Chemical compositions of fine particulate organic matter emitted from Chinese cooking

Food cooking can be a significant source of atmospheric particulate organic matter. In this study, the chemical composition of particulate organic matter (POM) in PM2.5 emitted from four different Chinese cooking styles were examined by gas chromotography-mass spectrometry (GC-MS). The identified species are consistent in the emissions from different Chinese cooking styles and the quantified compounds account for 5-10% of total POM in PM2.5. The dominant homologue is fatty acids, constituting 73-85% of the quantified compounds. The pattern of n-alkanes and the presence of beta-sitosterol and levoglucosan indicate that vegetables are consumed during Chinese cooking operations. Furthermore, the emissions of different compounds are impacted significantly by the cooking ingredients. The candidates of organic tracers used to describe and distinguish emissions from Chinese cooking in Guangzhou are tetradecanoic acid, hexadecanoic acid, octadecanoic acid, oleic acid, levoglucosan, mannosan, galactosan, nonanal, and lactones. During the sampling period, the relative contribution of Chinese cooking to the mass concentration of atmospheric hexadecanoic acid should be less than 1.3% in Guangzhou.

Aerosols: Connection between regional climate change and air quality (IUPAC Technical Report)

Aerosols play an important role in all problems connected with air pollution, ranging from very local effects and human health problems to regional problems such as acid deposition and eutrophication up to continental and global questions such as stratospheric ozone loss and climatic change. In this report, an explanation of these effects is given and an assessment is made for parts of China, based on the aerosol data given by Zhang et al. elsewhere in this volume. (Pure Appl. Chem. 76(6), 1227-1239, 2004)

Epidemiological research has made clear that aerosols are a cause of enhanced mortality due to cardiopulmonary diseases (heart and lung diseases). Based on the same mortality as found in Europe and on linear extrapolation (with large uncertainties; no sufficient data are available to make better estimates), an excess mortality of 5000 to 10 000 due to acute effects and 20 000 to 50 000 due to chronic effects per year could be expected for a city like Beijing with a population of 14.5 million. A major cause of these uncertainties is problems in the determination of semivolatile compounds and elemental or black carbon in aerosols.

Aerosols have a strong impact on the radiative balance of the earth, in a direct way by reflecting solar light as well as in an indirect way by cloud formation leading to clouds with higher albedo, which reflect sunlight better. The total direct effect, backscatter of sunlight, including backscatter from nitrates and organic compounds, is estimated to be approximately 2 to 3 W m–2 for Western Europe, while the indirect effect is approximately 0 to –6 W m–2. Soot absorbs incoming solar radiation and heats the atmosphere. This process contributes 0.1 to 0.2 W m–2 on a global scale.

If PM-2.5 levels are compared with Europe, a direct effect of approximately –4 to –10 W m–2 would be plausible for China, black carbon could contribute probably about 0.5 to 2 W m–2, and the indirect effect could be about 0 to –6 W m–2. These effects could cause a net cooling over China (and over many developing countries in the same position) of about –4 to –15 W m–2. This estimate is obviously based on many assumptions and hence is quite uncertain.

One must be aware that measures reducing local aerosol concentrations will have a large impact on the radiative balance and could, over a few decades, have potentially at least the same impact as the build-up of greenhouse gases since the beginning of the Industrial Revolution.

The influence of geometry and draught shields on the performance of passive samplers

Passive samplers provide an excellent opportunity to perform indicative measurements or establish a dense network of measuring sites. A drawback compared with conventional active measuring methods is the larger spread of results. This variation can, to a large extent, be attributed to the influence of temperature, sampler geometry and wind on sampling results. A proper design of sampler geometry and optimum choice of draught shield can reduce the influence of wind velocity on a badge type sampler to less than 10%. Wire mesh screens prove to be inadequate in damping turbulence. Filters give good results. Attention should be paid to the size and isolation value of the walls of the sampler to prevent thermal updrafts occurring within the sampler. Tube type samplers are less influenced by wind, provided that turbulence is prevented from influencing diffusion within the sampler.

