Expression of functional cytochrome P4501A1 in human embryonic hepatic tissues during organogenesis

Investigations with chemical inhibitors and with inhibitory antibodies specific for cytochrome P4501A-catalyzed ethoxyresorufin (ethoxyphenoxazone) O-deethylation and 2-acetylaminofluorene (N-2-fluorenylacetamide) ring hydroxylation indicated that cytochrome(s) P450 of the 1A subfamily was functionally expressed in human embryonic hepatic tissues at very early stages (days 50-60) of gestation. Lack of detectable capacity of hepatic microsomal enzymes to catalyze either N-hydroxylation of 2-acetylaminofluorene or O-demethylation of methoxyresorufin indicated that functional cytochrome P4501A2 is expressed minimally or negligibly in human embryonic hepatic tissues. By contrast, profound inhibition of the ring hydroxylation of 2-acetylaminofluorene and of the O-deethylation of ethoxyresorufin by 7,8-benzoflavone as well as by anti-cytochrome P4501A1 antibodies indicated the presence of significant levels of functional cytochrome P4501A1 in hepatic microsomes of human embryos. Using the reverse transcriptase-linked polymerase chain reaction with specific oligonucleotide primers, we also detected significant expression of cytochrome P4501A1 mRNA in human embryonic livers. Polymerase chain reaction amplification, cloning and sequencing of the corresponding cDNA provided evidence that the cytochrome P4501A1 mRNA expressed in human embryonic tissues was identical to that expressed in adult human tissues. The results of the study have important implications in terms of the embryotoxic effects of chemicals that are known to be substrates, inhibitors or inducers of cytochrome P4501A1 and to which pregnant women are exposed.

Homotypic interactions of chicken GATA-1 can mediate transcriptional activation

We used a one-hybrid system to replace precisely the finger II chicken GATA-1 DNA-binding domain with the binding domain of bacterial repressor protein LexA. The LexA DNA-binding domain lacks amino acids that function for transcriptional activation, nuclear localization, or protein dimerization. This allowed us to analyze activities of GATA-1 sequences distinct from DNA binding. We found that strong transcriptional activating sequences that function independently of finger II are present in GATA-1. Sequences including finger I contain an independent nuclear localizing function. Our data are consistent with cooperative binding of two LexA-GATA-1 hybrid proteins on a palindromic operator. The sensitivity of our transcription assay provides the first evidence that GATA-1 can make homotypic interactions in vivo. The ability of a non-DNA-binding form of GATA-1 to activate gene expression by targeting to a bound GATA-1 derivative further supports the notion that GATA-1-GATA-1 interactions may have functional consequences. A coimmunoprecipitation assay was used to demonstrate that GATA-1 multimeric complexes form in solution by protein-protein interaction. The novel ability of GATA-1 to interact homotypically may be important for the formation of higher-order structures among distant regulatory elements that share binding sites for this transcription factor. We also used the system to test the ability of GATA-1 to interact heterotypically with other activators.

Direct sub-Tenon's ocular anesthesia for strabismus surgery

We assessed the safety and effectiveness of sub-Tenon's anesthesia, a local anesthesia, for strabismus surgery. For 15 surgeries, we used anesthesia by sub-Tenon's infusion, followed by direct infusion through a transconjunctival route with a local anesthetic agent. We found the procedure was simple, it minimized complications compared with other techniques and was effective in achieving rapid anesthesia. With the ocular movement remaining, we checked eye position by the alternative cover-uncover test at the end of surgery. We obtained good eye position for all patients. This method leads to good results for strabismus surgery.

Role of transesophageal echocardiography in pre- and post-percutaneous balloon mitral valvuloplasty

Transesophageal echocardiogram (TEE) was performed in 33 consecutive patients with both rheumatic mitral stenosis and chronic atrial fibrillation to evaluate the usefulness of this technique for the detection of left atrial thrombi, mitral regurgitation before percutaneous balloon mitral valvuloplasty and iatrogenic atrial septal defect after the procedure. TEE correctly identified thrombi in 10 (30%) patients and significant mitral regurgitation in 5 patients who underwent surgical intervention. The remaining 18 patients underwent percutaneous balloon mitral valvuloplasty without evidence of systemic embolic event and obtained adequate outcome. Transesophageal color doppler echocardiography demonstrated left-to-right shunting flow through atrial septum in 5 of 7(71%) patients 3 days after the procedure and repeated TEE in 2 of these 5 patients showed no shunting after 6 months. In conclusion, TEE plays a definite role in the selection of patients for balloon mitral valvuloplasty and assessment of iatrogenic atrial septal defect.

