Br2 elimination in 248-nm photolysis of CF2Br2 probed by using cavity ring-down absorption spectroscopy

By using cavity ring-down absorption spectroscopy technique, we have observed the channel of Br2 molecular elimination following photodissociation of CF2Br2 at 248 nm. A tunable laser beam, which is crossed perpendicular to the photolyzing laser beam in a ring-down cell, is used to probe the Br2 fragment in the B 3Piou+-X1Sigmag+ transition. The vibrational population is obtained in a nascent state, despite ring-down time as long as 500-1000 ns. The population ratio of Br2(v=1)/Br2(v=0) is determined to be 0.4+/-0.2, slightly larger than the value of 0.22 evaluated by Boltzmann distribution at room temperature. The quantum yield of the Br2 elimination reaction is also measured to be 0.04+/-0.01. This work provides direct evidence to support molecular elimination occurring in the CF2Br2 photodissociation and proposes a plausible pathway with the aid of ab initio potential-energy calculations. CF2Br2 is excited probably to the 1B1 and 3B2 states at 248 nm. As the C-Br bond is elongated upon excitation, the coupling of the 1A'(1B1) state to the high vibrational levels of the ground state X 1A'(1A1) may be enhanced to facilitate the process of internal conversion. After transition, the highly vibrationally excited CF2Br2 feasibly surpasses a transition barrier prior to decomposition. According to the ab initio calculations, the transition state structure tends to correlate with the intermediate state CF2Br+Br(CF2Br...Br) and the products CF2+Br2. A sequential photodissociation pathway is thus favored. That is, a single C-Br bond breaks, and then the free-Br atom moves to form a Br-Br bond, followed by the Br2 elimination. The formed Br-Br bond distance in the transition state tends to approach equilibrium such that the Br2 fragment may be populated in cold vibrational distribution. Observation of a small vibrational population ratio of Br2(v=1)Br2(v=0) agrees with the proposed mechanism.

Influence of vibrational excitation on the nonadiabatic reactions of metal atoms with H2

The reactions of alkaline earth metal atoms, Mg(3s3p 1P1) and Ca(4s4p 1P1), with H2(v = 1, j) are studied using a pump-probe technique combined with stimulated Raman pumping and coherent anti-Stokes Raman spectroscopy. For the Ca(4 1P1) case, the energy deposited in the v = 1 level enlarges the H2 bond distance to help facilitate the reaction without opening an additional pathway. For the Mg(3 1P1) case, the vibrational excitation of H2 leads to enhancement of the low rotational component of the rotational distribution and the MgH(v = 0)/MgH(v = 1) ratio. These results can be predicted with quasi-classical trajectory calculations and interpreted with a kinematic collision model.

Continuum and discrete pulsed cavity ring down laser absorption spectra of Br2 vapor

The absorption cross-sections at room temperature are reported for the first time, of Br2 vapor in overlapping bound-free and bound-bound transition of A(3)pi1u <-- Xsigma(g)+, X(1)pi1u <-- X(1)sigma(g)+ and B(3)pi0u <-- X(1)sigma(g)+, using cavity ring down spectroscopy (CRDS) technique. We reported here, the A(3)pi1u <-- X(1)sigma(g)+, transition is included along with the two stronger X(1)pi1u <-- X(1)sigma(g)+ and B(3)pi0u <-- X(1)sigma(g) transitions of Br2. We obtained discrete absorption cross-section in the rotational structure, the continuum absorption cross-sections, and were also able to measure the absorption cross-section in separate contribution of A(3)pi1u <-- X(1)sigma(g)+, (1)pi1u <-- X(1)sigma(g)+, and B(3)pi0u <-- X(1)sigma(g)+ transitions using CRDS method to use quantum yield of Br*((2)P(1/2)). We obtained absorption cross-section order 10(-19) cm2 and detection 10(13) molecule cm(-3) (1 mTorr) of Br2. The absorption cross-sections are increasing with increasing excitation energy in the wavelength region 510-535 nm.

The effect of etanercept on anti-cyclic citrullinated peptide antibodies and rheumatoid factor in patients with rheumatoid arthritis

OBJECTIVE

To evaluate the changes in anti-cyclic citrullinated peptide antibodies (anti-CCP) and rheumatoid factor (RF) following etanercept treatment in patients with rheumatoid arthritis.

METHODS

The study included 90 patients with rheumatoid arthritis who failed treatment with disease modifying antirheumatic drugs (DMARDs). All patients were allowed to continue treatment with DMARDs; 52 of them received etanercept as a twice weekly 25 mg subcutaneous injection for three months, and the others did not. Serum samples were collected at baseline and one month intervals during the treatment course. The serum levels of anti-CCP and RF were tested by enzyme linked immunosorbent assay and nephelometry, respectively.

RESULTS

At baseline, 45 of the 52 etanercept treated patients (86.5%) and 32 of the 38 controls (84.2%) were positive for anti-CCP. Tests for RF were positive in 78.9% and 84.2% of patients with or without etanercept treatment, respectively. The serum levels of anti-CCP and RF decreased significantly after a three month etanercept treatment (p = 0.007 and p = 0.006, respectively). The average decrease from baseline calculated for each individual patient in the etanercept treated group was 31.3% for anti-CCP and 36% for RF. The variation in anti-CCP was positively correlated with the variation in disease activity, swollen and tender joint counts, RF, and C reactive protein.

CONCLUSIONS

Etanercept combined with DMARDs leads to a much greater decrease than DMARDs alone in the serum levels of anti-CCP and RF in rheumatoid arthritis, compatible with a reduction in clinical disease activity.

Study of undifferentiated spondyloarthropathy among first-degree relatives of ankylosing spondylitis probands

OBJECTIVE

To estimate in a Chinese population the prevalence of undifferentiated spondyloarthropathy (USpA) among first-degree relatives (FDRs) of ankylosing spondylitis (AS) probands, and to compare the clinical features of familial USpA with those of sporadic USpA.

METHODS

The FDRs of two separate cohorts of consecutive AS probands were evaluated for the prevalence of USpA, using the Modified New York criteria and the European Spondylitis Study Group criteria for AS and SpA, respectively. Sporadic USpA and FDRs of non-SpA rheumatic patient probands served as separate controls.

