Osteogenesis in extraskeletally implanted porous calcium phosphate ceramics: variability among different kinds of animals

Synthetic porous calcium phosphate ceramics (HA/TCP) were implanted intramuscularly and subcutaneously in dogs, pigs, goats, rabbits and rats, designed to make a comparative study of the host tissue responses to porous HA/TCP ceramics in different kinds of animals. Specimens were harvested at 15, 30, 45, 60, 90 and 120 days after implantation. Decalcified and undecalcified sections were made and examined by light microscopy. Obvious bone formation could be detected in some specimens harvested from dogs and pigs after 45 days intramuscular implantation or after 60 days subcutaneous implantation. At days 90 and 120, an extensive amount of bone formed in all specimens implanted in dogs and pigs. However, no histologically detectable bone formation was observed in any specimen implanted intramuscularly and subcutaneously in goats, rabbits and rats until 120 days. It is demonstrated from this finding that the synthetic porous calcium phosphate ceramics are capable of inducing osteogenesis when implanted in non-bony sites, but this ability varies between different kinds of animals. Earlier periods of observation in specimens harvested from dogs showed that bone differentiation in the pore regions of the ceramics follows a complex process involving invasion of the fibrovascular connective tissues at day 15, appearance of polymorphic mesenchymal cells near the invading vasculature and at the interface with the ceramics at day 30, differentiation of osteoblasts and formation of bone matrix in direct contact with the surface of the ceramics at day 45, and finally remodelling of the fibrous connective tissue into an extensive amount of bone at days 60, 90 and 120.

Role of p38 MAP kinases and ERK in mediating ultraviolet-B induced cyclooxygenase-2 gene expression in human keratinocytes

The roles of p38 MAP kinases and ERK in UVB induced cox-2 gene expression were studied in a human keratinocyte cell line, HaCaT. UVB significantly increased cox-2 gene expression at both protein and mRNA levels. As we reported previously, p38 and ERK were significantly activated after UVB irradiation in HaCaT cells. In addition, treating the cells with p38 inhibitor SB202190 or MEK inhibitor PD98059 specifically inhibited UVB induced p38 or ERK activation, respectively. In this study, we further examined the roles of p38 and ERK in UVB induced cox-2 gene expression in HaCaT cells. We found that SB202190 strongly inhibited UVB induced COX-2 protein expression at different time points and various UVB doses. Furthermore, SB202190 markedly inhibited UVB induced cox-2 mRNA. Our data indicated that ERK did not play a role in UVB induced cox-2 gene expression in human keratinocytes since suppression of ERK did not significantly alter UVB induced increase of COX-2 protein and mRNA. These results suggested, for the first time, that activation of p38 is required for UVB induced cox-2 gene expression in human keratinocytes. Since cox-2 expression plays an important role in UV carcinogenesis, p38 could be a potential molecular target for chemoprevention of skin cancer.

A colorimetric assay for measuring activation of Gs- and Gq-coupled signaling pathways

Current assays for functional activation of Gs-coupled receptors usually involve quantitation of adenylyl cyclase or measurement of cAMP concentration by radioimmunoassay. The activation of Gq-coupled receptors is commonly assayed by measurement of the production of inositol triphosphate or diacylglycerol from phosphatidylinositol 4,5-bisphosphate or of changes in intracellular calcium. These assays generally require large numbers of cells (10(5)-10(6)) and/or the use of radioactive materials. We have developed a rapid nonradioactive colorimetric assay that utilizes a beta-galactosidase (lacZ) gene fused to five copies of the cyclic AMP response element (CRE) to detect the activation of CRE-binding protein that results from an increase in intracellular cAMP or calcium. This assay can be performed using as few as 30,000 cells in a 96-well format with the end products measured simultaneously in a microplate reader. Consequently, a single individual can readily assay 1000 samples a day. Using this assay, the fold increase in beta-galactosidase activity was similar in magnitude to increases in cAMP or adenylyl cyclase activity and was approximately linear from 0.01 to 0.27 fmol/cell of intracellular cAMP. Furthermore, pharmacological characterization of one of the melanocortin receptors, mMC5-R, using this assay resulted in a similar order of potency for several melanocortin peptides to that obtained with a commonly used adenylyl cyclase enzyme assay. This assay is also useful for the characterization of Gq-coupled receptors as is demonstrated here using cells transfected with the mouse bombesin receptor. The large-scale capacity of this assay makes it an excellent method for screening molecules of interest acting on Gs- and Gq-coupled receptors.

