for measuring airway responsiveness in terms of degree of increase of respiratory frequency.

[Effects of yizhi pills on memory, superoxide dismutase and malondialdehyde of brain and immunity in mice]

Passive avoidance tests have shown that Yizhi Pills (YZ) markedly improve the memory of normal mice at a dose of 100 mg/kg after oral administration for fifteen days, and significantly reverse the scopolamine, NaNO2 and EtOH-induced disruptions of memory retention in mice at doses of 100, 200, 500 mg/kg after oral administration for five days. In aged mice induced by D-galactose, YZ also significantly improve the impaired memory, increase the activity of SOD and decrease the content of MDA in brain. All these effects were observed at doses of 200, 500 mg/kg after oral administration for forty-one days. YZ significantly promote blood carbon particle clearance, enhance hemolysin antibody in immunodepressed mice induced by cyclophosphamide, and increase earswelling in immunodepressed mice induced by prednisolonum.

Xenopus laevis sperm-egg adhesion is regulated by modifications in the sperm receptor and the egg vitelline envelope

The biochemical and ultrastructural changes in the envelope of the Xenopus laevis egg that occur during oviposition and fertilization have been thoroughly studied (Hedrick, J. L., and Nishihara, D. M., Methods Cell Biol. 36, 231-247, 1991; Larabell, C. A., and Chandler, D. E., J. Electron Microsc. Tech. 17, 294-318, 1991). However, the biological significance of these changes with respect to gamete interaction has been unclear. In the current study, it was found that changes in the envelope are directly responsible for regulating sperm-egg adhesion, an initial step of fertilization. As a result of these transformations, sperm bind only to unfertilized oviposited eggs, not to oocytes or coelomic eggs. In addition, they do not bind to fertilized eggs. The molecular and cellular basis of the regulation of the sperm binding process was investigated in the context of our recent findings that two structurally related envelope glycoproteins, gp69/64, serve as sperm receptors during fertilization (Tian, J.-D., Gong, H., Thomsen, G. H., and Lennarz, W. J., J. Cell Biol. 136, 1099-1108, 1997). Although the purified gp69/64 glycoproteins isolated from the oocyte or coelomic egg envelopes exhibited sperm binding activity, when these proteins are part of the intact oocyte or coelomic egg envelopes, they are not accessible to either anti-gp69/64 antibodies or to sperm. During the conversion from the coelomic to the vitelline envelope, the gp69/64 sperm receptors become exposed on the surface, an event that correlates with proteolytic cleavage of gp43 and accompanying ultrastructural alterations in the envelope. Conversely, after fertilization, when the vitelline envelope of the egg is converted to the fertilization envelope of the zygote, limited proteolytic cleavage of the sperm receptor results in loss of sperm binding activity. In addition, formation of a fertilization layer on top of the structurally altered VE adds another physical block to sperm binding. These results provide new insights into structure-function relationships between envelope components of the anuran egg, and provide further evidence supporting the key role of gp69/64 as sperm receptors during X. laevis fertilization.

Latency estimation of auditory brainstem response by neural networks

In the clinical application of auditory brainstem responses (ABRs), the latencies of five to seven main peaks are extremely important parameters for diagnosis. In practice, the latencies have mainly been done by manual measurement so far. In recent years, some new techniques have been developed involving automatic computer recognition. Computer recognition is difficult, however, since some peaks are complicated and vary a lot individually. In this paper, we introduce an artificial neural network method for ABR research. The detection of ABR is performed by using artificial neural networks. A proper bandpass filter is designed for peak extraction. Moreover, a new approach to estimate the latencies of the peaks by artificial neural networks is presented. The neural networks are studied in relation to the selection of model, number of layers and number of neurons in each hidden layer. Experimental results are described showing that artificial neural networks are a promising method in the study of ABR.

[Effects of exposure to hypoxia on the skin temperature and glycogen content of frostbitten feet in rabbits]

Effect of exposure to acute hypoxia and hypoxia for 2 weeks on the skin temperature and content of glycogen of frostbitten feet in rabbits were observed. The results showed that the skin temperatures and content of glycogen were decreased in frostbite at normoxia (FN) group frostbite during acute hypoxia (FAH) group and frostbite hypoxia for 2 weeks (FH-2w) group. After treatment with warm chlorhexidine immersion the skin temperature and glycogen content in treated feet of FN and FAH group were increased, as compared with untreated feet. However, there was no difference between treated and untreated feet in FH-2w group, suggesting that there may be severe disturbance of blood circulation on frostbitten feet under this condition.

