Increased blood flow resistance in placental circulation and levels of plasminogen activator inhibitors types 1 and 2 in severe preeclampsia

To study whether increased resistance in the placental circulation changes the plasma levels of plasminogen activators types 1 and 2 (PAI-1 and PAI-2) in severe preeclampsia, the levels of PAI-1 activity and PAI-2 antigen were determined in 33 severely preeclamptic and 22 normal pregnant women during gestational weeks 24-35. In the preeclampsia group, the Pulsatility Index (PI) of the umbilical artery was investigated with Doppler ultrasound. The levels of PAI-1 activity were higher (P < 0.01) whereas those of PAI-2 antigen were lower (P < 0.01) in the preeclampsia group than in the normal pregnancy group. The patients with abnormally high PI (high PI group) had increased PAI-1 levels (P < 0.05) and unchanged PAI-2 levels (P > 0.05), compared with those with normal PI (normal PI group). The levels of PAI-1 were positively correlated to the PI values during pregnancy weeks 34-35 only in the high PI group (r = 0.88, P < 0.05). In conclusion, high resistance in the placental circulation elevates plasma PAI-1 activity levels but does not influence PAI-2 antigen levels.

Anthelmintic activity of papaya latex against patent Heligmosomoides polygyrus infections in mice

The purpose of this experiment was to study the possible anthelmintic activity of papaya latex (Carica papaya) against Heligmosomoides polygyrus in experimentally infected mice. Five groups of BALB/C mice were infected with 100 Heligmosomoides polygyrus infective larvae/mouse. After patency (day 22) four groups of mice (groups B, C, D and E) were given papaya latex suspended in water at dose levels of 2, 4, 6 and 8 g of papaya latex/kg body weight, respectively. One group of mice (group A) served as non-treated controls. All animals were necropsied on day 25, i.e. 3 days after treatment, for post-mortem worm counts. The papaya latex showed an antiparasitic efficacy of 55.5, 60.3, 67.9 and 84.5% in groups B, C, D and E, respectively. The results may suggest a potential role of papaya latex as an anthelmintic against patent intestinal nematodes of mammalian hosts.

[Medicinal plant resources of Berberis L. in Guizhou province]

Based on field investigation and identification of 19 species and one variety of medicinal plant of Berberis produced in Guizhou Province, it has been found out that among these species 3 is found to be new ,4 species and one variety are discovered for the first time in Guizhou province. Geographical distribution, perpendicular distribution and medicinal uses of these species are spelled out and a key for their identification is given.

Local-level and global-level form characteristics in apparent-motion correspondence

This study addressed the "correspondence" problem of apparent-motion (AM) perception in which parts of a scene must be matched with counterparts separated in time and space. Given evidence that AM correspondence can be mediated by two distinct processes--one based on a low-level motion-detection mechanism (the Reichardt process), the other involving the tracking of objects by visual attention (the attention-based process)--the present study explored how these processes interact in the perception of apparent motion between hierarchically structured figures. In three experiments, hierarchical figures were presented in a competition motion display so that, across frames, figures were identical at either the local or the global level. In experiment 1 it was shown that AM occurred between locally identical figures. Furthermore, with the Reichardt AM component eliminated in experiments 3 and 4, no preference was obtained for either level. While evidence from previous studies that form extraction for hierarchically structured figures proceeds from the global to the local levels, the present results indicate the irrelevance of such a global precedence in AM correspondence. In addition, it is suggested that Reichardt AM correspondence between local elements constrains attention-based AM correspondence between global figures so that both components move in the same direction. It is argued that this constraining process represents an elegant means of achieving AM correspondence between objects undergoing complex transformation.

Cloning and structural analysis of the gene for cAMP-dependent protein kinase catalytic subunit from Plasmodium yoelii

We isolated the gene encoding the cAMP-dependent protein kinase catalytic subunit (cAPK[C]) from Plasmodium yoelii by screening a genomic library for the DNA fragment as produced by the polymerase chain reaction. The deduced protein of 341 amino acids conserves residues that are important for the function of serine/threonine protein kinases and shows the highest homology to cAPK[C]s of other organisms. However, P. yoelii cAPK[C] has 8 residues, which are perfectly conserved in cAPK[C]s of other organisms, radically replaced with residues having different side-chain properties. It is stressed that two radical replacements occur in regions for the binding with a regulatory subunit and/or a heat-stable inhibitor protein.

[Cultured human retinal pigment epithelial cell produced and secreted epidermal growth factor: its bioactivity and clinical significance]

The epidermal growth factor bioactivity from cultured primary human and monkey retinal pigment epithelial (RPE) cell systems was detected by using the radioreceptor assay. We report that the cultured human and monkey RPE cells produce and secrete the EGF bioactively to the media as demonstrated by radioreceptor binding assay. The EGF bioactivities secreted by human and monkey RPE cells were at peak of 48 hours (human RPE cells secreted 2.11 +/- 0.46 ng/ml vs monkey RPE was 1.56 +/- 0.12 ng/ml) in the serum-free media. The results indicate that the RPE is one of important sources for EGF in the eye. The RPE cells may play much important roles in the development of proliferative retinal diseases through the autocrine or paracrine mechanism. This new discovery will be helpful to elucidate the pathogenesis of proliferative retinal diseases and also provide an important basis for the treatment of such diseases.

