Species-specific identification of human hookworms by PCR of the mitochondrial cytochrome oxidase I gene

Significant differences in the life histories of the human hookworms Ancylostoma duodenale and Necator americanus necessitate their differentiation for epidemiological studies and the design of control programs. Current methods of identification require time-consuming, labor-intensive techniques. A polymerase chain reaction (PCR)-based method that enables rapid species identification is described. The mitochondrial cytochrome oxidase I genes of both species were sequenced, and species-specific primer sets were designed. The primers were used in PCR to amplify 585-bp fragments of the cytochrome oxidase gene from individual hookworm eggs, larvae, and adults. The technique was also able to identify mixed infections containing equal amounts of eggs from each species. The technique is rapid, technically simple, and sensitive and will permit the accurate identification of human hookworms in epidemiological field studies.

C1q-bearing immune complexes induce IL-8 secretion in human umbilical vein endothelial cells (HUVEC) through protein tyrosine kinase- and mitogen-activated protein kinase-dependent mechanisms: evidence that the 126 kD phagocytic C1q receptor mediates immune complex activation of HUVEC

Endothelial cells play a pivotal role in the initiation and perpetuation of inflammation. C1q, the first component of the classical pathway of complement, is a potent stimulus leading to endothelial cell activation and cytokine production. The specific cellular mechanisms through which endothelial cells are stimulated by C1q are not known. We stimulated human umbilical vein endothelial cells (HUVEC) with either monomeric C1q or C1q-bearing immune complexes (C1q-IC) in the presence or absence of inhibitors of protein tyrosine kinases (PTK) or mitogen-activated protein kinases (MAPK). C1q-IC, but not monomeric C1q, induced IL-8 production in dose- and time-dependent fashion. R3, a cross-linking monoclonal IgM antibody against the 126 kD phagocytic C1q receptor (C1qR), also stimulated IL-8 production. IL-8 mRNA accumulation was detected by Northern blot analysis within 2 h of stimulation by the immune complexes and was enhanced by the addition of cycloheximide. Secretion of IL-8 by C1q-IC stimulated HUVEC was completely blocked by the PTK inhibitor, genistein or the MAPK inhibitor, UO126. These experiments demonstrate that C1q-IC-induced production of IL-8 in HUVEC is dependent upon the activation of PTK and MAPK. These findings also support a role for the phagocytic C1qR as an important activator of HUVEC by immune complexes.

Tegumental alterations in juvenile Schistosoma haematobium harboured in hamsters following artemether treatment

We report the findings of a detailed temporal study on tegumental alterations in juvenile Schistosoma haematobium, induced by artemether, using scanning electron microscopy. Hamsters infected with S. haematobium cercariae for 28 days were treated intragastrically with a single dose of 300 mg/kg artemether. Groups of two hamsters were killed 24 h, 72 h and 7 days after treatment, and schistosomula were recovered from livers by perfusion and subsequent systematic examination of the tissue, before routinely processing for scanning electron microscopic examination. Most schistosomula collected 24 h after artemether administration showed severe tegumental damage, usually including swelling, fusion, vesiculation, peeling and collapse of enlarged sensory structures. After 72 h, tegumental damage had increased and schistosomula generally showed contraction with extensive swelling, erosion and peeling of the tegument. Seven days post-treatment, severe tegumental damage was only seen in a single male specimen with swelling of the worm body and destruction of the oral sucker. The other schistosomula showed only light to moderate damage, suggesting that schistosomula surviving the treatment began to recover. Our findings of tegumental damage following artemether treatment correlate with the efficacy of this novel antischistosomal drug in killing the juvenile stages of S. haematobium and complement recent findings with S. japonicum and S. mansoni.

Effect of combined treatment with praziquantel and artemether on Schistosoma japonicum and Schistosoma mansoni in experimentally infected animals

Praziquantel and artemether are safe and efficacious antischistosomal drugs that act against different developmental stages of the parasite: praziquantel against adult worms and artemether against schistosomula. A combined treatment has been suggested as a strategy for transmission control. Recent laboratory experiments with rabbits with a mixed infection of Schistosoma japonicum parasites of different ages confirmed the effectiveness of a combination therapy. In the present work, we assessed the effect of a combined treatment on adult worms of S. japonicum and found significantly higher worm reduction rates than with a single dose of praziquantel. In a next step, we extended the study of the combined treatment to Schistosoma mansoni. A combined treatment with 75 mg/kg praziquantel and 150 mg/kg artemether was administered to hamsters infected with juvenile and adult S. mansoni. The two drugs, administered simultaneously or spaced by 6 h, 1, 3 or 7 days, resulted in significantly higher worm reduction rates than a single treatment with praziquantel. A combination therapy with increased doses of 100 mg/kg praziquantel and 300 mg/kg artemether showed very high worm reduction rates of 90% and above, however, some hamsters died in five different combined treatment experiments, suggesting that these drug concentrations were too high. We conclude that a combined treatment with praziquantel and artemether at the lower doses is safe and more effective than praziquantel alone, which forms a foundation for designing respective clinical trials in humans.

[Bioactivity and test grafting of acellular dermal matrix containing fibroblasts]

OBJECTIVE

To investigate the bioactivity of acellular dermal matrix with fibroblasts and its role as dermal skeleton.

METHODS

Human fibroblasts (HFs) were planted onto the surface of acellular dermal matrix (ADM) to form living dermal substitute. The IL -- 6, IL -- 8 and TGF contents in the supernatant of the culture of HF -- ADM were determined with ELISA method, and the secretion of hyaluronic acid and laminin from extracellular matrix was measured with RIA method. The speed of vascularization and the wound contracture rate were observed after the dermal substitute was grafted on the full skin loss wound of Balb/c-nu mice (nude mice).

RESULTS

HFs grew very well after being planted onto ADM so as to form a single layer of cellular membrane. Many kinds of cytokines and extra cellular matrix components were secreted. Compared with simple acellular dermal grafting, the vascularization was accelerated, and the wound contracture rate decreased, after the living dermal substitute being grafted on the wound.

CONCLUSION

The ADM seeded with HFs exhibited excellent bioactivity and might be an optimal dermal substitute.

Uremic levels of BUN do not cause nitric oxide deficiency in rats with normal renal function

In vitro, 7 days of high blood urea nitrogen (BUN) inhibits endothelial L-arginine transport and nitric oxide synthase (NOS) activity. The present study investigates whether 7 days of high BUN in vivo influences renal hemodynamics, blood pressure (BP), and/or the nitric oxide (NO) system. Normal rats were fed low-nitrate food containing 30% urea for 7 days, which increased BUN (15 +/- 1 to 69 +/- 4 mg/100 ml, P < 0.001). High BUN did not reduce 24-hour urinary nitrite/nitrate excretion (a measure of total NO production). Baseline BP and renal hemodynamics were unaffected by high BUN as were the pressor and renal vasoconstrictor responses to acute NOS inhibition with N(G)-nitro-L-arginine-methyl ester. In addition, high BUN had no impact on renal cortical L-arginine concentration, density of either endothelial NOS or neuronal NOS protein, or renal cortical NOS activity. NOS activity in the brain cerebellum was also unaffected. In conclusion, high BUN did not lead to vasoconstriction or NO deficiency in rats with normal renal function. Further studies are needed to evaluate the effect of high BUN on the NO system in rats with progressive renal functional insufficiency.

