J/psi production versus centrality, transverse momentum, and rapidity in Au+Au collisions at square root sNN=200 GeV

The PHENIX experiment at the BNL Relativistic Heavy Ion Collider (RHIC) has measured J/psi production for rapidities -2.2<y<2.2 in Au+Au collisions at square root sNN=200 GeV. The J/psi invariant yield and nuclear modification factor RAA as a function of centrality, transverse momentum, and rapidity are reported. A suppression of J/psi relative to binary collision scaling of proton-proton reaction yields is observed. Models which describe the lower energy J/psi data at the CERN Super Proton Synchrotron invoking only J/psi destruction based on the local medium density predict a significantly larger suppression at RHIC and more suppression at midrapidity than at forward rapidity. Both trends are contradicted by our data.

Polymorphism of the ovine calpastatin gene

Calpastatin is a specific inhibitor of calpains and has been implicated in the regulation of beef tenderization. Variation in the ovine calpastatin gene (CAST) was investigated by amplification of a fragment containing the entire exon 6 using polymerase chain reaction (PCR), followed by single-strand conformational polymorphism (PCR-SSCP) analysis and DNA sequencing. Five novel SSCP patterns, representing five different sequences, were identified. Either one or two different sequences were detected in individual sheep and all the sequences identified shared high homology to the published ovine and bovine CAST sequences, suggesting that these sequences represent allelic variants of the ovine CAST gene. Sequence analysis revealed a non-synonymous amino acid variation in exon 6, which would result in a Gln/Leu substitution in Domain L of the mature protein. Considerable variation was detected in an intron region close to the acceptor splice site, with both sequence variation and length variation being observed in this region. Variation detected here might have an impact on both the function and expression of ovine calpastatin.

Scaling properties of azimuthal anisotropy in Au+Au and Cu+Cu Collisions at sqrt[s NN]=200 GeV

Differential measurements of elliptic flow (v2) for Au+Au and Cu+Cu collisions at sqrt[sNN]=200 GeV are used to test and validate predictions from perfect fluid hydrodynamics for scaling of v2 with eccentricity, system size, and transverse kinetic energy (KE T). For KE T identical with mT-m up to approximately 1 GeV the scaling is compatible with hydrodynamic expansion of a thermalized fluid. For large values of KE T mesons and baryons scale separately. Quark number scaling reveals a universal scaling of v2 for both mesons and baryons over the full KE T range for Au+Au. For Au+Au and Cu+Cu the scaling is more pronounced in terms of KE T, rather than transverse momentum.

Repression of intestinal drug metabolizing enzymes by the SV40 large T antigen

Toxic compounds such as carcinogens are removed from the body by the action of a series of detoxifying enzymes and transporters expressed in the liver and the small intestine. We have found that intestinal epithelial cells expressing the SV40 large T antigen (TAg) contain significantly lower levels of mRNAs, encoding several drug metabolizing/detoxifying enzymes and transporters compared to their non-transgenic littermates. In addition, TAg blocks the induction of these mRNAs by xenobiotics. The repression depends on an intact LXCXE motif in TAg, suggesting that inactivation of the retinoblastoma (Rb) family of tumor suppressors plays a role in the process. These results imply that a functional Rb pathway in the intestine is necessary for the expression of the detoxification system used to clear carcinogens, and suggest that loss of this tumor suppressor might alter susceptibility to chemical injury. In addition, the effect of TAg on the detoxification pathway appears to be tissue-specific, as its ectopic expression in the liver failed to suppress the P450 enzymes. The TAg-mediated suppression of drug metabolizing/detoxifying enzymes may have broad implications in the metabolism and mechanism of action of both carcinogens and prescription drugs.

Measurement of high-pT single electrons from heavy-flavor decays in p + p collisions at square root of s = 200 GeV

The momentum distribution of electrons from decays of heavy flavor (charm and bottom) for midrapidity absolute value of y < 0.35 in p + p collisions at square root of s = 200 GeV has been measured by the PHENIX experiment at the BNL Relativistic Heavy Ion Collider over the transverse momentum range 0.3 < pT < 9 GeV/c. Two independent methods have been used to determine the heavy-flavor yields, and the results are in good agreement with each other. A fixed-order-plus-next-to-leading-log perturbative QCD calculation agrees with the data within the theoretical and experimental uncertainties, with the data/theory ratio of 1.71+/-0.02stat+/-0.18sys for 0.3 < pT < 9 GeV/c. The total charm production cross section at this energy has also been deduced to be sigma cc = 567+/-57stat+/-193sys microb.

Obesity risk associated with the K121Q polymorphism of the glycoprotein PC-1 gene

BACKGROUND

Obesity is considered to be a multifactorial trait resulting from the combined influence of genetic and environmental determinants. Insulin resistance plays an important role in the development of obesity. Plasma-cell membrane differentiation antigene-1 (PC-1) inhibits insulin receptor signalling when overexpressed and thus causes insulin resistance. PC-1 gene polymorphism might be associated with adipocyte metabolism disturbance and energy imbalance. The purpose of this study was to determine whether K121Q polymorphism in PC-1 gene is involved in obesity susceptibility in Chinese Han population.

METHODS

The genotype of the polymorphism was determined using polymerase chain reaction-restriction fragment length polymorphism analysis for 338 unrelated subjects of Beijing, China. Their Body mass index (BMI), plasma glucose, total cholesterol, triglyceride, high-density lipoprotein cholesterol (HDL), free fatty acid (FFA) and insulin level were measured. Chi-square analyses were applied to test the significance differences in genotypic and allelic frequencies. Association studies were undertaken using the t-test and logistic regression analyses.

RESULTS

The obese had significantly higher frequency of KQ/QQ genotype or Q allele than non-obese in females (26.7% vs. 10.9%, p = 0.014 and 13.3% vs. 5.5%, p = 0.021). Significant elevation of insulin amongst the Q121 carrier women in obesity individuals and higher FFA level of Q121 carrier men in non-obese controls (BMI < or = 23 kg/m2) were observed. Binary logistic regression analysis revealed that PC-1 genotype together with higher glucose, total cholesterol, triglyceride and serum HDL were independently associated with the presence of obesity.

CONCLUSIONS

The observed genotype distributions revealed a significant association of PC-1 K121Q with obesity. PC-1 Q121 carriers are more likely to be insulin-resistant or get fatter in respect to KK subjects and carriers of the Q allele are at higher risk for the development of obesity in female.