Systolic anterior motion of the mitral valve in hypertrophic cardiomyopathy: an in vitro pulsatile flow study

Hypertrophic cardiomyopathy, or HCM, is a relatively common disease which results in the hospitalization of more than 13,000 patients every year. It is characterized by a thickening of the interventricular septum and by systolic anterior motion, or SAM, of the mitral valve, which occurs when the distal tip of the mitral leaflets contacts the hypertrophied septum during systole and obstructs the left ventricular outflow tract. Using an in vitro pulsatile flow model of the left ventricle, the objective of the study was to investigate the relationship between the ventricular flow field and the mechanism of SAM and to specifically address the hypothesis that papillary muscle displacement can alter left ventricular flow patterns and create drag forces that can initiate SAM. Flow visualization revealed the presence in the ventricle of a large organized recirculation region throughout diastole. Besides maintaining the mitral leaflets close to the posterior wall, normally positioned papillary muscles also caused the diastolic vortex to help the mitral valve close near the posterior wall while simultaneously prepositioning the upcoming systolic outflow stream close to the septum, thereby minimizing the flow forces acting on the mitral valve. In contrast, the anterior displacement of the papillary muscles moves the entire mitral apparatus into the outflow tract. It also reverses the direction of the recirculating diastolic flows: The diastolic vortex now promotes the initiation of SAM by displacing the closing mitral leaflets anteriorly and by positioning the systolic outflow stream close to the posterior wall. These events lead to the creation of form drag forces as the systolic flow impacts the posterior side of the mitral leaflets, initiating SAM.

Mechanism of active transcriptional repression by the retinoblastoma protein

The retinoblastoma tumour-suppressor protein (Rb) belongs to a family that share a motif known as the pocket. The pocket was originally identified as the region of Rb required for binding to oncoproteins from DNA tumour viruses, which disrupt the binding of Rb to the E2F family of cell-cycle transcription factors (referred to collectively here as E2F). Rb switches E2F sites from positive to negative elements, suggesting that Rb-E2F is an active complex that blocks transcription. Here we report that Rb is selectively recruited to promoters through E2F, where it in turn inactivates surrounding transcription factors by blocking their interaction with the basal transcription complex. We suggest that this repressor activity is essential for inhibiting promoters that contain enhancers in addition to E2F sites.

SV40-immortalized and primary cultured human retinal pigment epithelial cells share similar patterns of cytokine-receptor expression and cytokine responsiveness

Retinal pigment epithelial (RPE) cells produce and respond to a variety of cytokines; however, molecular and biochemical studies are restricted by the limited access to large numbers of pure cells and the variability associated with different donor sources. Despite success in establishing primary human RPE (HRPE) cell cultures, the inability to sustain consistent proliferation rates and morphology over several passages remains a concern. This problem was approached by using an immortalized line of simian virus (SV)40 transformed fetal HRPE cells (SVRPE). Cytokine production, receptor expression and responsiveness in the SVRPE cell line was analyzed to determine the usefulness of this model for studying HRPE-cytokine interactions. Using reverse transcriptase polymerase chain reaction (RT-PCR), HRPE and SVRPE cells demonstrated an identical pattern of interleukin-1 receptor (IL-1R), IL-2R (alpha sub-unit), IL-6R, interferon (IFN)-gamma R and tumor necrosis factor-alpha (TNF)R p55 expression. No amplification products for TNFR p75 or granulocyte/macrophage colony stimulating factor (GM-CSF)R were demonstrated in either population. IFN-gamma stimulation induced surface human leukocyte antigen (HLA)-DR in both SVRPE and HRPE, while TNF treatment induced surface expression of intercellular adhesion molecule (ICAM)-1 on SVRPE and upregulated ICAM from basal levels on HRPE. Both cell types showed amplification products for interleukin (IL)-1 beta, IL-6 and transforming growth factor (TGF)-beta 1 using RT-PCR. The bioassays demonstrated that both populations of unstimulated cells constitutively secrete very low levels of TGF-beta and no IL-6.(ABSTRACT TRUNCATED AT 250 WORDS)

Pollen fertility restoration by nuclear gene Fr in CMS common bean: an Fr linkage map and the mode of Fr action

The Fr gene in common bean, Phaseolus vulgaris L., is a unique gene for the study of plant nuclear-mitochondrial interactions because it appears to directly influence plant mitochondrial genome structure, resulting in the restoration of pollen fertility in cytoplasmic male sterile plants. This gene action is distinct from other pollen fertility restoration systems characterized to date. As a first step towards the map-based cloning of this unusual nuclear gene, we identified RAPD markers linked to Fr using bulked segregant analysis of near-isogenic lines. Using DNA gel blot hybridization, we localized the identified RAPD markers to a linkage group on the common bean RFLP map and constructed a linkage map of the Fr region using both RAPD markers and RFLP markers. Analysis of the mode of Fr action with the aid of identified Fr-linked DNA markers indicated that Fr functions in a semidominant fashion, showing dosage effect in controlling the dynamics of a heteroplasmic mitochondrial population. We also present our observations on the developmental distinctions, crucial in the accurate mapping of the Fr gene, between spontaneous cytoplasmic reversion and Fr-driven fertility restoration, two phenomena that are phenotypically indistinguishable.