RESULTS

Among the 301 FDRs of 102 AS probands, 7.0% were USpA. This was 1000 times higher than the 147 FDRs of 40 non-SpA probands (P = 0.00230). Within the AS families, USpA was less male-dominated than AS (33.3 vs 72.5%) (P = 0.006). The only feature distinguishing familial from sporadic USpA was that the percentages of HLA B27 were 100 and 50%, respectively (P<0.001).

CONCLUSION

USpA and AS coexist in the same Chinese families, both being predisposed by HLA B27. In these families, a female gender favours the development of USpA rather than AS. A significant subset of sporadic USpA (HLA B27-negative group) has a different genetic predisposition compared with familial USpA.

Reaction pathway for the nonadiabatic reaction of Ca(4s3d 1D)+H2-->CaH(X 2Sigma+)+H

The reaction pathway and the nascent CaH product distribution in the reaction Ca(4s3d (1)D)+H(2)-->CaH(X (2)Sigma(+))+H are obtained using a pump-probe technique. The Ca atom is first prepared in the 3 (1)D state by a two-photon absorption, and then in brief time delay the laser-induced fluorescence of the reaction product CaH is monitored. The CaH(v=0,1) distributions appear to be single peaked, as characterized by Boltzmann rotational temperature of 807+/-38 K (v=0) and 684+/-77 K (v=1). The vibrational population ratio of CaH(v=0)/CaH(v=1) is determined to be 3.3+/-0.1, while the v=2 population is not detectable. The fractions of the available energy partitioning into rotation, vibration, and translation are estimated to be 0.36+/-0.05, 0.28+/-0.04, and 0.36+/-0.05, respectively. With the aid of the potential energy surfaces calculations, the current reaction should favor a near C(2v) collision configuration. The temperature dependence measurement yields a positive slope, indicative of the reaction occurrence without any potential barrier. The colliding species are anticipated to follow an attractive 1B(2) (or 2A') surface and then transit nonadiabatically to the reactive ground state surface.

Causes and consequences of high osmotic potentials in epiphytic higher plants

Past reports of the water relations of epiphytes, particularly bromeliads, indicate that tissue osmotic potentials in these tropical and subtropical plants are very high (close to zero) and are similar to values for aquatic plants. This is puzzling because several ecophysiological studies have revealed a high degree of drought stress tolerance in some of these epiphytes. The goal of this study was two-fold: (1) to increase the number of epiphytic taxa sampled for tissue osmotic potentials; and (2) to explain the apparent discrepancy in the significance of the tissue water relations and tolerance of drought stress in epiphytes. Tissue osmotic potentials of 30 species of epiphytic ferns, lycophytes, and orchids were measured in a subtropical rain forest in northeastern Taiwan. Nearly all values were less negative than -1.0 MPa, in line with all previous data for epiphytes. It is argued that such high osmotic potentials, indicative of low solute concentrations, are the result of environmental constraints of the epiphytic habitat on productivity of these plants, and that low rates of photosynthesis and transpiration delay the onset of turgor loss in the tissues of epiphytes such that they appear to be very drought-stress tolerant. Maintenance of photosynthetic activity long into drought periods is ascribed to low rates of transpiration and, hence, delayed tissue desiccation, and hydration of the photosynthetic tissue at the expense of water from the water-storage parenchyma.

A3Pi1u<--X1Sigmag+ laser photoacoustic spectroscopy of Br2 vapor in the extreme red wavelength region 665-720 nm

The A3Pi1u<--X1Sigmag+ photoacoustic spectrum of Br2 vapor has been studied and vibronic analysis performed using earlier data available for this system of bands from optical spectroscopy in the region 665-720 nm. The vibronic levels involved in these transitions are 4< or =v'< or =21 and 1< or =v''< or =4. The relative photoacoustic intensities of the vibronic bands have been used in estimating the non-radiative relaxation rate from vibrational levels of A3Pi(1u) state. The non-radiative relaxation is found to be a nonlinear function of the upper state vibrational quantum number. The radiative rate constants for the A3Pi(1u) state vibrational levels have been compared with the corresponding non-radiative constants obtained from present work. Non-radiative decay rate constants for the vibrational levels of A3Pi(1u) state have been experimentally determined for the first time from photoacoustic spectrum of Br2 vapor in the extreme red region.

Reaction pathway and potential barrier for the CaH product in the reaction of Ca(4s4p 1P1)+H2→CaH(X 2Σ+)+H

The nascent CaH product in the reaction Ca(4s4p1P1) + H2 --> CaH(X2Sigma+) + H is obtained using a pump-probe technique. The CaH(v = 0,1) distributions, with a population ratio of CaH(v = 0)/CaH(v = 1) = 2.7+/-0.2, may be characterized by low Boltzmann rotational temperature. According to Arrhenius theory, the temperature dependence measurement yields a potential barrier of 3820+/-480 cm(-1) for the current reaction. As a result of the potential energy surfaces (PES) calculations, the reaction pathway favors a Ca insertion into the H2 bond along a (near) C2v geometric approach. As the H2 bond is elongated, the configurational mixing between the orbital components of the 4p and nearby low-lying 3d state with the same symmetry makes significant the nonadiabatic transition between the 5A' and 2A' surface in the repulsive limbs. Therefore, the collision species are anticipated to track along the 5A' surface, then undergo nonadiabatic transition to the inner limb of the 2A' surface, and finally cross to the reactive 1A' surface. The observed energy barrier probably accounts for the energy requirement to surmount the repulsive hill in the entrance. The findings of the nascent CaH product distributions may be reasonably interpreted from the nature of the intermediate structure and lifetime after the 2A'-1A' surface transition. The distinct product distributions between the Ca(4 1P1) and Mg(3 1P1) reactions with H2 may also be realized with the aid of the PES calculations.