Oxidation of acetaminophen to its toxic quinone imine and nontoxic catechol metabolites by baculovirus-expressed and purified human cytochromes P450 2E1 and 2A6

Acetaminophen (APAP), a widely used analgesic and antipyretic agent, is bioactivated by cytochromes P450 to cause severe hepatotoxicity. APAP is oxidized by two pathways to form a toxic intermediate, N-acetyl-p-benzoquinone imine (NAPQI), and a nontoxic catechol metabolite, 3-hydroxy-APAP (3-OH-APAP). We investigated the role of P450 2E1 and 2A6 in APAP oxidation by using baculovirus-expressed and highly purified forms of human P450 2E1 and 2A6. An electrochemical HPLC assay was developed to quantify both oxidative metabolites simultaneously. For the first time, it was demonstrated that human P450 2E1 selectively oxidized APAP to NAPQI (assayed as its glutathione conjugate, GS-APAP), whereas human P450 2A6 selectively oxidized APAP to 3-OH-APAP. At 1 mM APAP, the relative ratio for the formation of GS-APAP vs 3-OH-APAP with human P450 2E1 was approximately 6:1, whereas the ratio with human P450 2A6 was 1:3. Apparent Km and Vmax values for the formation of GS-APAP by human P450 2E1 were 1.3 mM and 6.9 nmol/min/nmol of P450, respectively, whereas they were 4.6 mM and 7.9 nmol/min/nmol of P450 for P450 2A6. Apparent Km and Vmax values for the formation of 3-OH-APAP by human P450 2E1 were 4.0 mM and 2.5 nmol/min/nmol of P450, respectively, whereas they were 2.2 mM and 14.2 nmol/min/nmol of P450, respectively, for P450 2A6. Thus, although at toxic doses of APAP P450 2E1 is the more efficient catalyst for the formation of the toxic metabolite NAPQI, P450 2A6 also can contribute significantly to NAPQI production.

Inhibition of endothelial cell migration by cerivastatin, an HMG-CoA reductase inhibitor: contribution to its anti-angiogenic effect

Recent studies have suggested that inhibitors of 3-hydroxy-3-methyl-glutaryl-coenzyme A reductase (statins) can play a role in protection against vascular risk, which is independent of cholesterol reduction. It could act by inhibiting the synthesis of isoprenoids (farnesylpyrophosphate (FPP) and geranylgeranylpyrophosphate (GGPP)), which are respectively essential for membrane attachment and biological activity of GTPases Ras and RhoA. This study demonstrates that a statin (cerivastatin) inhibits angiogenesis. This effect was due to a decrease in endothelial cell locomotion which was reversed by GGPP. It was mainly related to delocalization of RhoA from cell membrane to cytoplasm, responsible for the disorganization of actin stress fibers. Furthermore, a decrease in MMP-2 secretion, involved in cell invasion, was also observed. This effect is rather due to Ras inhibition as it was reversed by FPP. This anti-angiogenic activity could explain the beneficial effect of statins on atherosclerosis and on cancer prevention as shown by clinical studies.

Biosensor for direct determination of organophosphate nerve agents. 1. Potentiometric enzyme electrode

A potentiometric enzyme electrode for the direct measurement of organophosphate (OP) nerve agents was developed. The basic element of this enzyme electrode was a pH electrode modified with an immobilized organophosphorus hydrolase (OPH) layer formed by cross-linking OPH with bovine serum albumin (BSA) and glutaradehyde. OPH catalyses the hydrolysis of organophosphorus pesticides to release protons, the concentration of which is proportional to the amount of hydrolysed substrate. The sensor signal and response time was optimized with respect to the buffer pH, ionic concentration of buffer, temperature, and units of OPH immobilized using paraoxon as substrate. The best sensitivity and response time were obtained using a sensor constructed with 500 IU of OPH and operating in pH 8.5, 1 mM HEPES buffer. Using these conditions, the biosensor was used to measure as low as 2 microM of paraoxon, ethyl parathion, methyl parathion and diazinon. The biosensor was completely stable for at least one month when stored in pH 8.5, 1 mM HEPES + 100 mM NaCl buffer at 4 degrees C.