[A study on expression of epidermal growth factor receptor in pleomorphic adenoma of lacrimal gland]

Expression of epidermal growth factor (EGF) receptor was examined in 32 cases of pleomorphic adenoma of lacrimal gland by means of an immunohistochemical method. While normal lacrimal glands were all negative for the antigen, EGF receptor was positive in 10 pleomorphic adenomas and the positive staining was mainly limited in the tumor cells in trabecular or duct-like arrangement or squamous metaplastic epithelium. These data suggest that the expression of EGF receptor be significantly higher in pleomorphic adenoma than in normal lacrimal gland, and also suggest that EGF receptor be expressed in the neoplastic cells which are considered to be of duct origin.

[Preliminary studies on protective effects of selenium on human fetal hepatocyte in vitro injured by lipid peroxidation]

A selenium protection model of human fetal hepatocyte in vitro injured by lipid peroxidation was established. It was found that survival rate and secretion of albumin of the injured cells decreased, and release of alanine transaminase (ALT) and its activities in the cells increased, as compared with those in controls, with a very significant difference. Under electronic microscope, ultrastructure of the injured cells appeared obscure, their membrane and membranous organella swelling, or membranous structure breaking. Injuries mentioned above in cells pre-treated with selenium were obviously decreased and activities of glutathione peroxidase increased. But protective effects of selenium supplement were weaker. It suggested that preventive supplement with selenium could reduce injury to human hepatocyte caused by lipid peroxidation.

Neutrophils from human immunodeficiency virus (HIV)-seronegative donors induce HIV replication from HIV-infected patients' mononuclear cells and cell lines: an in vitro model of HIV transmission facilitated by Chlamydia trachomatis

Infection with a sexually transmitted disease (STD) increases the risk for human immunodeficiency virus (HIV) infection. Polymorphonuclear leukocytes (PMNs) are recruited into the genital tract by STD pathogens, such as Chlamydia trachomatis. Semen of HIV-infected men contains HIV associated with mononuclear cells. This study investigated the interaction among PMNs from HIV-uninfected persons, C. trachomatis, and HIV-infected cells and examined the mechanisms for enhanced HIV replication. We demonstrated that PMNs from HIV-seronegative donors induced HIV replication in mononuclear cells from 17 HIV-infected patients in medium without exogenous IL-2. HIV in the cell-free supernatants from cocultures of PMNs and patients' peripheral blood mononuclear cells (PBMCs) was replication competent, as indicated by their capacity to propagate HIV in a second round of culture using PBMCs from HIV-seronegative individuals and by the fact that proviral DNA was found in these cells. PMNs from HIV-seronegative donors increased HIV replication over 100-fold in chronically HIV-infected cell lines of the monocytic, T, and B cell lineages. Moreover, PMNs increased U1 cells' production of p24 antigen by as much as ninefold when compared with U1 cells cocultured with PBMCs. The addition of C. trachomatis to PMN and U1 coculture increased HIV replication by an additional ninefold at 24 h, whereas C. trachomatis alone had no effect on p24 antigen production by U1 cells. Thus, C. trachomatis serves not only to recruit PMNs, but also to interact with PMNs to increase HIV replication. HIV replication is triggered by contact of HIV-infected cells with PMNs, by the generation of reactive oxygen intermediates (ROIs), and by soluble factors such as TNF-alpha and IL-6. This is based on the findings that production of p24 antigen, IL-6, and TNF-alpha induced by PMNs is abrogated by disrupting or partitioning PMNs from HIV-infected cells; is inhibited by superoxide dismutase and catalase, enzymes that destroy ROIs; is enhanced by differentiated HL60 cells capable of producing ROIs; and is induced by PMNs tested negative for CMV. Furthermore, the production of ROIs is independent of HIV infection of mononuclear cells, since PMNs cocultured with HIV-uninfected parental monocytic and T cell lines generated ROIs. Therefore, the increased risk for acquiring HIV infection associated with chlamydia cervicitis may be related to the local recruitment of PMNs by C. trachomatis and the induction of infectious virus from mononuclear cells present in semen. These observations provide a rationale for strategies to reduce HIV transmission by control of STD.

