[A survey of pollens in Chongqing]

OBJECTIVE

In order to investigate the variety of the airborne pollen in Chongqing.

METHOD

The diffusions pattern of airborne pollens in two areas of Chongqing was investigated for one year from October 1999 to September 2000. The slides were exposed daily through one year.

RESULT

The peak of spreading was in March in spring and in Autumn from September to October. The test on the pollen patients shows that the main resulting pollen is in Autumn.

CONCLUSION

The airborne pollen peak in Chongqing in spring prone to the influence of temperature, wind power and rain amount.

Surface organization and nanopatterning of collagen by dip-pen nanolithography

Collagen is a key fibrous protein in biological systems, characterized by a complex structural hierarchy as well as the ability to self-assemble into liquid crystalline mesophases. The structural features of collagen influence cellular responses and material properties, with importance for a wide range of biomaterials and tissue architectures. The mechanism by which fibrillar collagen structures form from liquid crystalline mesophases is not well characterized. We report positive printing of collagen and a collagen-like peptide down to 30-50-nm line widths, using the atomic force microscopy technique of dip-pen nanolithography. The method preserved the triple-helical structure and biological activity of collagen and even fostered the formation of characteristic higher levels of structural organization. The "direct-write" capability of biologically relevant molecules, while preserving their structure and functionality, provides tremendous flexibility in future biological device applications and in proteomics arrays, as well as a new strategy to study the important hierarchical assembly processes of biological systems.

Activation of p21(WAF1/Cip1) transcription through Sp1 sites by histone deacetylase inhibitor apicidin: involvement of protein kinase C

We previously reported that apicidin, a novel histone deacetylase inhibitor, inhibited the proliferation of tumor cells via induction of p21(WAF1/Cip1). In this study, we determined the molecular mechanisms by which apicidin induced the p21(WAF1/Cip1) gene expression in HeLa cells. Apicidin induced p21(WAF1/Cip1) mRNA independent of the de novo protein synthesis and activated the p21(WAF1/Cip1) promoter through Sp1-3 site located at -82 and -77 relative to the transcription start site. This transcriptional activation appears to be mediated by protein kinase C (PKC), because calphostin C, a PKC inhibitor, significantly attenuated the activation of p21(WAF1/Cip1) promoter via Sp1 sites, which was accompanied by a marked suppression of p21(WAF1/Cip1) mRNA and protein expression induced by apicidin. Consistent with the transcriptional activation of p21(WAF1/Cip1) promoter by apicidin, apicidin treatment led to the translocation of PKCepsilon from cytosolic to particulate fraction, which was reversed by pretreatment with calphostin C, indicating the involvement of PKC in the transcriptional activation of p21(WAF1/Cip1) via Sp1 sites by apicidin. However, the PKC-mediated transcriptional activation of p21(WAF1/Cip1) by apicidin appears to be independent of the histone hyperacetylation, because apicidin-induced histone hyperacetylation was not affected by calphostin C. Furthermore, a PKC activator, phorbol 12,13-dibutyrate, alone induced the transcriptional activation of p21(WAF1/Cip1) promoter, p21(WAF1/Cip1) mRNA, and protein expression without induction of the histone hyperacetylation, suggesting that the transcriptional activation of p21(WAF1/Cip1) by apicidin might have been mediated by a mechanism other than chromatin remodeling through the histone hyperacetylation. Taken together, these results suggest that the PKC signaling pathway plays a pivotal role in the transcriptional activation of the p21(WAF1/Cip1) gene by apicidin.

[The changes of serum levels of interleukin-6 and interleukin-8 in pregnant women with systemic lupus erythematosus]

OBJECTIVE

To assess the changes of serum levels of interleukin-6(IL-6) and interleukin-8 (IL-8) in pregnant women with stationary phase systemic lupus erythematosus (SLE).

METHODS

Enzyme-linked immunosorbent assay (ELISA) was used to measure serum IL-6 and IL-8 from 14 pregnant women with stationary phase SLE (SLE group), 12 normal pregnant women (normal pregnant group) and 12 normal non-pregnant women (group normal non-pregnant). The later two groups are set as controls.

RESULTS

The IL-6, IL-8 levels in group SLE patients are (20.31 +/- 5.70) ng/L and (48.80 +/- 9.17) ng/L, significantly higher than those in normal pregnant group [IL-6, IL-8 levels are (8.40 +/- 2.49) ng/L and (21.15 +/- 5.21) ng/L, respectively, P < 0.01)] and normal non-pregnant group [IL-6, IL-8 levels are (6.14 +/- 0.86) ng/L and (17.71 +/- 4.43) ng/L, respectively, P < 0.01]. However, there's no significant difference between the normal pregnant group and normal non-pregnant group (P > 0.05).

CONCLUSION

Serum levels of IL-6, IL-8 may be helpful to monitor the progress of SLE during pregnancy.

Cultural value similarities and differences among Asian American ethnic groups

Using data on 570 Chinese, Filipino, Korean, and Japanese American college students from 3 previous studies (1 published [B. S. K. Kim, D. R. Atkinson, & P. H. Yang, 1999] and 2 unpublished [B. S. K. Kim, 1999; E. C. Wong, B. S. K. Kim, N. W. S. Zane, I. J. Kim, & J. S. Huang, 1999]), the authors subjected 22 items constituting 6 value dimensions of the Asian Values Scale (AVS; B. S. K. Kim et al., 1999) to the following structural equation modeling procedures: confirmatory factor analysis, factorial invariance analysis, and structured means analysis. The results of confirmatory factor analysis provided support for a hierarchical factor model when this model was compared with 2 competing models. The results of factorial invariance analysis indicated that the meanings of the factors within the hierarchical model were conceived similarly among the 4 Asian American ethnic groups. On the basis of these results, a structured means analysis was conducted, revealing similarities and differences between the ethnic groups' adherence to 6 cultural value dimensions. Implications regarding psychological services for these Asian Americans are discussed, and suggestions for future research are offered.

[An new filling material of hair for the application of plastic surgery]

OBJECTIVE

To investigate the possibility of hair as a filling material for reconstructive or cosmetic surgery.

METHODS

Sterilized pellets of hairs and silicone were selected and implanted subcutaneously in white rabbits. The clinical trial was carried out in 3 cases.

RESULTS

A thin fibrous capsule, with much few inflammatory cells, was formed around the implanted hair pellets in 3-4 months. The inflammatory cells disappeared in the 9th month. No implant rejection, granulomatous formation or hair degradation was showed.

CONCLUSION

Hair may be a valuable filling material for augmentation of the soft tissue.