Functional cytochrome P4503A isoforms in human embryonic tissues: expression during organogenesis

Expression of functional cytochrome P450 (CYP) isoforms in human embryonic tissues was explored during organogenesis (days 50-60 of gestation) with substrate probes, inhibitor probes, and immunoprobes and by reverse transcription-polymerase chain reaction (PCR), cloning, and sequencing. Evidence was obtained for the presence of relatively high levels of one or more functional CYP3A isoforms in embryonic livers. This was manifested as relatively extensive hydroxylation of (R)-warfarin at carbon 10 and as triacetyloleandomycin-inhibited O-debenzylation of benzyloxyresorufin when human embryonic hepatic microsomal fractions were used as enzyme sources. Immunoblots with anti-CYP3A4 antibody exhibited a strong signal in embryonic hepatic tissues but, in contrast, indicated very low or negligible CYP3A levels in human embryonic lung, kidney, heart, adrenal, and brain tissues. To explore expression of individual members of the CYP3A subfamily in human embryonic hepatic tissues at this early gestational stage, CYP3A cDNA was generated by reverse transcription, amplified by PCR, cloned, and sequenced. Oligonucleotide primers used for PCR were designed to flank target sequences unique to CYP3A but also common to all human CYP3A subfamily members for which GenBank nucleotide sequence information was available (CYP3A3, CYP3A4, CYP3A5, CYP3A5P, and CYP3A7). Sequencing data indicated that plasmids in 58 of 59 recombinant positive colonies contained an insert with a sequence identical to that present in CYP3A7 cDNA and the plasmid of only one colony contained an insert with a sequence identical to that present in CYP3A5 cDNA. No evidence was found for expression of CYP3A3 or CYP3A4. Thus, during organogenesis, human embryonic hepatic tissues express primarily CYP3A7 and are capable of significant CYP3A7-catalyzed xenobiotic monooxygenation during this very early stage of gestation.

Induction in vitro and complete coding region sequence of cytochrome P4501A1 cDNA from cultured whole rat conceptuses during early organogenesis

Exposures of cultured whole rat conceptuses during organogenesis to 3-methylcholanthrene (MC; 0.025-25 microM), 5,6-benzoflavone (BNF; 5-100 microM) or benz[a]anthracene (BA; 5-100 microM) were effected by placement of each of these "MC-type" inducing agents in the culture medium at the time of explantation on day 9.5 of gestation. Conceptuses were then cultured for 48 hr and evaluated on day 11.5 for increased expression of inducible conceptal cytochrome P450 (P450). The three agents each elicited concentration-dependent increases in 7,8-benzoflavone (ANF)-inhibitable ethoxyresorufin O-deethylase (EROD) activities and increased P4501A1 mRNA as detected by primer-specific reverse transcriptase-polymerase chain reaction (RT-PCR) in cell-free preparations of the treated, cultured conceptuses. At effective inducing concentrations, dysmorphogenic or other embryotoxic effects were not detectable. At 20 microM concentrations, the three agents exhibited roughly equal induction that was approximately equivalent in magnitude (6- to 13-fold) to that achieved previously with exposures to MC in utero. Additions to the culture medium of 2.5 to 10 microM concentrations of dexamethasone (DEX) did not alter significantly the magnitude of MC-elicited induction in vitro. Repeated full-length sequencing of an RT-PCR-amplified cDNA revealed a coding region sequence identical to that reported for the P4501A1 sequence from adult rat liver. The results provide a basis for investigations, in the absence of maternal influences, of the regulation of mammalian conceptal P4501A1 in intact tissues during organogenesis, a gestational period critical in terms of the dysmorphogenic and other embryotoxic effects of foreign organic chemicals. The results are also pertinent to studies of embryotoxicity, particularly to the transplacental carcinogenicity, mutagenicity and dysmorphogenicity of P4501A1 substrates.