Neutrophils from human immunodeficiency virus (HIV)-seronegative donors induce HIV replication from HIV-infected patients' mononuclear cells and cell lines: an in vitro model of HIV transmission facilitated by Chlamydia trachomatis

Infection with a sexually transmitted disease (STD) increases the risk for human immunodeficiency virus (HIV) infection. Polymorphonuclear leukocytes (PMNs) are recruited into the genital tract by STD pathogens, such as Chlamydia trachomatis. Semen of HIV-infected men contains HIV associated with mononuclear cells. This study investigated the interaction among PMNs from HIV-uninfected persons, C. trachomatis, and HIV-infected cells and examined the mechanisms for enhanced HIV replication. We demonstrated that PMNs from HIV-seronegative donors induced HIV replication in mononuclear cells from 17 HIV-infected patients in medium without exogenous IL-2. HIV in the cell-free supernatants from cocultures of PMNs and patients' peripheral blood mononuclear cells (PBMCs) was replication competent, as indicated by their capacity to propagate HIV in a second round of culture using PBMCs from HIV-seronegative individuals and by the fact that proviral DNA was found in these cells. PMNs from HIV-seronegative donors increased HIV replication over 100-fold in chronically HIV-infected cell lines of the monocytic, T, and B cell lineages. Moreover, PMNs increased U1 cells' production of p24 antigen by as much as ninefold when compared with U1 cells cocultured with PBMCs. The addition of C. trachomatis to PMN and U1 coculture increased HIV replication by an additional ninefold at 24 h, whereas C. trachomatis alone had no effect on p24 antigen production by U1 cells. Thus, C. trachomatis serves not only to recruit PMNs, but also to interact with PMNs to increase HIV replication. HIV replication is triggered by contact of HIV-infected cells with PMNs, by the generation of reactive oxygen intermediates (ROIs), and by soluble factors such as TNF-alpha and IL-6. This is based on the findings that production of p24 antigen, IL-6, and TNF-alpha induced by PMNs is abrogated by disrupting or partitioning PMNs from HIV-infected cells; is inhibited by superoxide dismutase and catalase, enzymes that destroy ROIs; is enhanced by differentiated HL60 cells capable of producing ROIs; and is induced by PMNs tested negative for CMV. Furthermore, the production of ROIs is independent of HIV infection of mononuclear cells, since PMNs cocultured with HIV-uninfected parental monocytic and T cell lines generated ROIs. Therefore, the increased risk for acquiring HIV infection associated with chlamydia cervicitis may be related to the local recruitment of PMNs by C. trachomatis and the induction of infectious virus from mononuclear cells present in semen. These observations provide a rationale for strategies to reduce HIV transmission by control of STD.

Pollen fertility restoration by nuclear gene Fr in CMS bean: nuclear-directed alteration of a mitochondrial population

Two nuclear genes, Fr and Fr2, have been identified that restore pollen fertility to cytoplasmic male sterile (CMS) common bean (Phaseolus vulgaris L.) by apparently distinct mechanisms. Whereas Fr2 appears to suppress the expression of a male sterility associated mitochondrial sequence (designated pvs), Fr restores pollen fertility by causing the elimination of this unusual mitochondrial DNA-segment. To further investigate the mechanism of Fr action, Fr and Fr2 were cointroduced into the nucleus of a bean line containing the sterility inducing cytoplasm. When the effect of pvs was suppressed by Fr2, the presence of Fr no longer directed the elimination of the mitochondrial pvs sequence. This result suggests that the Fr function is dependent on proper expression of the pvs sequence. To evaluate the temporal and spatial patterns of Fr action, we undertook a polymerase chain reaction-based approach to trace the fate of the pvs sequence in different tissues of F2 and F3 fertile-restored plants derived from a genetic cross between a cytoplasmic male sterile line of common bean, CMS-Sprite (frfr), and fertility restorer line R351 (FrFr). We demonstrate that the Fr-directed disappearance of pvs sequence occurs during flower development. Elimination of the pvs sequence from developing megaspores results in permanent fertility restoration in the following generations. Genetic analysis demonstrated that permanent fertility restoration, that is, the complete elimination of pvs from reproductive tissues requires two doses of the Fr allele or the absence of fr in F2 individuals.(ABSTRACT TRUNCATED AT 250 WORDS)

[A comparison study of various anterior capsulectomies]

The incidences of anterior capsular radial tears occurring in different capsulectomies performed on rabbit eyes under standardized conditions were compared. The eyes were randomly divided into 4 technique groups: (1) can opener, (2) capsulopuncture, (3) linear capsulotomy and (4) continuous circular capsulorhexis (CCC). The results demonstrated that the CCC technique has more advantages in comparison with other three groups. With the nuclear expression technique used in this study, no radial tears occurred with the CCC technique, whereas radial tears occurred in 100% of cases treated with other three techniques.

Increased concentrations of lactate dehydrogenase in pregnancy with preeclampsia: a predictor for the birth of small-for-gestational-age infants

Lactate dehydrogenase (LDH), alanine aminotransferase (ALT) and aspartate aminotransferase (AST) concentrations and platelet counts were measured in 26 normal pregnant women and 51 preeclamptic women. In the normal-pregnancy group, no significant changes were found in the results of these tests. In the preeclampsia group, ALT and AST concentrations were not significantly higher than those in normal pregnancy, but the LDH concentrations increased and the platelet counts decreased significantly through the pregnancy. The increases in LDH did not correlate with changes in ALT or AST. Preeclamptic women with small-for-gestational-age (SGA) infants had significantly higher LDH concentrations than those in the appropriate-for-gestational-age (AGA) group, but ALT and AST concentrations did not increase significantly. As reasons for the LDH increase in our subjects, liver damage was excluded and more active glycolysis in addition to severe cell damage due to chronic anoxemia were inferred. It is suggested that an increase in LDH is predictive of SGA infants in preeclamptic pregnancy, especially in those with normal liver function.

