Decreased chaperone activity of alpha-crystallins in naphthalene-induced cataract possibly results from C-terminal truncation

Naphthalene-induced cataract has been extensively used to test potential anticataract drugs. Because the morphology as well as the toxic manifestations of naphthalene-induced cataract are reported to be similar to that of age-related cataract, naphthalene cataractogenesis in rats has been used as a valuable animal model to study the aetiology of age-related cataract in humans. This study aimed to determine whether the molecular chaperone activity of the alpha-crystallins was altered in naphthalene-induced cataract, and to clarify the possible mechanism for these changes. The data showed that the chaperone activity of the alpha-crystallins decreased in naphthalene-induced cataract. By mass spectrometry, C-terminal truncation of 16 amino acids and other post-translational modifications such as acetylation, phosphorylation, oxidation and carbamylation of the alpha-crystallins were detected. Furthermore, the results suggested that, at the proteomics level, naphthalene-induced cataract is a valuable animal model for the study of age-related cataract in humans.

Sub-Doppler cooling of fermionic Hg isotopes in a magneto-optical trap

Laser cooling and trapping of neutral mercury is performed in a single-stage (1)S(0)↔(3)P(1) 3D magneto-optical trap. We give a detailed account of the atom cloud size and temperature for both bosonic ((200)Hg and (202)Hg) and fermionic ((199)Hg and (201)Hg) isotopes. The bosonic isotope temperatures are in close agreement with Doppler cooling theory, while temperatures obtained for the fermionic isotopes are lower, suggesting the presence of sub-Doppler cooling. A minimum temperature of 29±4 μK is achieved for (201)Hg.

First Report of Alternaria Brown Spot of Citrus Caused by Alternaria alternata in Yunnan Province, China

Brown spot of citrus is considered a major problem on the fruit of many citrus cultivars grown for fresh markets including tangerines (Citrus reticulata) and their hybrids. It causes lesions on leaves, stems, and fruit and reduces yield and fruit quality (2). In 2003 in southern Wenshan Municipality, Yunnan Province in China, sporadic occurrence of Alternaria brown spot was observed on Tangfang mandarin, a local citrus cultivar identified preliminarily as a kind of mandarin hybrid. From 2006 to 2008, nearly 80% of local orchards were infected with the disease. Fruit symptoms typical of Alternaria brown spot ranging from light brown, slightly depressed spots to circular and dark brown areas were observed. Leaves showed small, brown, circular spots and irregular blighted areas with characteristic yellow halos. Tissues from the margin of fruit spots or infected leaf parts of eight different trees were surface sterilized in 1.5% sodium hypochlorite for 1 min, plated on potato dextrose agar (PDA), and then incubated at 27°C in the dark for 1 week. Dark brown mycelia and pigmented septate conidia with lengths of 10 to 35 μm and widths of 5 to 13 μm were produced. On the basis of conidial morphological characteristics, the pathogen was identified as Alternaria alternata (Fr.:Fr.) Keissl (1). Detached young healthy leaves of 'Minneola' tangelo (C. reticulata × C. paradisi) were sprayed with a conidial suspension of 10⁵ conidia per ml and incubated in a moist chamber at 27°C. A control treatment with an equal number of leaves was sprayed with distilled water only. After 48 h, seven of these isolates caused necrotic lesions on detached leaves, characteristic of the disease, whereas there were no symptoms on leaves of the water control. Pure cultures were recovered on PDA from symptomatic tissues and the morphological characteristics of the conidia closely fit the description of A. alternata, confirming Koch's postulates. Currently, the distribution of Alternaria brown spot of citrus is confined to southern Wenshan Municipality in Yunnan Province where it is a serious disease problem on the most important commercial cultivar in this region. The identification of the pathogen now allows for appropriate field management and control measures. To our knowledge, this is the first report of Alternaria brown spot of citrus in China. References: (1) Z. Solel. Plant Pathol. 40:145, 1991. (2) J. O. Whiteside. Plant Dis. Rep. 60:326, 1976.

Expression of Frizzled 2 in the mouse ovary during oestrous cycle

The Wnt/beta-catenin pathway is a conserved signalling pathway that regulates gene expression and controls diverse developmental processes such as cell fate specification, cell proliferation and cell differentiation. To our knowledge, the potential role of this pathway in the adult ovary has been poorly addressed. To this end, we investigated the expression pattern of Frizzled 2 in the mouse ovary during oestrous cycle by real-time Q-PCR, in situ hybridization, Western blotting and immunohistochemistry. In this study, we used uterine wet weight and H3.2 mRNA level as two markers for classification of mouse oestrous cycle. We found that both uterine wet weight and H3.2 mRNA are the highest in the proestrus and decrease from oestrus to diestrus. During oestrous cycle, Frizzled 2 mRNA and protein exhibited the highest level in the proestrus stage and rapidly reduced from oestrus to diestrus. In situ hybridization results showed that the positive signals for Frizzled 2 are highly detected in the oocyte and stroma in proestrus stage, while moderate or weak Frizzled 2 mRNAs are localized in the oocyte, granulosa cells, stroma and corpus luteum from oestrus to diestrus. The localization pattern of Frizzled 2 protein is mostly consistent with its mRNA, but stronger Frizzled 2 proteins are present in the granulosa cells and membrane of oocyte in oestrous cycle. Our data suggest that Frizzled 2 may be involved in regulating follicle growth, oocyte maturation and luteinization during oestrous cycle.

Reg IV enhances peritoneal metastasis in gastric carcinomas

OBJECTIVES

The role of Regenerating (Reg) IV on peritoneal metastasis was examined in gastric cancer using.

MATERIAL AND METHODS

Reg IV-transfected human gastric cancer cells (MKN28-R1, MKN28-R2, TMK1-R1), control transfectants (MKN28-R0, TMK1-R0), and REG4-knocked down MKN45 cells were examined in in vitro and in nude mice peritoneal metastasis models.