[The relationship between histologic grading of malignancy and regional lymph node metastasis in squamous cell carcinoma of larynx]

Forty cases of squamous cell carcinoma of larynx have been studied by using five factors scale in order to investigate the relation between histologic grading of malignancy and regional lymph node metastasis. The results show that high degree malignancy tumor (which gets more than ten points) and diffusly invased tumor have a significantly higher proportion of regional lymph node metastasis than others. There was no relation between histologic grading of malignancy and T categories. It indicated that histologic grading of malignancy may be a good help in predicting patient evolution.

Gamete interactions in Xenopus laevis: identification of sperm binding glycoproteins in the egg vitelline envelope

A quantitative assay was developed to study the interaction of Xenopus laevis sperm and eggs. Using this assay it was found that sperm bound in approximately equal numbers to the surface of both hemispheres of the unfertilized egg, but not to the surface of the fertilized egg. To understand the molecular basis of sperm binding to the egg vitelline envelope (VE), a competition assay was used and it was found that solubilized total VE proteins inhibited sperm-egg binding in a concentration-dependent manner. Individual VE proteins were then isolated and tested for their ability to inhibit sperm binding. Of the seven proteins in the VE, two related glycoproteins, gp69 and gp64, inhibited sperm-egg binding. Polyclonal antibody was prepared that specifically recognized gp69 and gp64. This gp69/64 specific antibody bound to the VE surface and blocked sperm binding, as well as fertilization. Moreover, agarose beads coated with gp69/64 showed high sperm binding activity, while beads coated with other VE proteins bound few sperm. Treatment of unfertilized eggs with crude collagenase resulted in proteolytic modification of only the gp69/64 components of the VE, and this modification abolished sperm-egg binding. Small glycopeptides generated by Pronase digestion of gp69/64 also inhibited sperm-egg binding and this inhibition was abolished by treatment of the glycopeptides with periodate. Based on these observations, we conclude that the gp69/64 glycoproteins in the egg vitelline envelope mediate sperm-egg binding, an initial step in Xenopus fertilization, and that the oligosaccharide chains of these glycoproteins may play a critical role in this process.

Pax-5 is identical to EBB-1/KLP and binds to the VpreB and lambda5 promoters as well as the KI and KII sites upstream of the Jkappa genes

During B cell differentiation, the pre-B cell stage plays a significant role in immunoglobulin gene rearrangement in the context of the allelic exclusion and kappa chain gene rearrangement. We previously reported that the early B cell-specific binding protein (EBB)-1 transcription factor binds to the promoters of two pre-B cell-specific genes, VpreB and lambda5, and regulates their pre-B cell-specific expression. Here, we demonstrate that EBB-1 binds to the KI and KII sites in the upstream of Jkappa region, which are crucial for kappa chain gene rearrangement. Gene transfer and gel-shift assays demonstrate that EBB-1 is identical to Pax-5 and binds to promoters of VpreB and lambda5 as well as the KI and KII sites. Our results suggest that Pax-5 plays an important role in the coordinate regulation of several immunoglobulin gene family members that are crucial in B cell development.

[Development of a SIRI-TOFMS and the application research progress]

The only one set of Sputter Initiated Resonance Ionization-Time of Flight Mass Spectrometer (SIRI-TOFMS) in China was designed and developed. A liquid gallium ion source with micron level diameter of beam, frame-style piezoeletric ceramic sub-micron sample manipulator, a secondary electron imaging system and a computer controlled precise targeting system as well as a real colour big screen image displaying system were added so as to improve its microanalysis capability. By means of this apparatus, trace analysis of Au in minerals and Cu in standard steel samples were carried out. The detection limit of them is 40ng/ and microg/g level, respectively. Aside from the above detections, other preliminary researches ere also performed.