Lovastatin induces growth inhibition and apoptosis in human malignant glioma cells

The competitive HMG-CoA reductase inhibitor lovastatin has been shown to suppress growth and induce morphological changes in a variety of non-glioma tumor cell lines. This study assesses the effects of this agent on the growth and survival of the human malignant glioma cell lines A172 and U87-MG. The response to the drug was investigated using a cell proliferation assay which revealed significant dose-dependent growth inhibition. Treatment with as little as 100 nM lovastatin over a period of 72 hours led to DNA degradation into nucleosome-sized fragments characteristic of apoptosis. Our data suggest that HMG-CoA reductase inhibitors such as lovastatin merit further investigation as potential therapeutic agents for the treatment of malignant gliomas.

Effect of papaya latex against Ascaris suum in naturally infected pigs

An experiment was carried out to investigate the anthelmintic activity of papaya latex (Carica papaya) against natural infection of Ascaris suum in pigs. Sixteen naturally infected pigs were, on the basis of faecal egg counts and body weight, allocated into four groups, each of four pigs. Three groups (groups B, C, and D) were given papaya latex per os at dose levels of 2, 4, and 8 g of papaya latex per kg body weight, respectively. The fourth group (group A) served as a non-treated control. Results of post mortem counts on day 7 post treatment revealed worm count reductions of 39.5, 80.1 and 100% in groups B, C, and D, respectively. Some of the pigs receiving the highest dose of the latex showed mild diarrhoea on the day following treatment. Otherwise, no clinical or pathological changes were observed in the treated animals. The possible future use of this traditional herbal medicine for livestock and humans is discussed.

Rapid culture and quantitation of human immunodeficiency virus type 1 from patient cells without the use of mitogen-stimulated donor cells

We report the development of a rapid, sensitive virus culture method for direct quantitation of human immunodeficiency virus (HIV) in peripheral blood mononuclear cells (PBMCs). This new method involves culturing 10(7) PBMCs from HIV-seropositive persons in 10 ml of medium containing phorbol 12-myristate 13-acetate and interleukin-2. Both agents stimulate cell activation and hence viral replication. Cell-associated virus and free virus are quantitated by a commercially available HIV p24 antigen capture enzyme immunoassay. Detection of cell-associated p24 antigen by flow cytometry was less sensitive than by the enzyme immunoassay. In this preliminary study, HIV was detected in 20 of 23 HIV-seropositive patients and in none of the 11 HIV seronegative low-risk individuals. One HIV-seronegative person with Guillain-Barré syndrome following high-risk activity was found to be rapid-HIV-culture positive. The overall sensitivity and specificity were 87 and 100%, respectively. By comparing the quantity of virus produced in infected cells with the amount of virus produced in chronically infected U1 monocytes and ACH-2 lymphocytes stimulated with phorbol 12-myristate 13-acetate and interleukin-2, the approximate number of infected cells per sample is calculated. In the same patient specimens, quantitation of the number of HIV infected cells by the HIV rapid-culture method correlated with the results of the 21-day cell dilution coculture assay (correlation coefficient r = 0.5; 95% confidence interval, 0.07 to 0.77). Advantages of the rapid HIV culture include no requirement for donor PBMCs or change of media, shortened culture time, and the ability to detect p24 viral antigen from cell-associated virus for quantitation of viral load.

Interleukin 4 receptor signaling in human monocytes and U937 cells involves the activation of a phosphatidylcholine-specific phospholipase C: a comparison with chemotactic peptide, FMLP, phospholipase D, and sphingomyelinase

Interleukin 4 (IL-4) diminishes cytokine activation of human macrophage. IL-4 binding to monocyte IL-4R is associated with protein kinase C (PKC) translocation to a nuclear fraction. The cleavage of diacyglycerol (DAG), an activator of PKC, from membrane phospholipids was investigated to define the proximal events of IL-4R signaling. IL-4 induced a statistically significant time-and dose-dependent generation of DAG. The IL-4-triggered production of DAG was not derived from phosphatidylinositol 4,5-bisphosphate (PIP2) hydrolysis, since neither cytosolic calcium flux nor liberation of inositol phosphates was detected in response to IL-4. Experiments were performed using [14C-methyl]choline-labeled U937 cells and monocytes to determine whether IL-4R activated phospholipase C (PLC), PLD, or PLA2 to use membrane phosphatidylcholine (PC) to form DAG. IL-4 induced a time- and dose-dependent increase of phosphocholine (pchol) with concomitant degradation of membrane PC (p < 0.05 compared with control). The finding that the peak reduction of PC was equivalent to peak production of pchol suggested that IL-4R signaling involved the activation of a PC-specific PLC. Changes in choline (chol) or lyso-PC and glycerolphosphocholine, the respective products of PC cleavage by PLD or PLA2, were not detected in IL-4-treated cells. In contrast, exogenous PLD induced an increase in chol and concomitant loss of membrane PC. Additional investigation suggested that IL-4R signaling does not involve PLD. In cells labeled with L-lyso-3-PC 1-[1-14C]palmitoyl, PLD but not IL-4, increased the production of phosphatidic acid (PA) and phosphatidyl-ethanol when pretreated with ethanol. Propranolol, an inhibitor of phosphatidate phosphohydrolase, and calyculin A, a phosphatase 1 and 2A inhibitor, blocked DAG production in response to FMLP but not to IL-4. In propranolol pretreated cells, PMA but not IL-4 triggered the production of PA and lowered the amount of DAG. Evidence that PLA2 is not coupled to IL-4R is the detection of arachidonate production in response to FMLP but not to IL-4. Furthermore, IL-4R is not coupled to sphingomyelinase (SMase) since IL-4, unlike exogenous SMase, did not generate ceramide but induced the hydrolysis of PC to pchol that was comparable to exogenous PLC. In summary, IL-4R signaling in monocytes and U937 cells involves PLC and not PLD, PLA2, or SMase, and it uses PC and not PIP2 to form DAG.