Protective effects of alpha-tocopherol and mannitol in both circulatory shock and cerebral ischaemia injury in rat heatstroke

1. There is evidence that hydroxyl radicals are accumulated and oxidative stress is produced in multiple organs, including the brain, of rats with heat stroke. Herein, we investigated the effect on heat stroke-induced circulatory shock and cerebral ischaemic injury of two free radical scavengers, namely mannitol and alpha-tocopherol. 2. Urethane-anaesthetized rats were exposed to heat stress (ambient temperature 42 degrees C) to induce heat stroke. Control rats were exposed to 24 degrees C. Mean arterial pressure and cerebral blood flow after the onset of heat stroke were significantly lower in heat stroke rats than in control rats. However, cerebral free radicals, lipid peroxidation and the neuronal damage score were greater in heat stroke rats compared with control rats. Similarly, plasma cytokines, including tumour necrosis factor-alpha, interleukin (IL)-1beta and IL-6, were significantly higher in heat stroke rats compared with their normothermic controls. 3. Pretreatment with alpha-tocopherol (20 mg/kg, i.v.) or mannitol (10%, i.v.) 30 min before the onset of heat exposure significantly attenuated heat stroke-induced arterial hypotension, cerebral ischaemia and neuronal damage, the increased free radical formation and lipid peroxidation in the brain and the increased plasma levels of cytokines. Pretreatment with alpha-tocopherol or mannitol resulted in a prolongation of survival time in heat stroke. 4. These results demonstrate that although pretreatment with alpha-tocopherol and mannitol does not prevent the heat stroke syndrome entirely, an attenuation of the syndrome is observed.

Two-dimensional correlation analysis for a kinetic model of consecutive reactions

We have systematically studied a kinetic scheme of consecutive reactions by using generalized two-dimensional (2D) correlation analysis as reported by Noda. The correlations between reactant-intermediate, intermediate-product, and reactant-product pairs are analyzed with the related rate constants and absorption coefficients. When the reference spectrum is set at zero, the synchronous and asynchronous correlation spectra for the kinetic model are almost free from the influence of poor quality signals. If an appropriate reference spectrum is selected, the intermediate can be feasibly distinguished from other species involved in the reaction. A ratio of asynchronous to synchronous correlation intensity yields a coherence spectrum, which is characterized by different plateau-type peak intensities. When a steady-state condition fits the kinetic model, the peak summation of reactant-intermediate and intermediate-product correlation will approach the intensity of the reactant-product correlation. The coherence spectrum is useful for pattern recognition of the reaction scheme and also provides an effective way to identify the location and the extent of spectral overlap between two peaks.

Two-dimensional correlation analysis in application to a kinetic model of parallel reactions

By applying generalized two-dimensional (2D) correlation analysis as reported by Noda, we have systematically studied a kinetic model of parallel reactions. Given the related rate constants and absorption coefficients, the correlation between reactant and products are analyzed. The reactant-reactant, reactant-product, and product-product pairs are found to be synchronously correlated, and their intensities increase with increase of the rate constant and the absorption coefficient. On the other hand, only the reactant-product pairs show in the asynchronous spectra. Their intensities also depend proportionally on the rate constant and the absorption coefficient. The influence of signal-to-noise ratio (S/N) and overlapped spectra are further discussed. The resulting synchronous and asynchronous correlation spectra for the kinetic model appear to be weakly influenced by poor quality of the signal when the reference spectrum is set at zero. The ratio of asynchronous to synchronous correlation intensity yields a coherence spectrum. This spectrum remains a constant intensity for all the correlated peaks, being free from the influence of rate constant and absorption coefficient as well as being weakly disturbed by a small S/N ratio. It also provides a way to evaluate the extent of spectral overlap between two peaks. The coherence spectrum is useful to characterize the type of parallel reactions.

Enteropathogenic Escherichia coli and ulcerative colitis in cotton-top tamarins (Saguinus oedipus)

The cotton-top tamarin (CTT; Saguinus oedipus) is an endangered New World primate that develops a highly prevalent idiopathic colitis resembling human ulcerative colitis. This study found that enteropathogenic Escherichia coli (EPEC) caused acute colitis in CTTs, which was associated with ulcerative colitis. EPEC clinical isolates revealed localized adherence patterns by HEp-2 assay and were devoid of Shiga-toxin production. Sequencing of the eae gene (GenBank accession no. AF319597) revealed 99.2% identity to sequences of human isolates (GenBank AF116899) and corresponded to the epsilon intimin gene subtype. Detection of intimin sequences by polymerase chain reaction on primary fecal cultures indicated widespread EPEC infection in the CTT colony. Prospective analysis revealed that animals with fecal cultures positive for intimin sequences had a higher frequency of active colitis (75.0% vs. 27.2%; P<.005, chi(2) test) and higher histological scores of colonic inflammation (0.875 vs. 0.455, respectively; P<.05, Mann-Whitney rank sum test).

The hetero Diels-Alder reactions of masked o-benzoquinones with nitroso compounds

The first examples of hetero Diels-Alder reaction of masked o-benzoquinones with nitroso dienophiles leading to novel and highly functionalized heterocycles, which are potential intermediates for nitrogenous natural products are reported.

Induction of disseminated Mycobacterium avium in simian AIDS is dependent upon simian immunodeficiency virus strain and defective granuloma formation

Mycobacterium avium complex (MAC) is the most common disseminated bacterial disease in patients infected by the human immunodeficiency virus. Although murine models of disseminated MAC exist, they are primarily based on underlying genetic susceptibilities and cannot adequately address the complex interactions that occur between host, mycobacteria, and immunosuppressive lentivirus. To address this problem we have developed an experimental system to co-inoculate rhesus macaques with the simian immunodeficiency virus (SIV) and a clinical M. avium isolate that results in a disease virtually identical to that observed in human cases. Using this experimental system we have found that the development of disseminated MAC is dependent on viral strain. Animals co-infected with SIVmac251 and M. avium developed progressive disease, whereas control animals and animals inoculated with closely related viruses (SIVmac239 and SIVmac239MER) developed self-limiting infections. The ability of animals infected with SIVmac239 or SIVmac239MER to eliminate mycobacterial disease was independent of viral load and CD4 T-cell number but was correlated with the size and composition of microgranulomas. This work establishes a novel primate model of disseminated MAC in the context of immunosuppressive lentiviral infection and advances our understanding of why human immunodeficiency virus-infected patients are remarkably sensitive to the development of mycobacterial disease.

