Screening of taxol-producing endophytic fungi from Taxus chinensis var. mairei

A total of 38 endophytic fungus strains were isolated from Taxus chinensis var. mairei by aseptic technique. Genomic DNA was extracted from isolated endophytic fungi and subjected to polymerase chain reaction (PCR) analysis for the presence of Taxus taxadiene synthase (TS) gene, a rate-limiting enzyme gene in the taxol biosynthetic pathway. Twelve out of 38 isolated endophytic fungus strains showed PCR positive for the ts gene. Subsequently, taxol and its related compounds were extracted from culture filtrates and mycelia of the PCR positive strains, separated by column chromatography and analyzed by High Performance Liquid Chromatography and Mass Spectrum. The analysis result showed that 3 strains could produce taxol and its related compounds at the detectible level. This study indicates that molecular detection of the ts gene is an efficient method for primary screening of taxol or its related compounds-producing endophytic fungi which can improve prominently screening efficiency.

Diversity of the killer cell immunoglobulin-like receptor gene KIR2DS4 in the Chinese population

Human killer cell immunoglobulin-like receptors are a subfamily of the immunoglobulin superfamily, which map to the leukocyte receptor complex on chromosome 19. Here, we established polymerase chain reaction-sequence-based typing (PCR-SBT) procedures to identify alleles of the KIR2DS4 gene. The method was designed around the specific amplification of exons 4-5 of the KIR2DS4 gene. Genomic DNA from 105 healthy unrelated Chinese Han individuals were typed for the KIR2DS4 alleles. Each sample was assigned the KIR2DS4 alleles combination, consistent with the pairwise combinations of sequences of all the known KIR2DS4 alleles. We observed eleven different genotypes and four KIR2DS4 alleles in the population, with the KIR2DS4*00101 having the highest frequency, 0.576, and also confirmed the new KIR2DS4*007 allele. Our data demonstrated that the established PCR-SBT method for the KIR2DS4 allele typing was reliable.

Investigation of killer cell immunoglobulin-like receptors gene KIR3DL2 diversity and confirmation of KIR3DL2*015 in a Chinese population

Human killer cell immunoglobulin-like receptors (KIRs) are a subfamily of the immunoglobulin superfamily. Here, we established polymerase chain reaction-sequence-based typing (PCR-SBT) procedure to identify alleles of KIR3DL2 gene. The method was designed around the specific amplification of exon 3 to exon 4 and exon 8 to exon 9 of the KIR3DL2 gene. Genomic DNA from 104 healthy, unrelated Chinese Han individuals was typed for KIR3DL2 alleles. Each sample was assigned to the putative allele combination according to the sequences of all KIR3DL2 alleles. We observed 18 different genotypes and eight KIR3DL2 alleles in the population, with KIR3DL2*002 having the highest frequency of 0.558, and confirmed the new KIR3DL2*015 allele. Our data showed that the established PCR-SBT methods for KIR3DL2 allele typing were reliable, and Chinese Han population is distinct in KIR3DL2 allele frequencies.

Soluble factors from LPS- and PHA-activated PBMC induce MAPK, Stat1 and Stat3 phosphorylation in primary cultures of human term placental trophoblasts: implications for infection and prematurity

Infection of the maternal vaginal tract is one of the single most important antecedents of premature labor. We have hypothesized that the abundant local synthesis of pro-inflammatory cytokines that occurs during infection may disrupt the delicate "immunological cross-talk" that must occur between maternal and fetal tissues in order to carry pregnancy to term. These experiments were undertaken as part of a larger study directed at testing that hypothesis. We prepared primary cultures of human trophoblasts from term placentas. Cell cultures were stimulated with conditioned medium from resting, PHA or LPS-activated peripheral blood mononuclear cells (PBMC). Medium with LPS or PHA at the same concentration as that used to stimulate the PBMC was used as an additional control. Lysates were subjected to western blotting for activated forms of the mitogen-activated protein kinases (MAPK), Stat1, and Stat3. Western blotting showed phosphorylation of the Jun kinase (JNK), p38, and Erk1/Erk2 MAPK in trophoblasts incubated with conditioned medium from LPS or PHA-activated PBMC but not from medium from resting PBMC, or with PHA or LPS alone. Phosphorylation could be detected as early as 5 min and was still observable by 10 min, the latest time point tested. Similarly, Stat1 and Stat3 phosphorylation was observed within 10 min of exposure to conditioned medium and was still observable 10 min after exposure. Immunohistochemistry also demonstrated nuclear translocation of both Stat1 and Stat3 after stimulation of trophoblasts with medium from activated PBMC. These findings are compatible with the hypothesis that immunologic balance at the maternal-fetal interface is maintained by ongoing "cross-talk" between the fetus (and fetally-derived tissues) and the maternal immune system. Infection of the maternal vaginal tract may disrupt this delicate immunologic balance, initiating inflammatory events that ultimately result in preterm labor.

hCG Secretion in Human Choriocarcinoma JAR Cells is MAPK but not Stat3 Dependent: Contributions of TNFα and IL-1β to Inflammation-induced hCG Secretion

Inflammatory mediators play critical physiologic roles throughout the course of normal pregnancy. At the same time, uncontrolled inflammation appears to have an adverse affect on pregnancy outcome. Thus, a crucial task of reproductive immunology is to define the mechanisms through which inflammation is controlled at the maternal-fetal interface. We examined the signaling pathways activated in the human choriocarcinoma cell line, JAR, in response to an in vitro model of an inflammatory challenge. We incubated JAR cells with medium from peripheral blood mononuclear cells (PBMC) that had been activated with either LPS or PHA. Conditioned medium from each experimental model induced MAP kinase and Stat3 phosphorylation as well as human chorionic gonadotropin (hCG) secretion from JAR cells. hCG secretion could be blocked by pharmacologic inhibition of MAP kinase but not by inhibition of Stat3 using an siRNA approach. The MAPK activators IL-1beta and TNFalpha both induced hCG secretion from JAR cells, but not the Stat3 activators IFN-gamma and IL-6. Furthermore, hCG secretion induced by conditioned media could be blocked by IL-1 receptor antagonist. We conclude that inflammation at the maternal-fetal interface may involve complex webs of regulatory and counter-regulatory mechanisms that involve multiple cytokines and at least two major, independent cell-signaling systems.