Post-World War II uranium changes in dated Mont Blanc ice and snow

Recent controversies concerning the possibility of environmental contamination due to the use of uranium in classical weaponry have led us to realize that there is a lack of time series for this metal from environmental archives. We have therefore performed analysis of a dated 140 m-long ice/snow core that was drilled in 1994 at a cold high altitude site (4250 m) near the summit of Mont Blanc in the French-Italian Alps. Ultraclean analytical procedures were employed in our analyses. Uranium concentrations were determined by inductively coupled plasma sector field mass spectrometry. In ice dating from before the 1940s, uranium concentrations are found to have remained fairly constant and can be explained simply by a crustal contribution. For the post-World War II layers, on the other hand, the data show large excesses above crustal contributions. These uranium excesses are attributed to tropospheric transport of dust emitted during extensive mining and milling operations which took place in the GDR and to a smaller extent in France at that time. There is no enhancement in uranium concentrations in the ice layer in which fallout from the 1986 Chernobyl accident was previously identified from a gross beta activity vs depth profile.

ATP synthase motor components: proposal and animation of two dynamic models for stator function

Recent research indicates that ATP synthases (F(0)F(1)) contain two distinct nanomotors, one an electrochemically driven proton motor contained within F(0) that drives an ATP hydrolysis-driven motor (F(1)) in reverse during ATP synthesis. This is depicted in recent models as involving a series of events in which each of the three alphabeta pairs comprising F(1) is induced via a centrally rotating subunit (gamma) to undergo the sequential binding changes necessary to synthesize ATP (binding change mechanism). Stabilization of this rotary process (i.e., to minimize "wobble" of F(1)) is provided in current models by a peripheral stalk or "stator" that has recently been shown to extend from near the bottom of the ATP synthase molecule to the very top of F(1). Although quite elegant, these models envision the stator as fixed during ATP synthesis, i.e., bound to only a single alphabeta pair. This is despite the fact that the binding change mechanism views each alphabeta pair as going through the same sequential order of conformational changes which demonstrate a chemical equivalency among them. For this reason, we propose here two different dynamic models for stator function during ATP synthesis. Both models have been designed to maintain chemical equivalency among the three alphabeta pairs during ATP synthesis and both have been animated.

First Report and Partial Molecular Characterization of a New Begomovirus Associated with Pigeon Pea in Puerto Rico

Pigeon pea (Cajanus cajan (L.) Millsp.) is an important edible legume crop in Puerto Rico. In late fall 1997, symptoms of a golden mosaic virus were observed in a pigeon pea planting in the municipality of Villalba. The symptoms resembled those incited by the Rhynchosia mosaic virus, a whitefly-transmitted virus, in pigeon pea (1). Tests with the 3F7 antigeminivirus antibody from Agdia (Elkhart, IN) confirmed the presence of a begomovirus in these symptomatic pigeon peas. Extraction of DNA from dried symptomatic foliar tissue was accomplished by the methods described in Rojas et al. (2), and subsequent viral DNA amplification was accomplished with the coat protein (CP) gene polymerase chain reaction primer pair AV494-AC1048 (3). A 550-bp fragment was cloned and sequenced (GenBank Accession No. AY028308). For sequence analysis, the BLAST program at the National Institutes of Health was used. The first match was 91% with the CP gene sequence (Accession No. AF070924) of a begomovirus from Clitoria falcata from Puerto Rico. The next three matches were approximately 86% with a begomovirus (accession no. AF058024) from Macroptilium lathyroides from Puerto Rico, Dicliptera yellow mottle virus (Accession No. AF139168) from Florida, and Tobacco apical stunt virus (Accession No. AF076855) from Mexico. On the basis of sequence analysis of this conserved region of the CP gene, it is concluded that the virus described in this report is a new virus, and thus named Pigeon pea golden mosaic virus. The only sequence for a begomovirus from a Rhynchosia sp. in GenBank is Rhynchosia golden mosaic virus from Honduras (accession no. AF239671). On the basis of sequence comparisons, the virus from pigeon pea is not an isolate of the Honduran Rhynchosia golden mosaic virus. References: (1) J. Bird et al. 1975. Pages 3-25 in: Tropical Diseases of Legumes. J. Bird and K. Maramorosch, eds. Academic Press, NY. (2) M. R. Rojas et al. Plant Dis. 77:340, 1993. (3) S. D. Wyatt and J. K. Brown. Phytopathology. 86:1288, 1996.

Sample Size in Factor Analysis: The Role of Model Error

This article examines effects of sample size and other design features on correspondence between factors obtained from analysis of sample data and those present in the population from which the samples were drawn. We extend earlier work on this question by examining these phenomena in the situation in which the common factor model does not hold exactly in the population. We present a theoretical framework for representing such lack of fit and examine its implications in the population and sample. Based on this approach we hypothesize that lack of fit of the model in the population will not, on the average, influence recovery of population factors in analysis of sample data, regardless of degree of model error and regardless of sample size. Rather, such recovery will be affected only by phenomena related to sampling error which have been studied previously. These hypotheses are investigated and verified in two sampling studies, one using artificial data and one using empirical data.

Sorption and mobility of dithiopyr in golf course greens rooting medium

Sorption and mobility of dithiopyr in golf course greens rooting medium (RM) were studied. The sorption increased from 20 to 27 degrees C at 24 h after treatment (HAT) and reached equilibrium in 48 HAT at 20 degrees C. The sorption isotherms had Freundlich values (KF) of 1122, 27.44 to 35.16, and 0.053 to 0.168 for peat moss, the RM, and quartz sand, respectively, and solid to aqueous phase partition coefficients (Kd) of 470 to 1706 L/kg, 14.61 to 84.4 L/kg, and 0.07 to 0.29 L/kg for peat moss, RM, and quartz sand, respectively. Generally, higher dithiopyr concentration in the aqueous solution and the reduced pH of the solution corresponded to the higher Kd values. The average values for dispersion (D, cm2/min), retardation coefficient (R), beta, and omega parameters for solute transport in the RM lysimeter; obtained from CXTFIT curve fitting of Br- breakthrough curves; were 0.95, 1.01, 1, and 93.89, respectively. After elutriation by 18 L of aqueous KNO3 (10 mM), greater than 90% of the added dithiopyr remained in the top 10 cm of the RM lysimeter and no detectable dithiopyr was present at depths beyond 35 cm. The lysimeter effluent contained dithiopyr at concentrations less than 3.5 microg/L. The R value obtained from CXFIT curve fitting is 38.5. Results from both sorption and mobility experiments indicated that dithiopyr is quite immobile in golf course greens RM and has minimal potential for movement into surface water drainage or ground water.