Laser-enhanced ionization and laser-induced atomic fluorescence as element-specific detection methods for gas chromatography. Application to organotin analysis

We have demonstrated that flame laser-enhanced ionization (LEI) and flame laser-induced atomic fluorescence (LIAF) techniques can be used as, alternative sensitive detectors for gas chromatographic (GC) analysis of organotin compounds. These two element-specific detection methods are free from interferences from the organic solvent. Two types of LEI schemes for Sn detection are employed. For the two-step LEI scheme (TLEI), the tin atoms in the flame were stepwise excited and then ionized collisionally. In contrast, in detection with the single-step LEI scheme (SLEI), only one dye laser is used. For the analysis of tetramethyltin and tetraethyltin, the GC-TLEI, GC-SLEI, and GC-LIAF systems yield linear dynamic ranges of 0.015-400, 0.39-600 and 0.5-600 ng, respectively. The corresponding detection limits reach 0.15, 3.9 and 5.0 mg/l, with absolute quantities corresponding to 15, 390 and 500 pg, respectively, for an injection volume of 0.1 microl. These detection methods prove to be more sensitive and selective than the conventional flame ionization detection, which achieves absolute detection limits of 800 and 1667 pg for tetraethyltin and tetramethyltin, respectively, under identical GC conditions.

Effectiveness of postoperative adjuvant therapy in improving reproductive outcome of endometriosis-associated infertility

BACKGROUND AND PURPOSE

Treatment of endometriosis-associated infertility has not yet become standardized. Various protocols including surgical treatment, medical therapy, and a combination of both have been suggested but their use remains controversial. The objective of the present study was to determine whether postoperative adjuvant therapy for endometriosis is effective in improving reproductive outcome.

METHODS

Medical records of infertile patients with newly diagnosed endometriosis treated in a university teaching hospital during a 50-month period were reviewed. After exclusion of patients with other major infertility factors, a total of 209 patients were included in the retrospective analysis. These patients were divided into those receiving (n = 78) or not receiving (n = 131) peri- or postoperative adjuvant medical therapy. The adjuvant therapies included danazol (n = 62), gonadotropin releasing hormone analogues (n = 11), progestins (n = 3), oral contraceptives (n = 1), and mixed treatment (n = 1).

RESULTS

The pregnancy rate was lower in those receiving adjuvant therapy, although this result was not significant (32.1% vs 45.8%; p = 0.05). When patients using postoperative danazol therapy were considered alone, the pregnancy rate in patients receiving adjuvant therapy was significantly lower than that in patients not receiving it (p = 0.047). When the stage of endometriosis was considered, the pregnancy rate in patients receiving adjuvant therapy was again lower than in those not receiving it in patients with minimal or mild endometriosis (42.9% vs 60%; p = 0.043). However, in patients with moderate or severe endometriosis, the pregnancy rate was not different in the two groups (31% vs 36%; p = 0.56). Postoperative assisted reproductive techniques (ART) including controlled ovarian hyperstimulation/intrauterine insemination (COH/IUI) and in vitro fertilization (IVF) were effective in improving the pregnancy rates for all patients (53.9% with ART vs 33.1% without; p = 0.003) and for patients with advanced endometriosis (47.7% with ART vs 27.2% without; p = 0.016).

CONCLUSIONS

Our results suggest that postoperative adjuvant therapy is ineffective in improving reproductive outcome in patients with either early (minimal or mild) or advanced (moderate and severe) endometriosis. This finding suggests that if fertility is the goal of treatment, adjuvant therapy may be unnecessary after surgery. In contrast, our data suggest that empirical ART, including COH/IUI or IVF, may be a better alternative to improve the pregnancy outcome after surgery.

Gender differences in the relationships of serum uric acid with fasting serum insulin and plasma glucose in patients without diabetes

OBJECTIVE

To explore gender differences in the relationship of serum uric acid levels with fasting serum insulin and fasting plasma glucose concentrations among an adult Chinese nondiabetic population in Kinmen, Taiwan.

METHODS

A total of 7,483 nondiabetic subjects (4,265 women, 3,218 men, aged 30 to 89 years) were involved in a community based epidemiologic study. Those with known or newly diagnosed diabetes were excluded. Overnight fasting blood samples were drawn for serum uric acid, glucose, insulin, lipid, and other biochemical measurements. Demographic and clinical variables including body mass index (weight/height2), waist-to-hip ratio, and blood pressure were measured and documented during face-to-face interviews with structured questionnaires.

RESULTS

Stratified analyses revealed that (1) serum uric acid levels were positively associated with hyperinsulinemia and HOMA-insulin resistance in both men and women after adjusting for hypertriglyceridemia, hypertension, obesity, and plasma glucose levels; and (2) serum uric acid levels were more strongly associated with hyperinsulinemia and plasma glucose levels in women than in men. CONCLUSION; Hyperuricemia was positively associated with hyperinsulinemia among patients of both sexes without diabetes. Elevated levels of uric acid should alert physicians to the possibility of insulin resistance. The serum uric acid level was associated with insulin resistance and plasma glucose levels more strongly in females than in males in our study population.

