Heteromultimeric complexes of CD40 ligand are present on the cell surface of human T lymphocytes

CD40 ligand (CD40L), a 33-kDa type II membrane glycoprotein expressed primarily on activated CD4+ T lymphocytes, is responsible for the helper function of T cells on resting B cells in a non-antigen-dependent, non-major histocompatability complex-restricted fashion. Interaction of CD40L with its receptor CD40 induces proliferation of and isotype switching in B lymphocytes. Recently we solved the x-ray structure of recombinant soluble CD40L and showed that, similar to other members of the tumor necrosis factor family, CD40L indeed exists as a trimer. We now report that, under normal physiological conditions, CD40L molecules exist as heteromultimeric complexes. These CD40L complexes, made of the full length and smaller fragments of CD40L, are present on the cell surface of T lymphocytes and are capable of interacting with CD40 molecule. A prominent fragment with a mass of 31 kDa accounts for as much as half of the CD40L on the surface of Jurkat cells. N-terminal sequence data revealed that this fragment lacks the cytoplasmic tail. A minor 18-kDa fragment of CD40L was also characterized which lacks the cytoplasmic tail, transmembrane region, and stalk region of the extracellular domain. The presence of CD40L heteromultimeric variants implies an additional regulation of the functional activity of this ligand complex.

Identification of HIV-1 determinants for replication in vivo

Pathogenic organisms are frequently attenuated after long-term culture in vitro. The mechanisms of the attenuation process are not clear, but probably involve mutations of functions required for replication and pathogenicity in vivo. To identify these functions, a direct comparison must be made between attenuated genomes and those that remain pathogenic in vivo. In this study, we used the heterochimeric SCID-hu Thy/Liv mouse as an in vivo model to define human immunodeficiency virus type 1 (HIV-1) determinants which are uniquely required for replication in vivo. The Lai/IIIB isolate and its associated infectious molecular clones (e.g., HXB2) were found to infect T cell lines but failed to replicate in the SCID-hu Thy/Liv model. When a lab worker was accidentally infected by Lai/IIIB, however, HIV-1 was isolated only from infection of primary PBMC, and not from infection of T cell lines. We hypothesized that the lab worker was exposed to a heterogeneous viral stock which had been attenuated by passage in immortalized T cell lines. Either a rare family member from this stock was selected for in vivo replication or, alternatively, an attenuated genotype dominant in vitro may have reverted to become more infectious in vivo. To address this hypothesis, we have used the SCID-hu Thy/Liv model to study the replication of HXB2 and of HXB2 recombinant viruses with HIV-1 fragments isolated from the infected lab worker. HXB2 showed no or very low levels of replication in the Thy/Liv organ. Replacement of its subgenomic fragment encoding the envelope gene with a corresponding fragment from the lab worker isolate generated a recombinant virus (HXB2/LW) which replicated actively in SCID-hu mice. The NEF mutation in the HXB2 genome is still present in HXB2/LW. Thus, the LW sequences encode HIV-1 determinants which enhance HIV replication in vivo in a NEF-independent mechanism. The specific determinants have been mapped to the V1-V3 regions of the HIV-1 genome. Six unique mutations in the V3 loop region of HXB2/LW have been identified which contribute to the increased replication in vivo.

Characterization of gpt deletion mutations in transgenic Chinese hamster cell lines

The transgenic cell lines G12 and G10, each with a bacterial gpt gene stably integrated at a single but different position in the Chinese hamster genome, were evaluated for deletion of the gpt transgene following exposures to several clastogens. More than 150 independently cloned G12 and G10 6-thioguanine-resistant mutants have been characterized by polymerase chain reaction (PCR) amplification and Southern blots in this study. Despite differences in the integration sites for the gpt gene in the G12 and G10 cells, PCR amplification of the gpt gene from both cell lines can be performed using the same single set of primers. By PCR deletion screening, about 20% of recovered spontaneous 6-thioguanine resistant (6TG) gpt G12 mutants had deleted the transgene, whereas the deletion mutant frequency was increased to about 50% of the X-ray- and bleomycin-induced G12 mutants. In contrast, both spontaneous and induced deletion frequencies are considerably higher for the G10 cell line. Among spontaneous G10 mutants, up to 50% have deleted the gpt transgene, whereas almost all of the X-ray- and bleomycin-induced G10 mutants have lost the integrated gene sequence. These results are discussed in the context of the transgene integration sites and the influences of the surrounding genome that may render certain genetic regions prone to deletion.

Replication across O6-methylguanine by human DNA polymerase beta in vitro. Insights into the futile cytotoxic repair and mutagenesis of O6-methylguanine

Replication in vivo across unrepaired O6-methylguanine (m6dG) lesions by mammalian DNA polymerase beta (pol beta) during short patch repair may contribute to the cytotoxicity and mutagenesis of m6dG. We have employed in vitro steady state kinetic analysis to investigate the replication of oligonucleotide templates containing site-specific m6dG by human pol beta. Our results show that m6dG is a strong but not absolute block to replication by pol beta. pol beta exhibits mixed kinetic discrimination during overall replication across dG and m6dG. pol beta preferentially inserts dTMP rather than dCMP opposite m6dG. However, pol beta extends from the dC-m6dG base pair more efficiently than from the dT-m6dG base pair. This is in strong contrast to other polymerases such as the exonuclease-deficient Klenow fragment of Escherichia coli DNA polymerase I (exo-KF) that preferentially extends dT-m6dG by a factor of 10 over dC-m6dG. When both insertion and extension are considered, pol beta has a 15-fold overall preference for incorporation of the mutagenic substrate dTTP rather than the nonmutagenic substrate dCTP during replication across m6dG. This suggests that pol beta, in concert with the T:G-specific thymine DNA glycosylase, may be intricately involved in the futile cytotoxic repair induced by m6dG. Our results also suggest that replication across m6dG by pol beta may contribute to m6dG-induced G --> A transition mutations.

Expression of cytokeratin messenger RNA versus protein in the normal mammary gland and in breast cancer

It is not known how tightly regulation of cytokeratin (CK) protein expression is correlated with transcriptional activity in breast cancer. The level of control of CK expression in the normal mammary gland and in breast cancer has been assessed by combining in situ hybridization with riboprobes, and with immunohistochemistry using monospecific antibodies. In normal mammary gland, luminal cells showed abundant hybridization with complementary RNA (cRNA) probes for CK7, CK8, CK18, and CK19. Proteins of these CKs were correspondingly distributed except for that of CK19, which showed a heterogeneous staining. In primary carcinomas, both messenger RNAs (mRNAs) and proteins of CK8 and CK18 were generally expressed to a degree similar to that of normal epithelia, but a lower level of mRNA and protein of CK18 was observed in metastatic carcinomas. Reduced expression of CK7 and CK14 was observed in all carcinomas, and the correlation between mRNA and protein for these two cytokeratins was unbalanced, whereas the expression of CK19 mRNA and the proportion of its protein-positive cells were increased. The results suggest that these major CKs in normal mammary gland epithelia are regulated at the transcriptional level except for CK19, which is partially under the posttranscriptional control. The alterations observed in breast cancer are not only reflected by the reduced or increased expression of individual cytokeratins, but characterized by partial loss of the normal regulation of cytokeratin expression.