[Postlaryngectomy peristomal recurrence]

OBJECTIVE

To study the etiopathology, diagnosis and management of peristomal recurrence after laryngectomy, and the prevention of peristomal recurrence.

METHODS

Retrospective analysis of clinical management and outcomes of 16 cases of peristomal recurrence.

RESULTS

The subglottic extension of laryngeal cancer and peritracheal metastasis may result in peristomal recurrence. The stomal resection with mediastinal dissections and the use of the pectoralis major myocutaneous flap were done. The survival period of 11 cases surgically treated was longer than that of 5 cases irradiated or untreated.

CONCLUSION

Surgical management would improve the survival, but overall prognosis is dismal and attention should be focused on prevention. It is evident that early diagnosis of stomal recurrences will yield good results.

A new locus for hereditary gingival fibromatosis (GINGF2) maps to 5q13-q22

Gingival fibromatosis (GINGF) is an oral disorder characterized by enlargement of the gingiva. It occurs either as the sole phenotype or combined with other symptoms. Thus far, one GINGF locus has been mapped on chromosome 2, at 2p21, and a second possible locus has been mapped to 2p13. However, the genes responsible for this disorder have not been elucidated. We identified a four-generation Chinese GINGF family in which the disease manifests within 1 year after birth. After exclusion of the two known GINGF loci in this family, we performed a genome-wide search to map the chromosome location of the responsible gene. We identified a new locus, GINGF2, on chromosome 5q13-q22 with a maximum two-point lod score of 4.31 at D5S1721 (theta = 0.00). Haplotype analysis placed the critical region in the interval defined by D5S1491 and D5S1453. Within this region, calcium/calmodulin-dependent protein kinase IV (CAMK4) is a strong candidate.

Uremic levels of urea inhibit L-arginine transport in cultured endothelial cells

Hypertension in end-stage renal disease (ESRD) may involve lack of endothelial nitric oxide (NO), as suggested by reduced total NO synthase (NOS) in dialysis patients. One reason might be due to substrate deficiency. To test the hypothesis that uremia is a state of intracellular L-arginine deficiency, uremic plasma was obtained from dialysis patients, and its effect was tested on arginine transport in cultured vascular endothelial cells. L-arginine transport (P < 0.01) was reduced in human dermal microvascular endothelial cells (HDMEC) incubated for 6 h with 20% uremic plasma from peritoneal dialysis and hemodialysis patients obtained immediately predialysis. Similar transport inhibition was seen with ESRD plasma in human glomerular capillary and bovine aortic endothelial cells. Hemodialysis partially reversed inhibition of L-arginine transport. HDMECs incubated for 6 h with synthetic media containing high (uremic) urea concentrations showed inhibition of L-arginine transport, but this was not competitive because acute exposure to urea had no impact on L-arginine transport. Over a 6-h period, urea-induced inhibition of L-arginine transport was not sufficient to inhibit NOS activity, but after 7 days NOS activity was reduced. These cellular findings suggest that substrate delivery may be lowered, thus reducing endothelial NOS activity and contributing to hypertension in ESRD patients.

[Study on the tissue culture and plant regeneration of Pogostemon cablin]

Root tips, leaf segments, stem segments with node and stem segments of Pogostemon cablin (Blanco) Benth. were cultured in vitro. The results indicated that leaf segments and stem segments with node were suitable for callus formation, the frequency of callus induction were over 87.0%. A optimal medium for callus induction was MT + BA 0.5 mg/L + NAA 0.2 mg/L. MT basal medium with BA 0.5-1.0 mg/L were effective to induce differentiation of callus. And at the MT basal medium, the regenerative shoots from Pogostemon cablin could form roots.

Histopathological changes in juvenile Schistosoma haematobium harboured in hamsters treated with artemether

Histopathological changes in juvenile Schistosoma haematobium, caused by artemether administered to the infected hamsters, were studied. Hamsters were infected with S. haematobium cercariae, and after 28 days, a single dose of artemether (300 mg/kg) was administered intragastrically. After 24 h, 72 h and 7 days, groups of two hamsters were sacrificed, and livers were removed, fixed and processed routinely, and examined by light microscopy. After 24 h, 93% of the schistosomulae examined showed degeneration, which included swelling of the tegument, adherence of inflammatory cells to the damaged tegument, collapsed and damaged intestine, and infiltration of inflammatory cells, predominantly lymphocytes. After 72 h, the intensity of damage increased, including severe swelling of the tegument, loss of definition in the internal structures, collapse of intestine accompanied by release of pigment particles to the parenchymal tissues, and emergence of dead schistosomulae. Seven days after treatment, the number of dead schistosomulae increased, and most of them developed to an early- or late stage of dead worm granuloma. Meanwhile, 12% of the schistosomulae showed a normal appearance, which suggested that those schistosomulae that had survived the treatment were recovered to normal. The results demonstrated that artemether effectively acts against the juvenile stages of S. haematobium and confirms earlier results with S. japonicum and S. mansoni.

Circulating endothelial nitric oxide synthase inhibitory factor in some patients with chronic renal disease

BACKGROUND

Chronic renal disease (CRD) is associated with hypertension and reduced synthesis of nitric oxide (NO). Here, we investigated whether there is a circulating endothelial NO synthase (eNOS) inhibitory factor(s) in some patients with CRD that might directly influence endothelial NOS.

METHODS

Human dermal microvascular endothelial cells (HDMECs) were incubated for six hours with 20% plasma from subjects with normal renal function (PCr = 0.8 +/- 0.2 mg%), and patients with moderate renal insufficiency of various causes (PCr = 4.0 +/- 1.5 mg%) and impact on NOS activity, transport of L-arginine, and abundance of eNOS protein were measured. Plasma concentrations of asymmetric and symmetric dimethyl L-arginine (ADMA and SDMA) were also measured.

RESULTS

There was no effect of any human plasma on L-arginine transport. The NOS activity was variable in CRD patients and fell into two subgroups: CRD I, individual values similar to control, and CRD II, individual values lower than control mean. The effect of CRD plasma on NOS activity in cultured cells was not related to the primary disease, but was predicted by plasma ADMA levels since plasma ADMA was elevated in CRD II versus both control and CRD I. Blood urea nitrogen and creatinine levels were uniformly elevated in CRD plasma. The abundance of eNOS protein was unaffected by plasma.

CONCLUSION

High plasma levels of ADMA in CRD patients are independent of reduced renal clearance, suggesting an alteration in ADMA synthesis and/or degradation. High ADMA is a marker and is partly responsible for the inhibition of eNOS activity in cultured cells and may also result in reduced eNOS activity in vivo, with consequent hypertension.