A whole genome shotgun gene fusion method for isolation of translation initiation sites in Escherichia coli: identification of Haemophilus influenzae translation initiation sites in E. coli

We have developed a new method for isolating translation initiation sites based on the expression of Haemophilus influenzae Rd gene fusions with the Escherichia coli galactokinase (galK) gene. We cloned random DNA fragments of H. influenzae Rd DNA into a plasmid vector containing the galK coding sequence from which the translation initiation site (the ribosome binding site and translation initiation codon) had been removed. A subset of the cloned DNA fragments contained translation initiation sites that, when fused to the galK gene, produced active galactokinase and complemented the host galK mutation. Molecules expressing galactokinase activity were isolated and characterized by DNA sequence analysis, and the sequences were aligned with the recently completed whole genomic sequence of H. influenzae Rd. Translation initiation sites for known, hypothetical, and new genes were identified. Translation initiation sites internal to the coding sequences of a number of genes were identified, suggesting that internal translation initiation sites are common, especially in large genes. This shotgun method provides functional information on translation initiation sites and helps to define gene coding sequences.

[Intracerebral grafting of ex vivo transgene muscle cells in rat model of parkinsonism]

The rat model with a unilateral 6-OHDA-induced lesion of the dopaminergic system was used for experimental study on gene therapy for Parkinson's disease (PD). The plasmid pCMVTH (6.04 kb) was constructed as a vector containing the gene of tyrosine hydroxylase (TH) and transferred into cultured primary muscle cells by lipofection ex vivo. After expression of TH was determined in vitro, the intracerebral grafting (ICG) of these genetically modified cells was made in the striatum of PD rat model. The results showed that TH-expressing muscle cells had a long-term survival in the brain and induced a marked decrease in abnormal locomotion and increase in striatal dopamine levels for rat model.

[The determination of vitamin D in fortified milk and other foods by high performance liquid chromatography (HPLC)]

An HPLC procedure for determination of vitamin D(VD) in fortified milk and food has been developed. The samples were saponified by adding KOH, ethanol and vitamin C at 75 degrees C for 30 min. The digest was extracted with hexane in multistep manner. The extract was washed with 5% KOH, distilled water and 55% ethanol, and evaporated under reduced pressure at 50 degrees C. The residue was dissolved in hexane, transferred to a coentrifuge tube, evaporated under N2 and then dissolved in 200 microL mobile phase. The latter was injected into a silica column (10 microm, 30 cm x 4 mm) for cleanup, eluted with mixture of cyclohexane-hexane containing 0.8% isopropanol and detected at UV 254nm. VD fraction was collected according to the retention time of standard, evaporized under N2, redissolved in 100 microL MeOH, and separated on a C18 column (10 microm, 30 cm x 4 mm) with MeOH/H2O (98:2) as eluent. VD2 and VD3 were eluted as a mixture under the conditions. Recoveries of the method were 94.8% to 99.7%. The average CV (n = 5) for within and between day measurements were 1.6% and 2.1% respectively. This method was already used to determine the content of vitamin D in milk powder, pulvis elementi compound, mixed proteins, dried meat floss, humanized milk power, children health drink, milk wheat powder and fortified milk. The method is simple, rapid and accurate.

Brain substrates activated by electroacupuncture of different frequencies (I): Comparative study on the expression of oncogene c-fos and genes coding for three opioid peptides

Low and high frequency electroacupuncture (EA)-produced analgesia have been shown to be mediated by different brain substrates and different opioid peptides. In this study, Fos-like immunoreactivity (FLI) and in situ hybridization of the three opioid mRNAs were used to examine the effect of low (2 Hz) and high (100 Hz) frequency EA on neuronal activities, and the expression of opioid genes. 2 Hz and 100 Hz EA induced a markedly different spatial patterns of Fos expression in the rat brain, suggesting there are distinct neuronal pathways underlying EA of different frequencies. Likewise, 2 Hz and 100 Hz EA exert differential effects on opioid gene expression: while 2 Hz EA induced a more extensive and intensive preproenkephalin (PPE) mRNA expression than 100 Hz EA, it had no effect on preprodynorphin (PPD) mRNA expression which was significantly increased by 100 Hz EA stimulation. In contrast, EA of both frequencies did not affect POMC mRNA expression.