RESULTS AND DISCUSSION

Increase of expression and secretion of Reg IV, and levels of BCL-2, BCL-XL,survivin, phosphorylated AKT, and phosphorylated EGFR, and decrease of nitric oxide-induced apoptosis were found in Reg IV-transfectants, whereas those were abrogated in the knockdown cells. In mice models, increased number and size of peritoneal tumors and decreased apoptosis were found in Reg IV-transfectants, whereas those were abrogated by the knockdown cells. Mice survivals were worsened in Reg IV-transfectants-inoculated mice, but were improved in Reg IV-knockdown cell-inoculated mice. Levels of Reg IV protein in peritoneal lavage fluids increased in Reg IV-transfectants inoculated mice, but decreased in Reg IV-knockdown cell inoculated mice. In metastasized human gastric cancers, Reg IV positivity in peritoneum-metastasis cases was higher than those in negative cases. Reg IV was detected in peritoneal lavage fluids from human gastric cancer patients, in whose lavages keratin mRNA was detected by reverse transcriptase-polymerase chain reaction. Collectively, Reg IV might accelerate peritoneal metastasis in gastric cancer. Reg IV in lavage fluids might be a good marker for peritoneal metastasis.

Mesenchymal Stem Cells Genetically Modified with the Angiopoietin-1 Gene Enhanced Arteriogenesis in a Porcine Model of Chronic Myocardial Ischaemia

The direct injection by thoracoscope of mesenchymal stem cells (MSCs) that had been genetically modified to express angiopoietin-1 was investigated in a porcine model to determine their effect on arteriogenesis and the effectiveness of this technique. Chronic myocardial ischaemia was established using a thoracoscope to insert an ameroid constrictor around the left circumflex coronary artery. Six weeks after establishing the ischaemia, 20 pigs were randomly divided into three groups to receive injections by thoracoscope of either genetically-modified MSCs, unmodified MSCs or phosphate-buffered saline into the ischaemic border area. The injections were repeated 1 month later. The genetically modified MSCs were found to restore blood flow significantly more than the other observed treatments and immunohistochemical evaluation of arteriogenesis supported this finding. In conclusion, the injection of MSCs that had been genetically modified to express angiopoietin-1 improved arteriogenesis and increased collateral blood flow in the myocardial ischaemic area. Thoracoscope delivery of the injection was safe and minimally invasive.

Detection of human cytomegalovirus in the atherosclerotic cerebral arteries in Han population in China

The association of atherosclerosis (AS) and Human cytomegalovirus (HCMV) infection was studied. AS plays an important role in the brain stroke and HCMV infection is supposed to be involved in the process of atherosclerotic formation. The presence of HCMV DNA and antigens was examined in the internal carotid arteries collected from 35 patients with ischemic stroke and from 20 patients from the control population. All patients belonged to the ethnic Han population in China. Three methods, immunohistochemistry (IHC), hybridization in situ (HIS), and PCR were used to detect the HCMV immediate early (IE) and late (L) antigens as well as viral DNA in vessel walls. Levels of HCMV IE gene/protein were significantly higher in the stroke group than in control group detected by the three methods (IHC 34.3% vs. 10.0%; HIS 40.0% vs. 10.0; PCR 60.0% vs. 30.0%). However, there was no significant difference in the levels of HCMV L gene/protein between these two groups of patients (IHC 11.4% vs. 5.0%; HIS 11.4% vs. 10.0%; PCR 20.0% vs. 20.0%). We concluded that the presence of HCMV IE antigen and HCMV DNA in the vessel wall was associated with the pathological process of AS formation.

Baicalin reduces the severity of experimental autoimmune encephalomyelitis

Scutellaria baicalensis Georgi is one of the important medicinal herbs widely used for the treatment of various inflammatory diseases in Asia. Baicalin (BA) is a bioactive anti-inflammatory flavone found abundantly in Scutellaria baicalensis Georgi. To explore the therapeutic potential of BA, we examined the effects of systemic administration of the flavone (5 and 10 mg/kg, ip) on relapsing/remitting experimental autoimmune encephalomyelitis (EAE) induced by proteolipid protein 139-151 in SJL/J mice, an experimental model of multiple sclerosis. The mice treated with PBS or BA at day -1 and for 3 consecutive days were observed daily for clinical signs of disease up to 60 days after immunization. In the PBS-EAE group, neurological scores were: incidence (100%), mean day of onset (8.0 +/- 0.73), peak clinical score (3.0 +/- 0.4), and cumulative disease index (141.8 +/- 19.4). In the BA-EAE group (5 or 10 mg kg(-1) day(-1), respectively), incidence (95 or 90%), mean day of onset (9.0 +/- 0.80 or 9.2 +/- 0.75; P = 0.000), peak clinical score (2.2 +/- 0.3 or 2.0 +/- 0.3; P = 0.000), and cumulative disease index (75.9 +/- 10.1 or 62.9 +/- 8.4; P = 0.000) decreased, accompanied by the histopathological findings (decrease of dense mononuclear infiltration surrounding vascellum) for the spinal cord. Additionally, the in vitro effects of BA (5, 10, and 25 microM) on mononuclear cells collected from popliteal and inguinal lymph nodes of day-10 EAE mice were evaluated using an MTT reduction assay for cell proliferation, and ELISA to measure IFN-gamma and IL-4 cytokines. Compared with the control group, BA caused an increase in IL-4 (EAE-DMSO: 3.56 +/- 0.42 pg/mL vs EAE-BA (5, 10, and 25 microM): 6.03 +/- 1.1, 7.83 +/- 0.65, 10.54 +/- 1.13 pg/mL, respectively; P < 0.001); but inhibited IFN-gamma (EAE-DMSO: 485.76 +/- 25.13 pg/mL vs EAE-BA (5, 10, and 25 microM): 87.08 +/- 9.24, 36.27 +/- 5.44, 19.18 +/- 2.93 pg/mL, respectively; P < 0.001) and the proliferation of mononuclear cells (EAE-DMSO: 0.73 +/- 0.021 vs EAE-BA (5, 10, and 25 microM): 0.41 +/- 0.015, 0.31 +/- 0.018, 0.21 +/- 0.11, respectively; P < 0.001) in a concentration-dependent manner. The results suggest that BA might be effective in the treatment of multiple sclerosis.