Investigation of killer cell immunoglobulin-like receptor KIR2DL4 diversity by sequence-based typing in Chinese population

Human killer cell immunoglobulin-like receptors (KIRs) play an important role in controlling natural killer (NK) cell function. Here, polymerase chain reaction sequence-based typing (PCR-SBT) procedures identifying alleles of the KIR2DL4 gene have been established. The method was designed around the specific amplification of exon 3 to exon 5 and exon 7 to exon 9 of the KIR2DL4 gene and produce discrimination of KIR2DL4 alleles. Genomic DNAs from 83 healthy unrelated Chinese Han individuals were typed for KIR2DL4 alleles by this method. Each sample was assigned to the putative KIR2DL4 allele combination according to the nucleotide polymorphism profiles of all KIR2DL4 alleles. Twenty-one different genotypes and seven KIR2DL4 alleles were observed in the population, with KIR2DL4*00102 having the highest frequency, 0.5. Five individuals bear a recombinant allele KIR3DP*004 that associated with three putative KIR2DL4 alleles. Our data demonstrated that the established PCR-SBT method for KIR2DL4 allele typing was reliable, and Chinese Han population is distinct in KIR2DL4 allele frequencies in comparison to some other populations.

Distribution of killer cell immunoglobulin-like receptor genes in the Chinese Han population

Killer cell immunoglobulin-like receptors (KIRs) on natural killer cells recognize groups of HLA class I alleles. Seventeen KIR genes have been identified at present, and two kinds of KIR haplotypes (group A and B) have been described based on their gene contents. Immunogenetic analysis of different ethnic populations shows significant differences in terms of the distribution of group A and B haplotypes. Here, genomic DNA from 104 healthy unrelated Chinese Han individuals was typed for the presence or absence of KIR genes. All 17 KIR genes were observed in the population, and framework genes 3DL3, 3DP1, 2DL4, and 3DL2 were present in all individuals. Twenty-six different genotypes were found, four of which could not be assigned to haplotypes according to the model of Hsu et al. (J Immunol 2002: 169: 5118). Group A haplotypes outnumbered group B haplotypes in frequency by approximately 3:1, with individuals having two group A haplotypes accounting for 58.7%. Analysis indicated that some pairs of KIR genes showed remarkable linkage disequilibrium. Our data demonstrated that the Chinese Han population is distinct in KIR gene frequencies and putative KIR haplotypes in comparison to some other populations.

Genome-wide identification of NBS genes in japonica rice reveals significant expansion of divergent non-TIR NBS-LRR genes

A complete set of candidate disease resistance ( R) genes encoding nucleotide-binding sites (NBSs) was identified in the genome sequence of japonica rice ( Oryza sativaL. var. Nipponbare). These putative R genes were characterized with respect to structural diversity, phylogenetic relationships and chromosomal distribution, and compared with those in Arabidopsis thaliana. We found 535 NBS-coding sequences, including 480 non-TIR (Toll/IL-1 receptor) NBS-LRR (Leucine Rich Repeat) genes. TIR NBS-LRR genes, which are common in A. thaliana, have not been identified in the rice genome. The number of non-TIR NBS-LRR genes in rice is 8.7 times higher than that in A. thaliana, and they account for about 1% of all of predicted ORFs in the rice genome. Some 76% of the NBS genes were located in 44 gene clusters or in 57 tandem arrays, and 16 apparent gene duplications were detected in these regions. Phylogenetic analyses based both NBS and N-terminal regions classified the genes into about 200 groups, but no deep clades were detected, in contrast to the two distinct clusters found in A. thaliana. The structural and genetic diversity that exists among NBS-LRR proteins in rice is remarkable, and suggests that diversifying selection has played an important role in the evolution of R genes in this agronomically important species. (Supplemental material is available online at http://gattaca.nju.edu.cn.)

T cell activation by soluble C1q-bearing immune complexes: implications for the pathogenesis of rheumatoid arthritis

Both innate and adaptive immune systems are thought to participate in the pathogenesis of rheumatoid arthritis in adults and children. The experiments reported here were undertaken to examine how immune complexes, potent stimulators of inflammation, may regulate cells of the adaptive immune system. Human T cells were prepared from peripheral blood by negative selection and incubated with bovine serum albumin (BSA)-anti-BSA immune complexes that were formed in the presence or absence of human C1q. C1q-bearing immune complexes, but not unopsonized complexes, elicited both TNF-alpha and IFN-gamma secretion from human T cells. Secretion of both cytokines was time- and dose-dependent. Cross-linking C1q on the cell surface of T cells produced the same results. Cytokine secretion was not inhibited by blocking the C3b receptor (CR1, CD35) on T cells prior to incubation with immune complexes. Reverse transcriptase polymerase chain reaction (RT-PCR) of immune complex-stimulated cells revealed accumulation of both TNF-alpha and IFN-gamma mRNA within 2 h post-stimulation. IL-2 was not detected in cell culture supernatants, but IL-2 receptor alpha chain (CD25) was detected in low density on a small proportion of T cells activated by C1q-bearing immune complexes. Secretion of both cytokines was inhibited partially, but not completely, by IL-10. These experiments show that immune complexes, potent inflammatory mediators, may activate T cells through a novel mechanism. These findings have implications for chronic inflammatory diseases in humans.

Effect of rizatriptan and other triptans on the nausea symptom of migraine: a post hoc analysis

OBJECTIVE

To compare the effects of oral rizatriptan, sumatriptan, naratriptan, and zolmitriptan on the relief and emergence of nausea during a migraine attack.

METHODS

Data from five randomized, placebo-controlled, double-blind clinical trials in which oral rizatriptan 10 mg was directly compared with oral sumatriptan 100 mg (N = 772), 50 mg (N = 1168), 25 mg (N = 1180), naratriptan 2.5 mg (N = 406), or zolmitriptan 2.5 mg (N = 571) for the acute treatment of a migraine attack were retrospectively analyzed. Migraine was diagnosed according to International Headache Society criteria. Presence or absence of nausea was recorded at baseline and at 0.5, 1, 1.5, and 2 hours after dosing. The end points analyzed were relief of nausea in those who had it at baseline and emergence of nausea in those who were free of it at baseline. Treatments were compared using odds ratios estimated from logistic regression models at 2 hours, and averaged odds ratios for the first 2 hours posttreatment.

RESULTS

Approximately 60% of patients in each treatment group had nausea at baseline. In those patients with nausea at baseline, significantly more patients treated with rizatriptan 10 mg were free of nausea at 2 hours compared with sumatriptan 100 mg (66% versus 58%, P =.043), sumatriptan 50 mg (68% versus 57%, P =.010), sumatriptan 25 mg (68% versus 59%, P =.017), and naratriptan 2.5 mg (59% versus 45%, P =.014). Averaging over the four posttreatment time points in the first 2 hours, significantly more patients treated with rizatriptan 10 mg were free of nausea compared with sumatriptan 100 mg (P =.004), sumatriptan 50 mg (P =.001), and naratriptan 2.5 mg (P =.015). No significant differences in nausea relief were seen between rizatriptan 10 mg and zolmitriptan 2.5 mg, either at 2 hours (65% versus 61%, P =.210) or over the first 2 hours (P =.781). Rates of treatment-emergent nausea at 2 hours ranged from 11% to 18% with placebo, from 5% to 13% with rizatriptan 10 mg, and from 10% to 20% with other comparator triptans.