Local periocular vaccination protects against eye disease more effectively than systemic vaccination following primary ocular herpes simplex virus infection in rabbits

Vaccination of experimental animals can provide efficient protection against ocular herpes simplex virus type 1 (HSV-1) challenge. Although it is suspected that local immune responses are important in protection against ocular HSV-1 infection, no definitive studies have been done to determine if local ocular vaccination would produce more efficacious protection against HSV-1 ocular challenge than systemic vaccination. To address this question, we vaccinated groups of rabbits either systemically or periocularly with recombinant HSV-2 glycoproteins B (gB2) and D (gD2) in MF59 emulsion or with live KOS (a nonneurovirulent strain of HSV-1). Three weeks after the final vaccination, all eyes were challenged with McKrae (a virulent, eye disease-producing strain of HSV-1). Systemic vaccination with either HSV-1 KOS or gB2/gD2 in MF59 did not provide significant protection against any of the four eye disease parameters measured (conjunctivitis, iritis, epithelial keratitis, and corneal clouding). In contrast, periocular vaccination with gB2/gD2 in MF59 provided significant protection against conjunctivitis and iritis, while ocular vaccination with live HSV-1 KOS provided significant protection against all four parameters. Thus, local ocular vaccination provided better protection than systemic vaccination against eye disease following ocular HSV-1 infection. Since local vaccination should produce a stronger local immune response than systemic vaccination, these results suggest that the local ocular immune response is very important in protecting against eye disease due to primary HSV-1 infection. Thus, for clinical protection against primary HSV-1-induced corneal disease, a local ocular vaccine may prove more effective than systemic vaccination.

The importance of MHC-I and MHC-II responses in vaccine efficacy against lethal herpes simplex virus type 1 challenge

To investigate the importance of major histocompatability complex (MHC) class I- and MHC class II-dependent immune responses in herpes simplex virus-1 (HSV-1) vaccine efficacy, groups of beta 2% (MHC I-) and Ab% (MHC II-) mice were inoculated with various vaccines, and then challenged intraperitoneally with HSV-1. Following vaccination with either live avirulent HSV-1, expressed HSV-1 glycoprotein D (gD), or a mixture of seven expressed HSV-1 glycoproteins (7gPs), Ab% (MHC-II-) mice developed no enzyme-linked immunosorbent assay (ELISA) or neutralizing antibody titres. In contrast, significant ELISA and neutralizing antibody titres were induced in beta 2m% (MHC-I-) mice by all three vaccines. The neutralizing antibody titres were similar for all three vaccines, but were only approximately 1/4 to 1/3 of that developed in C57BL/6 (parental) mice vaccinated with the same antigens. All three vaccines protected 100% of the wild-type C57BL/6 mice against lethal challenge with 2 x 10(7) plaque-forming units (PFU) of HSV-1. The live virus vaccine and the 7gPs vaccine also protected 80% of the beta 2m% mice against the same lethal HSV-1 challenge dose. In contrast, in Abo/o mice, none of the vaccines provided significant protection against the same lethal challenge dose of HSV-1. However, at a lower challenge dose of 2 x 10(6) PFU, all three vaccines protected 70-80% of the vaccinated Ab% mice (compared to only 10% survival in mock vaccinated controls). Thus, vaccination provided some protection against lethal HSV-1 challenge in both beta 2m% and Ab% mice; however, the protection was less than that seen in the parental C57BL/6 mice. In addition, Ab% mice were less well protected by vaccination than were beta 2m% mice. Our results suggest that (1) both MHC-I and MHC-II are involved in vaccine efficacy against HSV-1 challenge; (2) both types of responses must be present for maximum vaccine efficacy: and (3) the MHC-II-dependent immune response appeared to be more important than the MHC-I-dependent immune response for vaccine efficacy against HSV-I challenge.

Nonneutralizing antibody against the glycoprotein K of herpes simplex virus type-1 exacerbates herpes simplex virus type-1-induced corneal scarring in various virus-mouse strain combinations

PURPOSE

To determine whether the exacerbation of herpes simplex virus type-1 (HSV-1) induced corneal scarring that the authors reported previously in HSV-1 glycoprotein K (gK) vaccinated BALB/c mice challenged with HSV-1 strain McKrae was a general phenomenon independent of virus and mouse strains. To determine the gK-induced immune response leading to exacerbation of HSV-1-induced corneal scarring.