[The metastatic pattern of malignant tumors]

Four hundred autopsy cases of malignant tumors were analysed. Of these 321 cases (80.3%) had carcinoma and 79 (19.7%) sarcoma. In the 79 cases, 65 had malignant lymphoma, and 14 (3.5%) soft tissue and bone tumor. The tumor cells metastatic to the lung and liver were common in the autopsy cases. There were 163 cases of metastatic tumors in the lung and liver respectively (40.5%). The metastatic tumor in the liver was mainly from the breast, large intestinal, ovary, stomach and NHL, and in the lung mainly from the breast, liver, NHL, stomach and ovary. The lymph node metastasis was mainly located in the neck, mediastina, aorta. The extensive metastatic tumors were lung cancer, gastric cancer, breast cancer and NHL, However, carcinoma in uterus cervix, urinary bladder, pharynex and testis was mainly infiltrated in the original region. The tumor metastasis was related to the region, histologic type and differentiation and so on.

Helicobacter pylori infection and chronic active gastritis

Helicobacter pylori (H. pylori) is an S-Shaped, gram-negative bacillus that recently has been implicated in the pathogenesis of chronic active gastritis and other peptic ulcer disease. These findings have encouraged gastroenterologists to provide a new rationale for patient management, with hope of providing more successful treatment of peptic ulcer disease, particularly gastritis. Therefore, a cooperative diagnostic effort was made at the pathology laboratory of St Francis Medical Center to adopt a simple and reliable method for the identification of H. pylori in tissue sections of endoscopic biopsies of stomach and duodenum. We attempted to estimate the prevalence of H. pylori infection in patients biopsied for upper Gl disorders who were refractory to medication. A prevalence of H. pylori infection among different ethnic groups also was studied.

Proteins of the intermediate filament cytoskeleton as markers for astrocytes and human astrocytomas

There is a pressing need for a more accurate system of classifying human astrocytomas, one that is based on morphologic characteristics and that could also make use of distinctive biochemical markers. However, little is known about the phenotypic characteristics of astrocytomas. Recent studies have shown that the expression of proteins comprising the intermediate filament (IF) cytoskeleton of astrocytic cells is developmentally regulated. It is our hypothesis that this changing protein profile can be used as the basis of a system for clearly and objectively classifying astrocytomas. A spectrum of human astrocytomas has been examined by immunofluorescence microscopy employing antibodies to several IF structural subunit proteins (GFAP, vimentin, and keratins) and an IF-associated protein, IFAP-300kDa. These proteins occupy unique temporal niches in the cytogenesis of the astrocytic cells: keratins in cells of the neuroectoderm; vimentin and IFAP-300kDa in radial glia and immature glia; GFAP in mature astrocytes; and vimentin in some mature astrocytes. In agreement with previous reports, our immunofluorescence studies have revealed both GFAP and vimentin in all astrocytoma specimens. Two new observations, however, are of particular interest: IFAP-300kDa is detectable in all astrocytic tumors, and the proportion of keratin-containing cells present in the astrocytomas is in direct relationship to the degree of the malignancy. Because IFAP-300kDa is not present in either normal mature or reactive astrocytes, this protein appears to represent a specific marker of transformed (malignant) astrocytes. If it is presumed that higher malignancy grades represent the most dedifferentiated cellular state of the astrocytes, the presence of keratin-containing cells is not totally unexpected, given the ectodermal (epithelial) origin of the CNS. Specific developmentally regulated proteins of the IF cytoskeleton thus appear to hold great potential as diagnostic markers of astrocytomas and as tools for investigating the biology of these tumors.