CONCLUSIONS

Oral rizatriptan 10 mg was more effective than oral sumatriptan and naratriptan at eliminating nausea within 2 hours in patients who had it at baseline. Rates of emergent nausea in patients who were free of it at baseline were low, and no consistent differences were observed between active treatments.

[The composition of PAHs in fly ash in Beijing]

The composition of polycyclic aromatic hydrocarbons (PAHs) in fly ash samples which were gathered from manufacturing district of Shijingshan district and residential quarters of Haidian district were analyzed using HPLC/MS technique. The differences of the contents of PAHs in fly ash samples from manufacturing district and residential quarters were compared. The changes of the contents of PAHs of different seasons were discussed. In this study 135 PAHs including 55 large PAHs whose molecular weights are greater than 300u were detected in fly ash sample from manufacturing district. HPLC/MS offset the deficiency of GC/MS which can not determine large PAHs directly and can reflect the distribution of PAHs in fly ash more roundly.

Cooperative regulation of Mcl-1 by Janus kinase/stat and phosphatidylinositol 3-kinase contribute to granulocyte-macrophage colony-stimulating factor-delayed apoptosis in human neutrophils

Polymorphonuclear neutrophils (PMN) are phagocytic cells constitutively programmed for apoptotic cell death. Exposure to GM-CSF delays apoptosis as measured by annexin-V staining and cell morphological change. We found that STAT5B, STAT1, and STAT3 DNA-binding activity was induced by GM-CSF. We also detected activation of the phosphatidylinositol 3-kinase (PI 3-kinase) pathway after GM-CSF treatment which was inhibited by treatment with the PI 3-kinase inhibitors, wortmannin and LY294002. We investigated whether STAT or PI 3-kinase activity was necessary for the pro-survival response of GM-CSF in PMN. Exposure of PMN to GM-CSF in the presence of either AG-490, antisense STAT3 oligonucleotides, or wortmannin resulted in a partial inhibition of GM-CSF-mediated pro-survival activity. GM-CSF induced a time-dependent increase in the mRNA and protein expression of the anti-apoptotic Bcl-2-family protein, Mcl-1. We examined the hypothesis that Janus kinase/STAT and PI 3-kinase regulation of Mcl-1 contributed to GM-CSF-delayed apoptosis. Using either AG-490 or wortmannin alone, we observed a dose-dependent inhibition of GM-CSF-induced Mcl-1 expression. Using suboptimal doses of AG-490 and wortmannin, we found that both drugs together had an additive effect on delayed apoptosis and Mcl-1 expression. These data suggest that cooperative regulation of Mcl-1 by the Janus kinase/STAT and PI 3-kinase pathways contribute to GM-CSF-delayed apoptosis.

[Study of susceptibility loci located within Xp11 in attention deficit hyperactivity disorder]

OBJECTIVE

To detect the genetic relationship between monoamine oxidase(MAO) A type gene and attention deficit hyperactivity disorder(ADHD) in Chinese.

METHODS

The haplotype-based haplotype relative risk(HHRR) and the transmission disequilibrium test(TDT) methods were used to analyze the genetic association and linkage in 60 ADHD children and their parents.

RESULTS

In this sample were found significant association (chi(2)=4.90, P<0.05) and linkage (chi(2)=4.84, P<0.05) between the MAOCA 114bp allele and DSM-III-R-diagnosed ADHD in trios composed of father, mother and affected offspring.

CONCLUSION

The above results suggested that ADHD was associated and in linkage with MAO A gene, and the susceptibility loci might reside in chromosome Xp11 for ADHD.

[Reversed trabeculectomy for treatment of glaucoma]

OBJECTIVE

To reduce the postoperative blocking of the filtration canal in routine trabeculectomy with modification.

METHODS

The modification of the procedure of routine trabeculectomy was that one end of the 4.0 mm x 1.5 mm deep layer scleral tissue including part of trabecular meshwork was not cut. Instead, the free end of the strip of deep scleral tissue was vertically rotated and sutured on the deep layer of the scleral bed posterior to it. The projection of the strip was utilized to prevent postoperative blocking of filtration canal.

RESULTS

The mean period of postoperative follow-up was 23.5 months (range, 12 -- 36 months). In the treatment group (38 eyes of 33 cases), the intraocular pressure (IOP) was lowered from preoperative (25.41 plus minus 2.41) mm Hg to postoperative (14.74 plus minus 0.90) mm Hg. The IOP was lowered from preoperative (24.96 plus minus 1.35) mm Hg to postoperative (19.40 plus minus 1.43) mm Hg in the control group (40 eyes of 33 cases). The success rates were 94.7% and 77.5% in the treatment and control group respectively.

CONCLUSIONS

The modified trabeculectomy is safe, easy to perform, and can effectively relieve the postoperative blocking of the filtration canal, control postoperative IOP and reduce postoperative recurrence.

Accumulation of abnormal amounts of glycosaminoglycans in murine mucopolysaccharidosis type VII neural progenitor cells does not alter the growth rate or efficiency of differentiation into neurons

Mucopolysaccharidosis type VII (MPS VII) results from deficiencies in the gene encoding the lysosomal enzyme beta-glucuronidase (GUSB). To study how the genetic and biochemical defects of MPS disease affect neural cell populations, neural progenitor cells (NPCs) were isolated from MPS VII mice and normal littermates. After growth in culture, approximately 90% of cells from both genotypes were nestin positive, a marker for NPCs, and lacked markers associated with lineage commitment. The mutant NPCs contained elevated levels of undegraded glycosaminoglycans (GAGs), the substrate for GUSB. Transduction with a retrovirus-vector expressing normal GUSB resulted in correction of the biochemical defects. Because of the demonstrated roles that GAGs and proteoglycans have in NPC biology and neural development, we tested whether the alterations in GAG metabolism affected MPS VII NPC properties regulated by GAG-containing molecules. MPS VII NPC cultures had growth rates in response to FGF-2 that were similar to normal cultures and the efficiency of differentiation into neurons was the same as with normal cells. Thus, even though isolated NPCs accumulate abnormally high levels of GAGs, these two key developmental properties were not altered when the cells were examined outside the milieu of the diseased brain.