Ultrastructure of the reticular basement membrane in asthmatic adults, children and infants

Reticular basement membrane (RBM) thickening in asthma is considered to be the result of subepithelial fibrosis. Thus, the RBM in asthma should contain an excess of fibrils identified as interstitial collagen and the ratio of fibril to matrix should be increased above normal levels. Electron micrographs of the RBM were compared with those of interstitial collagen deeper in the bronchial wall using endobronchial biopsy specimens from adult asthmatics (aged 18-41 yrs (n = 10)), children with difficult asthma (aged 6-16 yrs (n = 10)), wheezy infants with reversible airflow limitation (aged 0.3-2 yrs (n = 10)) and age-matched nonasthmatic controls: 10 adults, nine children and nine symptomatic infants with normal lung function. Fibrils in the RBM were significantly thinner (median (range) width 39 (30-52) nm versus 59 (48-73) nm), and fewer fibrils were banded than in the interstitial collagen (ratio of banded to non-banded fibrils 0.08 (0-0.17) versus 0.22 (0-1.3)). The ratio of fibrils to matrix in the thickened RBM of asthmatics did not differ from that of their respective controls (1.34 (0.63-2.49) versus 1.18 (0.31-2.6)). The ratio of fibril to matrix in the thickened reticular basement membrane of asthmatics is normal, and, contrary to what is expected in fibrosis, the fibrils do not resemble those of interstitial collagen.

Interleukin 1beta enhances non-rapid eye movement sleep and increases c-Fos protein expression in the median preoptic nucleus of the hypothalamus

Interleukin 1beta (IL-1) is a key mediator of the acute phase response in an infected host and acts centrally to coordinate responses to an immune challenge, such as fever and increased non-rapid eye movement (NREM) sleep. The preoptic area (POA) is a primary sleep regulatory center in the brain: the ventrolateral POA (VLPO) and median preoptic nucleus (MnPN) each contain high numbers of c-Fos protein immunoreactive (IR) neurons after sleep but not after waking. We hypothesized that IL-1 mediates increased NREM sleep through activation of these sleep-active sites. Rats injected intracerebroventricularly with IL-1 (10 ng) at dark onset spent significantly more time in NREM sleep 4-5 h after injection. This increase in NREM sleep was associated with increased numbers of Fos-IR neurons in the MnPN, but not in the VLPO. Fos IR in the rostral MnPN was significantly increased 2 h post IL-1 injection, although the percentage of NREM sleep in the preceding 2 h was the same as controls. Fos IR was also increased in the extended VLPO 2 h postinjection. Finally, Fos IR in the MnPN did not differ significantly between IL-1 and vehicle-treated rats that had been sleep deprived for 2 h postinjection, but it was increased in VLPO core. Taken together, these results suggest that Fos IR in the MnPN after IL-1 is not independent of behavioral state and may require some threshold amount of sleep for its expression. Our results support a hypothesis that IL-1 enhances NREM sleep, in part, through activation of neurons in the MnPN of the hypothalamus.

Sleep-promoting functions of the hypothalamic median preoptic nucleus: inhibition of arousal systems

Recent work supports the hypotheses developed by von Economo and Nauta and elaborated by Sallanon et al. that the POA contains a sleep-promoting output that opposes wake-promoting neuronal groups in the PH. The POA gives rise to descending pathways that terminate within wake-promoting populations in pLH, PH and midbrain. Current evidence suggests that this output originates in POA sleep-active GABAergic neurons. This output also seems to convey the signals of homeostatic drive. Disynaptic projections from the SCN to both MnPN and VLPO were recently identified. These may regulate the circadian control of sleep propensity. The hypothesis that the descending projections from POA sleep-active neurons to sites of arousal-related neurons originates in GABAergic neurons must be confirmed. Also to be further clarified is the anatomical distribution of putative sleep-active GABAergic neurons within the POA. Segregated groups have been found in the MnPN and VLPO, but unit recording studies of sleep-active neurons, lesion studies and local neurochemical application studies all indicate that sleep-active neurons may be found diffusely in the POA and adjacent areas. The MnPN has been shown previously to be involved in water balance and blood pressure regulation and to be responsive to hyperthermia. Our studies suggest that this nucleus also contains sleep-active, putative sleep-promoting neurons. However, interactions between sleep control and physiological variables must be considered. In particular, the details of neuronal basis of the coupling of warm-sensitive neurons in MnPN to the POA hypnogenic output has not been explored. It is also worth noting that both the VLPO and MnPN lie close to the ventricular and subarachnoid surface and are punctuated by radial arterioles. The possibility that the sleep-regulatory functions of these sites is coupled to physiological signals conveyed through epithelial cells has been suggested for the actions of PGD2 but has yet to be explored in detail for other putative hypnogens.

Factors affecting the stability of the performance of ambient fine-particle concentrators

This article describes a systematic evaluation of factors affecting the stability of the performance of Harvard ambient fine-particle concentrators, an essential requirement for controlled animal and human exposure studies that utilize these technologies. Phenomenological problems during the operation of the concentrator, including pressure drop increase and decrease in concentration enrichment, were statistically correlated with ambient air parameters such as temperature, relative humidity, PM2.5 mass concentration, and mass median diameter. The normalized hourly pressure drop across the concentrator was strongly associated (R2 = .81) with the product of ambient PM2.5 mass concentration and the difference between the vapor pressure downstream of the impactor nozzle and the saturation vapor pressure at the adiabatic expansion temperature (i.e., the temperature of the aerosol immediately downstream of the virtual impactors). From multiple regression analysis, the average enrichment factor was predicted reasonably well (R2 = .67) by aerosol mass median diameter and the normalized hourly pressure drop. Based on these results, we can anticipate in any given day whether an exposure study can be conducted without a considerable increase in the concentrator pressure drop, which might lead to an abrupt or premature termination of the exposure. As particle mass concentration and ambient dewpoint are the two main parameters responsible for raising the pressure drop across the concentrator, efforts should be made to either desiccate the ambient aerosol at days of high dewpoints, or to dilute the ambient PM at days of high concentrations, prior to drawing the aerosol through the virtual impactors. The latter approach is recommended on days of severe ambient pollution conditions because it is simpler and also makes it possible to maintain the appropriate concentration level delivered to the exposure chamber.