The rabies virion-associated 100-kDa polypeptide (VAP100) is a host-derived minor component of the viral envelope

We investigated a minor polypeptide component of 100-kDa detected in the rabies virion (referred to as VAP100) by using a monoclonal antibody (mAb), #16743, which was shown to recognize the SDS-denatured VAP100 antigen by immunoblot analyses. Although the VAP100 antigen was hardly detectable in the cell by usual immunoblot methods with this mAb, we could detect the antigen by a luminescent immunoblot method as well as by immunoprecipitation from the metabolically radiolabeled cell lysates and virions. Fluorescent antibody (FA) staining with mAb #16743 detected the uniformly distributed antigen on the formalin-fixed normal BHK-21 cells, while slight accumulation of the antigen was also seen in the Golgi area when the cells were permeabilized by treatment with Triton X-100 after fixation. Rabies virus infection induced alteration of the behavior of VAP100 to show a spotted distribution pattern in virus-infected cells. Double FA staining with mAb #16743 and rabbit antibody against the rabies virus envelope antigen demonstrated colocalized distribution of the viral envelope antigens and VAP100 in the cell. From these results, we think that VAP100 is a membrane-associated component of the cell, and its colocalized distribution with the viral envelope antigens in the cell implicates an intimate association of the VAP100 with viral envelope protein(s) and a reflection of possible involvement in the efficient incorporation of VAP100 into the virion.

Synthesis and biological evaluation of DNA targeting flexible side-chain substituted beta-carboline derivatives

A series of 3-substituted-beta-carboline derivatives was synthesized from L-tryptophan. The intercalating binding mode of these compounds with DNA, the effects of the flexible alkylamine side chain on the intercalating ability and their antitumor activity were studied, which agreed well with the molecular modeling results.

Dentinogenesis imperfecta 1 with or without progressive hearing loss is associated with distinct mutations in DSPP

Dentinogenesis imperfecta 1 (DGI1, MIM 125490) is an autosomal dominant dental disease characterized by abnormal dentin production and mineralization. The DGI1 locus was recently refined to a 2-Mb interval on 4q21 (ref. 1). Here we study three Chinese families carrying DGI1. We find that the affected individuals of two families also presented with progressive sensorineural high-frequency hearing loss (gene DFNA39). We identified three disease-specific mutations within the dentin sialophosphoprotein gene (DSPP) in these three families. We detected a G-->A transition at the donor-splicing site of intron 3 in one family without DFNA39, a mutation predicted to result in the skipping of exon 3. In two other families affected with both DGI1 and DFNA39, however, we identified two independent nucleotide transversions in exons 2 and 3 of DSPP, respectively, that cause missense mutations of two adjacent amino-acid residues in the predicted transmembrane region of the protein. Moreover, transcripts of DSPP previously reported to be expressed specifically in teeth are also detected in the inner ear of mice. We have thus demonstrated for the first time that distinct mutations in DSPP are responsible for the clinical manifestations of DGI1 with or without DFNA39.

Effects of estradiol and its metabolites on glomerular endothelial nitric oxide synthesis and mesangial cell growth

Reduced nitric oxide synthesis by glomerular endothelial cells and increased proliferation of glomerular mesangial cells is associated with glomerular remodeling that leads to accelerated glomerulosclerosis. Estradiol induces nitric oxide synthesis and slows the progression of renal disease. Because the estradiol metabolites 2-hydroxyestradiol and 2-methoxyestradiol are more potent than estradiol in inhibiting growth of vascular smooth muscle cells, which are phenotypically similar to mesangial cells, we compared the effects of estradiol, 2-hydroxyestradiol, and 2-methoxyestradiol on growth of glomerular mesangial cells and on basal nitric oxide synthesis by glomerular endothelial cells. In human glomerular mesangial cells, estradiol and its metabolites concentration-dependently (1 nmol/L to 10 micromol/L) inhibited serum (2.5%)-induced DNA synthesis, cell proliferation, and collagen synthesis with the order of potency being 2-methoxyestradiol > 2-hydroxyestradiol > estradiol. ICI182780 (100 micromol/L, an estrogen receptor antagonist) blocked the growth inhibitory effects of estradiol but not 2-hydroxyestradiol or 2-methoxyestradiol. Treatment with estradiol, but not 2-hydroxyestradiol and 2-methoxyestradiol, induced nitric oxide synthesis (P<0.05, assayed by the formation of (3)H-L-citrulline from (3)H-L-arginine) in human glomerular endothelial cells, and these effects were blocked by ICI182780 and L-NMA (a nitric oxide synthesis inhibitor). In conclusion, estradiol may attenuate glomerulosclerosis by inducing nitric oxide synthesis via an estrogen receptor-dependent mechanism and by conversion to 2-hydroxyestradiol and 2-methoxyestradiol, which inhibit glomerular mesangial cell proliferation independent of estrogen receptors.

Broad-spectrum mildew resistance in Arabidopsis thaliana mediated by RPW8

Plant disease resistance (R) genes control the recognition of specific pathogens and activate subsequent defense responses. We show that the Arabidopsis thaliana locus RESISTANCE TO POWDERY MILDEW8 (RPW8) contains two naturally polymorphic, dominant R genes, RPW8.1 and RPW8.2, which individually control resistance to a broad range of powdery mildew pathogens. Although the predicted RPW8.1 and RPW8.2 proteins are different from the previously characterized R proteins, they induce localized, salicylic acid-dependent defenses similar to those induced by R genes that control specific resistance. Apparently, broad-spectrum resistance mediated by RPW8 uses the same mechanisms as specific resistance.

Artemether administered together with haemin damages schistosomes in vitro

We conducted experiments in vitro to assess the effect of artemether in combination with haemin on adult Schistosoma japonicum, S. mansoni and S. haematobium. When schistosomes were maintained in a medium containing artemether at concentrations of 20 micrograms/mL or less for 72 h, no apparent effect on the schistosomes was seen. When the medium contained 50 or 100 micrograms/mL haemin as well as artemether, the schistosomes showed decreased motor activity 2-24 h after exposure, which was followed by the staining of the whole worm body a reddish-yellow colour, dilatation of the intestine, and extensive vesiculation of the tegument. Some of the schistosomes died 24 h after exposure, and almost all died within 48-72 h. When schistosomes were exposed to the same concentrations of haemin alone, they were stained a light yellow colour but there was no apparent effect on their survival. Our findings suggest that artemether interacts with haemin to exert a toxic effect on the worms, which might be of importance in the further elucidation of the mechanism of action of artemether on schistosomes.

Eumetazoan fossils in terminal proterozoic phosphorites?

Phosphatic sedimentary rocks preserve a record of early animal life different from and complementary to that provided by Ediacaran fossils in terminal Proterozoic sandstones and shales. Phosphorites of the Doushantuo Formation, South China, contain eggs, egg cases, and stereoblastulae that document animals of unspecified phylogenetic position; small fossils containing putative spicules may specifically record the presence of sponges. Microfossils recently interpreted as the preserved gastrulae of cnidarian and bilaterian metazoans can alternatively be interpreted as conventional algal cysts and/or egg cases modified by diagenetic processes known to have had a pervasive influence on Doushantuo phosphorites. Regardless of this interpretation, evidence for Doushantuo eumetazoans is provided by millimeter-scale tubes that display tabulation and apical budding characteristic of some Cnidaria, especially the extinct tabulates. Like some Ediacaran remains, these small, benthic, colonial fossils may represent stem-group eumetazoans or stem-group cnidarians that lived in the late Proterozoic ocean.