Brain substrates activated by electroacupuncture (EA) of different frequencies (II): Role of Fos/Jun proteins in EA-induced transcription of preproenkephalin and preprodynorphin genes

Antisense oligodeoxynucleotides (ODNs) of c-fos and/or c-jun were used in this study to investigate the role of Fos and Jun proteins in electroacupuncture (EA)-induced transcription of the opioid genes, preproenkephalin (PPE), preprodynorphin (PPD) and proopiomelanocortin (POMC). As the results showed, EA-induced Fos and fun expression was blocked efficiently and specifically by e-fos and c-jun antisense ODNs, respectively. This treatment significantly prevented EA-induced PPD, but not PPE, mRNA expression. These results suggest that Fos and Jun proteins are involved in PPD rather than PPE gene transcription activated by EA stimulation.

Segmentation of auditory brainstem response signals

Auditory brainstem responses are used to detect hearing defects in audiology and otoneurology. The use of computer programs for the analysis of such recordings is increasing. To identify their detailed properties a pattern recognition algorithm implemented in an analysis program must be highly reliable. For the recognition process, some preprocessing phases after recording the necessary, such as filtering and often also segmentation. In the following, we will explore segmentation, which can be used in preprocessing of biomedical signals after filtering. We studied linear segmentation, where slopes of short signal segments are computed and divided into different classes according to their values. A segment length of 8 samples for a sampling frequency of 50 kHz employed was best according to our tests and error criteria. Using clustering, we found that less than 10 segment classes is suitable for pattern recognition.

[Expression of retroviral transmembrane envelope protein p15E in human malignant cells]

Malignant tumor growth is always accompanied with immune suppression. Tumor-derived immuno-suppressive factors, among others, are thought to be responsible, but their nature is not well defined. The paper reports on the expression of an immuno-suppressive retroviral transmembrane envelope protein p15E at different levels in human cancer cells. By using immunohistochemistry, enzyme-linked immunosorbent assay, flow cytometry and in situ hybridization, p15E expression could be demonstrated in cancers of the esophagus, nosopharynx, rectum, ovary (including malignant effusion and cell lines), stomach and breast. Enhanced expression of p15E was also observed in activated lymphocytes of cancer patients as shown by RT-PCR technique. The results indicate that p15E of tumor origin, and perhaps that from activated lymphocytes, may contribute to the immune suppression associated with malignancy.

Modulating autoimmune responses to GAD inhibits disease progression and prolongs islet graft survival in diabetes-prone mice

In nonobese diabetic (NOD) mice, beta-cell reactive T-helper type 1 (Th1) responses develop spontaneously and gradually spread, creating a cascade of responses that ultimately destroys the beta-cells. The diversity of the autoreactive T-cell repertoire creates a major obstacle to the development of therapeutics. We show that even in the presence of established Th1 responses, it is possible to induce autoantigen-specific anti-inflammatory Th2 responses. Immune deviation of T-cell responses to the beta-cell autoantigen glutamate decarboxylase (GAD65), induced an active form of self-tolerance that was associated with an inhibition of disease progression in prediabetic mice and prolonged survival of syngeneic islet grafts in diabetic NOD mice. Thus, modulation of autoantigen-specific Th1/Th2 balances may provide a minimally invasive means of downregulating established pathogenic autoimmune responses.

[Factors affecting survival of hepatic carcinoma patients and their clinical significance]

621 patients with unresectable hepatocellular carcinoma were given more than 2 times of intervention treatment. The correlations between the survival rates, tumor histology, portal tumor thrombus and the method and frequency of intervention treatment were analyzed.

RESULTS

(1) The survival rates were higher in cases with single nodular tumor than in those with diffuse-tumors. (2) The survival rates of cases without tumor thrombus in portal system were significantly higher than those with tumor thrombus. However, no correlation was found between the survival rates and the location of thrombus in portal vein. (3) Intraarterial drug infusion combined with lipoidol plus gelatin sponge embolization gave the best therapeutic resalts. (4) How frequent was the intervention would be determined by the patients' general condition and was dependent on the quality of treatment. The cumulative survival rates were greatly affected by the above-mentioned factors. The treatment needs to be individualized.