Role of epidermal growth factor and epidermal growth factor receptor on hemidesmosome complex formation and integrin subunit beta4

Epidermal growth factor (EGF) stimulates integrin beta4 expression and synthesis in corneal epithelium through ligand binding to the EGF receptor, receptor dimerization and activation of the intracellular domain. We hypothesized that inhibition of EGF receptor messenger RNA (mRNA) would block integrin beta4 expression, which is induced by EGF. We also tested the hypothesis that EGF would cause the degradation of hemidesmosomes in control and injured corneal organ cultures. Primary rabbit corneal epithelial cell cultures or corneas were cultured in keratinocyte medium in the presence or absence of an antisense 20-mer phosphorothioate oligonucleotide complementary to the initiation codon region of EGF receptor mRNA. Cells were also cultured in the presence or absence of EGF. Sense and scrambled oligonucleotides similarly modified were used as controls. The concentration of EGF receptor mRNA was semiquantitatively determined by reverse transcriptase/polymerase chain reaction (RT-PCR). We found that transfection did inhibit EGFR expression and migration of epithelial cells and also demonstrated that EGFR mediated expression of integrin beta4 mRNA. Injury induced a decrease in hemidesmosomes that was enhanced with EGF but was not caused by the presence of growth factor in unwounded tissue. These results indicate that injury causes the activation of EGFR but that EGF alone is not responsible for the degradation of hemidesmosomes and that other growth factors play a role in the complex repair of wounds in an avascular tissue.

Long-term effect on optic nerve of silicone oil tamponade in rabbits: histological and EDXA findings

PURPOSE

Side-effects after intravitreal use of silicone oil (SO) are not well defined and elucidated. The object of this study was to examine the influence and toxicity of SO on the optic nerve after vitrectomy with SO tamponade.

METHODS

We injected medical grade SO and emulsified SO into rabbit eyes after gas-mediated vitreous compression and examined the eyes by light microscopy (LM), transmission electron microscopy (TEM) and energy dispersive X-ray analysis (EDXA) (point analysis and area analysis) 6 months after injection. We compared the findings in the non-treated eyes and eyes with only gas-mediated vitreous compression with those in SO-injected eyes.

RESULTS

Vacuole-like structures were seen in the optic nerve posterior to the lamina cribrosa. In the group treated with only gas-mediated vitreous compression, the myelin structures were shown by TEM to be destroyed and replaced by glial tissue, while in groups injected with medical grade or emulsified SO severe destruction of the myelin sheath (myelinolysis) was observed. Silicone was identified at the electron-dense edges of the vacuoles by EDXA point analysis, but not in the vacuoles without electron-dense deposits. Dots of Si K alpha were not seen in the control groups, and dense dots were observed in SO-injected groups, by EDXA area analysis.

CONCLUSIONS

Some of the vacuoles might be artefacts caused by insufficient fixation or the operative procedure, but TEM showed almost no artefacts in the control optic nerve. Thus, most vacuoles may be SO storage sites. SO uptake into the optic nerve might play a role in the pathogenesis of optic nerve atrophy after SO injection.

[The role of beta3-adrenergic receptor Trp/Arg mutation in childhood obesity]

OBJECTIVE

To understand with greater clearness the role of beta3- adrenergic receptor Trp/Arg mutation in childhood obesity.

METHODS

One hundred and seventy-seven children, aged 6-12 years, were selected. The genotype was detected by restricted fragment length polymorphism, the children's dietaries were surveyed by a 3-day recalling and recording method. Their height, weight were measured, and the data on their living habits were collected from their parents.

RESULTS

The intake of total amount of food and energy of obese children were higher in children with Trp/Trp genotype, but there was no difference between the obese and non-obese children with Trp/Arg genotype. Among children with the Trp/Arg genotype, obese children were less active and did less exercise, they slept more, but there was no difference among children with Trp/Trp genotype.

CONCLUSION

The children with beta3-AR Trp/Arg mutation may become obese because of the low energy metabolism; less active and exercise may increase the risk of obesity.

[The outlook of using chitosan related materials in nerve regeneration]

Chitosan is a kind of biodegradable materials with excellent biocompatibility. This article interpreted the progress and outlook of using chitosan related materials in nerve regeneration from the following points: the positive charges on chitosan, its ability to adsorb proteins, the specific adhesion of nerve cells on chitosan, and the surface roughness, aperture and surface topography of chitosan.

Ultrastructural study of primary lacrimal adenocarcinoma

PURPOSE

Primary adenocarcinoma of the lacrimal gland is a rare malignant tumor of the orbit. Up to now, there has been no presentation of its ultrastructural features. The histopathological findings and fine structures of one case of adenocarcinoma of the lacrimal gland are described in the present work.

METHODS

The patient was a 59-year-old Japanese man with proptosis that had persisted for one month. A tumor was extirpated, and the tissues were prepared for light and electron microscopic examination.

RESULTS

Electron microscopic examination demonstrated that the tumor cells had well-developed microvilli and lumens. These ultrastructure features are similar to those seen in adenocarcinomas at other sites.

CONCLUSIONS

These observations suggest that the accurate diagnosis of rare malignant adenocarcinoma depends not only on routine techniques such as light microscopy of hematoxylin-eosin and PAS-diastase stained slides, but also on electron microscopic findings.

Primary structure and developmental expression of Dp ZP2, a vitelline envelope glycoprotein homolog of mouse ZP2, in Discoglossus pictus, one of the oldest living Anuran species

A glycoprotein of the Xenopus vitelline envelope, gp 69/64, which mediates sperm binding, is closely related to the components of ZPA family, such as the mouse zona pellucida ZP2. To test the generality of these findings, we studied Discoglossus pictus, a species evolutionary distant from Xenopus and identified as a protein of 63 kDa in the vitelline envelope. Preliminary studies suggest that this protein may bind sperm at fertilization. We found that the 63-kDa protein is glycosylated and contains both N- and O-linked chains. We have cloned the cDNA encoding the Discoglossus protein of 63 kDa (Dp ZP2) by screening a Discoglossus cDNA library using Xenopus gp 69/64 cDNA as a probe. Analysis of the deduced sequence of Discoglossus protein revealed 48% identity with Xenopus gp 69/64 and 37-40% identity with mouse ZP2. The sequence conservation included a ZP domain, a potential furin cleavage site and a putative transmembrane domain. The N-terminus region of Dp ZP2 was 40% identical to the corresponding region of Xenopus gp 69/64 which has been shown to be essential for sperm binding to the VE. Although, as of yet, there is no evidence for sperm binding at the Dp ZP2 N-terminus, it is interesting that in this region three potential O-glycosylation sites are conserved in both species, in contrast to N-glycosylation sites. It was found that the Dp ZP2 mRNA is expressed in stage 1 oocytes and in the follicle cells surrounding the oocyte. Similarly, in Xenopus oocytes, the gp 69/64m RNA, was found in the oocytes, as well as in the somatic cells. Mol. Reprod. Dev. 59:133-143, 2001.