Pattern analysis of sleep-deprived human EEG

Progress during the past decade in non-linear dynamics and instability theory has provided useful tools for understanding spatio-temporal pattern formation. Procedures which apply principle component analysis (using the Karhunen-Loeve decomposition technique) to the multichannel electroencephalograph (EEG) time series have been developed. This technique shows localized changes of cortical functioning; it identifies increases and decreases of the activity of localized cortical regions over time while the subject performs a simple task or test. It can be used to demonstrate the change in cortical dynamics in response to a continuous challenge. Using 16 EEG electrodes, the technique provides spatio-temporal information not obtained with power spectrum analysis, and includes the weighted information given with omega complexity. As an application, we performed a pattern analysis of sleep-deprived human EEG data in 20 healthy young men. Electroencephalograph recordings were performed on subjects for <2 min, with eyes closed after normal sleep and after 24 h of experimentally-induced sleep deprivation. The significant changes in the eigenvector components indicated the relative changes of local activity in the brain with progressive sleep deprivation. A sleep deprivation effect was observed, which was hemispherically correlated but with opposite directional dynamics. These changes were seen in the temporo-parietal regions bilaterally. The application of the technique showed that the simple test task was performed with a limited unilateral hemispheric involvement at baseline, but needed a much larger cortical participation with decreased frontal activity and increased coherence and bilateral hemispheric involvement. The calculations performed demonstrated that the same weighted changes as those obtained with omega complexity were shown, but the technique had the added advantage of showing the localized directional changes of the principle eigenvector at each studied electrode, pointing out the cortical localized region affected by the sleep deprivation and toward which direction the environmental challenge induced the spatial change. This methodology may allow the evaluation of changes in local dynamics in brain activity in normal and pathological conditions.

An evaluation of the changes in malocclusion index scores over a 25-year period

BACKGROUND

The measured values of specific traits of occlusion may be subject to significant change due to growth and maturation of the dentofacial structures. Some traits may show improvement while others may show deterioration. Rarely is there an opportunity to examine a sample of occlusions 25 years after the acquisition of the original set of records. This study examines the changes in traits of occlusion in a sample of 46 subjects who were originally examined between 1971-1973 and for whom records were again obtained in 1998.

METHODS

The 46 patients were a sub-group of a previously selected randomised school-based sample and study models obtained in 1971-1973 were still available. New models for each patient were obtained in 1998. Of the 46 subjects, only eight had received orthodontic treatment.

RESULTS

Assessments of the changes in specific traits were made using the methods proposed in the Harry L Draker, California Modification (HLD Cal Mod) index. This simple index was chosen because the main component traits were well defined and, when analysed separately, reflected changes with time. The total index score gave a broad indication of the global changes in the individual's occlusion. The five basic traits of the HLD index include overjet, overbite, openbite, mandibular protrusion and labio-lingual spread. Three additional traits (ectopic eruption, anterior crowding and posterior crossbite) are used in the HLD Cal Mod index. These traits provided a useful reflection of occlusal changes with time. Measurements were made with reference to specifications and the details outlined in the HLD Cal Mod protocol. The results revealed an increase in total index scores over time with a significant increase in lower labio-lingual spread associated with an increased score in anterior crowding. Overjet and overbite, however, displayed a significant decrease with time.

CONCLUSIONS

These findings are in keeping with previous studies and highlight the importance of time as a significant issue in the assessment of occlusion.

The natural killer T-cell ligand alpha-galactosylceramide prevents autoimmune diabetes in non-obese diabetic mice

Diabetes in non-obese diabetic (NOD) mice is mediated by pathogenic T-helper type 1 (Th1) cells that arise because of a deficiency in regulatory or suppressor T cells. V alpha 14-J alpha 15 natural killer T (NKT) cells recognize lipid antigens presented by the major histocompatibility complex class I-like protein CD1d (refs. 3,4). We have previously shown that in vivo activation of V alpha 14 NKT cells by alpha-galactosylceramide (alpha-GalCer) and CD1d potentiates Th2-mediated adaptive immune responses. Here we show that alpha-GalCer prevents development of diabetes in wild-type but not CD1d-deficient NOD mice. Disease prevention correlated with the ability of alpha-GalCer to suppress interferon-gamma but not interleukin-4 production by NKT cells, to increase serum immunoglobulin E levels, and to promote the generation of islet autoantigen-specific Th2 cells. Because alpha-GalCer recognition by NKT cells is conserved among mice and humans, these findings indicate that alpha-GalCer might be useful for therapeutic intervention in human diseases characterized by Th1-mediated pathology such as Type 1 diabetes.

The production and bioactivity of rainbow trout (Oncorhynchus mykiss) recombinant IL-1 beta

The predicted rainbow trout mature interleukin-1 beta (IL-1 beta) peptide has been produced as a recombinant protein in E. coli. The bioactivity of this molecule has been studied using trout head kidney cell preparations and a trout macrophage cell line (RTS11). Trout rIL-1 beta was shown to increase the expression level of IL-1 beta, cyclooxygenase (COX2) and MHC class II beta chain transcription, as determined by Northern blot analysis. Stimulatory doses of rIL-1 beta were typically > or =10 ng/ml. Induction of IL-1 beta expression occurred within 1h post-stimulation with trout rIL-1 beta and was maximal 3-6h post-stimulation. Trout rIL-1 beta was also able to increase murine D10.G4.1 cell proliferation and trout head kidney leukocyte phagocytic activity, in a dose-dependent manner. However, equivalent D10.G4.1 cell proliferation was induced with approximately 1000-fold lower doses of human rIL-1 beta. That LPS contamination did not contribute to the effects seen was confirmed by determining its concentration in the trout rIL-1 beta preparation, and demonstrating that the rIL-1 beta activity was inhibited by heating or pre-incubation with a polyclonal anti-trout rIL-1 beta antibody.

[A random study on taxol and concomitant radiotherapy vs sequential combined modality in treatment of advanced non-small cell lung cancer]

BACKGROUND

To evaluate the results of taxol and concomitant radiotherapy and those of sequential combined modality chemotherapy with taxol plus cisplatin ( DDP) and radiotherapy in treatment of locally advanced non small cell lung cancer ( NSCLC) .

METHODS

From January 1998 through August 1999, 36 patients ( 24 male, 12 female; 18 squamous cell carcinoma, 14 adenocarcinoma, 4 others; 24 initially treated, 12 retreated) with locally advanced NSCLC were enrolled in this study and were randomized into 2 groups. The median age of the patients was 58. The majority of patients had a performance status of 0 or 1. In concomitant group, the patients received radiation therapy at 2 Gy given on Monday to Friday of each week for 6 to 7 consecutive weeks. The total planned radiation dose was 60 to 65 Gy. At twenty-four hours before radiotherapy, taxol 40 mg / m² was administered on Sunday of each week for 6 consecutive weeks. In sequential group, the patients received induction chemotherapy with taxol 175 mg/ m² and cisplatin 100mg/ m² every 3 weeks for two cycles followed by conventional radiation therapy.

RESULTS

The overall response rate was 66. 7% ( 12/ 18) in concomitant group and 50%( 9/ 18) in sequential group. The local control rate was 83. 3%( 15/ 18) in concomitant group and 50% ( 9/ 18) in sequential group. The main toxicity in concomitant group was esophagitis ( 72. 2%, 13/ 18) . The hematological tox icity and other nonhematological toxicity were mild in concomitant group. The main toxicities in sequential group were leukocytopenia ( 94. 4% , 17/ 18; grade 3/ 4 in 7 patients) , nausea and vomiting ( 94. 4%, 17/ 18; grade 3/ 4 in 5 patients) , alopecia ( grade 3/ 4 in 8 patients) , neurotoxicity ( grade 1/ 2 in 14 patients) and nephrotoxicity ( grade 1/ 2 in 5 patients) . One year survival rate in concomitant group was 50% ( 9/ 18) and in sequential group was 44. 4% ( 8/ 18) . The median survival period was 12 months in concomitant group and 11 months in sequential group.