Insulin and angiotensin II are additive in stimulating TGF-beta 1 and matrix mRNAs in mesangial cells

Angiotensin II (Ang II) and insulin are implicated in the mesangial cell hypertrophy and excessive accumulation of mesangial matrix seen in glomerulosclerosis. Therefore, the effects of Ang II with and without insulin on mRNA levels of several important extracellular matrix genes and transforming growth factor beta-1 (TGF-beta 1) were examined. Ang II alone (1 microM) added to quiescent, murine mesangial cells in serum-free, insulin-free media slightly but not significantly increased TGF-beta 1, fibronectin, collagen I, collagen IV and laminin message levels. The slight elevations in message expression were reversed by losartan, suggesting that these modest effects are mediated by the AT-1 receptor. Ang II alone also had no significant effects on TGF-beta 1 and extracellular matrix message levels in quiescent rat mesangial cells. In contrast, significant increases in mRNA for collagen 1 (6-fold), collagen IV (4-fold), fibronectin 1 (4-fold) and TGF-beta 1 (2-fold) were seen with insulin alone (10(-6)M) in rat mesangial cells, and a dose-response effect could be demonstrated for insulin (10(-9) to 10(-6)M). Ang II plus insulin further significantly increased collagen I (9-fold), collagen IV (9-fold), fibronectin 1 (5-fold) and TGF-beta 1 (3-fold) message expression. These effects were partially reversed in the presence of losartan. The Northern analyses were supported by measurements of active and total TGF-beta 1 activity (pg/ml/ 5 x 10(6) cells): 1145 +/- 76 and 1960 +/- 199, serum free control; 1121 +/- 92 and 1932 +/- 214, Ang II (10(-6)M); 4589 +/- 103 (P < 0.001 vs. control) and 11071 +/- 1952 (P < 0.01 vs. control), insulin (10(-6)M); and 6881 +/- 183 (P < 0.001 vs. control) and 16626 +/- 1435 (P < 0.01 vs. control), insulin plus Ang II. These results suggest that insulin, itself, significantly increases TGF-beta 1 and extracellular matrix gene expression in rat mesangial cells. Ang II alone has modest effects, while Ang II and insulin have additive effects. To explain the mechanism of these additive effects, we investigated the action of Ang II on insulin signaling and the effect of insulin on Ang II AT1 receptor mRNA expression. Ang II did not enhance insulin-induced insulin receptor substrate-1 (IRS-1) phosporylation or phosphatidylinositol3 (PI-3) kinase activity, but did enhance insulin-induced mitogen activated protein (MAP) kinase activity. Insulin increased message levels of AT1 receptor by twofold. These results suggest that enhancement of MAP kinase activity and AT1 receptor regulation by insulin may contribute to the additive effects of insulin and Ang II in mesangial cells.

Functional site in alpha-lactalbumin encompasses a region corresponding to a subsite in lysozyme and parts of two adjacent flexible substructures

Aromatic cluster 1 of alpha-lactalbumin (LA), a substructure adjacent to the cleft, is important for its interaction with galactosyltransferase (GT) and effects on glucose binding in the lactose synthase complex [Grobler, J. A., Wang, M., Pike, A. K., & Brew, K. (1994) J. Biol. Chem. 269, 5106-5114]. The full extent of the functional region in LA has been probed by mutagenesis of residues that are near aromatic cluster 1 or within the cleft that corresponds to the active site in the homologous type c lysozymes. The conserved residues Val42, Gln54, and Ile59, which correspond to residues of lysozyme that act in substrate binding in subsites C to E, together with residues adjacent to aromatic cluster 1, were found to be not required for activity. In contrast, replacing Leu110, a component of the region corresponding to lysozyme subsite F, with His or Glu greatly reduces the affinity of LA for GT while the introduction of Arg lowers the synergism of LA and glucose binding to GT and also reduces the affinity of LA for GT. Substitutions for Ala106, which is adjacent to Leu110 in the structure, also perturb activity. The region of the cleft corresponding to subsite F is important for function in LA as well as in lysozyme since other components of this subsite, His32 and Phe31, are also crucial for LA activity. The qualitatively different effects of various substitutions for Leu110 may be mediated by their influence on His32 or by changes in the structure of the lactose synthase complex.

Exercise echocardiography: feasibility and value for detection of coronary artery disease

OBJECTIVE

To evaluate the feasibility and accuracy of exercise echocardiography (Ex-Echo) for the diagnosis of coronary artery disease (CAD) based on coronary angiography (CA).

PATIENTS AND METHODS

Forty-seven patients were found to have CAD and examined by upright exercise electrocardiography (Ex-ECG) on a treadmill within two weeks of CA. Before and immediately after exercise, the patients lay on a bed beside the treadmill in the left lateral position and parasternal long and short axis and apical two and four chamber views of the heart were acquired. Pre- and post-echocardiograms were analysed in a side-by-side multiple screen format on the imaging view and hypodynamic wall motion of the left ventricle after exercise was defined as Ex-Echo positive. The sensitivity, specificity and predictive accuracy of Ex-Echo and Ex-ECG were calculated on the basis of CA data.