The characterization of prepro-Insulin-like growth factor-1 Ea-2 expression and Insulin-like growth factor-1 genes (devoid 81 bp) in the zebrafish ( Danio rerio )

In this study, we cloned zebrafish (Danio rerio) IGF-1 cDNA and gene from zebrafish brain cDNA library and adult zebrafish genomic library, respectively. Based on two cDNAs sequence with different length of 5'- and 3'-untranslated region (5UTR and 3UTR) and one nucleotide difference at glutamine (A9, CAG) of A domain represented at IGF-1 sequence. One of zebrafish IGF-1 genes named as IGF-1a gene. The zebrafish IGF-1a gene spanned approximately 15 kb and is divided into five exons. The results of IGF-1 cDNA and genomic Southern blotting, all indicated that the zebrafish have more than one IGF-1 gene. The genomic organization of zebrafish IGF-1a gene in an exon is devoid of 81 bp segment which is located at 3' end of exon 3 encoded 27 amino acid of E domain. The segment of 27 amino acid exists in known teleost IGF-1 genes but is absent in zebrafish IGF-1 gene. The E domain of zebrafish IGF-1 Ea-2 is encoded by 3' end of exon 3 (16 amino acid), full of exon 4 (12 amino acid) and exon 5 (19 amino acid). The sequence data revealed the zebrafish IGF-1a gene encoded IGF-1a Ea-2 mRNA. In combination RT-PCR with Southern blotting, zebrafish IGF-1 genes abundantly expressed IGF-1 Ea-2 mRNA in all tested adult tissues and developmental stages of embryo. The IGF-1 Ea-2 mRNA was first detected during embryo development from blastula stage to hatching, during yolk absorption and at feeding. All these findings suggest that the expression of pro-IGF-1 Ea-2 is not controlled by alternative splicing but alternative gene usage in the zebrafish.

Specific hydraulic conductivity of corneal stroma as seen by quick-freeze/deep-etch

Previous studies of the hydraulic conductivity of connective tissues have failed to show a correspondence between ultrastructure and specific hydraulic conductivity. We used the technique of quick-freeze/deep-etch to examine the ultrastructure of the corneal stroma and then utilized morphometric studies to compute the specific hydraulic conductivity of the corneal stroma. Our studies demonstrated ultrastructural elements of the extracellular matrix of the corneal stroma that are not seen using conventional electron microscopic techniques. Furthermore, we found that these structures may be responsible for generating the high flow resistance characteristic of connective tissues. From analysis of micrographs corrected for depth-of-field effects, we used Carmen-Kozeny theory to bound a morphometrically determined specific hydraulic conductivity of the corneal stroma between 0.46 x 10(-14) and 10.3 x 10(-14) cm2. These bounds encompass experimentally measured values in the literature of 0.5 x 10(-14) to 2 x 10(-14) cm2. The largest source of uncertainty was due to the depth-of-field estimates that ranged from 15 to 51 nm; a better estimate would substantially reduce the uncertainty of these morphometrically determined values.

Male accessory gland derived factors can stimulate oogenesis and enhance oviposition in Helicoverpa armigera (Lepidoptera: Noctuidae)

In Helicoverpa armigera, female moths began to lay eggs on the third day after emergence. Mating stimulated earlier egg maturation/oogenesis (P = 0.002) and oviposition (P << 0.01). We established a suitable bioassay model for the influence of male accessory glands (MAG) on the physiology of virgin females: Crude extracts of MAG (2- to 3-day-old) were injected into 2-day-old virgin females, and the injected females were dissected 20 h after mating. It was shown that crude extracts of MAG stimulated earlier egg maturation (P < 0.001) and oviposition (the oviposition ratio was more than 2 times the ratio of the control). Proteinaceous components in crude extracts purified by fractionation and sub-fractionation in reverse phase high performance liquid chromatography also stimulated earlier egg maturation (P < 0.01) and ovipositon (more than 2 times the ratio of the control), and we called them the oogenesis and ovipostion factors (OOSF). With SDS-PAGE, the molecular mass of the bands from OOSF was estimated to be between 55-66 KD. Arch.

Optic nerve changes in zinc-deficient rats

In this study the optic nerve changes in zinc (Zn)-deficient rats are examined. Zinc is one of the essential trace elements and is known to be related to optic nerve diseases such as ethambutol neuropathy. However, the effect of Zn on the optic nerve has not been studied experimentally in animals. We used 3 week old weanling male Wistar Kyoto rats weighing 40-50 g. Rats were fed a Zn-deficient diet containing 0.007 mg of Zn per 100 g, all other nutrients and distilled and deionized water. The same water supplemented with 3 mg Zn per 100 g was given to the control group. After 4 or 7 weeks on a Zn-deficient diet, the optic nerve was examined with an electron microscope. A recovery group was fed a Zn-containing diet for 5 weeks after 7 weeks on the Zn-deficient diet. The serum Zn levels of the deficient group were significantly decreased at both 4 and 7 weeks. Most of the Zn-deficient rats showed hair loss around the eyes and on the extremities. Ultrastructural findings were as follows. The number of myelinated axons of Zn-deficient rats at 4 and 7 weeks were significantly decreased and the myelin sheaths were significantly thinner in the Zn-deficient groups and in the recovery group. Unmyelinated axons were more numerous than in the control rats. Destruction of myelin and proliferation of glial cells were found in the optic nerves of Zn-deficient rats. This study suggests that the optic nerve needs Zn for the maintenance of its cell structure and even if Zn is supplied to the Zn-deficient rats, destruction of the myelin structure may continue. Zn-deficiency induce a decrease of myelinated nerve fibers, and it is thought that optic neuropathy in patients treated with some drugs such as ethambutol may be a secondary change due to Zn-deficiency following drug administration.

Anti-inflammatory and lung function effects of montelukast in asthmatic volunteers exposed to sulfur dioxide

BACKGROUND

Sulfur dioxide (SO(2)) gas may induce acute asthmatic responses when inhaled by individuals in the setting of community or occupational air pollution during exercise. Some asthma medications mitigate the SO(2) response, which is not fully understood but appears to involve multiple mechanisms.

OBJECTIVE

We tested the hypothesis that pretreatment with the cysteinyl-leukotriene inhibitor montelukast sodium protects against the inflammatory and bronchoconstrictive effects of SO(2) in the airways of asthmatic subjects.

METHODS

Asthmatic volunteers (enrolled, 12 subjects; completed study, 11 subjects) were exposed to 0.75 ppm SO(2) for 10-min periods during exercise (mean ventilation, 35 L/min) and were exposed similarly to filtered air (control condition) after double-blinded pretreatments with montelukast (10 mg/d for 3 days) and placebo.

RESULTS

After montelukast pretreatment, specific airways resistance, FEV(1), symptoms, and eosinophil counts in induced sputum showed statistically and clinically significant improvements in preexposure measurements and/or decreased responses to SO(2) exposure or exercise. The mean FEV(1) immediately after exposure was 95% of baseline FEV(1) with montelukast pretreatment vs 82% with placebo.