Detection of glutamic acid decarboxylase-activated T cells with I-Ag7 tetramers

CD4(+) T cells selected by the type 1 diabetes associated class II MHC I-A(g7) molecules play a critical role in the disease process. Multivalent MHC/peptide tetramers have been used to directly detect antigen-specific T cells. Detection of autoantigen-activated CD4(+) T cells with tetramers should be very helpful in the study of the roles of these cells in diabetes. We report here the generation of tetramers of I-A(g7) covalently linked to two glutamic acid decarboxylase (GAD) peptides and the detection of GAD peptide-activated T cells from nonobese diabetic (NOD) mice. The I-A(g7) heterodimers can form stable complexes with a covalently bound GAD peptide and can stimulate antigen specific T cells. Furthermore, I-A(g7)/GAD peptide tetramer can detect most if not all of the antigen-specific CD4(+) T cells from immunized NOD mice. Antigen-specific T cells detected by the tetramers can up-regulate their CD4 expression on the cell surface after being restimulated with the GAD peptides in vitro. In contrast, the tetramers can detect a percentage of T cells in lymph nodes and spleens and T cells infiltrating islets from nonimmunized mice that is not significantly above the background. Therefore, T cells specific for the GAD peptides are present in NOD mice at a frequency too low to be detected, but immunization of NOD mice can facilitate their detection by tetramers.

Pivotal role of phosphoinositide-3 kinase in regulation of cytotoxicity in natural killer cells

The mitogen-activated protein kinase-extracellular signal-regulated kinase signaling element (MAPK-ERK) plays a critical role in natural killer (NK) cell lysis of tumor cells, but its upstream effectors were previously unknown. We show that inhibition of phosphoinositide-3 kinase (PI3K) in NK cells blocks p21-activated kinase 1 (PAK1), MAPK kinase (MEK) and ERK activation by target cell ligation, interferes with perforin and granzyme B movement toward target cells and suppresses NK cytotoxicity. Dominant-negative N17Rac1 and PAK1 mimic the suppressive effects of PI3K inhibitors, whereas constitutively active V12Rac1 has the opposite effect. V12Rac1 restores the activity of downstream effectors and lytic function in LY294002- or wortmannin-treated, but not PD98059-treated, NK cells. These results document a specific PI3K-->Rac1-->PAK1-->MEK-->ERK pathway in NK cells that effects lysis.

IL-2 induces the association of IL-2Rbeta, lyn, and MAP kinase ERK-1 in human neutrophils

IL-2, first identified as a T cell growth factor, has been proven to activate many cell types including polymorphonuclear neutrophils (PMN3). However, the mechanisms involved in PMN activation, especially the signaling pathways used by the IL-2R, are currently unknown. Here we demonstrate that IL-2 has the ability to induce protein tyrosine kinases in human PMN, and we provide the first evidence that lyn kinase is activated and physically associated with MAP kinase/ERK1. Co-immunoprecipitation experiments with anti-IL-2Rbeta and Western blotting with anti-p53/56lym revealed that lyn protein was present in IL-2R precipitates and that the association of lyn with IL-2Rbeta was markedly elevated by IL-2 stimulation. Furthermore the activity of lyn kinase, evaluated by an in vitro kinase assay with enolase as a substrate, increased following IL-2 stimulation. Another important finding was that, upon IL-2 activation, MAPK/ERK1 was also phosphorylated in PMN. A direct association between lyn and ERK1 was initially demonstrated by co-immunoprecipitation/Western blotting and then definitively proven by the use of a GST-ERK1 fusion protein. We showed that ERK1 binds lyn only in IL-2 stimulated PMN, but not in unstimulated PMN. These results suggest that IL-2 can promote the association of lyn protein tyrosine kinase with IL-2Rbeta as well as the direct binding of MAPK/ERK1 to lyn. The signaling pathway utilized by human PMN in response to IL-2 may thus involve the association of lyn with IL-2Rbeta and the activation process also triggers the recruitment and activation of a specific ERK.

[The identification and cloning of human ubiquitin binding enzyme cDNA]

OBJECTIVE

To identify and clone the gene encoding human ubiquitin binding enzyme and study its expression spectrum.

METHODS

According to the sequence of human EST, which is highly homologous to the mouse ubiquitin conjugating enzyme (E2), primers used for library screening were synthesized to screen the human fetal brain cDNA library. The gene was analyzed by making use of bioinformatics and its expression spectrum was studied by using multiple-tissue Northern blot.

RESULTS

Two cDNA clones encoding human ubiquitin conjugating enzyme were isolated and identified. Both containing the ubiquitin conjugating domain, they were 88% identical in amino acid sequences and found to be isoforms of each other with only an exon excised from the short sequence. They belonged to a highly conserved, and widely expressed E2 enzyme family. Northern blot showed that they were expressed exclusively in heart, placenta, and pancreas while no transcripts could be detected in brain, lung, liver, skeletal muscle, or kidney.

CONCLUSIONS

The gene encoding human ubiquitin binding enzyme is expressed under both temporal and spatial control. As a key enzyme in the degradation of proteins, ubiquitin conjugating enzymes play a central role in the expression regulation on the level of post-translation.

Auxin metabolism in the root apical meristem

Within the root meristem of flowering plants is a group of mitotically inactive cells designated the quiescent center (QC). Recent work links the quiescent state to high levels of the growth regulator auxin that accumulates in the QC via polar transport. This in turn results in elevated levels of the enzyme ascorbic acid oxidase (AAO), resulting in a reduction of ascorbic acid (AA) within the QC and mitotic quiescence. We present evidence for additional interactions between auxin, AAO, and AA, and report that, in vitro, AAO oxidatively decarboxylates auxin, suggesting a mechanism for regulating auxin levels within the QC. We also report that oxidative decarboxylation occurs at the root tip and that an intact root cap must be present for this metabolic event to occur. Finally, we consider how interaction between auxin and AAO may influence root development by regulating the formation of the QC.