Keratin 14 and 19 expression in normal, dysplastic and malignant oral epithelia. A study using in situ hybridization and immunohistochemistry

Specific mRNA and protein for two major keratins, K14 and K19, were investigated in normal, dysplastic and malignant oral epithelia by combined in situ hybridization and immunohistochemistry. In normal epithelia, K14 mRNA and protein were present almost exclusively in the basal layer of non-cornified, and in rete-processes of cornified, sites. Dysplastic epithelium showed irregular extension of the K14 transcript and protein into superficial cells. In squamous cell carcinoma (SCC), K14 transcript was abundant in most samples whilst in one poorly differentiated carcinoma mRNA but no protein was detected. K19 mRNA and its protein were present predominantly in basal cells of noncornified epithelium, whereas in cornified epithelium only mRNA was detected. In dysplasias, K19 transcript was detected in all specimens but its protein was absent in most cases. Even more variations of K19 expression were observed in SSC. These findings indicate differences in the control of expression of K14 and K19 in normal epithelia and show that regulation is further disturbed during dysplastic change and malignancy.

[The design of air purification system and its effect on surgical ICU]

It is very important to protect air-cross infection and improve air quality in surgical intensive care unit. In the design and effect of "local air condition and purification control system", air microbe colony counter was greatly reduced to 48/m3 (control area), and 105/m3 (uncontrol area), compared to 618/m3 (untreatment), P < 0.01. This system shows stable function, sterilization effect, low cost, and is useful to protect air pollution in surgical intensive care unit.

Positive effect of overexpressed protein-tyrosine phosphatase PTP1C on mitogen-activated signaling in 293 cells

PTP1C, an SH2 domain-containing protein-tyrosine phosphatase, is predominantly expressed in hematopoietic cells, in which it negatively regulates cellular signaling. However, this enzyme is also expressed in many non-hematopoietic cells. We demonstrate here that in non-hematopoietic 293 cells, overexpression of a catalytically inactive mutant of PTP1C strongly suppressed the stimulatory effects of the epidermal growth factor or serum on cell proliferation, early gene transcription, and DNA synthesis. Similarly, the phosphorylation of the mitogen-activated protein kinase and mitogen-activated protein kinase kinase activity was markedly inhibited by overexpression of mutant PTP1C. The inhibitory effect of mutant PTP1C was overcome by cotransfection with wild-type PTP1C, but not with the structurally related PTP2C. Furthermore, expression of the mutant phosphatase resulted in hyperphosphorylation on tyrosine of a 95-kDa protein that was co-immunoprecipitated with the mutant, but not with the wild-type protein. These results suggest that, unlike in hematopoietic cells, PTP1C in 293 cells plays a positive role in epidermal growth factor- or serum-activated mitogenesis. Thus, PTP1C participates in multiple signaling pathways, where the enzyme, depending on its target molecules, may function as either a positive or negative mediator.

Identification and characterization of three genes and two pseudogenes on chromosome 13

A study was conducted on the feasibility of isolating genes and pseudogenes that map to chromosome 13 by a hybridization-based approach using a 13-specific library and pools of repeat-free cDNA clones. Five pairs of cDNA and chromosome 13 genomic clones were identified and characterized. Partial or full-length sequence was derived from all cDNAs, and database searches were performed for putative gene identification. Partial sequence was also obtained from the chromosome 13 genomic clones for comparison with those of the hybridizing cDNAs. As a result of these analyses we identified three genes, a putative homologue of a porcine mRNA encoding an unidentified hepatic protein, a putative homologue of a yeast integral membrane protein, and a gene for a translationally controlled tumor protein, and two processed pseudogenes, ribosomal proteins L23a and S3a. The latter was formerly identified as the v-fos transformation effector gene, Fte-1, and recently cited as a possible candidate for the BRCA2 gene on chromosome 13. All genes and pseudogenes were localized to cytogenetic bands by in situ hybridization of metaphase chromosomes with probes derived from the chromosome 13 genomic clones.

Adverse effects of medications on urinary symptoms and flow rate: a community-based study

The relationship between urinary symptoms and medication use was investigated in a community-based cross-sectional study involving a random sample of 2115 men 40-79 years of age in Olmsted County, Minnesota. The American Urological Association Symptom Index (AUASI) was generated from a validated self-administered questionnaire. Medication use was assessed by in-person interviews. While 1087 men reported daily medication use, only 136 reported daily use of medications known to affect urinary function adversely, including antidepressants (42), antihistamines (23), and bronchodilators (43). Age-adjusted AUASI scores were higher in men reporting daily use of antidepressants, and the association persisted after additionally adjusting for the Depression and Anxiety subscales of the General Psychological Well-Being Scale (adjusted mean difference, 2.1; 95% confidence interval (CI), 0.5-3.6; p = 0.008). The adjusted AUASI was also higher among men who took antihistamines daily (adjusted mean difference, 2.3; 95% CI, 0.3-4.3; p = 0.03). Lower age-adjusted urinary flow rates occurred with antidepressants, but not with antihistamines or bronchodilators. Clinicians evaluating men for causes of voiding dysfunction in accordance with the Agency for Health Care Policy and Research practice guideline for the diagnosis and management of benign prostatic hyperplasia should be aware that daily use of antidepressants or antihistamines may be associated with AUASI scores that are two to three points higher than in men not taking these medications.

[A comparison of plasma amino acid concentrations between appropriate and small for gestational age fetuses]

OBJECTIVE

To investigate the role of amino acid played in pathogenesis of small for gestational age (SGA) fetuses.

METHODS

Plasma amino acids' concentrations (PAAC) of umbilical venous samples obtained by cordocentesis before labor or at cesarean section were measured in 30 cases of appropriate for gestational age (AGA) fetuses at different gestational age. PAAC of both mother and fetuses were measured and compared in 10 cases of SGA and 10 cases of AGA.

RESULTS

In cases of AGA, the PAAC in fetuses (3.11 +/- 0.41 mmol/L) were found to be higher than that in mothers. There were significant correlations between fetal and maternal PAAC. The total PAAC in mothers and fetuses, and its ratios were not changed with gestational age. In cases of SGA, essential amino acids' concentration (EAA), especially branch chain amino acid (BCAA) and lysine, decreased significantly. The feto-maternal ratios of EAA and BCAA were reduced significantly, whereas concentrations of EAA and BCAA in mothers did not change significantly.