CONCLUSION

Montelukast significantly protects against airways eosinophilic inflammation and bronchoconstriction from SO(2) exposure during exercise. This implies a role for leukotrienes in SO(2)-induced lung effects.

Subregional organization of preoptic area/anterior hypothalamic projections to arousal-related monoaminergic cell groups

Pathways mediating the generation and/or maintenance of sleep reside within the preoptic/anterior hypothalamus (POAH). Reproduction, water balance, thermoregulation, and neuroendocrine functions are also associated with POAH, but it is not fully understood whether sleep is consolidated with these behavioral and physiological functions, or whether sleep-related circuitry is segregated from other POAH regions. Recent studies indicate that sleep mechanisms may be localized to the ventrolateral preoptic area (VLPO) and that this region sends inhibitory projections to waking/arousal-related neurons in the histaminergic tuberomammillary nucleus (TM), the noradrenergic locus coeruleus (LC), and the serotonergic dorsal raphe (DR). The present study is a quantitative investigation of preoptic area efferents to these monoaminergic groups. The results demonstrate that biotinylated dextran injections in the VLPO region reveal a robust innervation of TM that was as much as five times greater than innervation derived from other POAH subregions. The innervation of TM originated almost exclusively from injection sites in the region of galanin neurons. VLPO projections to the LC were moderately dense and were greater than in other POAH regions except for equivalent input from the medial preoptic area. Projections to the dorsal raphe were equivalent to LC innervation and were generally two to three times greater from VLPO than from other POAH regions, except for projections from the lateral preoptic region, which were similar in magnitude. The rostral and caudal levels projected more to the TM, whereas the midrostral region of VLPO strongly innervated the LC core. These findings, with recent studies demonstrating medial and lateral extensions of the sleep-related VLPO neuronal group, indicate that descending arousal state control may be mediated by this specific galaninergic/gamma-aminobutyric acid (GABA)ergic cell group.

Retinal changes in magnesium-deficient rats

The purpose of the present study is to investigate the retina in magnesium (Mg) deficiency and elucidate the local functions of trace elements. After delivery, mother Wistar Kyoto rats were fed a low Mg diet containing 0.1 mg Mg per 100 g diet with all other nutrients and distilled and deionized water. Infant rats were suckled by their mother rats for 21 days and then fed the same Mg-deficient diet. Control mother rats were fed commercial rat pellets containing 24 mg Mg per 100 g diet and all other nutrients. The retinas were examined by electron microscopy and secondary ion mass spectrometry (SIMS) microscopy at 6 weeks of age. In the Mg-deficient rats serum Mg levels were significantly lower and calcium (Ca) levels higher than in the control rats. The retinas of Mg-deficient rats showed multifocal necrosis in the pigment epithelial cells; photoreceptor cell outer segments were deformed near the necrotic cells, and some pigment epithelial cells contained many lamellar bodies. Many photoreceptor cell nuclei showed pyknotic (apoptosis-like) changes. SIMS images showed lower Mg concentration throughout the retina of the Mg-deficient rats, and the ratio of Ca to Mg concentration was significantly higher than in the control rats. Mg deficiency induces multifocal necrosis in the retinal pigment epithelial cells and pyknotic (apoptosis-like) changes in the photoreceptor cell nuclei. The changes in Mg-deficient retinas may be due to an imbalance in the distribution of Mg and Ca trace elements.

Applying secondary ion mass spectrometry to the analysis of elements in goblet cells of conjunctiva

We investigated the location of elements in the goblet cells of rat conjunctiva by analyzing ion images produced by secondary ion mass spectrometry (SIMS) and comparing them with those produced by energy dispersive X-ray analyser (EDX). Conjunctivas of normal Spraque-Dawley rats were quenched in propane prechilled liquid nitrogen. Semi-thin sections were made with a cryo-ultramicrotome, freeze-dried, carbon-coated and observed under a light microscope, SIMS and scanning electron microscope (SEM). In the element analysis by SIMS, images of positive ions were examined with an O2+ primary ion source and images of negative ions with a Ga+ ion source. The same sections were observed and analysed with SEM-EDX. Morphological features and images of elements with SIMS and EDX were compared. Na, Mg, K, and Ca were detected as positive ions and OH, CN, P, S, and Cl as negative ions with SIMS, but C, N, O, Na, Mg, P, S, Cl, K, and Ca were detected with EDX. The spatial resolution of SIMS in element location was higher than that of EDX. Many elements were clearly located in the goblet cells on ion images by SIMS. Element ion images were demonstrated more densely in goblet cells than in other parts within conjunctiva and by SIMS compared to EDX. SIMS is a useful method for the detection of elements and their locations in ocular tissues and cells.

[Impact of high temperature on testicular growth and development of valuable silkworm Antheraea yamamai(Lepidoptera: Saturiidae)]

The results indicated that high temperature had a significant impact on the growth and development of testis in Japanese oak silkworm Antheraea yamamai. The testicular size of the 3rd and 4th instar larvae increased within the range from 20 to 29 degrees C, and slightly decreased at 32 degrees C. While in the 5th instar, it decreased within the range from 20 to 26 degrees C, with the biggest size at 20 degrees C. The testis was almost hard to grow and develop because the larvae could not survive at 29 to 32 degrees C. When the mature larvae were treated at 32 degrees C at the beginning of coconing or at the 1st or 6th day of pupating, the growth of testicular size and spermatogenesis were significantly arrested, and the sperm number and the content of soluble protein in the testis markedly decreased. When the male moth of the 1st day was treated at 32 degrees C, the activity of the sperms in the testis obviously decreased, in contrast to the treatment at 20 degrees C. It is concluded that for the egg raising of the silkworm, its mature larvae, puape in cocoons and male moths should not be exposed to 32 degrees C from cocooning to adult stage. The proper temperature for rearing 3rd, 4th and 5th instar larvae was discussed.

Sleep-related c-Fos protein expression in the preoptic hypothalamus: effects of ambient warming

Preoptic area (POA) neuronal activity promotes sleep, but the localization of critical sleep-active neurons is not completely known. Thermal stimulation of the POA also facilitates sleep. This study used the c-Fos protein immunostaining method to localize POA sleep-active neurons at control (22 degrees C) and mildly elevated (31.5 degrees C) ambient temperatures. At 22 degrees C, after sleep, but not after waking, we found increased numbers of c-Fos immunoreactive neurons (IRNs) in both rostral and caudal parts of the median preoptic nucleus (MnPN) and in the ventrolateral preoptic area (VLPO). In animals sleeping at 31.5 degrees C, significantly more Fos IRNs were found in the rostral MnPN compared with animals sleeping at 22 degrees C. In VLPO, Fos IRN counts were no longer increased over waking levels after sleep at the elevated ambient temperature. Sleep-associated Fos IRNs were also found diffusely in the POA, but counts were lower than those made after waking. This study supports a hypothesis that the MnPN, as well as the VLPO, is part of the POA sleep-facilitating system and that the rostral MnPN may facilitate sleep, particularly at elevated ambient temperatures.