The nature of conditioned anti-analgesia: spinal cord opiate and anti-opiate neurochemistry

The central nervous system contains circuitry that inhibits pain sensitivity (analgesia), as well as circuitry that opposes pain inhibition (anti-analgesia). Activation of analgesia systems and anti-analgesia systems can each be brought under environmental control using classical conditioning procedures. Analgesia can be produced by cues present before and during aversive events such as electric shock, while active inhibition of analgesia comes to be produced by cues never present immediately before or during shock and therefore signal safety. We have recently reported that these analgesia and anti-analgesia systems interact at the level of the spinal cord. A series of 3 experiments were performed to examine how such interactions occur. First, potential opioid mediation of conditioned analgesia was investigated using systemic and intrathecal (i.t.) delivery of opiate antagonists. Conditioned analgesia was found to be mediated by activation of spinal mu and delta opiate receptors. Second, analgesia produced by each of these receptor subtypes was challenged by environmental signals for safety. Analgesias produced by mu and delta opiate agonists were each abolished by safety signals. Third, antagonists/antisera directed against several putative anti-opiate neurotransmitters were tested i.t. to identify which mediate conditioned anti-analgesia at the level of the spinal cord. A cholecystokinin antagonist abolished conditioned anti-analgesia. In contrast, neuropeptide FF antiserum and a kappa opiate antagonist were without effect.

Origin of neurohypophyseal neuropeptide-FF (FLFQPQRF-NH2)

Neuropeptide-FF (FLFQPQRF-NH2), originally isolated from bovine brain, is an FMRF-NH2-like peptide with morphine-modulating activity. Neuropeptide-FF (NPFF) is unevenly distributed in the central nervous system, with the highest concentrations in posterior pituitary and spinal cord. In the rat pituitary, NPFF is found exclusively in the neural lobe, where it is localized in nerve terminals and fibers, indicating the hypothalamus as a possible source of the neural lobe NPFF. In this study the origin of neurohypophyseal NPFF was investigated using various hypothalamic lesions and an anterograde tracing experiment. The results suggest that at least part of the neurohypophyseal NPFF originates from the supraoptic nucleus and may be localized in some of the arginine vasopressin-containing magnocellular neurons.

Neuropeptide FF receptors: structure-activity relationship and effect of morphine

Neuropeptide FF (FLFQPQRFamide, NPFF) is an octapeptide implicated in morphine analgesia, tolerance and dependence. Many of the behavioral effects of NPFF have also been observed with the invertebrate neuropeptide Phe-Met-Arg-Phe-amide (FMRFamide), which binds to NPFF receptors because of its low homology to the C-terminal portion of NPFF. A competitive ligand binding assay was used to characterize NPFF receptors in rat spinal cord and a strong requirement was found for the C-terminal Arg-Phe-amide. It was found that FMRFamide (Ki = 1.8 nM) bound with lower affinity than NPFF (0.26 nM) but it was about 7-fold more potent than PQRFamide (12 nM). This finding explains the similar bioactivities of NPFF and FMRFamide. The Gln2 appeared to be the cause of the relatively low potency of PQRFamide, based on the binding specificity of NPFF receptors for a series of FMRFamide analogs. In contrast to the Arg-Phe-amide, substitutions at the first and second positions of FMRFamide were generally tolerated, with the most potent analogs being PMRFamide (Ki = 0.54 nM), FFRFamide (0.25 nM) and FWRFamide (0.42 nM). Among the most potent ligands was a pentapeptide containing a photoreactive Phe analog, D-Tyr-(p-benzoyl-Phe)-norLeu-Arg-Phe-amide (Ki = 0.23 nM). It was found that dansyl-PQRFamide and dansyl-RFamide also bound to NPFF receptors with Ki values of 6.1 and 73 nM, respectively. The radioligand binding and G-protein coupling of NPFF receptors were not altered by chronic morphine treatment.