Osseous substance formation induced in porous calcium phosphate ceramics in soft tissues

Porous calcium phosphate ceramics prepared according to the methods of laboratories in Leiden were implanted subcutaneously in rats for 3, 6 and 12 w. No bone formation could be observed. Porous calcium phosphate ceramics prepared according to the methods of laboratories in Sichuan were implanted subcutaneously/intramuscularly in dogs for 1, 3, 5 and 7 months. In particular, ceramics containing alpha-tricalcium phosphate evoked bone formation in the pores of the ceramics. The amount of bone was similar at the different time periods.

Synectin, syndecan-4 cytoplasmic domain binding PDZ protein, inhibits cell migration

Syndecan-4, a member of the syndecan gene family of proteoglycans, is an important regulator of bFGF signaling. In particular, bFGF-dependent regulation of cell growth and migration has been linked to syndecan-4 cytoplasmic domain-mediated interactions. Screening of a yeast two-hybrid library with a cytoplasmic domain of rat syndecan-4 identified a novel binding partner, here termed synectin. Synectin is highly homologous to semaphorin F binding protein semcap1, glucose 1 transporter binding protein glut1cbp, and RGS-GAIP/neuropilin-1 binding protein GIPC. Overexpression of synectin in ECV304 cells in culture led to a dose-dependent inhibition of migration while not affecting cell adhesion or growth rate. We conclude that synectin is involved in syndecan-4-dependent interactions and may play a role in the assembly of syndecan-4 signaling complex.

Human cytochrome P450 2E1 is a major autoantigen associated with halothane hepatitis

Autoantibodies against specific human cytochrome P450s have been found in the sera of patients suffering from a variety of diseases, including those caused by drugs. In the cases of tienilic acid- and dihydralazine-induced hepatitis, patients have serum autoantibodies directed against cytochromes P450 2C9 and P450 1A2, respectively. In the present study, we have found that 25 of 56 (45%) patients diagnosed with halothane hepatitis have autoantibodies that react with human cytochrome P450 2E1 that was purified from a baculovirus expression system. The autoantibodies inhibited the activity of cytochrome P450 2E1 and appeared to be directed against mainly conformational epitopes. In addition, because cytochrome P450 2E1 became trifluoroacetylated when it oxidatively metabolized halothane, it is possible that the covalently altered form of cytochrome P450 2E1 may be able to bypass the immunologic tolerance that normally exists against cytochrome P450 2E1. A similar mechanism may explain the formation of autoantibodies that have been found against other cellular targets of the reactive trifluoroacetyl chloride metabolite of halothane.

Synthesis, chromatographic resolution, and anti-human immunodeficiency virus activity of (+/-)-calanolide A and its enantiomers

The anti-HIV agent (+/-)-calanolide A (1) has been synthesized in a five-step approach starting with phloroglucinol [-->5-->6-->11-->18-->(+/-)-1], which includes Pechmann reaction, Friedel-Crafts acylation, chromenylation with 4,4-dimethoxy-2-methylbutan-2-ol, cyclization, and Luche reduction. Cyclization of chromene 11 to chromanone 18 was achieved by employing either acetaldehyde diethyl acetal or paraldehyde in the presence of trifluoroacetic acid and pyridine or PPTS. Luche reduction of chromanone 18 at lower temperature preferably yielded (+/-)-1. Reduction of chromone 12, synthesized by Kostanecki-Robinson reaction from chromene 11, failed to afford (+/-)-1. The synthetic (+/-)-1 has been chromatographically resolved into its optically active forms, (+)- and (-)-1. The anti-HIV activities for synthetic (+/-)-1, as well as resultant (+)- and (-)-1, have been determined. Only (+)-1 accounted for anti-HIV activity, which was similar to the data reported for the natural product, and (-)-1 was inactive.