A novel 5-HT(2) antagonist, sarpogrelate hydrochloride, shows inhibitory effects on both contraction and relaxation mediated by 5-HT receptor subtypes in porcine coronary arteries

In isolated porcine coronary arteries, concentrations of 5-HT (10(-8) to 3x10(-5) mol/l), alpha-methylserotonin (alpha-Me-5-HT, 10(-8) to 3x10(-5) mol/l) and ergonovine (10(-9) to 3x10(-4) mol/l) produced contraction, whereas high concentrations (10(-5) to 10(-4) mol/l) of these drugs produced relaxation. Both sarpogrelate and ketanserin produced rightward shifts of contraction concentration-response curves induced by 5-HT and alpha-Me-5-HT at the concentration from 10(-9) to 3x10(-5) mol/l, and only sarpogrelate inhibited the relaxation at high concentrations of 5-HT and displayed 155% of maximal contraction at 10(-4) mol/l 5-HT. On the other hand, sarpogrelate and ketanserin did not show any inhibitory effects on the relaxation induced by high concentrations of ergonovine. These results suggested that sarpogrelate and ketanserin show different inhibitory effects on the relaxation induced by high concentrations of 5-HT, indicating that these two drugs may have different affinities to 5-HT receptor subtypes that may be involved in relaxation.

Effects of temperature and salinity on nitrogenous excretion by Litopenaeus vannamei juveniles

Excretion rates of ammonia-N, nitrite-N, nitrate-N, and dissolved organic nitrogen (DON) for juvenile Litopenaeus vannamei (3.85+/-0.83 g) were quantified in response to nine different combinations of temperature (24, 28, and 32 degrees C) and salinity (10, 25, and 40 ppt) under laboratory conditions. Results indicated that L. vannamei is ammonotelic, with ammonia-N accounting for 61.9-84.3% of total nitrogen (TN) excretion. There were significant effects of temperature and salinity, but no significant interaction between them, on ammonia-N excretion rate (R(AN)). R(AN) increased with increasing temperature, over the interval 24-32 degrees C. R(AN) was lower at 25 ppt than at 10 and 40 ppt, at all temperatures. DON excretion rate (R(DON)) was not significantly influenced by either temperature or salinity; the overall mean R(DON) was about 5.24 µg-N g -1 h -1. However, the percentages of DON in TN (P(DON)) varied from 15.4 to 36.4% under the various temperature-salinity combinations. P(DON) at 28 and 32 degrees C was significantly lower than at 24 degrees C, and P(DON) at 10 ppt was significantly lower than at 25 and 40 ppt. Only very small amounts of nitrogen were excreted by L. vannamei as nitrite-N and nitrate-N.

Localization of occludin, ZO-1, and pan-cadherin in rabbit ciliary epithelium and iris vascular endothelium

Previous studies have used conventional electron microscopy and freeze fracture to identify the morphological equivalents of the blood-aqueous barrier in the mammalian eye. These equivalents are the tight junctions that form a part of the apicolateral junctional complex between adjacent non-pigmented ciliary epithelial cells and the tight junctions present between endothelial cells of the iris vasculature. Recent investigations have begun to unravel the molecular assembly of the tight junction and some variability has been found. Our goal in the present study was to probe the ciliary epithelium and iris vascular endothelium of the rabbit eye to determine if certain molecular constituents associated with tight junctions in other tissues are also present as parts of the blood-aqueous barrier. The selected constituents were occludin, ZO-1, and a representative, adherens junction-related cadherin. Immunohistochemical and immunoelectron microscopic methods were used. The results showed that occludin was distributed exclusively at known locations of tight junctions. ZO-1 was also expressed at these locations but its distribution extended beyond that of occludin, along the adjacent membranes. Pan-cadherin was expressed ubiquitously within the ciliary epithelium and negligibly in iris vascular endothelium. Our results demonstrate that occludin and ZO-1 are integral components of the blood-aqueous barrier of the normal rabbit eye.

[Treatment of hemangioma in oral and maxillofacial region with pingyangmycin injection]

OBJECTIVE

To investigate the indication and result in hemangioma in oral and maxillofacial region with Pingyangmycin injection.

METHODS

1282 patients (554 males and 728 females) with hemangioma in oral and maxillofacial region have been treated in our hospital during the 10-year period from May 1990 to March 1999. The patients range between 0.5-84 years old. Lip, cheek and tongue were usually involved. 1211 patients were treated with injection of Pingyangmycin(about 0.89 mg/ml) and dexamethasone (about 0.55 mg/ml), 1 time/1-2 weeks.

RESULTS

The curative rates of cavernous hemangioma and strawberry hemangioma were 93.87% and 84.90%, but that of plexiform hemangioma was 22.22% and those of portwine stain and central hemangioma of the jaws were 0%, respectively. Serious complications associated with Pingyangmycin injection, such as pulmonary fibrosis were not seen.

CONCLUSION

Injection of Pingyangmycin is selective primary method for cavernous and strawberry hemangioma treatment.

[Phytotoxic effect of soil cadmium pollution on ramie]

A microplot locating experiment was conducted to study the phytotoxic effect of adding Cd in soil on ramie plants. The results showed that the contents of chlorophyll a and b of leaf, and the photosynthesis productivity of ramie plant were significant reduced by the addition of Cd. As the content of soil Cd reached to 14 mg.kg-1, the biomass yield of the above-ground part of ramie plants was 20% lower than the control, and was 50% lower when soil Cd content was at 100 mg.kg-1. The number of effective tillers was a main factor affecting the yield of ramie raw fibers, and Cd addition had a relatively small effect on the quality of raime fibers. It is suggested that a synthetical technology of soil treatment and agronomic measures should be applied to eliminate the toxic effect of soil Cd and to enhance the resistance of plant against soil Cd pollution when employing ramie as the alternative of food and vegetable crops in a Cd-polluted region, which is also important for a higher yield of ramie.