CD95 (Fas) ligand-expressing vesicles display antibody-mediated, FcR-dependent enhancement of cytotoxicity

Bioactive Fas ligand (FasL)-expressing vesicles were generated (vesicle preparation, VP) from two cell lines overexpressing FasL. The effect of NOK-1 anti-FasL mAb (mouse IgG1) on the cytotoxicity of FasL VP against various targets was determined. At high concentrations (1-10 microg/ml), NOK-1 inhibited the cytotoxicity. By contrast, NOK-1 in the dose range of 1-100 ng/ml significantly enhanced cytotoxicity against the FcR(+) LB27.4, M59, and LF(+) targets, but not the FcR(-) Jurkat and K31H28 hybridoma T cell targets. The ability to enhance FasL VP-mediated cytotoxicity could be blocked by the FcR-specific mAb 2.4G2. Enhancement was also observed with FcR(+) A20 B lymphoma but not with the FcR(-) A20 variant. Enhancement of FasL VP cytotoxicity was observed with five IgG anti-FasL mAbs, but not with an IgM anti-FasL mAb. Inhibition was observed with high doses of all mAb except the IgG anti-FasL mAb G247-4, which is specific to a segment outside the FasL binding site. Interestingly, under identical conditions but in the presence of 2.4G2, G247-4 inhibited the cytotoxicity of FasL VP. In addition, G247-4 inhibited the FasL VP-mediated killing of FcR(-) Jurkat. The data demonstrate that FasL-expressing bioactive vesicles display a property heretofore unknown in bioactive agents that express FasL-mediated cytotoxicity. The mechanism of the Ab-mediated, FcR-dependent enhancement of cytotoxicity of bioactive vesicles and its physiological significance are discussed.

Non-steroidal anti-inflammatory drug toxicity in the upper gastrointestinal tract

Non-steroidal anti-inflammatory drug (NSAID) toxicity in the upper gastrointestinal tract is the most common serious drug-induced toxicity reported to drug regulatory authorities. In the last two decades, the rediscovery of H. pylori, development of potent ulcer-healing drugs and specific Cox-II inhibitors have opened new horizons in the management of NSAID toxicity. A Working Party composed of gastroenterologists and rheumatologists in the Asia-Pacific region met in Cairns, Australia, in 1999 to review the literature and develop appropriate guidelines. Recommendations were made based on the latest existing evidence. The importance of clinical events as study endpoints was emphasized. While differences exist between NSAIDs and aspirin, most studies have shown that advanced age, history of peptic ulcer disease, serious concomitant illnesses and coprescription of NSAID/aspirin with anticoagulants and steroids are high risk factors. These patients should be considered for prophylactic anti-ulcer therapy. Helicobacter pylori infection may aggravate the toxicity of NSAIDs and, in selected cases, should be treated before NSAID/aspirin is prescribed. Proton pump inhibitors and misoprostol are the most promising agents in preventing gastric and duodenal ulcers. When NSAID/aspirin needs to be continued in patients who develop an NSAID-related ulcer, proton pump inhibitors offer the best healing effect. With the discovery of cyclo-oxygenase isoforms (Cox-I and Cox-II), preferential and specific Cox-II inhibitors have been developed. While early clinical data have suggested promising antiinflammatory effects and improved safety profile in the gastrointestinal tract, several key issues on long-term safety remain unresolved. The use of potent anti-ulcer therapy, treatment of H. pylori infection and the development of Cox-II inhibitor will change the scenario of NSAID/aspirin-related gastrointestinal toxicity in the next millennium.

Tegumental changes in adult Schistosoma mansoni harbored in mice treated with artemether

A detailed temporal examination was made of alterations induced by artemether in the tegument of adult Schistosoma mansoni worms using scanning electron microscopy (SEM). Mice infected with S. mansoni cercariae 42 days previously were treated intragastrically with artemether at a single dose of 400 mg/kg. Groups of 3 mice were killed at 24 hr, 72 hr, and 7 days after treatment; the worms were collected by perfusion and examined by SEM. Twenty-four hours after artemether treatment, focal damage to the tubercles on the tegumental surface of male worms was seen. In both male and female worms, there was focal swelling and fusion of tegumental ridges, and sometimes peeling. After 72 hr, the damage to the tegument had increased, especially in female worms, with extensive swelling, fusion, and peeling of the tegumental ridges. In the most severely damaged worms, host leukocytes were seen to be adhered to the damaged tegument. Damage to the oral sucker was also occasionally seen in both male and female worms. Seven days after treatment, the appearance of the tegument had returned to normal in some male and female worms, whereas others still showed apparent damage. The results demonstrate that artemether damages the tegument of adult S. mansoni, and the intensity of damage is more severe in female worms than in males.

The relationship between angiotensinogen gene CD235 met-->Thr substitution polymorphism and brain infarction in Chinese

OBJECTIVE

To detect the relationship between angiotensinogen (AGT) gene CD235 Met-->Thr substitution polymorphism and brain infarction.

METHODS

The CD235Met-->Thr substitution polymorphism in exon 2 of AGT gene was analyzed in normal group(82 cases) and brain infarction group (102 cases) by a combination of polymerase chain reaction-restriction fragment length polymorphism(PCR-RFLP).

RESULTS

Between the control group and brain infarction group, chi-square test showed no significant difference in the frequencies of T/T genotype and T allele (P>0.05). However, the frequencies of T/T genotype and T allele (70.6% and 83.8%) for multiple brain infarction patients were higher than those (42.6% and 65.2%) for lacunae brain infarction patients and those (42.0% and 65.2%) for controls (P<0.01). The frequencies of AGT T/T genotype and T allele (65.3% and 78.6%) for patients with brain infarction associated with hypertension were higher than those (42.0% and 65.0%) for patients with brain infarction not associated with hypertension (P<0.05).

CONCLUSION

No direct relationship between AGT CD235 Met-->Thr substitution polymorphism and ordinary brain infarction has been observed, but there is a significant correlation between AGT gene T/T genotype and multiple brain infarction, and brain infarction associated with hypertension too.