Expression of 300-kilodalton intermediate filament-associated protein distinguishes human glioma cells from normal astrocytes

The availability of biochemical markers to distinguish glioma cells from normal astrocytes would have enormous diagnostic value. Such markers also may be of value in studying the basic biology of human astrocytomas. The vimentin-binding, 300-kDa intermediate filament (IF)-associated protein (IFAP-300kDa) has recently been shown to be developmentally expressed in radial glia of the central nervous system of the rat. It is not detected in the normal or reactive astrocytes of the adult rat nor in neonatal rat brain astrocytes in primary culture. In the present study, double-label immunofluorescence microscopy using antibodies to IFAP-300kDa and glial fibrillary acidic protein (GFAP, an astrocyte-specific IF structural protein) identifies this IFAP in GFAP-containing tumor cells from examples of all three major types of human astrocytomas (i.e., well-differentiated, anaplastic, and glioblastoma multiforme). Astrocytoma cells in primary cultures prepared from all three astrocytomas also express this protein. It is not detectable in normal adult brain tissue. Immunoblot analyses using the IFAP-300kDa antibody confirm the presence of a 300-kDa polypeptide in fresh astrocytoma preparations enriched for IF proteins. These results suggest the utility of IFAP-300kDa as a marker for identification of human glioma cells both in vitro and in situ.

Immunotyping of radial glia and their glial derivatives during development of the rat spinal cord

The differentiation of glia in the central nervous system is not well understood. A major problem is the absence of an objective identification system for involved cells, particularly the early-appearing radial glia. The intermediate filament structural proteins vimentin and glial fibrillary acidic protein have been used to define the early and late stages, respectively, of astrocyte development. However, because of the non-specificity of vimentin and the temporal overlap in expression patterns of both proteins, it is difficult to refine our view of the process. This is especially true of the early differentiation events involving radial glia. Using the developmentally-expressed intermediate filament-associated protein IFAP-70/280 kD in conjunction with vimentin and glial fibrillary acidic protein markers, a comprehensive investigation of this problem was undertaken using immunofluorescence microscopy of developing rat spinal cord (E13-P28 plus adult). The phenotypes of the cells were defined on the basis of their immunologic composition with respect to IFAP-70/280 kD (I), vimentin (V) and GFAP (G). A definitive immunotype for radial glia was established, viz, I+/V+/G-; thus reliance upon strictly morphological criteria for this early developmental cell was no longer necessary. Based upon the immunotypes of the cells involved, four major stages of macroglial development were delineated: (1) radial glia (I+/V+/G-); (2) macroglial progenitors (I+/V+/G+); (3) immature macroglia (I-/V+/G+); and (4) mature astrocytes (I-/V+/G+ primarily in white matter and I-/V-/G+, the predominant type in gray matter). It is of interest to note that the cells of the floor plate were distinguished from radial glia by their lack of IFAP-70/280 kD immunoreactivity. Introduction of the IFAP-70/280 kD marker has therefore provided a more refined interpretation of the various differentiation stages from radial glia to mature astrocytes.

Antiserum against neuropeptide Y enhances the nicotine-mediated release of catecholamines from cultured rat adrenal chromaffin cells

A primary culture of chromaffin cells was prepared from adult rats and the stability of cell contents, NPY and catecholamines (CAs), during the culture was studied. The responsiveness of cultured chromaffin cells to NGF or secretagogues and the possible role of NPY on the CA secretion from cultured chromaffin cells were investigated. After plating of isolated cells, there was marked decrease in the cell content of CAs but a significant increase in the cell content of NPY. Though both NPY and CAs in the cultured cells were positively regulated by NGF, the results of this study seemed to suggest a differential regulation for NPY and CAs in the chromaffin cell. The cultured chromaffin cells secreted NPY and CAs in response to stimulation by nicotine. The nicotine stimulated secretion of CA was enhanced by the presence of IgG fraction, prepared from NPY antiserum, in the secretion medium. The results suggested that NPY was co-released with CAs from chromaffin cells and then acted as a modulator on CA secretion.

[Absent pulmonary valve syndrome in tetralogy of Fallot: report of two cases]

A combination of absence of the pulmonary valve with ventricular septal defect, annular pulmonary stenosis and aneurysm of the pulmonary artery is called "absent pulmonary valve syndrome". Most patients with this condition suffered from severe respiratory symptoms in early infancy. Respiratory failure which is the leading cause of mortality in infants with this syndrome, results from pulmonary emphysema, pulmonary atelectasis or pulmonary infection as a consequence of compression of the bronchus by the pulmonary aneurysm. If these patients can be treated medically to survive beyond one year old, gradual decrease in severity of symptoms is expected. A definite correction in childhood is recommended. Otherwise, palliative operation in infancy has a high mortality rate. This paper reported two cases with severe symptoms in infancy; one patient expired at nine months of age, and the other lived beyond one year to receive surgical correction at the age of three. The etiology, clinical features and treatment of absent pulmonary valve syndrome are also discussed.