CONCLUSIONS

Weekly taxol and concomitant radiotherapy is as effective as sequential combined modality in patients with locally advanced NSCLC and concomitant chemoradiotherapy has higher local control rate and lower tox icity except for esophagitis.

Primary effusion lymphoma with herpesvirus 8 DNA in patients coinfected with HIV and hepatitis C virus: a report of 2 cases

The primary effusion lymphoma (PEL), commonly described in patients with AIDS, is a unique subset of diffuse large cell lymphoma in which the malignant lymphocytes proliferate exclusively in serous cavities. The cytologic, immunophenotypic, and molecular features of PEL are presented from findings of 2 patients coinfected with HIV and hepatitis C virus who presented with abdominal pain. Abdominal radiography in both patients displayed marked peritoneal effusions. Cytomorphologic examination of peritoneal fluid revealed a malignant lymphoma in both. Their immunophenotypic expression was CD30 (Ki-1) and epithelial membrane antigen. Molecular analysis demonstrated human herpesvirus 8 DNA in both patients and bcl-2 oncogene rearrangement within the major breakpoint region of t(14;18) chromosome translocation in Case B only. Clinical correlation supports the current concept that PEL represents a primary HIV/AIDS-related lymphoma in effusion. Cytomorphologic examination of body cavity fluid serves as a tool for the initial diagnosis of PEL.

Structure of the Ba-induced Si(111)- (3 x 2) reconstruction

The Ba/Si(111) surface, previously known as a 3 x 1 phase, is found to have a 3 x 2 periodicity and a semiconducting band gap. The substrate reconstructs into the honeycomb chain-channel (HCC) structure with Ba atoms in the channel, as in the alkali-metal-induced Si(111)-(3 x 1). However, the metal coverage is determined to be 1/6 monolayers, half the alkali-metal coverage. We propose that the structure and the metal coverage determined for the Ba adsorbate is universal for other alkaline-earth-metal adsorbates. With the alkali-metal-induced 3 x 1 case, our results lead to a rule that one donated electron per 3 x 1 surface unit is necessary to stabilize the HCC reconstruction of Si.

Functional Interaction of bZIP Proteins and the Large Subunit of Replication Factor C in Liver and Adipose Cells

The transcription factor CCAAT/enhancer-binding protein-alpha (C/EBPalpha) has a vital role in cell growth and differentiation. To delineate further a mechanism for C/EBPalpha-mediated differentiation, we screened C/EBPalpha-interacting proteins through far-Western screening. One of the strongest interactions was with RFC140, the large subunit of the replication factor C complex. C/EBPalpha specifically interacted with RFC140 from rat liver nuclear extract as determined by a combination of affinity chromatography and co-immunoprecipitation. Subsequent far-Western blotting showed that the bZIP domain of C/EBPalpha interacted with the DNA-binding region of RFC140. Overexpression of RFC140 in mammalian cells increased the transactivation activity of C/EBPalpha on both minimal and native promoters. Consistent with the enhanced transactivation, a complex of C/EBPalpha and RFC140 proteins with the cognate DNA element was detected in vitro. The specific interaction between C/EBPalpha and RFC140 was detected in the terminal differentiation of 3T3-L1 preadipocytes to adipocytes. The synergistic transcription effect of these two proteins increased the promoter activity and protein expression of peroxisome proliferator-activated receptor-gamma, which is a main regulator of adipocyte differentiation. Our results demonstrate that the specific transcription factor C/EBPalpha and the general DNA replication factor RFC140 interact functionally and physically. This observation highlights a unique mechanism by which the levels of the general replication factor can strongly modulate the functional activity of the specific transcription factor as a coactivator.

Antigen-induced translocation of PKC-theta to membrane rafts is required for T cell activation

Protein kinase C-theta (PKC-theta) is essential for mature T cell activation; however, the mechanism by which it is recruited to the TCR signaling machinery is unknown. Here we show that T cell stimulation by antibodies or peptide-major histocompatibility complex (MHC) induces translocation of PKC-theta to membrane lipid rafts, which localize to the immunological synapse. Raft translocation was mediated by the PKC-theta regulatory domain and required Lck but not ZAP-70. In addition, PKC-theta was associated with Lck in the rafts. An isolated PKC-straight theta catalytic fragment did not partition into rafts or activate the transcription factor NF-kappa B, although addition of a Lck-derived raft-localization sequence restored these functions. Thus, physiological T cell activation translocates PKC-theta to rafts, which localize to the T cell synapse; this PKC-theta translocation is important for its function.

Analysis of the amino terminus of maize branching enzyme II by polymerase chain reaction random mutagenesis

Maize endosperm branching enzyme II (mBEII) plays a pivotal role in determining the quality of starch by catalyzing the synthesis of the alpha-1,6-branch points. While the central (alpha/beta)8-barrel and the C-terminal domains of mBEII have been analyzed previously, the possible role of its amino terminus in catalysis is still poorly understood. Because the amino terminus of mBEII shares very little sequence homology with other amylolytic enzymes, the Met1-Gly276 region of mBEII was randomly mutagenized under error-prone PCR conditions. Subsequent screening by a heterologous complementation system, utilizing an Escherichia coli strain devoid of the endogenous glycogen branching enzyme (glgB-), led to the recovery of mBEII mutants with altered iodine-staining patterns and reduced branching enzyme activities. The NR-625 mutant enzyme, which lacks the N-terminal 39 residues of mBEII due to a frameshift mutation introduced during the random mutagenesis, retained more than 70% of the wild-type activity. The chain transfer pattern and substrate preference of the truncated enzyme were almost identical to those of the wild-type mBEII. It appears that the N-terminal 39 residues of mBEII are neither required for catalysis nor involved in chain transfer. On the other hand, the Gln-to-Arg substitution at position 270 of mBEII resulted in the loss of more than 90% of branching activity. The Gln270 of mBEII, located at the beginning of the (alpha/beta)8-barrel domain, may be required for maximum enzyme activity.

[A population-based surveillance system on birth defects and its application]

OBJECTIVE

To describe a unique surveillance system on birth defects in the People's Republic of China.

METHODS

The system was instituted in 1992 as a component for the evaluation on the effectiveness of a community intervention program using periconceptional folic acid supplementation to prevent neural tube defects and currently carries out surveys on a birth cohort of approximately 150 000 infants per year. Information was collected in the form of detailed written descriptions by local health care providers and photographs of affected infants. The system allowed for detection of birth defects at the local level with later definitive classification and coding; however, information was limited to those structural anomalies which were visible on physical examination.