CONCLUSIONS

The results indicated that placental function and maternal nutrient supplement were important factors for maintaining fetal growth and development. In AGA cases, relationship of PAAC between mothers and fetuses were kept in a stable balance. In SGA fetuses certain amino acid metabolic disturbances existed. The reduction of some PAAC was not due to their decrease in mothers.

Effects of total lymphoid irradiation on SIV-infected macaques

The identification of antiretroviral drugs that prevent, or delay for extended periods, progression of HIV-related disease has been of limited success. Because the number of HIV-infected people continues to increase, other therapeutic approaches must be tested. Using simian immunodeficiency virus (SIV)-infected macaques in a feasibility study, total lymphoid irradiation (TLI) was administered in fractionated doses to the supradiaphragmatic and then the infradiaphragmatic lymph nodes until a cumulative dose of 34.2 Gy was achieved in each field. During treatment and for more than 1 year of follow-up, the effects of TLI on various virological, hematological, and immunological parameters were evaluated and compared to those of similarly treated, uninfected macaques. Despite sustained low numbers of CD4+ lymphocytes (< 100/microliters blood) during treatment, TLI was well tolerated, did not result in intercurrent infections, and more importantly, induced a transient decrease in viral burden and did not exacerbate disease. Remarkably, this lack of disease progression and apparent containment of SIV replication were maintained despite persistent failure of PBMCs to respond to mitogen stimulation. Because SIV (and HIV) requires activated lymphocytes to replicate, failure of PBMCs to respond fully to stimuli may have contributed to restricting virus replication. This idea was supported by in vitro experiments in which infection of PBMCs before TLI produced higher levels of cell-free SIV than those obtained during or after TLI. Last, repopulation of peripheral blood and lymph nodes with lymphocytes paralleled that observed in uninfected control animals. The results indicate that (1) immunosuppression alone is not sufficient to induce progression to AIDS, (2) SIV infection does not undermine the ability of the immune system to regenerate new cells during the clinically latent phase, and (3) further evaluation of TLI or other immunosuppressive regimens as potential therapies for HIV disease is warranted.

Molecular structure of the halogenated anti-cancer drug iododoxorubicin complexed with d(TGTACA) and d(CGATCG)

4'-Deoxy-4'-iododoxorubicin, a halogenated anthracycline derivative, is an anticancer agent currently under Phase II clinical trials. In preclinical studies, it has demonstrated significantly reduced levels of cardiotoxicity compared to currently employed anthracyclines. It also has modified pharmacological properties resulting in an altered spectrum of experimental antitumor activity. The iodine atom at the 4' position of the sugar ring reduces the basicity and enhances the lipophilicity of this compound as compared to related anthracycline drugs. We report here single crystal X-ray diffraction studies of the complexes of 4'-deoxy-4'-iododoxorubicin with the hexanucleotide duplex sequences d(TGTACA) and d(CGATCG) at 1.6 and 1.5 A, respectively. The iodine substituent does not alter the geometry of intercalation as compared to previously solved anthracycline complexes, but appears to markedly affect the solvent environment of the structures. This could have consequences for the interaction of this drug with DNA and DNA binding proteins in cells.

[The effect of transforming growth factor-beta on collagen expression by human embryonic fibroblasts]

Transforming growth factor-beta (TGF-beta) is a cytokine with diverse biological activity. It can regulate the metabolic function of extracellular matrix (ECM) and play an important role in the development of pulmonary fibrosis. Collagen are major ECM components that are responsible for normal lung structure and function. Collagen accumulation is a major feature of pulmonary fibrosis. In order to study the mechanism of pulmonary fibrosis, we examined the effects of TGF-beta on the production, mRNA expression of type I collagen and type IV collagen by cultures of human embryonic lung fibroblasts. The results indicated that TGF-beta can induce collagen formation and type I collagen, type IV collagen mRNA expression without affecting cell proliferation. We concluded that TGF-beta plays a role in collagen accumulation of pulmonary fibrosis and the changes in collagen production appear to be mediated on collagen mRNA level.

Phosducin and PP33 are in vivo targets of PKA and type 1 or 2A phosphatases, regulators of cell elongation in teleost rod inner-outer segments

Teleost rod photoreceptors elongate in the light and shorten in darkness. We are investigating the role of cAMP-dependent protein kinase (PKA), phosphatases and target phosphoproteins in the regulation of photoreceptor cell shape. Preparations of rod fragments, consisting of the motile inner segment with attached photosensory outer segment (RIS-ROS), undergo light-stimulated elongation in culture. The PKA-selective inhibitor, H89, enhanced RIS-ROS elongation in both light and darkness, suggesting that elongation is associated with dephosphorylation of PKA substrates. Okadaic acid and calyculin A, inhibitors of type 1 and 2A phosphatases, blocked light-dependent and light-independent elongation with relative potencies suggesting that elongation requires dephosphorylation by type 1 phosphatase in light and type 2A phosphatase in darkness. To identify targets of PKA and phosphatases, RIS-ROS were isolated from retinas prelabeled with 32P-orthophosphate, and then incubated in the presence of kinase inhibitors or phosphatase inhibitors. Two phosphoproteins, PP33 and PP35, were phosphorylated by PKA and dephosphorylated by type 1 or 2A phosphatases in light- and dark-cultured RIS-ROS. PP35 (but not PP33) was immunoprecipitated by an antibody to phosducin, a PKA-regulated modulator of phototransduction (Lee et al., 1992); PP35 was also phosphorylated in vitro by a Ca2+ calmodulin-activated kinase. PP33 further differed from PP35 in its phosphopeptide maps and phosphorylation by PKC. We conclude that RIS-ROS elongation is correlated with the dephosphorylation of PKA substrates by type 1 or 2A phosphatases. Candidate mediator proteins include PP35, a fish phosducin homolog, and PP33, a newly described photoreceptor phosphoprotein.

Development of a human thymic organ culture model for the study of HIV pathogenesis

The development of effective therapies for the treatment of AIDS would be facilitated by a better understanding of HIV pathogenesis in vivo. While some aspects of pathogenesis may be assessed by standard tissue culture assays, in vivo animal models may provide clues to other aspects of HIV-mediated progression toward AIDS. Current animal models include primate models for the study of simian immunodeficiency virus (SIV) and HIV, SCID-hu and hu-PBL SCID mouse models for the study of HIV, and feline models for the study of feline immunodeficiency virus (FIV). In general these models are costly and labor intensive. We have developed a simple human fetal thymic organ culture (TOC) system that is permissive for HIV infection and that exhibits pathology similar to that observed in vivo. A key feature of this system is the time-dependent destruction of thymocytes typified by the preferential loss of CD4-expressing cells. HIV-mediated thymocyte destruction occurs by a process involving programmed cell death. We have infected TOC with a panel of HIV isolates and found that the resulting viral replicative and pathogenic profiles are similar to those seen in the SCID-hu Thy/Liv mouse, yet different from profiles observed in standard PHA-blast tissue culture assays. In addition, we find that TOC may be used to assess efficacy of antiviral agents such as AZT (3'-azido-3'-deoxythymidine) and ddI (2',3'-dideoxyinosine) in blocking both viral replication and virus-induced pathology. These results indicate that this model is amenable to the systematic manipulation, analysis, and characterization of a variety of HIV virus isolates and antiviral therapies.