Progression after release of obstructive nephropathy

Progressive glomerular and tubulointerstitial fibrosis develop in 1-year-old rats even after relief (R) of unilateral ureteral obstruction (UUO) at 5 days of age. The present study investigated whether a progressive renal injury model of UUO could be achieved after reversal of UUO (RUUO) in adult instead of neonatal rats. The potential for alpha-tocopherol modulation of mRNA for the fibrogenic cytokine, transforming growth factor-beta1 (TGFbeta1), apoptosis (TUNEL assay), and the presence of the stress protein, heat shock protein-70 (HSP-70), was also studied in this post-obstructive model. Male Sprague-Dawley rats weighing 125-150 g were randomly assigned to groups of 4 animals each for durations of 7 or 14 days of alpha-tocopherol supplementation after RUUO. The groups included: (i) sham, regular chow; (ii) RUUO, regular chow; (iii) RUUO, contralateral nephrectomy (NX); and (iv) RUUO, NX plus alpha-tocopherol supplementation. We found a significant increase in the ratio of kidney weight/body weight in the RUUO+NX group at 14 days compared with the sham and RUUO groups. This rise in the RUUO+NX group was significantly reduced after 14 days of alpha-tocopherol administration. The elevated level of kidney TGFbeta1 mRNA in the RUUO+NX group was only partially reduced at 7 days. But at 14 days this became significantly reduced with the continued alpha-tocopherol treatment. The HSP-70 staining and the apoptosis of the kidney showed results parallel to those of TGFbeta mRNA at 14 days. To separate the effects of hypertrophy after unilateral NX from the RUUO studies, we carried out a second experiment in control animals subjected to NX, with and without alpha-tocopherol supplementation. Fourteen days after NX, the apoptosis and TGFbeta1 mRNA showed no significant differences from the control animals. Our data suggest that a model of progressive renal injury in RUUO can be established in adult rats. After contralateral NX, the progressive injury is evidenced by the increase in the ratio of kidney weight/total body weight, the apoptotic counts, as well as fibrogenic cytokine TGFbeta1 mRNA in the post-obstructed kidney. Finally, our data also support the concept that alpha-tocopherol is renal protective, as judged by TGFbeta1 mRNA, apoptosis, and HSP-70 staining, even in the progressive disease process of the post-obstructed model.

Identification of enteropathogenic Escherichia coli in simian immunodeficiency virus-infected infant and adult rhesus macaques

Enteropathogenic Escherichia coli (EPEC) was recognized as a common opportunistic pathogen of simian immunodeficiency virus-infected rhesus macaques (Macaca mulatta) with AIDS. Retrospective analysis revealed that 27 of 96 (28.1%) animals with AIDS had features of EPEC infection, and EPEC was the most frequent pathogen of the gastrointestinal tract identified morphologically. In 7.3% of animals dying with AIDS, EPEC represented the sole opportunistic agent of the gastrointestinal tract at death. In 20.8% of cases, it was seen in combination with one or more gastrointestinal pathogens, including Cryptosporidium parvum, Enterocytozoon bieneusi, Mycobacterium avium, Entamoeba histolytica, Balantidium coli, Strongyloides stercoralis, cytomegalovirus, and adenovirus. Clinically, infection was associated with persistent diarrhea and wasting and was more frequent in animals that died at under 1 year of age (P < 0.001, Fisher exact test). The organism was associated with the characteristic attaching and effacing lesion in colonic tissue sections and produced a focal adherence pattern on a HEp-2 assay but was negative for Shiga toxin production as assessed by PCR and a HeLa cell cytotoxicity assay. A 2.6-kb fragment encompassing the intimin gene was amplified and sequenced and revealed 99.2% identity to sequences obtained from human isolates (GenBank AF116899) corresponding to the epsilon intimin subtype. Further investigations with rhesus macaques may offer opportunities to study the impact of EPEC on AIDS pathogenesis and gastrointestinal dysfunction.

Dietary factors associated with physician-diagnosed asthma and allergic rhinitis in teenagers: analyses of the first Nutrition and Health Survey in Taiwan

The occurrence of asthma and allergy are related to lifestyle factors, and dietary pattern may be one of the contributing factors. To examine the possible association between dietary intake and the prevalence of asthma and allergic rhinitis in teenagers. In a population-based cross-sectional survey, the relationship was sought between food frequency and physician-diagnosed asthma and allergic rhinitis in 1166 adolescents aged 13-17. The prevalence was 4.0% for asthma and 12.4% for rhinitis. Living in an urbanized area was a significant predictor of asthma and rhinitis. In univariate analysis, higher frequencies of oily fish, butcher's meat, liver and deep-fried foods were associated with asthma. Relevant food frequency variables were dichotomized at the 75th percentile for multivariate logistic regression analysis, which included adjustment for two levels of urbanization. Asthma was associated with intakes of liver (OR = 2.32, 95%CI 1.11-4.80), deep-fried foods (OR = 2.13, 95%CI 1.06-4.30) and butcher's meat (OR 1.84, 95%CI 0.89-3.80). In a similar analysis, allergic rhinitis was associated with liver (OR = 1.67, 95%CI 1.06-2.63). No protective effect was demonstrated for any of the food items examined. Protein-rich and fat-rich foods of animal origin were associated with a higher prevalence of asthma in teenagers.

Effects of task goal and personal preference on seated reaching kinematics after stroke

BACKGROUND AND PURPOSE

Current theories of motor control in rehabilitation focus on how the nervous system responds to many types of external and internal constraints to execute motor behavior to accomplish a task. However, the dynamic interplay between these 2 constraints remains unclear. This study examined the impact of some aspects of internal and external constraints on motor performance in persons with stroke.

METHODS

Twenty-seven persons with stroke used the uninvolved arms to perform an upper-extremity reaching task under 4 experimental conditions, formed by the crossing of functional goals and personal preferences. For the higher level of a functional goal, subjects took a drink from a can of beverage. For the lower level of a functional goal, subjects brought the can to the mouth without drinking. The level of personal preferences was determined, by interview, by the degree of predilection for particular beverages.

RESULTS

Significant and large effects of functional goals and personal preference were found in the variables of movement time and reaction time. However, the data trend of the 4 testing conditions varied according to presence of visuospatial neglect and side of lesion.

CONCLUSIONS

Offering choices for the treatment activities and incorporating functional goals to therapeutic tasks might enhance response rate or movement efficiency, depending on the side of the lesion and presence of visuospatial neglect. The findings suggest that the consideration of the neglect phenomenon is a necessity when rehabilitative treatment planning incorporates constraint factors.

Chlorination of drinking water and sex ratio at birth in Taiwan

Chlorination has been the major strategy for disinfecting drinking water in Taiwan. The objective of the present study was to determine whether the chlorination of drinking water was associated with abnormal sex ratios, an indicator of exposure to pollutants. A "chlorinating municipality" (CHM) was defined as one in which more than 90% of the municipality population was served with chlorinated water. A "nonchlorinating municipality" (NCHM) was one in which less than 5% of the municipality population was served with chlorinated water. The results of this study found no association between the use of chlorinated drinking water and abnormal sex ratios at birth in Taiwan. The imbibing of chlorinated water may not reflect contaminant exposure using sex ratio as a biomonitor.