Inhibitory effects of a newly synthesized 5-HT2 receptor antagonist, AT-1015 (N-[2-[4-(5H-dibenzo[a,d]cyclohepten-5-ylidene)piperidino]-ethyl]-1-for myl-4-piperidinecarboxamide monohydrochloride monohydrate), on contraction and relaxation of pig coronary arteries induced by 5-HT and alpha-methylserotonin: comparison with ketanserin

Inhibitory effects of a newly synthesized 5-HT2 receptor antagonist, AT-1015 (N-[2-[4-(5H-dibenzo[a,d]cyclohepten-5-ylidene)piperidinolethyl ]-1-formyl-4-piperidinecarboxamide monohydrochloride monohydrate) on contraction and relaxation of coronary arteries of pig hearts mediated by 5-HT2 subtypes were evaluated and these results were compared with those of ketanserin. Contraction and relaxation were determined by adding 5-HT or alpha-methylserotonin (alpha-Me-5-HT) as agonists. Although ketanserin induced rightward shifts of contraction, AT-1015 inhibited the maximal response. In addition, ketanserin inhibited relaxation induced by high concentration of agonists, but there were no inhibitory effects of AT-1015 on relaxation. Thus, these results suggest that AT-1015 is a strong non-competitive 5-HT2 antagonist in porcine coronary arteries and that this drug clearly exhibited different effects on the contraction and relaxation of coronary arteries of pig hearts from those of ketanserin.

Quality of spirometry test performance in children and adolescents : experience in a large field study

STUDY OBJECTIVE

To determine the ability of children and adolescents to meet the American Thoracic Society (ATS) goals for spirometry quality that were based on results from adults.

DESIGN

Observational.

PARTICIPANTS

More than 4,000 public school students, ages 9 to 18 years.

MEASUREMENTS

Spirometry was performed annually for 3 years, with the recording of maneuver quality measures of forced expiratory time, end-of-test volume, back-extrapolated volume, and time to peak expiratory flow (PEFT), and the recording of differences between best and second-best FVC, FEV(1), and peak expiratory flow (PEF) values.

RESULTS

Regression analyses showed significant influences of participant age, gender, ethnicity, size, clinical status, and previous testing experience, as well as differences among individual test technicians. In general, these influences were small and explained little of the variance in performance. On average, children with a history of asthma or wheeze performed better quality spirometry than did others. Only PEFT improved significantly from year to year. Overall, only 15% of girls' tests and 32% of boys' tests met the PEFT criterion derived from adults in the Lung Health Study.

CONCLUSION

Most of the children met adult-based ATS goals for spirometry test performance. Age group-specific criteria are needed to ensure adequately fast PEFT and reproducible PEF values.

Discharge modulation of rat dorsal raphe neurons during sleep and waking: effects of preoptic/basal forebrain warming

In cats, putative serotonergic neurons (PSNs) recorded from the dorsal raphe nucleus (DRN) across the sleep-wake cycle exhibit the so-called rapid eye movement sleep-off (REM-off) discharge pattern. Since, the sleep-wake discharge patterns of DRN neurons in behaving rats is poorly known, the present study examined this neuronal populations. The PSNs recorded in this study exhibited: (1) progressive decrease in discharge rate from waking to NREM to REM sleep; (2) long action potential duration, and (3) reduction of discharge rate after systemic administration of a selective 5-HT(1A) agonist, (+/-)-8-hydroxy-2-(di-n-propylamino) tetralin hydrobromide (8-OH-DPAT). Evidence supports the hypothesis that NREM sleep is modulated by thermoregulatory mechanisms localized in the preoptic area and adjacent basal forebrain (POA/BF). We previously reported that POA/BF warming suppresses the discharge of wake-promoting neurons in the posterior hypothalamus and the basal forebrain. Since the DRN is one component of the brainstem arousal system and receives projections from POA/BF, we examined the effects of local POA/BF warming by 1.5-2.0 degrees C during waking on the discharge of DRN neurons. POA/BF warming reduced the discharge in 14 of 19 PSNs and in 12 of 17 other wake-related neurons in the DRN. DRN neuronal discharge reduction occurred without accompanying EEG frequency or behavioral changes. These results suggest that PSNs recorded in DRN in unrestrained and unanesthetized rats exhibit a "wake-active REM-off" discharge pattern and further support the hypothesis that the POA/BF warm-sensitive hypnogenic system induces sleep by a coordinated inhibition of multiple arousal systems including that modulated by the DRN.

Pulmonary function in chronic spinal cord injury: a cross-sectional survey of 222 southern California adult outpatients

OBJECTIVES

To evaluate risk factors for respiratory morbidity in chronic spinal cord injury (SCI).

SETTING

Model SCI care system based at an urban public rehabilitation medical center.

DESIGN

Case series with evaluation of pulmonary function by conventional spirometric testing.

PARTICIPANTS

Two hundred twenty-two adults with SCI of more than 1-year duration who were not chronically dependent on mechanical ventilation, including 98 with tetraplegia (62 with complete and 26 with incomplete motor lesions) and 124 with paraplegia (87 with complete and 37 with incomplete motor lesions).

MAIN OUTCOME MEASURES

Forced vital capacity (FVC), forced expired volume in 1 second (FEV1), and peak expiratory flow rate (PEFR), all measured in the supine and erect seated positions and compared with predicted normal values for industrial workers.

RESULTS

FVC and FEV1 were normal in persons with low-level paraplegia who had never smoked, but both decreased similarly with rising SCI level, more markedly in those with tetraplegia. PEFR decreased with rising SCI level. Incomplete lesions mitigated function loss in those with tetraplegia. In middle-aged individuals with tetraplegia, longer duration of injury was associated with greater function loss, independent of age. Current smokers showed excess function loss, except for those with high tetraplegia. Most people with complete tetraplegia showed FVC and FEV1 increases in the supine position relative to the erect position.

CONCLUSIONS

Pulmonary function is compromised by most lesions of the spinal cord, even in those with paraplegia, and is affected relative to the level of lesion. Efforts to help SCI patients minimize respiratory complications-in particular, assistance in smoking cessation-should be given high priority.

Tyrosine phosphorylation: a critical component in the formation of hemidesmosomes

Our goal was to evaluate the role of tyrosine phosphorylation in the complete formation of hemidesmosomes that occurs during development or during remodeling after injury. A corneal organ culture system was used to study hemidesmosome formation as it would occur in an intact tissue. Phosphorylation of the integrin subunit beta 4 and bullous pemphigoid antigen-1 (BPAG-1) was examined, as these proteins are known to play a role in linking the electron-dense plaques along the basal surface with the intermediate filaments to complete the formation of hemidesmosomes. Corneal epithelial sheets were placed on substrata that contained an intact basal lamina or basal laminae that had been either modified or removed. These constructs were incubated for up to 18 h, and hemidesmosome formation was evaluated by using transmission electron microscopy. When epithelial sheets were placed on intact basal laminae and incubated in the presence of the tyrosine kinase inhibitor genistein (200 microM), hemidesmosome formation was impaired. The formation of electron-dense regions was delayed, and no association of intermediate filaments was detected. Results were confirmed by biochemical studies. When the epithelium and underlying proteins were extracted and immunoprecipitated with beta 4 or BPAG-1, tyrosine phosphorylation decreased in the presence of genistein. In addition, the phosphorylation of beta 4 decreased when epithelial sheets were incubated on substrata from which the basal lamina had been removed or altered. Thus, a reduction in phosphorylation of tyrosine residues impairs the formation of mature hemidesmosomes, and substrata that fail to support hemidesmosome formation also demonstrate decreased phosphorylation of tyrosine residues.