RESULTS

Satisfactory echocardiograms were recorded in 46 patients after exercise. The success rate was 97.8%. Compared with Ex-ECG, Ex-Echo was more sensitive (87.5% vs 62.5%, P < 0.05), specific (92.8% vs 60.0%, P < 0.05) and accurate (89.4% vs 61.7%, P < 0.01). The concord of determining the number of diseased vessels between coronary angiography and Ex-Echo was 90.9% in single vessel disease and 45.0% in multiple vessel disease. Wall motion scoring index, however, was higher in multiple than in single vessel CAD.

CONCLUSIONS

Ex-Echo test is feasible and accurate in detecting CAD and wall motion scoring index is probably useful in distinguishing multiple from single vessel CAD.

C-Fos proteins are not involved in the activation of preproenkephalin gene expression in rat brain by peripheral electric stimulation (electroacupuncture)

The present work was designed to study the role of the oncogene product c-Fos in activating the transcription of preproenkephalin (PPE) gene following a kind of peripheral electric stimulation known as electroacupuncture (EA) stimulation. The temporal patterns of rat brain c-fos and PPE mRNA expression were evaluated using the method of Northern blotting, showing that c-fos mRNA expression, which peaked at 2 h after the termination of EA, was always ahead of the PPE mRNA expression which began at 4 h and peaked at 48 h after EA. The methods of immunocytochemistry (ICC) and in situ hybridization (ISH) techniques were combined to identify the co-existence of c-Fos protein and PPE mRNA at the cellular level. The results showed that only a small percentage of PPE mRNA-containing neurons depicts Fos-like immunoreactive nuclei. These findings suggest that c-Fos protein may not be involved in the activation of brain PPE gene transcription induced by peripheral electric stimulation.

Nasal administration of glutamate decarboxylase (GAD65) peptides induces Th2 responses and prevents murine insulin-dependent diabetes

We previously demonstrated that a spontaneous Th1 response against glutamate decarboxylase (GAD65) arises in NOD mice at four weeks in age and subsequently T cell autoimmunity spreads both intramolecularly and intermolecularly. Induction of passive tolerance to GAD65, through inactivation of reactive T cells before the onset of autoimmunity, prevented determinant spreading and the development of insulin-dependent diabetes mellitus (IDDM). Here, we examined whether an alternative strategy, designed to induce active tolerance via the engagement of Th2 immune responses to GAD65, before the spontaneous onset of autoimmunity, could inhibit the cascade of Th1 responses that lead to IDDM. We observed that a single intranasal administration of GAD65 peptides to 2-3-wk-old NOD mice induced high levels of IgG1 antibodies to GAD65. GAD65 peptide treated mice displayed greatly reduced IFN gamma responses and increased IL-5 responses to GAD65, confirming the diversion of the spontaneous GAD65 Th1 response toward a Th2 phenotype. Consistent with the induction of an active tolerance mechanism, splenic CD4+ (but not CD8+) T cells from GAD65 peptide-treated mice, inhibited the adoptive transfer of IDDM to NOD-scid/scid mice. This active mechanism not only inhibited the development of proliferative T cell responses to GAD65, it also limited the expansion of autoreactive T cell responses to other beta cell antigens (i.e., determinant spreading). Finally, GAD65 peptide treatment reduced insulitis and long-term IDDM incidence. Collectively, these data suggest that the nasal administration of GAD65 peptides induces a Th2 cell response that inhibits the spontaneous development of autoreactive Th1 responses and the progression of beta cell autoimmunity in NOD mice.