The phosphoinositide 3-OH kinase/AKT2 pathway as a critical target for farnesyltransferase inhibitor-induced apoptosis

Farnesyltransferase inhibitors (FTIs) represent a novel class of anticancer drugs that exhibit a remarkable ability to inhibit malignant transformation without toxicity to normal cells. However, the mechanism by which FTIs inhibit tumor growth is not well understood. Here, we demonstrate that FTI-277 inhibits phosphatidylinositol 3-OH kinase (PI 3-kinase)/AKT2-mediated growth factor- and adhesion-dependent survival pathways and induces apoptosis in human cancer cells that overexpress AKT2. Furthermore, overexpression of AKT2, but not oncogenic H-Ras, sensitizes NIH 3T3 cells to FTI-277, and a high serum level prevents FTI-277-induced apoptosis in H-Ras- but not AKT2-transformed NIH 3T3 cells. A constitutively active form of AKT2 rescues human cancer cells from FTI-277-induced apoptosis. FTI-277 inhibits insulin-like growth factor 1-induced PI 3-kinase and AKT2 activation and subsequent phosphorylation of the proapoptotic protein BAD. Integrin-dependent activation of AKT2 is also blocked by FTI-277. Thus, a mechanism for FTI inhibition of human tumor growth is by inducing apoptosis through inhibition of PI 3-kinase/AKT2-mediated cell survival and adhesion pathway.

Studies of the DXS7 polymorphism at the MAO loci in unipolar depression

From the fact that DXS7 polymorphism is closely related to monoamine oxidase (MAO) genes and MAO inhibitors are widely used in the treatment of unipolar depression, it is of particular interest to study the relationship between the DXS7 polymorphism and unipolar depression. Thus, this study examined the possible association between DXS7 polymorphism and unipolar depression in 66 cases versus 85 controls from Shanghai. Polymerase chain reaction and amplification fragment length polymorphism techniques were used for genotyping of the DXS7 locus in this study. Four alleles at the DXS7 locus were detected with length generated by polymerase chain reaction amplification ranging from 157 to 167 bp. Comparison of allele frequency in the DXS7 locus showed no difference between unipolar depression cases and normal controls in the total population set. When subclassified by age, a significant difference of allele frequency distribution was observed between early onset (before age 40) and late onset (after age 40) patients. The frequency of the 157-bp allele was decreased, whereas the frequency of the 165 allele was increased in late onset patients (0.3810 for the 157-bp allele and 0.5238 for the 165-bp allele) compared with that of early onset patients (0.6304 for the 157-bp allele and 0. 3261 for the 165-bp allele). There was also a difference of allele frequency between patients and normal controls with age over 40 years. The frequency of 165-bp allele increased significantly in late onset patients (0.5238) compared with that of controls within the same age range (0.3454). Association studies suggested that in the population with age over 40 years, presence of the 165-bp allele of DXS7 locus was significantly associated with unipolar depression (relative risk = 2.08, P < 0.05), whereas in the total population set, this association did not exist. Am. J. Med. Genet. (Neuropsychiatr. Genet.) 88:598-600, 1999.

[Genetic association between mood disorder and monoamine oxidase gene]

OBJECTIVE

To ascertain whether the mood disorder (bipolar and unipolar) is genetically associated with genes polymorphisms of MAOA type and MAOB type in the Chinese.

METHODS

One hundred and thirty-two cases of Chinese with mood disorder were genotyped for the MAOA(CA)n, MAOB(GT)n and MAOB(TG)n locus using Amp-FLP.

RESULTS

Among 132 cases with mood disorder, 8 alleles (size: 112-126 bp) of MAOA(CA)n, 12 alleles (size: 168-198 bp) of MOAB(GT)n and 9 alleles (size: 195-213 bp) of MAOB(TG)n locus were observed. Comparison of the polymorphisms of all alleles in the three locus showed that no significant difference (P > 0.05) was seen in the frequency distribution between cases with mood disorder (bipolar and unipolar) and controls, but the frequency of 180 bp allele for MAOB(GT)n and 250 bp allele for MAOB(TG)n was significantly different (P < 0.05) between the two groups.

CONCLUSION

MAO gene (type A and B) is not associated with mood disorder in the Chinese.

Time-to-event analysis, or who gets better sooner? An emerging concept in headache study methodology

Survival analysis, or, more generally, time-to-event analysis, is of interest when the data represent the time to a defined event. While well established in oncology, it has not been widely applied to migraine research, possibly because the data are usually collected intermittently, rather than continuously, and because of the awkwardness of interpreting treatment effect in survival terms. However, it represents an interesting approach for the analysis of time-to-headache relief, which addresses the clinically relevant question of who gets better sooner. The analysis uses data from all time-points to define the likelihood of headache relief following treatment throughout the entire assessment period. These data can then be used to quantify and test the difference between two therapies.

Efficacy and safety of rizatriptan wafer for the acute treatment of migraine. Rizatriptan Wafer Protocol 049 Study Group

Rizatriptan is a potent, highly selective 5HT1B/1D agonist with rapid onset of action for acute treatment of migraine. Rizatriptan wafer is a novel, freeze-dried dosage formulation of rizatriptan which rapidly disintegrates on the tongue, is swallowed with saliva, and may be taken without liquids. The efficacy and tolerability of rizatriptan wafer were examined in a placebo-controlled, double-blind, outpatient study in 555 migraineurs. The primary efficacy endpoint was pain relief at 2 h. From 30 min onwards, significantly more patients experienced pain relief and became pain-free after rizatriptan 10-mg wafer compared to placebo. At 2 h, the percentage of patients with pain relief was significantly higher after rizatriptan 10-mg wafer (74%), 5-mg wafer (59%) compared with placebo (28%). Rizatriptan 10-mg wafer was superior to rizatriptan 5-mg wafer on pain relief at 1.5 and 2 h (p < 0.05). Significantly more patients were pain-free at 2 h after rizatriptan 10-mg wafer (42%), 5-mg wafer (35%) compared with placebo (10%). Both doses of rizatriptan wafer were well tolerated. Rizatriptan wafer is a convenient, highly effective new formulation for acute treatment of migraine.

[HRV analysis system based on Windows 95 and its preliminary application]

Objective. To provide a real useful application system for the HRV research. Method. The acquisition, detection and analysis system of HRV signal was set up based on Windows 95. The system analyzes the HRV signal with statistic method in time domain and power spectrum in frequency domain. And the power spectrum array was also introduced into the analysis. HRV signals of some healthy persons and some patients were detected and analyzed. Result. The HRV characteristic is much more obvious in the diabetics patients. Conclusion. The system is useful in HRV signal analysis and cardiovascular research.

Transcriptional control of the galanin gene. Tissue-specific expression and induction by NGF, protein kinase C, and estrogen

Galanin is a neuropeptide widely expressed in the central and peripheral nervous system where it acts as a neurotransmitter/neuromodulator and possibly an immunoregulator and growth factor. Galanin gene expression is highly regulated during development and by certain hormones and injury situations. We have examined transcriptional control mechanisms for this gene using chimeric bovine galanin/luciferase reporter genes. These were analyzed in cultured cells and in transgenic mice. The studies reveal that enhancer and silencer sequences are involved in conferring cell- and tissue-specific expression, and that specific elements close to the promoter are responsible for nerve growth factor and protein kinase C induction. So far, the studies have not revealed sequences on the bovine gene that mediate the action of estrogen.