METHODS

BALB/c or C57BL/6 mice were vaccinated with gK, ocularly challenged with HSV-1 strain KOS or McKrae, and the relative amount of corneal scarring determined 28 days after challenge. The T cells, total serum, or purified immunoglobulin G (IgG) isolated from gK-vaccinated mice was transferred individually to naive mice, and the affects on corneal scarring after HSV-1 challenge were determined.

RESULTS

The KOS challenge of gK-vaccinated BALB/c mice resulted in significant corneal scarring (P = 0.0003), despite the fact that KOS normally produces no corneal scarring. McKrae challenge of gK-vaccinated C57BL/6 mice resulted in significant corneal scarring (P < 0.0001), despite the fact that C57BL/6 mice are normally refractory to HSV-1-induced corneal scarring. Passive transfer of total anti-gK mouse sera or purified anti-gK mouse IgG, but not adoptive transfer of total anti-gK T-cells to naive mice, resulted in exacerbation of corneal scarring after HSV-1 challenge (P < 0.0001). Mice defective for T-cell-dependent antibody production were not susceptible to exacerbation of HSV-1-induced corneal scarring by gK vaccination (P < 0.0001).

CONCLUSIONS

The ability of gK vaccination to exacerbate HSV-1-induced corneal scarring was not mouse strain or HSV-1 strain specific. The gK-induced exacerbation of corneal scarring was related to anti-gK IgG. How anti-gK IgG exacerbated HSV-1 induced corneal scarring remains to be determined.

Vaccination of mice with herpes simplex virus type 1 glycoprotein D DNA produces low levels of protection against lethal HSV-1 challenge

The herpes simplex virus type 1 (HSV-1) glycoprotein D (gD) gene was inserted into vectors pSVL or pRc/CMV under control of the SV40 late promoter or the human cytomegalovirus major immediate-early promoter, respectively. Intramuscular injection of mice with these gD-containing plasmids appeared to induce low levels of serum anti-gD antibody, as judged by the appearance of low levels of anti-HSV-1-neutralizing antibody and anti-gD ELISA responses in the serum of gD-DNA-vaccinated mice. As previously reported in other virus systems, vaccination with vector DNA also induced ELISA and neutralizing antibody titers. However, these titers were lower than those induced by the gD-containing plasmids. The ELISA and neutralization titers induced by the vectors appeared to be non-specific rather than directed at specific HSV-1 proteins, since serum from mice vaccinated with plasmid-gD immunoprecipitated significant amounts of gD from extracts of HSV-1-infected cells, while serum from mice vaccinated with vectors was unable to immunoprecipitate gD or any other obvious HSV-1 proteins. Neither pSVL-gD nor pRc/CMV-gD induced detectable lymphocyte proliferative or CTL responses. Vaccination with pSVL-gD provided a significant (P = 0.04, Fisher's exact test), but low level of protection against lethal challenge with HSV-1. Vaccination with pRc/CMV-gD also appeared to provide a low level of protection against challenge, that was statistically significance at the 10% level (P = 0.054, Fisher's exact test). Reports from numerous laboratories (including ours) have shown that vaccination with recombinantly expressed gD can provide very high levels of protection against HSV-1 lethal challenge. Thus, the results reported here suggest that vaccination with HSV-1 gD-DNA is not yet a useful alternative to a gD subunit vaccine.