Expression of antisense osteopontin RNA inhibits tumor promoter-induced neoplastic transformation of mouse JB6 epidermal cells

Elevated expression of osteopontin (OPN), a secreted adhesive phosphoglycoprotein, is frequently associated with many transformed cell lines of epithelial and stromal origin. Moreover, several clonal lines of preneoplastic JB6 cells derived from Balb/c mouse epidermal cultures (Colburn et al., 1978, 1979), upon treatment with 12-O-tetradecanoyl phorbol-13-acetate (TPA), become irreversibly oncogenic and concomitantly synthesize OPN at elevated levels (Smith and Denhardt, 1989). In the present study we sought to determine whether OPN expression facilitates transformation of such preneoplastic (initiated) cells. We transfected TPA-promotable JB6 c141.5a cells with an expression vector containing mouse OPN cDNA in antisense orientation under transcriptional control of dexamethasone-inducible MMTV-LTR promoter. Four stably transfected clones, which expressed drastically reduced levels of OPN in the presence of both dexamethasone and TPA, were characterized. We found that (a) more than 20 copies of OPN antisense cDNA were stably incorporated into the genome of cells from two of these clones that were examined by Southern blot analysis; (b) dexamethasone-induced expression of antisense OPN RNA prevented augmented OPN expression at both mRNA and protein levels following TPA treatment; and (c) cells from all four clones failed to form colonies in soft agar medium containing both dexamethasone and TPA. Taken together, these data demonstrate that inhibition of elevated OPN expression blocks TPA-induced anchorage-independent growth of JB6 c141.5a cells, suggesting the possibility that OPN overproduction is causally related to transformation of preneoplastic cells.

[Light microscope and energy dispersive X-ray analysis of amalgam pigmentation]

24 cases of amalgam pigmentation were analyzed by light microscope. 16 cases were amalgam debris, 8 cases were amalgam fragments and debris mixed. The amalgam distributed mainly along basement membrane of the epithelium, wall of blood vessels, nerve fibers, reticular fibers and endomysiums. In case where amalgam entered the bone, bone cells disappeared, lacuna emptied and microfracture of bony trabecullae occurred. In 8 cases pathologic calcification were found and in 18 cases there were inflammatory responses. 2 cases were analyzed by energy dispersive X-ray. It was found that in the different sites of tissues there were different content of Ag, Hg, Sn and Ca.

[Textual research on Newly Carved sun Zhenren's Qian jin fang]

As one of the ancient edition of Qian jin fang, this Newly Carved Sun Zhenren's Qian Jin Fang is far more authentic in the structure of its contents and its text, as compared to those editions of the Song Dynasty, and is, of course, closer to its original form and more reliable with textual significance. This article explores the distribution, characters of the edition and time of carving.

HIV-1-induced thymocyte depletion is associated with indirect cytopathogenicity and infection of progenitor cells in vivo

Direct and indirect cytopathic mechanisms have been proposed to account for the loss of CD4+ T cells after infection with human immunodeficiency virus type 1 (HIV-1). We report here that HIV-1 infection of the human thymus in vivo results in thymocyte depletion by at least two different mechanisms. Thymocytes within multiple stages of differentiation are induced to die of apoptosis; most of these cells are uninfected. Additionally, thymopoiesis is interrupted by direct infection and destruction of intrathymic CD3-CD4+CD8- progenitor cells. These mechanisms are differentially induced by distinct isolates of HIV-1.

Deletion analysis of protein kinase C inactivation by calphostin C

Protein kinase C (PKC) undergoes specific inactivation by nanomolar concentrations of calphostin C. Both PKC-alpha (a Ca(2+)-dependent conventional isoform) and PKC-epsilon (a Ca(2+)-independent novel isoform) are similarly inactivated by calphostin C (75-100 nM produced 50% inhibition), suggesting that inactivation requires a site common to both classes of PKC. We therefore performed studies to identify a critical region in the regulatory domain of PKC-alpha required for inactivation by calphostin C. A series of N-terminal-truncation mutants of bovine PKC-alpha expressed in Saccharomyces cerevisiae was tested with 500 nM calphostin C, a concentration sufficient to inactivate wild-type PKC-alpha by 80-90%. This concentration was as effective with mutant proteins containing deletions of up to 91 amino acid (aa) residues from the amino terminus (ND91), whereas a mutant protein truncated by 140 aa (ND140) was inactivated by only 20%. These findings imply that the aa sequence 92-140 is a structural determinant of PKC-alpha inactivation by calphostin C. This sequence contains one of the phorbol ester-binding sites (aa 102-144), which is highly conserved among most PKC isoforms including PKC-epsilon. In addition to aa 92-140, PKC-stimulating cofactors (phosphatidylserine, phorbol ester, and Ca2+) are required for inactivation by calphostin C even in the case of PKC mutants that do not require these cofactors for enzymatic activity. These results suggest that cofactors provide a template that is required for productive interaction of PKC and the inhibitor. The significance of the proposed proximity effect to calphostin C action is discussed.

Protein and mRNA expression of simple epithelial keratins in normal, dysplastic, and malignant oral epithelia

Simple epithelial keratins K7, K8, and K18 are present in no more than trace amounts in normal stratified squamous epithelial but have been reported in squamous cell carcinomas. With the aim of determining the level at which keratin synthesis is regulated in vivo, we have compared the expression of mRNA by in situ hybridization and protein by immunohistochemistry for K7, K8, and K18 in a series of normal, dysplastic, and malignant oral epithelia. In normal epithelia mRNAs for K7, K8, and K18 were present in basal and lower spinous cells but adjacent sections were generally negative for the respective proteins. In severe dysplasia there was irregular suprabasal extension of K8 and K18 mRNAs in all cases and their proteins were expressed in more than half of the cases. The carcinomas expressed K8 and K18 mRNAs homogeneously and were strongly reactive for these keratin proteins but K7 expression appeared reduced in malignancy. These results are consistent with the post-transcriptional regulation of K7, K8, and K18 expression in normal epithelia and the presence of their proteins in dysplastic and malignant epithelia suggests the release of these epithelial cells from a post-transcriptional block on K8 and K18 translation. Alternatively, rapid degradation of K8 and K18 protein might be occurring in normal epithelia but be suppressed in dysplasia and malignancy.