Modulation of neuropeptide FF receptors by guanine nucleotides and cations in membranes of rat brain and spinal cord

Using a radioligand binding assay, we examined ionic modulation and G protein coupling of neuropeptide FF (NPFF) receptors in membranes of rat brain and spinal cord. We found that NaCl (but not KCl or LiCl) and MgCl2 increased specific 125I-YLFQPQRFamide (125I-Y8Fa) binding to NPFF receptors in both tissues in a dose-dependent manner, with optimal conditions being 60 mM NaCl and 1 mM MgCl2. Guanine nucleotides dose-dependently inhibited specific 125I-Y8Fa binding to rat brain and spinal cord membranes with maximal effects of 64 +/- 6 and 71 +/- 2%, respectively. The order of potency was nonhydrolyzable GTP analogues > GTP > or = GDP >> GMP, ATP. The guanine nucleotide inhibition was observed in the absence and presence of NaCl and MgCl2. The mechanism of inhibition in spinal cord membranes appeared to be a reduction in the number of NPFF receptors; in one experiment, control KD and Bmax values were 0.068 nM and 7.2 fmol/mg of protein, respectively, and with 0.1 microM guanylylimidodiphosphate the respective values were 0.081 nM and 4.9 fmol/mg, a 32% reduction in receptor number. Similar results were obtained with guanosine 5'-O-(3-thiotriphosphate). Our data suggest that 125I-Y8Fa binding sites in rat CNS are G protein-coupled NPFF receptors regulated by GTP and cations.

Distinct associations of HLA class II genes with inflammatory bowel disease

BACKGROUND

There are relatively few studies of HLA class II association either with Crohn's disease (CD) or ulcerative colitis (UC). The few available association studies have been carried out by serological techniques, and the results from these studies are inconclusive.

METHODS

The association between HLA class II genes was studied using molecular genotyping in combination with allele-specific oligonucleotide hybridization by polymerase chain reactions.

RESULTS

In UC (n = 74), we observed a positive association with the HLA DR2 allele (P = 0.008) and negative associations with the DR4 (P = 0.018) and DRw6 (P = 0.028) when compared with ethnically matched controls (n = 77). No associations were observed with any DQ alleles. In contrast, in CD (n = 95) we observed a positive association with the combination of DR1 and DQw5 alleles (P = 0.021). Furthermore, stratifying DR1 and DQw5 alleles indicated that neither allele was independently associated with CD, suggesting that the association was with the haplotype rather than either of the alleles individually. A suballele of DQw5, DQB1*0501, contributed this haplotypic association (P = 0.012).

CONCLUSIONS

DR and DQ molecules firmly separate UC and CD on genetic grounds, suggesting that the contribution of the HLA class II genes to the disease susceptibility is quite different for the two disorders.

Hemodynamic evaluation of bovine pericardial xenograft valves in the mitral position by stress Doppler echocardiography

The function of a bovine pericardial xenograft valve in the mitral position was studied in 18 patients by using stress Doppler echocardiography after submaximal supine exercise. In 10 patients with normally functioning tissue valve, peak and mean gradients increased from 9.3 +/- 1.3 and 2.7 +/- 0.7 mmHg, respectively at rest, to 14.7 +/- 0.9 and 4.1 +/- 1.0 mmHg at peak exercise. The tissue valve area assessed by the Doppler pressure half-time method increased from 2.69 +/- 0.38 cm2 at rest, to 3.15 +/- 0.38 cm2 at peak exercise (P < 0.05). In 6 patients with mitral regurgitation, peak and mean gradients increased from 17.3 +/- 5.3 and 7.0 +/- 1.8 mmHg, respectively at rest, to 24.3 +/- 5.0 and 9.0 +/- 2.6 mmHg at peak exercise, but there was no significant change in valve area at peak exercise. Patients with severe isolated mitral regurgitation had a Vmax of more than 2 m/s and elevated pressure gradients at peak exercise. But the pressure half-time was relatively unaffected, allowing their differentiation from patients with tissue valvular stenosis. Stress Doppler echocardiography is a simple, noninvasive and reliable method for the evaluation of the mitral tissue valve function which is recommendable for patients with suspected mitral tissue valve dysfunction.