Expression and characterization of baculovirus expressed herpes simplex virus type 1 glycoprotein L

We have constructed a recombinant baculovirus expressing high levels of the herpes simplex virus type 1 (HSV-1) glycoprotein L (gL) in Sf9 cells. Sf9 cells infected with this recombinant virus synthesized three polypeptides of 26-27 kDa 28 kDa, and 31 kDa. The 28 and 31 kDa species were sensitive to tunicamycin and N-glycosidase F (PNGase F) treatment, suggesting that they were glycosylated. As shown by both indirect immunofluorescence and Western blot analysis, using polyclonal antibodies to synthetic gL peptides indicated that the baculovirus expressed gL was abundant on the surface of baculovirus gL infected Sf9 cells. A small fraction of the 31 kDa polypeptide was secreted into the extracellular medium as judged by Western blot analysis. The secreted form of gL was completely resistant to Endoglycosidase H (Endo-H), while the membrane associated form of gL was only partially resistant to Endo-H treatment, suggesting that the secreted gL represented a subpopulation of the membrane bound gL. Mice vaccinated with baculovirus expressed gL produced serum antibodies that reacted with authentic HSV-1 gL. However, these mice produced no HSV-1 neutralizing antibody (titer < 1:10) and they were not protected from lethal intraperitoneal or lethal ocular challenge with HSV-1. Thus, when used as a vaccine in the mouse model, gL, similar to our findings with HSV-1 gH, but unlike our results with the other 6 HSV-1 glycoproteins that we have expressed in this baculovirus system, did not provide any protection against HSV-1 challenge.

Vaccine therapy for ocular herpes simplex virus (HSV) infection: periocular vaccination reduces spontaneous ocular HSV type 1 shedding in latently infected rabbits

Periocular vaccination of rabbits with preexisting herpes simplex virus type 1 (HSV-1) latent infection with recombinant HSV-2 glycoproteins B and D (gB2 and gD2) plus adjuvant significantly reduced ocular viral shedding. Rabbits were infected in both eyes with HSV-1 strain McKrae. Following HSV-1 infection and the establishment of latency (28 days postinfection), rabbits were given a periocular subconjunctival vaccination three times at 3-week intervals. Beginning 3 weeks after the final vaccination, tear films were collected daily and cultured to detect the presence of HSV-1 and determine the spontaneous HSV-1 ocular shedding rates. Periocular vaccination increased the mean HSV-1 serum neutralizing antibody titer to fivefold above that seen in mock-vaccinated latently infected rabbits. gB enzyme-linked immunosorbent assay (ELISA) antibody titers were increased approximately 8-fold, and gD ELISA antibody titers were increased 60-fold. These increases were all statistically significant (P < 0.0001). In two independent experiments, vaccination reduced the spontaneous shedding rate by approximately 2.5-fold (P < 0.0004). In addition, the percentage of eyes that never shed virus during the 6 week postvaccination test period increased threefold (20% in controls versus 60% in vaccinated animals; P < 0.007). These results show that spontaneous ocular shedding of HSV-1 in latently infected rabbits can be significantly reduced by local periocular vaccination. This is the first report in any animal model of a successful therapeutic vaccine against recurrent HSV-1 ocular shedding. These results support the concept that development of a therapeutic vaccine for ocular HSV-1 recurrence in humans is possible.

Expression of seven herpes simplex virus type 1 glycoproteins (gB, gC, gD, gE, gG, gH, and gI): comparative protection against lethal challenge in mice

We have constructed recombinant baculoviruses individually expressing seven of the herpes simplex virus type 1 (HSV-1) glycoproteins (gB, gC, gD, gE, gG, gH, and gI). Vaccination of mice with gB, gC, gD, gE, or gI resulted in production of high neutralizing antibody titers to HSV-1 and protection against intraperitoneal and ocular challenge with lethal doses of HSV-1. This protection was statistically significant and similar to the protection provided by vaccination with live nonvirulent HSV-1 (90 to 100% survival). In contrast, vaccination with gH produced low neutralizing antibody titers and no protection against lethal HSV-1 challenge. Vaccination with gG produced no significant neutralizing antibody titer and no protection against ocular challenge. However, gG did provide modest, but statistically significant, protection against lethal intraperitoneal challenge (75% protection). Compared with the other glycoproteins, gG and gH were also inefficient in preventing the establishment of latency. Delayed-type hypersensitivity responses to HSV-1 at day 3 were highest in gG-, gH-, and gE-vaccinated mice, while on day 6 mice vaccinated with gC, gE, and gI had the highest delayed-type hypersensitivity responses. All seven glycoproteins produced lymphocyte proliferation responses, with the highest response being seen with gG. The same five glycoproteins (gB, gC, gD, gE, and gI) that induced the highest neutralization titers and protection against lethal challenge also induced some killer cell activity. The results reported here therefore suggest that in the mouse protection against lethal HSV-1 challenge and the establishment of latency correlate best with high preexisting neutralizing antibody titers, although there may also be a correlation with killer cell activity.