Biosensor for direct determination of organophosphate nerve agents using recombinant Escherichia coli with surface-expressed organophosphorus hydrolase. 1. Potentiometric microbial electrode

A potentiometric microbial biosensor for the direct measurement of organophosphate (OP) nerve agents was developed by modifying a pH electrode with an immobilized layer of Escherichia coli cells expressing organophosphorus hydrolase (OPH) on the cell surface. OPH catalyzes the hydrolysis of organophosporus pesticides to release protons, the concentration of which is proportional to the amount of hydrolyzed substrate. The sensor signal and response time were optimized with respect to the buffer pH, ionic concentration of buffer, temperature, and weight of cells immobilized using paraoxon as substrate. The best sensitivity and response time were obtained using a sensor constructed with 2.5 mg of cells and operating in pH 8.5, 1 mM HEPES buffer. Using these conditions, the biosensor was used to measure as low as 2 microM of paraoxon, methyl parathion, and diazinon. The biosensor had very good storage and multiple use stability. The use of cells with the metabolic enzyme expressed on cell surface as a biological transducer provides advantages of no resistances to mass transport of the analyte and product across the cell membrane and low cost due to elimination of enzyme purification, over the conventional microbial biosensors based on cells expressing enzyme intracellularly and enzyme-based sensors, respectively.

Infected cell protein (ICP)47 enhances herpes simplex virus neurovirulence by blocking the CD8+ T cell response

The herpes simplex virus (HSV) infected cell protein (ICP)47 blocks CD8+ T cell recognition of infected cells by inhibiting the transporter associated with antigen presentation (TAP). In vivo, HSV-1 replicates in two distinct tissues: in epithelial mucosa or epidermis, where the virus enters sensory neurons; and in the peripheral and central nervous system, where acute and subsequently latent infections occur. Here, we show that an HSV-1 ICP47- mutant is less neurovirulent than wild-type HSV-1 in mice, but replicates normally in epithelial tissues. The reduced neurovirulence of the ICP47- mutant was due to a protective CD8+ T cell response. When compared with wild-type virus, the ICP47- mutant expressed reduced neurovirulence in immunologically normal mice, and T cell-deficient nude mice after reconstitution with CD8+ T cells. However, the ICP47- mutant exhibited normal neurovirulence in mice that were acutely depleted of CD8+ T cells, and in nude mice that were not reconstituted, or were reconstituted with CD4+ T cells. In contrast, CD8+ T cell depletion did not increase the neurovirulence of an unrelated, attenuated HSV-1 glycoprotein (g)E- mutant. ICP47 is the first viral protein shown to influence neurovirulence by inhibiting CD8+ T cell protection.

Production of tumor necrosis factor/cachectin by human B cell lines and tonsillar B cells

The production of TNF/cachectin by human B cell lines and tonsillar B cells was examined. Of the 15 B cell lines examined, 9 cell lines synthesize TNF mRNA constitutively. PMA stimulated most cell lines to accumulate increased amounts of TNF. SeD, 8866P, 32al, RPMI 1788, and four bone marrow-derived EBV-transformed cell lines accumulated high levels of TNF mRNA when stimulated by PMA. TNF production by these cell lines was examined. RPMI 1788 and WIH8 produced little TNF constitutively, but synthesized 5-7 ng/ml TNF when stimulated by PMA. A pre-B cell line, Nalm-6, did not synthesize any detectable amount of TNF mRNA, even with PMA stimulation. Tonsillar B cells could also be stimulated to produce TNF. PMA or Staphylococcus aureus Cowan I strain (SAC) alone stimulated some TNF mRNA accumulation, whereas B cell growth factor (BCGF) or anti-mu did not. This accumulation was synergistically elevated by the combinations of PMA and SAC, or PMA and anti-mu. BCGF increased PMA-, SAC-, PMA plus SAC-, or PMA plus anti-mu-induced TNF mRNA accumulations about twofold. The accumulation of TNF mRNA in tonsillar B cells stimulated by PMA plus SAC was between 32 and 48 h, the same peak interval as the accumulation of TNF and IL-2 mRNA in tonsillar T cells. This is in contrast to PMA or PMA plus A23187-stimulated RPMI 1788 cells in which TNF mRNA accumulation was maximal at 1-2 h. TNF activities found in tonsillar B cell supernatants correlated with the TNF mRNA levels in the cells. However, more TNF activity was found on the second-day than the third-day supernatants, indicating active TNF uptake by the B cells. Cyclosporin A (CsA) inhibited SAC and anti-mu responses in B cells in much the same way as the anti-CD3 responses in T cells. SAC-, PMA plus SAC-, and PMA plus anti-mu-stimulated, but not PMA-stimulated, increases in TNF mRNA accumulations in tonsillar B cells were inhibited by CsA. TNF production seems to increase in parallel with B cell proliferation, but the relationship of these two functions needs to be further examined.