Association of ACE, ACE2 and UTS2 polymorphisms with essential hypertension in Han and Dongxiang populations from north-western China

To assess the significance of polymorphisms of the genes for angiotensin-converting enzyme (ACE), angiotensin-converting enzyme 2 (ACE2) and urotensin II (UTS2) as risk factors for essential hypertension in two populations from north-western China, we enrolled 198 patients with essential hypertension and 131 healthy controls from the Han population and 120 patients with essential hypertension and 102 healthy controls from the Dongxiang population. Polymerase chain reaction (PCR) and PCR-restriction fragment length polymorphism were used to analyse gene polymorphisms. The results provided evidence that genetic variants of UTS2 and ACE2 may play a role in the development of essential hypertension in these populations. Polymorphisms of ACE were not associated with essential hypertension in either population. This is the first report showing that the S89N single-nucleotide polymorphism of the UTS2 gene is associated with essential hypertension.

Operative versus non-operative treatment for thoracolumbar burst fractures without neurological deficit

BACKGROUND

Spinal burst fractures result from the failure of both the anterior and the middle columns of the spine under axial compression loads. Conservative management is through bed rest, and immobilization with a brace once the acute symptoms have settled. Surgical treatment involves either anterior or posterior stabilization of the fracture with screws, often with decompression, an operation to remove bone fragments which have intruded into the vertebral canal.

OBJECTIVES

To compare operative with non-operative treatment for thoracolumbar burst fractures without neurological deficit.

SEARCH STRATEGY

We searched the Cochrane Bone, Joint and Muscle Trauma Group Specialized Register (May 2005), the Cochrane Central Register of Controlled Trials (The Cochrane Library Issue 2, 2005), MEDLINE (January 1966 to April 2005), EMBASE (January 1988 to April 2005), and the Chinese Biomedical Literature Database (CBM) available at http://cbm.imicams.ac.cn (January 1978 to April 2005). We also searched reference lists of articles, handsearched journals and conference proceedings, and contacted authors where necessary.

SELECTION CRITERIA

Randomized controlled trials (RCTs) comparing operative with non-operative treatment of thoracolumbar burst fractures without neurological deficit.

DATA COLLECTION AND ANALYSIS

Two review authors assessed trial quality and extracted data independently. Pooling of data was not carried out as only one small, poor quality trial was included.

MAIN RESULTS

We included one trial comparing operative with non-operative treatment (53 participants). There was no statistically significant difference in pain and function-related outcomes, rates of return to work, radiographic findings or average length of hospitalization at final follow up. The rate of complications was higher for the patients treated operatively. The degree of kyphosis or the percentage of correction lost did not correlate with any clinical symptoms at the time of the final follow up. Average costs related to hospitalization and treatment in the operative group appeared to be more than in the non-operative group.

AUTHORS' CONCLUSIONS

There was no statistically significant difference on the functional outcome two years or more after therapy between operative and non-operative treatment for thoracolumbar burst fractures without neurological deficit. However, this review was able to include only one randomized controlled trial with a small sample size and poor quality, which precluded firm conclusions. More research with high quality trials is needed.

A New Cardiac Concordant Xenotransplantation Model

OBJECTIVE

A simplified method of heterotopic abdominal cardiac xenotransplantation and its technique problems are described.

METHODS

Hamster-to-rat cardiac xenotransplantation was performed by means of "sleeve and cuff" method. The left common carotid artery of the donor heart was anastomosed to the left renal artery of the recipient with a "sleeve" anastomosis, and the "cuffed" right pulmonary artery was anastamosed to the left renal vein of the rat. The viability of the donor heart was examined daily by palpating the left abdominal wall of the rat.

RESULTS

Among 105 rats that underwent heterotopic cardiac xenotransplantation, 95 were completed successfully. The xenograft survived for 3 to 4 days after the procedure suffering typical acute vascular rejection.

CONCLUSIONS

A useful, easy model to investigate the mechanisms of concordant xenotransplantation was established.

Low noise figure all-optical gain-clamped parallel C+L band Erbium-doped fiber amplifier using an interleaver

A low noise figure (NF), all-optical gain-clamped C+L band erbium-doped fiber amplifier (EDFA) has been demonstrated. A parallel configuration is employed to avoid the crosstalk between the C- and L-band signals. Half of the amplified spontaneous emission from the output signal is filtered by an interleaver and fed back to the parallel EDFA to form lasing cavity. Two lasers in the C- and L-band, respectively, formed in the cavity clamp the C- and L-band signals simultaneously. In the L-band, the double-pass configuration with a fiber Bragg grating is used to improve the gain and NF. Furthermore, co-propagation of the signal and the lasing power leads to a low NF, while the amplified signals are exported separately from the lasing power. Finally, a wide gain-clamping range up to -10dBm and ~5.5dB NF are obtained.

Treatment of murine breast cancer cells with antisense RNA to the type I insulin-like growth factor receptor decreases the level of plasminogen activator transcripts, inhibits cell growth in vitro, and reduces tumorigenesis in vivo

AIMS

To establish that cells from the murine mammary carcinoma cell line, EMT6, express type I insulin-like growth factor receptor (IGF-IR), tissue-type plasminogen activator (tPA), and urokinase-type plasminogen activator (uPA). To investigate the role of IGF-IR in growth, transformation, and tumorigenesis in addition to its relation to tPA and uPA in EMT6 cells. To assess the suitability of the EMT6/syngeneic mouse model for studying the role of IGF-IR in tumorigenesis.