A small-molecule, tight-binding inhibitor of the integrin alpha(4)beta(1) blocks antigen-induced airway responses and inflammation in experimental asthma in sheep

The leukocyte integrin very late antigen-4 (alpha(4)beta(1), CD49d/CD29) is an adhesion receptor that plays an important role in allergic inflammation and contributes to antigen-induced late responses (LAR) and airway hyperresponsiveness (AHR). In this study, we show that single doses of a new small-molecule, tight-binding inhibitor of alpha(4), BIO-1211, whether given by aerosol or intravenously, either before or 1.5 h after antigen challenge blocks allergen- induced LAR and post-antigen-induced AHR in allergic sheep. Multiple treatments with doses of BIO-1211 that were ineffective when given singly, were protective. BIO-1211 also provided dose-dependent inhibition of the early airway response (EAR) to antigen. In conjunction with the functional protection against the antigen-induced LAR and AHR, sheep treated with BIO-1211 before challenge showed significantly reduced: (1) numbers of eosinophils in bronchoalveolar lavage (BAL), (2) BAL levels of the inflammatory marker tissue kallikrein, and (3) numbers of inflammatory cells (lymphocytes, eosinophils, metachromatic staining cells, and neutrophils) in bronchial biopsies obtained after challenge when compared with corresponding biopsies after vehicle treatment. More importantly, we show for the first time that an inhibitor of alpha(4) was able to reverse post-antigen-induced AHR, thereby decreasing the time of recovery from the normal period of > 9 d to 3 d. Our results show that effective inhibition of antigen-induced airway responses can be achieved with single doses of a potent small-molecule inhibitor of alpha(4) and that such agents may be used therapeutically, as well as prophylactically, to alleviate allergen- induced inflammatory events. These data provide further support and extend the evidence for the role of alpha(4) integrins in the pathophysiologic events that follow airway antigen challenge.

Association between chlorination of drinking water and adverse pregnancy outcome in Taiwan

Chlorination has been the major means of disinfecting drinking water in Taiwan. The use of chlorinated water has been hypothesized to lead to several adverse birth outcomes, including low birth weight and preterm delivery. We performed a study to examine the relationship between the use of chlorinated water and adverse birth outcomes in Taiwan. The study areas included 14 chlorinating municipalities (CHMs), which were defined as municipalities in which > 90% of the municipal population was served by chlorinated water, and 14 matched nonchlorinating municipalities (NCHMs), defined as municipalities in which < 5% of the municipal population is served by chlorinated water. The CHMs and NCHMs were similar to one another in terms of level of urbanization and sociodemographic characteristics. The study population comprised 18,025 women residing in the 28 municipalities who had a first parity singleton birth between 1 January 1994 and 31 December 1996 and for which complete information on maternal age, education, gestational age, birth weight, and sex of the baby were available. The results of our study suggest that there was no association between consumption of chlorinated drinking water and the risk of low birth weight.

Different association of hypertension and insulin-related metabolic syndrome between men and women in 8437 nondiabetic Chinese

Insulin resistance may cause a metabolic syndrome but whether insulin resistance causes hypertension is very controversial. Furthermore, it remains unclear whether the link between the insulin-resistance-related metabolic syndrome and hypertension is different between men and women. We examined fasting insulin, glucose, triglyceride and high-density lipoprotein (HDL)-cholesterol levels, systolic blood pressure, body mass index, and waist-to-hip ratio in a dataset from 8437 nondiabetic residents (age range, 30 to 89 years) in Kinmen. Factor analysis, a multivariate correlation statistical technique, was used to investigate the clustering and interdependence of these risk variables. Factor analysis identified two factors for men (n = 3659) and three factors for women (n = 4778, respectively. In men, a cluster of insulin, triglyceride, HDL-cholesterol, body mass index, and waist-to-hip ratio (metabolic syndrome) accounted for 29.7%, and a cluster of systolic blood pressure and glucose (hyperglycemia plus hypertension) accounted for 18.1% of the total variance in all variables considered. In women, a cluster of insulin, triglyceride, body mass index, waist-to-hip ratio, and systolic blood pressure (metabolic syndrome plus hypertension) accounted for 29.4%, a cluster of systolic blood pressure, glucose, and triglyceride (hyperglycemia plus hypertension plus dyslipidemia) accounted for 14.0%, and a cluster of triglyceride and HDL-cholesterol (dyslipidemia) accounted for 16.2% of the total variance. In conclusion, a distinct insulin-resistance-related metabolic syndrome characterized by hyperinsulinemia, dyslipidemia, and obesity was observed for both men and women in this Chinese population. However, hypertension was linked to the metabolic syndrome in women only.

The interaction between uric acid level and other risk factors on the development of gout among asymptomatic hyperuricemic men in a prospective study

OBJECTIVE

To investigate the incidence of gout and the interaction between uric acid level and other risk factors in the development of gout.

METHODS

Two hundred twenty-three asymptomatic hyperuricemic men initially studied in 1991-92 were reassessed in 1996-97. Gout was clinically diagnosed by a senior rheumatologist based on history and physical according to the clinical criteria of Wallace. Basic demographic and lifestyle variables as well as biochemical data were collected in both baseline and followup periods. Both the stability analysis and the analysis of repeated relationships were applied.

RESULTS

The 5-year cumulative incidence of gout was 18.83% (42/223). The risk factors for gout based on the analysis of repeated relationships were uric acid level, alcohol consumption, use of diuretics, and obesity. The only predictor of gout at baseline was uric acid level. After adjusting for baseline uric acid level, followup uric acid increase, persistent alcohol consumption, use of diuretics in the followup period, and body mass index increase were independent predictors for gout among asymptomatic hyperuricemic men. Excessive alcohol consumption, particularly if occasional, was the most important factor in the development of gout, even when the concentration of uric acid level was below 8 mg/dl.