Subcutaneous injection of an analog of neuropeptide FF precipitates morphine abstinence syndrome

Neuropeptide FF (NPFF) has been shown to exert various antiopiate actions, including precipitation of opiate abstinence syndrome by third ventricle injection in morphine dependent rats. In the present study, dansyl-Pro-Gln-Arg-Phe-amide, a lipophilic analog of NPFF, was injected into morphine dependent rats and appropriate sham controls at a dose of 9 mg/kg s.c. Comparison groups were injected with ethanol/water vehicle alone. The NPFF analog precipitated a vigorous opiate abstinence syndrome in morphine dependent rats, but not in sham controls.

[Experimental study on the action of EDTA-liposome to remove mercury from the mice given methylmercury chloride]

It was reported that experimental study on the action of EDTA-Liposome to remove mercury from the mice given methylmercury chloride showed that elimination of methylmercury chloride from brain, testicle, liver, kidney and blood of mice treated by EDTA-Liposome was more significant than that of mice treated by EDTA alone. Mercury level in feces of EDTA-Liposome treated group increased significantly (P < 0.001). The advantages of treatment with EDTA-Liposome were discussed. Applying EDTA-Liposome is an efficient method in therapy of metal poisoning.

Release of neuropeptide FF (FLFQPQRF-NH2) from rat spinal cord

Neuropeptide FF (FLFQPQRF-NH2), originally isolated from bovine brain, is an FMRF-NH2-like peptide with morphine-modulating activity. Neuropeptide FF (NPFF) is highly localized in the dorsal spinal cords where there are also specific NPFF binding sites. Furthermore, there have been studies indicating that NPFF may participate in the regulation of pain threshold in the spinal cord. However, whether NPFF can be released from the spinal cord is not known. The present experiments, using an in vitro superfusion of an isolated whole rat spinal cord, demonstrated that high concentrations of KCl or substance P caused a release of NPFF immunoreactive material (IR) from the spinal cord into the perfusion medium in a calcium-dependent manner. Substance P (1-11) also produced a detectable release of NPFF-IR in vivo although the response was quite variable. The released NPFF-IR was analyzed by an HPLC study and found to consist of NPFF and other minor immunoreactive peptides. Further studies with substance P-related peptides showed that the in vitro release of NPFF-IR could also be induced by substance P (1-7) but not by [pGlu5,Me-Phe8,Sar9]-substance P (5-11) or substance K. These results suggest that the specific substance P receptor (SP-N), which is recognized by both substance P (1-11) and substance P (1-7) rather than the tachykinin receptor, is involved in NPFF secretion from the spinal cord. In view of the role of substance P (1-11) and substance P (1-7) in sensory transmission, the results of this study further support the role of NPFF in the modulation of antinociception in the spinal cord.

Distinct roles for the two cGATA-1 finger domains

We have generated and analyzed by functional assays mutations of the chicken erythroid transcription factor GATA-1. The cGATA-1 protein contains two related finger domains highly conserved across species and characteristic of the family of GATA-binding factors. We find that mutations in the C-terminal finger or adjacent basic region abolish sequence-specific DNA binding, confirming that this region constitutes a novel DNA-binding domain sufficient to recognize the consensus WGATAR motif. At least three separate regions outside of this finger II domain contribute in a cooperative manner to the trans-activation potential of the protein. As expected from previous results analyzing the mouse homolog, we find that the N-terminal finger plays a role in DNA binding by affecting the stability of the DNA-protein complex. In addition, we find mutations of finger I subtly altered in DNA-binding function which greatly diminish trans-activation. Our results support the notion that the GATA-1 protein must be positioned precisely on the GATA cis element to enable the activation of target genes.