Biocontrol of Listeria monocytogenes and Escherichia coli O157:H7 in meat by using phages immobilized on modified cellulose membranes

The ability of phages to specifically interact with and lyse their host bacteria makes them ideal antibacterial agents. The range of applications of bacteriophage can be extended by their immobilization on inert surfaces. A novel method for the oriented immobilization of bacteriophage has been developed. The method was based on charge differences between the bacteriophage head, which exhibits an overall net negative charge, and the tail fibers, which possess an overall net positive charge. Hence, the head would be more likely to attach to positively charged surfaces, leaving the tails free to capture and lyse bacteria. Cellulose membranes modified so that they had a positive surface charge were used as the support for phage immobilization. It was established that the number of infective phages immobilized on the positively charged cellulose membranes was significantly higher than that on unmodified membranes. Cocktails of phages active against Listeria or Escherichia coli immobilized on these membranes were shown to effectively control the growth of L. monocytogenes and E. coli O157:H7 in ready-to-eat and raw meat, respectively, under different storage temperatures and packaging conditions. The phage storage stability was investigated to further extend their industrial applications. It was shown that lyophilization can be used as a phage-drying method to maintain their infectivity on the newly developed bioactive materials. In conclusion, utilizing the charge difference between phage heads and tails provided a simple technique for oriented immobilization applicable to a wide range of phages and allowed the retention of infectivity.

Tumor localization of anti-CEA single-chain Fvs: improved targeting by non-covalent dimers

BACKGROUND

Genetic engineering can produce novel antibody fragments with improved properties for applications such as tumor targeting in vivo.

OBJECTIVES

To produce stable monomeric (27 kDa) and dimeric (55 kDa) forms of a single-chain Fv (scFv) from the anti-carcinoembryonic antigen (anti-CEA) antibody T84.66, and assess the targeting and biodistribution properties in an animal model.

STUDY DESIGN

ScFv were constructed with either a 28 or 14 amino acid connecting peptide and expressed by secretion from E. coli. Following affinity purification, proteins were characterized by gel electrophoresis and mass spectrometry. Binding properties were assessed by size exclusion HPLC after incubation with antigen, and affinities determined by surface plasmon resonance. The shorter linker favored formation of dimers (and higher multimers) which showed unusual stability. ScFv were radiolabeled with 125I for tumor targeting and biodistribution studies of monomeric or dimeric forms were conducted in athymic mice bearing LS174T human colorectal carcinoma xenografts.

RESULTS

125I-scFv monomers and dimers targeted exhibited rapid clearance kinetics in tumor-bearing mice. Nevertheless, the anti-CEA scFvs targeted very well to xenografts, leading to high tumor: normal organ ratios (greater than 20:1 at 24 h) for both forms. Tumor localization of the non-covalent dimers was much higher than monomers, reaching 10-15% injected dose per gram at 1 h.

CONCLUSION

Non-covalent dimers of scFv (also known as diabodies) are stable, easy to produce and show excellent targeting as compared to monomeric scFv, probably due to increased mass and valency.

Preferential ATP-binding cassette transporter A1-mediated cholesterol efflux from late endosomes/lysosomes

Recently, ATP-binding cassette transporter A1 (ABCA1), the defective molecule in Tangier disease, has been shown to stimulate phospholipid and cholesterol efflux to apolipoprotein A-I (apoA-I); however, little is known concerning the cellular cholesterol pools that act as the source of cholesterol for ABCA1-mediated efflux. We observed a higher level of isotopic and mass cholesterol efflux from mouse peritoneal macrophages labeled with [(3)H]cholesterol/acetyl low density lipoprotein (where cholesterol accumulates in late endosomes and lysosomes) compared with cells labeled with [(3)H]cholesterol with 10% fetal bovine serum, suggesting that late endosomes/lysosomes act as a preferential source of cholesterol for ABCA1-mediated efflux. Consistent with this idea, macrophages from Niemann-Pick C1 mice that have an inability to exit cholesterol from late endosomes/lysosomes showed a profound defect in cholesterol efflux to apoA-I. In contrast, phospholipid efflux to apoA-I was normal in Niemann-Pick C1 macrophages, as was cholesterol efflux following plasma membrane cholesterol labeling. These results suggest that cholesterol deposited in late endosomes/lysosomes preferentially acts as a source of cholesterol for ABCA1-mediated cholesterol efflux.