Air pollution and daily hospital admissions in metropolitan Los Angeles

We used daily time-series analysis to evaluate associations between ambient carbon monoxide, nitrogen dioxide, particulate matter [less than and equal to] 10 microm in aerodynamic diameter (PM(10)), or ozone concentrations, and hospital admissions for cardiopulmonary illnesses in metropolitan Los Angeles during 1992-1995. We performed Poisson regressions for the entire patient population and for subgroups defined by season, region, or personal characteristics, allowing for effects of temporal variation, weather, and autocorrelation. CO showed the most consistently significant (p<0.05) relationships to cardiovascular admissions. A wintertime 25th-75th percentile increase in CO (1.1-2.2 ppm) predicted an increase of 4% in cardiovascular admissions. NO(2), and, to a lesser extent, PM(10) tracked CO and showed similar associations with cardiovascular disease, but O(3) was negatively or nonsignificantly associated. No significant demographic differences were found, although increased cardiovascular effects were suggested in diabetics, in whites and blacks (relative to Hispanics and Asians), and in persons older than 65 years of age. Pulmonary disease admissions associated more with NO(2) and PM(10) than with CO. Pulmonary effects were generally smaller than cardiovascular effects and were more sensitive to the choice of model. We conclude that in Los Angeles, atmospheric stagnation with high primary (CO/NO(2)/PM(10)) pollution, most common in autumn/winter, increases the risk of hospitalization for cardiopulmonary illness. Summer photochemical pollution (high O(3)) apparently presents less risk.

Air pollution and daily hospital admissions in metropolitan Los Angeles

We used daily time-series analysis to evaluate associations between ambient carbon monoxide, nitrogen dioxide, particulate matter [less than and equal to] 10 microm in aerodynamic diameter (PM(10)), or ozone concentrations, and hospital admissions for cardiopulmonary illnesses in metropolitan Los Angeles during 1992-1995. We performed Poisson regressions for the entire patient population and for subgroups defined by season, region, or personal characteristics, allowing for effects of temporal variation, weather, and autocorrelation. CO showed the most consistently significant (p<0.05) relationships to cardiovascular admissions. A wintertime 25th-75th percentile increase in CO (1.1-2.2 ppm) predicted an increase of 4% in cardiovascular admissions. NO(2), and, to a lesser extent, PM(10) tracked CO and showed similar associations with cardiovascular disease, but O(3) was negatively or nonsignificantly associated. No significant demographic differences were found, although increased cardiovascular effects were suggested in diabetics, in whites and blacks (relative to Hispanics and Asians), and in persons older than 65 years of age. Pulmonary disease admissions associated more with NO(2) and PM(10) than with CO. Pulmonary effects were generally smaller than cardiovascular effects and were more sensitive to the choice of model. We conclude that in Los Angeles, atmospheric stagnation with high primary (CO/NO(2)/PM(10)) pollution, most common in autumn/winter, increases the risk of hospitalization for cardiopulmonary illness. Summer photochemical pollution (high O(3)) apparently presents less risk.

Arginine deiminase inhibits proliferation of human leukemia cells more potently than asparaginase by inducing cell cycle arrest and apoptosis

L-Asparaginase is used for the treatment of acute leukemias, but is sometimes ineffective or associated with severe side-effects. We report here that the enzyme arginine deiminase is approximately 100-fold more potent than L-asparaginase in inhibiting the proliferation of cultured human lymphatic leukemia cell lines while it appears to be less effective in leukemia cells of myeloid origin. The inhibition of cell proliferation involves cell growth arrest in the G1- and/or S-phase and eventually apoptotic cell death. Our results suggest the possibility of a future use of arginine deiminase for the therapy of leukemia.

Biochemistry and physiology of overwintering in the mature larva of the pine needle gall midge, Thecodiplosis japonensis (Diptera: cecidomyiidae) in Korea

The pine needle gall midge, Thecodiplosis japonensis, overwinters in the soil as a third instar mature larva. The metabolic and physiological compensations and adjustments during its overwintering and acclimation were studied. Field-sampled larvae in 1997/98 winter showed a significant increase in whole-body trehalose by January (5.71 +/- 0.09 vs. 9.41 +/- 0.42 mg/g wet weight) along with a more significant decrease in whole-body glycogen (16.25 +/- 0.18 vs. 5.65 +/- 0.45 mg/g wet weight). Afterwards, there was a partial reconversion of trehalose to glycogen. Moreover, trace amounts of glycerol and steady content of glucose as potential cryoprotectants were found during the overwintering period. Temperature acclimation of field-sampled larvae affects interconversion between trehalose and glycogen. Trehalose accumulation does not affect the larval supercooling capacity. The mean supercooling point of the larvae remained nearly constant at about -20 degree he winter and was unchanged after temperature acclimation. Low temperature survival experiment suggested that the larvae adopt a freeze-avoiding strategy for overwintering.

Left prefrontal cortex activation during semantic encoding accessed with functional near infrared imaging

OBJECTIVE

To investigate the left prefrontal lobe activation during semantic and non-semantic encoding tasks with functional near-infrared imaging (fNIRI) technique.

METHOD

22 healthy subjects were assigned semantic encoding and non-semantic encoding tasks. During semantic encoding tasks, subjects were asked to make a meaningful sentence including two unrelated Chinese word pairs, while during non-semantic encoding task they were asked to judge whether the two Chinese word pairs had the same morphological structure or not. Light intensity of two wavelengths (760 nm and 850 nm) diffused through skull and left prefrontal lobe were real-time recorded and used to reconstruct the brain activation image during the experiment.

RESULT

With the fNIRI, significant activations were observed in the left inferior prefrontal cortex (Brodmann' areas 45 and 47) during the two tasks, but the evoked activations were more significant for semantic than non-semantic task. These observations were consistent with the results reported by others with functional megnetic resonance imaging (fMRI) and positron-emission tomography PET.

CONCLUSION

The results suggest that fNIRI provides an important, non-invasive way to map the prefrontal activation during cognitive tasks.