Crossover comparison of rizatriptan 5 mg and 10 mg versus sumatriptan 25 mg and 50 mg in migraine. Rizatriptan Protocol 046 Study Group

Rizatriptan is a selective 5-HT1B/1D receptor agonist with rapid oral absorption and early onset of action in the acute treatment of migraine. This double-blind, placebo-controlled, crossover study compared rizatriptan 5 mg versus sumatriptan 25 mg, and rizatriptan 10 mg versus sumatriptan 50 mg. A total of 1329 patients were allocated to one of five groups for treatment of two attacks: rizatriptan 5 mg/sumatriptan 25 mg; sumatriptan 25 mg/rizatriptan 5 mg; rizatriptan 10 mg/sumatriptan 50 mg; sumatriptan 50 mg/rizatriptan 10 mg; placebo/placebo. For each attack, patients rated headache severity, presence of associated symptoms, and functional disability prior to dosing and at intervals through 4 hours thereafter. Patients also rated their satisfaction with medication. Rizatriptan 5 mg and 10 mg provided faster relief of headache pain and greater relief of migraine symptoms than the 25-mg and 50-mg doses of sumatriptan, respectively. The response to rizatriptan was better than sumatriptan on additional measures including functional disability and satisfaction with medication. All active treatments were highly effective compared to placebo and acted as early as 30 minutes after dosing. All active treatments were well-tolerated and showed comparable safety profiles.

Characterization of phorbolester-inducible human neuronal factors involved in trans-activation of the galanin gene

The expression of the neuropeptide galanin (GAL) is elevated in vivo upon nerve stimulation, injury, and in vitro by phorbol 12-myristate-13-acetate (PMA), suggesting that a signal pathway involving protein kinase C activation may be involved in GAL-gene activation. When plasmids containing a different length of the bovine GAL-promoter fused to luciferase were transfected into the human neuroblastoma cell line (SK-N-SH subclone SH-SY5Y), a PMA-responsive element was identified in the promoter-region -68 to -46 base pairs (bp). Co-transfection experiments with plasmids expressing cJun and cFos revealed that they could act alone, as well as synergistically with PMA to induce luciferase activity. Electrical mobility shift assays revealed that a cAMP response element (CRE)-like sequence (TGACGCGG; -59 to -52 bp) bound PMA-inducible nuclear proteins present in SH-SY5Y cells. These proteins appear to bind mainly as CRE-binding protein/activating-transcription-factor (CREB/ATF) and Jun/ATF heterodimers. In addition, an apparent PMA-inducible protein(s) not recognized by CREB/ATF and Jun antibodies bound to the CRE-like containing probe.

[Effect of cyclic loads on revascularization in healing of bone defect]

In order to study the biomechanical effect of cyclic loads on revascularization in bone healing, 20 rabbits were chosen for following experiments. Two 2 mm in diameter holes were made at the middle segment of both right and left tibia. A 2 mm in diameter nail was put in 15 mm proximal to the upper hole, and another was put in 15 mm distal to the lower hole. The wound was covered by direct suture with the ends of the nails kept 15 mm out of skin. The medial ends of the two nails were fixed by an iron plate, while the lateral ends were left for cyclic loads. Three Hz cyclic loads, which was near to the cyclic forces when a rabbit runs, was added to the left tibia for experiment, and no loads was add to the right tibia for control. A group of five rabbits were sacrificed respectively in 5, 10, 20 and 30 days postoperatively. The solution of 2% India ink and gelatin was irrigated from aorta to the bone defects. Then the tibia was removed for histologic study. The changes of cells and microvessel were observed. It was shown that the revascularization in experiment group was about 7 days earlier than that of control. The effect was at its peak from 10 to 30 days. It was concluded that cyclic loads could promote revascularization in the healing process of bone defect.

[A multiexponential model in cavity ring-down absorption spectroscopy]

A multiexponential model of cavity ring-down absorption spectroscopy is established for taking into account the laser linewidth effects. It is demonstrated that by fitting the logarithmic ring-down function to a truncated polynomial, absorption coefficent can be extracted from coefficients of the first as well as higher order terms of the fitted polynomial. The new fit model results in higher accuracy and broader dynamic range than the previous single exponential model.

Rizatriptan (MAXALT) for the acute treatment of migraine and migraine recurrence. A placebo-controlled, outpatient study. Rizatriptan 022 Study Group

Rizatriptan is a novel 5-HT1B/1D agonist which is rapidly absorbed after oral administration. The efficacy and tolerability of oral rizatriptan (5 mg and 10 mg) were examined in this multicenter, double-blind, outpatient study of 1473 migraineurs which featured randomized, placebo-controlled treatment of migraine recurrences. On experiencing moderate or severe migraine headaches, patients rated headache severity prior to dosing and at 30-minute intervals for 2 hours after dosing. Onset of effect was seen as early as 30 minutes after dosing with rizatriptan 10 mg. At 2 hours postdose, the percentage of patients with pain relief was significantly higher after rizatriptan 5 mg (62%) or 10 mg (71%) compared with placebo (35%). Complete relief was also significantly higher after rizatriptan 5 mg (33%) and 10 mg (42%) compared with placebo (10%). In patients experiencing headache recurrence after initial benefit, further relief was obtained in 71% with rizatriptan 5 mg (placebo 54%) and in 82% with rizatriptan 10 mg (placebo 44%). Complete relief of recurrent headache was obtained in 36% with rizatriptan 5 mg, 49% with rizatriptan 10 mg, and 15% with placebo (P < 0.05). The most common drug-related adverse experiences were dizziness, somnolence, asthenia/fatigue, and nausea (the incidences of which were low and dose related). There was no increase in the incidence of adverse experiences after use of up to three doses of rizatriptan within 24 hours. We conclude that both doses of rizatriptan are effective and well tolerated in the acute treatment of migraine and migraine recurrence, with the 10-mg dose preferred as it is more effective with a faster onset of action.

Fibronectin type III repeats mediate RGD-independent adhesion and signaling through activated beta1 integrins

Many cell-surface and extracellular matrix proteins contain multiple modular domains known as fibronectin type III (FNIII) repeats. Cells adhere to the extracellular matrix proteins fibronectin and tenascin in part by the interaction of certain integrins with the Arg-Gly-Asp (RGD) sequence, displayed on specific FNIII repeats. We have found that, after experimental activation of beta1 integrins, a number of cell types adhere and spread on FNIII repeats lacking RGD, derived from extracellular matrix proteins and cytokine receptors. Interaction between individual FNIII domains and beta1 integrins mediates focal adhesion kinase phosphorylation and subsequent stress fiber and focal contact formation. These data suggest that many FNIII-containing proteins may bind and signal through activated beta1 integrins, dramatically expanding the potential for integrin-dependent intercellular and cell-matrix communication.