Rapid-high, syncytium-inducing isolates of human immunodeficiency virus type 1 induce cytopathicity in the human thymus of the SCID-hu mouse

Clinical deterioration in human immunodeficiency virus type 1 (HIV-1) disease is associated with an increased viral burden in the peripheral blood and a loss of circulating CD4+ T cells. HIV-1 isolates obtained prior to this stage of disease often have a "slow-low," non-syncytium-inducing (NSI) phenotype, whereas those obtained afterwards are often characterized as "rapid-high" and syncytium inducing (SI). Paired NSI and SI isolates from two different patients were inoculated into the human thymus implants of SCID-hu mice. The two slow-low, NSI isolates replicated to minimal levels in the grafts and did not induce thymocyte depletion. In contrast, the two SI isolates from the same patients showed high levels of viral replication and induced a marked degree of thymocyte depletion, accompanied by evidence of programmed cell death. These observations reveal a correlation between the replicative and cytopathic patterns of HIV-1 isolates in vitro and in the SCID-hu mouse in vivo and provide direct evidence that the biological phenotype of HIV-1 switch may be a causal and not a derivative correlate of HIV-1 disease progression.

Construction and characterization of a normalized cDNA library

We have developed a simple procedure based on reassociation kinetics that can reduce effectively the high variation in abundance among the clones of a cDNA library that represent individual mRNA species. For this normalization, we used as a model system a library of human infant brain cDNAs that were cloned directionally into a phagemid vector and, thus, could be easily converted into single-stranded circles. After controlled primer extension to synthesize a short complementary strand on each circular template, melting and reannealing of the partial duplexes at relatively low C0t, and hydroxyapatite column chromatography, unreassociated circles were recovered from the flow through fraction and electroporated into bacteria, to propagate a normalized library without a requirement for subcloning steps. An evaluation of the extent of normalization has indicated that, from an extreme range of abundance of 4 orders of magnitude in the original library, the frequency of occurrence of any clone examined in the normalized library was brought within the narrow range of only 1 order of magnitude.

Metal mutagenesis in transgenic Chinese hamster cell lines

Metals are toxic agents for which genotoxic effects are often difficult to demonstrate. To study metal mutagenesis, we have used two stable hprt/gpt+ transgenic cell lines that were derived from Chinese hamster V79 cells. Both the G12 and G10 cell lines are known to be very sensitive to clastogens such as X-rays and bleomycin, with the mutagenic response of the integrated xanthine guanine phosphoribosyl transferase (gpt) gene in G10 usually exceeding that of the same gene in the transgenic G12 cells. In studies with carcinogenic insoluble nickel compounds, a high level of mutagenesis was found at the gpt locus of G12 cells but not at the endogenous hypoxanthine phosphoribosyl transferase (hprt) locus of V79 cells. We have since demonstrated the similar recovery of a high frequency of viable G12 mutants with other insoluble nickel salts including nickel oxides (black and green). The relative mutant yield for the insoluble nickel compounds (G12 > G10) is the opposite of that obtained with nonmetal clastogens (G10 > G12). In the G12 cells, nickel mutagenesis may be related to the integration of the gpt sequence into a heterochromatic region of the genome. For some of the insoluble nickel compounds, significant inhibition of both cytotoxicity and mutant yield resulted when the G12 cells were pretreated with vitamin E. In comparison with the nickel studies, the mutagenic responses to chromium compounds in these cell lines were not as dramatic. Mutagenesis of the gpt target could not be demonstrated with other metals such as mercury or vanadium.

Selection of cDNAs using chromosome-specific genomic clones: application to human chromosome 13

We have developed a general method for en masse isolation of cDNAs present in a normalized library by hybridization to arrayed chromosome-specific phage lambda clones; we have used this approach to initiate exon-mapping of human chromosome 13. An advantage of the simultaneous isolation of cDNA/lambda pairs is that it allows cytogenetic assignment of a bona fide genomic clone by in situ hybridization, which also verifies that the corresponding cDNA or a homologous expressed sequence resides on chromosome 13. This information is enriched by partial sequencing of a selected cDNA from both ends. The sequence of the 3' noncoding region provides an 'identifier' that is used to develop STSs, while the sequence from the 5' end, often corresponding to a coding region, is used for homology searches in databases that occasionally reveal gene functions.

Ligand regulation of bovine protein kinase C alpha response via either cysteine-rich repeat of conserved region C1

Based on the finding by others that the conserved region C1 of conventional protein kinase C isoforms carries two independent, cysteine-rich phorbol ester binding sites, we have mapped the structural elements of the C1 region for their role in the phorbol ester- and phospholipid regulation of PKC alpha responses. We have prepared two amino terminal truncation mutants of bovine PKC alpha, ND91 lacking the first Cys-repeat of C1, and ND153 lacking both Cys-repeats of C1, as well as two internal deletion mutants, D162-245 lacking most of C2, and D109-263 lacking most of C2 and the second Cys-repeat of C1. The mutants were expressed in the yeast Saccharomyces cerevisiae which allows the rapid biochemical and physiological characterization of mammalian PKC isoforms. We found that all mutants displayed an elevated basal level of enzymatic activity in vitro but retained the basic catalytic PKC characteristics: regulation by Ca2+ and (except for ND153) by phospholipid or phorbol ester. In vivo we observed proportional physiological responses, the stimulation of Ca2+ uptake, and an increase in the cell doubling time for all mutants upon phorbol ester stimulation (constitutive for ND153) similar to the response of normal PKC alpha. Our findings indicate that after partial PKC activation by deletion mutagenesis, the presence of either Cys-repeat in C1 still allows phospholipid- and phorbol ester regulation of protein kinase C alpha responses.

Intermediate filaments in oral neoplasia. I. Oral cancer and epithelial dysplasia

The major value of intermediate filaments (IFs) in biological and applied research lies in their high order of cell and tissue specificity. This is particularly well illustrated in keratin (K) expression in various oral epithelia. Although the original class of IF is usually conserved in tissues after neoplastic transformation, epithelia show a tendency to shift their pattern of keratin expression in a manner which, while not predictable with precision, may sometimes be of diagnostic or prognostic significance. This review compares the keratins in normal oral epithelia, which show a mainly site-dependent expression, with those in squamous cell carcinoma. Key changes in the latter are the presence of simple epithelial keratins, K8 and K18 (occasional K7), reduced expression of differentiation-linked keratins (K1, K10, K4 and K13) and a tendency for down-regulation of primary keratins, K5 and K14. Moderate and severe dysplasias also tend to exhibit K8 and K18 with concomitant disordered expression of differentiation-linked keratins. There are reports of similar changes after neoplastic transformation in other mucosal sites and skin. Before this information can be applied diagnostically in immunocytochemical studies, the anti-keratin antibodies must be fully characterised and their interaction with the relevant tissue, both frozen and conventionally processed, should be evaluated.