Refinement of the locus for autosomal dominant hereditary gingival fibromatosis (GINGF) to a 3.8-cM region on 2p21

Hereditary gingival fibromatosis (HGF, MIM 135300; approved gene symbol GINGF) is an oral disease characterized by enlargement of gingiva. Recently, a locus for autosomal dominant HGF has been mapped to an 11-cM region on chromosome 2p21. In the current investigation, we genotyped four Chinese HGF families using polymorphic microsatellite markers on 2p21. The HOMOG test provided evidence for genetic homogeneity, with evidence for linkage in four families (heterogeneity versus homogeneity test HOMOG, chi(2) = 0. 00). A cumulative maximum two-point lod score of 5.04 was produced with marker D2S390 at a recombination frequency of &theta; = 0 in the four linked families. Haplotype analysis localized the hereditary gingival fibromatosis locus within the region defined by D2S352 and D2S2163. This region overlaps by 3.8 cM with the previously reported HGF region. Single-strand conformation polymorphism and sequence analysis of the coding region of cytochrome P450 1B1 (CYP1B1) excluded it as a likely candidate gene.

[An analysis of precision and accuracy of the phonocardiogram exercise test]

Phonocardiogram exercise testing (PCGET) is a recently developed method to evaluate cardiac contractility and the cardiac reserve of patients with heart disease and of healthy subjects. In order to test the reliability of PCGET method, the present author conducted a study on its precision and accuracy. Thirty volunteers underwent PCGET. When different examiners measured the S1 amplitude in the same cardiac cycle of the same subject, the data obtained by examiner A were: x +/- s = 5.05 +/- 0.0451; the data obtained by examiner B were: x +/- s = 4.95 +/- 0.0346, F = 1.699, P > 0.05. When different examiners measured the same cardiac cycle of the same subject, the data obtained by examiner A were: x +/- s = 0.789 +/- 0.0018; the data obtained by examiner B were: x +/- s = 0.787 +/- 0.0017, F = 1.167, P > 0.05. The results suggest that PCGET is a nonivasive, convenient, and inexpensive technique to quantitatively evaluate cardiac reserve for abnormal or normal persons.

PLAG1 fusion oncogenes in lipoblastoma

Lipoblastomas are pediatric neoplasms resulting from transformation of adipocytes. These benign tumors are typically composed of adipose cells in different stages of maturation within a variably myxoid matrix, and they contain clonal rearrangements of chromosome band 8q12. Because lipoblastomas resemble embryonic adipose tissue, characterization of their transforming mechanisms might reveal biological pathways in physiological adipogenesis. Herein, we demonstrate that lipoblastoma chromosome 8q12 rearrangements bring about promoter-swapping events in the PLAG1 oncqgene. We show that the hyaluronic acid synthase 2 (HAS2) or collagen 1 alpha 2 (COL1A2) gene promoter regions are fused to the entire PLAG1 coding sequence in each of four lipoblastomas. PLAG1 is a developmentally regulated zinc finger gene whose tumorigenic function has been shown previously only in epithelial salivary gland cells. Our findings reveal that PLAG1 activation, presumably resulting from transcriptional up-regulation, is a central oncogenic event in lipoblastoma.

Digital filter design for peak detection of surface EMG

A simple Low-Pass Differential (LPD) filter is often used for the Motor Unit Action Potential (MUAP) peak detection in needle EMG decomposition. Decomposition of surface EMG is much more difficult since surface EMG is more mixed than needle EMG. A successful peak detection of MUAPs is a first important step for EMG decomposition. We found that a simple LPD filter is not suitable for surface MUAP detection; instead the Weighted Low-Pass Differential (WLPD) filters are proposed. The filter performance is analyzed based on different window selection and varying MUAPs from simulated and recorded surface EMG. The sinusoidal WLPD filter is found to have better SNR improving factors, and to be more robust under the varying conditions.

[Study on green upconversion luminescence of fluoride glasses doped with Nd3+]

In this paper, we report the upconversion luminescence of Nd: fluoride glasses pumped with 858 nm diode laser. Among the observed upconversion spectra, the green emission concerning with three photon process has overwhelming superiority in intensity, when the doping concentration of Nd3+ is enhanced, the green upconversion emission increases more drastically than that of other upconverted emissions. The experiment results indicate that fluoride glasses doped with Nd3+ posssess possibility of being green emitting upconversion materials. When the upconversion mechanism is discussed, the green luminescence concerning with three-photon is ascribed to three-ion cooperative upconversion.

Effect of artemether against Schistosoma haematobium in experimentally infected hamsters

The drug, artemether, has been shown to be active against the juvenile stages of Schistosoma japonicum and Schistosoma mansoni in experimentally infected animals, while it is less effective on adult worms. These findings have been confirmed in randomised controlled trials in humans. Consequently, it could be expected that artemether is also active against Schistosoma haematobium. We present here the first results from experiments assessing the effect of artemether on S. haematobium. Hamsters with a single infection received intra-gastrically an initial dose of 300 mg/kg artemether on day 14, 21 or 28, followed by further doses at varying treatment regimens. In all the treatment groups, the total and female worm reduction rates were highly significant, and ranged from 78 to 100% in hamsters harbouring juvenile schistosomes. Hamsters infected three times with S. haematobium, on days 0, 4 and 9, and repeatedly treated with artemether at the same dose as above, showed highly significant total and female worm reduction rates of between 94 and 99%. Artemether was also active against 77-day-old adult S. haematobium, since its administration on two consecutive days resulted in highly significant total and female worm reduction rates of 76-89%. Our findings confirm that artemether is also active against S. haematobium, especially the schistosomules. These results provide a basis for clinical trials in humans, for further assessment of the potential of artemether for schistosomiasis control.

ZNF198-FGFR1 transforming activity depends on a novel proline-rich ZNF198 oligomerization domain

An acquired chromosomal translocation, t(8;13)(p11;q11-12), observed in a distinctive type of stem cell leukemia/lymphoma syndrome, leads to the fusion of the 5' portion of ZNF198 and the 3' portion of FGFR1. ZNF198-FGFR1 fusion transcripts encode 4 to 10 zinc fingers, a proline-rich region, and the intracellular portion of the FGFR1 (fibroblast growth factor receptor 1) receptor tyrosine kinase. We demonstrate that the ZNF198 proline-rich region constitutes a novel self-association domain. When fused to the intracellular domain of FGFR1, the ZNF198 proline-rich region is sufficient to cause oligomerization, FGFR1 tyrosine kinase activation, and transformation of Ba/F3 cells to IL-3 independent growth. (Blood. 2000;96:699-704)

Transfection and expression of HCV-NS5B gene in Huh-7 cells

OBJECTIVE

To study the mechanism of hepatitis C virus (HCV) replication and to test gene therapy for hepatitis C, a human liver cell line expressed HCV RNA polymerase has been established.

METHODS

NS5B gene has been transfected into Huh-7 cells by lipofectamine. The results of transfection were confirmed by PCR and Southern blot analysis, and the level of the non-structural protein 5B (NS5B) in Huh-7 cells was detected by Western blot analysis.

RESULTS

There were NS5B gene fragments and the expression of NS5B protein in Huh-7c cells transfected with pTeT-NS5B or pcDNA-NS5B plasmid.

CONCLUSIONS

We have established a HCV RNA polymerase expression system in Huh-7 cells which can be further used to analyze the mechanism of HCV replication and provide a cell model for gene therapy in vitro.