Characterization of baculovirus-expressed herpes simplex virus type 1 glycoprotein K

The DNA region encoding the complete herpes simplex virus type 1 (HSV-1) glycoprotein K (gK) was inserted into a baculovirus transfer vector, and recombinant viruses expressing gK were isolated. Four gK-related recombinant baculovirus-expressed peptides of 29, 35, 38, and 40 kDa were detected with polyclonal antibody to gK. The 35-, 38-, and 40-kDa species were susceptible to tunicamycin treatment, suggesting that they were glycosylated. The 38- and 40-kDa species corresponded to partially glycosylated precursor gK (pgK) and mature gK, respectively. The 29-kDa peptide probably represented a cleaved, unglycosylated peptide. The 35-kDa peptide probably represented a cleaved, glycosylated peptide that may be a precursor to pgK. Indirect immunofluorescence with polyclonal antibody to gK peptides indicated that the recombinant baculovirus-expressed gK was abundant on the surface of the insect cells in which it was expressed. Mice vaccinated with the baculovirus-expressed gK produced very low levels (< 1:10) of HSV-1 neutralizing antibody. Nonetheless, these mice were partially protected from lethal challenge with HSV-1 (75% survival). This protection was significant (P = 0.02). Despite some protection against death, gK-vaccinated mice showed no protection against the establishment of latency. Surprisingly, gK-vaccinated mice that were challenged ocularly with a stromal disease-producing strain of HSV-1 had significantly higher levels of ocular disease (herpes stromal keratitis) than did mock-vaccinated mice. In summary, this is the first report to show that vaccination with HSV-1 gK can provide protection against lethal HSV-1 challenge and that vaccination with an HSV-1 glycoprotein can significantly increase the severity of HSV-1-induced ocular disease.

Baculovirus-expressed glycoprotein E (gE) of herpes simplex virus type-1 (HSV-1) protects mice against lethal intraperitoneal and lethal ocular HSV-1 challenge

We have constructed a recombinant baculovirus expressing high levels of the herpes simplex virus type 1 (HSV-1) glycoprotein E (gE) in Sf9 cells. The expressed gE migrated on gels as a double band with apparent molecular weights of 68 and 70 kDa. The recombinant gE was glycosylated based on its susceptibility to tunicamycin treatment and was transported to the membrane of Sf9 cells based on indirect immunofluorescence. Mice vaccinated with gE developed high serum titers of HSV-1-neutralizing antibodies based on plaque reduction assays. gE vaccination also induced a strong delayed type hypersensitivity (DTH) response to HSV-1. In addition, mice vaccinated with the recombinant gE were protected from both intraperitoneal and ocular lethal HSV-1 challenge. To our knowledge, this is the first report in which vaccination with gE was shown to induce high neutralizing antibody titers, a DTH response, or protection against lethal HSV-1 challenge.

Fine mapping of the major latency-related RNA of herpes simplex virus type 1 in humans

In situ hybridization with synthetic oligonucleotides was used to fine map the extent and continuity of herpes simplex virus type 1 (HSV-1) latency-related RNA (LR RNA) in trigeminal ganglia of latently infected humans. A series of 34 20 residue oligonucleotides were employed to cover a 3 kb region of the HSV-1 genome to which the latency-related gene had previously been mapped. The 5' end of the main LR RNA transcript began approximately 1210 nucleotides downstream from the 3' end of the mRNA from the immediate early gene ICP0. The 3' end of the LR RNA overlapped the 3' end of the ICP0 mRNA by approximately 1000 nucleotides. A potential small intron was detected near the 3' end of the LR RNA.