Constitutively active G(S) alpha-subunits stimulate Pit-1 promoter activity via a protein kinase A-mediated pathway acting through deoxyribonucleic acid binding sites both for Pit-1 and for adenosine 3',5'-monophosphate response element-binding protein

Constitutively active mutations of the G protein alpha(S) subunit are detected at a high frequency in human pituitary adenomas that secrete GH or PRL. It seems possible that over-expression of the pituitary cell-specific transcription factor Pit-1/GHF-1 (Pit-1) gene in response to active alpha(S) subunits contributes to the formation of these adenomas. We have examined whether expression in pituitary cells of one of these constitutively active alpha(S) subunits, Q227L-alpha(S), stimulates expression directed by the Pit-1 promoter. Transient expression of Q227L-alpha(S) yielded a strong stimulation of a target Pit-1 promoter-chloramphenicol acetyl transferase (CAT) construct, (-200)Pit-1-CAT. Expression of wild-type alpha(S) or an inactive alpha(S) mutant yielded, respectively, reduced or no stimulation of CAT activity. A dominant inhibitor of protein kinase A (PKA), RAB, blocked almost completely either forskolin (FSK) or Q227L-alpha(S) stimulation of (-200)Pit-1-CAT expression, implying that PKA is required for the action of Q227L-alpha(S) on the Pit-1 promoter. The Pit-1 promoter contains a binding site for Pit-1 and two CREB binding sites. Mutation of the Pit-1 binding site reduced but did not eliminate either FSK or Q227L-alpha(S) stimulation of Pit-1 promoter activity, implying a partial but incomplete requirement for this element for a PKA-mediated response to Q227L-alpha(S). The CREB dominant inhibitor S133A-CREB yielded a partial reduction in either FSK or Q227L-alpha(S) stimulation of (-200)Pit-1-CAT expression, implying that one or both of the Pit-1 promoter adenosine 3'5'-monophosphate response element binding protein (CREB) binding sites is/are also required for a complete PKA-mediated response to Q227L-alpha(S). The observation that S133A-CREB completely blocked the response to FSK or Q227L-alpha(S) of a Pit-1 promoter containing a mutated site PitB1 implies that the binding sites for Pit-1 and CREB account for all of the response elements for FSK or alpha(S) in the Pit-1 promoter.

[Constituents of essential oil of imported myrrh and gum opoponax]

The constitutents of essential oil in two kinds of Myrrha were analyzed by GC-MS. Fifteen compounds in Myrrh and thirty-three compounds in Gum opoponax were identified with their percent contents given. The main constituent of Myrrh is furanoeudesma-1,3-diene, and the main constituent of Gum opoponax is beta-trans-ocimene.

[A study on risk factors of neural tube defects]

One hundred and twenty-three cases with neural tube defects collected during 1991 to 1993 from 12 hospitals with birth defect surveillance in Hebei Province, and their pair-matched controls were analyzed with single and multiple conditional logistic regression to study the effects of food and drinking water on occurrence of neural tube defects. Results showed factors contributing to neural tube defects were maternal previous history of birth defects, much consumption of dried and pickled vegetables during pregnancy, too much nitrate content in drinking water (containing more than 10 mg nitrogen per liter of water), less consumption of meat, eggs, and beans in their diet.

Impaired agonist-induced calcium signaling in hepatocytes from chronic renal failure rats

Some hormones exert their action by inducing a rise in cytosolic calcium [Ca2+]i (calcium signal), and therefore, a blunting in hormone-induced calcium signal would engender resistance to the action of the hormone. Chronic renal failure (CRF) is associated with resistance to the action of a variety of hormones, a rise in [Ca2+]i and decrease in the amount of mRNA of one hormone receptor, the PTH-PTHrP receptor. We examined the calcium-signal induced by PTH, angiotensin II, vasopressin and glucagon in hepatocytes from CRF animals, evaluated the effect of the basal level [Ca2+]i on the calcium signal and explored the effect of [Ca2+]i on the mRNA of the receptors of these agonists. Hepatocytes from CRF rats have elevated basal levels of [Ca2+]i and display significantly reduced calcium signals induced by all these hormones, while the calcium signals were normal in PTX-CRF animals and those treated with verapamil both of which have normal levels of [Ca2+]i despite CRF. The calcium signals induced by dibutyryl cyclic AMP and G protein activator (GTP gamma S) were normal in hepatocytes from CRF animals despite the high levels of [Ca2+]i. Northern blotting experiments revealed that the levels of the mRNA of the receptors of PTH-PTHrP, angiotensin II and vasopressin were significantly reduced in hepatocytes from CRF animals but PTX-CRF rats and those treated with verapamil had either significantly greater or even normal amounts of the mRNA of these receptors.(ABSTRACT TRUNCATED AT 250 WORDS)