METHODS

The presence of transcripts for IGF-IR, tPA, and uPA was determined by northern blot analysis using poly (A(+)) RNA derived from EMT6 cells transfected with an antisense IGF-IR construct or a construct lacking the antisense IGF-IR insert. Flow cytometry was used to measure IGF-IR protein. Assays were performed to determine cell proliferation, transformation, and the tumorigenicity of antisense IGF-IR transfected EMT6 cells and control transfected EMT6 cells.

RESULTS

There was strong expression of IGF-IR, tPA, and uPA in EMT6 cells. EMT6 cells from clones carrying antisense IGF-IR displayed a significant decrease in cell proliferation and lost the ability to form colonies in soft agar. A decrease in tumour size occurred when cells carrying the antisense IGF-IR were injected into syngeneic mice. Reduced expression of tPA and uPA was seen in EMT6 cells carrying the antisense IGF-IR construct.

CONCLUSIONS

The IGF-IR plays a role in the progression, transformation, and tumorigenesis of EMT6 murine mammary carcinoma cells. The suppression of IGF-IR mRNA in EMT6 cells decreases tPA and uPA expression. EMT6 cells and the syngeneic mouse provide a suitable model for studying the role of IGF-IR in breast tumour progression.

Function of YidC for the insertion of M13 procoat protein in Escherichia coli: translocation of mutants that show differences in their membrane potential dependence and Sec requirement

The membrane insertion of the Sec-independent M13 Procoat protein in bacteria requires the membrane electrochemical potential and the integral membrane protein YidC. We show here that YidC is involved in the translocation but not in the targeting of the Procoat protein, because we found the protein was partitioned into the membrane in the absence of YidC. YidC can function also to promote membrane insertion of Procoat mutants that insert independently of the membrane potential, proving that the effect of YidC depletion is not due to a dissipation of the membrane potential. We also found that YidC is absolutely required for Sec-dependent translocation of a long periplasmic loop of a mutant Procoat in which the periplasmic region has been extended from 20 to 194 residues. Furthermore, when Sec-dependent membrane proteins with large periplasmic domains were overproduced under YidC-limited conditions, we found that the exported proteins pro-OmpA and pre-peptidoglycan-associated lipoprotein accumulated in the cytoplasm. This suggests for Sec-dependent proteins that YidC functions at a late stage in membrane insertion, after the Sec translocase interacts with the translocating membrane protein. These studies are consistent with the understanding that YidC cooperates with the Sec translocase for membrane translocation and that YidC is required for clearing the protein-conducting channel.

HIV envelope gp120 activates human arterial smooth muscle cells

There have been increasing reports of acute coronary thrombotic events in patients with HIV. Although these clinical events have been attributed primarily to dyslipidemia associated with protease inhibitor therapy, autopsy studies in children with HIV suggest the presence of an underlying arteriopathy. This study demonstrates that the HIV envelope protein, gp120, activates human arterial smooth muscle cells to express tissue factor, the initiator of the coagulation cascade. The induction of tissue factor by gp120 is mediated by two biologically relevant coreceptors for HIV infection, CXCR4 and CCR5, and is also dependent on the presence of functional CD4. Induction of tissue factor by gp120 requires activation of mitogen-activating protein kinases, activation of protein kinase C, and generation of reactive oxygen species, signaling pathways that have protean effects on smooth muscle cell physiology. The activation of smooth muscle cells by gp120 may play an important role in the vascular, thrombotic, and inflammatory responses to HIV infection.

Dipsticks for rapid detection of plasmodium in vectoring anopheles mosquitoes

Malaria remains the most serious vector-borne disease, affecting some 300-500 million people annually, transmitted by many species of Anopheles mosquitoes (Diptera: Culicidae). Monoclonal antibodies developed against specific circumsporozoite (CS) proteins of the main malaria parasites Plasmodium falciparum and P. vivax have been used previously for enzyme-linked immunosorbent assays (ELISA), widely employed for detection of malaria sporozoites in vector Anopheles for local risk assessment, epidemiological studies and targeting vector control. However, ELISA procedures are relatively slow and impractical for field use. To circumvent this, we developed rapid wicking assays that identify the presence or absence of specific peptide epitopes of CS protein of the most important P. falciparum and two strains (variants 210 and 247) of the more widespread P. vivax. The resulting assay is a rapid, one-step procedure using a 'dipstick' wicking test strip. In laboratory assessment, dipsticks identified 1 ng/ mL of any of these three CS protein antigens, with sensitivity nearly equal to the CS standard ELISA. We have developed and are evaluating a combined panel assay that will be both qualitative and quantitative. This quick and easy dipstick test (VecTest Malaria) offers practical advantages for field workers needing to make rapid surveys of malaria vectors.

Intracranial bone marrow transplantation after traumatic brain injury improving functional outcome in adult rats

OBJECT

The authors tested the hypothesis that intracranial bone marrow (BM) transplantation after traumatic brain injury (TBI) in rats provides therapeutic benefit.

METHODS

Sixty-six adult Wistar rats, weighing 275 to 350 g each, were used for the experiment. Bone marrow prelabeled with bromodeoxyuridine (BrdU) was harvested from tibias and femurs of healthy adult rats. Other animals were subjected to controlled cortical impact, and BM was injected adjacent to the contusion 24 hours after the impact. The animals were killed at 4, 7, 14, or 28 days after transplantation. Motor function was evaluated both before and after the injury by using the rotarod test. After the animals had been killed, brain sections were examined using hemotoxylin and eosin and immunohistochemical staining methods. Histological examination revealed that, after transplantation, BM cells survived, proliferated, and migrated toward the injury site. Some of the BrdU-labeled BM cells were reactive, with astrocytic (glial fibrillary acid protein) and neuronal (NeuN and microtubule-associated protein) markers. Transplanted BM expressed proteins phenotypical of intrinsic brain cells, that is, neurons and astrocytes. A statistically significant improvement in motor function in rats that underwent BM transplantation, compared with control rats, was detected at 14 and 28 days posttransplantation.

CONCLUSIONS

On the basis of their findings, the authors assert that BM transplantation improves neurological outcome and that BM cells survive and express nerve cell proteins after TBI.