Hypericin: a potential antiglioma therapy

Hypericin, a polycyclic aromatic dione isolated from plants, is presently being clinically evaluated as an antiviral agent in the treatment of human immunodeficiency virus (HIV) infection. In addition, it is known to be a potent protein kinase C inhibitor. To evaluate its potential as an inhibitor of glioma growth, an established (U87) and low-passage glioma line (93-492) were treated with hypericin in tissue culture for a period of 48 hours after passage. Hypericin inhibited the glioma growth in a dose-related manner, with a marked inhibition of growth in the low-micromolar concentration range (e.g., in line U87 and low-passage line 93-492, a concentration of hypericin of 10 mumol/L produced 62 and 76% decreases in [3H]thymidine uptake, respectively). Because the reported inhibitory effects of protein kinase C are enhanced by visible light, [3H]thymidine uptake was measured in both the presence and the absence of visible light. In glioma line A172, the presence of light slightly increased the inhibitory effect of hypericin. Moreover, an apoptosis (i.e., programmed cell death) assay was performed to determine whether the treatment of glioma cells with hypericin was cytostatic or cytocidal. Cells were harvested, and purified deoxyribonucleic acid (DNA) was analyzed by agarose gel electrophoresis. DNA from cells treated with hypericin for 48 hours exhibited a classical "ladder" pattern of oligonucleosome-sized fragments characteristic of apoptosis. These data suggest that the proven safe drug hypericin may have potential as an antiglioma agent; we suggest clinical trials.

[Biodistribution and metabolism of 3H-gastrodigenin and 3H-gastrodin in mice]

The biodistribution and metabolism of 3H-gastrodigenin and 3H-gastrodin after intravenous injection were studied by the detection of their radioactivity in mice tissue; the radioactive elements of mice tissue extracts after intravenous injection of 3H-gastrodin were analyzed with thin-layer chromatography (TLC). The results demonstrated that gastrodin could penetrate through the blood-brain barrier into the brain, and it was rapidly decomposed into the gastrodigenin in brain, liver and blood. Then gastrodigenin preserved in brain and mediated its pharmacological inhibitive effects on the central nervous system. Most of the gastrodigenin and gastrodin were excreted by the kidney. The findings also suggested that gastrodin might exist in the enterohepatic circulation.

[Resection of the caudate lobe of the liver]

It is difficult and dangerous to remove the caudate lobe of the liver because it not only is deeply embedded between the hilar structures of the liver and inferior vena cava but has its own independent vascular and biliary systems also. Two successful cases of caudate lobe resection are reported with review of literature and discussions on its applied anatomy, image-diagnosis, indications on surgery, technique and method of caudate lobe resection.

Protein kinase C inhibitors induce apoptosis in human malignant glioma cell lines

Previous work has demonstrated the importance of the protein kinase C (PKC) system in regulating glioma growth, and has led to clinical trials utilizing PKC inhibitors as adjuncts in the therapy of patients harboring malignant gliomas. This study was performed to explore the possibility that inhibition of PKC in gliomas was triggering an apoptosis signal. Glioma cell lines were treated with PKC inhibitors staurosporine (10 nM), and tamoxifen (10 microM). DNA from cells treated with each of these drugs exhibited a 'ladder' pattern of oligonucleosome-sized fragments characteristic of apoptosis, thus suggesting that in glioma cells, these drugs may be cytocidal in action.

Dexamethasone induced proliferation of cultured retinal pigment epithelial cells

Dexamethasone (DEX) is a glucocorticoid that is widely used after vitreoretinal surgery and may have mitogenic properties. This study was initiated to determine if human cultured retinal pigment epithelium (RPE) cells express glucocorticoid receptor and proliferate in response to DEX stimulation. Glucocorticoid receptor mRNA was detected in RPE cells by means of reverse transcriptase polymerase chain reaction. To determine the effect of DEX on RPE cell proliferation in vitro, we cultured human RPE cells with various concentrations for DEX for 5 days and determined the effects on cell number and incorporation of tritiated thymidine. DEX treatment with a DEX dose of 1 microgram/ml in the presence or absence of serum resulted in a maximal 2-3 times increase in cell number. Autoradiography after thymidine incorporation revealed a greater than 2-fold increase in incorporating cells at this same dose. These results indicate that DEX causes cultured human RPE cells to proliferate and suggest that it may have a growth factor-like action.