Decreased atherosclerosis in mice deficient in both macrophage colony-stimulating factor (op) and apolipoprotein E

To develop a murine model system to test the role of monocyte-derived macrophage in atherosclerosis, the osteopetrotic (op) mutation in the macrophage colony-stimulating factor gene was bred onto the apolipoprotein E (apoE)-deficient background. The doubly mutant (op/apoE-deficient) mice fed a low-fat chow diet had significantly smaller proximal aortic lesions at an earlier stage of progression than their apoE-deficient control littermates. These lesions in the doubly mutant mice were composed of macrophage foam cells. The op/apoE-deficient mice also had decreased body weights, decreased blood monocyte differentials, and increased mean cholesterol levels of approximately 1300 mg/dl. Statistical analysis determined that atherosclerosis lesion area was significantly affected by the op genotype and gender. The confounding variables of body weight, plasma cholesterol, and monocyte differential, which were all affected by op genotype, had no significant additional effect on lesion area once they were adjusted for the effects of op genotype and gender. Unexpectedly, there was a significant inverse correlation between plasma cholesterol and lesion area, implying that each may be the result of a common effect of macrophage colony-stimulating factor levels. The data support the hypothesis that macrophage colony-stimulating factor and its effects on macrophage development and function play a key role in atherogenesis.

Constitutively active Gq-alpha stimulates prolactin promoter activity via a pathway involving Raf activity

We have investigated the ability of a constitutively active Gq-alpha mutant, Q209L-alpha q, to regulate target gene expression. Transient expression in GH3 pituitary cells of a rat proximal prolactin promoter-chloramphenicol acetyltransferase construct (-187)PRL-CAT, was stimulated by co-expression of Q209L alpha q, but not by wild-type alpha q. Q209L-alpha q stimulated expression of constructs driven by promoters for either rat prolactin or growth hormone, but not of a control construct driven by the thymidine kinase promoter. Thus, transcriptional effects of alpha q are specific both for the activated state of this G-alpha subunit and the promoter examined. Since both the prolactin and growth hormone promoters are activated by the pituitary cell-specific transcription factor Pit-1, we examined whether a Pit-1 binding site could direct a response to Q209L-alpha q. Two copies of prolactin promoter Pit-1 binding site 1P conferred upon a heterologous metallothionein promoter a response to Q209L-alpha q, implying an involvement of this site in the transcriptional action of Q209L-alpha q on the prolactin promoter. The phorbol ester activator of protein kinase C, 12-O-tetradecanoylphorbol-13-acetate, stimulated (-187)PRL-CAT activity, but opposed the action of Q209L-alpha q on activity of this PRL-CAT construct. Q209L-alpha q stimulation of (-187)PRL-CAT activity was inhibited by co-expression of a dominant negative Raf mutant, Raf-C4, but not by a point mutant of Raf-C4 with reduced inhibitory properties. These results imply that activated alpha q subunits can stimulate prolactin promoter activity via a pathway that involves a Pit-1 DNA binding site(s), is opposed by protein kinase C, and is mediated by a pathway in which Raf-1 kinase plays a role.

Characterization of the murine mu opioid receptor gene

The analgesic and addictive properties of morphine and other opioid drugs are thought to result from their interaction with mu opioid receptors. Using a delta opioid receptor cDNA as a probe, we have isolated a murine mu opioid receptor cDNA clone (mMOR). Stable expression of mMOR in Chinese hamster ovary cells conferred high binding affinity for mu receptor ligands including morphine and [D-Ala2,N-methyl-Phe4,Gly5-ol]-enkephalin and low affinity for delta and kappa preferring ligands. Treatment of these cell lines with morphine and other mu agonists inhibited forskolin-induced cAMP accumulation, demonstrating a functional coupling of mMOR to the inhibition of adenylate cyclase. The predicted amino acid sequence of mMOR shares approximately 55% overall amino acid identity with the delta receptor and approximately 97% identity with the recently reported rat mu opioid receptor. Expression of the mu receptor in mouse brain as revealed by in situ hybridization parallels the reported pattern of distribution of mu-selective ligand binding sites. Chromosomal localization (to mouse chromosome 10) and Southern analysis are consistent with a single mu opioid receptor gene in the mouse genome, suggesting that the various pharmacologically distinct forms of the mu receptor arise from alternative splicing, post-translational events, or from a highly divergent gene(s).