RESULTS

This surveillance system on birth defects provides an extensive database of infants with major and minor external structural anomalies. From 1993 to 1996, more than one million births were monitored, with more than 10 000 birth defects and 30 000 photos submitted. Among them 5 000 were identified with major birth defects. Neural tube defects, oral clefts and extremity abnormalities were the first few defects with most cases. Data were used in birth defect surveillance reports and scientific papers.

CONCLUSIONS

This system can be utilized for studies on etiology, descriptive epidemiology, and identification of unusual trends which is unique with multiple advantages in the People's Republic of China.

Drosophila Hsc70-4 is critical for neurotransmitter exocytosis in vivo

Previous in vitro studies of cysteine-string protein (CSP) imply a potential role for the clathrin-uncoating ATPase Hsc70 in exocytosis. We show that hypomorphic mutations in Drosophila Hsc70-4 (Hsc4) impair nerve-evoked neurotransmitter release, but not synaptic vesicle recycling in vivo. The loss of release can be restored by increasing external or internal Ca(2+) and is caused by a reduced Ca(2+) sensitivity of exocytosis downstream of Ca(2+) entry. Hsc4 and CSP are likely to act in common pathways, as indicated by their in vitro protein interaction, the similar loss of evoked release in individual and double mutants, and genetic interactions causing a loss of release in trans-heterozygous hsc4-csp double mutants. We suggest that Hsc4 and CSP cooperatively augment the probability of release by increasing the Ca(2+) sensitivity of vesicle fusion.

Functional interaction of transcriptional coactivator ASC-2 and C/EBPalpha in granulocyte differentiation of HL-60 promyelocytic cell

HL-60 promyelocytic cells were treated with retinoic acid (RA) to stimulate granulocyte differentiation. CCAAT/enhancer binding protein alpha (C/EBPalpha) is known to be the molecular switch during early hematopoietic developmental events that direct cells to the granulocytic pathway. Here we show that the coactivator activating signal cointegrator-2 (ASC-2) plays an important role in differentiation of HL-60 cells into granulocytes by mediating C/EBPalpha-induced gene transcription. The differentiation inducer RA increased mRNA and protein expression of ASC-2. The protein-protein interaction of C/EBPalpha and ASC-2 was detected by coimmunoprecipitation during granulocyte differentiation. Subsequently, GST-pull-down assay revealed that the N-terminal transactivation domain of C/EBPalpha could interact with ASC-2. This functional interaction of ASC-2 with C/EBPalpha drove a synergistic enhancement of C/EBPalpha-dependent transactivation and overexpression of the N-terminal C/EBPalpha protein in HL-60 cells inhibited ASC-2 responsiveness for C/EBPalpha activity in granulocyte differentiation, indicating C/EBPalpha dependency of ASC-2 activity. Taken together, these results suggest that the differentiation-dependent expressed ASC-2 protein physically and functionally interacts with C/EBPalpha and increases its transactivation activity, regulating specific gene transcription for granulocyte differentiation.

Comparison of pupil perimetry and visual perimetry in normal eyes: decibel sensitivity and variability

PURPOSE

To compare the sensitivity and variability of pupil perimetry with visual perimetry at the same retinal locations in normal subjects.

METHODS

Pupil perimetry was performed on the right and left eyes of 10 normal subjects using a computerized infrared pupillometer equipped to present perimetric light stimuli and record pupil light reflexes. Eleven locations were tested at different intensities along the horizontal meridian of each eye, and the decibel sensitivity of the pupil light reflex was compared with the visual threshold at the same location.

RESULTS

The shape and height of the hill of vision (retinal sensitivity) was very similar between the right and left eyes of each individual using either pupil perimetry (R2 = 0.69) or standard threshold perimetry (R2 = 0.62) but was less similar between subjects. Comparisons between pupil and visual sensitivity revealed a lack of correlation at the same retinal location in normal eyes (R2 = 0.19).

CONCLUSIONS

The high intereye correlation for either pupil or visual sensitivity may provide an important tool for detecting focal or asymmetric visual field damage. Although the basic shape of the sensitivity profile of pupil and visual responses was similar under the conditions of testing, the two did not correlate well within each eye among the normal subjects. This highlights that similarities do exist in the sensitivity profile of the two pathways, but they do not seem to vary in the same proportion between normal individuals.

Characterization of publicly available SNPs in the Korean population

Single-nucleotide polymorphisms (SNPs) are the most abundant form of genetic variations and have a great potential for mapping studies of complex genetic traits. Currently a great deal of effort is invested in the identification of SNPs, and a large volume of data is already available through public databases (NCBI, NCI, WICGR, HGBASE). For an association mapping study, SNP allele frequencies in the population are critical. As an initial step toward construction of an SNP database of the Korean population, we have determined the allele frequencies of 300 cSNPs selected from the public database in 24 individuals. Among the tested markers, approximately 23% did not show polymorphism in the population. The results suggest that the ethnic and population based differences should be considered in the selection of SNPs for the study of complex diseases with association mapping methods.

RGD-Tachyplesin inhibits tumor growth

Tachyplesin is an antimicrobial peptide present in leukocytes of the horseshoe crab (Tachypleus tridentatus). In this study, a synthetic tachyplesin conjugated to the integrin homing domain RGD was tested for antitumor activity. The in vitro results showed that RGD-tachyplesin inhibited the proliferation of both cultured tumor and endothelial cells and reduced the colony formation of TSU prostate cancer cells. Staining with fluorescent probes of FITC-annexin V, JC-1, YO-PRO-1, and FITC-dextran indicated that RGD-tachyplesin could induce apoptosis in both tumor and endothelial cells. Western blotting showed that treatment of cells with RGD-tachyplesin could activate caspase 9, caspase 8, and caspase 3 and increase the expression of the Fas ligand, Fas-associated death domain, caspase 7, and caspase 6, suggesting that apoptotic molecules related to both mitochondrial and Fas-dependent pathways are involved in the induction of apoptosis. The in vivo studies indicated that the RGD-tachyplesin could inhibit the growth of tumors on the chorioallantoic membranes of chicken embryos and in syngenic mice.

Type D retrovirus Gag polyprotein interacts with the cytosolic chaperonin TRiC

The carboxy terminus-encoding portion of the gag gene of Mason-Pfizer monkey virus (M-PMV), the prototype immunosuppressive primate type D retrovirus, encodes a 36-amino-acid, proline-rich protein domain that, in the mature virion, becomes the p4 capsid protein. The p4 domain has no known role in M-PMV replication. We found that two mutants with premature termination codons that remove half or all of the p4 domain produced lower levels of stable Gag protein and of self-assembled capsids. Interestingly, yeast two-hybrid screening revealed that p4 specifically interacted with TCP-1gamma, a subunit of the chaperonin TRiC (TCP-1 ring complex). TRiC is a cytosolic chaperonin that is known to be involved in both folding and subunit assembly of a variety of cellular proteins. TCP-1gamma also associated with high specificity with the M-PMV pp24/16-p12 domain and human immunodeficiency virus p6. Moreover, in cells, Gag polyprotein associated with the TRiC chaperonin complex and this association depended on ATP hydrolysis. In the p4 truncation mutants, the Gag-TRiC association was significantly reduced. These results strongly suggest that cytosolic chaperonin TRiC is involved in Gag folding and/or capsid assembly. We propose that TRiC associates transiently with nascent M-PMV Gag molecules to assist in their folding. Consequently, properly folded Gag molecules carry out the intermolecular interactions involved in self-assembly of the immature capsid.