Detection and nucleotide analysis of RNA5 of beet necrotic yellow vein virus isolated in China

Using the RT-PCR method, five isolates of beet necrotic yellow vein virus from China were used for the RNA5 genomic component detection and sequence analysis. The result showed that RNA5 was only found in the isolates from Baotou and Hohhot, but not in those of Xingjiang, Helongjiang, and Wulate of Inner Mongolia. The RNA5 components had 1338 nucleotides and 1358 nucleotides in the length of Baotou and Hohhot isolates, respectively, in which the single open reading frame (ORF) encoding for a proteins of 26kD were contained. Compared with the published sequences of F72 and D5 isolates, these RNA5 components shared the identity of 93.7% approximately 98.5% in nucleotide acids and 91.8%-98.2% in deduced amino acids.

A microcalorimetric study of the effect of La3+ on mitochondria isolated from Star-Cross 288 chicken liver tissue cells

The thermogenic curves of the metabolism of mitochondria isolated from the liver of chicken Star-Cross 288 and the effect of La3+ on it were studied by using an LKB-2277 BioActivity Monitor, ampoule method, at 37 degrees C. After isolation from the chicken liver tissue, mitochondria still have metabolic activity and can live for a long time by using the stored nutrients. From the thermogenic curves, we obtained the thermokinetic equations under different condition. The kinetic study shows that La3+ has changed the metabolism completely.

Functional characterization of the EMCV IRES in plants

The translation of eukaryotic messenger RNA is typically dependent upon the presence of an m7GpppN cap structure at the 5' end of the transcript. However, several animal viruses, including the Picorna viruses, have been shown to exhibit cap-independent translation through the presence of an internal ribosome entry site or IRES. This IRES-mediated cap-independent internal translation initiation has been exploited to generate bicistronic transcripts that function in animal cells. Recently IRES elements have also been identified in a small number of vertebrate, insect and yeast cellular messenger RNAs although no such sequences have been identified in endogenous plant genes and there are no reports of animal virus derived IRES activity in plant cells. Here we have constructed a bicistronic gene containing both green fluorescent protein and luciferase open-reading frames separated by the encephalomyocarditis IRES element under the control of the CaMV 35S promoter. Northern analysis reveals expression of the bicistronic transcript and in vivo imaging of GFP and luciferase activities demonstrates the functional presence of both proteins. Western blot analysis confirms the independent translation of both reporter proteins. These data suggest that insertion of the encephalomyocarditis virus (EMCV) IRES element between two open-reading frames of a plant bicistronic transcript can mediate translation of the second open-reading frame. This activity is more apparent in the leaves, than in the roots, of transgenic seedlings carrying the bicistronic reporter gene construct.

A microcalorimetric method for studying the biological effects of La(3+) on Escherichia coli

A microcalorimetric technique based on the bacterial heat-output was explored to evaluate the stimulatory effect of La(3+) on Escherichia coli. The power-time curves of the growth metabolism of E. coli and the effect of La(3+) on it were studied using an LKB-2277 BioActivity Monitor, stopped-flow method, at 37 degrees C. For evaluation of the results, the maximum power (P(max)), the growth rate constants (k) and the heat effects (Q(LOG), Q(STAT)) for the log phase, the stationary phase and the total heat effect (Q(T)) for E. coli were determined. The microcalorimetric method agreed with the conventional methods, such as cell numbers and biomass. La(3+) in the concentration ranges of 0-400 microg/ml has stimulatory effects on E. coli, while La(3+) ion of higher concentrations (>400 microg/ml) can inhibit the growth. This phenomenon is very similar to those observed from the in vitro cells and tissues from animals, plants and some microorganisms by other methods.

Microcalorimetric investigation of the toxic action of Cd(2+) on Rhizopus nigricans growth

The microcalorimetric bioassay for acute cellular toxicity is based on metabolic heat production from cultured cells. Microcalorimetry is a quantitative, inexpensive, and versatile method for toxicology research. The biological response to toxicants is the inhibition of the heat production rate in cells and toxicity is expressed as the concentration of toxicant that is 50% effective in this inhibition (IC(50)). In this paper, the effect of Cd(2+) on Rhizopus nigricans growth was investigated at 25 degrees C. The relationship between growth rate constants (k) and concentration of Cd(2+) (C) shows a logarithmic normal distribution, and described as k=1. 2742x10(61)exp[-1.810x10(-3)(C+283.0)(2)], and IC(50) is 0.72 microg/ml. These signals are readily obtained by an LKB 2277-204 heat conduction microcalorimeter.

Properties of cyanovirin-N (CV-N): inactivation of HIV-1 by sessile cyanovirin-N (sCV-N)

Cyanovirin-N (CV-N) is a novel anti-HIV protein isolated and characterized from a cyanobacterium Nostoc ellipsosporum. CV-N protein is a single 101 amino acid chain containing two intrachain disulphide bonds and considerable internal sequence duplication, but no significant homology to previously described proteins or to the transcription products of known nucleotide sequences. In solution, CV-N exists largely as a beta-sheet protein with internal two-fold pseudosymmetry. CV-N irreversibly inactivates diverse laboratory strains, primary isolates and clades of HIV-1, as well as strains of HIV-2 and simian immunodeficiency virus (SIV). CV-N binds with extremely high affinity to highly conserved binding site(s) on the viral envelope glycoprotein gp120, preventing virus-to-cell fusion, viral entry and infection of cells. The CV-N binding site appears to overlap, but is not identical with, the unique carbohydrate-dependent epitope 2G12, and may lie predominantly within an immunologically "silent" region of gp120. CV-N is undergoing preclinical development for topical anti-HIV prophylactic (e.g., microbicidal) applications to prevent sexual transmission of HIV. Since CV-N may be immunogenic in humans, methods for using CV-N for ex vivo inactivation of HIV in blood, plasma, or putative vaccines preferably would allow for its exclusion from biologicals for parenteral use. To explore this concept we biotinylated CV-N (bCV-N) and coupled it to streptavidin coated magnetic beads to provide a product which we termed sessile CV-N (sCV-N). When reacted with a laboratory strain and a primary isolate of HIV- 1, the sCV-N completely inactivated 100 TCID50 of the virus. However RT-PCR of the viral extracts indicated that only a fraction of the virus was removed by the sCV-N, leaving behind a relatively larger fraction of non-infectious virus in the supernatant which we designated as replication incompetent virions (RIV). It would be worthwhile investigating the role of RIV as a putative HIV vaccine.