Crystal structure of Sar1-GDP at 1.7 A resolution and the role of the NH2 terminus in ER export

The Sar1 GTPase is an essential component of COPII vesicle coats involved in export of cargo from the ER. We report the 1.7-A structure of Sar1 and find that consistent with the sequence divergence of Sar1 from Arf family GTPases, Sar1 is structurally distinct. In particular, we show that the Sar1 NH2 terminus contains two regions: an NH2-terminal extension containing an evolutionary conserved hydrophobic motif that facilitates membrane recruitment and activation by the mammalian Sec12 guanine nucleotide exchange factor, and an alpha1' amphipathic helix that contributes to interaction with the Sec23/24 complex that is responsible for cargo selection during ER export. We propose that the hydrophobic Sar1 NH2-terminal activation/recruitment motif, in conjunction with the alpha1' helix, mediates the initial steps in COPII coat assembly for export from the ER.

Identification of a methylation imprint mark within the mouse Gnas locus

The imprinted mouse gene Gnas produces the G protein alpha-subunit G(S)alpha and several other gene products by using alternative promoters and first exons. G(S)alpha is maternally expressed in some tissues and biallelically expressed in most other tissues, while the gene products NESP55 and XLalphas are maternally and paternally expressed, respectively. We investigated the mechanisms of Gnas imprinting. The G(S)alpha promoter and first exon are not methylated on either allele. A further upstream region (approximately from positions -3400 to -939 relative to the G(S)alpha translational start site) is methylated only on the maternal allele in all adult somatic tissues and in early postimplantation development. Within this region lies a fourth promoter and first exon (exon 1A) that generates paternal-specific mRNAs of unknown function. Exon 1A and G(S)alpha mRNAs have similar expression patterns, making competition between their promoters unlikely. Differential methylation in this region is established during gametogenesis, being present in oocytes and absent in spermatozoa, and is maintained in preimplantation E3. 5d blastocysts. Therefore, this region is a methylation imprint mark. In contrast, differential methylation of the NESP55 and XLalphas promoter regions (Nesp and Gnasxl) is not established during gametogenesis. The methylation imprint mark that we identified may be important for the tissue-specific imprinting of G(S)alpha.

Risk factors for periprosthetic joint infection after total joint arthroplasty: a systematic review and meta-analysis

Many of the mooted risk factors associated with periprosthetic joint infection (PJI) after total joint arthroplasty (TJA) remain controversial and are not well characterized. Online and manual searches were performed using Medline, Embase, Chinese National Knowledge Infrastructure and the Cochrane Central Database from January 1980 to March 2014). For inclusion, studies had to meet the quality assessment criteria of the CONSORT statement, and be concerned with evaluation of risk factors for PJI after TJA. Two reviewers extracted the relevant data independently and any disagreements were resolved by consensus. Fourteen studies were included in this meta-analysis. The following significant risk factors for PJI were identified: body mass index (both continuous and dichotomous variables); diabetes mellitus; corticosteroid therapy; hypoalbuminaemia; history of rheumatoid arthritis; blood transfusion; presence of a wound drain; wound dehiscence; superficial surgical site infection; coagulopathy; malignancy, immunodepression; National Nosocomial Infections Surveillance Score ≥2; other nosocomial infection; prolonged operative time; and previous surgery. Factors that were not significantly associated with PJI were: cirrhosis; hypothyroidism; urinary tract infection; illicit drug abuse; alcohol abuse; hypercholesterolaemia; hypertension, ischaemic heart disease; peptic ulcer disease; hemiplegia or paraplegia; dementia; and operation performed by a staff surgeon (vs a trainee). Strategies to prevent PJI after TJA should focus, in particular, on those patients at greatest risk of infection according to their individual risk factors.