Analytical method development for 18 pesticides in house dust and settled residues using SEC, SPE, TMS methylation, and GC-MS

An analytical method is developed to analyze eighteen pesticides in carpet dust and also dust that has settled on surfaces in order to determine the potential exposure of children to pesticide residues. For nonacid pesticides, the extract after centrifugation and filtration is cleaned up using size-exclusion chromatography (SEC) and then analyzed by gas chromatography (GC) coupled with a mass spectrometer (MS). The best solvent for extraction is ethyl acetate-cyclohexane (3:1). The recoveries of spiked nonacid pesticides from 2 g of dust are between 72% and 110% with a variation between 4.2% and 25.6%, and the detection limit is 10 to 50 ng/g dust, depending on the pesticide. For acid pesticides, the dust is extracted with a saturated Ca(OH)2 solution, centrifuged, cleaned up by polyvinylbenzene/polystyrene-type solid-phase extraction cartridges, and methylated with trimethylsilyldiazomethane (TMS). Acid pesticides on filter paper samples are extracted with acidified acetone (3 mM H3PO4) and methylated with TMS. Methylation with TMS is fast and easy to perform. Methyl esters of the pesticides are completely separated and detected at low levels by GC-MS in the selective ion monitoring mode. The average recoveries of pesticides from 2 g of dust are between 81% and 104%. The average recoveries of pesticides spiked on filter paper are between 88% and 113%. A capillary column with a stationary phase of trifluoropropylmethyl polysiloxane gives the best separation and sensitivity for most pesticides on the GC-MS.

Adsorption of ferrous iron on the lepidocrocite surface

This study explored the ferrous iron adsorption capacity of three synthesized lepidocrocites as well as their morphology and surface area. Their morphologies were observed using scanning electron microscopy (SEM) and their surface areas were measured by BET isotherm techniques using nitrogen gas at the liquid nitrogen temperature. The adsorption capacities of the three distinctive lepidocrocites were measured and the data were processed by multiple regression technique to obtain the adsorption constants in the proposed model. The microphotographs of the lepidocrocites revealed that lepidocrocites could have an acicular shape as well as the shape of agglomerated flocs. The surface areas of the synthesized lepidocrocites in this study varied widely from 48.98 m2 g(-1) to 150.28 m2 g(-1). Adsorption capacities of three distinctive lepidocrocites for ferrous iron were investigated at four different pH levels. It was observed that there was no correlation between the BET surface area and adsorption capacity. The sites accessible to nitrogen gas might not be available to ferrous iron in water. An adsorption model based on the Freundlich equation was built to predict the effect of pH and the equilibrium concentration of ferrous iron in water. Multiple regression of data revealed that the amount of ferrous iron adsorbed on the unit weight of lepidocrocite was proportional to the 0.57 power of the ferrous iron concentration and inversely proportional to the 0.66 power of the hydrogen ion concentration.

Cloning and expression analysis of rainbow trout Oncorhynchus mykiss tumour necrosis factor-alpha

A rainbow trout (Oncorhynchus mykiss) gene for tumor necrosis factor (TNF) has been cloned and sequenced. The cDNA contains an open reading frame of 738 nucleotides that translate into a 246 amino-acid putative peptide, with a 5' untranslated region (UTR) of 140 bp and a 3' UTR of 506 bp. Two potential N-linked glycosylation sites exist in the translation. The genomic sequence measures 2007 bp and contains three introns that intercept four coding exons. Expression studies using RT-PCR have shown that the trout TNF gene is constitutively expressed in the gill and kidney of unstimulated fish. Trout TNF expression could be up-regulated by stimulation of isolated head kidney leucocytes with lipopolysaccharide (LPS). Similarly, stimulation of a trout macrophage cell line (RTS11) with LPS resulted in an increased transcript level, as did incubation with recombinant trout interleukin (IL)-1 beta. The optimal timing for induction of TNF expression in trout macrophages was determined using recombinant trout IL-1 beta, where a clear induction was apparent by 2 h and peaked at 4 h. Evidence that this TNF gene is equivalent to mammalian TNF-alpha is discussed.

Purification and characterization of protein methylase II from Helicobacter pylori

Protein methylase II (AdoMet:protein-carboxyl O-methyltransferase, EC 2.1.1.24) was identified and purified 115-fold from Helicobacter pylori through Q-Sepharose ion exchange column, AdoHcy-Sepharose 4B column, and Superdex 200 HR column chromatography using FPLC. The purified preparation showed two protein bands of about 78 kDa and 29 kDa molecular mass on SDS-PAGE. On non-denaturing gel electrophoresis, the enzyme migrated as a single band with a molecular mass of 410 kDa. In addition, MALDI-TOF-MS analysis and Superdex 200 HR column chromatography of the purified enzyme showed a major mass signal with molecular mass values of 425 kDa and 430 kDa, respectively. Therefore, the above results led us to suggest that protein methylase II purified from H. pylori is composed of four heterodimers with 425 kDa (4x(78+29)=428 kDa). This magnitude of molecular mass is unusual for protein methylases II so far reported. The enzyme has an optimal pH of 6.0, a K(m) value of 5.0x10(-6) M for S-adenosyl-L-methionine and a V(max) of 205 pmol methyl-(14)C transferred min(-1) mg(-1) protein.

High yield expression and single step purification of human thionein/metallothionein

Human metallothionein (MT), isoform 2, was expressed in Escherichia coli as an intein (protein splicing element) fusion protein in the absence of added metals and purified by intein-mediated purification with an affinity chitin-binding tag (IMPACT system). This procedure constitutes a novel and simple strategy to prepare thionein (T), the metal-free form, or MT when reconstituting T with metals in vitro. The yield was 8 mg of T or 6 mg of pure Cd(7)- or Zn(7)-MT from a 1-L culture, significantly higher than yields from any other expression system. Purified recombinant protein is indistinguishable from the native protein on the basis of its metal-binding ability, titration of its sulfhydryls, and UV and CD spectra. The MALDI-TOF mass spectrum is consistent with that of T with a free N-terminus.

Long-term results of eyes with penetrating keratoplasty and glaucoma drainage tube implant

PURPOSE

To present long-term results of eyes with penetrating keratoplasty (PK) and glaucoma tube implant.