Microcalorimetric studies on the metabolism of Chlorella vulgaris

The heat output of the non-growth metabolism of Chlorella vulgaris has been determined using an LKB-2277 BioActivity Monitor. The experimental results indicate that there is a turn-point on the metabolic thermogenic curves, which can be divided into two parts, an early phase and a later phase. For the early phase, there is a linear relationship between the metabolic power (P) and the cell concentration (C), and that the heat output produced by a single cell's metabolism (P0) depends on the cell concentration (C) and is inhibited by the cell density, the thermokinetic equation of their metabolism is dP/dt = k0, k0 = 0.

Microcalorimetric studies of the toxic action of La3+ in mitochondria isolated from Star-cross 288 chicken heart tissue cells

The thermogenic curves of the metabolism of mitochondria isolated from the heart of chicken Star-cross 288 and the effect of La3+ on it were studied by using an LKB-2277 BioActivity Monitor, ampoule method, at 37 degrees C. After isolation from the chicken heart tissue, mitochondria still have metabolic activity and can live for a long time by using the stored nutrients. From the thermogenic curves, we obtained the thermokinetic equations under different conditions. The kinetics show that La3+ has changed the metabolism completely.

Treatment of human breast cancer cells with antisense RNA to the type I insulin-like growth factor receptor inhibits cell growth, suppresses tumorigenesis, alters the metastatic potential, and prolongs survival in vivo

The type I insulin-like growth factor receptor (IGF-IR) plays an important role in the growth and transformation of breast cancer cells. In this study, we investigated the effects of treatment with an antisense IGF-IR construct on cells from the highly metastatic estrogen receptor-negative human breast cancer cell line MDA-MB-435s. The cells carrying the antisense IGF-IR had a markedly reduced expression of IGF-IR, had a significant decrease in cell proliferation, and lost the ability to form colonies in soft agar. There was a delay in tumor formation and a dramatic reduction in tumor size when cells carrying the antisense IGF-IR were injected into either nude or severe combined immunodeficient (scid) beige mice. We have also provided data that show that the scid beige mouse is a more suitable model for studying metastasis of the MDA-MB-435s cells. All of the scid beige mice injected with cells carrying the control construct had metastasis to the lungs, whereas lungs from the nude mice had no apparent metastatic sites after 11 weeks. When cells carrying antisense IGF-IR were injected subcutaneously in scid beige mice, the animals had a significant increase in survival compared with mice injected with cells carrying the control construct. Taken together, these results indicate that the IGF-IR can play a critical role in the progression of breast cancer. Our studies provide a basis for the development of future treatment strategies targeting the IGF-IR in metastatic breast cancer.

Cloning and sequencing of the fragment of angiostatin K (1-3) gene

OBJECTIVE

To secure anti-endotheliocyte hyperplasia functional fragment of human angiostatin K (1-3) gene.

METHODS

As the template of leukocytotic cDNA, functional fragment of human angiostatin K (1-3) cDNA was amplified by PCR, cloned into the vector pGEM-3Zf, and sequenced according to Dye primer sequencing kit.

RESULTS

The functional fragment of angiostatin K (1-3) cDNA (859 bp) was obtained by PCR and determined by sequencing.

CONCLUSION

The angiostatin K (1-3) gene has been cloned. The gene is of great significance in tumor-antiangiogenesis therapy.

Cellular proliferation potential during aging and caloric restriction in rhesus monkeys (Macaca mulatta)

Caloric restriction (CR) is the most successful method of extending both median and maximal lifespans in rodents and other short-lived species. It is not yet clear whether this method of life extension will be successful in longer-lived species, possibly including humans; however, trials in rhesus monkeys are underway. We have examined the cellular proliferative potential of cells from CR and AL (ad libitum fed) monkey skin cells using two different bioassays: colony size analysis (CSA) of dermal fibroblasts isolated and cloned directly from the skin and beta-galactosidase staining at pH 6.0 (BG-6.0) of epidermal cells in frozen sections of skin. Decreases in both proliferative markers occurred with age, but no differences were observed between CR and AL animals. Skin biopsies were obtained from AL and CR rhesus monkeys from two different aging colonies, one at the National Institute on Aging (NIA) and one at the University of Maryland-Baltimore (UMB). These biopsies were used as a source of tissue sections and cells for two biomarkers of aging assays. The CR monkeys had been maintained for 9-12 years on approximately 70% of the caloric intake of control AL animals. In the CSA studies, the fraction of small clones increased significantly and the fraction of large clones decreased significantly with increasing age in AL monkeys. The frequency of epidermal BG-6.0 staining cells increased with age in older (>22 years) AL monkeys, but most predominately in those of the UMB colony, which were somewhat heavier than the NIH AL controls. Old monkeys on CR tended to have fewer BG-6.0-positive cells relative to old AL-derived epidermis, but this effect was not significant. These results indicate that cellular proliferative potential declined with age in Macaca mulatta, but was not significantly altered by CR under these conditions. Although these experiments are consistent with an absence of effect of CR on monkey skin cell proliferative potential, we have found in previous experiments with mice that a longer duration of CR (as a fraction of total lifespan) was needed to demonstrate CR-related improvement in clone size in mice. Further studies on the now mid-aged monkeys will be needed as their age exceeds 20 years to conclusively rule out an effect of CR on proliferative potential of skin cells from these primates.