Transgenic gpt+ V79 cell lines differ in their mutagenic response to clastogens

Several gpt+ transgenic cell lines were derived from hprt V79 cells to study mutagenesis mechanisms in mammalian cells. The G12 cell line was previously shown to be hypermutable by X-rays and UV at the gpt locus compared to the endogenous hprt gene of the parental V79 cells (Klein and Rossman, 1990), and is now shown to be highly mutable by the clastogenic anti-tumor agent bleomycin sulfate. A second transgenic cell line G10, which has a different gpt insertion site, was studied in comparison with G12. Both G12 and G10 cell lines carry the stable gpt locus at a single integration site in the Chinese hamster genome, and neither spontaneously deletes the integrated gpt sequence at a high frequency. Although spontaneous mutation to 6-thioguanine resistance in G10 cells is 3-4 times higher than in G12 cells, the cell lines differ to a much greater extent when mutated by clastogens. In comparison to G12 cells, the gpt locus in G10 cells is up to 13 times more sensitive to bleomycin mutagenesis and 5 times more responsive to X-ray mutagenesis. In contrast, there is much less difference in UV-induced mutagenesis and no differences in mutagenesis induced by alkylating agents such as N-methyl-N'-nitro-N-nitrosoguanidine (MNNG). The dose-dependent decrease in survival of the transgenic cells is the same for all mutagens tested, and does not differ from that of V79 cells. Neither transgenic cell line is generally hypermutable, since mutagenesis at an endogenous gene, Na+K+/ATPase, is similar to that of the parental V79 cell line. Although both cell lines can be induced to delete the transgene following clastogen exposure, deletions are not the only recovered mutations, and the cell lines can also be used to study mutations within the PCR recoverable gpt gene. The utility of these transgenic cells to investigate genome position effects related to mammalian mutagenesis mechanisms is discussed.

[Guanfu base A inhibit the post-infarction ventricular arrhythmias in dogs]

Harris tow-stage left anterior coronary ligation was performed in anesthetized dogs. After twenty hours, severe ventricular arrhythmias were recorded under conscious state. Cumulative intravenous injections of guanfu base A, a new alkaloid isolated from the tuber of Aconitum coreanum in China, from 10 to 40 mg.kg-1 produced remarkable antiarrhythmic effect lasting over 30 min and a moderate reduction of heart rate. The P-R interval, QRS complex and Q-T interval of the sinus rhythm were not significantly altered. The antiarrhythmic potency of guanfu base A in this model was found to be about one third that of quinidine.

Reconstitution of protein kinase C alpha function by the protein kinase C beta-I carboxy terminus

The Ca(2+)- and phospholipid-dependent Ser/Thr kinase protein kinase C (PKC) plays important roles in the transduction of cellular signals. Various PKC isoforms exist in mammalian cells which share conserved and variable regions as defined by cDNA sequence comparisons. To test whether carboxyl (C) terminal sequences of distinct isoforms can complement each other to yield functional chimeric molecules, we have constructed a PKC chimera in which amino acids 595-672 at the C-terminus of bovine PKC alpha (a) were replaced with the corresponding C-terminal amino acids (598-671) of rat PKC beta-I (b) to yield the chimera alpha/beta-I (ab). The chimera was then characterized biochemically and functionally, and compared with the parental isoforms. Since structure/function analysis of PKC in mammalian experimental systems is complicated by multiple PKC isoforms and by cellular complexity, we stably introduced the PKC constructs into the yeast Saccharomyces cerevisiae, a simple, lower eukaryote with a short doubling time and well established molecular genetics. In yeast, the faithfully expressed PKCab chimera and normal PKC isoforms bound radiolabelled phorbol ester and were recognized on immunoblots by PKC-specific antibodies. The chimera phosphorylated substrate peptides in a PMA- and Ca(2+)-dependent manner, and, upon activation, increased the cell doubling time and the rate of Ca2+ uptake into cells. In addition, PKCab displayed characteristics distinct from normal PKCb, but virtually indistinguishable from normal PKCa. Our findings indicate the reconstitution of PKCa function by the PKCb carboxyl terminus.

Expression of keratin mRNAs and proteins in normal salivary epithelia and pleomorphic adenomas

Control of keratin (K) gene expression may be important for cell differentiation in complex epithelia such as salivary gland. To investigate differences in distribution between keratin mRNAs and their respective proteins, a combined in situ hybridization (ISH) and immunohistochemical study was undertaken on nine normal salivary glands and seven pleomorphic adenomas. ISH employed riboprobes to K7, K8, K14, K18, and K19. Immunohistochemistry was performed on adjacent sections using monoclonal antibodies (MAbs) to the same keratins. Normal luminal cells showed abundant hybridization with probes for K7, K8, K18, and K19. Keratin 14 mRNA was present in basal and myoepithelial cells at a low level of expression. Proteins of their keratins were strongly stained. Neoplastic cells showed variable expression of mRNA and protein for K7, K8, K18, and K19. There was a high level of K14 mRNA but variable protein. The findings provide evidence that expression of these keratins in normal salivary epithelia is regulated transcriptionally and that in neoplasia this system is in considerable disarray.

Yeast phenotype classifies mammalian protein kinase C cDNA mutants

The phorbol ester receptor protein kinase C (PKC) gene family encodes essential mediators of eukaryotic cellular signals. Molecular dissection of their mechanisms of action has been limited in part by the lack of random mutagenesis approaches and by the complexity of signaling pathways in mammalian cells which involve multiple PKC isoforms. Here we present a rapid screen which permits the quantification of mammalian PKC activity phenotypically in the yeast Saccharomyces cerevisiae. Bovine PKC alpha cDNA is functionally expressed in S. cerevisiae. This results in a phorbol ester response: a fourfold increase in the cell doubling time and a substantial decrease in yeast colony size on agar plates. We have expressed pools of bovine PKC alpha cDNAs mutagenized by Bal 31 deletion of internal, amino-terminal, or carboxyl-terminal sequences and have identified three classes of mutants on the basis of their distinct yeast phenotypes. Representatives of each class were analyzed. An internal deletion of amino acids (aa) 172 to 225 displayed ligand-dependent but reduced catalytic activity, an amino-terminal truncation of aa 1 to 153 displayed elevated and ligand-independent activity, and a carboxyl-terminal 26-aa truncation (aa 647 to 672) lacked activity under any conditions. Additional mutations confirmed the distinct functional characteristics of these classes. Our data show that deletion of the V1 and C1 regions results in elevated basal catalytic activity which is still Ca2+ responsive. Internal deletions in the V2 and C2 regions do not abolish phorbol ester or Ca2+ regulation of PKC activity, suggesting that most of the C2 domain is not essential for phorbol ester stimulation and most of the regulatory domain is dispensable for Ca2+ regulation of PKC activity. These distinct activities od the PKC mutants correlate with a specific and proportional yeast phenotype and are quantified on agar plates by yeast colony size. This provides a phenotypic screen which is suitable to identity rare, randomly altered but active mammalian PKC mutants. It quantifies their catalytic and biological activities in response to PKC activators or inhibitors for a systematic mapping of PKC structure and function or PKC-drug interaction.