DESIGN

Retrospective, noncomparative, interventional case series.

PARTICIPANTS

We retrospectively reviewed medical records of all patients who underwent both PK and glaucoma tube implant (Baerveldt or Ahmed) at the University of Iowa between July of 1988 and December of 1997 (55 eyes).

METHODS

Success of the tube implant or PK was evaluated using Kaplan-Meier survival analysis. Association of relevant clinical factors with glaucoma or corneal graft outcome was evaluated using log-rank test or Cox proportional hazard regression analysis. The factors evaluated were glaucoma and cornea diagnoses; prior, simultaneous, and subsequent surgeries; type of tube implant; relative timing of surgeries; and postsurgical complications.

MAIN OUTCOME MEASURES

Glaucoma outcome was assessed by postoperative intraocular pressure (IOP), number of medications, and need for further glaucoma surgery. Corneal outcome was assessed by graft rejection, failure, and Snellen visual acuity. Surgical procedures before and during the study period, and their complications were evaluated.

RESULTS

The mean preoperative intraocular pressure was 29.8 mmHg with an average of 2.9 medications. At last postoperative follow-up, the mean IOP decreased to 14.3 mmHg with 0.7 medication. The tube implant successfully controlled glaucoma in 45 eyes (82%) at 3 years. More severe postsurgical complications were associated with greater glaucoma failure. Graft rejection occurred in 17 eyes, and 7 of these progressed to failure. Nonimmunologic graft failure occurred in an additional 17 eyes (31%). The remaining 31 eyes (56%) had a clear graft. The corneal grafts remained clear in 70% and 55% of eyes at 2 and 3 years, respectively. Corneal graft failure was associated with glaucoma and cornea diagnoses groups, type of tube implant, and relative timing of the two surgeries. Complications occurred in 23 eyes (42%), and 10 of these were serious.

CONCLUSIONS

A drainage tube implant can successfully control glaucoma in a majority (82%) of keratoplasty eyes at 3 years. However, the success of corneal grafts is low (55%) at 3 years. Postsurgical complications are not uncommon and are associated with poor glaucoma outcome. Other clinical factors are associated with poor graft outcome.

Synergistic antidiabetic activities of zinc, cyclo (his-pro), and arachidonic acid

Previous studies have already shown that prostate extract (PE) has antidiabetic activity when given to animals and humans. In this study, we explore whether this antidiabetic activity is related to the high concentrations of zinc, cyclo (his-pro) (CHP), and the prostaglandin precursor, arachidonic acid (AA), in prostate tissue. When streptozotocin-induced diabetic rats were given drinking water containing 10 mg/L zinc and 100 mg/L PE for 3 weeks, fasting blood glucose levels and glucose clearance rates, but not plasma insulin levels, were significantly lower than at pretreatment. In subsequent experiments, blood glucose levels in rats given PE for 3 weeks were significantly lower than in rats given distilled water or 10 mg/L zinc alone. However, in rats given 100 mg/L CHP with zinc, blood glucose levels were also lower than in rats given PE alone. Time-course studies in diabetic rats given drinking water containing 20 mg/L Zn, 20 mg/L L-histidine, and 10 mg/L CHP showed that blood glucose levels dropped 209 +/- 53 mg/dL in 1 day and stayed low for 2 weeks. When CHP was replaced with 100 mg AA/L, blood glucose levels dropped 230 +/- 64 mg/dL in 5 days, but returned to the original values 11 days later. Growth rate improved and water consumption decreased significantly in CHP- and AA-treated diabetic rats. High intake of L-histidine and testosterone increased blood glucose concentrations in diabetic rats. To determine optimal dosages of CHP and AA, we gave rats drinking water containing 10 mg/L Zn and 0.5 mg/L L-histidine with various concentrations of CHP or AA. The most effective doses for reducing blood glucose levels were 0.32 mg CHP/kg/day and 11 mg AA/kg/day. These data suggest that the active antidiabetic ingredients in the PE are CHP, zinc, and AA or its precursors.

RbcS suppressor mutations improve the thermal stability and CO2/O2 specificity of rbcL- mutant ribulose-1,5-bisphosphate carboxylase/oxygenase

In the green alga Chlamydomonas reinhardtii, a Leu(290)-to-Phe (L290F) substitution in the large subunit of ribulose-1, 5-bisphosphate carboxylase/oxygenase (Rubisco), which is coded by the chloroplast rbcL gene, was previously found to be suppressed by second-site Ala(222)-to-Thr and Val(262)-to-Leu substitutions. These substitutions complement the photosynthesis deficiency of the L290F mutant by restoring the decreased thermal stability, catalytic efficiency, and CO(2)/O(2) specificity of the mutant enzyme back to wild-type values. Because residues 222, 262, and 290 interact with the loop between beta strands A and B of the Rubisco small subunit, which is coded by RbcS1 and RbcS2 nuclear genes, it seemed possible that substitutions in this loop might also suppress L290F. A mutation in a nuclear gene, Rbc-1, was previously found to suppress the biochemical defects of the L290F enzyme at a posttranslational step, but the nature of this gene and its product remains unknown. In the present study, three nuclear-gene suppressors were found to be linked to each other but not to the Rbc-1 locus. DNA sequencing revealed that the RbcS2 genes of these suppressor strains have mutations that cause either Asn(54)-to-Ser or Ala(57)-to-Val substitutions in the small-subunit betaA/betaB loop. When present in otherwise wild-type cells, with or without the resident RbcS1 gene, the mutant small subunits improve the thermal stability of wild-type Rubisco. These results indicate that the betaA/betaB loop, which is unique to eukaryotic Rubisco, contributes to holoenzyme thermal stability, catalytic efficiency, and CO(2)/O(2) specificity. The small subunit may be a fruitful target for engineering improved Rubisco.

Validity of measures of cognitive processes and general ability for learning and performance on highly complex computerized tutors: is the g factor of intelligence even more general?

Theoretical arguments and analyses from 2 studies provide compelling evidence that computerized measures of information-processing skills and abilities are highly useful supplements to more traditional, paper-based measures of general mental ability for predicting individuals' capacity to learn from and perform on highly challenging, multifaceted tutors. These tutors were designed to emulate learning and performance in complex, real-world settings. Hierarchical confirmatory factor analysis provided evidence that a general, higher order factor model with general ability at the apex could quite adequately and singularly account for the individual-differences data, both traditional and cognitive-process measures. Results are interpreted in light of the utility and generality of human cognitive abilities.