CONCLUSION

Uric acid level is the key factor for prevention of gout and needs constant monitoring. Other contributing or possible etiologic factors such as alcohol consumption, diuretics use, and excess weight gain carry an increased risk of gout attack among patients with hyperuricemia.

Community based epidemiological study on hyperuricemia and gout in Kin-Hu, Kinmen

OBJECTIVE

This is a population survey conducted in 1991-92 among residents aged > or =30 years in Kin-Hu, Kinmen, with a 77.7% response rate to study the prevalence of hyperuricemia and hyperuricemia associated gout. A stratified analysis based on sex and age was used to assess the interaction and analyze the associated risk factors for hyperuricemia and gout.

METHODS

Hyperuricemia was defined as uric acid > or =7.0 mg/dl for men and > or =6.0 mg/dl for women. Gout was clinically diagnosed by a senior rheumatologist based on patient's history and examination according to the clinical criteria of Wallace. Basic demographic and lifestyle variables as well as biochemical data were collected.

RESULTS

The prevalence of hyperuricemia was 25.8% (391/1515) in men and 15.0% (250/1670) in women. The prevalence of gout among hyperuricemic subjects was 11.5% for men and 3% for women. According to age spectrum, the risk factor for hyperuricemia was hyperlipidemia in young adults (30-39 yrs); lifestyle and some clinical syndromes played a significant role in middle aged persons (40-59 yrs). The different risk factors between the sexes in middle age were alcohol consumption effect in men and menopause effect in women. Impaired renal function and use of diuretics became the important factors in the elderly (> or =60 yrs). The risk factors for gout among either the general population or subjects with hyperuricemia were concentration of serum uric acid, alcohol consumption, and central obesity.

CONCLUSION

Risk factors for hyperuricemia tended to be different with respect to sex and age. Alcohol consumption and central obesity were independent predictors of gout among hyperuricemic subjects irrespective of uric acid level.

Hantavirus infection in Taiwan: the experience of a geographically unique area

Hantaviruses are rodent-borne viruses, and they, mainly the Hantaan (HTN) serotype, are the causative agents of a group of febrile nephropathies known as "hemorrhagic fever with renal syndrome (HFRS). " Despite the fact that HFRS is frequently reported in China, with an annual incidence of 50,000-100,000 cases, one puzzling observation that no local case of HFRS has been confirmed in Taiwan has yet to be explained. We hypothesized that the hantavirus strain prevailing in Taiwan mainly belongs to the mild strain, the Seoul (SEO) strain, and the absence of severe disease was related to the absence of HTN. To test these hypotheses, this epidemiologic study was performed, including a seroprevalence survey and phylogenetic analysis on hantavirus isolated from the rodent population trapped in major seaports, rural, and mountainous areas of Taiwan. This study also included rodents and viruses from two isolated islands, Kinmen and Matzu, which are geographically adjacent to the east coast of mainland China. There were a total of 5,461 rodents of 16 species captured, and R. norvegicus was the most common species, with an antibody prevalence much higher in international seaports (20%) than in rural regions (approximately 5%) and intermediate in some domestic seaports. By reverse transcriptase polymerase chain reaction (RT-PCR), 33.9% of the seropositive R. norvegicus were found to have amplifiable hantavirus sequences in their lung tissues, and subsequent phylogenetic analyses indicated that almost all hantavirus in Taiwan was most closely related to the prototype SEO strain, and no HTN strain was recovered from any rodent species indigenous to Taiwan. The seroprevalence of SEO infection in R. norvegicus on Kinmen and Matzu was also different from that in southern provinces of China but closely resembled that in seaports in Taiwan, and the SEO identified was genetically linked to Taiwanese SEO strains. These results substantiate our hypotheses, and suggest that the epidemiology of hantavirus infection in Taiwan are different from that in China, where the HTN and SEO strains and HFRS concurrently prevail.

Gene expression after intrarenal injection of plasmid DNA in the rat

Effective gene therapy requires efficient delivery and expression of the necessary genetic information to the target tissue. We demonstrate here that plasmid DNA, injected as naked, uncomplexed DNA into the cortical region of rat kidney, or intravenously, is localized and expressed in the kidney. The plasmid pRSVZ contained the Rous sarcoma virus promoter and a reporter gene, the beta-galactosidase gene, derived from bacteria. The beta-galactosidase gene hydrolyzes the artificial substrate X-gal to produce an intense blue color in cells that have taken up and expressed the plasmid genes. We have used X-gal staining and Western blotting to study plasmid gene expression 1, 4, and 8 days and 6 months after intrarenal injection of 50 microg of plasmid DNA and at 1 and 4 days after intravenous injection. Expression was apparent in the kidneys and several other tissues 24 h after injection and persisted for at least 8 days; expressed proteins could still be detected in the injected kidney 6 months later. These observations were corroborated by use of a plasmid, pEGFP-Puro, harboring the cytomegalovirus promoter in conjunction with a different reporter gene, the green fluorescent protein (GFP). Histological localization and Western blotting analysis of GFP expression after intrarenal injection of pEGFP-Puro paralleled results obtained with the plasmid pRSVZ. Our findings support the suggestion that intrarenal or intravenous injection of naked plasmid DNA may be an effective means of delivering therapeutic genes to the kidney and several other tissues.

Phospholipase A(2) activity, heat shock protein, and superoxide dismutase in rat remnant kidney

Male Sprague-Dawley rats (150-200 g) were randomly assigned to sham operation (n=6) or 5/6 nephrectomy (n=12) procedures. Two weeks after the completion of the 5/6 nephrectomy, these animals were again randomly assigned to two groups: non-treatment or treatment with vitamin E supplementation at 200 IU/kg chow. Two weeks later, all animals were sacrificed and the kidneys harvested. The secretory phospholipase A(2) (PLA(2)) activity was elevated (150%) in the untreated remnant kidney but returned to sham values in the vitamin E-treated kidneys. The cytoprotective heat shock protein (HSP70) and the intracellular antioxidant superoxide dismutase (MnSOD, Cu/ZnSOD) were similar in sham, remnant, and vitamin E-treated remnant kidneys. We conclude that the sudden reduction of renal mass secondary to the 5/6 nephrectomy procedure stimulates PLA(2) activity but not HSP70, MnSOD, or Cu/ZnSOD. This increased activity of PLA(2) in the remnant kidney returned to sham values after vitamin E treatment. The intrinsic cellular antioxidant enzymes, MnSOD, Cu/ZnSOD, as well as the cytoprotective heat shock protein HSP70, showed no significant changes in either vitamin E-treated or untreated kidneys compared with sham. These data are suggestive that the elevation of PLA(2) is a specific and localized response to the sudden reduction of renal mass.