Insulin-like growth factor I gene expression in GH3 rat pituitary cells: messenger ribonucleic acid content, immunocytochemistry, and secretion

Insulin-like growth factor I (IGF-I) is present in multiple tissues and cell types. Expression of the IGF-I gene was examined in GH3 cells, a rat pituitary tumor cell line secreting GH and PRL. Increasing concentrations of RNA extracts of GH3 cells yielded a linear increase in hybridization intensity with a 32P-labeled mouse IGF-I cDNA probe. Northern analysis of GH3 cells poly(A) RNA revealed IGF-I mRNA transcripts 1.3, 5.3, and 7.7 kilobases in size. Poly(A) RNA extracts of BALBc/3T3 fibroblasts, a cell line dependent on exogenous somatomedins for DNA synthesis, and of JEG-3 cells, a choriocarcinoma cell line, did not hybridize with the IGF-I cDNA probe. GH3 cells showed positive immunoperoxidase staining using a rabbit anti[Thr59]IGF-I antibody which was largely blocked by prior incubation of the antibody with excess IGF-I. Negligible background peroxidase activity was present in cells incubated with a rabbit nonimmune serum and PBS. Furthermore, BALBc/3T3 fibroblasts showed only weak specific staining with the IGF-I antibody. Finally, GH3 cells secreted IGF-I into the culture medium in a time-dependent fashion, while neither 3T3 nor JEG-3 cells produced detectable medium levels of the peptide after 72 h of incubation. As IGF-I is known to inhibit GH production by the pituitary, the data shown suggest that locally produced IGF-I may regulate GH secretion in an autocrine or paracrine fashion.

Autoregulation of pituitary growth hormone messenger ribonucleic acid levels in rats bearing transplantable mammosomatotrophic pituitary tumors

Female Wistar-Furth rats were implanted sc with GH3 rat pituitary tumor cells. Tumors were palpable by 4 weeks, and animals were killed periodically from 5-9 weeks. Tumor-bearing rats (n = 10) were heavier than their respective controls, reaching a weight of 372 +/- 3 by 9 weeks vs. 195 +/- 5 g in controls (mean +/- SE). Circulating serum GH levels increased in tumor-bearing animals from 218 +/- 50 to 9067 +/- 962 ng/ml. Serum insulin-like growth factor I (IGF-I) levels were elevated 3-fold in tumor-bearing rats. After death, pituitary glands were excised, and their total RNA was extracted. GH mRNA was assayed by dot hybridization of immobilized pituitary RNA with [32P]cDNA for rat GH. The hybridization signal was quantified by densitometry of autoradiographs. Pituitary rat GH mRNA levels were suppressed 50% in tumor-bearing animals after 5 weeks. By the end of the 9-week period, pituitary GH mRNA levels were undetectable in tumor-bearing animals. The results show that GH tumor-bearing animals exhibit high levels of circulating GH and IGF-I and suppressed endogenous pituitary GH mRNA levels. This may be caused by autoregulation of pituitary GH gene expression either at the level of the hypothalamus or by a direct effect of GH on the pituitary. Alternatively, the elevated levels of IGF-I may be responsible for the suppression of pituitary GH gene expression .

Insulin suppresses rat growth hormone messenger ribonucleic acid levels in rat pituitary tumor cells

Insulin has been shown to suppress growth hormone (GH) secretion by rat pituitary tumor cells (GH3) independently of glucose utilization. The effects of physiologic doses of insulin were therefore tested on cytoplasmic levels of GH messenger ribonucleic acid (mRNA) sequences. Insulin (3.5 nM) treatment of cells for 5 days suppressed the hybridization of cytoplasmic GH mRNA with 32P-cDNA for rGH by 50%. The three- to fourfold induction of cytoplasmic GH mRNA by hydrocortisone (1 microM) was also suppressed by insulin (3.5 nM) by 40%. The results show a direct suppression of cytoplasmic rGH mRNA concentration by physiologic doses of insulin. These findings may be due to either decreased rate of GH gene transcription, increased intracellular breakdown, or decreased nuclear-cytoplasmic transport of GH mRNA caused by insulin.