Transplantation of cultured human retinal pigment epithelium into rabbit subretina

Transplantation of normal retinal pigment epithelium (RPE) into a diseased eye holds promise for treatment of several blinding disorders. Previous studies have involved immunosuppression and implantation of freshly isolated cells. We report here the successful transplantation of cultured human RPE cells into rabbits that were not immunosuppressed. A modified pars plana transvitreal technique was used for RPE transplantation. The cultured RPE cells, loaded with carbon as a marker, were transplanted into the denuded Bruch's membrane of albino rabbits. The animals were followed for from 1 week to 3 months. On histologic examination at 2 months, no infiltrating lymphocytes were found in the vitreous cavity or choroid, even though Bruch's membrane was damaged. At about 3 months there were some macrophages in the subretina of transplanted eyes, indicating that an immunoreaction does occur eventually. Electron microscopy of the transplanted RPE showed apical-basal polarity and gap junctions. Restored function was attested to by the presence of phagosomes and phagocytosed outer segments in the transplanted cells. Our findings suggest that there is a weak, delayed immunoreaction to human RPE cells transplanted beneath the retina of the rabbit; however, functional recovery of the transplanted cells occurs before this immune response develops.

IL-6 down-modulates the cytokine-enhanced antileishmanial activity in human macrophages

IL-6 is a cytokine synthesized by T cells and macrophages (M phi). It has pleiotropic effects on diverse cell types and is recognized for its "pro-inflammatory" properties. In mice, IL-4, IL-5, IL-6, and IL-10 are produced by Th-2 cells. Because IL-10 suppresses Th-1 clones, and IL-4 broadly deactivates M phi, experiments were carried out to investigate the in vitro effects of recombinant human IL-6 on cytokine activation of human M phi. Pretreatment with IL-6 induced a dose- and time-dependent suppression of IFN-gamma (1000 U/mL) and TNF-alpha (25 ng/mL) activation of M phi for the killing of L. amazonensis. At doses greater than 0.1 to 100 ng/mL, IL-6 inhibited IFN-gamma and TNF-alpha activation by 21 to 93% and 36 to 82%, respectively. IL-6 alone had no effect on M phi viability and intracellular L. amazonensis growth. Blockade of M phi activation was greatest when IL-6 was added 24 or 48 h before infection and treatment with IFN-gamma or TNF-alpha. Furthermore, mAb against IL-6 abrogated the inhibitory activity of IL-6. Similarly IL-6 pretreatment suppressed M phi activation for antileishmanial capacity by IL-3, granulocyte-monocyte-CSF (GM-CSF) and IL-1 beta. Because cytokine induction of antileishmanial activity is associated with enhancement of oxidative capacity, the effect of IL-6 on this mechanism was evaluated. Pretreatment with IL-6 down-modulated TNF-alpha (25 ng/mL) enhancement of M phi oxidative capacity in a dose- and time-dependent manner. A similar depression of oxidative capacity was observed for GM-CSF and IL-3 but not for IFN-gamma. Furthermore, NG-monomethyl-L-arginine (a nitric oxide synthase inhibitor) had no effect on IFN-gamma and TNF-alpha activation of antileishmanial activity and nitrites/nitrates were not reliably assayed from M phi culture supernatants. These findings suggest that IL-6 down-modulates cytokine activation of M phi antileishmanial capacity by inhibiting oxygen-dependent and undefined oxygen-independent mechanisms.

Retrospective study comparing the pathophysiology of antibiotic-treated and untreated Escherichia coli- and Staphylococcus aureus-infused baboons

Escherichia coli and Staphylococcus aureus are the most common pathogens encountered in septic shock. This is a descriptive study in which the pathophysiologic response to infusions of LD100 concentrations of E. coli and S. aureus are staged and compared. Equivalent concentrations of both organisms were infused over a 2 hr period into antibiotic-treated and untreated animals with the following results: 1) The apparent clearance of E. coli was less than that of S. aureus over the 2-hr infusion period, but far greater during the next 8 hr in both antibiotic-treated and untreated animals. Thus the clearance of E. coli fits a one-compartment (intravascular), and that of S. aureus fits a two-compartment (intra- and extravascular) model. 2) The intensity of the cardiovascular, temperature, and metabolic response to E. coli was greater, whereas that of the disseminated intravascular coagulant (DIC) response to S. aureus was greater. We conclude, therefore, that the response to E. coli consists of four stages with no invasion and colonization of tissues, whereas the response to S. aureus consists of two stages with invasion and colonization of tissues.