Cappuccino, a Drosophila maternal effect gene required for polarity of the egg and embryo, is related to the vertebrate limb deformity locus

We report the molecular isolation of cappuccino (capu), a gene required for localization of molecular determinants within the developing Drosophila oocyte. The carboxy-terminal half of the capu protein is closely related to that of the vertebrate limb deformity locus, which is known to function in polarity determination in the developing vertebrate limb. In addition, capu shares both a proline-rich region and a 70-amino-acid domain with a number of other genes, two of which also function in pattern formation, the Saccharomyes cerevisiae BNI1 gene and the Aspergillus FigA gene. We also show that capu mutant oocytes have abnormal microtubule distributions and premature microtubule-based cytoplasmic streaming within the oocyte, but that neither the speed nor the timing of the cytoplasmic streaming correlates with the strength of the mutant allele. This suggests that the premature cytoplasmic streaming in capu mutant oocytes does not suffice to explain the patterning defects. By inducing cytoplasmic streaming in wild-type oocytes during mid-oogenesis, we show that premature cytoplasmic streaming can displace staufen protein from the posterior pole, but not gurken mRNA from around the oocyte nucleus.

Importance of endogenous tumor necrosis factor alpha and gamma interferon in host resistance against Pneumocystis carinii infection

C.B-17 scid/scid (SCID) mice that have acquired natural pulmonary infection with Pneumocystis carinii clear these organisms by 19 days after reconstitution with spleen cells from immunocompetent mice and therefore serve as a model for studying the pathogenesis of and immunity to P. carinii pneumonia. The present study examined the importance of endogenous tumor necrosis factor alpha (TNF-alpha) and gamma interferon (IFN-gamma) in the clearance of P. carinii by treatment of reconstituted SCID mice with anti-TNF-alpha and anti-IFN-gamma immunoglobulin G (IgG). Treatment of reconstituted mice with monospecific rabbit anti-TNF-alpha IgG almost completely inhibited the clearance of P. carinii from the lungs. In contrast, treatment with either anti-IFN-gamma antibody (polyclonal or monoclonal) or control IgG had no detectable effect on the clearance of P. carinii. The importance of endogenous TNF-alpha in the clearance of P. carinii was further supported by the finding of TNF-alpha but not IFN-gamma in lung homogenate supernatants from reconstituted SCID mice. Further study revealed that for the complete clearance of P. carinii, TNF-alpha must be present at the early stage of reconstitution, since clearance could be blocked by a single injection of anti-TNF-alpha IgG into SCID mice at day 0 but not at day 6 and/or day 12 after reconstitution. These results strongly suggest that, in reconstituted SCID mice, endogenous TNF-alpha is important in host resistance against P. carinii infection, whereas IFN-gamma appears not to play a significant role.

Influence of consumption of probiotics on the plasma lipid profile: a meta-analysis of randomised controlled trials

AIMS

Human clinical studies have yielded mixed results on the effects of consumption of probiotics on the plasma lipid profile. We conducted a meta-analysis of randomised controlled trials that evaluated the effects of probiotics consumption on blood lipids.

DATA SYNTHESIS

A systematic literature search of Embase, Web of Science, PubMed and Cochrane Controlled Trials Registry was conducted for studies that investigated the efficacy of probiotics on the plasma lipid profile of subjects. With the help of Review Manager 4.2, data from 13 trials, which included 485 participants with high, borderline high and normal cholesterol levels, were examined. The pooled mean net change in total cholesterol for those treated with probiotics compared to controls was -6.40 mg dl(-1) (95% confidence interval (CI), -9.93 to -2.87), mean net change in low-density lipoprotein (LDL) cholesterol was -4.90 mg dl(-1) (95% CI, -7.91 to -1.90), mean net change in high-density lipoprotein (HDL) cholesterol was -0.11 mg dl(-1) (95% CI, -1.90-1.69) and mean net change in triglycerides was -3.95 mg dl(-1) (95% CI, -10.32-2.42).

CONCLUSION

These results indicate that a diet rich in probiotics decreases total cholesterol and LDL cholesterol concentration in plasma for participants with high, borderline high and normal cholesterol levels.