[Preliminary studies on proliferation of hemorrhagic fever with renal syndrome virus in Leptotrombidium (L.) Scutellare]

In order to observe further the proliferation and kinetic changes of hemorrhagic fever with renal syndrome virus (HFRSV) in Leptotrombidium (L.) Scutellare infected with HFRSV, the raised Leptotrombidium (L.) Scutellare which were at larve stage or at nymph stage were grinded and sterilized by filtration at interval of 20 days, each batch of the filtrate was inoculated separately to Vero-E6 cells and the titre (TCID50/ml) of HFRSV was measured. The results confirmed: HFRSV were isolated from each batch of larve besides the batch at the 60th days, and the titre of HFRSV was -10(-1)-10(-4); HFRSV were also isolated from two batches of nymph. The isolated HFRSV were amplified by PCR technique and the HFRSV RNA were positive. The above results give rise to evidence that Leptotrombidium (L.) Scutellare might be the transmission vector of HFRSV.

[Preparation and clinical application of blocking glue for cancerous serosa]

The blocking glue of cancerous serosa (F-TH glue) is unharmful to human body. It has characteristics of shorter solidification time to become membrane, good elasticity and close adherence to tissue, mainly used for covering cancerous serosa in operation to prevent dropping of cancer cells. In this group, F-TH glue was used in 200 cases of gastrointestinal cancer, in which 75 had positive results of imprinting slice of cancerous serosa, and all became negative. It was confirmed that the glue adhered to cancerous serosa firmly and formed intact protective membrane. No rhagades and dropping of glue were seem by naked eye magnifying glass and electron microscope. The membrane of glue forbid cancer cells not penetrated. It was an excellent glue to block the cancerous serosa.

Rizatriptan vs sumatriptan in the acute treatment of migraine. A placebo-controlled, dose-ranging study. Dutch/US Rizatriptan Study Group

BACKGROUND

Rizatriptan (MK-462) is a new 5-hydroxytryptamine1D (serotonin1D; 5-HT1D) receptor agonist for the acute treatment of migraine that has improved pharmacokinetic properties compared with sumatriptan succinate.

OBJECTIVE

To assess the efficacy and tolerability of 10-, 20-, and 40-mg doses of oral rizatriptan vs a 100-mg dose of oral sumatriptan succinate and placebo for the acute treatment of migraine.

DESIGN

Randomized, double-blind, parallel-group, placebo-controlled, outpatient trial.

SETTING

Ten US and 4 Dutch investigator centers.

PATIENTS

Patients who had migraine with or without aura (N = 449).

MAIN OUTCOME MEASURE

The proportion of patients whose conditions improved from severe or moderate headache immediately before dosing to mild or no headache at 2 hours after drug administration (ie, headache relief).

RESULTS

The proportion of patients with headache relief was 18% for placebo; 46% for sumatriptan; and 52% for 10-mg, 56% for 20-mg, and 67% for 40-mg rizatriptan. All differences with placebo were statistically significant (P < .001), and 40-mg rizatriptan was superior to sumatriptan (P = .01). The proportion of patients who became free of pain at 2 hours was 3% for the placebo-treated group; 22% for the sumatriptan-treated group; and 26%, 35%, and 47% for the group of patients who took the 10-, 20-, and 40-mg doses of rizatriptan, respectively (all differences with placebo, P < .005; 40-mg rizatripan vs sumatriptan, P = .001). The recurrence of headache within 24 hours was found to be equal across all treatment groups-approximately 40%. Adverse events (most commonly short-lasting mild or moderate dizziness and drowsiness) occurred more frequently after a 40-mg dose of rizatriptan was given than after the other treatments.

CONCLUSIONS

The antimigraine effect of 10- and 20-mg rizatriptan was superior to placebo, and comparable with that of 100-mg sumatriptan succinate; the efficacy of 40-mg rizatriptan was superior to that of both placebo and 100-mg sumatriptan succinate, although it was associated with a high frequency of adverse events.

The role of Leptotrombidium scutellare in the transmission of human diseases

OBJECTIVE

To investigate the role of Leptotrombidium (L.) scutellare in the transmission of hemorrhagic fever with renal syndrome (HFRS) and tsutsugamushi disease of autumn-type.

MATERIALS AND METHODS

Four criteria were used to ascertain this mite as transmitting vector of disease: (1) epidemiological evidence; (2) natural infection of pathogen; (3) ability to transmit pathogen via biting; (4) ability to transfer pathogen via transovarian route.

RESULTS

The results indicated that L. scutellare was the dominant species of chigger mite on rats. Its seasonal distribution was correlated with the incidence of these two diseases. This mite could be naturally infected by HFRS virus (HFRSV) and Rickettsia tsutsugamushi (Rt) and the mite could transmit HFRSV and Rt to vertebrates by biting and to its offspring via transovarian transmission.

CONCLUSIONS

These results have proved that L. scutellare can be a transmitting vector of HFRS and tsutsugamushi disease of autumn-type.

Microsurgical replantation of the avulsed scalp: report of 20 cases

Our 4-year experience with 20 patients who had suffered avulsion of 75 percent or more of the scalp is reviewed. All patients underwent replantation using microsurgical technique with 100 percent survival in 16, partial survival in 3, and failure in only 1 case. The emergency management and indications for replantation are demonstrated. The roles of sufficient preoperative preparation, generous debridement of damaged vessels, interpositional vein grafts, and the shortening of operative time in contributing to this success are emphasized. We developed a new surgical procedure called simultaneous vein grafts on donor and recipient sites in an effort to use less time in the anastomosis of interpositional vein grafts. Furthermore, we anastomosed the extra artery of the scalp to the vein on the recipient head when no suitable vein could be found. Intraoperative repair of the scalp sensory nerve and no postoperative use of any vasodilator or anticoagulant are discussed.