Increase of leptin levels following exogenous administration of estrogen in women with normal menstruation

To investigate the acute effect of exogenous estrogen on the changes of leptin production, the time sequence of changes in plasma leptin concentration were determined following i.v. administration of premarin, a conjugated estrogen, during the follicular phase (days 5-9) in women (n = 12) with normal menstruation. The mean circulating estradiol level abruptly (P < 0.0001) increased from 4 h to a level of 72-fold from baseline and was still significantly (P < 0.05) elevated at 72 h after injection of conjugated estrogen. The mean leptin level showed a significant (P < 0.05) gradual increase from 24 h (10.8 +/- 1.0 ng/mL) continuing on up to a peak at 32 h (11.6 +/- 0.9 ng/mL); significantly (P < 0.05) sustained to 48 h (10.7 +/- 0.7 ng/mL) and then slowly decreased at 56 h after injection of premarin, as compared with the preinjection level (7.8 +/- 0.7 ng/mL). However, there were no changes of leptin levels in women (n = 10) who received normal saline injection. These data clearly suggest that a higher level of estrogen could stimulate the increase of plasma leptin concentration during the follicular phase of normal cyclic women. This result provides evidence that supraphysiological level of estrogen may act on the adipocyte to modulate leptin production through the endocrine mechanism.

Difference of plasma leptin levels in venous and arterial cord blood: relation to neonatal and placental weight

To investigate the physiological significance of umbilical plasma leptin in the fetal growth and its possible origin of production during pregnancy, plasma leptin concentrations in venous and arterial cord bloods were measured in 42 neonates (male = 23, female = 19, gestational age 36-41 weeks, birth weight 2600-4000 g). Leptin concentrations in umbilical veins (5.65 +/- 0.53 ng/mL, n = 42) and umbilical arteries (0.56 +/- 0.07 ng/mL, n = 42) were significantly (P < 0.001) lower than those in maternal peripheral veins (22.36 +/- 1.06 ng/mL, n = 42). Mean plasma leptin concentration (+/- SEM) in venous cord blood was significantly (P < 0.001) higher than that of arterial cord blood. There was significantly positive correlation (r = 0.447, P < 0.01) between umbilical venous leptin levels and neonatal body mass index (BMI). A positive correlation (r = 0.435, P < 0.01) was also found between umbilical arterial leptin and neonate BMI. There was no positive correlation between umbilical leptin levels in venous cord blood and placental weight. We thus conclude that umbilical plasma leptin may play an essential role in the fetal growth and metabolism during pregnancy and placenta is one of the major sources of leptin production, but the level of leptin in umbilico-placental circulation is independent of the weight of placenta.

Increase of maternal plasma leptin concentrations during pregnancy: comparison with nonpregnant women

To investigate the physiological changes of leptin levels and whether placenta is linked to its production during pregnancy, plasma of 65 pregnant women at various gestational weeks were compared with those of 34 age- and body mass index (BMI)-matched nonpregnant women in the study. The leptin levels showed a gradual increase from 7-13 gestational week, then continuously elevated during weeks 14-20, 21-27, 28-34, virtually reaching a peak at 35-41 weeks' gestation. When they were compared to those of age- and BMI-matched nonpregnant women, a significant (P < 0.0001) increase was found with every gestational week. There were positive correlations between maternal leptin and BMI of first (7-13th week), second (14-27th week) and third (28-41st week) trimesters, with the correlation coefficients of 0.40 (P < 0.05), 0.54 (P < 0.001), and 0.49 (P < 0.001), respectively. No correlation (r = -0.17, P > 0.05, n = 31) was found between maternal leptin level and the neonatal birth weight. These data suggest that placental production of leptin is one major source of higher levels in maternal circulating leptin other than maternal gain of fat mass and that maternal leptin level is not related to fetal birth weight during pregnancy.

Changes of circulating leptin levels during normal menstrual cycle: relationship to estradiol and progesterone

A possible role of ovarian steroids on the modulation of leptin production has recently been suggested. To investigate the relationship between leptin and ovarian steroids during the normal menstrual cycle, twenty-three healthy, normal-weight women were enrolled in the study. Blood was collected into chilled EDTA tubes on cycle days (D) 3, 7, 10, preovulatory (D13-15), midluteal (D 21-23) and late luteal (D 25-27) phases. Plasma leptin, estradiol (E2), progesterone (P), luteinizing hormone (LH) and follicle-stimulating hormone (FSH) were measured by RIA. Leptin levels showed no significant changes throughout the follicular (D7 and D10), preovulatory (8.6 +/- 0.5 ng/mL), midluteal (8.9 +/- 0.6 ng/mL) and late luteal (7.7 +/- 0.4 ng/mL) phases, as compared with those of D3 (7.4 +/- 0.5 ng/mL) level. There was no positive correlation between leptin and E2 levels in D 3 and D 7 (r = 0.14, P > 0.05) or in D 10 and preovulatory day (r = 0.25, P > 0.05). Also, no positive correlation between leptin and E2 (r = 0.12, P > 0.05) or leptin and P (r = 0.17, P > 0.05) levels were observed in the mid- and late luteal phases. These data clearly indicate that physiological alterations of circulating E2 and P concentrations have no significant influence on the leptin changes during normal menstrual cycle.

Lipoleiomyoma of the uterus

Uterine lipoleiomyoma may associate with certain concomitant metabolic disorders. The possible clinical correlates and the potential implications on the pathogenesis are elaborated.