Thermochemical studies of the toxic actions of heavy metal ions on Rhizopus nigricans

By using a LKB2277 BioActivity Monitor (heat conduction microcalorimeter), stopped-flow method, the thermogenetic curves of Rhizopus nigricans growth at 25 degrees C inhibited by four kinds of heavy metal ions are determined, parameters such as growth rate constants k, inhibitory ratio I, half inhibitory concentration IC50 et al. are obtained. The experimental results show that heavy metal ions can inhibit Rhizopus nigricans growth obviously, low concentration of Cu2+ has promoting action. The inhibitory sequence is Cd2+ > Hg2+ > Pb2+ > Cu2+, half inhibitory concentration of them are Cd+ 0.8 micro g x ml(-1), Hg2+ 1.7 micro g x ml(-1), Pb2+ 48.0 micro g x ml(-1), Cu2+ 110 micro g x ml(-1). This microclorimetric bioassay for acute cellular toxicity is based on metabolic heat evolution from cultured cells. The assay is quantitative, inexpensive, and versatile; moreover, toxicological information can be obtained with cell from other species of interest.

2,2',6,6'-Tetrachlorobiphenyl is estrogenic in vitro and in vivo

Polychlorinated biphenyls (PCBs) are ubiquitous environmental contaminants whose effects on biological systems depend on the number of and the positions of the chlorine substitutions. In the present study we examined the estrogenicity of the fully ortho-substituted PCB, 2,2',6,6'-tetrachlorobiphenyl (2,2',6,6'-TeCB). This PCB was chosen as the prototypical ortho-substituted PCB to test the hypothesis that ortho-substitution of a PCB with no para- or meta-chlorine-substitutions results in enhanced estrogenic activity. The results indicate that 2,2',6,6'-TeCB is estrogenic both in vitro, in the MCF-7 cell focus assay, and in vivo, in the rat uterotropic assay. The estrogenic activity elicited by the addition of 5 microM 2,2',6,6'-TeCB to the medium of MCF-7 cultures was inhibited by the estrogen receptor (ER) antagonist, LY156758, suggesting that 2,2',6,6'-TeCB or a metabolite is acting through an ER-dependent mechanism. Results from competitive binding assays using recombinant human (rh) ER indicate that 2,2',6,6'-TeCB does not bind rhERalpha or rhERbeta. A metabolite of 2,2',6,6'-TeCB, 2,2',6,6'-tetrachloro-4-biphenylol (4-OH-2,6,2',6'-TCB), does bind rhERalpha and rhERbeta and is also 10-fold more estrogenic than 2,2',6,6'-TeCB in the MCF-7 focus assay; however, this metabolite is not detected in the medium of MCF-7 cultures exposed to 2,2',6,6'-TeCB. Taken together, the results suggest that the estrogenicity observed in human breast cancer cells and the rat uterus may be due to 1) an undetected metabolite of 2,2',6,6'-TeCB binding to the ER, 2) 2,2',6,6'-TeCB binding directly to a novel form of the ER, or 3) an unknown mechanism involving the ER.

Measuring exposure to S. japonicum in China. II. Activity diaries, pathways to infection and immunological correlates

In this study we examine the pathways to schistosomiasis exposure and infection among residents residing on two islands (large, Qingshan; small, Niangashan) in the Dongting Lake region (Hunan province) of China. An exposure model, based on activity diaries, was used to quantify an individual's square-metre-minute (sq.m.min) daily water contact. Subjects living on the small island had a significantly higher (P=0.0002) degree of exposure (mean+/-S.D., 13.2+/-11.0 sq.m.min) than individuals dwelling on the large island (mean+/-S.D., 5.5+/-7.1 sq.m.min). Participants identified as stool egg positive (mean+/-S.D., 8.3+/-10.4 sq.m.min) had higher exposures than for those never treated (mean+/-S.D., 2.2+/-3.4 sq.m.min) for schistosomiasis, and these high exposures rose steadily to peak at 35-49 years of age and decline after age 50. This exposure pattern differs markedly from those reported for African or South American schistosomiasis. The majority of human water contact occurs on the lake. Egg-positive subjects reported significantly higher (P < 0.05) episodes of water contact on the lake versus their egg-negative counterparts, who reported significantly higher (P < 0.01) exposure at the aquaculture ponds. The results of path analysis revealed that sex, age, island of residence and whether a fisherman or not were the most highly significant independent predictors of lake exposure. This accounted for approximately 40% (R2=0.39) of the total lake exposure. Exposure to lake water was a strong predictor (P=0.0006) of past infection and a modest predictor (P=0.05) of current infection.

Measuring exposure to S. japonicum in China. I. Activity diaries to assess water contact and comparison to other measures

We introduce a new method, activity diaries, in order to evaluate human water contact among fishing communities in an area moderately endemic for Schistosoma japonicum in the Dongting Lake region of Southern China. Two hundred and forty-nine subjects (76% male) were followed prospectively over a 9-month-period in order to verify exposure and reinfection. Exposure was determined crudely with questionnaires, direct 12-h water observations, and more precisely with activity diaries and an adjusted exposure model which took into account the time of day, the duration of contact and the percent body surface area in contact with water. Cohort subjects filled in activity diaries for an average of 85 days as compared with 2 days for the direct water observations. The typical unadjusted mean daily water contact (duration) based on the activity diaries was 53 min with 62% of this time spent in fishing. In contrast, the direct water observations revealed an average daily duration of 149 min with 53% of the time spent in fishing. Human water contact patterns (min/day) by site, activity and body part exposed were examined with the activity diaries. Individuals in the 36-49-year-old age range had the highest degree of water contact. Most of this daily contact occurred by males on the hands (mean+/-S.D.; 83.53+/-67.80 min/day) while fishing (mean+/-S.D.; 87.84+/-8.88 min/day) on the lake (mean+/-S.D.; 85.98+/-69.90 min/day). There was a strong positive log correlation (r=0.95) between the crude and adjusted (based on our derived exposure model) diary outcomes for the entire study sample, however, at higher exposure levels this relationship was differentially weaker (r=0.70). Results from this study suggest that current methods used in evaluating schistosomiasis exposure in China may overestimate and bias measures of the risk of infection. Activity diaries adjusted for the time of day, duration and the percent body surface area exposed are cost-effective and practical instruments to accurately quantify human exposure in the vast lake regions of Southern China where most of the endemic schistosomiasis japonica occurs.