Phorbol ester activation of functional rat protein kinase C beta-1 causes phenotype in yeast

The phorbol ester receptor protein kinase C (PKC) gene family encodes essential mediators of various eukaryotic cellular signals. The molecular dissection of its mechanisms of action has been limited in part by the genetic inaccessibility and complexity of signaling in mammalian cells. Here we present a novel approach to study rat PKC beta-1 action in yeast, a simple lower eukaryotic genetic model. Expression of its cDNA in Saccharomyces cerevisiae introduces novel phorbol ester binding sites which stimulate a specific calcium- and phospholipid-dependent catalytic activity in vitro consistent with a fully functional protein which phosphorylates cellular yeast proteins in vivo. Phorbol ester activation of PKC beta-1 in vivo results in biological responses which include stimulation of extracellular calcium uptake, changes in cell morphology, and an increase in the cell doubling time. These PKC functions are not affected by truncation of 12 amino terminal amino acids; however, they are completely abolished by truncation of 15 or more carboxyl terminal amino acids which likely result in inactivation of the kinase. The increase in the yeast doubling time caused by PKC beta-1 activation provides a phenotype which can be exploited as a screen for the activity of random PKC cDNA mutations. Our findings indicate that rat PKC beta-1 is functional in yeast and leads to biological responses which suggest compatible aspects of higher and lower eukaryotic signaling pathways and the feasibility of dissecting parts of the action of common signaling mediators in a simple genetic model.

LYAR, a novel nucleolar protein with zinc finger DNA-binding motifs, is involved in cell growth regulation

A cDNA encoding a novel zinc finger protein has been isolated from a mouse T-cell leukemia line on the basis of its expression of a Ly-1 epitope in a lambda gt11 library. The putative gene was mapped on mouse chromosome 1, closely linked to Idh-1, but not linked to the Ly-1 (CD5) gene. The cDNA is therefore named Ly-1 antibody reactive clone (LYAR). The putative polypeptide encoded by the cDNA consists of 388 amino acids with a zinc finger motif and three copies of nuclear localization signals. Antibodies raised against a LYAR fusion protein reacted with a protein of 45 kD on Western blots and by immunoprecipitation. Immunolocalization indicated that LYAR was present predominantly in the nucleoli. The LYAR mRNA was not detected in brain, thymus, bone marrow, liver, heart, and muscle. Low levels of LYAR mRNA were detected in kidney and spleen. However, the LYAR gene was expressed at very high levels in immature spermatocytes in testis. The LYAR mRNA is present at high levels in early embryos and preferentially in fetal liver and fetal thymus. A number of B- and T-cell leukemic lines expressed LYAR at high levels, although it was not detectable in bone marrow and thymus. During radiation-induced T-cell leukemogenesis, high levels of LYAR were expressed in preleukemic thymocytes and in acute T leukemia cells. Fibroblast cells overexpressing the LYAR cDNA from a retrovirus vector, though not phenotypically transformed in vitro, had increased ability to form tumors in nu/nu mice. Therefore, LYAR may function as a novel nucleolar oncoprotein to regulate cell growth.

Expression of keratin 14 and 19 mRNA and protein in normal oral epithelia, hairy leukoplakia, tongue biting and white sponge nevus

This study was undertaken to analyze keratin gene expression at both the mRNA and protein level in oral hairy leukoplakia (OHL). Comparisons were made with normal lingual epithelium from a similar site, tongue biting, normal buccal mucosa and another condition which disturbs oral epithelial differentiation, white sponge nevus. Combined immunocytochemical and in situ hybridization studies for keratins 14 and 19 were carried out on 2 specimens of OHL from HIV-positive males and one sample each of the other cases. Keratin 14 protein expression was uniform throughout all the epithelia. In normal epithelia and in lesions other than OHL, keratin 14 mRNA was most strongly expressed in basal cells with weaker but still significant amounts in the spinous cell layer. In both cases of OHL there was weaker basal cell expression of keratin 14 mRNA and frequent absence in koilocytoid cells. Keratin 19 protein expression was heterogeneous in the basal layer of all specimens with suprabasal staining of occasional groups of cells. Its mRNA was uniformly distributed in all cases. The findings indicate the keratin mRNA expression does not always parallel that of protein and that, in the case of keratin 14, expression may be influenced by the presence of EBV.

[Assay of negative inotropism of bepridil on isolated guinea pig left atrial myocardium by simulating constant rate of absorption and elimination]

The pharmacodynamic characteristic of negative inotropic effect of bepridil on isolated guinea pig cardiac atrium was conducted by gradient perfusion with constant rate of bepridil ranging from 0-20 mumol.L-1 and inverse, simulating a fixed pharmacokinetic parameters of K(a) and K(e), respectively. A counter-clockwise hysteresis loop of negative inotropism of bepridil was presented. Fixing Cp, T, and E by pharmacokinetics/pharmacodynamics (PK/PD) non-parameter model, the hysteresis loop was collapsed in figure plotting C(e) against E. The estimated K(eo) = 0.03 +/- 0.023 h-1, an apparent T1/2 of pharmacological effect was measured, and about 80-fold as long as the pharmacokinetic T1/2. It was suggested that the long-lasting effect of bepridil was partly due to the slow elimination rate from the effect compartment.

Stimulation of calcium uptake in Saccharomyces cerevisiae by bovine protein kinase C alpha

Ca2+ plays essential roles as a second messenger often in synergism with the calcium- and phospholipid-dependent phorbol ester receptor, protein kinase C (PKC), which stimulates Ca2+ influx in various cell types in a potential positive feedback mechanism. To address the compatibility of these mechanisms between lower eukaryotes and mammals, we have stably expressed bovine PKC alpha in the yeast Saccharomyces cerevisiae. We find that phorbol ester binding sites are created which stimulate a specific calcium- and phospholipid-dependent catalytic activity in vitro. Phorbol ester activation in vivo stimulates PKC down-regulation, uptake of extracellular Ca2+, Ca2+ dependence of cell viability, and changes in cell morphology. This may represent activation of a putative PKC-mediated signaling pathway utilized by functional yeast homologs of mammalian PKC isoforms. These are suggested by some protein data; however, their genes have not yet been characterized (Simon, A. J., Milner, Y., Saville, S. P., Dvir, A., Mochly-Rosen, D., and Orr, E. (1991) Proc. R. Soc. Lond. B 243, 165-171). Our findings indicate that bovine PKC alpha is functional in yeast and stimulates calcium uptake in a manner similar to some of its responses in mammalian cells, which suggests compatible aspects of higher and lower eukaryotic signaling pathways and the feasibility of dissecting parts of the action of common signaling mediators in a simple genetic model.