Tegumental changes in 21-day-old Schistosoma mansoni harboured in mice treated with artemether

Alterations in the tegument of 21-day-old Schistosoma mansoni, caused by artemether administered to the infected mice, were studied using scanning electron microscopy (SEM). Mice were infected with S. mansoni cercariae, and after 21 days a single dose of artemether (400 mg/kg) was administered intragastrically. After 24, 72 h and 7 days groups of three mice were killed and the schistosomules collected by perfusion, fixed and processed routinely, and examined by SEM. After 24 h, all male and female worms examined showed alterations in the tegument, characterised by swelling, vesiculation and fusion of tegumental ridges; peeling, erosion and collapse of damaged tegumental surface, and also destruction of the oral sucker and acetabulum. After 72 h, severe damage to the tegument was seen, usually including extensive peeling, swelling and vesiculation, and host leukocytes were adhered to the damaged surface. Some worms were surrounded by clusters of host leukocytes or had even disintegrated. Seven days after treatment, some schistosomules still showed severe tegumental damage, but in some cases the damage was less than at earlier times, which suggested that those schistosomules that had survived were beginning to recover. The ability of artemether to cause severe damage to the tegument correlates with its high efficacy in killing 21-day-old schistosomules.

Oral artemether for prevention of Schistosoma mansoni infection: randomised controlled trial

BACKGROUND

Chemotherapy with praziquantel is the current strategy of choice to control schistosomiasis. However, in view of concern about praziquantel tolerance or resistance, new drugs are needed. Artemether, a derivative of the antimalarial drug artemisinin, kills immature schistosomes of Schistosoma japonicum, and reduces the incidence of infection in field trials. Laboratory studies have also showed activity by this drug against S. mansoni. We report a randomised double-blind placebo-controlled clinical trial of artemether to prevent S. mansoni infection.

METHODS

The trial was done in an area of western Côte d'Ivoire endemic for S. mansoni. 354 schoolchildren were enrolled. Stool specimens were screened over four consecutive days, followed by two mass treatments with praziquantel 4 weeks apart. All S. mansoni negative children were randomly assigned to placebo (n=151) or artemether 6 mg/kg (n=138) orally six times once every 3 weeks. Adverse events were assessed 24 h after treatment. Perceived illness episodes were recorded once a week by interviewing the children with a standardised questionnaire. 3 weeks after the final medication S. mansoni infections were assessed by screening stool samples. Blood samples were examined for Plasmodium falciparum before the first and after the last artemether treatment.

FINDINGS

Oral artemether showed no adverse reactions. The group that received artemether had a significantly lower incidence of S. mansoni infection (31/128 versus 68/140, relative risk: 0.50 [95% CI 0.35-0.71], p=0.00006). The geometric mean egg output among positive children in the artemether group was significantly lower than in placebo recipients (19 vs 32 eggs/g stool, p=0.017). There was also a significant reduction in the prevalence of P. falciparum.

INTERPRETATION

Oral artemether is safe and shows a prophylatic effect against S. mansoni. The use of artemether may be recommended in appropriated situations as an additional tool for more effective schistosomiasis control measures. However the application needs to be carefully assessed especially in view of the concern that it could select for resistant plasmodia.

Role of activator protein-1 in TCR-mediated regulation of the murine fasl promoter

The present study demonstrates that transcription factor interactions are important in regulating the murine fasl promoter following TCR-mediated activation. We used DNase I-footprinting, EMSAs, and transient transfection assays to identify the minimal TCR signal-responsive region within the fasl promoter. This region contains the previously identified binding sites for NF-kappaB and Egr and the AP-1 site identified in this study. We found that TCR signaling induces AP-1 binding to this site and regulates the fasl promoter function in a fashion dependent on NF-kappaB binding. However, mutation in the AP-1 site alone did not show a significant effect on the promoter function. The data suggest that the minimal promoter required at least two transcription factors to function.

KIT extracellular and kinase domain mutations in gastrointestinal stromal tumors

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal neoplasms arising in the gastrointestinal tract. GISTs express the KIT receptor tyrosine kinase, and many cases have activating mutations in the KIT juxtamembrane region. We now report an analysis of KIT cDNA and genomic sequences in eight GISTs that lack juxtamembrane region mutations. Six cases contained heterozygous exon 9 mutations in which six nucleotides, encoding Ala-Tyr, were duplicated. The other two cases contained homozygous exon 13 missense mutations, resulting in substitution of Glu for Lys(642), that were associated with constitutive KIT tyrosine phosphorylation. Sequence analysis of DNAs from nonneoplastic companion tissues revealed that both the exon 9 and exon 13 mutations were somatic. These are the first descriptions, in any tumor, of mutations in KIT exons encoding the C-terminal end of the extracellular domain and the first part of the split kinase domain. These findings indicate that KIT may be activated by mutations in at least three domains-extracellular, juxtamembrane, and kinase-in GISTs.

[The influence of external stimulation on content and quality of volatile oil in Lignun Santali albi]

The authors analyzed the quality of Ligmum Santali Albi formed by the external stimulation of hormone and windburn by GC-MS-DS. The results showed that the content of volatile oil is 2.34% in the heart wood formed in 10 years tree age of Santalum album (SA) after 2 years stimulation continuously with a definite concentration of hormone, which is near to the 25 years tree age of SA in the same place. The GC-MS analysis showed that the content of santalol and other chemical components in volatile oil are similar to the 25 years tree age of SA. It is indicated that a definite concentration of hormone stimulated the SA may shorten the formation of the heart wood. The heart wood can be also formed by the broken branches after 2 years windburn, but its content of volatile oil is only 1/2 of the heart wood formed by hormone stimulation.

Plasma from ESRD patients inhibits nitric oxide synthase activity in cultured human and bovine endothelial cells

Our recent observations of reduced total nitric oxide synthesis in renal failure patients on peritoneal dialysis and haemodialysis suggest that hypertension in end-stage renal disease involves lack of vasodilatory endothelial NO. To directly test this, uraemic plasma was obtained from dialysis patients and incubated with cultured vascular endothelial cells, to determine the effect on nitric oxide synthase (NOS) activity in comparison with plasma from subjects with normal renal function. After incubation for 6 h with 20% uraemic plasma from peritoneal dialysis and immediately prehaemodialysis patients, NOS activity was reduced in human dermal microvascular endothelial cells. Haemodialysis did not remove the NOS-inhibitory activity of uraemic plasma nor did it activate inducible NOS, as NOS activity was always similar in control and dexamethasone pretreated cells. Nitric oxide production (accumulation of nitrite and nitrate) was lower in cells incubated with uraemic vs. normal plasma and excess arginine increased nitric oxide production by cells previously exposed to uraemic medium. This inhibitory effect was not associated with co-factor deficiency but did correlate with plasma concentrations of endogenous NOS inhibitors. These in vitro findings suggest that low endothelial NOS activity may contribute to hypertension in end stage renal disease patients.

Analysis of related factors in complications of stereotactic radiosurgery in intracranial tumors

OBJECT

To investigate the related factors in complications of stereotactic radiosurgery for intracranial tumors.