One-stage open cancellous bone grafting of infected fracture and nonunion

Nineteen patients with either infected fractures or nonunions were managed by a one-stage protocol consisting of thorough debridement of the septic focus, followed by stabilization with an external fixator or a cast and fresh autogenous cancellous bone grafting; the wound was then left open. Nineteen fractures were healed and free of infection at an average of 3.5 years follow-up. Some considerations, including debridement, stabilization, bone grafting, and wound coverage, are discussed.

Epidemiologic features of Schistosoma japonicum among fishermen and other occupational groups in the Dongting Lake region (Hunan Province) of China

In this study we examined 1,909 individuals (53% males and 47% females) to determine the current status of Schistosoma japonicum among the people in five fishing villages situated on two islands (large, Qingshan island; small, Niangashan island) in the Dongting Lake region in Hunan Province, the People's Republic of China. The results of this study indicate that the overall prevalence for schistosomiasis on the two islands is 16%. Two distinct peaks in prevalence (29%) were observed at 25-35 years of age and again at 45-55 years of age for both the large and small islands. On the small island the overall prevalence (24%) varied significantly (P < 0.01) from the large island (15%). Fishermen had the highest prevalence (22.4%) among all the occupational groups examined but students produced the highest worm intensity (geometric mean = 69 eggs per gram [epg] of feces). There was a significant difference (P < 0.01) in the prevalence of schistosomiasis between males and females. In general, males had a much higher prevalence (22%) than females (8.9%). When the study populations were classified as uninfected, lightly infected (10-100 epg), moderately infected (101-400 epg), and heavily infected (> 401 epg) with S. japonicum, the distribution pattern was similar for each of the five villages. The majority (76-88%) of the population remains uninfected. Lightly infected individuals had the highest prevalence (7-12%) followed by moderately infected individuals (1-9%). Only a very small percentage of the population was heavily infected (0-2%). Hepatomegaly along the midsternal line (MSL > or = 3) was commonly seen in both uninfected (21%) and infected individuals (1939%). Subjects heavily infected with S. japonicum reported significantly higher (P < 0.05) cases of liver enlargement when compared with those uninfected. The reported cases of abdominal pain for both uninfected (9%) and infected individuals (4-19%) was relatively high. Lightly and moderately infected individuals reported significantly (P < 0.05 and P < 0.01, respectively) more episodes of abdominal pain than those uninfected. The occurrence of diarrhea was low (5%) for uninfected individuals but this clinical feature was significantly (P < 0.01) more prevalent in both the lightly and heavily infected categories (8-17%).

[Clinical research of nipple-areola preserved mastectomy and one-stage breast reconstruction with rectus abdominis musculocutaneous flaps]

OBJECTIVE

To discuss the method for nipple-areola preserved mastectomy with one-stage breast reconstruction in cancer surgery.

METHODS

Because of the merits of sufficient blood supply and plasticity of rectus abdominis musculocutaneous flap, we used one-stage breast reconstruction after modified radical mastectomy. The incision line was covered and the nipple-areola was preserved. The reconstructed breast was naturally in contour.

RESULTS

21 cases were treated from 1990 to 1995, and 18 of them received horizontal-rhombus shaped rectus abdominis musculocutaneous flaps and 3 longitudinal-rhombus flaps for breast reconstruction. Nipple-areola was preserved in 16 cases. Objective evaluation after operation showed that the excellent and satisfied rate reached to 90.5%; and subjective evaluation showed that the excellent and satisfied rate reached to 95.2%. Thirteen cases have been followed up for 3 years, and 9 for 5 years. Three-year survival rate was 100% (13/13), and 5-year 88.9% (8/9).

CONCLUSION

The method is recommendable for the treatment of stage I-II breast cancer.

A triphenylboroxin derivative possessing two intramolecular chelates

Condensation of 2-formylbenzeneboronic acid and 1,1-dimethylhydrazine afforded the title compound, bis(8-B-4)-1,3,5-tris[2-[(N,N-dimethylhydrazono)methyl]-phenyl)]b oroxin, C27H33B3N6O3, a tridehydro cyclic trimer of the expected simple benzaldehyde hydrazone and the first triphenylboroxin derivative found to possess two B chelating interactions. The double chelation induces molecular asymmetry but effects only a slight puckering in the central boroxin ring.

PSK protects macrophages from lipoperoxide accumulation and foam cell formation caused by oxidatively modified low-density lipoprotein

In previous works, it has been evidenced that lipoperoxidative injury to macrophages caused by oxidatively modified low-density lipoprotein (O-LDL) plays an important role in foam cell formation, and that PSK, a protein bound polysaccharide extracted from the class Basidiomycetes Coriolus Versicolor, can protect macrophages from lipoperoxidative injury induced by tert-butyl hydroperoxide (tbOOH). In this paper PSK protection of macrophages from lipoperoxide (LPO) accumulation and foam cell formation caused by O-LDL and its action mechanism were further studied. The LPO accumulation was determined by using ACAS 570. Dynamic assay of the LPO level in eight single cells after adding O-LDL or determination of the average LPO content in a lot of cells incubated in advance with O-LDL for 12 h, both indicated that O-LDL might induce LPO accumulation in macrophages and the effects of O-LDL could be prevented by PSK. O-LDL might cause the changes of morphological structure in macrophages and the transformation of macrophages into foam cells, and the effects could also be prevented by PSK. The determination of selenium-dependent glutathione peroxidase (SeGSHPx) activities and mRNA contents of macrophages and changes of SeGSHPx activity and mRNA content after incubation with tbOOH showed that PSK might increase the SeGSHPx activity of macrophage and the enhanced SeGSHPx activity may occur at the level of gene transcription.