Apicidin, a histone deacetylase inhibitor, inhibits proliferation of tumor cells via induction of p21WAF1/Cip1 and gelsolin

Apicidin [cyclo(N-O-methyl-L-tryptophanyl-L-isoleucinyl-D-pipecolinyl -L-2-amino-8-oxodecanoyl)] is a fungal metabolite shown to exhibit antiparasitic activity by the inhibition of histone deacetylase (HDAC). In this study, we evaluated apicidin as a potential antiproliferative agent. Apicidin showed a broad spectrum of antiproliferative activity against various cancer cell lines, although with differential sensitivity. The antiproliferative activity of apicidin on HeLa cells was accompanied by morphological changes, cell cycle arrest at G1 phase, and accumulation of hyperacetylated histone H4 in vivo as well as inhibition of partially purified HDAC in vitro. In addition, apicidin induced selective changes in the expression of p21WAF1/Cip1 and gelsolin, which control the cell cycle and cell morphology, respectively. Consistent with increased induction of p21WAF1/Cip1, phosphorylation of Rb protein was markedly decreased, indicating the inhibition of cyclin-dependent kinases, which became bound to p21WAF1/Cip1. The effects of apicidin on cell morphology, expression of gelsolin, and HDAC1 activity in vivo and in vitro appeared to be irreversible, because withdrawal of apicidin did not reverse those effects, whereas the induction of p21WAF1/Cip1 by apicidin was reversible. Taken together, the results suggest that induction of histone hyperacetylation by apicidin is responsible for the antiproliferative activity through selective induction of genes that play important roles in the cell cycle and cell morphology.

Activity-wheel running blunts suppression of splenic natural killer cell cytotoxicity after sympathectomy and footshock

We used chemical sympathectomy by 6-hydroxydopamine (6-OHDA) to examine whether adaptation by the sympathetic nervous system (SNS) is a plausible explanation for our prior finding that activity-wheel running blunts the suppression of splenic natural killer cell cytotoxicity after footshock. Male Fischer rats were assigned to treatments using a group (activity wheel vs. sedentary)x treatment (6-OHDA vs. saline)x condition (footshock vs. no shock) design. After 5-6 weeks, rats were injected i.p. with saline or with 40, 80, and 80 mg/kg 6-OHDA on pre experimental days -5, -3, and -1. Half the rats received 6 min of random footshock during a 40-min period. Cytotoxicity was determined by standard 4-h 51Cr release assay. Sympathectomy reduced splenic [NE] by 72%. After 6-OHDA injection and footshock, percent lysis was 33% lower in sedentary rats compared with activity-wheel runners and home-cage controls, p=0.048. The results suggest that activity-wheel running leads to adaptations that offset an altered SNS modulation of splenic NK cell cytotoxicity in response to footshock.

Enhancement of paclitaxel production by temperature shift in suspension culture of Taxus chinensis

Effect of temperature shift during culture period on cell growth and paclitaxel was investigated to optimize paclitaxel production in suspension culture of Taxus chinensis. Cell growth showed the optimum at 24 degrees C while paclitaxel synthesis showed the maximum at 29 degrees C. To minimize the inhibitory effect of higher temperature on cell growth, temperature was shifted after a certain period of culture time at 24 degrees C. Paclitaxel synthesis in plant cell culture increased dramatically during day 14 to day 21 regardless of treatment, reaching the maximum production of 137.5 mg paclitaxel/L. When the temperature was maintained at 29 degrees C after day 21, the specific productivity of paclitaxel was sustained for prolonged period of 42 days. The possible relationship between temperature and paclitaxel synthetic pathway was also suggested.

Mitochondrial F(0)F(1) ATP synthase. Subunit regions on the F1 motor shielded by F(0), Functional significance, and evidence for an involvement of the unique F(0) subunit F(6)

Studies reported here were undertaken to gain greater molecular insight into the complex structure of mitochondrial ATP synthase (F(0)F(1)) and its relationship to the enzyme's function and motor-related properties. Significantly, these studies, which employed N-terminal sequence, mass spectral, proteolytic, immunological, and functional analyses, led to the following novel findings. First, at the top of F(1) within F(0)F(1), all six N-terminal regions derived from alpha + beta subunits are shielded, indicating that one or more F(0) subunits forms a "cap." Second, at the bottom of F(1) within F(0)F(1), the N-terminal region of the single delta subunit and the C-terminal regions of all three alpha subunits are shielded also by F(0). Third, and in contrast, part of the gamma subunit located at the bottom of F(1) is already shielded in F(1), indicating that there is a preferential propensity for interaction with other F(1) subunits, most likely delta and epsilon. Fourth, and consistent with the first two conclusions above that specific regions at the top and bottom of F(1) are shielded by F(0), further proteolytic shaving of alpha and beta subunits at these locations eliminates the capacity of F(1) to couple a proton gradient to ATP synthesis. Finally, evidence was obtained that the F(0) subunit called "F(6)," unique to animal ATP synthases, is involved in shielding F(1). The significance of the studies reported here, in relation to current views about ATP synthase structure and function in animal mitochondria, is discussed.

CD8+ T cells rapidly acquire NK1.1 and NK cell-associated molecules upon stimulation in vitro and in vivo

NKT cells express both NK cell-associated markers and TCR. Classically, these NK1.1+TCRalphabeta+ cells have been described as being either CD4+CD8- or CD4-CD8-. Most NKT cells interact with the nonclassical MHC class I molecule CD1 through a largely invariant Valpha14-Jalpha281 TCR chain in conjunction with either a Vbeta2, -7, or -8 TCR chain. In the present study, we describe the presence of significant numbers of NK1.1+TCRalphabeta+ cells within lymphokine-activated killer cell cultures from wild-type C57BL/6, CD1d1-/-, and Jalpha281-/- mice that lack classical NKT cells. Unlike classical NKT cells, 50-60% of these NK1.1+TCRalphabeta+ cells express CD8 and have a diverse TCR Vbeta repertoire. Purified NK1.1-CD8alpha+ T cells from the spleens of B6 mice, upon stimulation with IL-2, IL-4, or IL-15 in vitro, rapidly acquire surface expression of NK1.1. Many NK1.1+CD8+ T cells had also acquired expression of Ly-49 receptors and other NK cell-associated molecules. The acquisition of NK1.1 expression on CD8+ T cells was a particular property of the IL-2Rbeta+ subpopulation of the CD8+ T cells. Efficient NK1.1 expression on CD8+ T cells required Lck but not Fyn. The induction of NK1.1 on CD8+ T cells was not just an in vitro phenomenon as we observed a 5-fold increase of NK1.1+CD8+ T cells in the lungs of influenza virus-infected mice. These data suggest that CD8+ T cells can acquire NK1.1 and other NK cell-associated molecules upon appropriate stimulation in vitro and in vivo.

Natural killer cells determine the outcome of B cell-mediated autoimmunity

Natural killer (NK) cells can affect the outcome of adaptive immune responses. NK cells, but not NK1.1+T cells, were found to participate in the development of myasthenia gravis (a T cell-dependent, B cell- and antibody-mediated autoimmune disease) in C57BL/6 mice. The requirement for NK cells was reflected by the lack of a type I helper T cell response and antibodies to the acetylcholine receptor in both NK1.1+ cell-depleted and NK cell-deficient IL-18-/- mice. These findings establish a previously unrecognized link between NK cells and autoreactive T and B cells.