METHODS

A retrospective review of 146 patients with intracranial tumors treated with stereotactic radiosurgery was conducted. Sixty-five patients received single-dose treatment and the rest received fractionated stereotactic radiosurgery. Ninety-five patients received conventional radiotherapy in the meantime.

RESULTS

Follow-up period was 18-54 months. Follow-up rate was 92.5% and 39 patients (26.7%) had different complications. The Cox statistics showed that target volume, target peripheral dose, target maximal dose, and ratio of maximal dose to peripheral dose are related to the complications. Conversely, neither type of tumor disease, gender, radiation schedule with or without conventional radiotherapy, target minimal dose, nor ratio of target peripheral isodose volume to target volume were found to be related to complications.

CONCLUSION

Target volume and dose are the major factors causing complications, and the optimization of the therapeutic planning can play a significant role in reducing them.

Clinical and CT histological diagnosis of orbital tumors

The clinical manifestation and characteristics of CT image of 117 cases of orbital tumors in our hospital were investigated. The hemangioma had the highest incidence, and the less common tumors were, in sequence of incidence, pseudotumor, dermoid cysts, neurilemmoma, polymorphous adenoma and meningioma. The sensitivity in diagnosis of orbital tumor by CT was 93.3%. The coincidence of CT histological diagnosis with pathology were 83.3%, 82.6% and 71.4% for dermoid cysts, hemangioma, and pseudotumor respectively, but the general coincidence of CT histological diagnosis with pathology was only 67.8%. When CT was combined with ultrasound, cytological examination and clinical manifestations, the accuracy of histological diagnosis could be improved to 83.3%.

Length of protection by murine vaccination with living infective third-stage hookworm larvae

OBJECTIVE

To determine the length of protection by murine immunization with living third-stage hookworm larvae (L3) as measured by reduction in worm burden and host serologic antibody responses.

METHODS

Outbred male (Kunming strain) mice were immunized subcutaneously with 500 L3 once every 2 weeks for a total of immunization for 3 times, and then challenged orally with 1000 L3 for 1 to 8 weeks after the final immunization. Host protective immunity was determined both by the reduction in worm burden as measured by the number of L3 recovered from murine lungs 48-hour post-challenge, as well as by measurement of circulating antibodies. Histopathological responses were also examined. Non-immunized mice served as negative controls.

RESULTS

The protection by L3 immunization declined over time. One or 2 weeks after the final immunization, worm burdens were reduced 72% and 77.5% after challenge respectively. In contrast, only 37% reduction in worm burden was observed when the L3 challenge was delayed by 4 weeks and protection was almost entirely lost when there was an 8 week delay between the time of final immunization and challenge. The reduced level of protection over time partially correlated with diminishing L3-specific antibody responses. Host inflammation in the lungs of immunized mice also diminished.

CONCLUSION

The protection afforded by living L3 immunization is maximal for the first two weeks after immunization, but then declines significantly over the ensuing weeks.

Comparison of Erysiphe cichoracearum and E. cruciferarum and a survey of 360 Arabidopsis thaliana accessions for resistance to these two powdery mildew pathogens

In previous work, UEA1 and UCSC1, two geographically distinct, powdery mildew isolates, were recognized for their ability to infect Arabidopsis thaliana. We have clarified the identity of these isolates by determining their host ranges, reexamining their morphology, and comparing their DNA sequences for the 5.8S ribosomal RNA and two flanking internal transcribed spacer sequences. These experiments confirm that UEA1 is a member of Erysiphe cruciferarum and that UCSC1 belongs to E. cichoracearum. Interactions of the two Erysiphe isolates with 360 A. thaliana accessions were examined to provide a comprehensive profile of naturally occurring powdery mildew resistance in this weedy species. The majority of A. thaliana accessions (213) were susceptible to both isolates. Among the accessions exhibiting some degree of resistance, most (84) responded differentially to UEA1 and UCSC1 and the remainder were resistant to both isolates. Notably, resistance to UCSC1 cosegregated with RPW7, a locus previously demonstrated to confer resistance to UEA1 in Ms-0 x Landsberg (erecta) crosses. With this large collection of resistant accessions, questions about species specificity, genetic diversity and the evolution of resistance to powdery mildews can be addressed.

[DNase I sensitivity of nucleus and chromatin in six different tissues of old rates]

In order to investigate the mechanism of aging, we studied the DNase I sensitivity of nucleus and chromatin in six different tissue (heart, liver, spleen, lung, kidney and brain of old and weanling wistar rats. The results showed that the DNase I digestive sensitivity levels of nucleus and chromatin in the tissue of the old rats were lower than those of the weanling rats respectively that in the old rats, the DNase I digestive sensitively in the tissue varied, the lowest sensitivity was in brain (P < 0.01); and that in the weanling rats, lowest DNase I digestive sensitivity of nucleus and chromatin was also in the brain, but the difference was not significant.

FasL promoter activation by IL-2 through SP1 and NFAT but not Egr-2 and Egr-3

Recently activated peripheral T cells treated with IL-2 for 4 days expressed Fas ligand (FasL)-mediated cytotoxicity. These IL-2-treated T cells had high nuclear expression of SP1 and NFAT, but lacked the Egr-2 and Egr-3 that could be induced by anti-CD3 stimulation and had been implicated in FasL gene activation. A minimal promoter region that responded to IL-2 was identified by transient transfection assays using deletion mutants. The data suggests that the GGGCGGAAA site present in the 5' end of the minimal FasL promoter is critical to IL-2-induced FasL gene activation. The GGGCGGAAA sequence contains an overlapping site used by two transcription factor families, one (GGGCGG) for the SP1 family and the other (GGAAA) for the NFAT family. FasL promoter activity was partially but statistically significantly reduced with constructs mutated at either site. More activity was lost with a construct mutated at both sites. In contrast, mutation at the Egr site had no effect on IL-2-induced FasL promoter activity. Our study identified a new FasL promoter site responding to IL-2-induced SP1 and NFAT factors. Furthermore, the nuclei of IL-2-treated cells express SP1 and NFAT, but not Egr-2 and Egr-3, for FasL gene activation.

Cutaneous and subcutaneous mast cell and eosinophil responses after challenge in mice vaccinated with living infective third-stage hookworm larvae

OBJECTIVE

To examine the quantitative and qualitative alterations in mast cells and eosinophils distributed in the cutaneous and subcutaneous tissues of hookworm-infected, uninfected and vaccinated mice.

METHODS

Outbred male Kunming strain mice, weighing 18-22 g, were vaccinated thrice by subcutaneous inoculation with 500 living third-stage infective larvae (L3) of Ancylostoma caninum (A. caninum) every 2 weeks, and then challenged subcutaneously with 500 L3 one week after the final immunization. Uninfected mice and non-immunized mice but infected with L3 served as controls. The abdominal skin at the site of percutaneous entry was excised from challenged mice at intervals between 6 hours and 7 days after challenge, fixed, and then examined by light microscopy after staining with either toluidine blue or hematoxylin and eosin.