Genomic organization of the mouse granzyme A gene. Two mRNAs encode the same mature granzyme A with different leader peptides

Granzyme A is a serine protease that, together with the other granular components of cytotoxic T lymphocyte (CTL) cells, has been implicated in the cytolysis process. We report here two different messages and the genomic organization of the mouse granzyme A gene. The granzyme A gene is composed of six exons spanning 7 kilobases. Alternative splicing of the second exon results in the two transcripts. The two mRNA species encode the same mature granzyme A protein but with different leader sequences. The first (HF1) encodes a typical leader signal sequence similar to other granzymes, but the second (HF2) putative leader sequence is different and less hydrophobic. Both messages are present in cultured CTL cell lines and in normal lymphoid tissues. They are both induced when CTL cells are activated in vitro or in vivo. Both messages can be translated in vitro, although the HF1 message appears to be much more efficient as a template. The putative 5' promoter region of the HF gene sequenced (500 base pairs of upstream sequences) contains no well defined promoter sequences aside from the TATA box. The results suggest that (a) granzyme A may be produced with putative different leader sequences from two different mRNAs; (b) this may provide a model system for studying alternate splicing and the evolution of a complex enzymatic system in an organelle; and (c) the genomic DNA reported will be useful for studying transcription regulations involved in controlling the specific expression pattern of this gene.

Cytotoxicity with target DNA breakdown by rat basophilic leukemia cells expressing both cytolysin and granzyme A

The noncytotoxic rat mast cell tumor line RBL was transfected with genes for the cytotoxic lymphocyte granule proteins cytolysin (perforin) and granzyme A, giving transfectants with mRNA and protein expression levels comparable with cloned cytotoxic T lymphocytes. Both RBL-cytolysin and RBL-cytolysin-granzyme A transfectants showed extremely potent killing of red cell targets and lysed 20%-60% of EL4 lymphoma targets at an effector-to-target ratio of 30. RBL transfectants expressing only granzyme A were not cytotoxic. Significant EL4 DNA breakdown accompanying lysis was observed only with RBL that was transfected with both cytolysin and granzyme A. These results support the granule-exocytosis model for lymphocyte cytotoxicity and show that effector granzyme A plays a role in target cell DNA breakdown.

Three rapid immunoassays for the determination of creatine kinase MB: an analytical, clinical, and interpretive evaluation

We present analytical and clinical studies of three commercial immunoassays for the determination of the creatine kinase MB isoenzyme (CK-MB). All methods are compared with the presently-accepted reference method, agarose gel electrophoresis. We find that each of the immunoassay methods offers diagnostic sensitivity and specificity similar to those of electrophoresis, while none experiences detectable interference from high concentrations of the creatine kinase BB isoenzyme (CK-BB) or the so-called "atypical" bands. The presence of atypical bands can cause electrophoresis to yield inaccurate quantification or even misidentification of CK-MB. Because the immunoassay approaches are more rapid than electrophoresis and require less technical expertise, it is possible to evaluate patients in a more timely and cost-effective manner. Further, since immunoassay results can be available in approximately 1/2 hour, rapid real-time decisions can be made regarding the desirability of initiating or continuing such valuable but dangerous procedures as thrombolytic therapy.

[Effect of alcohol-extract from scorpion on checking externally active cysticerus cellulosae]

Putting the alcohol-extract from scorpion in the ordinary aqueous solution of 15% pork bile and having it cultured at the temperature of 37 degrees C have proved for the first time that in contrast with the chemical albendazole, Scorpion has a conspicuous effect on the external killing of the cysticercus cellulosae, The action of killing cysticercus cellulosae has almost nothing to do with the difference of processed products or of the parts used in medicine.

Herpes simplex virus alpha protein ICP27 can inhibit or augment viral gene transactivation

Three of the five alpha (immediate early) gene products of herpes simplex virus, infected cell proteins (ICPs) 4, 0, and 27 play a role in the control of expression of viral beta (delayed-early) and gamma (late) genes. We report here that ICP27 can inhibit or augment the individual or combined abilities of ICP4 and ICP0 to stimulate expression of chimeric genes containing viral gene promoters in a transient expression system. The specific effect of ICP27 was dependent on the viral gene promoter in the chimeric gene. ICP27 inhibited the ability of ICP4 and ICP0 to activate some beta gene promoters but augmented their ability to activate other beta or gamma 1 gene promoters when they were used in the target genes. Activation of the target genes by adenovirus E1A was not affected by ICP27 under the same conditions. ICP27 also repressed the ability of ICP0 to stimulate expression of a chimeric gene containing an alpha gene promoter. Insertion of a termination codon in the middle of the ICP27 coding region severely reduced the inhibitory effect of the plasmid, indicating that this activity requires expression of functional ICP27 polypeptide. This report focuses on the ICP27 activity that negatively regulates ICP4 transactivation of a chimeric gene containing the upstream sequences of the HSV beta gene ICP8. ICP27 decreased the level of mRNA initiated at the transcriptional start site of the ICP8 gene. The level of expression of the ICP4 gene was not changed by ICP27 but an alteration in the electrophoretic mobility of ICP4 expressed was observed. The modulatory effect of ICP27 on HSV transactivators may control the progress of the lytic cycle or provide a balance that varies in different cell types to affect whether lytic or latent infection ensues.

Immunopathological study on human cartilage allografts

The fate of human cartilage allografts and the mechanism of its kinetical development were studied histopathologically and immunohistologically. After transplantation, the grafts underwent necrosis, calcification and were partially invaded by osteoplastic tissue of the host and eventually replaced by bone tissue. Thus, the contour of the transplanted cartilage was kept partially by the living cartilage and the newly-formed osseous tissue. The grafts were surrounded initially by granular tissue and then by scar tissue, in which numerous T cells and a few macrophage infiltrates were noted. In T cells, T4+ lymphocytes predominated but T8+ cells accounted for a small number. B cells were not found within the infiltrates. Most of the infiltrating cells expressed 12 antigens, indicating that the majority of T cells were activated. It was concluded that T lymphocytes mediated cellular immunity played an important role. The chondrocytes of the cartilage did not express HLA I and II antigens before transplantation, but one month later, the living chondrocytes became HLA I and II antigens positive, and the antigen expression became stronger with the elapse of time; this might be induced by lymphokins, especially by interferon produced by the infiltrating lymphocytes. Such an expression of MHC antigens on chondrocytes might contribute to the further enhancement of immunorejection.