Effect of hypoxia and reoxygenation on regional activity of nitric oxide synthase in brain of newborn piglets

The activity of nitric oxide synthase (NOS) was measured in homogenates from cortex, striatum, hippocampus, cerebellum, pons, thalamus and midbrain of the brain of newborn piglets and the effects of hypoxia and posthypoxic period on this activity was evaluated. The control activities were 19.7, 31.5, 26.8, 16.7, 33.6, 19.3 and 39.4 pmol/mg protein per min, respectively. A 1 h period of hypoxia (an FiO2 of 7%) resulted in statistically significant decreases in the activity of NOS in every region of the brain except for the cortex, where the activity was not significantly altered compared to control. By 2 h of reoxygenation following such a hypoxic episode, the NOS activities increased to above control levels in all regions of the brain, but this increase was statistically significant compared to control only in thalamus. Since hypoxia induced the greatest decrease in NOS activity in the cerebellum, the kinetic constants of the enzyme were measured in homogenates from this region of brain. The decreased activity following the hypoxic episode was associated with an approximately four-fold increase in the apparent affinity (KM) for arginine with no significant change in the maximal rate of reaction (Vmax). The decrease in NOS activity subsequent to a hypoxic episode may contribute to the disturbances in cellular metabolism in the immature brain induced by episodes of hypoxia-reoxygenation.

[Effect of antisense c-erbB2 on biologic behaviour and chemotherapeutic drug sensitivity in human ovarian cancer cells]

OBJECTIVE

To explore the effects of antisense erbB2 on the biological behaviours and on chemotherapeutic drug sensitivity in human ovarian cancer cells.

METHODS

A recombinant retroviral expression vector: pDOR-erbB-neo was constructed which contain the neomycin resistant gene and the erbB2 cDNA 3.8kb antisense fragment. pDOR-erbB-neo was introduced into human ovarian cancer cell line SKOV3 by lipofectin. The cells were selected with geneticin (G418). The cells transfected with pDOR-erbB-neo were named SKOV3-A2.

RESULTS

Southern blot analysis confirmed the presence of the antisense erbB2 in transfected cells. Transfected cells showed no obvious changes in morphology. Compared with parental cells and with pDOR-neo transfected cells used as controls, the growth and DNA synthesis of antisense transfected cells, SKOV3-A2, were inhibited. Transfection with pDOR-erbB-neo rendered the cells significantly, more sensitive to chemotherapeutic drugs (5-fluorouracil, cisplatinum) than the parental cells.

CONCLUSIONS

The effectiveness and the potentiality of antisense erbB2 in ovarian cancer gene therapy is demonstrated. c-erbB2 oncogene may be related to drug resistance in ovarian cancer cell.

1,25-Dihydroxyvitamin D3 stimulates the phosphorylation of two acidic membrane proteins of 42,000 and 48,000 daltons in rat colonocytes: an effect modulated by vitamin D status

Our laboratory has recently demonstrated that 1,25-dihydroxyvitamin D3(1,25(OH)2D3) rapidly stimulated membrane polyphosphoinositide breakdown and increased intracellular calcium, as well as activated protein kinase C (PKC) in vitamin D-sufficient rat colonocytes. These effects of 1,25(OH)2D3 were, however, lost in vitamin D-insufficient rats and restored by the in vivo repletion of 1,25(OH)2D3. In the present studies we have examined the ability of 1,25(OH)2D3 to stimulate the phosphorylation of colonic membrane proteins in intact D-sufficient cells. In addition, we investigated the effects of vitamin D status on the phosphorylation of these membrane proteins in broken cell preparations. These studies demonstrated that 1,25(OH)2D3 increased the phosphorylation of at least two colonic membrane proteins with apparent molecular weights of 42,000 (pp42) and 48,000 (pp48) in intact cells of vitamin D-sufficient rats. Moreover, in vitamin D-sufficient rats, treatment of colonocytes with 1,25(OH)2D3 or 12-O-tetradecanoyl phorbol 13-acetate (TPA), a known activator of PKC, significantly increased the phosphorylation of pp42 and pp48 in broken cell preparations. The kinetics of these phosphorylations in response to 1,25(OH)2D3 were both rapid and transient. In addition, PKC19-36, a specific PKC inhibitor, decreased the phosphorylation of pp42 and pp48, whereas okadaic acid (OA), a type 1 and 2A protein phosphatase inhibitor, further augmented their phosphorylation in response to 1,25(OH)2D3. The isoelectric points of pp42 and pp48 were 5.79 and 5.97, respectively, and both were predominantly phosphorylated on threonine residues. In contrast to our findings in colonocytes from vitamin D-sufficient animals, basal phosphorylation of pp42 and pp48 were increased in membranes prepared from vitamin D-insufficient rats. Moreover, these phosphorylations failed to change in response to 1,25(OH)2D3-treatment of colonocytes from vitamin D-insufficient rats. The basal phosphorylation of each of these proteins was restored to control levels, as was their ability to respond to the direct addition of 1,25(OH)2D3 following the in vivo repletion of vitamin D-insufficient rats with this secosteroid. In summary, we have identified two acidic membrane proteins from rat colonocytes that are phosphorylated in both intact and broken cell preparations in response to 1,25(OH)2D3 treatment, an event modulated by vitamin D status and mediated, at least in part, by PKC.

Comparison of dibenzodioxin levels in blood and milk in agricultural workers and others following pentachlorophenol exposure in China

Substantial amounts of sodium pentachlorophenol (Na-PCP) salts have been sprayed in certain areas in central China since the 1960s for control of snail-borne schistosomiasis. A sample of Na-PCP used in the area of concern was analyzed and showed 2,3,7,8-substituted dibenzodioxin (PCDD) and dibenzofuran (PCDF) congeners as well as some non-2,3,7,8-substituted congeners. Dibenzodioxin analysis of two pooled blood samples from 100 persons living in sprayed areas and a pooled sample from 26 individuals who had direct contact with the Na-PCP showed elevations of PCDD/F congeners found in the Na-PCP. Total PCDD/Fs ranged from 631 to 1252 parts per trillion (ppt) lipid in the blood of those exposed to Na-PCP, while two general population age-matched pooled blood samples from 50 persons each had total PCDD/Fs of 147 and 178 ppt. Toxic equivalents calculated with International Toxic Equivalency Factors (I-TEqs) ranged from 9 to 16.3 ppt in the blood samples from exposed persons while the general population blood I-TEqs were 4.8 and 6.4 ppt. A pooled breast milk sample from 50 women living in the sprayed areas was compared with a pooled sample from 50 women living in unsprayed areas. Total PCDD/Fs was low in both exposed and general population samples (134 and 42 ppt lipid, respectively), however, the women living in sprayed areas had considerably higher PCDDs, 129 ppt versus 34 ppt. The mothers exposed to Na-PCP had a I-TEq of 5.4, which was about double that of the mothers from the general population, 2.6 ppt, lipid. Although human PCDD and PCDF tissue levels in China are low compared with those in more industrialized countries, the higher levels in exposed persons are cause for concern.