IL-6 down-modulates the cytokine-enhanced antileishmanial activity in human macrophages

IL-6 is a cytokine synthesized by T cells and macrophages (M phi). It has pleiotropic effects on diverse cell types and is recognized for its "pro-inflammatory" properties. In mice, IL-4, IL-5, IL-6, and IL-10 are produced by Th-2 cells. Because IL-10 suppresses Th-1 clones, and IL-4 broadly deactivates M phi, experiments were carried out to investigate the in vitro effects of recombinant human IL-6 on cytokine activation of human M phi. Pretreatment with IL-6 induced a dose- and time-dependent suppression of IFN-gamma (1000 U/mL) and TNF-alpha (25 ng/mL) activation of M phi for the killing of L. amazonensis. At doses greater than 0.1 to 100 ng/mL, IL-6 inhibited IFN-gamma and TNF-alpha activation by 21 to 93% and 36 to 82%, respectively. IL-6 alone had no effect on M phi viability and intracellular L. amazonensis growth. Blockade of M phi activation was greatest when IL-6 was added 24 or 48 h before infection and treatment with IFN-gamma or TNF-alpha. Furthermore, mAb against IL-6 abrogated the inhibitory activity of IL-6. Similarly IL-6 pretreatment suppressed M phi activation for antileishmanial capacity by IL-3, granulocyte-monocyte-CSF (GM-CSF) and IL-1 beta. Because cytokine induction of antileishmanial activity is associated with enhancement of oxidative capacity, the effect of IL-6 on this mechanism was evaluated. Pretreatment with IL-6 down-modulated TNF-alpha (25 ng/mL) enhancement of M phi oxidative capacity in a dose- and time-dependent manner. A similar depression of oxidative capacity was observed for GM-CSF and IL-3 but not for IFN-gamma. Furthermore, NG-monomethyl-L-arginine (a nitric oxide synthase inhibitor) had no effect on IFN-gamma and TNF-alpha activation of antileishmanial activity and nitrites/nitrates were not reliably assayed from M phi culture supernatants. These findings suggest that IL-6 down-modulates cytokine activation of M phi antileishmanial capacity by inhibiting oxygen-dependent and undefined oxygen-independent mechanisms.

Visible flicker from invisible patterns

Using a laser interferometer we can create grating patterns of high optical contrast (interference fringes) directly on the retina. With coarse fringe patterns, the alternating light and dark bars of the pattern can be seen, but the bars of the finest fringes are not subjectively resolved. We report here that when we rapidly modulate the contrast of a fine fringe pattern (keeping overall luminance constant), observers experience flicker, even if the fringes are too finely spaced to be perceived as a grating. For this flicker to be seen, the pattern needs to be resolvable by the photoreceptors themselves, but not necessarily by later stages of visual processing. It can be explained if, in man, signals associated with individual cone receptors do not depend linearly on light intensity, but instead are scaled by a fast sensitivity-regulating or light-adaptation mechanism. Contrast-modulation flicker is not demonstrable in rod vision; rod vision therefore lacks such a local adaptation process.

Cytogenetic damage and tumor incidence in mouse skin after single, topical applications of 7,12-dimethylbenz[a]anthracene

Micronucleus induction, chromosomal damage and aneuploidy were evaluated in whole skin keratinocyte cultures derived from HRA/Skh mice after single in vivo applications of 0.256, 2.56 and 25.6 micrograms (1, 10 and 100 nmoles) of the carcinogen, 7,12-dimethylbenz[a]anthracene (DMBA). These genotoxicity end-points were compared with papilloma and carcinoma occurrence at the same dose levels of carcinogen. While the lower 2 doses of DMBA significantly increased the incidence of micronuclei and other chromosomal anomalies in keratinocytes, the two highest doses resulted in a significantly increased papilloma yield (0.297 and 3.895 papillomas/mouse) and incidence (24.3 and 100%). Carcinomas appeared only at the highest dose (0.125 carcinomas/mouse; 5% incidence). Neither papillomas nor carcinomas occurred in solvent-treated control mice. None of the three applied doses induced aneuploidy under conditions leading to an increase in tumors and/or chromosomal damage.

Detection of DNA sequence polymorphisms among wheat varieties

A DNA marker detection strategy that allows the rapid, efficient resolution of high levels of polymorphism among closely related lines of common wheat (Triticum aestivum) has been developed to circumvent the apparent lack of restriction fragment length polymorphism in many important self-pollinated crop species. The technique of randomly amplified polymorphic DNA (RAPD) was combined with a denaturing gradient gel electrophoresis system (DGGE) to explore DNA sequence polymorphisms among different genotypes of wheat. Of the 65 primer combinations used for the polymerase chain reaction (PCR) amplifications, over 38% of them produced readily detectable and reproducible DNA polymorphisms between a spring wheat line, SO852, and a winter wheat variety, 'Clark'. A high level of polymorphism was observed among a number of commercial varieties and breeding lines of wheat. This procedure was also used to detect polymorphisms in a recombinant inbred population to test the feasibility of its application in genome mapping. This DNA polymorphism detection system provides an opportunity for pedigree analysis and fingerprinting of developed wheat lines as well as construction of a high density genetic map of wheat. Without the need for (32)P and sophisticated DNA extraction procedures, this approach should make it feasible to utilize marker-based selection in a plant breeding program.