RESULTS

The total number of mast cells appearing in cutaneous, and subcutaneous tissues, and underlying abdominal musculature of immunized mice increased significantly compared with non-immunized mice. Mast cells from hookworm-infected mice showed evidence of membrane rupture and degranulation in contrast to the intact appearance of mast cells from uninfected mice. The degree of mast cell degranulation was greater in vaccinated and challenged mice when compared with non-immunized and infected mice. Similarly, eosinophilic infiltration was greatly enhanced after L3 infection. Tissues from vaccinated mice had a greater number of eosinophils than non-immunized mice after infection.

CONCLUSIONS

Mast cell alterations appearing earlier than tissue eosinophilic infiltration is major inflammatory response to Ancylostoma caninum (A. caninum) L3 infection in mice. These processes are more obvious in L3-vaccinated mice.

Caring attributes, professional self concept and technological influences in a sample of Registered Nurses in eleven countries

Caring, the theoretical foundation of nursing, is identified as one of the core values by Hospital Authorities world-wide to be actualised in clinical practice. Exactly how caring attributes relate to nurses' professional self image and quality nursing service in the context of a contemporary technological environment have yet to be operationalised. In total, 1957 Registered Nurses from 11 different countries were involved in the study which aimed to: develop an understanding of and compare the responses to items relating to caring, professional self concept and technological influences. To collect data an instrument containing 104 Likert items was administered to RNs working in general hospitals. The instrument contained sections which examined professional self concept, technological influences and caring attributes. Descriptive and inferential statistics revealed that many of the Asian nurses in the sample were younger, had less experience yet were more qualified than their 'western' colleagues. The mean scores for the caring attributes for nurses from the Philippines, Sweden and South Africa were significantly higher than those from China (Beijing), Korea, China (Hong Kong) and Scotland. The Korean sample demonstrated the lowest mean score for professional self concept while the New Zealand sample the highest. The Australian, Canadian, NZ, Scotland and Swedish samples were strongly of the opinion that the increase in technology has not brought about the any more spare time in nursing and generally had a more negative opinion about the influence of technology when compared to those from China (Beijing), Philippines, China (Hong Kong) and Singapore. The results are discussed in the light of the cultural differences in the sample and recommendations for future research are considered.

Alcohol consumption and alcohol-related problems: Chinese experience from six area samples, 1994

AIMS

To understand the drinking frequency, mean yearly volume of consumption and drinking-related problems in individuals living in six areas in China.

DESIGN AND MEASUREMENTS

By two-stage sampling, 23,513 community household residents (15-65 years old) were assessed with data collected by trained psychiatrists using structured questionnaires and DSM-III-R criteria.

FINDINGS

The male, female and total drinking rates were 84.1%, 29.3% and 59.5%, respectively. More than half of male drinkers and 90.0% of female drinkers used alcohol once a week or less. More than 16.1% of male drinkers and 2.5% of female drinkers drank once a day or more. The males reported a greater amount of alcohol consumed per session. The mean yearly volume of consumption of pure alcohol per year for all sample was 3.60 l; males consumed 18.6 times more alcohol than females. The rate of alcohol-related problems was higher in males than females. The male, female and total alcohol dependence point prevalence rates were 6.632%, 0.104% and 3.428%, respectively. Six-month incidence rates of acute intoxication were 5.162% 0.017% and 2.637%, respectively.

CONCLUSION

Drinking problems in China will continue to be a public health problem in the next century.

Folylpoly-gamma-glutamate synthetase: generation of isozymes and the role in one carbon metabolism and antifolate cytotoxicity

A single human gene encodes both mitochondrial and cytosolic isoforms of the enzyme. The major mRNA species in human cells encodes the mitochondrial isoform but alternate translation initiation at a downstream in-frame ATG also generates the cytosolic isoform. Cytosolic FPGS may also be generated by use of alternate transcription initiation start sites 3' to the start ATG of the mitochondrial FPGS. Three additional human FPGS mRNAs differing in exon 1 have been identified. One of these is a major species in HEP-G2 cells and other tissue culture cells, and can encode a protein lacking the first 8 amino acids of cytosolic FPGS. A protein of the predicted size is observed in coupled transcription/translation systems. However, expression of this protein in E. coli does not generate an active enzyme. Mutagenesis studies indicate that Tyr-3 of the missing N terminal residues is required for enzyme activity. The major cellular folate pools are in the cytosol and mitochondria and FPGS activity is normally distributed in both compartments. Mitochondrial FPGS activity is required for mitochondrial folate accumulation, and cells lacking this isozyme are auxotrophic for glycine. Overexpression of cytosolic FPGS does not complement the lack of mitochondrial activity. Cells expressing FPGS activity solely in the mitochondria are glycine prototrophs, but also possess cytosolic folylpolyglutamates and are prototrophic for thymidine and purines, products of cytosolic one carbon metabolism. Although cytosolic folylpolyglutamates cannot enter the mitochondrion, mitochondrial folylpolyglutamates are released intact into the cytosolic compartment. Cellular accumulation of some antifolates and their cytotoxic efficacy is highly responsive to the level of FPGS activity. Polyglutamylation of methotrexate (MTX) has little affect on its affinity for dihydrofolate reductase, its target enzyme, but does affect the cellular accumulation of the drug. The sensitivity of model cells, expressing a range of FPGS activities similar to that observed in leukemia blasts, to MTX varied over four orders of magnitude. MTX toxicity was dependent on cytosolic FPGS activity as this drug does not enter the mitochondria, and cells expressing very high levels of FPGS solely in the mitochondria were resistant to MTX. The cytotoxic efficacy of other folate antagonists that are transported into the mitochondria was enhanced by mitochondrial FPGS activity, even when their loci of inhibition was a cytosolic enzyme. Mitochondrial metabolism of these drugs increased cytosolic drug levels. Compartmentalization of antifolate metabolism has to be considered in evaluating mechanisms for increased drug cytotoxicity and for the development of acquired resistance to these agents.

Hypothesis: A recurrent, moderate activation fosters systemic autoimmunity--the apoptotic roles of TCR, IL-2 and Fas ligand

Studies of several gene knockout mice suggest an interesting association of a moderate T cell response with systemic autoimmune diseases. In addition, CD95 ligand (FasL) expression in some strains of these mice is impaired. Because FasL is critically involved in regulating peripheral tolerance, there may be a link between autoimmune diseases and a moderate T cell response that cannot activate the FasL gene. Here, we propose that there are two thresholds of T cell activation. When moderately stimulated, T cells can be activated to the low (1st) threshold, which permits the induction of CD40L, IL-2, IL-4, and other components that help the immune response. The high (2nd) activation threshold can only be achieved by a strong and concurrent stimulation through TCR and IL-2R. Once the high threshold is reached, FasL is produced to induce apoptosis of the activated T and B cells. In the absence of the FasL-mediated downregulation, the activated B cells become efficient antigen-presenting cells for self-antigens and excellent responders for T cell help. Such an exacerbating condition, induced by recurrent and moderate activation, favors the development of autoreactive T cells and autoantibody production. Evidence supporting this hypothesis and some predictions that can be tested are described.